The beneficial effect of a speaker's gestures on the listener's memory for action phrases: The pivotal role of the listener's premotor cortex.

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Ianì, Francesco; Burin, Dalila; Salatino, Adriana; Pia, Lorenzo; Ricci, Raffaella; Bucciarelli, Monica

2018-04-10

Memory for action phrases improves in the listeners when the speaker accompanies them with gestures compared to when the speaker stays still. Since behavioral studies revealed a pivotal role of the listeners' motor system, we aimed to disentangle the role of primary motor and premotor cortices. Participants had to recall phrases uttered by a speaker in two conditions: in the gesture condition, the speaker performed gestures congruent with the action; in the no-gesture condition, the speaker stayed still. In Experiment 1, half of the participants underwent inhibitory rTMS over the hand/arm region of the left premotor cortex (PMC) and the other half over the hand/arm region of the left primary motor cortex (M1). The enactment effect disappeared only following rTMS over PMC. In Experiment 2, we detected the usual enactment effect after rTMS over vertex, thereby excluding possible nonspecific rTMS effects. These findings suggest that the information encoded in the premotor cortex is a crucial part of the memory trace. Copyright © 2018 Elsevier Inc. All rights reserved.

Effect of transcranial magnetic stimulation (TMS on parietal and premotor cortex during planning of reaching movements.

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Pierpaolo Busan

Full Text Available BACKGROUND: Cerebral activation during planning of reaching movements occurs both in the superior parietal lobule (SPL and premotor cortex (PM, and their activation seems to take place in parallel. METHODOLOGY: The activation of the SPL and PM has been investigated using transcranial magnetic stimulation (TMS during planning of reaching movements under visual guidance. PRINCIPAL FINDINGS: A facilitory effect was found when TMS was delivered on the parietal cortex at about half of the time from sight of the target to hand movement, independently of target location in space. Furthermore, at the same stimulation time, a similar facilitory effect was found in PM, which is probably related to movement preparation. CONCLUSIONS: This data contributes to the understanding of cortical dynamics in the parieto-frontal network, and suggests that it is possible to interfere with the planning of reaching movements at different cortical points within a particular time window. Since similar effects may be produced at similar times on both the SPL and PM, parallel processing of visuomotor information is likely to take place in these regions.

Premotor activations in response to visually presented single letters depend on the hand used to write: a study on left-handers.

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Longcamp, Marieke; Anton, Jean-Luc; Roth, Muriel; Velay, Jean-Luc

2005-01-01

In a previous fMRI study on right-handers (Rhrs), we reported that part of the left ventral premotor cortex (BA6) was activated when alphabetical characters were passively observed and that the same region was also involved in handwriting [Longcamp, M., Anton, J. L., Roth, M., & Velay, J. L. (2003). Visual presentation of single letters activates a premotor area involved in writing. NeuroImage, 19, 1492-1500]. We therefore suggested that letter-viewing may induce automatic involvement of handwriting movements. In the present study, in order to confirm this hypothesis, we carried out a similar fMRI experiment on a group of left-handed subjects (Lhrs). We reasoned that if the above assumption was correct, visual perception of letters by Lhrs might automatically activate cortical motor areas coding for left-handed writing movements, i.e., areas located in the right hemisphere. The visual stimuli used here were either single letters, single pseudoletters, or a control stimulus. The subjects were asked to watch these stimuli attentively, and no response was required. The results showed that a ventral premotor cortical area (BA6) in the right hemisphere was specifically activated when Lhrs looked at letters and not at pseudoletters. This right area was symmetrically located with respect to the left one activated under the same circumstances in Rhrs. This finding supports the hypothesis that visual perception of written language evokes covert motor processes. In addition, a bilateral area, also located in the premotor cortex (BA6), but more ventrally and medially, was found to be activated in response to both letters and pseudoletters. This premotor region, which was not activated correspondingly in Rhrs, might be involved in the processing of graphic stimuli, whatever their degree of familiarity.

Dorsal premotor cortex: neural correlates of reach target decisions based on a color-location matching rule and conflicting sensory evidence

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Coallier, Émilie; Michelet, Thomas; Kalaska, John F.

2015-01-01

We recorded single-neuron activity in dorsal premotor (PMd) and primary motor cortex (M1) of two monkeys in a reach-target selection task. The monkeys chose between two color-coded potential targets by determining which target's color matched the predominant color of a multicolored checkerboard-like Decision Cue (DC). Different DCs contained differing numbers of colored squares matching each target. The DCs provided evidence about the correct target ranging from unambiguous (one color only) t...

Decoding a Decision Process in the Neuronal Population of Dorsal Premotor Cortex.

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Rossi-Pool, Román; Zainos, Antonio; Alvarez, Manuel; Zizumbo, Jerónimo; Vergara, José; Romo, Ranulfo

2017-12-20

When trained monkeys discriminate the temporal structure of two sequential vibrotactile stimuli, dorsal premotor cortex (DPC) showed high heterogeneity among its neuronal responses. Notably, DPC neurons coded stimulus patterns as broader categories and signaled them during working memory, comparison, and postponed decision periods. Here, we show that such population activity can be condensed into two major coding components: one that persistently represented in working memory both the first stimulus identity and the postponed informed choice and another that transiently coded the initial sensory information and the result of the comparison between the two stimuli. Additionally, we identified relevant signals that coded the timing of task events. These temporal and task-parameter readouts were shown to be strongly linked to the monkeys' behavior when contrasted to those obtained in a non-demanding cognitive control task and during error trials. These signals, hidden in the heterogeneity, were prominently represented by the DPC population response. Copyright © 2017 Elsevier Inc. All rights reserved.

Disrupting the ventral premotor cortex interferes with the contribution of action observation to use-dependent plasticity.

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Cantarero, Gabriela; Galea, Joseph M; Ajagbe, Loni; Salas, Rachel; Willis, Jeff; Celnik, Pablo

2011-12-01

Action observation (AO), observing another individual perform an action, has been implicated in several higher cognitive processes including forming basic motor memories. Previous work has shown that physical practice (PP) results in cortical motor representational changes, referred to as use-dependent plasticity (UDP), and that AO combined with PP potentiates UDP in both healthy adults and stroke patients. In humans, AO results in activation of the ventral premotor cortex (PMv), however, whether this PMv activation has a functional contribution to UDP is not known. Here, we studied the effects disruption of PMv has on UDP when subjects performed PP combined with AO (PP + AO). Subjects participated in two randomized crossover sessions measuring the amount of UDP resulting from PP + AO while receiving disruptive (1 Hz) TMS over the fMRI-activated PMv or over frontal cortex (Sham). We found that, unlike the sham session, disruptive TMS over PMv reduced the beneficial contribution of AO to UDP. To ensure that disruption of PMv was specifically interfering with the contribution of AO and not PP, subjects completed two more control sessions where they performed only PP while receiving disruptive TMS over PMv or frontal cortex. We found that the magnitude of UDP for both control sessions was similar to PP + AO with TMS over PMv. These findings suggest that the fMRI activation found in PMv during AO studies is functionally relevant to task performance, at least for the beneficial effects that AO exerts over motor training.

Tuning-in to the beat: Aesthetic appreciation of musical rhythms correlates with a premotor activity boost.

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Kornysheva, Katja; von Cramon, D Yves; Jacobsen, Thomas; Schubotz, Ricarda I

2010-01-01

Listening to music can induce us to tune in to its beat. Previous neuroimaging studies have shown that the motor system becomes involved in perceptual rhythm and timing tasks in general, as well as during preference-related responses to music. However, the role of preferred rhythm and, in particular, of preferred beat frequency (tempo) in driving activity in the motor system remains unknown. The goals of the present functional magnetic resonance imaging (fMRI) study were to determine whether the musical rhythms that are subjectively judged as beautiful boost activity in motor-related areas and if so, whether this effect is driven by preferred tempo, the underlying pulse people tune in to. On the basis of the subjects' judgments, individual preferences were determined for the different systematically varied constituents of the musical rhythms. Results demonstrate the involvement of premotor and cerebellar areas during preferred compared to not preferred musical rhythms and indicate that activity in the ventral premotor cortex (PMv) is enhanced by preferred tempo. Our findings support the assumption that the premotor activity increase during preferred tempo is the result of enhanced sensorimotor simulation of the beat frequency. This may serve as a mechanism that facilitates the tuning-in to the beat of appealing music. 2009 Wiley-Liss, Inc.

Acute immobilisation facilitates premotor preparatory activity for the non-restrained hand when facing grasp affordances.

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Kühn, Simone; Werner, Anika; Lindenberger, Ulman; Verrel, Julius

2014-05-15

Use and non-use of body parts during goal-directed action are major forces driving reorganisation of neural processing. We investigated changes in functional brain activity resulting from acute short-term immobilisation of the dominant right hand. Informed by the concept of object affordances, we predicted that the presence or absence of a limb restraint would influence the perception of graspable objects in a laterally specific way. Twenty-three participants underwent fMRI scanning during a passive object-viewing task before the intervention as well as with and without wearing an orthosis. The right dorsal premotor cortex and the left cerebellum were more strongly activated when the handle of an object was oriented towards the left hand while the right hand was immobilised compared with a situation where the hand was not immobilised. The cluster in the premotor cortex showing an interaction between condition (with restraint, without restraint) and stimulus action side (right vs. left) overlapped with the general task vs. baseline contrast prior to the intervention, confirming its functional significance for the task. These results show that acute immobilisation of the dominant right hand leads to rapid changes of the perceived affordance of objects. We conclude that changes in action requirements lead to almost instantaneous changes in functional activation patterns, which in turn may trigger structural cortical plasticity. Copyright © 2014. Published by Elsevier Inc.

Intertrial Variability in the Premotor Cortex Accounts for Individual Differences in Peripersonal Space.

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Ferri, Francesca; Costantini, Marcello; Huang, Zirui; Perrucci, Mauro Gianni; Ferretti, Antonio; Romani, Gian Luca; Northoff, Georg

2015-12-16

We live in a dynamic environment, constantly confronted with approaching objects that we may either avoid or be forced to address. A multisensory and sensorimotor interface, the peripersonal space (PPS), mediates every physical interaction between our body and the environment. Behavioral investigations show high variability in the extension of PPS across individuals, but there is a lack of evidence on the neural underpinnings of these large individual differences. Here, we used approaching auditory stimuli and fMRI to capture the individual boundary of PPS and examine its neural underpinnings. Precisely, we tested the hypothesis that intertrial variability (ITV) in brain regions coding PPS predicts individual differences of its boundary at the behavioral level. Selectively in the premotor cortex, we found that ITV, rather than trial-averaged amplitude, of BOLD responses to far rather than near dynamic stimuli predicts the individual extension of PPS. Our results provide the first empirical support for the relevance of ITV of brain responses for individual differences in human behavior. Peripersonal space (PPS) is a multisensory and sensorimotor interface mediating every physical interaction between the body and the environment. A major characteristic of the boundary of PPS in humans is the extremely high variability of its location across individuals. We show that interindividual differences in the extension of the PPS are predicted by variability of BOLD responses in the premotor cortex to far stimuli approaching our body. Our results provide the first empirical support to the relevance of variability of evoked responses for human behavior and its variance across individuals. Copyright © 2015 the authors 0270-6474/15/3516328-12$15.00/0.

From rule to response: neuronal processes in the premotor and prefrontal cortex.

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Wallis, Jonathan D; Miller, Earl K

2003-09-01

The ability to use abstract rules or principles allows behavior to generalize from specific circumstances (e.g., rules learned in a specific restaurant can subsequently be applied to any dining experience). Neurons in the prefrontal cortex (PFC) encode such rules. However, to guide behavior, rules must be linked to motor responses. We investigated the neuronal mechanisms underlying this process by recording from the PFC and the premotor cortex (PMC) of monkeys trained to use two abstract rules: "same" or "different." The monkeys had to either hold or release a lever, depending on whether two successively presented pictures were the same or different, and depending on which rule was in effect. The abstract rules were represented in both regions, although they were more prevalent and were encoded earlier and more strongly in the PMC. There was a perceptual bias in the PFC, relative to the PMC, with more PFC neurons encoding the presented pictures. In contrast, neurons encoding the behavioral response were more prevalent in the PMC, and the selectivity was stronger and appeared earlier in the PMC than in the PFC.

The human dorsal premotor cortex facilitates the excitability of ipsilateral primary motor cortex via a short latency cortico-cortical route

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Groppa, Sergiu; Schlaak, Boris H; Münchau, Alexander

2012-01-01

In non-human primates, invasive tracing and electrostimulation studies have identified strong ipsilateral cortico-cortical connections between dorsal premotor- (PMd) and the primary motor cortex (M1(HAND) ). Here, we applied dual-site transcranial magnetic stimulation (dsTMS) to left PMd and M1......(HAND) through specifically designed minicoils to selectively probe ipsilateral PMd-to-M1(HAND) connectivity in humans. A suprathreshold test stimulus (TS) was applied to M1(HAND) producing a motor evoked potential (MEP) of about 0.5 mV in the relaxed right first dorsal interosseus muscle (FDI......) facilitation did not change as a function of CS intensity. Even at higher intensities, the CS alone failed to elicit a MEP or a cortical silent period in the pre-activated FDI, excluding a direct spread of excitation from PMd to M1(HAND). No MEP facilitation was present while CS was applied rostrally over...

It's how you get there: Walking down a virtual alley activates premotor and parietal areas

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Johanna eWagner

2014-02-01

Full Text Available Voluntary drive is crucial for motor learning, therefore we are interested in the role that motor planning plays in gait movements. In this study we examined the impact of an interactive Virtual Environment (VE feedback task on the EEG patterns during robot assisted walking. We compared walking in the VE modality to two control conditions: walking with a visual attention paradigm, in which visual stimuli were unrelated to the motor task; and walking with mirror feedback, in which participants observed their own movements. Eleven healthy participants were considered. Application of independent component analysis to the EEG revealed three independent component clusters in premotor and parietal areas showing increased activity during walking with the adaptive VE training paradigm compared to the control conditions. During the interactive VE walking task spectral power in frequency ranges 8-12Hz, 15-20Hz and 23-40Hz was significantly (p ≤ 0.05 decreased. This power decrease is interpreted as a correlate of an active cortical area. Furthermore activity in the premotor cortex revealed gait cycle related modulations significantly different (p ≤ 0.05 from baseline in the frequency range 23-40Hz during walking. These modulations were significantly (p ≤ 0.05 reduced depending on gait cycle phases in the interactive VE walking task compared to the control conditions.We demonstrate that premotor and parietal areas show increased activity during walking with the adaptive VE training paradigm, when compared to walking with mirror- and movement unrelated feedback. Previous research has related a premotor-parietal network to motor planning and motor intention. We argue that movement related interactive feedback enhances motor planning and motor intention. We hypothesize that this might improve gait recovery during rehabilitation.

Dorsal premotor cortex is involved in switching motor plans

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Pastor-Bernier, Alexandre; Tremblay, Elsa; Cisek, Paul

2012-01-01

Previous studies have shown that neural activity in primate dorsal premotor cortex (PMd) can simultaneously represent multiple potential movement plans, and that activity related to these movement options is modulated by their relative subjective desirability. These findings support the hypothesis that decisions about actions are made through a competition within the same circuits that guide the actions themselves. This hypothesis further predicts that the very same cells that guide initial decisions will continue to update their activities if an animal changes its mind. For example, if a previously selected movement option suddenly becomes unavailable, the correction will be performed by the same cells that selected the initial movement, as opposed to some different group of cells responsible for online guidance. We tested this prediction by recording neural activity in the PMd of a monkey performing an instructed-delay reach selection task. In the task, two targets were simultaneously presented and their border styles indicated whether each would be worth 1, 2, or 3 juice drops. In a random subset of trials (FREE), the monkey was allowed a choice while in the remaining trials (FORCED) one of the targets disappeared at the time of the GO signal. In FORCED-LOW trials the monkey was forced to move to the less valuable target and started moving either toward the new target (Direct) or toward the target that vanished and then curved to reach the remaining one (Curved). Prior to the GO signal, PMd activity clearly reflected the monkey's subjective preference, predicting his choices in FREE trials even with equally valued options. In FORCED-LOW trials, PMd activity reflected the switch of the monkey's plan as early as 100 ms after the GO signal, well before movement onset (MO). This confirms that the activity is not related to feedback from the movement itself, and suggests that PMd continues to participate in action selection even when the animal changes its mind on

Charting the excitability of premotor to motor connections while withholding or initiating a selected movement

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Kroeger, Johan; Bäumer, Tobias; Jonas, Melanie

2010-01-01

In 19 healthy volunteers, we used transcranial magnetic stimulation (TMS) to probe the excitability in pathways linking the left dorsal premotor cortex and right primary motor cortex and those linking the left and right motor cortex during the response delay and the reaction time period while...... subjects performed a delayed response [symbol 1 (S1) - symbol 2 (S2)] Go-NoGo reaction time task with visual cues. Conditioning TMS pulses were applied to the left premotor or left motor cortex 8 ms before a test pulse was given to the right motor cortex at 300 or 1800 ms after S1 or 150 ms after S2. S1...... coded for right-hand or left-hand movement, and S2 for release or stopping the prepared movement. Conditioning of the left premotor cortex led to interhemispheric inhibition at 300 ms post-S1, interhemispheric facilitation at 150 ms post-S2, and shorter reaction times in the move-left condition...

Post-Stroke Longitudinal Alterations of Inter-Hemispheric Correlation and Hemispheric Dominance in Mouse Pre-Motor Cortex.

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Vallone, Fabio; Lai, Stefano; Spalletti, Cristina; Panarese, Alessandro; Alia, Claudia; Micera, Silvestro; Caleo, Matteo; Di Garbo, Angelo

2016-01-01

Limited restoration of function is known to occur spontaneously after an ischemic injury to the primary motor cortex. Evidence suggests that Pre-Motor Areas (PMAs) may "take over" control of the disrupted functions. However, little is known about functional reorganizations in PMAs. Forelimb movements in mice can be driven by two cortical regions, Caudal and Rostral Forelimb Areas (CFA and RFA), generally accepted as primary motor and pre-motor cortex, respectively. Here, we examined longitudinal changes in functional coupling between the two RFAs following unilateral photothrombotic stroke in CFA (mm from Bregma: +0.5 anterior, +1.25 lateral). Local field potentials (LFPs) were recorded from the RFAs of both hemispheres in freely moving injured and naïve mice. Neural signals were acquired at 9, 16 and 23 days after surgery (sub-acute period in stroke animals) through one bipolar electrode per hemisphere placed in the center of RFA, with a ground screw over the occipital bone. LFPs were pre-processed through an efficient method of artifact removal and analysed through: spectral,cross-correlation, mutual information and Granger causality analysis. Spectral analysis demonstrated an early decrease (day 9) in the alpha band power in both the RFAs. In the late sub-acute period (days 16 and 23), inter-hemispheric functional coupling was reduced in ischemic animals, as shown by a decrease in the cross-correlation and mutual information measures. Within the gamma and delta bands, correlation measures were already reduced at day 9. Granger analysis, used as a measure of the symmetry of the inter-hemispheric causal connectivity, showed a less balanced activity in the two RFAs after stroke, with more frequent oscillations of hemispheric dominance. These results indicate robust electrophysiological changes in PMAs after stroke. Specifically, we found alterations in transcallosal connectivity, with reduced inter-hemispheric functional coupling and a fluctuating dominance

Post-Stroke Longitudinal Alterations of Inter-Hemispheric Correlation and Hemispheric Dominance in Mouse Pre-Motor Cortex.

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Fabio Vallone

Full Text Available Limited restoration of function is known to occur spontaneously after an ischemic injury to the primary motor cortex. Evidence suggests that Pre-Motor Areas (PMAs may "take over" control of the disrupted functions. However, little is known about functional reorganizations in PMAs. Forelimb movements in mice can be driven by two cortical regions, Caudal and Rostral Forelimb Areas (CFA and RFA, generally accepted as primary motor and pre-motor cortex, respectively. Here, we examined longitudinal changes in functional coupling between the two RFAs following unilateral photothrombotic stroke in CFA (mm from Bregma: +0.5 anterior, +1.25 lateral.Local field potentials (LFPs were recorded from the RFAs of both hemispheres in freely moving injured and naïve mice. Neural signals were acquired at 9, 16 and 23 days after surgery (sub-acute period in stroke animals through one bipolar electrode per hemisphere placed in the center of RFA, with a ground screw over the occipital bone. LFPs were pre-processed through an efficient method of artifact removal and analysed through: spectral,cross-correlation, mutual information and Granger causality analysis.Spectral analysis demonstrated an early decrease (day 9 in the alpha band power in both the RFAs. In the late sub-acute period (days 16 and 23, inter-hemispheric functional coupling was reduced in ischemic animals, as shown by a decrease in the cross-correlation and mutual information measures. Within the gamma and delta bands, correlation measures were already reduced at day 9. Granger analysis, used as a measure of the symmetry of the inter-hemispheric causal connectivity, showed a less balanced activity in the two RFAs after stroke, with more frequent oscillations of hemispheric dominance.These results indicate robust electrophysiological changes in PMAs after stroke. Specifically, we found alterations in transcallosal connectivity, with reduced inter-hemispheric functional coupling and a fluctuating

Continuous theta burst demonstrates a causal role of premotor homunculus in action interpretation

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Michael, John Andrew

2014-01-01

Although it is well established that regions of premotor cortex (PMC) are active during action observation, it remains controversial whether they play a causal role in action understanding. In the experiment reported here, we used off-line continuous theta-burst stimulation (cTBS) to investigate ...

Dynamic anticipatory processing of hierarchical sequential events: a common role for Broca's area and ventral premotor cortex across domains?

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Fiebach, Christian J; Schubotz, Ricarda I

2006-05-01

This paper proposes a domain-general model for the functional contribution of ventral premotor cortex (PMv) and adjacent Broca's area to perceptual, cognitive, and motor processing. We propose to understand this frontal region as a highly flexible sequence processor, with the PMv mapping sequential events onto stored structural templates and Broca's Area involved in more complex, hierarchical or hypersequential processing. This proposal is supported by reference to previous functional neuroimaging studies investigating abstract sequence processing and syntactic processing.

Joint Contribution of Left Dorsal Premotor Cortex and Supramarginal Gyrus to Rapid Action Reprogramming

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Hartwigsen, Gesa; Siebner, Hartwig R

2015-01-01

human subjects performed a spatially-precued reaction time task. RESULTS: Relative to sham rTMS, effective online perturbation of left PMd significantly impaired both the response speed and accuracy in trials that were invalidly pre-cued and required the subject to reprogram the prepared action......BACKGROUND: The rapid adaptation of actions to changes in the environment is crucial for survival. We previously demonstrated a joint contribution of left dorsal premotor cortex (PMd) and left supramarginal gyrus (SMG) to action reprogramming. However, we did not probe the contribution of PMd...... to the speed and accuracy of action reprogramming and how the functional relevance of PMd changes in the presence of a dysfunctional SMG. OBJECTIVE: This study further dissociated the unique contribution of left PMd and SMG to action reprogramming. Specifically, we tested whether the critical contribution...

Distinct neural patterns enable grasp types decoding in monkey dorsal premotor cortex

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Hao, Yaoyao; Zhang, Qiaosheng; Controzzi, Marco; Cipriani, Christian; Li, Yue; Li, Juncheng; Zhang, Shaomin; Wang, Yiwen; Chen, Weidong; Chiara Carrozza, Maria; Zheng, Xiaoxiang

2014-12-01

Objective. Recent studies have shown that dorsal premotor cortex (PMd), a cortical area in the dorsomedial grasp pathway, is involved in grasp movements. However, the neural ensemble firing property of PMd during grasp movements and the extent to which it can be used for grasp decoding are still unclear. Approach. To address these issues, we used multielectrode arrays to record both spike and local field potential (LFP) signals in PMd in macaque monkeys performing reaching and grasping of one of four differently shaped objects. Main results. Single and population neuronal activity showed distinct patterns during execution of different grip types. Cluster analysis of neural ensemble signals indicated that the grasp related patterns emerged soon (200-300 ms) after the go cue signal, and faded away during the hold period. The timing and duration of the patterns varied depending on the behaviors of individual monkey. Application of support vector machine model to stable activity patterns revealed classification accuracies of 94% and 89% for each of the two monkeys, indicating a robust, decodable grasp pattern encoded in the PMd. Grasp decoding using LFPs, especially the high-frequency bands, also produced high decoding accuracies. Significance. This study is the first to specify the neuronal population encoding of grasp during the time course of grasp. We demonstrate high grasp decoding performance in PMd. These findings, combined with previous evidence for reach related modulation studies, suggest that PMd may play an important role in generation and maintenance of grasp action and may be a suitable locus for brain-machine interface applications.

Inhibitory stimulation of the ventral premotor cortex temporarily interferes with musical beat rate preference.

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Kornysheva, Katja; von Anshelm-Schiffer, Anne-Marike; Schubotz, Ricarda I

2011-08-01

Behavioral studies suggest that preference for a beat rate (tempo) in auditory sequences is tightly linked to the motor system. However, from a neuroscientific perspective the contribution of motor-related brain regions to tempo preference in the auditory domain remains unclear. A recent fMRI study (Kornysheva et al. [2010]: Hum Brain Mapp 31:48-64) revealed that the activity increase in the left ventral premotor cortex (PMv) is associated with the preference for a tempo of a musical rhythm. The activity increase correlated with how strongly the subjects preferred a tempo. Despite this evidence, it remains uncertain whether an interference with activity in the left PMv affects tempo preference strength. Consequently, we conducted an offline repetitive transcranial magnetic stimulation (rTMS) study, in which the cortical excitability in the left PMv was temporarily reduced. As hypothesized, 0.9 Hz rTMS over the left PMv temporarily affected individual tempo preference strength depending on the individual strength of tempo preference in the control session. Moreover, PMv stimulation temporarily interfered with the stability of individual tempo preference strength within and across sessions. These effects were specific to the preference for tempo in contrast to the preference for timbre, bound to the first half of the experiment following PMv stimulation and could not be explained by an impairment of tempo recognition. Our results corroborate preceding fMRI findings and suggest that activity in the left PMv is part of a network that affects the strength of beat rate preference. Copyright © 2010 Wiley-Liss, Inc.

Left Dorsal Premotor Cortex and Supramarginal Gyrus Complement Each Other during Rapid Action Reprogramming

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Hartwigsen, Gesa; Bestmann, Sven; Ward, Nick S

2012-01-01

The ability to discard a prepared action plan in favor of an alternative action is critical when facing sudden environmental changes. We tested whether the functional contribution of left supramarginal gyrus (SMG) during action reprogramming depends on the functional integrity of left dorsal...... premotor cortex (PMd). Adopting a dual-site repetitive transcranial magnetic stimulation (rTMS) strategy, we first transiently disrupted PMd with "off-line" 1 Hz rTMS and then applied focal "on-line" rTMS to SMG while human subjects performed a spatially precued reaction time (RT) task. Effective on-line r......TMS of SMG but not sham rTMS of SMG increased errors when subjects had to reprogram their action in response to an invalid precue regardless of the type of preceding off-line rTMS. This suggests that left SMG primarily contributes to the on-line updating of actions by suppressing invalidly prepared responses...

Continuous theta-burst stimulation over the dorsal premotor cortex interferes with associative learning during object lifting.

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Nowak, Dennis A; Berner, Julia; Herrnberger, Bärbel; Kammer, Thomas; Grön, Georg; Schönfeldt-Lecuona, Carlos

2009-04-01

When lifting objects of different mass, humans scale grip force according to the expected mass. In this context, humans are able to associate a sensory cue, such as a colour, to a particular mass of an object and link this association to the grip forces necessary for lifting. Here, we study the role of the dorsal premotor cortex (PMd) in setting-up an association between a colour cue and a particular mass to be lifted. Healthy right-handed subjects used a precision grip between the index finger and thumb to lift two different masses. Colour cues provided information about which of the two masses subjects would have to lift. Subjects first performed a series of lifts with the right hand to establish a stable association between a colour cue and a mass, followed by 20sec of continuous high frequency repetitive trancranial magnetic stimulation using a recently developed protocol (continuous theta-burst stimulation, cTBS) over (i) the left primary motor cortex, (ii) the left PMd and (iii) the left occipital cortex to be commenced by another series of lifts with either the right or left hand. cTBS over the PMd, but not over the primary motor cortex or O1, disrupted the predictive scaling of isometric finger forces based on colour cues, irrespective of whether the right or left hand performed the lifts after the stimulation. Our data highlight the role of the PMd to generalize and maintain associative memory processes relevant for predictive control of grip forces during object manipulation.

Pre-motor and motor activities in early handwriting

OpenAIRE

van Zwieten, Koos Jaap

2011-01-01

Behavioural studies make use of handwritten letters’ characteristics like strokes, roundedness, etcetera. In consequence, Fisher et al. (2010) studying brain activation during rejected love, noticed typical pre-motor activity patterns, as suggested by irregular writing patterns as well, due to basal ganglia dysfunction (Mergl et al., 2004). A short historical text written in a presumably depressed mood was checked on such characteristics in the light of hypothesised finger-, and hand movement...

Early musical training is linked to gray matter structure in the ventral premotor cortex and auditory-motor rhythm synchronization performance.

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Bailey, Jennifer Anne; Zatorre, Robert J; Penhune, Virginia B

2014-04-01

Evidence in animals and humans indicates that there are sensitive periods during development, times when experience or stimulation has a greater influence on behavior and brain structure. Sensitive periods are the result of an interaction between maturational processes and experience-dependent plasticity mechanisms. Previous work from our laboratory has shown that adult musicians who begin training before the age of 7 show enhancements in behavior and white matter structure compared with those who begin later. Plastic changes in white matter and gray matter are hypothesized to co-occur; therefore, the current study investigated possible differences in gray matter structure between early-trained (ET; 7) musicians, matched for years of experience. Gray matter structure was assessed using voxel-wise analysis techniques (optimized voxel-based morphometry, traditional voxel-based morphometry, and deformation-based morphometry) and surface-based measures (cortical thickness, surface area and mean curvature). Deformation-based morphometry analyses identified group differences between ET and LT musicians in right ventral premotor cortex (vPMC), which correlated with performance on an auditory motor synchronization task and with age of onset of musical training. In addition, cortical surface area in vPMC was greater for ET musicians. These results are consistent with evidence that premotor cortex shows greatest maturational change between the ages of 6-9 years and that this region is important for integrating auditory and motor information. We propose that the auditory and motor interactions required by musical practice drive plasticity in vPMC and that this plasticity is greatest when maturation is near its peak.

Conflict processing in the anterior cingulate cortex constrains response priming.

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Pastötter, Bernhard; Hanslmayr, Simon; Bäuml, Karl-Heinz T

2010-05-01

A prominent function of the anterior cingulate cortex (ACC) is to process conflict between competing response options. In this study, we investigated the role of conflict processing in a response-priming task in which manual responses were either validly or invalidly cued. Examining electrophysiological measurements of oscillatory brain activity on the source level, we found response priming to be related to a beta power decrease in the premotor cortex and conflict processing to be linked to a theta power increase in the ACC. In particular, correlation of oscillatory brain activities in the ACC and the premotor cortex showed that conflict processing reduces response priming by slowing response time in valid trials and lowering response errors in invalid trials. This relationship emerged on a between subjects level as well as within subjects, on a single trial level. These findings suggest that conflict processing in the ACC constrains the automatic priming process. 2010 Elsevier Inc. All rights reserved.

Increased facilitatory connectivity from the pre-SMA to the left dorsal premotor cortex during pseudoword repetition

DEFF Research Database (Denmark)

Hartwigsen, Gesa; Saur, Dorothee; Price, Cathy J

2013-01-01

Previous studies have demonstrated that the repetition of pseudowords engages a network of premotor areas for articulatory planning and articulation. However, it remains unclear how these premotor areas interact and drive one another during speech production. We used fMRI with dynamic causal mode...

Human left ventral premotor cortex mediates matching of hand posture to object use.

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Guy Vingerhoets

Full Text Available Visuomotor transformations for grasping have been associated with a fronto-parietal network in the monkey brain. The human homologue of the parietal monkey region (AIP has been identified as the anterior part of the intraparietal sulcus (aIPS, whereas the putative human equivalent of the monkey frontal region (F5 is located in the ventral part of the premotor cortex (vPMC. Results from animal studies suggest that monkey F5 is involved in the selection of appropriate hand postures relative to the constraints of the task. In humans, the functional roles of aIPS and vPMC appear to be more complex and the relative contribution of each region to grasp selection remains uncertain. The present study aimed to identify modulation in brain areas sensitive to the difficulty level of tool object - hand posture matching. Seventeen healthy right handed participants underwent fMRI while observing pictures of familiar tool objects followed by pictures of hand postures. The task was to decide whether the hand posture matched the functional use of the previously shown object. Conditions were manipulated for level of difficulty. Compared to a picture matching control task, the tool object - hand posture matching conditions conjointly showed increased modulation in several left hemispheric regions of the superior and inferior parietal lobules (including aIPS, the middle occipital gyrus, and the inferior temporal gyrus. Comparison of hard versus easy conditions selectively modulated the left inferior frontal gyrus with peak activity located in its opercular part (Brodmann area (BA 44. We suggest that in the human brain, vPMC/BA44 is involved in the matching of hand posture configurations in accordance with visual and functional demands.

Low-frequency transcranial magnetic stimulation over left dorsal premotor cortex improves the dynamic control of visuospatially cued actions

DEFF Research Database (Denmark)

Ward, Nick S; Bestmann, Sven; Hartwigsen, Gesa

2010-01-01

Left rostral dorsal premotor cortex (rPMd) and supramarginal gyrus (SMG) have been implicated in the dynamic control of actions. In 12 right-handed healthy individuals, we applied 30 min of low-frequency (1 Hz) repetitive transcranial magnetic stimulation (rTMS) over left rPMd to investigate...... the involvement of left rPMd and SMG in the rapid adjustment of actions guided by visuospatial cues. After rTMS, subjects underwent functional magnetic resonance imaging while making spatially congruent button presses with the right or left index finger in response to a left- or right-sided target. Subjects were...... that left rPMd and SMG-AIP contribute toward dynamic control of actions and demonstrate that low-frequency rTMS can enhance functional coupling between task-relevant brain regions and improve some aspects of motor performance....

Greater Activity in the Frontal Cortex on Left Curves: A Vector-Based fNIRS Study of Left and Right Curve Driving.

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Noriyuki Oka

Full Text Available In the brain, the mechanisms of attention to the left and the right are known to be different. It is possible that brain activity when driving also differs with different horizontal road alignments (left or right curves, but little is known about this. We found driver brain activity to be different when driving on left and right curves, in an experiment using a large-scale driving simulator and functional near-infrared spectroscopy (fNIRS.The participants were fifteen healthy adults. We created a course simulating an expressway, comprising straight line driving and gentle left and right curves, and monitored the participants under driving conditions, in which they drove at a constant speed of 100 km/h, and under non-driving conditions, in which they simply watched the screen (visual task. Changes in hemoglobin concentrations were monitored at 48 channels including the prefrontal cortex, the premotor cortex, the primary motor cortex and the parietal cortex. From orthogonal vectors of changes in deoxyhemoglobin and changes in oxyhemoglobin, we calculated changes in cerebral oxygen exchange, reflecting neural activity, and statistically compared the resulting values from the right and left curve sections.Under driving conditions, there were no sites where cerebral oxygen exchange increased significantly more during right curves than during left curves (p > 0.05, but cerebral oxygen exchange increased significantly more during left curves (p < 0.05 in the right premotor cortex, the right frontal eye field and the bilateral prefrontal cortex. Under non-driving conditions, increases were significantly greater during left curves (p < 0.05 only in the right frontal eye field.Left curve driving was thus found to require more brain activity at multiple sites, suggesting that left curve driving may require more visual attention than right curve driving. The right frontal eye field was activated under both driving and non-driving conditions.

Greater Activity in the Frontal Cortex on Left Curves: A Vector-Based fNIRS Study of Left and Right Curve Driving

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Oka, Noriyuki; Yoshino, Kayoko; Yamamoto, Kouji; Takahashi, Hideki; Li, Shuguang; Sugimachi, Toshiyuki; Nakano, Kimihiko; Suda, Yoshihiro; Kato, Toshinori

2015-01-01

Objectives In the brain, the mechanisms of attention to the left and the right are known to be different. It is possible that brain activity when driving also differs with different horizontal road alignments (left or right curves), but little is known about this. We found driver brain activity to be different when driving on left and right curves, in an experiment using a large-scale driving simulator and functional near-infrared spectroscopy (fNIRS). Research Design and Methods The participants were fifteen healthy adults. We created a course simulating an expressway, comprising straight line driving and gentle left and right curves, and monitored the participants under driving conditions, in which they drove at a constant speed of 100 km/h, and under non-driving conditions, in which they simply watched the screen (visual task). Changes in hemoglobin concentrations were monitored at 48 channels including the prefrontal cortex, the premotor cortex, the primary motor cortex and the parietal cortex. From orthogonal vectors of changes in deoxyhemoglobin and changes in oxyhemoglobin, we calculated changes in cerebral oxygen exchange, reflecting neural activity, and statistically compared the resulting values from the right and left curve sections. Results Under driving conditions, there were no sites where cerebral oxygen exchange increased significantly more during right curves than during left curves (p > 0.05), but cerebral oxygen exchange increased significantly more during left curves (p right premotor cortex, the right frontal eye field and the bilateral prefrontal cortex. Under non-driving conditions, increases were significantly greater during left curves (p right frontal eye field. Conclusions Left curve driving was thus found to require more brain activity at multiple sites, suggesting that left curve driving may require more visual attention than right curve driving. The right frontal eye field was activated under both driving and non-driving conditions

Activation of sensory cortex by imagined genital stimulation: an fMRI analysis.

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Wise, Nan J; Frangos, Eleni; Komisaruk, Barry R

2016-01-01

During the course of a previous study, our laboratory made a serendipitous finding that just thinking about genital stimulation resulted in brain activations that overlapped with, and differed from, those generated by physical genital stimulation. This study extends our previous findings by further characterizing how the brain differentially processes physical 'touch' stimulation and 'imagined' stimulation. Eleven healthy women (age range 29-74) participated in an fMRI study of the brain response to imagined or actual tactile stimulation of the nipple and clitoris. Two additional conditions - imagined dildo self-stimulation and imagined speculum stimulation - were included to characterize the effects of erotic versus non-erotic imagery. Imagined and tactile self-stimulation of the nipple and clitoris each activated the paracentral lobule (the genital region of the primary sensory cortex) and the secondary somatosensory cortex. Imagined self-stimulation of the clitoris and nipple resulted in greater activation of the frontal pole and orbital frontal cortex compared to tactile self-stimulation of these two bodily regions. Tactile self-stimulation of the clitoris and nipple activated the cerebellum, primary somatosensory cortex (hand region), and premotor cortex more than the imagined stimulation of these body regions. Imagining dildo stimulation generated extensive brain activation in the genital sensory cortex, secondary somatosensory cortex, hippocampus, amygdala, insula, nucleus accumbens, and medial prefrontal cortex, whereas imagining speculum stimulation generated only minimal activation. The present findings provide evidence of the potency of imagined stimulation of the genitals and that the following brain regions may participate in erogenous experience: primary and secondary sensory cortices, sensory-motor integration areas, limbic structures, and components of the 'reward system'. In addition, these results suggest a mechanism by which some individuals may

Activation of sensory cortex by imagined genital stimulation: an fMRI analysis

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Nan J. Wise

2016-10-01

Full Text Available Background: During the course of a previous study, our laboratory made a serendipitous finding that just thinking about genital stimulation resulted in brain activations that overlapped with, and differed from, those generated by physical genital stimulation. Objective: This study extends our previous findings by further characterizing how the brain differentially processes physical ‘touch’ stimulation and ‘imagined’ stimulation. Design: Eleven healthy women (age range 29–74 participated in an fMRI study of the brain response to imagined or actual tactile stimulation of the nipple and clitoris. Two additional conditions – imagined dildo self-stimulation and imagined speculum stimulation – were included to characterize the effects of erotic versus non-erotic imagery. Results: Imagined and tactile self-stimulation of the nipple and clitoris each activated the paracentral lobule (the genital region of the primary sensory cortex and the secondary somatosensory cortex. Imagined self-stimulation of the clitoris and nipple resulted in greater activation of the frontal pole and orbital frontal cortex compared to tactile self-stimulation of these two bodily regions. Tactile self-stimulation of the clitoris and nipple activated the cerebellum, primary somatosensory cortex (hand region, and premotor cortex more than the imagined stimulation of these body regions. Imagining dildo stimulation generated extensive brain activation in the genital sensory cortex, secondary somatosensory cortex, hippocampus, amygdala, insula, nucleus accumbens, and medial prefrontal cortex, whereas imagining speculum stimulation generated only minimal activation. Conclusion: The present findings provide evidence of the potency of imagined stimulation of the genitals and that the following brain regions may participate in erogenous experience: primary and secondary sensory cortices, sensory-motor integration areas, limbic structures, and components of the �

Bayesian Ising approximation for learning dictionaries of multispike timing patterns in premotor neurons

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Hernandez Lahme, Damian; Sober, Samuel; Nemenman, Ilya

Important questions in computational neuroscience are whether, how much, and how information is encoded in the precise timing of neural action potentials. We recently demonstrated that, in the premotor cortex during vocal control in songbirds, spike timing is far more informative about upcoming behavior than is spike rate (Tang et al, 2014). However, identification of complete dictionaries that relate spike timing patterns with the controled behavior remains an elusive problem. Here we present a computational approach to deciphering such codes for individual neurons in the songbird premotor area RA, an analog of mammalian primary motor cortex. Specifically, we analyze which multispike patterns of neural activity predict features of the upcoming vocalization, and hence are important codewords. We use a recently introduced Bayesian Ising Approximation, which properly accounts for the fact that many codewords overlap and hence are not independent. Our results show which complex, temporally precise multispike combinations are used by individual neurons to control acoustic features of the produced song, and that these code words are different across individual neurons and across different acoustic features. This work was supported, in part, by JSMF Grant 220020321, NSF Grant 1208126, NIH Grant NS084844 and NIH Grant 1 R01 EB022872.

On the context-dependent nature of the contribution of the ventral premotor cortex to speech perception

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Tremblay, Pascale; Small, Steven L.

2011-01-01

What is the nature of the interface between speech perception and production, where auditory and motor representations converge? One set of explanations suggests that during perception, the motor circuits involved in producing a perceived action are in some way enacting the action without actually causing movement (covert simulation) or sending along the motor information to be used to predict its sensory consequences (i.e., efference copy). Other accounts either reject entirely the involvement of motor representations in perception, or explain their role as being more supportive than integral, and not employing the identical circuits used in production. Using fMRI, we investigated whether there are brain regions that are conjointly active for both speech perception and production, and whether these regions are sensitive to articulatory (syllabic) complexity during both processes, which is predicted by a covert simulation account. A group of healthy young adults (1) observed a female speaker produce a set of familiar words (perception), and (2) observed and then repeated the words (production). There were two types of words, varying in articulatory complexity, as measured by the presence or absence of consonant clusters. The simple words contained no consonant cluster (e.g. “palace”), while the complex words contained one to three consonant clusters (e.g. “planet”). Results indicate that the left ventral premotor cortex (PMv) was significantly active during speech perception and speech production but that activation in this region was scaled to articulatory complexity only during speech production, revealing an incompletely specified efferent motor signal during speech perception. The right planum temporal (PT) was also active during speech perception and speech production, and activation in this region was scaled to articulatory complexity during both production and perception. These findings are discussed in the context of current theories theory of

Orbitofrontal cortex contribution to working memory. N-back ERP study

International Nuclear Information System (INIS)

Nakao, Yoshiaki; Tamura, Toshiyo; Kodabashi, Atsushi; Fujimoto, Toshiro; Yarita, Masaru

2011-01-01

Remarkable progress in cognitive neuroscience has revealed the involvement of the prefrontal cortex and the orbitofrontal cortex in human working memory, but the orbitofrontal cortex is still one of the least understood regions in the human brain. To elucidate the contribution of the orbitofrontal cortex to human working memory, we studied electroencephalography (EEG) P300 activity in n-back task. We elicited early P3 around 300 ms and late P3 around 360 ms of P300 components in n-back event related potentials (ERP). The amplitudes of the respective peaks changed depending on the working memory load (0-back, 1-back, 2-back, 3-back). We used source analysis to evaluate the orbitofrontal cortex in P3 components. A source model was constructed with the sources seeded from fMRI meta-analysis of n-back task and additional sources in the orbitofrontal cortex and the visual cortex estimated with P100 and late P3 components in the n-back ERP. This source model had more than 99% of GOF (goodness of fit) in n-back ERP. It gave us an insight of brain activity at the positions where sources existed. Early P3 was mainly produced by the dorsolateral prefrontal cortex, the ventrolateral prefrontal cortex, the inferior parietal lobule, the medial posterior parietal and the visual cortex. Late P3 was mainly produced by the medial premotor, the lateral premotor, the frontal pole and the orbitofrontal cortex. The contribution of the frontal pole and the orbitofrontal cortex had peaks around 390 ms which were later than late P3 component. In this study, the method to evaluate the orbitofrontal cortex activity in n-back ERP was provided. Our results elicited the involvement of the orbitofrontal cortex in late P3 component of n-back ERP. (author)

Activation and connectivity patterns of the presupplementary and dorsal premotor areas during free improvisation of melodies and rhythms.

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de Manzano, Örjan; Ullén, Fredrik

2012-10-15

Free, i.e. non-externally cued generation of movement sequences is fundamental to human behavior. We have earlier hypothesized that the dorsal premotor cortex (PMD), which has been consistently implicated in cognitive aspects of planning and selection of spatial motor sequences may be particularly important for the free generation of spatial movement sequences, whereas the pre-supplementary motor area (pre-SMA), which shows increased activation during perception, learning and reproduction of temporal sequences, may contribute more to the generation of temporal structures. Here we test this hypothesis using fMRI and musical improvisation in professional pianists as a model behavior. We employed a 2 × 2 factorial design with the factors Melody (Specified/Improvised) and Rhythm (Specified/Improvised). The main effect analyses partly confirmed our hypothesis: there was a main effect of Melody in the PMD; the pre-SMA was present in the main effect of Rhythm, as predicted, as well as in the main effect of Melody. A psychophysiological interaction analysis of functional connectivity demonstrated that the correlation in activity between the pre-SMA and cerebellum was higher during rhythmic improvisation than during the other conditions. In summary, there were only subtle differences in activity level between the pre-SMA and PMD during improvisation, regardless of condition. Consequently, the free generation of rhythmic and melodic structures, appears to be largely integrated processes but the functional connectivity between premotor areas and other regions may change during free generation in response to sequence-specific spatiotemporal demands. Copyright © 2012 Elsevier Inc. All rights reserved.

Feeling the beat: premotor and striatal interactions in musicians and non-musicians during beat perception

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Grahn, Jessica A.; Rowe, James B.

2009-01-01

Little is known about the underlying neurobiology of rhythm and beat perception, despite its universal cultural importance. Here we used functional magnetic resonance imaging to study rhythm perception in musicians and non-musicians. Three conditions varied in the degree to which external reinforcement versus internal generation of the beat was required. The ‘Volume’ condition strongly externally marked the beat with volume changes, the ‘Duration’ condition marked the beat with weaker accents arising from duration changes, and the ‘Unaccented’ condition required the beat to be entirely internally generated. In all conditions, beat rhythms compared to nonbeat control rhythms revealed putamen activity. The presence of a beat was also associated with greater connectivity between the putamen and the supplementary motor area (SMA), the premotor cortex (PMC) and auditory cortex. In contrast, the type of accent within the beat conditions modulated the coupling between premotor and auditory cortex, with greater modulation for musicians than non-musicians. Importantly, the putamen's response to beat conditions was not due to differences in temporal complexity between the three rhythm conditions. We propose that a cortico-subcortical network including the putamen, SMA, and PMC is engaged for the analysis of temporal sequences and prediction or generation of putative beats, especially under conditions that may require internal generation of the beat. The importance of this system for auditory-motor interaction and development of precisely timed movement is suggested here by its facilitation in musicians. PMID:19515922

Increased activity of pre-motor network does not change the excitability of motoneurons during protracted scratch initiation

DEFF Research Database (Denmark)

Guzulaitis, Robertas; Alaburda, Aidas; Hounsgaard, Jørn Dybkjær

2013-01-01

of their intrinsic excitability. Here we employed an experimental paradigm of protracted scratch initiation in the integrated carapace-spinal cord preparation of adult turtles (Chrysemys scripta elegans). The protracted initiation of scratch network activity allows us to investigate the excitability of motoneurons...... and pre-motor network activity in the time interval from the start of sensory stimulation until the onset of scratch activity. Our results suggest that increased activity in the pre-motor network facilitates the onset of scratch episodes but does not change the excitability of motoneurons at the onset...... of scratching....

Cathodal transcranial direct current stimulation (tDCS) applied to the left premotor cortex (PMC) stabilizes a newly learned motor sequence.

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Focke, Jan; Kemmet, Sylvia; Krause, Vanessa; Keitel, Ariane; Pollok, Bettina

2017-01-01

While the primary motor cortex (M1) is involved in the acquisition the premotor cortex (PMC) has been related to over-night consolidation of a newly learned motor skill. The present study aims at investigating the possible contribution of the left PMC for the stabilization of a motor sequence immediately after acquisition as determined by susceptibility to interference. Thirty six healthy volunteers received anodal, cathodal and sham transcranial direct current stimulation (tDCS) to the left PMC either immediately prior to or during training on a serial reaction time task (SRTT) with the right hand. TDCS was applied for 10min, respectively. Reaction times were measured prior to training (t1), at the end of training (t2), and after presentation of an interfering random pattern (t3). Beyond interference from learning, the random pattern served as control condition in order to estimate general effects of tDCS on reaction times. TDCS applied during SRTT training did not result in any significant effects neither on acquisition nor on susceptibility to interference. In contrast to this, tDCS prior to SRTT training yielded an unspecific facilitation of reaction times at t2 independent of tDCS polarity. At t3, reduced susceptibility to interference was found following cathodal stimulation. The results suggest the involvement of the PMC in early consolidation and reveal a piece of evidence for the hypothesis that behavioral tDCS effects vary with the activation state of the stimulated area. Copyright © 2016. Published by Elsevier B.V.

Resting-state connectivity of pre-motor cortex reflects disability in multiple sclerosis.

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Dogonowski, A-M; Siebner, H R; Soelberg Sørensen, P; Paulson, O B; Dyrby, T B; Blinkenberg, M; Madsen, K H

2013-11-01

To characterize the relationship between motor resting-state connectivity of the dorsal pre-motor cortex (PMd) and clinical disability in patients with multiple sclerosis (MS). A total of 27 patients with relapsing-remitting MS (RR-MS) and 15 patients with secondary progressive MS (SP-MS) underwent functional resting-state magnetic resonance imaging. Clinical disability was assessed using the Expanded Disability Status Scale (EDSS). Independent component analysis was used to characterize motor resting-state connectivity. Multiple regression analysis was performed in SPM8 between the individual expression of motor resting-state connectivity in PMd and EDSS scores including age as covariate. Separate post hoc analyses were performed for patients with RR-MS and SP-MS. The EDSS scores ranged from 0 to 7 with a median score of 4.3. Motor resting-state connectivity of left PMd showed a positive linear relation with clinical disability in patients with MS. This effect was stronger when considering the group of patients with RR-MS alone, whereas patients with SP-MS showed no increase in coupling strength between left PMd and the motor resting-state network with increasing clinical disability. No significant relation between motor resting-state connectivity of the right PMd and clinical disability was detected in MS. The increase in functional coupling between left PMd and the motor resting-state network with increasing clinical disability can be interpreted as adaptive reorganization of the motor system to maintain motor function, which appears to be limited to the relapsing-remitting stage of the disease. © 2013 John Wiley & Sons A/S.

Repetitive transcranial magnetic stimulation of the left premotor/dorsolateral prefrontal cortex does not have analgesic effect on central poststroke pain.

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de Oliveira, Rogério Adas Ayres; de Andrade, Daniel Ciampi; Mendonça, Melina; Barros, Rafael; Luvisoto, Tatiana; Myczkowski, Martin Luiz; Marcolin, Marco Antonio; Teixeira, Manoel Jacobsen

2014-12-01

Central poststroke pain (CPSP) is caused by an encephalic vascular lesion of the somatosensory pathways and is commonly refractory to current pharmacologic treatments. Repetitive transcranial magnetic stimulation (rTMS) of the premotor cortex/dorsolateral prefrontal cortex (PMC/DLPFC) can change thermal pain threshold toward analgesia in healthy subjects and has analgesic effects in acute postoperative pain as well as in fibromyalgia patients. However, its effect on neuropathic pain and in CPSP, in particular, has not been assessed. The aim of this prospective, double-blind, placebo-controlled study was to evaluate the analgesic effect of PMC/DLPFC rTMS in CPSP patients. Patients were randomized into 2 groups, active (a-) rTMS and sham (s-) rTMS, and were treated with 10 daily sessions of rTMS over the left PMC/DLPFC (10 Hz, 1,250 pulses/d). Outcomes were assessed at baseline, during the stimulation phase, and at 1, 2, and 4 weeks after the last stimulation. The main outcome was pain intensity changes measured by the visual analog scale on the last stimulation day compared to baseline. Interim analysis was scheduled when the first half of the patients completed the study. The study was terminated because of a significant lack of efficacy of the active arm after 21 patients completed the whole treatment and follow-up phases. rTMS of the left PMC/DLPFC did not improve pain in CPSP. The aim of this double-blind, placebo-controlled study was to evaluate the analgesic effects of rTMS to the PMC/DLPFC in CPSP patients. An interim analysis showed a consistent lack of analgesic effect, and the study was terminated. rTMS of the PMC/DLPFC is not effective in relieving CPSP. Copyright © 2014 American Pain Society. Published by Elsevier Inc. All rights reserved.

Transcallosal connection patterns of opposite dorsal premotor regions support a lateralized specialization for action and perception

NARCIS (Netherlands)

van der Hoorn, Anouk; Potgieser, Adriaan R. E.; de Jong, Bauke M.

Lateralization of higher brain functions requires that a dominant hemisphere collects relevant information from both sides. The right dorsal premotor cortex (PMd), particularly implicated in visuomotor transformations, was hypothesized to be optimally located to converge visuospatial information

Parietal and premotor cortices: activation reflects imitation accuracy during observation, delayed imitation and concurrent imitation.

Science.gov (United States)

Krüger, Britta; Bischoff, Matthias; Blecker, Carlo; Langhanns, Christine; Kindermann, Stefan; Sauerbier, Isabell; Reiser, Mathias; Stark, Rudolf; Munzert, Jörn; Pilgramm, Sebastian

2014-10-15

This study investigated whether activation within areas belonging to the action observation and imitation network reveals a linear relation to the subsequent accuracy of imitating a bimanual rhythmic movement measured via a motion capturing system. 20 participants were scanned with functional magnetic resonance imaging (fMRI) when asked to imitate observed bimanual movements either concurrently versus with a delay (2s) or simply to observe the movements without imitation. Results showed that action observation relates to activation within classic mirror-related areas. Activation patterns were more widespread when participants were asked to imitate the movement. During observation with concurrent imitation, activation in the left inferior parietal lobe (IPL) was associated negatively with imitation accuracy. During observation in the delayed imitation condition, higher subsequent imitation accuracy was coupled with higher activation in the right superior parietal lobe (SPL) and the left parietal operculum (POp). During the delayed imitation itself, a negative association between imitation accuracy and brain activation was revealed in the right ventral premotor cortex (vPMC). We conclude that the IPL is involved in online comparison and visuospatial attention processes during imitation, the SPL provides a kinesthetic blueprint during movement observation, the POp preserves body identity, and the vPMC recruits motor representations--especially when no concurrent visual guidance is possible. Copyright © 2014 Elsevier Inc. All rights reserved.

Ipsilateral corticotectal projections from the primary, premotor and supplementary motor cortical areas in adult macaque monkeys: a quantitative anterograde tracing study

Science.gov (United States)

Fregosi, Michela; Rouiller, Eric M.

2018-01-01

The corticotectal projection from cortical motor areas is one of several descending pathways involved in the indirect control of spinal motoneurons. In non-human primates, previous studies reported that cortical projections to the superior colliculus originated from the premotor cortex and the primary motor cortex, whereas no projection originated from the supplementary motor area. The aim of the present study was to investigate and compare the properties of corticotectal projections originating from these three cortical motor areas in intact adult macaques (n=9). The anterograde tracer BDA was injected into one of these cortical areas in each animal. Individual axonal boutons, both en passant and terminaux, were charted and counted in the different layers of the ipsilateral superior colliculus. The data confirmed the presence of strong corticotectal projections from the premotor cortex. A new observation was that strong corticotectal projections were also found to originate from the supplementary motor area (its proper division). The corticotectal projection from the primary motor cortex was quantitatively less strong than that from either the premotor or supplementary motor areas. The corticotectal projection from each motor area was directed mainly to the deep layer of the superior colliculus, although its intermediate layer was also a consistent target of fairly dense terminations. The strong corticotectal projections from non-primary motor areas are in position to influence the preparation and planning of voluntary movements. PMID:28921678

Functional activity of the sensorimotor cortex and cerebellum relates to cervical dystonia symptoms.

Science.gov (United States)

Burciu, Roxana G; Hess, Christopher W; Coombes, Stephen A; Ofori, Edward; Shukla, Priyank; Chung, Jae Woo; McFarland, Nikolaus R; Wagle Shukla, Aparna; Okun, Michael S; Vaillancourt, David E

2017-09-01

Cervical dystonia (CD) is the most common type of focal dystonia, causing abnormal movements of the neck and head. In this study, we used noninvasive imaging to investigate the motor system of patients with CD and uncover the neural correlates of dystonic symptoms. Furthermore, we examined whether a commonly prescribed anticholinergic medication in CD has an effect on the dystonia-related brain abnormalities. Participants included 16 patients with CD and 16 healthy age-matched controls. We collected functional MRI scans during a force task previously shown to extensively engage the motor system, and diffusion and T1-weighted MRI scans from which we calculated free-water and brain tissue densities. The dystonia group was also scanned ca. 2 h after a 2-mg dose of trihexyphenidyl. Severity of dystonia was assessed pre- and post-drug using the Burke-Fahn-Marsden Dystonia Rating Scale. Motor-related activity in CD was altered relative to controls in the primary somatosensory cortex, cerebellum, dorsal premotor and posterior parietal cortices, and occipital cortex. Most importantly, a regression model showed that increased severity of symptoms was associated with decreased functional activity of the somatosensory cortex and increased activity of the cerebellum. Structural imaging measures did not differ between CD and controls. The single dose of trihexyphenidyl altered the fMRI signal in the somatosensory cortex but not in the cerebellum. Symptom severity was not significantly reduced post-treatment. Findings show widespread changes in functional brain activity in CD and most importantly that dystonic symptoms relate to disrupted activity in the somatosensory cortex and cerebellum. Hum Brain Mapp 38:4563-4573, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

The causal role of category-specific neuronal representations in the left ventral premotor cortex (PMv) in semantic processing.

Science.gov (United States)

Cattaneo, Zaira; Devlin, Joseph T; Salvini, Francesca; Vecchi, Tomaso; Silvanto, Juha

2010-02-01

The left ventral premotor cortex (PMv) is preferentially activated by exemplars of tools, suggestive of category specificity in this region. Here we used state-dependent transcranial magnetic stimulation (TMS) to investigate the causal role of such category-specific neuronal representations in the encoding of tool words. Priming to a category name (either "Tool" or "Animal") was used with the objective of modulating the initial activation state of this region prior to application of TMS and the presentation of the target stimulus. When the target word was an exemplar of the "Tool" category, the effects of TMS applied over PMv (but not PMd) interacted with priming history by facilitating reaction times on incongruent trials while not affecting congruent trials. This congruency/TMS interaction implies that the "Tool" and "Animal" primes had a differential effect on the initial activation state of the left PMv and implies that this region is one neural locus of category-specific behavioral priming for the "Tool" category. TMS applied over PMv had no behavioral effect when the target stimulus was an exemplar of the "Animal" category, regardless of whether the target word was congruent or incongruent with the prime. That TMS applied over the left PMv interacted with a priming effect that extended from the category name ("Tool") to exemplars of that category suggests that this region contains neuronal representation associated with a specific semantic category. Our results also demonstrate that the state-dependent effects obtained in the combination of visual priming and TMS are useful in the study of higher-level cognitive functions. Copyright (c) 2009 Elsevier Inc. All rights reserved.

The selective role of premotor cortex in speech perception: a contribution to phoneme judgements but not speech comprehension.

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Krieger-Redwood, Katya; Gaskell, M Gareth; Lindsay, Shane; Jefferies, Elizabeth

2013-12-01

Several accounts of speech perception propose that the areas involved in producing language are also involved in perceiving it. In line with this view, neuroimaging studies show activation of premotor cortex (PMC) during phoneme judgment tasks; however, there is debate about whether speech perception necessarily involves motor processes, across all task contexts, or whether the contribution of PMC is restricted to tasks requiring explicit phoneme awareness. Some aspects of speech processing, such as mapping sounds onto meaning, may proceed without the involvement of motor speech areas if PMC specifically contributes to the manipulation and categorical perception of phonemes. We applied TMS to three sites-PMC, posterior superior temporal gyrus, and occipital pole-and for the first time within the TMS literature, directly contrasted two speech perception tasks that required explicit phoneme decisions and mapping of speech sounds onto semantic categories, respectively. TMS to PMC disrupted explicit phonological judgments but not access to meaning for the same speech stimuli. TMS to two further sites confirmed that this pattern was site specific and did not reflect a generic difference in the susceptibility of our experimental tasks to TMS: stimulation of pSTG, a site involved in auditory processing, disrupted performance in both language tasks, whereas stimulation of occipital pole had no effect on performance in either task. These findings demonstrate that, although PMC is important for explicit phonological judgments, crucially, PMC is not necessary for mapping speech onto meanings.

Primary motor and premotor cortex in implicit sequence learning--evidence for competition between implicit and explicit human motor memory systems.

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Kantak, Shailesh S; Mummidisetty, Chaithanya K; Stinear, James W

2012-09-01

Implicit and explicit memory systems for motor skills compete with each other during and after motor practice. Primary motor cortex (M1) is known to be engaged during implicit motor learning, while dorsal premotor cortex (PMd) is critical for explicit learning. To elucidate the neural substrates underlying the interaction between implicit and explicit memory systems, adults underwent a randomized crossover experiment of anodal transcranial direct current stimulation (AtDCS) applied over M1, PMd or sham stimulation during implicit motor sequence (serial reaction time task, SRTT) practice. We hypothesized that M1-AtDCS during practice will enhance online performance and offline learning of the implicit motor sequence. In contrast, we also hypothesized that PMd-AtDCS will attenuate performance and retention of the implicit motor sequence. Implicit sequence performance was assessed at baseline, at the end of acquisition (EoA), and 24 h after practice (retention test, RET). M1-AtDCS during practice significantly improved practice performance and supported offline stabilization compared with Sham tDCS. Performance change from EoA to RET revealed that PMd-AtDCS during practice attenuated offline stabilization compared with M1-AtDCS and sham stimulation. The results support the role of M1 in implementing online performance gains and offline stabilization for implicit motor sequence learning. In contrast, enhancing the activity within explicit motor memory network nodes such as the PMd during practice may be detrimental to offline stabilization of the learned implicit motor sequence. These results support the notion of competition between implicit and explicit motor memory systems and identify underlying neural substrates that are engaged in this competition. © 2012 The Authors. European Journal of Neuroscience © 2012 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

Cerebral Activations Related to Writing and Drawing with Each Hand

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Potgieser, Adriaan R. E.; van der Hoorn, Anouk; de Jong, Bauke M.

2015-01-01

Background Writing is a sequential motor action based on sensorimotor integration in visuospatial and linguistic functional domains. To test the hypothesis of lateralized circuitry concerning spatial and language components involved in such action, we employed an fMRI paradigm including writing and drawing with each hand. In this way, writing-related contributions of dorsal and ventral premotor regions in each hemisphere were assessed, together with effects in wider distributed circuitry. Given a right-hemisphere dominance for spatial action, right dorsal premotor cortex dominance was expected in left-hand writing while dominance of the left ventral premotor cortex was expected during right-hand writing. Methods Sixteen healthy right-handed subjects were scanned during audition-guided writing of short sentences and simple figure drawing without visual feedback. Tapping with a pencil served as a basic control task for the two higher-order motor conditions. Activation differences were assessed with Statistical Parametric Mapping (SPM). Results Writing and drawing showed parietal-premotor and posterior inferior temporal activations in both hemispheres when compared to tapping. Drawing activations were rather symmetrical for each hand. Activations in left- and right-hand writing were left-hemisphere dominant, while right dorsal premotor activation only occurred in left-hand writing, supporting a spatial motor contribution of particularly the right hemisphere. Writing contrasted to drawing revealed left-sided activations in the dorsal and ventral premotor cortex, Broca’s area, pre-Supplementary Motor Area and posterior middle and inferior temporal gyri, without parietal activation. Discussion The audition-driven postero-inferior temporal activations indicated retrieval of virtual visual form characteristics in writing and drawing, with additional activation concerning word form in the left hemisphere. Similar parietal processing in writing and drawing pointed at a

Cerebral activations related to writing and drawing with each hand.

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Potgieser, Adriaan R E; van der Hoorn, Anouk; de Jong, Bauke M

2015-01-01

Writing is a sequential motor action based on sensorimotor integration in visuospatial and linguistic functional domains. To test the hypothesis of lateralized circuitry concerning spatial and language components involved in such action, we employed an fMRI paradigm including writing and drawing with each hand. In this way, writing-related contributions of dorsal and ventral premotor regions in each hemisphere were assessed, together with effects in wider distributed circuitry. Given a right-hemisphere dominance for spatial action, right dorsal premotor cortex dominance was expected in left-hand writing while dominance of the left ventral premotor cortex was expected during right-hand writing. Sixteen healthy right-handed subjects were scanned during audition-guided writing of short sentences and simple figure drawing without visual feedback. Tapping with a pencil served as a basic control task for the two higher-order motor conditions. Activation differences were assessed with Statistical Parametric Mapping (SPM). Writing and drawing showed parietal-premotor and posterior inferior temporal activations in both hemispheres when compared to tapping. Drawing activations were rather symmetrical for each hand. Activations in left- and right-hand writing were left-hemisphere dominant, while right dorsal premotor activation only occurred in left-hand writing, supporting a spatial motor contribution of particularly the right hemisphere. Writing contrasted to drawing revealed left-sided activations in the dorsal and ventral premotor cortex, Broca's area, pre-Supplementary Motor Area and posterior middle and inferior temporal gyri, without parietal activation. The audition-driven postero-inferior temporal activations indicated retrieval of virtual visual form characteristics in writing and drawing, with additional activation concerning word form in the left hemisphere. Similar parietal processing in writing and drawing pointed at a common mechanism by which such visually

Plasticity of premotor cortico-muscular coherence in severely impaired stroke patients with hand paralysis.

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Belardinelli, Paolo; Laer, Leonard; Ortiz, Erick; Braun, Christoph; Gharabaghi, Alireza

2017-01-01

Motor recovery in severely impaired stroke patients is often very limited. To refine therapeutic interventions for regaining motor control in this patient group, the functionally relevant mechanisms of neuronal plasticity need to be detected. Cortico-muscular coherence (CMC) may provide physiological and topographic insights to achieve this goal. Synchronizing limb movements to motor-related brain activation is hypothesized to reestablish cortico-motor control indexed by CMC. In the present study, right-handed, chronic stroke patients with right-hemispheric lesions and left hand paralysis participated in a four-week training for their left upper extremity. A brain-robot interface turned event-related beta-band desynchronization of the lesioned sensorimotor cortex during kinesthetic motor-imagery into the opening of the paralyzed hand by a robotic orthosis. Simultaneous MEG/EMG recordings and individual models from MRIs were used for CMC detection and source reconstruction of cortico-muscular connectivity to the affected finger extensors before and after the training program. The upper extremity-FMA of the patients improved significantly from 16.23 ± 6.79 to 19.52 ± 7.91 (p = 0.0015). All patients showed significantly increased CMC in the beta frequency-band, with a distributed, bi-hemispheric pattern and considerable inter-individual variability. The location of CMC changes was not correlated to the severity of the motor impairment, the motor improvement or the lesion volume. Group analysis of the cortical overlap revealed a common feature in all patients following the intervention: a significantly increased level of ipsilesional premotor CMC that extended from the superior to the middle and inferior frontal gyrus, along with a confined area of increased CMC in the contralesional premotor cortex. In conclusion, functionally relevant modulations of CMC can be detected in patients with long-term, severe motor deficits after a brain-robot assisted

Melodic Priming of Motor Sequence Performance: The Role of the Dorsal Premotor Cortex

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Marianne Anke Stephan

2016-05-01

Full Text Available The purpose of this study was to determine whether exposure to specific auditory sequences leads to the induction of new motor memories and to investigate the role of the dorsal premotor cortex (dPMC in this crossmodal learning process. Fifty-two young healthy non-musicians were familiarized with the sound to key-press mapping on a computer keyboard and tested on their baseline motor performance. Each participant received subsequently either continuous theta burst stimulation (cTBS or sham stimulation over the dPMC and was then asked to remember a 12-note melody without moving. For half of the participants, the contour of the melody memorized was congruent to a subsequently performed, but never practiced, finger movement sequence (Congruent group. For the other half, the melody memorized was incongruent to the subsequent finger movement sequence (Incongruent group. Hearing a congruent melody led to significantly faster performance of a motor sequence immediately thereafter compared to hearing an incongruent melody. In addition, cTBS speeded up motor performance in both groups, possibly by relieving motor consolidation from interference by the declarative melody memorization task. Our findings substantiate recent evidence that exposure to a movement-related tone sequence can induce specific, crossmodal encoding of a movement sequence representation. They further suggest that cTBS over the dPMC may enhance early offline procedural motor skill consolidation in cognitive states where motor consolidation would normally be disturbed by concurrent declarative memory processes. These findings may contribute to a better understanding of auditory-motor system interactions and have implications for the development of new motor rehabilitation approaches using sound and non-invasive brain stimulation as neuromodulatory tools.

Cortical activation in patients with functional hemispherectomy.

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Leonhardt, G; Bingel, U; Spiekermann, G; Kurthen, M; Müller, S; Hufnagel, A

2001-10-01

Functional hemispherectomy, a safe and effective therapeutical procedure in medically intractable epilepsy, offers the chance to investigate a strictly unilateral cortical activation in ipsilateral limb movement. We assessed the pattern of cortical activation in a group of patients following functional hemispherectomy. We measured regional cerebral blood flow (rCBF) in 6 patients postoperatively and 6 normal subjects with positron emission tomography using 15[O]H2O as a tracer. Brain activation was achieved by passive elbow movements of the affected arm. Analysis of group results and between-group comparisons were performed with statistical parametric mapping, (SPM96). In normal subjects brain activation was found contralaterally in the cranial sensorimotor cortex and the supplementary motor area and ipsilaterally in the inferior parietal cortex. In patients significant rCBF increases were found in the inferior parietal cortex, caudal sensorimotor cortex and the supplementary motor area ipsilaterally. The activation was weaker than in normal subjects. Compared with normal subjects patients showed additional activation in the premotor cortex, caudal sensorimotor cortex and the inferior parietal cortex of the remaining hemisphere. Less activation compared with normal subjects was found in the cranial sensorimotor cortex and the supplementary motor area. A functional network connecting the inferior parietal cortex, premotor cortex and the supplementary motor area as well as the existence of ipsilateral projections originating from these regions may explain why these areas are predominantly involved in reorganization confined to a single hemisphere.

Premotor and Motor Cortices Encode Reward.

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Pavan Ramkumar

Full Text Available Rewards associated with actions are critical for motivation and learning about the consequences of one's actions on the world. The motor cortices are involved in planning and executing movements, but it is unclear whether they encode reward over and above limb kinematics and dynamics. Here, we report a categorical reward signal in dorsal premotor (PMd and primary motor (M1 neurons that corresponds to an increase in firing rates when a trial was not rewarded regardless of whether or not a reward was expected. We show that this signal is unrelated to error magnitude, reward prediction error, or other task confounds such as reward consumption, return reach plan, or kinematic differences across rewarded and unrewarded trials. The availability of reward information in motor cortex is crucial for theories of reward-based learning and motivational influences on actions.

Functional imaging in pre-motor Parkinson’s disease

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Arnaldi, D.; Picco, A.; Ferrara, M.; Nobili, F.; Famà, F.; Buschiazzo, A.; Morbelli, S.; De Carli, F.

2014-01-01

Several non motor symptoms (NMS) can precede the onset of the classical motor Parkinson’s disease (PD) syndrome. The existence of pre-motor and even pre-clinical PD stages has been proposed but the best target population to be screened to disclose PD patients in a pre-clinical, thus asymptomatic, stage is still matter of debate. The REM sleep behavior disorder (RBD) often affects PD patients at different stages of the disease and could precede the onset of motor symptoms by several years. However, RBD could also precede other synucleinopathies (namely, dementia with Lewy bodies and multisystem atrophy), and less frequently could be related to other neurological conditions or remain idiopathic. Moreover, not all PD patients exhibit RBD. Despite these caveats, RBD probably represents the best feature to disclose pre-motor PD patients given its high-risk of developing a full motor syndrome. Other clinical clues in the premotor stages of PD undergoing active investigation include hyposmia, depression, and autonomic dysfunction. Effective biomarkers are needed in order to improve the diagnostic accuracy in the pre-motor stage of PD, to monitor disease progression and to plan both pharmacological and non-pharmacological intervention. Functional imaging, in particular radionuclide methodologies, has been often used to investigate dopaminergic and non-dopaminergic features as well as cortical functioning in patients with RBD in its idiopathic form (iRBD) and/or associated with PD. Recently, new tracers to image α-synuclein pathologies are under development. Functional imaging in pre-motor PD, and in particular in iRBD, could improve our knowledge about the underlying mechanisms and the neurodegenerative progress of PD

Effector-independent brain activity during motor imagery of the upper and lower limbs: an fMRI study.

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Mizuguchi, Nobuaki; Nakata, Hiroki; Kanosue, Kazuyuki

2014-10-03

We utilized functional magnetic resonance imaging (fMRI) to evaluate the common brain region of motor imagery for the right and left upper and lower limbs. The subjects were instructed to repeatedly imagined extension and flexion of the right or left hands/ankles. Brain regions, which included the supplemental motor area (SMA), premotor cortex and parietal cortex, were activated during motor imagery. Conjunction analysis revealed that the left SMA and inferior frontal gyrus (IFG)/ventral premotor cortex (vPM) were commonly activated with motor imagery of the right hand, left hand, right foot, and left foot. This result suggests that these brain regions are activated during motor imagery in an effector independent manner. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Paying attention through eye movements: a computational investigation of the premotor theory of spatial attention.

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Casarotti, Marco; Lisi, Matteo; Umiltà, Carlo; Zorzi, Marco

2012-07-01

Growing evidence indicates that planning eye movements and orienting visuospatial attention share overlapping brain mechanisms. A tight link between endogenous attention and eye movements is maintained by the premotor theory, in contrast to other accounts that postulate the existence of specific attention mechanisms that modulate the activity of information processing systems. The strong assumption of equivalence between attention and eye movements, however, is challenged by demonstrations that human observers are able to keep attention on a specific location while moving the eyes elsewhere. Here we investigate whether a recurrent model of saccadic planning can account for attentional effects without requiring additional or specific mechanisms separate from the circuits that perform sensorimotor transformations for eye movements. The model builds on the basis function approach and includes a circuit that performs spatial remapping using an "internal forward model" of how visual inputs are modified as a result of saccadic movements. Simulations show that the latter circuit is crucial to account for dissociations between attention and eye movements that may be invoked to disprove the premotor theory. The model provides new insights into how spatial remapping may be implemented in parietal cortex and offers a computational framework for recent proposals that link visual stability with remapping of attention pointers.

An fMRI study of differences in brain activity among elite, expert, and novice archers at the moment of optimal aiming.

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Kim, Woojong; Chang, Yongmin; Kim, Jingu; Seo, Jeehye; Ryu, Kwangmin; Lee, Eunkyung; Woo, Minjung; Janelle, Christopher M

2014-12-01

We investigated brain activity in elite, expert, and novice archers during a simulated archery aiming task to determine whether neural correlates of performance differ by skill level. Success in shooting sports depends on complex mental routines just before the shot, when the brain prepares to execute the movement. During functional magnetic resonance imaging, 40 elite, expert, or novice archers aimed at a simulated 70-meter-distant target and pushed a button when they mentally released the bowstring. At the moment of optimal aiming, the elite and expert archers relied primarily on a dorsal pathway, with greatest activity in the occipital lobe, temporoparietal lobe, and dorsolateral pre-motor cortex. The elites showed activity in the supplementary motor area, temporoparietal area, and cerebellar dentate, while the experts showed activity only in the superior frontal area. The novices showed concurrent activity in not only the dorsolateral pre-motor cortex but also the ventral pathways linked to the ventrolateral pre-motor cortex. The novices exhibited broad activity in the superior frontal area, inferior frontal area, ventral prefrontal cortex, primary motor cortex, superior parietal lobule, and primary somatosensory cortex. The more localized neural activity of elite and expert archers than novices permits greater efficiency in the complex processes subserved by these regions. The elite group's high activity in the cerebellar dentate indicates that the cerebellum is involved in automating simultaneous movements by integrating the sensorimotor memory enabled by greater expertise in self-paced aiming tasks. A companion article comments on and generalizes our findings.

The functional role of dorso-lateral premotor cortex during mental rotation: an event-related fMRI study separating cognitive processing steps using a novel task paradigm.

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Lamm, Claus; Windischberger, Christian; Moser, Ewald; Bauer, Herbert

2007-07-15

Subjects deciding whether two objects presented at angular disparity are identical or mirror versions of each other usually show response times that linearly increase with the angle between objects. This phenomenon has been termed mental rotation. While there is widespread agreement that parietal cortex plays a dominant role in mental rotation, reports concerning the involvement of motor areas are less consistent. From a theoretical point of view, activation in motor areas suggests that mental rotation relies upon visuo-motor rather than visuo-spatial processing alone. However, the type of information that is processed by motor areas during mental rotation remains unclear. In this study we used event-related fMRI to assess whether activation in parietal and dorsolateral premotor areas (dPM) during mental rotation is distinctively related to processing spatial orientation information. Using a newly developed task paradigm we explicitly separated the processing steps (encoding, mental rotation proper and object matching) required by mental rotation tasks and additionally modulated the amount of spatial orientation information that had to be processed. Our results show that activation in dPM during mental rotation is not strongly modulated by the processing of spatial orientation information, and that activation in dPM areas is strongest during mental rotation proper. The latter finding suggests that dPM is involved in more generalized processes such as visuo-spatial attention and movement anticipation. We propose that solving mental rotation tasks is heavily dependent upon visuo-motor processes and evokes neural processing that may be considered as an implicit simulation of actual object rotation.

Identification of Inhibitory Premotor Interneurons Activated at a Late Phase in a Motor Cycle during Drosophila Larval Locomotion.

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Yuki Itakura

Full Text Available Rhythmic motor patterns underlying many types of locomotion are thought to be produced by central pattern generators (CPGs. Our knowledge of how CPG networks generate motor patterns in complex nervous systems remains incomplete, despite decades of work in a variety of model organisms. Substrate borne locomotion in Drosophila larvae is driven by waves of muscular contraction that propagate through multiple body segments. We use the motor circuitry underlying crawling in larval Drosophila as a model to try to understand how segmentally coordinated rhythmic motor patterns are generated. Whereas muscles, motoneurons and sensory neurons have been well investigated in this system, far less is known about the identities and function of interneurons. Our recent study identified a class of glutamatergic premotor interneurons, PMSIs (period-positive median segmental interneurons, that regulate the speed of locomotion. Here, we report on the identification of a distinct class of glutamatergic premotor interneurons called Glutamatergic Ventro-Lateral Interneurons (GVLIs. We used calcium imaging to search for interneurons that show rhythmic activity and identified GVLIs as interneurons showing wave-like activity during peristalsis. Paired GVLIs were present in each abdominal segment A1-A7 and locally extended an axon towards a dorsal neuropile region, where they formed GRASP-positive putative synaptic contacts with motoneurons. The interneurons expressed vesicular glutamate transporter (vGluT and thus likely secrete glutamate, a neurotransmitter known to inhibit motoneurons. These anatomical results suggest that GVLIs are premotor interneurons that locally inhibit motoneurons in the same segment. Consistent with this, optogenetic activation of GVLIs with the red-shifted channelrhodopsin, CsChrimson ceased ongoing peristalsis in crawling larvae. Simultaneous calcium imaging of the activity of GVLIs and motoneurons showed that GVLIs' wave-like activity lagged

Is there a Premotor Phase of Essential Tremor?

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Abhishek Lenka

2017-10-01

Full Text Available Background: Essential tremor (ET is the most common tremor disorder. In addition to its hallmark feature, kinetic tremor of the upper limbs, patients may have a number of non-motor symptoms and signs (NMS. Several lines of evidence suggest that ET is a neurodegenerative disorder and certain NMS may antedate the onset of tremor. This article comprehensively reviews the evidence for the existence of a "premotor phase" of ET, and discusses plausible biological explanations and implications.Methods: A PubMed search in May 2017 identified articles for this review.Results: The existence of a premotor phase of ET gains support primarily from longitudinal data. In individuals who develop incident ET, baseline (i.e., premotor evaluations reveal greater cognitive dysfunction, a faster rate of cognitive decline, and the presence of a protective effect of education against dementia. In addition, baseline evaluations also reveal more self-reported depression, antidepressant medication use, and shorter sleep duration in individuals who eventually develop incident ET. In cross-sectional studies, certain personality traits and NMS (e.g., olfactory dysfunction also suggest the existence of a premotor phase.Discussion: There is preliminary evidence supporting the existence of a premotor phase of ET. The mechanisms are unclear; however, the presence of Lewy bodies in some ET brains in autopsy studies and involvement of multiple neural networks in ET as evident from the neuroimaging studies, are possible contributors. Most evidence is from a longitudinal cohort (Neurological Disorders of Central Spain: NEDICES; additional longitudinal studies are warranted to gain better insights into the premotor phase of ET.

Modulation of left primary motor cortex excitability after bimanual training and intermittent theta burst stimulation to left dorsal premotor cortex.

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Neva, Jason L; Vesia, Michael; Singh, Amaya M; Staines, W Richard

2014-03-15

Bimanual visuomotor movement training (BMT) enhances the excitability of human preparatory premotor and primary motor (M1) cortices compared to unimanual movement. This occurs when BMT involves mirror symmetrical movements of both upper-limbs (in-phase) but not with non-symmetrical movements (anti-phase). The neural mechanisms mediating the effect of BMT is unclear, but may involve interhemispheric connections between homologous M1 representations as well as the dorsal premotor cortices (PMd). The purpose of this study is to assess how intermittent theta burst stimulation (iTBS) of the left PMd affects left M1 excitability, and the possible combined effects of iTBS to left PMd applied before a single session of BMT. Left M1 excitability was quantified using transcranial magnetic stimulation (TMS) in terms of both the amplitudes and spatial extent of motor evoked potentials (MEPs) for the extensor carpi radialis (ECR) before and multiple time points following (1) BMT, (2) iTBS to left PMd or (3) iTBS to left PMd and BMT. Although there was not a greater increase in either specific measure of M1 excitability due to the combination of the interventions, iTBS applied before BMT showed that both the spatial extent and global MEP amplitude for the ECR became larger in parallel, whereas the spatial extent was enhanced with BMT alone and global MEP amplitude was enhanced with iTBS to left PMd alone. These results suggest that the modulation of rapid functional M1 excitability associated with BMT and iTBS of the left PMd could operate under related early markers of neuro-plastic mechanisms, which may be expressed in concurrent and distinct patterns of M1 excitability. Critically, this work may guide rehabilitation training and stimulation techniques that modulate cortical excitability after brain injury. Copyright © 2013 Elsevier B.V. All rights reserved.

Responses of primate frontal cortex neurons during natural vocal communication.

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Miller, Cory T; Thomas, A Wren; Nummela, Samuel U; de la Mothe, Lisa A

2015-08-01

The role of primate frontal cortex in vocal communication and its significance in language evolution have a controversial history. While evidence indicates that vocalization processing occurs in ventrolateral prefrontal cortex neurons, vocal-motor activity has been conjectured to be primarily subcortical and suggestive of a distinctly different neural architecture from humans. Direct evidence of neural activity during natural vocal communication is limited, as previous studies were performed in chair-restrained animals. Here we recorded the activity of single neurons across multiple regions of prefrontal and premotor cortex while freely moving marmosets engaged in a natural vocal behavior known as antiphonal calling. Our aim was to test whether neurons in marmoset frontal cortex exhibited responses during vocal-signal processing and/or vocal-motor production in the context of active, natural communication. We observed motor-related changes in single neuron activity during vocal production, but relatively weak sensory responses for vocalization processing during this natural behavior. Vocal-motor responses occurred both prior to and during call production and were typically coupled to the timing of each vocalization pulse. Despite the relatively weak sensory responses a population classifier was able to distinguish between neural activity that occurred during presentations of vocalization stimuli that elicited an antiphonal response and those that did not. These findings are suggestive of the role that nonhuman primate frontal cortex neurons play in natural communication and provide an important foundation for more explicit tests of the functional contributions of these neocortical areas during vocal behaviors. Copyright © 2015 the American Physiological Society.

A central pattern generator producing alternative outputs: pattern, strength, and dynamics of premotor synaptic input to leech heart motor neurons.

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Norris, Brian J; Weaver, Adam L; Wenning, Angela; García, Paul S; Calabrese, Ronald L

2007-11-01

The central pattern generator (CPG) for heartbeat in medicinal leeches consists of seven identified pairs of segmental heart interneurons and one unidentified pair. Four of the identified pairs and the unidentified pair of interneurons make inhibitory synaptic connections with segmental heart motor neurons. The CPG produces a side-to-side asymmetric pattern of intersegmental coordination among ipsilateral premotor interneurons corresponding to a similarly asymmetric fictive motor pattern in heart motor neurons, and asymmetric constriction pattern of the two tubular hearts, synchronous and peristaltic. Using extracellular recordings from premotor interneurons and voltage-clamp recordings of ipsilateral segmental motor neurons in 69 isolated nerve cords, we assessed the strength and dynamics of premotor inhibitory synaptic output onto the entire ensemble of heart motor neurons and the associated conduction delays in both coordination modes. We conclude that premotor interneurons establish a stereotypical pattern of intersegmental synaptic connectivity, strengths, and dynamics that is invariant across coordination modes, despite wide variations among preparations. These data coupled with a previous description of the temporal pattern of premotor interneuron activity and relative phasing of motor neuron activity in the two coordination modes enable a direct assessment of how premotor interneurons through their temporal pattern of activity and their spatial pattern of synaptic connectivity, strengths, and dynamics coordinate segmental motor neurons into a functional pattern of activity.

The relevance of pre-motor symptoms in Parkinson's disease.

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Visanji, Naomi; Marras, Connie

2015-10-01

Parkinson's disease (PD) has a wide range of non-motor symptoms including; constipation, sleep disturbance, deficits in vision and olfaction, mood disorders and cardiac autonomic dysfunction. Several of these non-motor symptoms can manifest prior to the onset of motor symptoms. Recognizing these pre-motor symptoms may enable early diagnosis of PD. Currently, no single pre-motor symptom is able to predict the development of PD with 100% sensitivity or specificity. Ongoing studies in several independent at-risk cohorts should reveal the potential of combinations of pre-motor symptoms and multi-stage screening strategies to identify individuals at increased risk of PD. PD progression may be governed by a prion-like spread of a-syn throughout the nervous system. Identifying individuals at the earliest stage will likely be critical to preventing the pathological progression of PD, highlighting the relevance of pre-motor symptoms in the future treatment of the disease.

Functional neuroimaging of recovery from motor conversion disorder: A case report.

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Dogonowski, Anne-Marie; Andersen, Kasper W; Sellebjerg, Finn; Schreiber, Karen; Madsen, Kristoffer H; Siebner, Hartwig R

2018-03-27

A patient with motor conversion disorder presented with a functional paresis of the left hand. After exclusion of structural brain damage, she was repeatedly examined with whole-brain functional magnetic resonance imaging, while she performed visually paced finger-tapping tasks. The dorsal premotor cortex showed a bilateral deactivation in the acute-subacute phase. Recovery from unilateral hand paresis was associated with a gradual increase in task-based activation of the dorsal premotor cortex bilaterally. The right medial prefrontal cortex displayed the opposite pattern, showing initial task-based activation that gradually diminished with recovery. The inverse dynamics of premotor and medial prefrontal activity over time were found during unimanual finger-tapping with the affected and non-affected hand as well as during bimanual finger-tapping. These observations suggest that reduced premotor and increased medial prefrontal activity reflect an effector-independent cortical dysfunction in conversion paresis which gradually disappears in parallel with clinical remission of paresis. The results link the medial prefrontal and dorsal premotor areas to the generation of intentional actions. We hypothesise that an excessive 'veto' signal generated in medial prefrontal cortex along with decreased premotor activity might constitute the functional substrate of conversion disorder. This notion warrants further examination in a larger group of affected patients. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Inducing homeostatic-like plasticity in human motor cortex through converging corticocortical inputs

DEFF Research Database (Denmark)

Pötter-Nerger, Monika; Fischer, Sarah; Mastroeni, Claudia

2009-01-01

Transcranial stimulation techniques have revealed homeostatic-like metaplasticity in the hand area of the human primary motor cortex (M1(HAND)) that controls stimulation-induced changes in corticospinal excitability. Here we combined two interventional protocols that induce long-term depression......TMS) of the left dorsal premotor cortex (PMD) was first applied to produce an LTP-like increase (5 Hz rTMS) or LTD-like decrease (1 Hz rTMS) in corticospinal excitability in left M1(HAND) via premotor-to-motor inputs. Following PMD rTMS, paired-associative stimulation (PAS) was applied to the right median nerve...... and left M1(HAND) to induce spike-time-dependent plasticity in sensory-to-motor inputs to left M1(HAND). We adjusted the interstimulus interval to the N20 latency of the median nerve somatosensory-evoked cortical potential to produce an LTP-like increase (PAS(N20+2ms)) or an LTD-like decrease (PAS(N20-5ms...

Working memory for vibrotactile frequencies: comparison of cortical activity in blind and sighted individuals.

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Burton, Harold; Sinclair, Robert J; Dixit, Sachin

2010-11-01

In blind, occipital cortex showed robust activation to nonvisual stimuli in many prior functional neuroimaging studies. The cognitive processes represented by these activations are not fully determined, although a verbal recognition memory role has been demonstrated. In congenitally blind and sighted (10 per group), we contrasted responses to a vibrotactile one-back frequency retention task with 5-s delays and a vibrotactile amplitude-change task; both tasks involved the same vibration parameters. The one-back paradigm required continuous updating for working memory (WM). Findings in both groups confirmed roles in WM for right hemisphere dorsolateral prefrontal (DLPFC) and dorsal/ventral attention components of posterior parietal cortex. Negative findings in bilateral ventrolateral prefrontal cortex suggested task performance without subvocalization. In bilateral occipital cortex, blind showed comparable positive responses to both tasks, whereas WM evoked large negative responses in sighted. Greater utilization of attention resources in blind were suggested as causing larger responses in dorsal and ventral attention systems, right DLPFC, and persistent responses across delays between trials in somatosensory and premotor cortex. In sighted, responses in somatosensory and premotor areas showed iterated peaks matched to stimulation trial intervals. The findings in occipital cortex of blind suggest that tactile activations do not represent cognitive operations for nonverbal WM task. However, these data suggest a role in sensory processing for tactile information in blind that parallels a similar contribution for visual stimuli in occipital cortex of sighted. © 2010 Wiley-Liss, Inc.

How does transcranial DC stimulation of the primary motor cortex alter regional neuronal activity in the human brain?

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Lang, Nicolas; Siebner, Hartwig R; Ward, Nick S; Lee, Lucy; Nitsche, Michael A; Paulus, Walter; Rothwell, John C; Lemon, Roger N; Frackowiak, Richard S

2005-07-01

Transcranial direct current stimulation (tDCS) of the primary motor hand area (M1) can produce lasting polarity-specific effects on corticospinal excitability and motor learning in humans. In 16 healthy volunteers, O positron emission tomography (PET) of regional cerebral blood flow (rCBF) at rest and during finger movements was used to map lasting changes in regional synaptic activity following 10 min of tDCS (+/-1 mA). Bipolar tDCS was given through electrodes placed over the left M1 and right frontopolar cortex. Eight subjects received anodal or cathodal tDCS of the left M1, respectively. When compared to sham tDCS, anodal and cathodal tDCS induced widespread increases and decreases in rCBF in cortical and subcortical areas. These changes in rCBF were of the same magnitude as task-related rCBF changes during finger movements and remained stable throughout the 50-min period of PET scanning. Relative increases in rCBF after real tDCS compared to sham tDCS were found in the left M1, right frontal pole, right primary sensorimotor cortex and posterior brain regions irrespective of polarity. With the exception of some posterior and ventral areas, anodal tDCS increased rCBF in many cortical and subcortical regions compared to cathodal tDCS. Only the left dorsal premotor cortex demonstrated an increase in movement related activity after cathodal tDCS, however, modest compared with the relatively strong movement-independent effects of tDCS. Otherwise, movement related activity was unaffected by tDCS. Our results indicate that tDCS is an effective means of provoking sustained and widespread changes in regional neuronal activity. The extensive spatial and temporal effects of tDCS need to be taken into account when tDCS is used to modify brain function.

Real-Time Prediction of Observed Action Requires Integrity of the Dorsal Premotor Cortex: Evidence From Repetitive Transcranial Magnetic Stimulation.

Science.gov (United States)

Brich, Louisa F M; Bächle, Christine; Hermsdörfer, Joachim; Stadler, Waltraud

2018-01-01

Studying brain mechanisms underlying the prediction of observed action, the dorsal premotor cortex (PMd) has been suggested a key area. The present study probed this notion using repetitive transcranial magnetic stimulation (rTMS) to test whether interference in this area would affect the accuracy in predicting the time course of object directed actions performed with the right hand. Young and healthy participants observed actions in short videos. These were briefly occluded from view for 600 ms and resumed immediately afterwards. The task was to continue the action mentally and to indicate after each occlusion, whether the action was resumed at the right moment (condition in-time) or shifted. In a first run, single-pulse transcranial magnetic stimulation (sTMS) was delivered over the left primary hand-area during occlusion. In the second run, rTMS over the left PMd was applied during occlusion in half of the participants [experimental group (EG)]. The control group (CG) received sham-rTMS over the same area. Under rTMS, the EG predicted less trials correctly than in the sTMS run. Sham-rTMS in the CG had no effects on prediction. The interference in PMd interacted with the type of manipulation applied to the action's time course occasionally during occlusion. The performance decrease of the EG was most pronounced in conditions in which the continuations after occlusions were too late in the action's course. The present results extend earlier findings suggesting that real-time action prediction requires the integrity of the PMd. Different functional roles of this area are discussed. Alternative interpretations consider either simulation of specific motor programming functions or the involvement of a feature-unspecific predictor.

Differential Recruitment of Parietal Cortex during Spatial and Non-spatial Reach Planning

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Pierre-Michel Bernier

2017-05-01

Full Text Available The planning of goal-directed arm reaching movements is associated with activity in the dorsal parieto-frontal cortex, within which multiple regions subserve the integration of arm- and target-related sensory signals to encode a motor goal. Surprisingly, many of these regions show sustained activity during reach preparation even when target location is not specified, i.e., when a motor goal cannot be unambiguously formed. The functional role of these non-spatial preparatory signals remains unresolved. Here this process was investigated in humans by comparing reach preparatory activity in the presence or absence of information regarding upcoming target location. In order to isolate the processes specific to reaching and to control for visuospatial attentional factors, the reaching task was contrasted to a finger movement task. Functional MRI and electroencephalography (EEG were used to characterize the spatio-temporal pattern of reach-related activity in the parieto-frontal cortex. Reach planning with advance knowledge of target location induced robust blood oxygenated level dependent and EEG responses across parietal and premotor regions contralateral to the reaching arm. In contrast, reach preparation without knowledge of target location was associated with a significant BOLD response bilaterally in the parietal cortex. Furthermore, EEG alpha- and beta-band activity was restricted to parietal scalp sites, the magnitude of the latter being correlated with reach reaction times. These results suggest an intermediate stage of sensorimotor transformations in bilateral parietal cortex when target location is not specified.

Functional neuroimaging of recovery from motor conversion disorder: A case report

DEFF Research Database (Denmark)

Dogonowski, A M; Andersen, Kasper W.; Sellebjerg, F

2018-01-01

A patient with motor conversion disorder presented with a functional paresis of the left hand. After exclusion of structural brain damage, she was repeatedly examined with whole-brain functional magnetic resonance imaging, while she performed visually paced finger-tapping tasks. The dorsal premotor...... cortex showed a bilateral deactivation in the acute-subacute phase. Recovery from unilateral hand paresis was associated with a gradual increase in task-based activation of the dorsal premotor cortex bilaterally. The right medial prefrontal cortex displayed the opposite pattern, showing initial task...... that an excessive 'veto' signal generated in medial prefrontal cortex along with decreased premotor activity might constitute the functional substrate of conversion disorder. This notion warrants further examination in a larger group of affected patients....

Misconceptions about mirror-induced motor cortex activation.

NARCIS (Netherlands)

Praamstra, P.; Torney, L.; Rawle, C.J.; Miall, R.C.

2011-01-01

Observation of self-produced hand movements through a mirror, creating an illusion of the opposite hand moving, was recently reported to induce ipsilateral motor cortex activation, that is, motor cortex activation for the hand in rest. The reported work goes far beyond earlier work on motor cortex

Action word Related to Walk Heard by the Ears Activates Visual Cortex and Superior Temporal Gyrus: An fMRI Study

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Naoyuki Osaka

2012-10-01

Full Text Available Cognitive neuroscience of language of action processing is one of the interesting issues on the cortical “seat” of word meaning and related action (Pulvermueller, 1999 Behavioral Brain Sciences 22 253–336. For example, generation of action verbs referring to various arm or leg actions (e.g., pick or kick differentially activate areas along the motor strip that overlap with those areas activated by actual movement of the fingers or feet (Hauk et al., 2004 Neuron 41 301–307. Meanwhile, mimic words like onomatopoeia have the other potential to selectively and strongly stimulate specific brain regions having a specified “seat” of action meaning. In fact, mimic words highly suggestive of laughter and gaze significantly activated the extrastriate visual /premotor cortices and the frontal eye field, respectively (Osaka et al., 2003 Neuroscience Letters 340 127–130; 2009 Neuroscience Letters 461 65–68. However, the role of a mimic word related to walk on specific brain regions has not yet been investigated. The present study showed that a mimic word highly suggestive of human walking, heard by the ears with eyes closed, significantly activated the visual cortex located in extrastriate cortex and superior temporal gyrus while hearing non-sense words that did not imply walk under the same task did not activate these areas. These areas would be a critical region for generating visual images of walking and related action.

A central pattern generator producing alternative outputs: phase relations of leech heart motor neurons with respect to premotor synaptic input.

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Norris, Brian J; Weaver, Adam L; Wenning, Angela; García, Paul S; Calabrese, Ronald L

2007-11-01

The central pattern generator (CPG) for heartbeat in leeches consists of seven identified pairs of segmental heart interneurons and one unidentified pair. Four of the identified pairs and the unidentified pair of interneurons make inhibitory synaptic connections with segmental heart motor neurons. The CPG produces a side-to-side asymmetric pattern of intersegmental coordination among ipsilateral premotor interneurons corresponding to a similarly asymmetric fictive motor pattern in heart motor neurons, and asymmetric constriction pattern of the two tubular hearts: synchronous and peristaltic. Using extracellular techniques, we recorded, in 61 isolated nerve cords, the activity of motor neurons in conjunction with the phase reference premotor heart interneuron, HN(4), and another premotor interneuron that allowed us to assess the coordination mode. These data were then coupled with a previous description of the temporal pattern of premotor interneuron activity in the two coordination modes to synthesize a global phase diagram for the known elements of the CPG and the entire motor neuron ensemble. These average data reveal the stereotypical side-to-side asymmetric patterns of intersegmental coordination among the motor neurons and show how this pattern meshes with the activity pattern of premotor interneurons. Analysis of animal-to-animal variability in this coordination indicates that the intersegmental phase progression of motor neuron activity in the midbody in the peristaltic coordination mode is the most stereotypical feature of the fictive motor pattern. Bilateral recordings from motor neurons corroborate the main features of the asymmetric motor pattern.

The Premotor theory of attention: time to move on?

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Smith, Daniel T; Schenk, Thomas

2012-05-01

Spatial attention and eye-movements are tightly coupled, but the precise nature of this coupling is controversial. The influential but controversial Premotor theory of attention makes four specific predictions about the relationship between motor preparation and spatial attention. Firstly, spatial attention and motor preparation use the same neural substrates. Secondly, spatial attention is functionally equivalent to planning goal directed actions such as eye-movements (i.e. planning an action is both necessary and sufficient for a shift of spatial attention). Thirdly, planning a goal directed action with any effector system is sufficient to trigger a shift of spatial attention. Fourthly, the eye-movement system has a privileged role in orienting visual spatial attention. This article reviews empirical studies that have tested these predictions. Contrary to predictions one and two there is evidence of anatomical and functional dissociations between endogenous spatial attention and motor preparation. However, there is compelling evidence that exogenous attention is reliant on activation of the oculomotor system. With respect to the third prediction, there is correlational evidence that spatial attention is directed to the endpoint of goal-directed actions but no direct evidence that this attention shift is dependent on motor preparation. The few studies to have directly tested the fourth prediction have produced conflicting results, so the extent to which the oculomotor system has a privileged role in spatial attention remains unclear. Overall, the evidence is not consistent with the view that spatial attention is functionally equivalent to motor preparation so the Premotor theory should be rejected, although a limited version of the Premotor theory in which only exogenous attention is dependent on motor preparation may still be tenable. A plausible alternative account is that activity in the motor system contributes to biased competition between different sensory

Comprehensive analysis of area-specific and time-dependent changes in gene expression in the motor cortex of macaque monkeys during recovery from spinal cord injury.

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Higo, Noriyuki; Sato, Akira; Yamamoto, Tatsuya; Oishi, Takao; Nishimura, Yukio; Murata, Yumi; Onoe, Hirotaka; Isa, Tadashi; Kojima, Toshio

2018-05-01

The present study aimed to assess the molecular bases of cortical compensatory mechanisms following spinal cord injury in primates. To accomplish this, comprehensive changes in gene expression were investigated in the bilateral primary motor cortex (M1), dorsal premotor cortex (PMd), and ventral premotor cortex (PMv) after a unilateral lesion of the lateral corticospinal tract (l-CST). At 2 weeks after the lesion, a large number of genes exhibited altered expression levels in the contralesional M1, which is directly linked to the lesioned l-CST. Gene ontology and network analyses indicated that these changes in gene expression are involved in the atrophy and plasticity changes observed in neurons. Orchestrated gene expression changes were present when behavioral recovery was attained 3 months after the lesion, particularly among the bilateral premotor areas, and a large number of these genes are involved in plasticity. Moreover, several genes abundantly expressed in M1 of intact monkeys were upregulated in both the PMd and PMv after the l-CST lesion. These area-specific and time-dependent changes in gene expression may underlie the molecular mechanisms of functional recovery following a lesion of the l-CST. © 2018 Wiley Periodicals, Inc.

The Effect of Lesion Size on the Organization of the Ipsilesional and Contralesional Motor Cortex.

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Touvykine, Boris; Mansoori, Babak K; Jean-Charles, Loyda; Deffeyes, Joan; Quessy, Stephan; Dancause, Numa

2016-03-01

Recovery of hand function following lesions in the primary motor cortex (M1) is associated with a reorganization of premotor areas in the ipsilesional hemisphere, and this reorganization depends on the size of the lesion. It is not clear how lesion size affects motor representations in the contralesional hemisphere and how the effects in the 2 hemispheres compare. Our goal was to study how lesion size affects motor representations in the ipsilesional and contralesional hemispheres. In rats, we induced lesions of different sizes in the caudal forelimb area (CFA), the equivalent of M1. The effective lesion volume in each animal was quantified histologically. Behavioral recovery was evaluated with the Montoya Staircase task for 28 days after the lesion. Then, the organization of the CFA and the rostral forelimb area (RFA)--the putative premotor area in rats--in the 2 cerebral hemispheres was studied with intracortical microstimulation mapping techniques. The distal forelimb representation in the RFA of both the ipsilesional and contralesional hemispheres was positively correlated with the size of the lesion. In contrast, lesion size had no effect on the contralesional CFA, and there was no relationship between movement representations in the 2 hemispheres. Finally, only the contralesional RFA was negatively correlated with chronic motor deficits of the paretic forelimb. Our data show that lesion size has comparable effects on motor representations in premotor areas of both hemispheres and suggest that the contralesional premotor cortex may play a greater role in the recovery of the paretic forelimb following large lesions. © The Author(s) 2015.

Auditory attention activates peripheral visual cortex.

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Anthony D Cate

Full Text Available BACKGROUND: Recent neuroimaging studies have revealed that putatively unimodal regions of visual cortex can be activated during auditory tasks in sighted as well as in blind subjects. However, the task determinants and functional significance of auditory occipital activations (AOAs remains unclear. METHODOLOGY/PRINCIPAL FINDINGS: We examined AOAs in an intermodal selective attention task to distinguish whether they were stimulus-bound or recruited by higher-level cognitive operations associated with auditory attention. Cortical surface mapping showed that auditory occipital activations were localized to retinotopic visual cortex subserving the far peripheral visual field. AOAs depended strictly on the sustained engagement of auditory attention and were enhanced in more difficult listening conditions. In contrast, unattended sounds produced no AOAs regardless of their intensity, spatial location, or frequency. CONCLUSIONS/SIGNIFICANCE: Auditory attention, but not passive exposure to sounds, routinely activated peripheral regions of visual cortex when subjects attended to sound sources outside the visual field. Functional connections between auditory cortex and visual cortex subserving the peripheral visual field appear to underlie the generation of AOAs, which may reflect the priming of visual regions to process soon-to-appear objects associated with unseen sound sources.

Real-Time Prediction of Observed Action Requires Integrity of the Dorsal Premotor Cortex: Evidence From Repetitive Transcranial Magnetic Stimulation

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Louisa F. M. Brich

2018-03-01

Full Text Available Studying brain mechanisms underlying the prediction of observed action, the dorsal premotor cortex (PMd has been suggested a key area. The present study probed this notion using repetitive transcranial magnetic stimulation (rTMS to test whether interference in this area would affect the accuracy in predicting the time course of object directed actions performed with the right hand. Young and healthy participants observed actions in short videos. These were briefly occluded from view for 600 ms and resumed immediately afterwards. The task was to continue the action mentally and to indicate after each occlusion, whether the action was resumed at the right moment (condition in-time or shifted. In a first run, single-pulse transcranial magnetic stimulation (sTMS was delivered over the left primary hand-area during occlusion. In the second run, rTMS over the left PMd was applied during occlusion in half of the participants [experimental group (EG]. The control group (CG received sham-rTMS over the same area. Under rTMS, the EG predicted less trials correctly than in the sTMS run. Sham-rTMS in the CG had no effects on prediction. The interference in PMd interacted with the type of manipulation applied to the action’s time course occasionally during occlusion. The performance decrease of the EG was most pronounced in conditions in which the continuations after occlusions were too late in the action’s course. The present results extend earlier findings suggesting that real-time action prediction requires the integrity of the PMd. Different functional roles of this area are discussed. Alternative interpretations consider either simulation of specific motor programming functions or the involvement of a feature-unspecific predictor.

Complex modulation of fingertip forces during precision grasp and lift after theta burst stimulation over the dorsal premotor cortex

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Drljačić Dragana

2017-01-01

Full Text Available Background/Aim. Adaptive control and fingertip force synchronization of precise grasp stability during unimanual manipulation of small objects represents an illustrative example of highly fractionated movements that are foundation of fine motor control. It is assumed that this process is controlled by several motor areas of the frontal lobe, particularly applicable to the primary motor (M-1 and dorsal premotor cortex (PMd. Aiming to examine the role of PMd during fine coordination of fingertip forces we applied theta burst repetitive magnetic stimulation (TBS to disrupt neural processing in that cortical area. Methods. Using a single-blind, randomized, crossover design, 10 healthy subjects (29 ± 3.9 years received single sessions of continuous TBS (cTBS600, intermittent TBS (iTBS600, or sham stimulation, separate from one another at least one week, over the PMd region of dominant hemisphere. Precision grasp and lift were assessed by instrumented device, recording grip (G and load (L forces, during three manipulation tasks (ramp-and-hold, oscillation force producing and simple lifting tasks, with each hand separately, before and after interventions. Results. We observed the improvement of task performance related to constant error (CE in oscillation task with the dominant hand (DH after the iTBS (p = 0.009. On the contrary, the cTBS reduced variable error (VE for non-dominant hand (NH, p = 0.005. Considering force coordination we found that iTBS worsened variables for NH (G/L ratio, p = 0.017; cross-correlation of the G and L, p = 0.047; Gain, p = 0.047. Conclusion. These results demonstrate the ability of TBS to modulate fingertip forces during precision grasping and lifting, when applied over PMd. These findings support the role of PMd in human motor control and forces generation required to hold small objects stable in our hands.

Medial cortex activity, self-reflection and depression.

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Johnson, Marcia K; Nolen-Hoeksema, Susan; Mitchell, Karen J; Levin, Yael

2009-12-01

Using functional magnetic resonance imaging, we investigated neural activity associated with self-reflection in depressed [current major depressive episode (MDE)] and healthy control participants, focusing on medial cortex areas previously shown to be associated with self-reflection. Both the MDE and healthy control groups showed greater activity in anterior medial cortex (medial frontal gyrus, anterior cingulate gyrus) when cued to think about hopes and aspirations compared with duties and obligations, and greater activity in posterior medial cortex (precuneus, posterior cingulate) when cued to think about duties and obligations (Experiment 1). However, the MDE group showed less activity than controls in the same area of medial frontal cortex when self-referential cues were more ambiguous with respect to valence (Experiment 2), and less deactivation in a non-self-referential condition in both experiments. Furthermore, individual differences in rumination were positively correlated with activity in both anterior and posterior medial cortex during non-self-referential conditions. These results provide converging evidence for a dissociation of anterior and posterior medial cortex depending on the focus of self-relevant thought. They also provide neural evidence consistent with behavioral findings that depression is associated with disruption of positively valenced thoughts in response to ambiguous cues, and difficulty disengaging from self-reflection when it is appropriate to do so.

Calretinin as a marker for premotor neurons involved in upgaze in human brainstem

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Christopher eAdamczyk

2015-12-01

Full Text Available Eye movements are generated by different premotor pathways. Damage to them can cause specific deficits of eye movements, such as saccades. For correlative clinico-anatomical post-mortem studies of cases with eye movement disorders it is essential to identify the functional cell groups of the oculomotor system in the human brain by marker proteins. Based on monkey studies, the premotor neurons of the saccadic system can be identified by the histochemical markers parvalbumin and perineuronal nets in humans. These areas involve the interstitial nucleus of Cajal (INC and the rostral interstitial nucleus of the medial longitudinal fascicle (RIMLF, which both contain premotor neurons for upgaze and downgaze. Recent monkey and human studies revealed a selective excitatory calretinin-positive input to the motoneurons mediating upgaze, but not to those for downgaze. Three premotor regions were identified as sources of calretinin input in monkey: y-group, INC and RIMLF. These findings suggest that the expression pattern of parvalbumin and calretinin may help to identify premotor neurons involved in up- or downgaze. In a post-mortem study of five human cases without neurological diseases we investigated the y-group, INC and RIMLF for the presence of parvalbumin and calretinin positive neurons including their co-expression. Adjacent thin paraffin sections were stained for the aggrecan component of perineuronal nets, parvalbumin or calretinin and glutamate decarboxylase. The comparative analysis of scanned thin sections of INC and RIMLF revealed medium-sized parvalbumin positive neurons with and without calretinin coexpression, which were intermingled. The parvalbumin/calretinin positive neurons in both nuclei are considered as excitatory premotor upgaze neurons. Accordingly, the parvalbumin-positive neurons lacking calretinin are considered as premotor downgaze neurons in RIMLF, but may in addition include inhibitory premotor upgaze neurons in the INC as

Effects of CPAP-therapy on brain electrical activity in obstructive sleep apneic patients: a combined EEG study using LORETA and Omega complexity : reversible alterations of brain activity in OSAS.

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Toth, Marton; Faludi, Bela; Kondakor, Istvan

2012-10-01

Effects of initiation of continuous positive airway pressure (CPAP) therapy on EEG background activity were investigated in patients with obstructive sleep apnea syndrome (OSAS, N = 25) to test possible reversibility of alterations of brain electrical activity caused by chronic hypoxia. Normal control group (N = 14) was also examined. Two EEG examinations were done in each groups: at night and in the next morning. Global and regional (left vs. right, anterior vs. posterior) measures of spatial complexity (Omega complexity) were used to characterize the degree of spatial synchrony of EEG. Low resolution electromagnetic tomography (LORETA) was used to localize generators of EEG activity in separate frequency bands. Before CPAP-treatment, a significantly lower Omega complexity was found globally and over the right hemisphere. Due to CPAP-treatment, these significant differences vanished. Significantly decreased Omega complexity was found in the anterior region after treatment. LORETA showed a decreased activity in all of the beta bands after therapy in the right hippocampus, premotor and temporo-parietal cortex, and bilaterally in the precuneus, paracentral and posterior cingulate cortex. No significant changes were seen in control group. Comparing controls and patients before sleep, an increased alpha2 band activity was seen bilaterally in the precuneus, paracentral and posterior cingulate cortex, while in the morning an increased beta3 band activity in the left precentral and bilateral premotor cortex and a decreased delta band activity in the right temporo-parietal cortex and insula were observed. These findings indicate that effect of sleep on EEG background activity is different in OSAS patients and normal controls. In OSAS patients, significant changes lead to a more normal EEG after a night under CPAP-treatment. Compensatory alterations of brain electrical activity in regions associated with influencing sympathetic outflow, visuospatial abilities, long

Cortical activation pattern during shoulder simple versus vibration exercises: a functional near infrared spectroscopy study.

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Jang, Sung Ho; Yeo, Sang Seok; Lee, Seung Hyun; Jin, Sang Hyun; Lee, Mi Young

2017-08-01

To date, the cortical effect of exercise has not been fully elucidated. Using the functional near infrared spectroscopy, we attempted to compare the cortical effect between shoulder vibration exercise and shoulder simple exercise. Eight healthy subjects were recruited for this study. Two different exercise tasks (shoulder vibration exercise using the flexible pole and shoulder simple exercise) were performed using a block paradigm. We measured the values of oxygenated hemoglobin in the four regions of interest: the primary sensory-motor cortex (SM1 total, arm somatotopy, and leg and trunk somatotopy), the premotor cortex, the supplementary motor area, and the prefrontal cortex. During shoulder vibration exercise and shoulder simple exercise, cortical activation was observed in SM1 (total, arm somatotopy, and leg and trunk somatotopy), premotor cortex, supplementary motor area, and prefrontal cortex. Higher oxygenated hemoglobin values were also observed in the areas of arm somatotopy of SM1 compared with those of other regions of interest. However, no significant difference in the arm somatotopy of SM1 was observed between the two exercises. By contrast, in the leg and trunk somatotopy of SM1, shoulder vibration exercise led to a significantly higher oxy-hemoglobin value than shoulder simple exercise. These two exercises may result in cortical activation effects for the motor areas relevant to the shoulder exercise, especially in the arm somatotopy of SM1. However, shoulder vibration exercise has an additional cortical activation effect for the leg and trunk somatotopy of SM1.

Cortical activation pattern during shoulder simple versus vibration exercises: a functional near infrared spectroscopy study

Directory of Open Access Journals (Sweden)

Sung Ho Jang

2017-01-01

Full Text Available To date, the cortical effect of exercise has not been fully elucidated. Using the functional near infrared spectroscopy, we attempted to compare the cortical effect between shoulder vibration exercise and shoulder simple exercise. Eight healthy subjects were recruited for this study. Two different exercise tasks (shoulder vibration exercise using the flexible pole and shoulder simple exercise were performed using a block paradigm. We measured the values of oxygenated hemoglobin in the four regions of interest: the primary sensory-motor cortex (SM1 total, arm somatotopy, and leg and trunk somatotopy, the premotor cortex, the supplementary motor area, and the prefrontal cortex. During shoulder vibration exercise and shoulder simple exercise, cortical activation was observed in SM1 (total, arm somatotopy, and leg and trunk somatotopy, premotor cortex, supplementary motor area, and prefrontal cortex. Higher oxygenated hemoglobin values were also observed in the areas of arm somatotopy of SM1 compared with those of other regions of interest. However, no significant difference in the arm somatotopy of SM1 was observed between the two exercises. By contrast, in the leg and trunk somatotopy of SM1, shoulder vibration exercise led to a significantly higher oxy-hemoglobin value than shoulder simple exercise. These two exercises may result in cortical activation effects for the motor areas relevant to the shoulder exercise, especially in the arm somatotopy of SM1. However, shoulder vibration exercise has an additional cortical activation effect for the leg and trunk somatotopy of SM1.

Right Temporoparietal Cortex Activation during Visuo-proprioceptive Conflict

DEFF Research Database (Denmark)

Balslev, Daniela; Nielsen, Finn Årup; Paulson, Olaf B.

2005-01-01

by the two modalities. Subjects felt the passive movement of the right index finger on a rectangular field and watched a cursor moving on a computer screen. Cursor and finger locations either mapped onto each other (congruent condition) or did not (incongruent condition). Monitoring incongruent compared...... with congruent movement activated the premotor area bilaterally and the right temporoparietal junction. These brain areas have previously been associated with shifts in the attended location in the visual space. These findings suggest an interaction between vision and proprioception in orienting to spatial...

Can free-viewing perceptual asymmetries be explained by scanning, pre-motor or attentional biases?

Science.gov (United States)

Nicholls, Michael E R; Roberts, Georgina R

2002-04-01

Judgments of relative magnitude between the left and right sides of a stimulus are generally weighted toward the features contained on the left side. This leftward perceptual bias could be the result of, (a) left-to-right scanning biases, (b) pre-motor activation of the right hemisphere, or (c) a left hemispatial attentional bias. The relative merits of these explanations of perceptual asymmetry were investigated. In Experiment 1, English and Hebrew readers made luminance judgements for two left/right mirror-reversed luminance gradients (greyscales task). Despite different reading/scanning habits, both groups exhibited a leftward perceptual bias. English and Hebrew readers also performed a line bisection task. Scanning biases were controlled by asking participants to follow a marker as it moved left-to-right or right-to-left and then stop it as it reached the midpoint of the line. Despite controlling scanning, a leftward bias was observed in both groups. In Experiment 2, peripheral spatial cues were presented prior to the greyscales stimuli. English readers showed a reduction in the leftward bias for right-sided cues as compared to left-sided and neutral cues. Right-side cues presumably overcame a pre-existing leftward attentional bias. In both experiments, pre-motor activation was controlled using bimanual responses. Despite this control, a leftward bias was observed throughout the study. The data support the attentional bias account of leftward perceptual biases over the scanning and pre-motor activation accounts. Whether or not unilateral hemispheric activation provides an adequate account of this attentional bias is discussed.

Connectivity changes underlying neurofeedback training of visual cortex activity.

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Frank Scharnowski

Full Text Available Neurofeedback based on real-time functional magnetic resonance imaging (fMRI is a new approach that allows training of voluntary control over regionally specific brain activity. However, the neural basis of successful neurofeedback learning remains poorly understood. Here, we assessed changes in effective brain connectivity associated with neurofeedback training of visual cortex activity. Using dynamic causal modeling (DCM, we found that training participants to increase visual cortex activity was associated with increased effective connectivity between the visual cortex and the superior parietal lobe. Specifically, participants who learned to control activity in their visual cortex showed increased top-down control of the superior parietal lobe over the visual cortex, and at the same time reduced bottom-up processing. These results are consistent with efficient employment of top-down visual attention and imagery, which were the cognitive strategies used by participants to increase their visual cortex activity.

When action turns into words. Activation of motor-based knowledge during categorization of manipulable objects

DEFF Research Database (Denmark)

Gerlach, Christian; Law, Ian; Paulson, Olaf B

2002-01-01

Functional imaging studies have demonstrated that processing of man-made objects activate the left ventral premotor cortex, which is known to be concerned with motor function. This has led to the suggestion that the comprehension of man-made objects may rely on motor-based knowledge of object uti...

Midcingulate cortex: Structure, connections, homologies, functions and diseases.

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Vogt, Brent A

2016-07-01

Midcingulate cortex (MCC) has risen in prominence as human imaging identifies unique structural and functional activity therein and this is the first review of its structure, connections, functions and disease vulnerabilities. The MCC has two divisions (anterior, aMCC and posterior, pMCC) that represent functional units and the cytoarchitecture, connections and neurocytology of each is shown with immunohistochemistry and receptor binding. The MCC is not a division of anterior cingulate cortex (ACC) and the "dorsal ACC" designation is a misnomer as it incorrectly implies that MCC is a division of ACC. Interpretation of findings among species and developing models of human diseases requires detailed comparative studies which is shown here for five species with flat maps and immunohistochemistry (human, monkey, rabbit, rat, mouse). The largest neurons in human cingulate cortex are in layer Vb of area 24 d in pMCC which project to the spinal cord. This area is part of the caudal cingulate premotor area which is involved in multisensory orientation of the head and body in space and neuron responses are tuned for the force and direction of movement. In contrast, the rostral cingulate premotor area in aMCC is involved in action-reinforcement associations and selection based on the amount of reward or aversive properties of a potential movement. The aMCC is activated by nociceptive information from the midline, mediodorsal and intralaminar thalamic nuclei which evoke fear and mediates nocifensive behaviors. This subregion also has high dopaminergic afferents and high dopamine-1 receptor binding and is engaged in reward processes. Opposing pain/avoidance and reward/approach functions are selected by assessment of potential outcomes and error detection according to feedback-mediated, decision making. Parietal afferents differentially terminate in MCC and provide for multisensory control in an eye- and head-centric manner. Finally, MCC vulnerability in human disease confirms

Decoding 3D reach and grasp from hybrid signals in motor and premotor cortices: spikes, multiunit activity, and local field potentials.

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Bansal, Arjun K; Truccolo, Wilson; Vargas-Irwin, Carlos E; Donoghue, John P

2012-03-01

Neural activity in motor cortex during reach and grasp movements shows modulations in a broad range of signals from single-neuron spiking activity (SA) to various frequency bands in broadband local field potentials (LFPs). In particular, spatiotemporal patterns in multiband LFPs are thought to reflect dendritic integration of local and interareal synaptic inputs, attentional and preparatory processes, and multiunit activity (MUA) related to movement representation in the local motor area. Nevertheless, the relationship between multiband LFPs and SA, and their relationship to movement parameters and their relative value as brain-computer interface (BCI) control signals, remain poorly understood. Also, although this broad range of signals may provide complementary information channels in primary (MI) and ventral premotor (PMv) areas, areal differences in information have not been systematically examined. Here, for the first time, the amount of information in SA and multiband LFPs was compared for MI and PMv by recording from dual 96-multielectrode arrays while monkeys made naturalistic reach and grasp actions. Information was assessed as decoding accuracy for 3D arm end point and grip aperture kinematics based on SA or LFPs in MI and PMv, or combinations of signal types across areas. In contrast with previous studies with ≤16 simultaneous electrodes, here ensembles of >16 units (on average) carried more information than multiband, multichannel LFPs. Furthermore, reach and grasp information added by various LFP frequency bands was not independent from that in SA ensembles but rather typically less than and primarily contained within the latter. Notably, MI and PMv did not show a particular bias toward reach or grasp for this task or for a broad range of signal types. For BCIs, our results indicate that neuronal ensemble spiking is the preferred signal for decoding, while LFPs and combined signals from PMv and MI can add robustness to BCI control.

Inhibitory and facilitatory connectivity from ventral premotor to primary motor cortex in healthy humans at rest--a bifocal TMS study

DEFF Research Database (Denmark)

Bäumer, T; Schippling, S; Kroeger, J

2009-01-01

in ipsilateral M1 excitability was located at the border between ventral Brodmann area (BA) 6 and BA 44, the human homologue of monkey's PMv (area F5). CONCLUSION: We infer that the corticospinal motor output from M1 to contralateral hand muscles can be facilitated or inhibited by a CS over ipsilateral PMv....... SIGNIFICANCE: The fact that conditioning effects following PMd stimulation differ from those after PMv stimulation supports the concept that inputs from premotor cortices to M1 are functionally segregated....

Heterozygous carriers of a Parkin or PINK1 mutation share a common functional endophenotype

DEFF Research Database (Denmark)

van Nuenen, BF; Siebner, Hartwig; Weiss, MM

2008-01-01

inherited Parkinson disease alters the cortical control of sequential finger movements. METHODS: Nonmanifesting individuals carrying a single heterozygous Parkin (n = 13) or PINK1 (n = 9) mutation and 23 healthy controls without these mutations were studied with functional MRI (fMRI). During f...... rostral dorsal premotor cortex in mutation carriers but not in controls. Task-related activation of these premotor areas was similar in carriers of a Parkin or PINK1 mutation. CONCLUSION: Mutations in different genes linked to recessively inherited Parkinson disease are associated with an additional...... recruitment of rostral supplementary motor area and rostral dorsal premotor cortex during a simple motor sequence task. These premotor areas were recruited independently of the underlying genotype. The observed activation most likely reflects a "generic" compensatory mechanism to maintain motor function...

Neural correlates of skill acquisition: decreased cortical activity during a serial interception sequence learning task.

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Gobel, Eric W; Parrish, Todd B; Reber, Paul J

2011-10-15

Learning of complex motor skills requires learning of component movements as well as the sequential structure of their order and timing. Using a Serial Interception Sequence Learning (SISL) task, participants learned a sequence of precisely timed interception responses through training with a repeating sequence. Following initial implicit learning of the repeating sequence, functional MRI data were collected during performance of that known sequence and compared with activity evoked during novel sequences of actions, novel timing patterns, or both. Reduced activity was observed during the practiced sequence in a distributed bilateral network including extrastriate occipital, parietal, and premotor cortical regions. These reductions in evoked activity likely reflect improved efficiency in visuospatial processing, spatio-motor integration, motor planning, and motor execution for the trained sequence, which is likely supported by nondeclarative skill learning. In addition, the practiced sequence evoked increased activity in the left ventral striatum and medial prefrontal cortex, while the posterior cingulate was more active during periods of better performance. Many prior studies of perceptual-motor skill learning have found increased activity in motor areas of the frontal cortex (e.g., motor and premotor cortex, SMA) and striatal areas (e.g., the putamen). The change in activity observed here (i.e., decreased activity across a cortical network) may reflect skill learning that is predominantly expressed through more accurate performance rather than decreased reaction time. Copyright © 2011 Elsevier Inc. All rights reserved.

An Activation Likelihood Estimation Meta-Analysis Study of Simple Motor Movements in Older and Young Adults

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Turesky, Ted K.; Turkeltaub, Peter E.; Eden, Guinevere F.

2016-01-01

The functional neuroanatomy of finger movements has been characterized with neuroimaging in young adults. However, less is known about the aging motor system. Several studies have contrasted movement-related activity in older versus young adults, but there is inconsistency among their findings. To address this, we conducted an activation likelihood estimation (ALE) meta-analysis on within-group data from older adults and young adults performing regularly paced right-hand finger movement tasks in response to external stimuli. We hypothesized that older adults would show a greater likelihood of activation in right cortical motor areas (i.e., ipsilateral to the side of movement) compared to young adults. ALE maps were examined for conjunction and between-group differences. Older adults showed overlapping likelihoods of activation with young adults in left primary sensorimotor cortex (SM1), bilateral supplementary motor area, bilateral insula, left thalamus, and right anterior cerebellum. Their ALE map differed from that of the young adults in right SM1 (extending into dorsal premotor cortex), right supramarginal gyrus, medial premotor cortex, and right posterior cerebellum. The finding that older adults uniquely use ipsilateral regions for right-hand finger movements and show age-dependent modulations in regions recruited by both age groups provides a foundation by which to understand age-related motor decline and motor disorders. PMID:27799910

Dissociating the role of prefrontal and premotor cortices in controlling inhibitory mechanisms during motor preparation.

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Duque, Julie; Labruna, Ludovica; Verset, Sophie; Olivier, Etienne; Ivry, Richard B

2012-01-18

Top-down control processes are critical to select goal-directed actions in flexible environments. In humans, these processes include two inhibitory mechanisms that operate during response selection: one is involved in solving a competition between different response options, the other ensures that a selected response is initiated in a timely manner. Here, we evaluated the role of dorsal premotor cortex (PMd) and lateral prefrontal cortex (LPF) of healthy subjects in these two forms of inhibition by using an innovative transcranial magnetic stimulation (TMS) protocol combining repetitive TMS (rTMS) over PMd or LPF and a single pulse TMS (sTMS) over primary motor cortex (M1). sTMS over M1 allowed us to assess inhibitory changes in corticospinal excitability, while rTMS was used to produce transient disruption of PMd or LPF. We found that rTMS over LPF reduces inhibition associated with competition resolution, whereas rTMS over PMd decreases inhibition associated with response impulse control. These results emphasize the dissociable contributions of these two frontal regions to inhibitory control during motor preparation. The association of LPF with competition resolution is consistent with the role of this area in relatively abstract aspects of control related to goal maintenance, ensuring that the appropriate response is selected in a variable context. In contrast, the association of PMd with impulse control is consistent with the role of this area in more specific processes related to motor preparation and initiation.

Dissociating the role of prefrontal and premotor cortices in controlling inhibitory mechanisms during motor preparation

Science.gov (United States)

Duque, Julie; Labruna, Ludovica; Verset, Sophie; Olivier, Etienne; Ivry, Richard B.

2012-01-01

Top-down control processes are critical to select goal-directed actions in flexible environments. In humans, these processes include two inhibitory mechanisms that operate during response selection: one is involved in solving a competition between different response options, the other ensures that a selected response is initiated timely. Here, we evaluated the role of dorsal premotor cortex (PMd) and lateral prefrontal cortex (LPF) of healthy subjects in these two forms of inhibition by using an innovative transcranial magnetic stimulation (TMS) protocol combining repetitive TMS (rTMS) over PMd or LPF and a single pulse TMS (sTMS) over primary motor cortex (M1). sTMS over M1 allowed us to assess inhibitory changes in corticospinal excitability, while rTMS was used to produce transient disruption of PMd or LPF. We found that rTMS over LPF reduces inhibition associated with competition resolution whereas rTMS over PMd decreases inhibition associated with response impulse control. These results emphasize the dissociable contributions of these two frontal regions to inhibitory control during motor preparation. The association of LPF with competition resolution is consistent with the role of this area in relatively abstract aspects of control related to goal maintenance, ensuring that the appropriate response is selected in a variable context. In contrast, the association of PMd with impulse control is consistent with the role of this area in more specific processes related to motor preparation and initiation. PMID:22262879

Right Temporoparietal Cortex Activation during Visuo-proprioceptive Conflict

DEFF Research Database (Denmark)

Balslev, Daniela; Nielsen, Finn Årup; Paulson, Olaf B.

2005-01-01

with congruent movement activated the premotor area bilaterally and the right temporoparietal junction. These brain areas have previously been associated with shifts in the attended location in the visual space. These findings suggest an interaction between vision and proprioception in orienting to spatial......The conflict between vision and proprioception has been proposed to explain why healthy subjects perform worse than proprioceptively deafferented patients in conditions with optical displacement, e.g. novel mirror drawing. It is not known which brain processes depend upon the successful integration...... of visual and proprioceptive information and are therefore impaired when these modalities disagree. With fMRI in healthy subjects we compared brain activity across two conditions with similar visual and proprioceptive stimulation and similar task demands that differed by the congruence of movement showed...

Left cytoarchitectonic BA 44 processes syntactic gender violations in determiner phrases.

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Heim, Stefan; van Ermingen, Muna; Huber, Walter; Amunts, Katrin

2010-10-01

Recent neuroimaging studies make contradictory predictions about the involvement of left Brodmann's area (BA) 44 in processing local syntactic violations in determiner phrases (DPs). Some studies suggest a role for BA 44 in detecting local syntactic violations, whereas others attribute this function to the left premotor cortex. Therefore, the present event-related functional magnetic resonance imaging (fMRI) study investigated whether left-cytoarchitectonic BA 44 was activated when German DPs involving syntactic gender violations were compared with correct DPs (correct: 'der Baum'-the[masculine] tree[masculine]; violated: 'das Baum'--the[neuter] tree[masculine]). Grammaticality judgements were made for both visual and auditory DPs to be able to generalize the results across modalities. Grammaticality judgements involved, among others, left BA 44 and left BA 6 in the premotor cortex for visual and auditory stimuli. Most importantly, activation in left BA 44 was consistently higher for violated than for correct DPs. This finding was behaviourally corroborated by longer reaction times for violated versus correct DPs. Additional brain regions, showing the same effect, included left premotor cortex, supplementary motor area, right middle and superior frontal cortex, and left cerebellum. Based on earlier findings from the literature, the results indicate the involvement of left BA 44 in processing local syntactic violations when these include morphological features, whereas left premotor cortex seems crucial for the detection of local word category violations. © 2010 Wiley-Liss, Inc.

Storage and executive processes in the frontal lobes.

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Smith, E E; Jonides, J

1999-03-12

The human frontal cortex helps mediate working memory, a system that is used for temporary storage and manipulation of information and that is involved in many higher cognitive functions. Working memory includes two components: short-term storage (on the order of seconds) and executive processes that operate on the contents of storage. Recently, these two components have been investigated in functional neuroimaging studies. Studies of storage indicate that different frontal regions are activated for different kinds of information: storage for verbal materials activates Broca's area and left-hemisphere supplementary and premotor areas; storage of spatial information activates the right-hemisphere premotor cortex; and storage of object information activates other areas of the prefrontal cortex. Two of the fundamental executive processes are selective attention and task management. Both processes activate the anterior cingulate and dorsolateral prefrontal cortex.

Serum BDNF correlates with connectivity in the (pre)motor hub in the aging human brain--a resting-state fMRI pilot study.

Science.gov (United States)

Mueller, Karsten; Arelin, Katrin; Möller, Harald E; Sacher, Julia; Kratzsch, Jürgen; Luck, Tobias; Riedel-Heller, Steffi; Villringer, Arno; Schroeter, Matthias L

2016-02-01

Brain-derived neurotrophic factor (BDNF) has been discussed to be involved in plasticity processes in the human brain, in particular during aging. Recently, aging and its (neurodegenerative) diseases have increasingly been conceptualized as disconnection syndromes. Here, connectivity changes in neural networks (the connectome) are suggested to be the most relevant and characteristic features for such processes or diseases. To further elucidate the impact of aging on neural networks, we investigated the interaction between plasticity processes, brain connectivity, and healthy aging by measuring levels of serum BDNF and resting-state fMRI data in 25 young (mean age 24.8 ± 2.7 (SD) years) and 23 old healthy participants (mean age, 68.6 ± 4.1 years). To identify neural hubs most essentially related to serum BDNF, we applied graph theory approaches, namely the new data-driven and parameter-free approach eigenvector centrality (EC) mapping. The analysis revealed a positive correlation between serum BDNF and EC in the premotor and motor cortex in older participants in contrast to young volunteers, where we did not detect any association. This positive relationship between serum BDNF and EC appears to be specific for older adults. Our results might indicate that the amount of physical activity and learning capacities, leading to higher BDNF levels, increases brain connectivity in (pre)motor areas in healthy aging in agreement with rodent animal studies. Pilot results have to be replicated in a larger sample including behavioral data to disentangle the cause for the relationship between BDNF levels and connectivity. Copyright © 2016 Elsevier Inc. All rights reserved.

Bringing up the rear: new premotor interneurons add regional complexity to a segmentally distributed motor pattern

Science.gov (United States)

Norris, Brian J.; Doloc-Mihu, Anca; Calabrese, Ronald L.

2011-01-01

Central pattern generators (CPGs) pace and pattern many rhythmic activities. We have uncovered a new module in the heartbeat CPG of leeches that creates a regional difference in this segmentally distributed motor pattern. The core CPG consists of seven identified pairs and one unidentified pair of heart interneurons of which 5 pairs are premotor and inhibit 16 pairs of heart motor neurons. The heartbeat CPG produces a side-to-side asymmetric pattern of activity of the premotor heart interneurons corresponding to an asymmetric fictive motor pattern and an asymmetric constriction pattern of the hearts with regular switches between the two sides. The premotor pattern progresses from rear to front on one side and nearly synchronously on the other; the motor pattern shows corresponding intersegmental coordination, but only from segment 15 forward. In the rearmost segments the fictive motor pattern and the constriction pattern progress from front to rear on both sides and converge in phase. Modeling studies suggested that the known inhibitory inputs to the rearmost heart motor neurons were insufficient to account for this activity. We therefore reexamined the constriction pattern of intact leeches. We also identified electrophysiologically two additional pairs of heart interneurons in the rear. These new heart interneurons make inhibitory connections with the rear heart motor neurons, are coordinated with the core heartbeat CPG, and are dye-coupled to their contralateral homologs. Their strong inhibitory connections with the rearmost heart motor neurons and the small side-to-side phase difference of their bursting contribute to the different motor and beating pattern observed in the animal's rear. PMID:21775711

Prefrontal cortex activity during swallowing in dysphagia patients.

Science.gov (United States)

Lee, Jun; Yamate, Chisato; Taira, Masato; Shinoda, Masamichi; Urata, Kentaro; Maruno, Mitsuru; Ito, Reio; Saito, Hiroto; Gionhaku, Nobuhito; Iinuma, Toshimitsu; Iwata, Koichi

2018-05-24

Prefrontal cortex activity is modulated by flavor and taste stimuli and changes during swallowing. We hypothesized that changes in the modulation of prefrontal cortex activity by flavor and taste were associated with swallowing movement and evaluated brain activity during swallowing in patients with dysphagia. To evaluate prefrontal cortex activity in dysphagia patients during swallowing, change in oxidized hemoglobin (z-score) was measured with near-infrared spectroscopy while dysphagia patients and healthy controls swallowed sweetened/unsweetened and flavored/unflavored jelly. Total z-scores were positive during swallowing of flavored/unsweetened jelly and negative during swallowing of unflavored/sweetened jelly in controls but negative during swallowing of sweetened/unsweetened and flavored/unflavored jelly in dysphagia patients. These findings suggest that taste and flavor during food swallowing are associated with positive and negative z-scores, respectively. Change in negative and positive z-scores may be useful in evaluating brain activity of dysphagia patients during swallowing of sweetened and unsweetened food.

An emotion-based facial expression word activates laughter module in the human brain: a functional magnetic resonance imaging study.

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Osaka, Naoyuki; Osaka, Mariko; Kondo, Hirohito; Morishita, Masanao; Fukuyama, Hidenao; Shibasaki, Hiroshi

2003-04-10

We report an fMRI experiment demonstrating that visualization of onomatopoeia, an emotion-based facial expression word, highly suggestive of laughter, heard by the ear, significantly activates both the extrastriate visual cortex near the inferior occipital gyrus and the premotor (PM)/supplementary motor area (SMA) in the superior frontal gyrus while non-onomatopoeic words under the same task that did not imply laughter do not activate these areas in humans. We tested the specific hypothesis that an activation in extrastriate visual cortex and PM/SMA would be modulated by image formation of onomatopoeia implying laughter and found the hypothesis to be true. Copyright 2003 Elsevier Science Ireland Ltd.

Symmetry of fMRI activation in the primary sensorimotor cortex during unilateral chewing.

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Lotze, M; Domin, M; Kordass, B

2017-05-01

Functional magnetic resonance imaging (fMRI) is one of the most advanced techniques to analyze the cerebral effects on many behavior aspects of the oral system such as chewing and mastication. Studies on imaging of the cerebral representation of chewing demonstrated differential results with respect to cortical lateralization during unilateral chewing. The aim of our study is to clarify the effects of cerebral responses during unilateral chewing. We used fMRI to compare brain activities during occlusal function in centric occlusion on natural teeth and chewing on a gum located on the right or the left teeth in 15 healthy subjects. Group data were performed by Talairach normalization and in addition by an assignment of activation maxima to individual anatomical landmarks in order to avoid possible loss of spatial preciseness of activation sites by normalization procedures. Evaluation of group data by Talairach normalization revealed representation sites for occlusal movements in bilateral primary (S1) and secondary (S2) somatosensory cortices, primary motor (M1) and premotor cortices, supplementary motor area (SMA) and medial cingulate gyrus, bilateral anterior cerebellar hemispheres and vermis, insula, orbitofrontal cortex, thalamus, and left pallidum. Right-sided chewing showed no differential activation to left-sided chewing, and both showed activation in areas also involved in bilateral occlusion. Both techniques, the one based on group normalization and the one based on an individual evaluation method, revealed remarkable low differences in activation maximum location in the primary motor, the primary and secondary somatosensory cortices, and the anterior cerebellar lobe. All chewing movements tested involved bilateral sensorimotor activation without a significant lateralization of activation intensities. Overall, a general lateralization of occlusion movements to the dominant side could not be verified in the present study. Chewing on the left or on the right

Seven years of recording from monkey cortex with a chronically implanted multiple microelectrode

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Jürgen Krüger

2010-05-01

Full Text Available A brush of 64 microwires was chronically implanted in the ventral premotor cortex of a macaque monkey. Contrary to common approaches, the wires were inserted from the white matter side. This approach, by avoiding mechanical pressure on the dura and pia mater during penetration, disturbed only minimally the cortical recording site. With this approach isolated potentials and multiunit activity were recorded for more than seven years in about one third of electrodes. The indirect insertion method also provided an excellent stability within each recording session, and in some cases even allowed recording from the same neurons for several years. Histological examination of the implanted brain region shows only a very marginal damage the recording area. Advantages and problems related to long-term recording are discussed.

Asymmetric Functional Connectivity of the Contra- and Ipsilateral Secondary Somatosensory Cortex during Tactile Object Recognition

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Yinghua Yu

2018-01-01

Full Text Available In the somatosensory system, it is well known that the bilateral secondary somatosensory cortex (SII receives projections from the unilateral primary somatosensory cortex (SI, and the SII, in turn, sends feedback projections to SI. Most neuroimaging studies have clearly shown bilateral SII activation using only unilateral stimulation for both anatomical and functional connectivity across SII subregions. However, no study has unveiled differences in the functional connectivity of the contra- and ipsilateral SII network that relates to frontoparietal areas during tactile object recognition. Therefore, we used event-related functional magnetic resonance imaging (fMRI and a delayed match-to-sample (DMS task to investigate the contributions of bilateral SII during tactile object recognition. In the fMRI experiment, 14 healthy subjects were presented with tactile angle stimuli on their right index finger and asked to encode three sample stimuli during the encoding phase and one test stimulus during the recognition phase. Then, the subjects indicated whether the angle of test stimulus was presented during the encoding phase. The results showed that contralateral (left SII activity was greater than ipsilateral (right SII activity during the encoding phase, but there was no difference during the recognition phase. A subsequent psycho-physiological interaction (PPI analysis revealed distinct connectivity from the contra- and ipsilateral SII to other regions. The left SII functionally connected to the left SI and right primary and premotor cortex, while the right SII functionally connected to the left posterior parietal cortex (PPC. Our findings suggest that in situations involving unilateral tactile object recognition, contra- and ipsilateral SII will induce an asymmetrical functional connectivity to other brain areas, which may occur by the hand contralateral effect of SII.

Avalanche analysis from multi-electrode ensemble recordings in cat, monkey and human cerebral cortex during wakefulness and sleep.

Directory of Open Access Journals (Sweden)

Nima eDehghani

2012-08-01

Full Text Available Self-organized critical states are found in many natural systems, from earthquakes to forest fires, they have also been observed in neural systems, particularly, in neuronal cultures. However, the presence of critical states in the awake brain remains controversial. Here, we compared avalanche analyses performed on different in vivo preparations during wakefulness, slow-wave sleep and REM sleep, using high-density electrode arrays in cat motor cortex (96 electrodes, monkey motor cortex and premotor cortex and human temporal cortex (96 electrodes in epileptic patients. In neuronal avalanches defined from units (up to 160 single units, the size of avalanches never clearly scaled as power-law, but rather scaled exponentially or displayed intermediate scaling. We also analyzed the dynamics of local field potentials (LFPs and in particular LFP negative peaks (nLFPs among the different electrodes (up to 96 sites in temporal cortex or up to 128 sites in adjacent motor and pre-motor cortices. In this case, the avalanches defined from nLFPs displayed power-law scaling in double logarithmic representations, as reported previously in monkey. However, avalanche defined as positive LFP (pLFP peaks, which are less directly related to neuronal firing, also displayed apparent power-law scaling. Closer examination of this scaling using the more reliable cumulative distribution function (CDF and other rigorous statistical measures, did not confirm power-law scaling. The same pattern was seen for cats, monkey and human, as well as for different brain states of wakefulness and sleep. We also tested other alternative distributions. Multiple exponential fitting yielded optimal fits of the avalanche dynamics with bi-exponential distributions. Collectively, these results show no clear evidence for power-law scaling or self-organized critical states in the awake and sleeping brain of mammals, from cat to man.

High-order motor cortex in rats receives somatosensory inputs from the primary motor cortex via cortico-cortical pathways.

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Kunori, Nobuo; Takashima, Ichiro

2016-12-01

The motor cortex of rats contains two forelimb motor areas; the caudal forelimb area (CFA) and the rostral forelimb area (RFA). Although the RFA is thought to correspond to the premotor and/or supplementary motor cortices of primates, which are higher-order motor areas that receive somatosensory inputs, it is unknown whether the RFA of rats receives somatosensory inputs in the same manner. To investigate this issue, voltage-sensitive dye (VSD) imaging was used to assess the motor cortex in rats following a brief electrical stimulation of the forelimb. This procedure was followed by intracortical microstimulation (ICMS) mapping to identify the motor representations in the imaged cortex. The combined use of VSD imaging and ICMS revealed that both the CFA and RFA received excitatory synaptic inputs after forelimb stimulation. Further evaluation of the sensory input pathway to the RFA revealed that the forelimb-evoked RFA response was abolished either by the pharmacological inactivation of the CFA or a cortical transection between the CFA and RFA. These results suggest that forelimb-related sensory inputs would be transmitted to the RFA from the CFA via the cortico-cortical pathway. Thus, the present findings imply that sensory information processed in the RFA may be used for the generation of coordinated forelimb movements, which would be similar to the function of the higher-order motor cortex in primates. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

False memory for context activates the parahippocampal cortex.

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Karanian, Jessica M; Slotnick, Scott D

2014-01-01

Previous studies have reported greater activity in the parahippocampal cortex during true memory than false memory, which has been interpreted as reflecting greater sensory processing during true memory. However, in these studies, sensory detail and contextual information were confounded. In the present fMRI study, we employed a novel paradigm to dissociate these factors. During encoding, abstract shapes were presented in one of two contexts (i.e., moving or stationary). During retrieval, participants classified shapes as previously "moving" or "stationary." Critically, contextual processing was relatively greater during false memory ("moving" responses to stationary items), while sensory processing was relatively greater during true memory ("moving" responses to moving items). Within the medial temporal lobe, false memory versus true memory produced greater activity in the parahippocampal cortex, whereas true memory versus false memory produced greater activity in the hippocampus. The present results indicate that the parahippocampal cortex mediates contextual processing rather than sensory processing.

How specialized are writing-specific brain regions? An fMRI study of writing, drawing and oral spelling.

Science.gov (United States)

Planton, Samuel; Longcamp, Marieke; Péran, Patrice; Démonet, Jean-François; Jucla, Mélanie

2017-03-01

Several brain imaging studies identified brain regions that are consistently involved in writing tasks; the left premotor and superior parietal cortices have been associated with the peripheral components of writing performance as opposed to other regions that support the central, orthographic components. Based on a meta-analysis by Planton, Jucla, Roux, and Demonet (2013), we focused on five such writing areas and questioned the task-specificity and hemispheric lateralization profile of the brain response in an functional magnetic resonance imaging (fMRI) experiment where 16 right-handed participants wrote down, spelled out orally object names, and drew shapes from object pictures. All writing-related areas were activated by drawing, and some of them by oral spelling, thus questioning their specialization for written production. The graphemic/motor frontal area (GMFA), a subpart of the superior premotor cortex close to Exner's area (Roux et al., 2009), was the only area with a writing-specific lateralization profile, that is, clear left lateralization during handwriting, and bilateral activity during drawing. Furthermore, the relative lateralization and levels of activation in the superior parietal cortex, ventral premotor cortex, ventral occipitotemporal cortex and right cerebellum across the three tasks brought out new evidence regarding their respective contributions to the writing processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Regulating prefrontal cortex activation

DEFF Research Database (Denmark)

Aznar, Susana; Klein, Anders Bue

2013-01-01

The prefrontal cortex (PFC) is involved in mediating important higher-order cognitive processes such as decision making, prompting thereby our actions. At the same time, PFC activation is strongly influenced by emotional reactions through its functional interaction with the amygdala...... of emotion-based actions, such as addiction and other impulse-related behaviors. In this review, we give an overview of the 5-HT2A receptor distribution (neuronal, intracellular, and anatomical) along with its functional and physiological effect on PFC activation, and how that relates to more recent findings...... of a regulatory effect of the PFC on the emotional control of our actions....

Effects of DBS, premotor rTMS, and levodopa on motor function and silent period in advanced Parkinson's disease

DEFF Research Database (Denmark)

Bäumer, Tobias; Hidding, Ute; Hamel, Wolfgang

2009-01-01

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a widely used and highly effective treatment for patients with advanced Parkinson's disease (PD). Repetitive TMS (rTMS) applied to motor cortical areas has also been shown to improve symptoms in PD and modulate motor cortical...... excitability. Here, we compared clinical and neurophysiological effects of STN stimulation with those of 1 Hz rTMS given to the dorsal premotor cortex (PMd) and those following intake of levodopa in a group of PD patients with advanced disease. Ten PD patients were studied on 2 consecutive days before...... and after surgery. Clinical effects were determined using the UPDRS motor score. Motor thresholds, motor-evoked potential (MEP) amplitudes during slight voluntary contraction, and the cortical silent periods (SP) were measured using TMS. Before surgery effects of levodopa and 1 Hz PMd rTMS and after surgery...

Functional MRI study of cerebral cortical activation during volitional swallowing

International Nuclear Information System (INIS)

Wakasa, Toru; Aiga, Hideki; Yanagi, Yoshinobu; Kawai, Noriko; Sugimoto, Tomosada; Kuboki, Takuo; Kishi, Kanji

2002-01-01

The purpose of this study was to investigate the somatotropic distribution and lateralization of motor and sensory cortical activity during swallowing in healthy adult human subjects using functional MR imaging. Nine healthy right-handed adult volunteers (6 men, 3 women; ages 22-38) were examined. Their cortical activities were evoked by having them swallow, five times, a small bolus of water (3 ml) supplied through a plastic catheter. As a positive control, the subjects performed five repetitions of right-handed grasping tasks. Blood oxygenation level-dependent images were obtained using a 1.5 Tesla MR system (Magnetom Vision, Siemens Germany; repetition time/echo time (TR/TE)=0.96/0.66, flip angle (FA)=90 deg). T1 weighted anatomical images were obtained for the same slices in each subject. Cerebral activity was observed most notably in the primary motor cortex and primary somatosensory cortex, followed by the premotor cortex, anterior cingulate cortex, frontal operculum, and insula. The hand-grasping task activated relatively superior parts of the primary motor and somatosensory cortices. The swallowing task, on the other hand, activated the inferior parts of the pre- and postcentral gyri. The hand-grasping activation of motor and sensory cortices was localized absolutely on the contralateral side, whereas swallowing activated the motor cortex either bilaterally or unilaterally. Swallowing activated the sensory cortex almost always bilaterally. This study suggested that fMRI could be used to identify the specific areas of cortical activation caused by various tasks, and to differentiate the locations of cortical activation between tasks. (author)

Functional MRI study of cerebral cortical activation during volitional swallowing

Energy Technology Data Exchange (ETDEWEB)

Wakasa, Toru; Aiga, Hideki; Yanagi, Yoshinobu; Kawai, Noriko; Sugimoto, Tomosada; Kuboki, Takuo; Kishi, Kanji [Okayama Univ. (Japan). Graduate School of Medicine and Dentistry

2002-12-01

The purpose of this study was to investigate the somatotropic distribution and lateralization of motor and sensory cortical activity during swallowing in healthy adult human subjects using functional MR imaging. Nine healthy right-handed adult volunteers (6 men, 3 women; ages 22-38) were examined. Their cortical activities were evoked by having them swallow, five times, a small bolus of water (3 ml) supplied through a plastic catheter. As a positive control, the subjects performed five repetitions of right-handed grasping tasks. Blood oxygenation level-dependent images were obtained using a 1.5 Tesla MR system (Magnetom Vision, Siemens Germany; repetition time/echo time (TR/TE)=0.96/0.66, flip angle (FA)=90 deg). T1 weighted anatomical images were obtained for the same slices in each subject. Cerebral activity was observed most notably in the primary motor cortex and primary somatosensory cortex, followed by the premotor cortex, anterior cingulate cortex, frontal operculum, and insula. The hand-grasping task activated relatively superior parts of the primary motor and somatosensory cortices. The swallowing task, on the other hand, activated the inferior parts of the pre- and postcentral gyri. The hand-grasping activation of motor and sensory cortices was localized absolutely on the contralateral side, whereas swallowing activated the motor cortex either bilaterally or unilaterally. Swallowing activated the sensory cortex almost always bilaterally. This study suggested that fMRI could be used to identify the specific areas of cortical activation caused by various tasks, and to differentiate the locations of cortical activation between tasks. (author)

The shared neural basis of empathy and facial imitation accuracy.

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Braadbaart, L; de Grauw, H; Perrett, D I; Waiter, G D; Williams, J H G

2014-01-01

Empathy involves experiencing emotion vicariously, and understanding the reasons for those emotions. It may be served partly by a motor simulation function, and therefore share a neural basis with imitation (as opposed to mimicry), as both involve sensorimotor representations of intentions based on perceptions of others' actions. We recently showed a correlation between imitation accuracy and Empathy Quotient (EQ) using a facial imitation task and hypothesised that this relationship would be mediated by the human mirror neuron system. During functional Magnetic Resonance Imaging (fMRI), 20 adults observed novel 'blends' of facial emotional expressions. According to instruction, they either imitated (i.e. matched) the expressions or executed alternative, pre-prescribed mismatched actions as control. Outside the scanner we replicated the association between imitation accuracy and EQ. During fMRI, activity was greater during mismatch compared to imitation, particularly in the bilateral insula. Activity during imitation correlated with EQ in somatosensory cortex, intraparietal sulcus and premotor cortex. Imitation accuracy correlated with activity in insula and areas serving motor control. Overlapping voxels for the accuracy and EQ correlations occurred in premotor cortex. We suggest that both empathy and facial imitation rely on formation of action plans (or a simulation of others' intentions) in the premotor cortex, in connection with representations of emotional expressions based in the somatosensory cortex. In addition, the insula may play a key role in the social regulation of facial expression. © 2013.

Acute pharmacogenetic activation of medial prefrontal cortex ...

Indian Academy of Sciences (India)

Sthitapranjya Pati

2018-01-24

Jan 24, 2018 ... Exclusively Activated by Designer Drugs (DREADDs) have provided novel ... ad libitum access to food and water. ... testing. 2.3 Drug treatment and behavioural tests .... IL cortex (figure 3E, two-way ANOVA: interaction effect,.

Synaptic and functional linkages between spinal premotor interneurons and hand-muscle activity during precision grip

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Tomohiko eTakei

2013-04-01

Full Text Available Grasping is a highly complex movement that requires the coordination of a number of hand joints and muscles. Previous studies showed that spinal premotor interneurons (PreM-INs in the primate cervical spinal cord have divergent synaptic effects on hand motoneurons and that they might contribute to hand-muscle synergies. However, the extent to which these PreM-IN synaptic connections functionally contribute to modulating hand-muscle activity is not clear. In this paper, we explored the contribution of spinal PreM-INs to hand-muscle activation by quantifying the synaptic linkage (SL and functional linkage (FL of the PreM-INs with hand-muscle activities. The activity of 23 PreM-INs was recorded from the cervical spinal cord (C6–T1, with EMG signals measured simultaneously from hand and arm muscles in two macaque monkeys performing a precision grip task. Spike-triggered averages (STAs of rectified EMGs were compiled for 456 neuron–muscle pairs; 63 pairs showed significant post-spike effects (i.e., SL. Conversely, 231 of 456 pairs showed significant cross-correlations between the IN firing rate and rectified EMG (i.e., FL. Importantly, a greater proportion of the neuron–muscle pairs with SL showed FL (43/63 pairs, 68% compared with the pairs without SL (203/393, 52%, and the presence of SL was significantly associated with that of FL. However, a significant number of pairs had SL without FL (SL∩!FL, n = 20 or FL without SL (!SL∩FL, n = 203, and the proportions of these incongruities exceeded the number expected by chance. These results suggested that spinal PreM-INs function to significantly modulate hand-muscle activity during precision grip, but the contribution of other neural structures is also needed to recruit an adequate combination of hand-muscle motoneurons.

Who Can Diagnose Parkinson's Disease First? Role of Pre-motor Symptoms.

Science.gov (United States)

Rodríguez-Violante, Mayela; Zerón-Martínez, Rosalía; Cervantes-Arriaga, Amin; Corona, Teresa

2017-04-01

In 1817, James Parkinson described the disease which bears his name. The disease was defined as a neurological syndrome characterized by tremor, rigidity, and slowness of movements. Almost one hundred years later, degeneration of neurons in the substantia nigra and low levels of dopamine were identified as the putative cause of the disease, thus the disease remained as a pure neurological disorder. In the late 1990s, non-motor symptoms of the disease began to gain interest because of their clinical relevance, as well as for their potential role in broadening the understanding of the pathophysiological mechanisms involved. In the last decade, focus has shifted to the pre-motor symptoms, those non-motor symptoms that present years before the motor onset of the disease. The main premotor symptoms include rapid eye movement sleep behavior disorder, hyposmia, constipation and depression. Subjects with these symptoms usually are not initially seen by a neurologist, and by the time they are consulted neuronal loss in the substantia nigra is over 50%. This review summarizes the overall relevance of non-motor symptoms, their frequency and their pathophysiological implications. Also, the importance of pre-motor symptoms, and the role of specialists other than neurologists in diagnosing subjects with Parkinson's disease is discussed. Two hundred years after the first description of the disease, it is now evident that Parkinson's disease is a systemic disease and a multispecialty team approach is mandatory. Copyright © 2017 IMSS. Published by Elsevier Inc. All rights reserved.

Functional imaging reveals movement preparatory activity in the vegetative state

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Tristan A Bekinschtein

2011-01-01

Full Text Available The Vegetative State (VS is characterized by the absence of awareness of self or the environment and preserved autonomic functions. The diagnosis relies critically on the lack of consistent signs of purposeful behavior in response to external stimulation. Yet, given that patients with disorders of consciousness often exhibit fragmented movement patterns, voluntary actions may go unnoticed. Here we designed a simple motor paradigm that could potentially detect residual conscious awareness in VS patients with mild to severe brain damage by examining the neural correlates of motor preparation in response to verbal commands. Twenty-four patients who met the diagnostic criteria for VS were recruited for this study. Eleven of these patients showing preserved auditory evoked potentials underwent functional magnetic resonance imaging (fMRI to test for basic speech processing. Five of these patients, who showed word related activity, were included in a second fMRI study aimed at detecting functional changes in premotor cortex elicited by specific verbal instructions to move either their left or their right hand. Despite the lack of overt muscle activity, two patients out of five activated the dorsal premotor cortex contralateral to the instructed hand, consistent with movement preparation. Given that movement preparation in response to a motor command is a sign of purposeful behavior, our results are consistent with residual conscious awareness in these patients. We believe that the identification of positive results with fMRI using this simple task, may complement the clinical assessment by helping attain a more precise diagnosis in patients with disorders of consciousness.

Functional imaging of cerebral cortex activation with a 1.5-T MR imaging system

International Nuclear Information System (INIS)

Kim, Jae Hyoung; Chang, Sun Ae; Ha, Choong Kun; Kim, Eun Sang; Kim, Hyung Jin; Chung, Sung Hoon

1995-01-01

Most of recent MR imagings of cerebral cortex activation have been performed by using high field magnet above 2-T or echo-planar imaging technique. We report our experience on imaging of cerebral cortex activation with a widely available standard 1.5-T MR. Series of gradient-echo images (TR/TE/flip angle: 80/60/40 .deg. 64 x 128 matrix) were acquired alternatively during the periods of rest and task in five normal volunteers. Finger movement (n = 10;5 right, 5 left) and flashing photic stimulation (n 1) were used as a motor task and a visual task to activate the motor cortex and visual cortex, respectively. Activation images were obtained by subtracting sum of rest images from that of task images. Changes of signal intensity were analyzed over the periods of rest and task. Activation images were obtained in all cases. Changes of signal intensity between rest and task periods were 6.5-14.6%(mean, 10.5%) in the motor cortex and 4.2% in the visual cortex. Functional imaging of cerebral cortex activation could be performed with a widely available 1.5-T MR. Widespread applications of this technique to basic and clinical neuroscience are expected

Functional imaging of cerebral cortex activation with a 1.5-T MR imaging system

Energy Technology Data Exchange (ETDEWEB)

Kim, Jae Hyoung; Chang, Sun Ae; Ha, Choong Kun; Kim, Eun Sang; Kim, Hyung Jin; Chung, Sung Hoon [Gyeongsang National University, College of Medicine, Jeongju (Korea, Republic of)

1995-07-15

Most of recent MR imagings of cerebral cortex activation have been performed by using high field magnet above 2-T or echo-planar imaging technique. We report our experience on imaging of cerebral cortex activation with a widely available standard 1.5-T MR. Series of gradient-echo images (TR/TE/flip angle: 80/60/40 .deg. 64 x 128 matrix) were acquired alternatively during the periods of rest and task in five normal volunteers. Finger movement (n = 10;5 right, 5 left) and flashing photic stimulation (n 1) were used as a motor task and a visual task to activate the motor cortex and visual cortex, respectively. Activation images were obtained by subtracting sum of rest images from that of task images. Changes of signal intensity were analyzed over the periods of rest and task. Activation images were obtained in all cases. Changes of signal intensity between rest and task periods were 6.5-14.6%(mean, 10.5%) in the motor cortex and 4.2% in the visual cortex. Functional imaging of cerebral cortex activation could be performed with a widely available 1.5-T MR. Widespread applications of this technique to basic and clinical neuroscience are expected.

Ketogenic diet alters dopaminergic activity in the mouse cortex.

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Church, William H; Adams, Ryan E; Wyss, Livia S

2014-06-13

The present study was conducted to determine if the ketogenic diet altered basal levels of monoamine neurotransmitters in mice. The catecholamines dopamine (DA) and norephinephrine (NE) and the indolamine serotonin (5HT) were quantified postmortem in six different brain regions of adult mice fed a ketogenic diet for 3 weeks. The dopamine metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) and the serotonin metabolite 5-hydroxyindole acetic acid (5HIAA) were also measured. Tissue punches were collected bilaterally from the motor cortex, somatosensory cortex, nucleus accumbens, anterior caudate-putamen, posterior caudate-putamen and the midbrain. Dopaminergic activity, as measured by the dopamine metabolites to dopamine content ratio - ([DOPAC]+[HVA])/[DA] - was significantly increased in the motor and somatosensory cortex regions of mice fed the ketogenic diet when compared to those same areas in brains of mice fed a normal diet. These results indicate that the ketogenic diet alters the activity of the meso-cortical dopaminergic system, which may contribute to the diet's therapeutic effect in reducing epileptic seizure activity. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

The cortical activation pattern by a rehabilitation robotic hand : A functional NIRS study

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Pyung Hun eChang

2014-02-01

Full Text Available Introduction: Clarification of the relationship between external stimuli and brain response has been an important topic in neuroscience and brain rehabilitation. In the current study, using functional near infrared spectroscopy (fNIRS, we attempted to investigate cortical activation patterns generated during execution of a rehabilitation robotic hand. Methods: Ten normal subjects were recruited for this study. Passive movements of the right fingers were performed using a rehabilitation robotic hand at a frequency of 0.5 Hz. We measured values of oxy-hemoglobin(HbO, deoxy-hemoglobin(HbR and total-hemoglobin(HbT in five regions of interest: the primary sensory-motor cortex (SM1, hand somatotopy of the contralateral SM1, supplementary motor area (SMA, premotor cortex (PMC, and prefrontal cortex (PFC. Results: HbO and HbT values indicated significant activation in the left SM1, left SMA, left PMC, and left PFC during execution of the rehabilitation robotic hand(uncorrected, pConclusions: Our results appear to indicate that execution of the rehabilitation robotic hand could induce cortical activation.

Blood oxygenation level dependent functional MRI study on the changes of motor cortex in patients with amyotrophic lateral sclerosis

International Nuclear Information System (INIS)

Han Jing; Ma Lin; Lou Xin; Yu Shengyuan; Li Dejun

2008-01-01

Objective: To study the changes of motor cortex in patients with amyotrophic lateral sclerosis (ALS) while executing sequential finger tapping movement by using blood oxygenation level dependent (BOLD) functional MRI. Methods: Fifteen patients with definite or probable ALS and 15 age and gender matched normal controls were enrolled in the BOLD study, and all the subjects were right-handed with no other diseases or any recent medication history. A 3.0 T MR scanner' was employed and gradient echo EPI (GRE-EPI)sequence was used to acquire the functional images. Subjects executed sequential finger tapping movement at a frequency of 1-2 Hz during a block design task. fMRI data were analyzed by using statistical parametric mapping (SPM) 2. Volume of activated brain areas was compared with the use of a Student's t-test. Results: Bilateral primary sensorimotor cortex (PSM), bilateral posterior aspect of premotor area (PA), bilateral supplementary motor area (SMA), contralateral inferior lateral premotor area (ILPA), bilateral parietal region (PAR), and ipsilateral cerebellum showed activation in both ALS patients and normal controls when executing the same motor task. The activation areas in bilateral PSM and bilateral posterior aspect of PA ( right hand ipsilateral activation: ALS (924.5±141.1) mm 3 , control (829.9± 98.4) mm 3 , P=0.05; right hand contralateral activation: ALS (9143.8±702.8) mm 3 , control (8638.8±506.4) mm 3 P 3 , control (902.5±3 184.2)mm , P 3 , control (5934.6±616.4) mm 3 , P 3 , control (4710.7±416.3) mm 3 , P 3 , control (3688.9±672.3) mm 3 , P 3 , control (254.3±84.4) mm 3 , P 3 , control (1689.0±719.6) mm 3 , P<0.05) were significantly larger in ALS patients than in normal controls. Extra activation areas including ipsilateral ILPA, contralateral cerebellum and bilateral posterior limb of internal capsule were only detected in ALS patients. Conclusions: Similar activation areas were seen in both groups while executing the same motor

Illusory sensation of movement induced by repetitive transcranial magnetic stimulation

DEFF Research Database (Denmark)

Christensen, Mark Schram; Lundbye-Jensen, Jesper; Grey, Michael James

2010-01-01

Human movement sense relies on both somatosensory feedback and on knowledge of the motor commands used to produce the movement. We have induced a movement illusion using repetitive transcranial magnetic stimulation over primary motor cortex and dorsal premotor cortex in the absence of limb movement...... and its associated somatosensory feedback. Afferent and efferent neural signalling was abolished in the arm with ischemic nerve block, and in the leg with spinal nerve block. Movement sensation was assessed following trains of high-frequency repetitive transcranial magnetic stimulation applied over...... premotor cortex stimulation was less affected by sensory and motor deprivation than was primary motor cortex stimulation. We propose that repetitive transcranial magnetic stimulation over dorsal premotor cortex produces a corollary discharge that is perceived as movement....

High-intensity erotic visual stimuli de-activate the primary visual cortex in women.

Science.gov (United States)

Huynh, Hieu K; Beers, Caroline; Willemsen, Antoon; Lont, Erna; Laan, Ellen; Dierckx, Rudi; Jansen, Monique; Sand, Michael; Weijmar Schultz, Willibrord; Holstege, Gert

2012-06-01

The primary visual cortex, Brodmann's area (BA 17), plays a vital role in basic survival mechanisms in humans. In most neuro-imaging studies in which the volunteers have to watch pictures or movies, the primary visual cortex is similarly activated independent of the content of the pictures or movies. However, in case the volunteers perform demanding non-visual tasks, the primary visual cortex becomes de-activated, although the amount of incoming visual sensory information is the same. Do low- and high-intensity erotic movies, compared to neutral movies, produce similar de-activation of the primary visual cortex? Brain activation/de-activation was studied by Positron Emission Tomography scanning of the brains of 12 healthy heterosexual premenopausal women, aged 18-47, who watched neutral, low- and high-intensity erotic film segments. We measured differences in regional cerebral blood flow (rCBF) in the primary visual cortex during watching neutral, low-intensity erotic, and high-intensity erotic film segments. Watching high-intensity erotic, but not low-intensity erotic movies, compared to neutral movies resulted in strong de-activation of the primary (BA 17) and adjoining parts of the secondary visual cortex. The strong de-activation during watching high-intensity erotic film might represent compensation for the increased blood supply in the brain regions involved in sexual arousal, also because high-intensity erotic movies do not require precise scanning of the visual field, because the impact is clear to the observer. © 2012 International Society for Sexual Medicine.

Stereoscopically Observing Manipulative Actions.

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Ferri, S; Pauwels, K; Rizzolatti, G; Orban, G A

2016-08-01

The purpose of this study was to investigate the contribution of stereopsis to the processing of observed manipulative actions. To this end, we first combined the factors "stimulus type" (action, static control, and dynamic control), "stereopsis" (present, absent) and "viewpoint" (frontal, lateral) into a single design. Four sites in premotor, retro-insular (2) and parietal cortex operated specifically when actions were viewed stereoscopically and frontally. A second experiment clarified that the stereo-action-specific regions were driven by actions moving out of the frontoparallel plane, an effect amplified by frontal viewing in premotor cortex. Analysis of single voxels and their discriminatory power showed that the representation of action in the stereo-action-specific areas was more accurate when stereopsis was active. Further analyses showed that the 4 stereo-action-specific sites form a closed network converging onto the premotor node, which connects to parietal and occipitotemporal regions outside the network. Several of the specific sites are known to process vestibular signals, suggesting that the network combines observed actions in peripersonal space with gravitational signals. These findings have wider implications for the function of premotor cortex and the role of stereopsis in human behavior. © The Author 2016. Published by Oxford University Press.

Functional activation of the infant cortex during object processing.

Science.gov (United States)

Wilcox, Teresa; Stubbs, Jessica; Hirshkowitz, Amy; Boas, David A

2012-09-01

A great deal is known about the functional organization of the neural structures that mediate visual object processing in the adult observer. These findings have contributed significantly to our conceptual models of object recognition and identification and provided unique insight into the nature of object representations extracted from visual input. In contrast, little is known about the neural basis of object processing in the infant. The current research used near-infrared spectroscopy (NIRS) as a neuroimaging tool to investigate functional activation of the infant cortex during an object processing task that has been used extensively with infants. The neuroimaging data revealed that the infant cortex is functionally specialized for object processing (i.e., individuation-by-feature) early in the first year but that patterns of activation also change between 3 and 12 months. These changes may reflect functional reorganization of the immature cortex or age-related differences in the cognitive processes engaged during the task. Copyright © 2012 Elsevier Inc. All rights reserved.

Spatial diversity of spontaneous activity in the cortex

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Andrew Yong-Yi Tan

2015-09-01

Full Text Available The neocortex is a layered sheet across which a basic organization is thought to widely apply. The variety of spontaneous activity patterns is similar throughout the cortex, consistent with the notion of a basic cortical organization. However, the basic organization is only an outline which needs adjustments and additions to account for the structural and functional diversity across cortical layers and areas. Such diversity suggests that spontaneous activity is spatially diverse in any particular behavioral state. Accordingly, this review summarizes the laminar and areal diversity in cortical activity during fixation and slow oscillations, and the effects of attention, anesthesia and plasticity on the cortical distribution of spontaneous activity. Among questions that remain open, characterizing the spatial diversity in spontaneous membrane potential may help elucidate how differences in circuitry among cortical regions supports their varied functions. More work is also needed to understand whether cortical spontaneous activity not only reflects cortical circuitry, but also contributes to determining the outcome of plasticity, so that it is itself a factor shaping the functional diversity of the cortex.

Insular cortex activity and the evocation of laughter.

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Wattendorf, Elise; Westermann, Birgit; Lotze, Martin; Fiedler, Klaus; Celio, Marco R

2016-06-01

The insular cortex is fundamentally involved in the processing of interoceptive information. It has been postulated that the integrative monitoring of the bodily responses to environmental stimuli is crucial for the recognition and experience of emotions. Because emotional arousal is known to be closely coupled to functions of the anterior insula, we suspected laughter to be associated primarily with neuronal activity in this region. An anatomically constrained re-analysis of our imaging data pertaining to ticklish laughter, to inhibited ticklish laughter, and to voluntary laughter revealed regional differences in the levels of neuronal activity in the posterior and mid-/anterior portions of the insula. Ticklish laughter was associated specifically with right ventral anterior insular activity, which was not detected under the other two conditions. Hence, apparently, only laughter that is evoked as an emotional response bears the signature of autonomic arousal in the insular cortex. © 2015 Wiley Periodicals, Inc.

Effects of SR141716A on Cognitive and Depression-Related Behavior in an Animal Model of Premotor Parkinson's Disease

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M. T. Tadaiesky

2010-01-01

Full Text Available A previous study from our laboratory revealed that moderate nigral dopaminergic degeneration caused emotional and cognitive deficits in rats, paralleling early signs of Parkinson's disease. Recent evidence suggests that the blockade of cannabinoid CB1 receptors might be beneficial to alleviate motor inhibition typical of Parkinson's disease. Here, we investigated whether antagonism of CB1 receptors would improve emotional and cognitive deficits in a rat model of premotor Parkinson's disease. Depression-like behavior and cognition were assessed with the forced swim test and the social recognition test, respectively. Confirming our previous study, rats injected with 6-hydroxydopamine in striatum presented emotional and cognitive alterations which were improved by acute injection of SR141716A. HPLC analysis of monoamine levels demonstrated alterations in the striatum and prefrontal cortex after SR141716A injection. These findings suggest a role for CB1 receptors in the early symptoms caused by degeneration of dopaminergic neurons in the striatum, as observed in Parkinson's disease.

The lateralization of motor cortex activation to action words

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Olaf eHauk

2011-11-01

Full Text Available What determines the laterality of activation in motor cortex for words whose meaning is related to bodily actions? It has been suggested that the neuronal representation of the meaning of action-words is shaped by individual experience. However, core language functions are left-lateralized in the majority of both right- and left-handers. It is still an open question to what degree connections between left-hemispheric core language areas and right-hemispheric motor areas can play a role in semantics. We investigated laterality of brain activation using fMRI in right- and left-handed participants in response to visually presented hand-related action-words, namely uni- and bi-manual actions (such as "throw" and "clap". These stimulus groups were matched with respect to general (hand-action-relatedness, but differed with respect to whether they are usually performed with the dominant hand or both hands. We may expect generally more left-hemispheric motor-cortex activation for hand-related words in both handedness groups, with possibly more bilateral activation for bimanual words as well as left-handers. In our study, both participant groups activated motor cortex bilaterally for bi-manual words. Interestingly, both groups also showed a left-lateralized activation pattern to uni-manual words. We argue that this reflects the effect of left-hemispheric language dominance on the formation of semantic brain circuits on the basis of Hebbian correlation learning.

The cortical activation pattern by a rehabilitation robotic hand: a functional NIRS study.

Science.gov (United States)

Chang, Pyung-Hun; Lee, Seung-Hee; Gu, Gwang Min; Lee, Seung-Hyun; Jin, Sang-Hyun; Yeo, Sang Seok; Seo, Jeong Pyo; Jang, Sung Ho

2014-01-01

Clarification of the relationship between external stimuli and brain response has been an important topic in neuroscience and brain rehabilitation. In the current study, using functional near infrared spectroscopy (fNIRS), we attempted to investigate cortical activation patterns generated during execution of a rehabilitation robotic hand. Ten normal subjects were recruited for this study. Passive movements of the right fingers were performed using a rehabilitation robotic hand at a frequency of 0.5 Hz. We measured values of oxy-hemoglobin (HbO), deoxy-hemoglobin (HbR) and total-hemoglobin (HbT) in five regions of interest: the primary sensory-motor cortex (SM1), hand somatotopy of the contralateral SM1, supplementary motor area (SMA), premotor cortex (PMC), and prefrontal cortex (PFC). HbO and HbT values indicated significant activation in the left SM1, left SMA, left PMC, and left PFC during execution of the rehabilitation robotic hand (uncorrected, p < 0.01). By contrast, HbR value indicated significant activation only in the hand somatotopic area of the left SM1 (uncorrected, p < 0.01). Our results appear to indicate that execution of the rehabilitation robotic hand could induce cortical activation.

Premotor Diagnosis of Parkinson's Disease

Institute of Scientific and Technical Information of China (English)

Heinz Reichmann

2017-01-01

Typical Parkinsonian symptoms consist of bradykinesia plus rigidity and/or resting tremor.Some time later postural instability occurs.Pre-motor symptoms such as hyposmia,constipation,REM sleep behavior disorder and depression may antecede these motor symptoms for years.It would be ideal,if we had a biomarker which would allow to predict who with one or two of these pre-motor symptoms will develop the movement disorder Parkinson's disease (PD).Thus,it is interesting to learn that biopsies of the submandibular gland or colon biopsies may be a means to predict PD,if there is a high amout of abnormally folded alpha-synuclein and phosphorylated alpha-synuclein.This would be of relevance if we would have available means to stop the propagation of abnormal alpha-synuclein which is otherwise one of the reasons of this spreading disease PD.

Functions of delay-period activity in the prefrontal cortex and mnemonic scotomas revisited

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Shintaro eFunahashi

2015-02-01

Full Text Available Working memory is one of key concepts to understand functions of the prefrontal cortex. Delay-period activity is an important neural correlate to understand the role of working memory in prefrontal functions. The importance of delay-period activity is that this activity can encode not only visuospatial information but also a variety of information including non-spatial visual features, auditory and tactile stimuli, task rules, expected reward, and numerical quantity. This activity also participates in a variety of information processing including sensory-to-motor information transformation. These mnemonic features of delay-period activity enable to perform various important operations that the prefrontal cortex participates in, such as executive controls, and therefore, support the notion that working memory is an important function to understand prefrontal functions. On the other hand, although experiments using manual versions of the delayed-response task had revealed many important findings, an oculomotor version of this task enabled us to use multiple cue positions, exclude postural orientation during the delay period, and further prove the importance of mnemonic functions of the prefrontal cortex. In addition, monkeys with unilateral lesions exhibited specific impairment only in the performance of memory-guided saccades directed toward visual cues in the visual field contralateral to the lesioned hemisphere. This result indicates that memories for visuospatial coordinates in each hemifield are processed primarily in the contralateral prefrontal cortex. This result further strengthened the idea of mnemonic functions of the prefrontal cortex. Thus, the mnemonic functions of the prefrontal cortex and delay-period activity may not need to be reconsidered, but should be emphasized.

When vision guides movement: a functional imaging study of the monkey brain.

Science.gov (United States)

Gregoriou, Georgia G; Savaki, Helen E

2003-07-01

Goal-directed reaching requires a precise neural representation of the arm position and the target location. Parietal and frontal cortical areas rely on visual, somatosensory, and motor signals to guide the reaching arm to the desired position in space. To dissociate the regions processing these signals, we applied the quantitative [(14)C]-deoxyglucose method on monkeys reaching either in the light or in the dark. Nonvisual (somatosensory and memory-related) guidance of the arm, during reaching in the dark, induced activation of discrete regions in the parietal, premotor, and motor cortices. These included the dorsal part of the medial bank of the intraparietal sulcus, the ventral premotor area F4, the dorsal premotor area F2 below the superior precentral dimple, and the primary somatosensory and motor cortices. Additional parietal and premotor regions comprising the ventral intraparietal cortex, ventral premotor area F5, and the ventral part of dorsal premotor area F2 were activated by visual guidance of the arm during reaching in the light. This study provides evidence that different regions of the parieto-premotor circuit process the visual, somatosensory, and motor-memory-related signals which guide the moving arm.

Intracortical Microstimulation (ICMS) Activates Motor Cortex Layer 5 Pyramidal Neurons Mainly Transsynaptically.

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Hussin, Ahmed T; Boychuk, Jeffery A; Brown, Andrew R; Pittman, Quentin J; Teskey, G Campbell

2015-01-01

Intracortical microstimulation (ICMS) is a technique used for a number of purposes including the derivation of cortical movement representations (motor maps). Its application can activate the output layer 5 of motor cortex and can result in the elicitation of body movements depending upon the stimulus parameters used. The extent to which pyramidal tract projection neurons of the motor cortex are activated transsynaptically or directly by ICMS remains an open question. Given this uncertainty in the mode of activation, we used a preparation that combined patch clamp whole-cell recordings from single layer 5 pyramidal neurons and extracellular ICMS in slices of motor cortex as well as a standard in vivo mapping technique to ask how ICMS activated motor cortex pyramidal neurons. We measured changes in synaptic spike threshold and spiking rate to ICMS in vitro and movement threshold in vivo in the presence or absence of specific pharmacological blockers of glutamatergic (AMPA, NMDA and Kainate) receptors and GABAA receptors. With major excitatory and inhibitory synaptic transmission blocked (with DNQX, APV and bicuculline methiodide), we observed a significant increase in the ICMS current intensity required to elicit a movement in vivo as well as to the first spike and an 85% reduction in spiking responses in vitro. Subsets of neurons were still responsive after the synaptic block, especially at higher current intensities, suggesting a modest direct activation. Taken together our data indicate a mainly synaptic mode of activation to ICMS in layer 5 of rat motor cortex. Copyright © 2015 Elsevier Inc. All rights reserved.

False memory for context and true memory for context similarly activate the parahippocampal cortex.

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Karanian, Jessica M; Slotnick, Scott D

2017-06-01

The role of the parahippocampal cortex is currently a topic of debate. One view posits that the parahippocampal cortex specifically processes spatial layouts and sensory details (i.e., the visual-spatial processing view). In contrast, the other view posits that the parahippocampal cortex more generally processes spatial and non-spatial contexts (i.e., the general contextual processing view). A large number of studies have found that true memories activate the parahippocampal cortex to a greater degree than false memories, which would appear to support the visual-spatial processing view as true memories are typically associated with greater visual-spatial detail than false memories. However, in previous studies, contextual details were also greater for true memories than false memories. Thus, such differential activity in the parahippocampal cortex may have reflected differences in contextual processing, which would challenge the visual-spatial processing view. In the present functional magnetic resonance imaging (fMRI) study, we employed a source memory paradigm to investigate the functional role of the parahippocampal cortex during true memory and false memory for contextual information to distinguish between the visual-spatial processing view and the general contextual processing view. During encoding, abstract shapes were presented to the left or right of fixation. During retrieval, old shapes were presented at fixation and participants indicated whether each shape was previously on the "left" or "right" followed by an "unsure", "sure", or "very sure" confidence rating. The conjunction of confident true memories for context and confident false memories for context produced activity in the parahippocampal cortex, which indicates that this region is associated with contextual processing. Furthermore, the direct contrast of true memory and false memory produced activity in the visual cortex but did not produce activity in the parahippocampal cortex. The present

Tactile interactions activate mirror system regions in the human brain.

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McKyton, Ayelet

2011-12-07

Communicating with others is essential for the development of a society. Although types of communications, such as language and visual gestures, were thoroughly investigated in the past, little research has been done to investigate interactions through touch. To study this we used functional magnetic resonance imaging. Twelve participants were scanned with their eyes covered while stroking four kinds of items, representing different somatosensory stimuli: a human hand, a realistic rubber hand, an object, and a simple texture. Although the human and the rubber hands had the same overall shape, in three regions there was significantly more blood oxygen level dependent activation when touching the real hand: the anterior medial prefrontal cortex, the ventral premotor cortex, and the posterior superior temporal cortex. The last two regions are part of the mirror network and are known to be activated through visual interactions such as gestures. Interestingly, in this study, these areas were activated through a somatosensory interaction. A control experiment was performed to eliminate confounds of temperature, texture, and imagery, suggesting that the activation in these areas was correlated with the touch of a human hand. These results reveal the neuronal network working behind human tactile interactions, and highlight the participation of the mirror system in such functions.

The neural correlates of emotional prosody comprehension: disentangling simple from complex emotion.

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Lucy Alba-Ferrara

Full Text Available BACKGROUND: Emotional prosody comprehension (EPC, the ability to interpret another person's feelings by listening to their tone of voice, is crucial for effective social communication. Previous studies assessing the neural correlates of EPC have found inconsistent results, particularly regarding the involvement of the medial prefrontal cortex (mPFC. It remained unclear whether the involvement of the mPFC is linked to an increased demand in socio-cognitive components of EPC such as mental state attribution and if basic perceptual processing of EPC can be performed without the contribution of this region. METHODS: fMRI was used to delineate neural activity during the perception of prosodic stimuli conveying simple and complex emotion. Emotional trials in general, as compared to neutral ones, activated a network comprising temporal and lateral frontal brain regions, while complex emotion trials specifically showed an additional involvement of the mPFC, premotor cortex, frontal operculum and left insula. CONCLUSION: These results indicate that the mPFC and premotor areas might be associated, but are not crucial to EPC. However, the mPFC supports socio-cognitive skills necessary to interpret complex emotion such as inferring mental states. Additionally, the premotor cortex involvement may reflect the participation of the mirror neuron system for prosody processing particularly of complex emotion.

Nonlinear responses within the medial prefrontal cortex reveal when specific implicit information influences economic decision making.

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Deppe, Michael; Schwindt, Wolfram; Kugel, Harald; Plassmann, Hilke; Kenning, Peter

2005-04-01

The authors used functional magnetic resonance imaging (fMRI) to investigate how individual economic decisions are influenced by implicit memory contributions. Twenty-two participants were asked to make binary decisions between different brands of sensorily nearly undistinguishable consumer goods. Changes of brain activity comparing decisions in the presence or absence of a specific target brand were detected by fMRI. Only when the tar get brand was the participant's favorite one did the authors find reduced activation in the dorsolateral prefrontal, posterior parietal, and occipital cortices and the left premotor area (Brodmann areas [BA] 9, 46, 7/19, and 6). Simultaneously, activity was increased in the inferior precuneus and posterior cingulate (BA 7), right superior frontal gyrus (BA 10), right supramarginal gyrus (BA 40), and, most pronounced, in the ventromedial prefrontal cortex (BA 10). For products mainly distinguishable by brand information, the authors revealed a nonlinear winner-take-all effect for a participant's favorite brand characterized, on one hand, by reduced activation in brain areas associated with working memory and reasoning and, on the other hand, increased activation in areas involved in processing of emotions and self-reflections during decision making.

Abnormal activation of the primary somatosensory cortex in spasmodic dysphonia: an fMRI study.

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Simonyan, Kristina; Ludlow, Christy L

2010-11-01

Spasmodic dysphonia (SD) is a task-specific focal dystonia of unknown pathophysiology, characterized by involuntary spasms in the laryngeal muscles during speaking. Our aim was to identify symptom-specific functional brain activation abnormalities in adductor spasmodic dysphonia (ADSD) and abductor spasmodic dysphonia (ABSD). Both SD groups showed increased activation extent in the primary sensorimotor cortex, insula, and superior temporal gyrus during symptomatic and asymptomatic tasks and decreased activation extent in the basal ganglia, thalamus, and cerebellum during asymptomatic tasks. Increased activation intensity in SD patients was found only in the primary somatosensory cortex during symptomatic voice production, which showed a tendency for correlation with ADSD symptoms. Both SD groups had lower correlation of activation intensities between the primary motor and sensory cortices and additional correlations between the basal ganglia, thalamus, and cerebellum during symptomatic and asymptomatic tasks. Compared with ADSD patients, ABSD patients had larger activation extent in the primary sensorimotor cortex and ventral thalamus during symptomatic task and in the inferior temporal cortex and cerebellum during symptomatic and asymptomatic voice production. The primary somatosensory cortex shows consistent abnormalities in activation extent, intensity, correlation with other brain regions, and symptom severity in SD patients and, therefore, may be involved in the pathophysiology of SD.

Functionally Specific Oscillatory Activity Correlates between Visual and Auditory Cortex in the Blind

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Schepers, Inga M.; Hipp, Joerg F.; Schneider, Till R.; Roder, Brigitte; Engel, Andreas K.

2012-01-01

Many studies have shown that the visual cortex of blind humans is activated in non-visual tasks. However, the electrophysiological signals underlying this cross-modal plasticity are largely unknown. Here, we characterize the neuronal population activity in the visual and auditory cortex of congenitally blind humans and sighted controls in a…

A reliability study on brain activation during active and passive arm movements supported by an MRI-compatible robot.

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Estévez, Natalia; Yu, Ningbo; Brügger, Mike; Villiger, Michael; Hepp-Reymond, Marie-Claude; Riener, Robert; Kollias, Spyros

2014-11-01

In neurorehabilitation, longitudinal assessment of arm movement related brain function in patients with motor disability is challenging due to variability in task performance. MRI-compatible robots monitor and control task performance, yielding more reliable evaluation of brain function over time. The main goals of the present study were first to define the brain network activated while performing active and passive elbow movements with an MRI-compatible arm robot (MaRIA) in healthy subjects, and second to test the reproducibility of this activation over time. For the fMRI analysis two models were compared. In model 1 movement onset and duration were included, whereas in model 2 force and range of motion were added to the analysis. Reliability of brain activation was tested with several statistical approaches applied on individual and group activation maps and on summary statistics. The activated network included mainly the primary motor cortex, primary and secondary somatosensory cortex, superior and inferior parietal cortex, medial and lateral premotor regions, and subcortical structures. Reliability analyses revealed robust activation for active movements with both fMRI models and all the statistical methods used. Imposed passive movements also elicited mainly robust brain activation for individual and group activation maps, and reliability was improved by including additional force and range of motion using model 2. These findings demonstrate that the use of robotic devices, such as MaRIA, can be useful to reliably assess arm movement related brain activation in longitudinal studies and may contribute in studies evaluating therapies and brain plasticity following injury in the nervous system.

Correlations decrease with propagation of spiking activity in the mouse barrel cortex

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Gayathri Nattar Ranganathan

2011-05-01

Full Text Available Propagation of suprathreshold spiking activity through neuronal populations is important for the function of the central nervous system. Neural correlations have an impact on cortical function particularly on the signaling of information and propagation of spiking activity. Therefore we measured the change in correlations as suprathreshold spiking activity propagated between recurrent neuronal networks of the mammalian cerebral cortex. Using optical methods we recorded spiking activity from large samples of neurons from two neural populations simultaneously. The results indicate that correlations decreased as spiking activity propagated from layer 4 to layer 2/3 in the rodent barrel cortex.

Structural remodeling of the heart and its premotor cardioinhibitory vagal neurons following T(5) spinal cord transection.

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Lujan, Heidi L; Janbaih, Hussein; DiCarlo, Stephen E

2014-05-01

Midthoracic spinal cord injury (SCI) is associated with enhanced cardiac sympathetic activity and reduced cardiac parasympathetic activity. The enhanced cardiac sympathetic activity is associated with sympathetic structural plasticity within the stellate ganglia, spinal cord segments T1-T4, and heart. However, changes to cardiac parasympathetic centers rostral to an experimental SCI are relatively unknown. Importantly, reduced vagal activity is a predictor of high mortality. Furthermore, this autonomic dysregulation promotes progressive left ventricular (LV) structural remodeling. Accordingly, we hypothesized that midthoracic spinal cord injury is associated with structural plasticity in premotor (preganglionic parasympathetic neurons) cardioinhibitory vagal neurons located within the nucleus ambiguus as well as LV structural remodeling. To test this hypothesis, dendritic arborization and morphology (cholera toxin B immunohistochemistry and Sholl analysis) of cardiac projecting premotor cardioinhibitory vagal neurons located within the nucleus ambiguus were determined in intact (sham transected) and thoracic level 5 transected (T5X) rats. In addition, LV chamber size, wall thickness, and collagen content (Masson trichrome stain and structural analysis) were determined. Midthoracic SCI was associated with structural changes within the nucleus ambiguus and heart. Specifically, following T5 spinal cord transection, there was a significant increase in cardiac parasympathetic preganglionic neuron dendritic arborization, soma area, maximum dendritic length, and number of intersections/animal. This parasympathetic structural remodeling was associated with a profound LV structural remodeling. Specifically, T5 spinal cord transection increased LV chamber area, reduced LV wall thickness, and increased collagen content. Accordingly, results document a dynamic interaction between the heart and its parasympathetic innervation.

A Network Model of Observation and Imitation of Speech

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Mashal, Nira; Solodkin, Ana; Dick, Anthony Steven; Chen, E. Elinor; Small, Steven L.

2012-01-01

Much evidence has now accumulated demonstrating and quantifying the extent of shared regional brain activation for observation and execution of speech. However, the nature of the actual networks that implement these functions, i.e., both the brain regions and the connections among them, and the similarities and differences across these networks has not been elucidated. The current study aims to characterize formally a network for observation and imitation of syllables in the healthy adult brain and to compare their structure and effective connectivity. Eleven healthy participants observed or imitated audiovisual syllables spoken by a human actor. We constructed four structural equation models to characterize the networks for observation and imitation in each of the two hemispheres. Our results show that the network models for observation and imitation comprise the same essential structure but differ in important ways from each other (in both hemispheres) based on connectivity. In particular, our results show that the connections from posterior superior temporal gyrus and sulcus to ventral premotor, ventral premotor to dorsal premotor, and dorsal premotor to primary motor cortex in the left hemisphere are stronger during imitation than during observation. The first two connections are implicated in a putative dorsal stream of speech perception, thought to involve translating auditory speech signals into motor representations. Thus, the current results suggest that flow of information during imitation, starting at the posterior superior temporal cortex and ending in the motor cortex, enhances input to the motor cortex in the service of speech execution. PMID:22470360

The effect of tumour type and distance on activation in the motor cortex

International Nuclear Information System (INIS)

Liu, Wen-Ching; Feldman, Susan C.; Zimmerman, Aphrodite; Sinensky, Rebecca; Rao, Satyaveni; Schulder, Michael; Kalnin, Andrew J.; Holodny, Andrei I.

2005-01-01

Functional MRI has been widely used to identify the eloquent cortex in neurosurgical/radiosurgical planning and treatment of CNS neoplasms and malformations. In this study we examined the effect of CNS tumours on the blood oxygenation level-dependent (BOLD) activation maps in the primary and supplementary motor cortex. A total of 33 tumour patients and five healthy right-handed adults were enrolled in the study. Patients were divided into four groups based on tumour type and distance from primary motor cortex: (1) intra-axial, near, (2) extra-axial, near, (3) intra-axial, far and (4) extra-axial, far. The intra-axial groups consisted of patients with astrocytomas, glioblastomas and metastatic tumours of mixed histology; all the extra-axial tumours were meningiomas. The motor task was a bilateral, self-paced, finger-tapping paradigm. Anatomical and functional data were acquired with a 1.5 T GE Echospeed scanner. Maps of the motor areas were derived from the BOLD images, using SPM99 software. For each subject we first determined the activation volume in the primary motor area and the supplementary motor area (SMA) and then calculated the percentage difference between the hemispheres. Two factors influenced the activation volumes: tumour type (P<0.04) and distance from the eloquent cortex (P<0.06). Patients in group 1 (intra-axial, near) had the smallest activation area in the primary motor cortex, the greatest percentage difference in the activation volume between the hemispheres, and the largest activation volume in the SMA. Patients in group 4 (extra-axial, far) had the largest activation volume in the primary motor cortex, the least percentage difference in volume between the hemispheres, and the smallest activation volume in the SMA. There was no significant change in the volume of the SMA in any group, compared with controls, suggesting that, although there is a gradual decrease in SMA volume with distance from the primary motor area, the effect on motor

Premotor and non-motor features of Parkinson’s disease

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Goldman, Jennifer G.; Postuma, Ron

2014-01-01

Purpose of review This review highlights recent advances in premotor and non-motor features in Parkinson’s disease, focusing on these issues in the context of prodromal and early stage Parkinson’s disease. Recent findings While Parkinson’s disease patients experience a wide range of non-motor symptoms throughout the disease course, studies demonstrate that non-motor features are not solely a late manifestation. Indeed, disturbances of smell, sleep, mood, and gastrointestinal function may herald Parkinson’s disease or related synucleinopathies and precede these neurodegenerative conditions by 5 or more years. In addition, other non-motor symptoms such as cognitive impairment are now recognized in incident or de novo Parkinson’s disease cohorts. Many of these non-motor features reflect disturbances in non-dopaminergic systems and early involvement of peripheral and central nervous systems including olfactory, enteric, and brainstem neurons as in Braak’s proposed pathological staging of Parkinson’s disease. Current research focuses on identifying potential biomarkers that may detect persons at risk for Parkinson’s disease and permit early intervention with neuroprotective or disease-modifying therapeutics. Summary Recent studies provide new insights on the frequency, pathophysiology, and importance of non-motor features in Parkinson’s disease as well as the recognition that these non-motor symptoms occur in premotor, early, and later phases of Parkinson’s disease. PMID:24978368

Psychosocial risk factors, pre-motor symptoms and first-time hospitalization with Parkinson's disease

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Clark, Alice Jessie; Ritz, B; Prescott, E

2013-01-01

), as well as to identify potential pre-motor symptoms for PD in a large prospective cohort study. METHODS: In 1991-1993, a total of 9955 women and men free of PD from the Copenhagen City Heart Study were asked about major life events, economic hardship, social network, impaired sleep and vital exhaustion...... social network in the current study. CONCLUSIONS: Overall, the hypothesis that psychosocial risk factors affect the risk of PD is not supported. The results, however, suggest that vital exhaustion may be a pre-motor marker of the neurodegenerative process eventually leading to motor symptoms and clinical......BACKGROUND AND PURPOSE: Experimental studies support a link between stress and development of parkinsonian symptoms, but prospective population studies are lacking. The aim of the current study is to determine the effects of several psychosocial factors on the risk of Parkinson's disease (PD...

The Neural Basis of Typewriting: A Functional MRI Study.

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Higashiyama, Yuichi; Takeda, Katsuhiko; Someya, Yoshiaki; Kuroiwa, Yoshiyuki; Tanaka, Fumiaki

2015-01-01

To investigate the neural substrate of typewriting Japanese words and to detect the difference between the neural substrate of typewriting and handwriting, we conducted a functional magnetic resonance imaging (fMRI) study in 16 healthy volunteers. All subjects were skillful touch typists and performed five tasks: a typing task, a writing task, a reading task, and two control tasks. Three brain regions were activated during both the typing and the writing tasks: the left superior parietal lobule, the left supramarginal gyrus, and the left premotor cortex close to Exner's area. Although typing and writing involved common brain regions, direct comparison between the typing and the writing task revealed greater left posteromedial intraparietal cortex activation in the typing task. In addition, activity in the left premotor cortex was more rostral in the typing task than in the writing task. These findings suggest that, although the brain circuits involved in Japanese typewriting are almost the same as those involved in handwriting, there are brain regions that are specific for typewriting.

The Neural Basis of Typewriting: A Functional MRI Study.

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Yuichi Higashiyama

Full Text Available To investigate the neural substrate of typewriting Japanese words and to detect the difference between the neural substrate of typewriting and handwriting, we conducted a functional magnetic resonance imaging (fMRI study in 16 healthy volunteers. All subjects were skillful touch typists and performed five tasks: a typing task, a writing task, a reading task, and two control tasks. Three brain regions were activated during both the typing and the writing tasks: the left superior parietal lobule, the left supramarginal gyrus, and the left premotor cortex close to Exner's area. Although typing and writing involved common brain regions, direct comparison between the typing and the writing task revealed greater left posteromedial intraparietal cortex activation in the typing task. In addition, activity in the left premotor cortex was more rostral in the typing task than in the writing task. These findings suggest that, although the brain circuits involved in Japanese typewriting are almost the same as those involved in handwriting, there are brain regions that are specific for typewriting.

Peripheral nerve injury induces glial activation in primary motor cortex

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Julieta Troncoso

2015-02-01

Full Text Available Preliminary evidence suggests that peripheral facial nerve injuries are associated with sensorimotor cortex reorganization. We have characterized facial nerve lesion-induced structural changes in primary motor cortex layer 5 pyramidal neurons and their relationship with glial cell density using a rodent facial paralysis model. First, we used adult transgenic mice expressing green fluorescent protein in microglia and yellow fluorescent protein in pyramidal neurons which were subjected to either unilateral lesion of the facial nerve or sham surgery. Two-photon excitation microscopy was then used for evaluating both layer 5 pyramidal neurons and microglia in vibrissal primary motor cortex (vM1. It was found that facial nerve lesion induced long-lasting changes in dendritic morphology of vM1 layer 5 pyramidal neurons and in their surrounding microglia. Pyramidal cells’ dendritic arborization underwent overall shrinkage and transient spine pruning. Moreover, microglial cell density surrounding vM1 layer 5 pyramidal neurons was significantly increased with morphological bias towards the activated phenotype. Additionally, we induced facial nerve lesion in Wistar rats to evaluate the degree and extension of facial nerve lesion-induced reorganization processes in central nervous system using neuronal and glial markers. Immunoreactivity to NeuN (neuronal nuclei antigen, GAP-43 (growth-associated protein 43, GFAP (glial fibrillary acidic protein, and Iba 1 (Ionized calcium binding adaptor molecule 1 were evaluated 1, 3, 7, 14, 28 and 35 days after either unilateral facial nerve lesion or sham surgery. Patches of decreased NeuN immunoreactivity were found bilaterally in vM1 as well as in primary somatosensory cortex (CxS1. Significantly increased GAP-43 immunoreactivity was found bilaterally after the lesion in hippocampus, striatum, and sensorimotor cortex. One day after lesion GFAP immunoreactivity increased bilaterally in hippocampus, subcortical white

Abnormal Brain Activation During Theory of Mind Tasks in Schizophrenia: A Meta-Analysis.

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Kronbichler, Lisa; Tschernegg, Melanie; Martin, Anna Isabel; Schurz, Matthias; Kronbichler, Martin

2017-10-21

Social cognition abilities are severely impaired in schizophrenia (SZ). The current meta-analysis used foci of 21 individual studies on functional abnormalities in the schizophrenic brain in order to identify regions that reveal convergent under- or over-activation during theory of mind (TOM) tasks. Studies were included in the analyses when contrasting tasks that require the processing of mental states with tasks which did not. Only studies that investigated patients with an ICD or DSM diagnosis were included. Quantitative voxel-based meta-analyses were done using Seed-based d Mapping software. Common TOM regions like medial-prefrontal cortex and temporo-parietal junction revealed abnormal activation in schizophrenic patients: Under-activation was identified in the medial prefrontal cortex, left orbito-frontal cortex, and in a small section of the left posterior temporo-parietal junction. Remarkably, robust over-activation was identified in a more dorsal, bilateral section of the temporo-parietal junction. Further abnormal activation was identified in medial occipito-parietal cortex, right premotor areas, left cingulate gyrus, and lingual gyrus. The findings of this study suggest that SZ patients simultaneously show over- and under-activation in TOM-related regions. Especially interesting, temporo-parietal junction reveals diverging activation patterns with an under-activating left posterior and an over-activating bilateral dorsal section. In conclusion, SZ patients show less specialized brain activation in regions linked to TOM and increased activation in attention-related networks suggesting compensatory effects. © The Author 2017. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center.

Benefits of physical exercise on the aging brain: the role of the prefrontal cortex.

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Berchicci, Marika; Lucci, Giuliana; Di Russo, Francesco

2013-11-01

Motor planning in older adults likely relies on the overengagement of the prefrontal cortex (PFC) and is associated with slowness of movement and responses. Does a physically active lifestyle counteract the overrecruitment of the PFC during action preparation? This study used high-resolution electroencephalography to measure the effect of physical exercise on the executive functions of the PFC preceding a visuomotor discriminative task. A total of 130 participants aged 15-86 were divided into two groups based on physical exercise participation. The response times and accuracy and the premotor activity of the PFC were separately correlated with age for the two groups. The data were first fit with a linear function and then a higher order polynomial function. We observed that after 35-40 years of age, physically active individuals have faster response times than their less active peers and showed no signs of PFC hyperactivity during motor planning. The present findings show that physical exercise could speed up the response of older people and reveal that also in middle-aged people, moderate-to-high levels of physical exercise benefits the planning/execution of a response and the executive functions mediated by the PFC, counteracting the neural overactivity often observed in the elderly adults.

Nociceptive afferents to the premotor neurons that send axons simultaneously to the facial and hypoglossal motoneurons by means of axon collaterals.

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Yulin Dong

Full Text Available It is well known that the brainstem premotor neurons of the facial nucleus and hypoglossal nucleus coordinate orofacial nociceptive reflex (ONR responses. However, whether the brainstem PNs receive the nociceptive projection directly from the caudal spinal trigeminal nucleus is still kept unclear. Our present study focuses on the distribution of premotor neurons in the ONR pathways of rats and the collateral projection of the premotor neurons which are involved in the brainstem local pathways of the orofacial nociceptive reflexes of rat. Retrograde tracer Fluoro-gold (FG or FG/tetramethylrhodamine-dextran amine (TMR-DA were injected into the VII or/and XII, and anterograde tracer biotinylated dextran amine (BDA was injected into the caudal spinal trigeminal nucleus (Vc. The tracing studies indicated that FG-labeled neurons receiving BDA-labeled fibers from the Vc were mainly distributed bilaterally in the parvicellular reticular formation (PCRt, dorsal and ventral medullary reticular formation (MdD, MdV, supratrigeminal nucleus (Vsup and parabrachial nucleus (PBN with an ipsilateral dominance. Some FG/TMR-DA double-labeled premotor neurons, which were observed bilaterally in the PCRt, MdD, dorsal part of the MdV, peri-motor nucleus regions, contacted with BDA-labeled axonal terminals and expressed c-fos protein-like immunoreactivity which induced by subcutaneous injection of formalin into the lip. After retrograde tracer wheat germ agglutinated horseradish peroxidase (WGA-HRP was injected into VII or XII and BDA into Vc, electron microscopic study revealed that some BDA-labeled axonal terminals made mainly asymmetric synapses on the dendritic and somatic profiles of WGA-HRP-labeled premotor neurons. These data indicate that some premotor neurons could integrate the orofacial nociceptive input from the Vc and transfer these signals simultaneously to different brainstem motonuclei by axonal collaterals.

Effect of Different Mental Imagery Speeds on the Motor Performance: Investigation of the Role of Mirror Neurons

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Sajad Parsaei

2017-09-01

Conclusion: The results of this study showed that mirror neurons within the premotor cortex are an important neural mechanism in the brain activity pattern, which causes the effectiveness of imagery in the improvement of motor skills.  

Anticipatory activity in rat medial prefrontal cortex during a working memory task

Institute of Scientific and Technical Information of China (English)

Wenwen Bai; Tiaotiao Liu; Hu Yi; Shuangyan Li; Xin Tian

2012-01-01

Objective Working memory is a key cognitive function in which the prefrontal cortex plays a crucial role.This study aimed to show the firing patterns of a neuronal population in the prefrontal cortex of the rat in a working memory task and to explore how a neuronal ensemble encodes a working memory event.Methods Sprague-Dawley rats were trained in a Y-maze until they reached an 80％ correct rate in a working memory task.Then a 16-channel microelectrode array was implanted in the prefrontal cortex.After recovery,neuronal population activity was recorded during the task,using the Cerebus data-acquisition system.Spatio-temporal trains of action potentials were obtained from the original neuronal population signals.Results During the Y-maze working memory task,some neurons showed significantly increased firing rates and evident neuronal ensemble activity.Moreover,the anticipatory activity was associated with the delayed alternate choice of the upcoming movement.In correct trials,the averaged pre-event firing rate (10.86 ± 1.82 spikes/bin) was higher than the post-event rate (8.17 ± 1.15 spikes/bin) (P ＜0.05).However,in incorrect trials,the rates did not differ.Conclusion The results indicate that the anticipatory activity of a neuronal ensemble in the prefrontal cortex may play a role in encoding working memory events.

Patchwork-Type Spontaneous Activity in Neonatal Barrel Cortex Layer 4 Transmitted via Thalamocortical Projections

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Hidenobu Mizuno

2018-01-01

Full Text Available Summary: Establishment of precise neuronal connectivity in the neocortex relies on activity-dependent circuit reorganization during postnatal development; however, the nature of cortical activity during this period remains largely unknown. Using two-photon calcium imaging of the barrel cortex in vivo during the first postnatal week, we reveal that layer 4 (L4 neurons within the same barrel fire synchronously in the absence of peripheral stimulation, creating a “patchwork” pattern of spontaneous activity corresponding to the barrel map. By generating transgenic mice expressing GCaMP6s in thalamocortical axons, we show that thalamocortical axons also demonstrate the spontaneous patchwork activity pattern. Patchwork activity is diminished by peripheral anesthesia but is mostly independent of self-generated whisker movements. The patchwork activity pattern largely disappeared during postnatal week 2, as even L4 neurons within the same barrel tended to fire asynchronously. This spontaneous L4 activity pattern has features suitable for thalamocortical (TC circuit refinement in the neonatal barrel cortex. : By two-photon calcium imaging of layer 4 neurons and thalamocortical axon terminals in neonatal mouse barrel cortex, Mizuno et al. find a patchwork-like spontaneous activity pattern corresponding to the barrel map, which may be important for thalamocortical circuit maturation. Keywords: activity-dependent development, spontaneous activity, synchronized activity, barrel cortex, thalamocortical axons, neonates, in vivo calcium imaging, awake, single-cell labeling, whisker monitoring

Changes in cue-induced, prefrontal cortex activity with video-game play.

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Han, Doug Hyun; Kim, Yang Soo; Lee, Yong Sik; Min, Kyung Joon; Renshaw, Perry F

2010-12-01

Brain responses, particularly within the orbitofrontal and cingulate cortices, to Internet video-game cues in college students are similar to those observed in patients with substance dependence in response to the substance-related cues. In this study, we report changes in brain activity between baseline and following 6 weeks of Internet video-game play. We hypothesized that subjects with high levels of self-reported craving for Internet video-game play would be associated with increased activity in the prefrontal cortex, particularly the orbitofrontal and anterior cingulate cortex. Twenty-one healthy university students were recruited. At baseline and after a 6-week period of Internet video-game play, brain activity during presentation of video-game cues was assessed using 3T blood oxygen level dependent functional magnetic resonance imaging. Craving for Internet video-game play was assessed by self-report on a 7-point visual analogue scale following cue presentation. During a standardized 6-week video-game play period, brain activity in the anterior cingulate and orbitofrontal cortex of the excessive Internet game-playing group (EIGP) increased in response to Internet video-game cues. In contrast, activity observed in the general player group (GP) was not changed or decreased. In addition, the change of craving for Internet video games was positively correlated with the change in activity of the anterior cingulate in all subjects. These changes in frontal-lobe activity with extended video-game play may be similar to those observed during the early stages of addiction.

Alpha, beta and gamma electrocorticographic rhythms in somatosensory, motor, premotor and prefrontal cortical areas differ in movement execution and observation in humans.

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Babiloni, Claudio; Del Percio, Claudio; Vecchio, Fabrizio; Sebastiano, Fabio; Di Gennaro, Giancarlo; Quarato, Pier P; Morace, Roberta; Pavone, Luigi; Soricelli, Andrea; Noce, Giuseppe; Esposito, Vincenzo; Rossini, Paolo Maria; Gallese, Vittorio; Mirabella, Giovanni

2016-01-01

In the present study, we tested the hypothesis that both movement execution and observation induce parallel modulations of alpha, beta, and gamma electrocorticographic (ECoG) rhythms in primary somatosensory (Brodmann area 1-2, BA1-2), primary motor (BA4), ventral premotor (BA6), and prefrontal (BA44 and BA45, part of putative human mirror neuron system underlying the understanding of actions of other people) areas. ECoG activity was recorded in drug-resistant epileptic patients during the execution of actions to reach and grasp common objects according to their affordances, as well as during the observation of the same actions performed by an experimenter. Both action execution and observation induced a desynchronization of alpha and beta rhythms in BA1-2, BA4, BA6, BA44 and BA45, which was generally higher in amplitude during the former than the latter condition. Action execution also induced a major synchronization of gamma rhythms in BA4 and BA6, again more during the execution of an action than during its observation. Human primary sensorimotor, premotor, and prefrontal areas do generate alpha, beta, and gamma rhythms and differently modulate them during action execution and observation. Gamma rhythms of motor areas are especially involved in action execution. Oscillatory activity of neural populations in sensorimotor, premotor and prefrontal (part of human mirror neuron system) areas represents and distinguishes own actions from those of other people. This methodological approach might be used for a neurophysiological diagnostic imaging of social cognition in epileptic patients. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Visual short-term memory: activity supporting encoding and maintenance in retinotopic visual cortex.

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Sneve, Markus H; Alnæs, Dag; Endestad, Tor; Greenlee, Mark W; Magnussen, Svein

2012-10-15

Recent studies have demonstrated that retinotopic cortex maintains information about visual stimuli during retention intervals. However, the process by which transient stimulus-evoked sensory responses are transformed into enduring memory representations is unknown. Here, using fMRI and short-term visual memory tasks optimized for univariate and multivariate analysis approaches, we report differential involvement of human retinotopic areas during memory encoding of the low-level visual feature orientation. All visual areas show weaker responses when memory encoding processes are interrupted, possibly due to effects in orientation-sensitive primary visual cortex (V1) propagating across extrastriate areas. Furthermore, intermediate areas in both dorsal (V3a/b) and ventral (LO1/2) streams are significantly more active during memory encoding compared with non-memory (active and passive) processing of the same stimulus material. These effects in intermediate visual cortex are also observed during memory encoding of a different stimulus feature (spatial frequency), suggesting that these areas are involved in encoding processes on a higher level of representation. Using pattern-classification techniques to probe the representational content in visual cortex during delay periods, we further demonstrate that simply initiating memory encoding is not sufficient to produce long-lasting memory traces. Rather, active maintenance appears to underlie the observed memory-specific patterns of information in retinotopic cortex. Copyright © 2012 Elsevier Inc. All rights reserved.

Seeing or moving in parallel

DEFF Research Database (Denmark)

Christensen, Mark Schram; Ehrsson, H Henrik; Nielsen, Jens Bo

2013-01-01

a different network, involving bilateral dorsal premotor cortex (PMd), primary motor cortex, and SMA, was more active when subjects viewed parallel movements while performing either symmetrical or parallel movements. Correlations between behavioral instability and brain activity were present in right lateral...... adduction-abduction movements symmetrically or in parallel with real-time congruent or incongruent visual feedback of the movements. One network, consisting of bilateral superior and middle frontal gyrus and supplementary motor area (SMA), was more active when subjects performed parallel movements, whereas...

High-intensity Erotic Visual Stimuli De-activate the Primary Visual Cortex in Women

NARCIS (Netherlands)

Huynh, Hieu K.; Beers, Caroline; Willemsen, Antoon; Lont, Erna; Laan, Ellen; Dierckx, Rudi; Jansen, Monique; Sand, Michael; Schultz, Willibrord Weijmar; Holstege, Gert

Introduction. The primary visual cortex, Brodmann's area (BA 17), plays a vital role in basic survival mechanisms in humans. In most neuro-imaging studies in which the volunteers have to watch pictures or movies, the primary visual cortex is similarly activated independent of the content of the

High-intensity Erotic Visual Stimuli De-activate the Primary Visual Cortex in Women

NARCIS (Netherlands)

Huynh, Hieu K.; Beers, Caroline; Willemsen, Antoon; Lont, Erna; Laan, Ellen; Dierckx, Rudi; Jansen, Monique; Sand, Michael; Weijmar Schultz, Willibrord; Holstege, Gert

2012-01-01

Introduction. The primary visual cortex, Brodmann's area (BA 17), plays a vital role in basic survival mechanisms in humans. In most neuro-imaging studies in which the volunteers have to watch pictures or movies, the primary visual cortex is similarly activated independent of the content of the

Specific and differential activation of mitogen-activated protein kinase cascades by unfamiliar taste in the insular cortex of the behaving rat.

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Berman, D E; Hazvi, S; Rosenblum, K; Seger, R; Dudai, Y

1998-12-01

Rats were given to drink an unfamiliar taste solution under conditions that result in long-term memory of that taste. The insular cortex, which contains the taste cortex, was then removed and assayed for activation of mitogen-activated protein kinase (MAPK) cascades by using antibodies to the activated forms of various MAPKs. Extracellular responsive kinase 1-2 (ERK1-2) in the cortical homogenate was significantly activated within taste solution, without alteration in the total level of the ERK1-2 proteins. The activity subsided to basal levels within ERK1-2 was not activated when the taste was made familiar. The effect of the unfamiliar taste was specific to the insular cortex. Jun N-terminal kinase 1-2 (JNK1-2) was activated by drinking the taste but with a delayed time course, whereas the activity of Akt kinase and p38MAPK remained unchanged. Elk-1, a member of the ternary complex factor and an ERK/JNK downstream substrate, was activated with a time course similar to that of ERK1-2. Microinjection of a reversible inhibitor of MAPK/ERK kinase into the insular cortex shortly before exposure to the novel taste in a conditioned taste aversion training paradigm attenuated long-term taste aversion memory without significantly affecting short-term memory or the sensory, motor, and motivational faculties required to express long-term taste aversion memory. It was concluded that ERK and JNK are specifically and differentially activated in the insular cortex after exposure to a novel taste, and that this activation is required for consolidation of long-term taste memory.

Metabolic activity in striate and extrastriate cortex in the hooded rat: contralateral and ipsilateral eye input

International Nuclear Information System (INIS)

Thurlow, G.A.; Cooper, R.M.

1988-01-01

The extent of changes in glucose metabolism resulting from ipsilateral and contralateral eye activity in the posterior cortex of the hooded rat was demonstrated by means of the C-14 2-deoxyglucose autoradiographic technique. By stimulating one eye with square wave gratings and eliminating efferent activation from the other by means of enucleation or intraocular TTX injection, differences between ipsilaterally and contralaterally based visual activity in the two hemispheres were maximized. Carbon-14 levels in layer IV of autoradiographs of coronal sections were measured and combined across sections to form right and left matrices of posterior cortex metabolic activity. A difference matrix, formed by subtracting the metabolic activity matrix of cortex contralateral to the stimulated eye from the ipsilateral depressed matrix, emphasized those parts of the visual cortex that received monocular visual input. The demarcation of striate cortex by means of cholinesterase stain and the examination of autoradiographs from sections cut tangential to the cortical surface aided in the interpretation of the difference matrices. In striate cortex, differences were maximal in the medial monocular portion, and the lateral or binocular portion was shown to be divided metabolically into a far lateral contralaterally dominant strip along the cortical representation of the vertical meridian, and a more medial region of patches of more or less contralaterally dominant binocular input. Lateral peristriate differences were less than those of striate cortex, and regions of greater and lesser monocular input could be distinguished. We did not detect differences between the two hemispheres in either anterior or medial peristriate areas

Reading a suspenseful literary text activates brain areas related to social cognition and predictive inference.

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Moritz Lehne

Full Text Available Stories can elicit powerful emotions. A key emotional response to narrative plots (e.g., novels, movies, etc. is suspense. Suspense appears to build on basic aspects of human cognition such as processes of expectation, anticipation, and prediction. However, the neural processes underlying emotional experiences of suspense have not been previously investigated. We acquired functional magnetic resonance imaging (fMRI data while participants read a suspenseful literary text (E.T.A. Hoffmann's "The Sandman" subdivided into short text passages. Individual ratings of experienced suspense obtained after each text passage were found to be related to activation in the medial frontal cortex, bilateral frontal regions (along the inferior frontal sulcus, lateral premotor cortex, as well as posterior temporal and temporo-parietal areas. The results indicate that the emotional experience of suspense depends on brain areas associated with social cognition and predictive inference.

Changes in brain activity in response to problem solving during the abstinence from online game play.

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Kim, Sun Mi; Han, Doug Hyun; Lee, Young Sik; Kim, Jieun E; Renshaw, Perry F

2012-06-01

Several studies have suggested that addictive disorders including substance abuse and pathologic gambling might be associated with dysfunction on working memory and prefrontal activity. We hypothesized that excessive online game playing is associated with deficits in prefrontal cortex function and that recovery from excessive online game playing might improve prefrontal cortical activation in response to working memory stimulation. Thirteen adolescents with excessive online game playing (AEOP) and ten healthy adolescents (HC) agreed to participate in this study. The severity of online game play and playing time were evaluated for a baseline measurement and again following four weeks of treatment. Brain activation in response to working memory tasks (simple and complex calculations) at baseline and subsequent measurements was assessed using BOLD functional magnetic resonance imaging (fMRI). Compared to the HC subjects, the AEOP participants exhibited significantly greater activity in the right middle occipital gyrus, left cerebellum posterior lobe, left premotor cortex and left middle temporal gyrus in response to working memory tasks during baseline measurements. After four weeks of treatment, the AEOP subjects showed increased activity within the right dorsolateral prefrontal cortex and left occipital fusiform gyrus. After four weeks of treatment, changes in the severity of online game playing were negatively correlated with changes in the mean β value of the right dorsolateral prefrontal cortex in response to complex stimulation. We suggest that the effects of online game addiction on working memory may be similar to those observed in patients with substance dependence.

Brain activation during anticipation of sound sequences.

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Leaver, Amber M; Van Lare, Jennifer; Zielinski, Brandon; Halpern, Andrea R; Rauschecker, Josef P

2009-02-25

Music consists of sound sequences that require integration over time. As we become familiar with music, associations between notes, melodies, and entire symphonic movements become stronger and more complex. These associations can become so tight that, for example, hearing the end of one album track can elicit a robust image of the upcoming track while anticipating it in total silence. Here, we study this predictive "anticipatory imagery" at various stages throughout learning and investigate activity changes in corresponding neural structures using functional magnetic resonance imaging. Anticipatory imagery (in silence) for highly familiar naturalistic music was accompanied by pronounced activity in rostral prefrontal cortex (PFC) and premotor areas. Examining changes in the neural bases of anticipatory imagery during two stages of learning conditional associations between simple melodies, however, demonstrates the importance of fronto-striatal connections, consistent with a role of the basal ganglia in "training" frontal cortex (Pasupathy and Miller, 2005). Another striking change in neural resources during learning was a shift between caudal PFC earlier to rostral PFC later in learning. Our findings regarding musical anticipation and sound sequence learning are highly compatible with studies of motor sequence learning, suggesting common predictive mechanisms in both domains.

Spontaneous high-gamma band activity reflects functional organization of auditory cortex in the awake macaque.

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Fukushima, Makoto; Saunders, Richard C; Leopold, David A; Mishkin, Mortimer; Averbeck, Bruno B

2012-06-07

In the absence of sensory stimuli, spontaneous activity in the brain has been shown to exhibit organization at multiple spatiotemporal scales. In the macaque auditory cortex, responses to acoustic stimuli are tonotopically organized within multiple, adjacent frequency maps aligned in a caudorostral direction on the supratemporal plane (STP) of the lateral sulcus. Here, we used chronic microelectrocorticography to investigate the correspondence between sensory maps and spontaneous neural fluctuations in the auditory cortex. We first mapped tonotopic organization across 96 electrodes spanning approximately two centimeters along the primary and higher auditory cortex. In separate sessions, we then observed that spontaneous activity at the same sites exhibited spatial covariation that reflected the tonotopic map of the STP. This observation demonstrates a close relationship between functional organization and spontaneous neural activity in the sensory cortex of the awake monkey. Copyright © 2012 Elsevier Inc. All rights reserved.

Visual feedback alters force control and functional activity in the visuomotor network after stroke

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Derek B. Archer

2018-01-01

Full Text Available Modulating visual feedback may be a viable option to improve motor function after stroke, but the neurophysiological basis for this improvement is not clear. Visual gain can be manipulated by increasing or decreasing the spatial amplitude of an error signal. Here, we combined a unilateral visually guided grip force task with functional MRI to understand how changes in the gain of visual feedback alter brain activity in the chronic phase after stroke. Analyses focused on brain activation when force was produced by the most impaired hand of the stroke group as compared to the non-dominant hand of the control group. Our experiment produced three novel results. First, gain-related improvements in force control were associated with an increase in activity in many regions within the visuomotor network in both the stroke and control groups. These regions include the extrastriate visual cortex, inferior parietal lobule, ventral premotor cortex, cerebellum, and supplementary motor area. Second, the stroke group showed gain-related increases in activity in additional regions of lobules VI and VIIb of the ipsilateral cerebellum. Third, relative to the control group, the stroke group showed increased activity in the ipsilateral primary motor cortex, and activity in this region did not vary as a function of visual feedback gain. The visuomotor network, cerebellum, and ipsilateral primary motor cortex have each been targeted in rehabilitation interventions after stroke. Our observations provide new insight into the role these regions play in processing visual gain during a precisely controlled visuomotor task in the chronic phase after stroke.

Brain activation during fast driving in a driving simulator: the role of the lateral prefrontal cortex.

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Jäncke, Lutz; Brunner, Béatrice; Esslen, Michaela

2008-07-16

Little is currently known about the neural underpinnings of the cognitive control of driving behavior in realistic situations and of the driver's speeding behavior in particular. In this study, participants drove in realistic scenarios presented in a high-end driving simulator. Scalp-recorded EEG oscillations in the alpha-band (8-13 Hz) with a 30-electrode montage were recorded while the participants drove under different conditions: (i) excessively fast (Fast), (ii) in a controlled manner at a safe speed (Correct), and (iii) impatiently in the context of testing traffic conditions (Impatient). Intracerebral sources of alpha-band activation were estimated using low resolution electrical tomography. Given that previous studies have shown a strong negative correlation between the Bold response in the frontal cortex and the alpha-band power, we used alpha-band-related activity as an estimation of frontal activation. Statistical analysis revealed more alpha-band-related activity (i.e. less neuronal activation) in the right lateral prefrontal cortex, including the dorsolateral prefrontal cortex, during fast driving. Those participants who speeded most and exhibited greater risk-taking behavior demonstrated stronger alpha-related activity (i.e. less neuronal activation) in the left anterior lateral prefrontal cortex. These findings are discussed in the context of current theories about the role of the lateral prefrontal cortex in controlling risk-taking behavior, task switching, and multitasking.

Plasticity of premotor cortico-muscular coherence in severely impaired stroke patients with hand paralysis

Directory of Open Access Journals (Sweden)

Paolo Belardinelli

2017-01-01

In conclusion, functionally relevant modulations of CMC can be detected in patients with long-term, severe motor deficits after a brain-robot assisted rehabilitation training. Premotor beta-band CMC may serve as a biomarker and therapeutic target for novel treatment approaches in this patient group.

Semantic strategy training increases memory performance and brain activity in patients with prefrontal cortex lesions.

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Miotto, Eliane C; Savage, Cary R; Evans, Jonathan J; Wilson, Barbara A; Martin, Maria G M; Balardin, Joana B; Barros, Fabio G; Garrido, Griselda; Teixeira, Manoel J; Amaro Junior, Edson

2013-03-01

Memory deficit is a frequent cognitive disorder following acquired prefrontal cortex lesions. In the present study, we investigated the brain correlates of a short semantic strategy training and memory performance of patients with distinct prefrontal cortex lesions using fMRI and cognitive tests. Twenty-one adult patients with post-acute prefrontal cortex (PFC) lesions, twelve with left dorsolateral PFC (LPFC) and nine with bilateral orbitofrontal cortex (BOFC) were assessed before and after a short cognitive semantic training using a verbal memory encoding paradigm during scanning and neuropsychological tests outside the scanner. After the semantic strategy training both groups of patients showed significant behavioral improvement in verbal memory recall and use of semantic strategies. In the LPFC group, greater activity in left inferior and medial frontal gyrus, precentral gyrus and insula was found after training. For the BOFC group, a greater activation was found in the left parietal cortex, right cingulated and precuneus after training. The activation of these specific areas in the memory and executive networks following cognitive training was associated to compensatory brain mechanisms and application of the semantic strategy. Copyright © 2012 Elsevier B.V. All rights reserved.

Reafferent copies of imitated actions in the right superior temporal cortex

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Iacoboni, Marco; Koski, Lisa M.; Brass, Marcel; Bekkering, Harold; Woods, Roger P.; Dubeau, Marie-Charlotte; Mazziotta, John C.; Rizzolatti, Giacomo

2001-01-01

Imitation is a complex phenomenon, the neural mechanisms of which are still largely unknown. When individuals imitate an action that already is present in their motor repertoire, a mechanism matching the observed action onto an internal motor representation of that action should suffice for the purpose. When one has to copy a new action, however, or to adjust an action present in one's motor repertoire to a different observed action, an additional mechanism is needed that allows the observer to compare the action made by another individual with the sensory consequences of the same action made by himself. Previous experiments have shown that a mechanism that directly matches observed actions on their motor counterparts exists in the premotor cortex of monkeys and humans. Here we report the results of functional magnetic resonance experiments, suggesting that in the superior temporal sulcus, a higher order visual region, there is a sector that becomes active both during hand action observation and during imitation even in the absence of direct vision of the imitator's hand. The motor-related activity is greater during imitation than during control motor tasks. This newly identified region has all the requisites for being the region at which the observed actions, and the reafferent motor-related copies of actions made by the imitator, interact. PMID:11717457

The influence of spontaneous activity on stimulus processing in primary visual cortex.

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Schölvinck, M L; Friston, K J; Rees, G

2012-02-01

Spontaneous activity in the resting human brain has been studied extensively; however, how such activity affects the local processing of a sensory stimulus is relatively unknown. Here, we examined the impact of spontaneous activity in primary visual cortex on neuronal and behavioural responses to a simple visual stimulus, using functional MRI. Stimulus-evoked responses remained essentially unchanged by spontaneous fluctuations, combining with them in a largely linear fashion (i.e., with little evidence for an interaction). However, interactions between spontaneous fluctuations and stimulus-evoked responses were evident behaviourally; high levels of spontaneous activity tended to be associated with increased stimulus detection at perceptual threshold. Our results extend those found in studies of spontaneous fluctuations in motor cortex and higher order visual areas, and suggest a fundamental role for spontaneous activity in stimulus processing. Copyright © 2011. Published by Elsevier Inc.

Functional Anatomy of Writing with the Dominant Hand

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Najee-ullah, Muslimah ‘Ali; Hallett, Mark

2013-01-01

While writing performed by any body part is similar in style, indicating a common program, writing with the dominant hand is particularly skilled. We hypothesized that this skill utilizes a special motor network supplementing the motor equivalence areas. Using functional magnetic resonance imaging in 13 normal subjects, we studied nine conditions: writing, zigzagging and tapping, each with the right hand, left hand and right foot. We identified brain regions activated with the right (dominant) hand writing task, exceeding the activation common to right-hand use and the writing program, both identified without right-hand writing itself. Right-hand writing significantly differed from the other tasks. First, we observed stronger activations in the left dorsal prefrontal cortex, left intraparietal sulcus and right cerebellum. Second, the left anterior putamen was required to initiate all the tested tasks, but only showed sustained activation during the right-hand writing condition. Lastly, an exploratory analysis showed clusters in the left ventral premotor cortex and inferior and superior parietal cortices were only significantly active for right-hand writing. The increased activation with right-hand writing cannot be ascribed to increased effort, since this is a well-practiced task much easier to perform than some of the other tasks studied. Because parietal-premotor connections code for particular skills, it would seem that the parietal and premotor regions, together with basal ganglia-sustained activation likely underlie the special skill of handwriting with the dominant hand. PMID:23844132

Functional anatomy of writing with the dominant hand.

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Horovitz, Silvina G; Gallea, Cecile; Najee-Ullah, Muslimah 'ali; Hallett, Mark

2013-01-01

While writing performed by any body part is similar in style, indicating a common program, writing with the dominant hand is particularly skilled. We hypothesized that this skill utilizes a special motor network supplementing the motor equivalence areas. Using functional magnetic resonance imaging in 13 normal subjects, we studied nine conditions: writing, zigzagging and tapping, each with the right hand, left hand and right foot. We identified brain regions activated with the right (dominant) hand writing task, exceeding the activation common to right-hand use and the writing program, both identified without right-hand writing itself. Right-hand writing significantly differed from the other tasks. First, we observed stronger activations in the left dorsal prefrontal cortex, left intraparietal sulcus and right cerebellum. Second, the left anterior putamen was required to initiate all the tested tasks, but only showed sustained activation during the right-hand writing condition. Lastly, an exploratory analysis showed clusters in the left ventral premotor cortex and inferior and superior parietal cortices were only significantly active for right-hand writing. The increased activation with right-hand writing cannot be ascribed to increased effort, since this is a well-practiced task much easier to perform than some of the other tasks studied. Because parietal-premotor connections code for particular skills, it would seem that the parietal and premotor regions, together with basal ganglia-sustained activation likely underlie the special skill of handwriting with the dominant hand.

Neuron activity in rat hippocampus and motor cortex during discrimination reversal.

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Disterhoft, J F; Segal, M

1978-01-01

Chronic unit activity and gross movement were recorded from rats during two discrimination reversals in a classical appetitive conditioning situation. The anticipatory movement decreased in response to the former CS+ tone and increased to the previous CS- tone after each reversal. Hippocampus and motor cortex were differently related to these two kinds of behavioral change. Response rates of hippocampal neurons were more closely related to the increased movement response to the former CS- which now signaled food. Motor cortex neuron responses were more closely correlated with the decrease in movement responses to the former CS+ which became neutral after the reversal. It appeared that hippocampal neurons could have been involved in one cognitive aspect of the situation, motor cortex neurons in another. The data were related to current functional concepts of these brain regions.

The organization of the posterior parietal cortex devoted to upper limb actions: An fMRI study

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Ferri, Stefania; Rizzolatti, Giacomo

2015-01-01

Abstract The present fMRI study examined whether upper‐limb action classes differing in their motor goal are encoded by different PPC sectors. Action observation was used as a proxy for action execution. Subjects viewed actors performing object‐related (e.g., grasping), skin‐displacing (e.g., rubbing the skin), and interpersonal upper limb actions (e.g., pushing someone). Observation of the three action classes activated a three‐level network including occipito‐temporal, parietal, and premotor cortex. The parietal region common to observing all three action classes was located dorsally to the left intraparietal sulcus (DIPSM/DIPSA border). Regions specific for observing an action class were obtained by combining the interaction between observing action classes and stimulus types with exclusive masking for observing the other classes, while for regions considered preferentially active for a class the interaction was exclusively masked with the regions common to all observed actions. Left putative human anterior intraparietal was specific for observing manipulative actions, and left parietal operculum including putative human SII region, specific for observing skin‐displacing actions. Control experiments demonstrated that this latter activation depended on seeing the skin being moved and not simply on seeing touch. Psychophysiological interactions showed that the two specific parietal regions had similar connectivities. Finally, observing interpersonal actions preferentially activated a dorsal sector of left DIPSA, possibly the homologue of ventral intraparietal coding the impingement of the target person's body into the peripersonal space of the actor. These results support the importance of segregation according to the action class as principle of posterior parietal cortex organization for action observation and by implication for action execution. Hum Brain Mapp 36:3845–3866, 2015. © 2015 The Authors Human Brain Mapping Published by Wiley

Change in brain network connectivity during PACAP38-induced migraine attacks

DEFF Research Database (Denmark)

Amin, Faisal Mohammad; Hougaard, Anders; Magon, Stefano

2016-01-01

OBJECTIVE: To investigate resting-state functional connectivity in the salience network (SN), the sensorimotor network (SMN), and the default mode network (DMN) during migraine attacks induced by pituitary adenylate cyclase-activating polypeptide-38 (PACAP38). METHODS: In a double-blind, randomized...... connectivity with the bilateral opercular part of the inferior frontal gyrus in the SN. In SMN, there was increased connectivity with the right premotor cortex and decreased connectivity with the left visual cortex. Several areas showed increased (left primary auditory, secondary somatosensory, premotor......, and visual cortices) and decreased (right cerebellum and left frontal lobe) connectivity with DMN. We found no resting-state network changes after VIP (n = 15). CONCLUSIONS: PACAP38-induced migraine attack is associated with altered connectivity of several large-scale functional networks of the brain....

The time course of activity in dorsolateral prefrontal cortex and anterior cingulate cortex during top-down attentional control.

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Silton, Rebecca Levin; Heller, Wendy; Towers, David N; Engels, Anna S; Spielberg, Jeffrey M; Edgar, J Christopher; Sass, Sarah M; Stewart, Jennifer L; Sutton, Bradley P; Banich, Marie T; Miller, Gregory A

2010-04-15

A network of brain regions has been implicated in top-down attentional control, including left dorsolateral prefrontal cortex (LDLPFC) and dorsal anterior cingulate cortex (dACC). The present experiment evaluated predictions of the cascade-of-control model (Banich, 2009), which predicts that during attentionally-demanding tasks, LDLPFC imposes a top-down attentional set which precedes late-stage selection performed by dACC. Furthermore, the cascade-of-control model argues that dACC must increase its activity to compensate when top-down control by LDLPFC is poor. The present study tested these hypotheses using fMRI and dense-array ERP data collected from the same 80 participants in separate sessions. fMRI results guided ERP source modeling to characterize the time course of activity in LDLPFC and dACC. As predicted, dACC activity subsequent to LDLPFC activity distinguished congruent and incongruent conditions on the Stroop task. Furthermore, when LDLPFC activity was low, the level of dACC activity was related to performance outcome. These results demonstrate that dACC responds to attentional demand in a flexible manner that is dependent on the level of LDLPFC activity earlier in a trial. Overall, results were consistent with the temporal course of regional brain function proposed by the cascade-of-control model. Copyright 2009 Elsevier Inc. All rights reserved.

Layer-specificity in the effects of attention and working memory on activity in primary visual cortex

NARCIS (Netherlands)

van Kerkoerle, Timo; Self, Matthew W.; Roelfsema, Pieter R.

2017-01-01

Neuronal activity in early visual cortex depends on attention shifts but the contribution to working memory has remained unclear. Here, we examine neuronal activity in the different layers of the primary visual cortex (V1) in an attention-demanding and a working memory task. A current-source density

Layer-specificity in the effects of attention and working memory on activity in primary visual cortex.

NARCIS (Netherlands)

Van Kerkoerle, Timo; Self, M.W.; Roelfsema, P.R.

2017-01-01

Neuronal activity in early visual cortex depends on attention shifts but the contribution to working memory has remained unclear. Here, we examine neuronal activity in the different layers of the primary visual cortex (V1) in an attention-demanding and a working memory task. A current-source density

Research progress of functional magnetic resonance imaging in cross-modal activation of visual cortex during tactile perception

International Nuclear Information System (INIS)

Zhan Jie; Gong Honghan

2013-01-01

An increasing amount of neuroimaging studies recently demonstrated activation of visual cortex in both blind and sighted participants when performing a variety of tactile tasks such as Braille reading and tactile object recognition, which indicates that visual cortex not only receives visual information, but may participate in tactile perception. To address these cross-modal changes of visual cortex and the neurophysiological mechanisms, many researchers conducted explosive studies using functional magnetic resonance imaging (fMRI) and have made some achievements. This review focuses on cross-modal activation of visual cortex and the underlying mechanisms during tactile perception in both blind and sighted individuals. (authors)

Visual cortex and auditory cortex activation in early binocularly blind macaques: A BOLD-fMRI study using auditory stimuli.

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Wang, Rong; Wu, Lingjie; Tang, Zuohua; Sun, Xinghuai; Feng, Xiaoyuan; Tang, Weijun; Qian, Wen; Wang, Jie; Jin, Lixin; Zhong, Yufeng; Xiao, Zebin

2017-04-15

Cross-modal plasticity within the visual and auditory cortices of early binocularly blind macaques is not well studied. In this study, four healthy neonatal macaques were assigned to group A (control group) or group B (binocularly blind group). Sixteen months later, blood oxygenation level-dependent functional imaging (BOLD-fMRI) was conducted to examine the activation in the visual and auditory cortices of each macaque while being tested using pure tones as auditory stimuli. The changes in the BOLD response in the visual and auditory cortices of all macaques were compared with immunofluorescence staining findings. Compared with group A, greater BOLD activity was observed in the bilateral visual cortices of group B, and this effect was particularly obvious in the right visual cortex. In addition, more activated volumes were found in the bilateral auditory cortices of group B than of group A, especially in the right auditory cortex. These findings were consistent with the fact that there were more c-Fos-positive cells in the bilateral visual and auditory cortices of group B compared with group A (p visual cortices of binocularly blind macaques can be reorganized to process auditory stimuli after visual deprivation, and this effect is more obvious in the right than the left visual cortex. These results indicate the establishment of cross-modal plasticity within the visual and auditory cortices. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Lateralization of brain activity pattern during unilateral movement in Parkinson's disease.

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Wu, Tao; Hou, Yanan; Hallett, Mark; Zhang, Jiarong; Chan, Piu

2015-05-01

We investigated the lateralization of brain activity pattern during performance of unilateral movement in drug-naïve Parkinson's disease (PD) patients with only right hemiparkinsonian symptoms. Functional MRI was obtained when the subjects performed strictly unilateral right hand movement. A laterality index was calculated to examine the lateralization. Patients had decreased activity in the left putamen and left supplementary motor area, but had increased activity in the right primary motor cortex, right premotor cortex, left postcentral gyrus, and bilateral cerebellum. The laterality index was significantly decreased in PD patients compared with controls (0.41 ± 0.14 vs. 0.84 ± 0.09). The connectivity from the left putamen to cortical motor regions and cerebellum was decreased, while the interactions between the cortical motor regions, cerebellum, and right putamen were increased. Our study demonstrates that in early PD, the lateralization of brain activity during unilateral movement is significantly reduced. The dysfunction of the striatum-cortical circuit, decreased transcallosal inhibition, and compensatory efforts from cortical motor regions, cerebellum, and the less affected striatum are likely reasons contributing to the reduced motor lateralization. The disruption of the lateralized brain activity pattern might be a reason underlying some motor deficits in PD, like mirror movements or impaired bilateral motor coordination. © 2015 Wiley Periodicals, Inc.

Synchronous activity in cat visual cortex encodes collinear and cocircular contours.

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Samonds, Jason M; Zhou, Zhiyi; Bernard, Melanie R; Bonds, A B

2006-04-01

We explored how contour information in primary visual cortex might be embedded in the simultaneous activity of multiple cells recorded with a 100-electrode array. Synchronous activity in cat visual cortex was more selective and predictable in discriminating between drifting grating and concentric ring stimuli than changes in firing rate. Synchrony was found even between cells with wholly different orientation preferences when their receptive fields were circularly aligned, and membership in synchronous groups was orientation and curvature dependent. The existence of synchrony between cocircular cells reinforces its role as a general mechanism for contour integration and shape detection as predicted by association field concepts. Our data suggest that cortical synchrony results from common and synchronous input from earlier visual areas and that it could serve to shape extrastriate response selectivity.

Different patterns of auditory cortex activation revealed by functional magnetic resonance imaging

International Nuclear Information System (INIS)

Formisano, E.; Pepino, A.; Bracale, M.; Di Salle, F.; Lanfermann, H.; Zanella, F.E.

1998-01-01

In the last few years, functional Magnetic Resonance Imaging (fMRI) has been widely accepted as an effective tool for mapping brain activities in both the sensorimotor and the cognitive field. The present work aims to assess the possibility of using fMRI methods to study the cortical response to different acoustic stimuli. Furthermore, we refer to recent data collected at Frankfurt University on the cortical pattern of auditory hallucinations. Healthy subjects showed broad bilateral activation, mostly located in the transverse gyrus of Heschl. The analysis of the cortical activation induced by different stimuli has pointed out a remarkable difference in the spatial and temporal features of the auditory cortex response to pulsed tones and pure tones. The activated areas during episodes of auditory hallucinations match the location of primary auditory cortex as defined in control measurements with the same patients and in the experiments on healthy subjects. (authors)

Resting‐state connectivity of pre‐motor cortex reflects disability in multiple sclerosis

DEFF Research Database (Denmark)

Dogonowski, Anne-Marie; Siebner, Hartwig Roman; Soelberg Sørensen, P.

2013-01-01

Objective To characterize the relationship between motor resting-state connectivity of the dorsal pre-motor cortex (PMd) and clinical disability in patients with multiple sclerosis (MS). Materials and methods A total of 27 patients with relapsing–remitting MS (RR-MS) and 15 patients with secondary...... progressive MS (SP-MS) underwent functional resting-state magnetic resonance imaging. Clinical disability was assessed using the Expanded Disability Status Scale (EDSS). Independent component analysis was used to characterize motor resting-state connectivity. Multiple regression analysis was performed in SPM8...... between the individual expression of motor resting-state connectivity in PMd and EDSS scores including age as covariate. Separate post hoc analyses were performed for patients with RR-MS and SP-MS. Results The EDSS scores ranged from 0 to 7 with a median score of 4.3. Motor resting-state connectivity...

Levodopa effects on hand and speech movements in patients with Parkinson's disease: a FMRI study.

Directory of Open Access Journals (Sweden)

Audrey Maillet

Full Text Available Levodopa (L-dopa effects on the cardinal and axial symptoms of Parkinson's disease (PD differ greatly, leading to therapeutic challenges for managing the disabilities in this patient's population. In this context, we studied the cerebral networks associated with the production of a unilateral hand movement, speech production, and a task combining both tasks in 12 individuals with PD, both off and on levodopa (L-dopa. Unilateral hand movements in the off medication state elicited brain activations in motor regions (primary motor cortex, supplementary motor area, premotor cortex, cerebellum, as well as additional areas (anterior cingulate, putamen, associative parietal areas; following L-dopa administration, the brain activation profile was globally reduced, highlighting activations in the parietal and posterior cingulate cortices. For the speech production task, brain activation patterns were similar with and without medication, including the orofacial primary motor cortex (M1, the primary somatosensory cortex and the cerebellar hemispheres bilaterally, as well as the left- premotor, anterior cingulate and supramarginal cortices. For the combined task off L-dopa, the cerebral activation profile was restricted to the right cerebellum (hand movement, reflecting the difficulty in performing two movements simultaneously in PD. Under L-dopa, the brain activation profile of the combined task involved a larger pattern, including additional fronto-parietal activations, without reaching the sum of the areas activated during the simple hand and speech tasks separately. Our results question both the role of the basal ganglia system in speech production and the modulation of task-dependent cerebral networks by dopaminergic treatment.

Study the left prefrontal cortex activity of Chinese children with dyslexia in phonological processing by NIRS

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Zhang, Zhili; Li, Ting; Zheng, Yi; Luo, Qingming; Song, Ranran; Gong, Hui

2006-02-01

Developmental dyslexia, a kind of prevalent psychological disease, represents that dyslexic children have unexpected difficulties in phonological processing and recognition test of Chinese characters. Some functional imaging technologies, such as fMRI and PET, have been used to study the brain activities of the children with dyslexia whose first language is English. In this paper, a portable, 16-channel, continuous-wave (CW) NIRS instrument was used to monitor the concentration changes of each hemoglobin species when Chinese children did the task of phonological processing and recognition test. The NIRS recorded the hemodynamic changes in the left prefrontal cortex of the children. 20 dyslexia-reading children (10~12 years old) and 20 normal-reading children took part in the phonological processing of Chinese characters including the phonological awareness section and the phonological decoding section. During the phonological awareness section, the changed concentration of deoxy-hemoglobin in dyslexia-reading children were significantly higher (p<0.05) than normal-reading children in the left ventrolateral prefrontal cortex (VLPFC). While in the phonological decoding section, both normal and dyslexic reading children had more activity in the left VLPFC, but only normal-reading children had activity in the left middorsal prefrontal cortex. In conclusion, both dyslexic and normal-reading children have activity in the left prefrontal cortex, but the degree and the areas of the prefrontal cortex activity are different between them when they did phonological processing.

GABAA receptors in visual and auditory cortex and neural activity changes during basic visual stimulation

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Pengmin eQin

2012-12-01

Full Text Available Recent imaging studies have demonstrated that levels of resting GABA in the visual cortex predict the degree of stimulus-induced activity in the same region. These studies have used the presentation of discrete visual stimulus; the change from closed eyes to open also represents a simple visual stimulus, however, and has been shown to induce changes in local brain activity and in functional connectivity between regions. We thus aimed to investigate the role of the GABA system, specifically GABAA receptors, in the changes in brain activity between the eyes closed (EC and eyes open (EO state in order to provide detail at the receptor level to complement previous studies of GABA concentrations. We conducted an fMRI study involving two different modes of the change from EC to EO: An EO and EC block design, allowing the modelling of the haemodynamic response, followed by longer periods of EC and EO to allow the measuring of functional connectivity. The same subjects also underwent [18F]Flumazenil PET measure GABAA receptor binding potentials. It was demonstrated that the local-to-global ratio of GABAA receptor binding potential in the visual cortex predicted the degree of changes in neural activity from EC to EO. This same relationship was also shown in the auditory cortex. Furthermore, the local-to-global ratio of GABAA receptor binding potential in the visual cortex also predicts the change of functional connectivity between visual and auditory cortex from EC to EO. These findings contribute to our understanding of the role of GABAA receptors in stimulus-induced neural activity in local regions and in inter-regional functional connectivity.

Prefrontal cortex activation during obstacle negotiation: What's the effect size and timing?

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Maidan, Inbal; Shustak, Shiran; Sharon, Topaz; Bernad-Elazari, Hagar; Geffen, Nimrod; Giladi, Nir; Hausdorff, Jeffrey M; Mirelman, Anat

2018-04-01

Obstacle negotiation is a daily activity that requires the integration of sensorimotor and cognitive information. Recent studies provide evidence for the important role of prefrontal cortex during obstacle negotiation. We aimed to explore the effects of obstacle height and available response time on prefrontal activation. Twenty healthy young adults (age: 30.1 ± 1.0 years; 50% women) walked in an obstacle course while negotiating anticipated and unanticipated obstacles at heights of 50 mm and 100 mm. Prefrontal activation was measured using a functional near-infrared spectroscopy system. Kinect cameras measured the obstacle negotiation strategy. Prefrontal activation was defined based on mean level of HbO 2 before, during and after obstacle negotiation and the HbO 2 slope from gait initiation and throughout the task. Changes between types of obstacles were assessed using linear-mix models and partial correlation analyses evaluated the relationship between prefrontal activation and the distance between the feet as the subjects traversed the obstacles. Different obstacle heights showed similar changes in prefrontal activation measures (p > 0.210). However, during unanticipated obstacles, the slope of the HbO 2 response was steeper (p = 0.048), as compared to anticipated obstacles. These changes in prefrontal activation during negotiation of unanticipated obstacles were correlated with greater distance of the leading foot after the obstacles (r = 0.831, p = 0.041). These findings are the first to show that the pattern of prefrontal activation depends on the nature of the obstacle. More specifically, during unanticipated obstacles the recruitment of the prefrontal cortex is faster and greater than during negotiating anticipated obstacles. These results provide evidence of the important role of the prefrontal cortex and the ability of healthy young adults to tailor the activation pattern to different types of obstacles. Copyright © 2018

Sensory modality specificity of neural activity related to memory in visual cortex.

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Gibson, J R; Maunsell, J H

1997-09-01

Previous studies have shown that when monkeys perform a delayed match-to-sample (DMS) task, some neurons in inferotemporal visual cortex are activated selectively during the delay period when the animal must remember particular visual stimuli. This selective delay activity may be involved in short-term memory. It does not depend on visual stimulation: both auditory and tactile stimuli can trigger selective delay activity in inferotemporal cortex when animals expect to respond to visual stimuli in a DMS task. We have examined the overall modality specificity of delay period activity using a variety of auditory/visual cross-modal and unimodal DMS tasks. The cross-modal DMS tasks involved making specific long-term memory associations between visual and auditory stimuli, whereas the unimodal DMS tasks were standard identity matching tasks. Delay activity existed in auditory/visual cross-modal DMS tasks whether the animal anticipated responding to visual or auditory stimuli. No evidence of selective delay period activation was seen in a purely auditory DMS task. Delay-selective cells were relatively common in one animal where they constituted up to 53% neurons tested with a given task. This was only the case for up to 9% of cells in a second animal. In the first animal, a specific long-term memory representation for learned cross-modal associations was observed in delay activity, indicating that this type of representation need not be purely visual. Furthermore, in this same animal, delay activity in one cross-modal task, an auditory-to-visual task, predicted correct and incorrect responses. These results suggest that neurons in inferotemporal cortex contribute to abstract memory representations that can be activated by input from other sensory modalities, but these representations are specific to visual behaviors.

Categorization and category effects in normal object recognition

DEFF Research Database (Denmark)

Gerlach, Christian; Law, Ian; Gade, Anders

2000-01-01

and that the categorization of artefacts, as opposed to the categorization of natural objects, is based, in part, on action knowledge mediated by the left premotor cortex. However, because artefacts and natural objects often caused activation in the same regions within tasks, processing of these categories is not totally...

Effects of transcranial direct current stimulation of the motor cortex on prefrontal cortex activation during a neuromuscular fatigue task: an fNIRS study.

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Muthalib, Makii; Kan, Benjamin; Nosaka, Kazunori; Perrey, Stephane

2013-01-01

This study investigated whether manipulation of motor cortex excitability by transcranial direct current stimulation (tDCS) modulates neuromuscular fatigue and functional near-infrared spectroscopy (fNIRS)-derived prefrontal cortex (PFC) activation. Fifteen healthy men (27.7 ± 8.4 years) underwent anodal (2 mA, 10 min) and sham (2 mA, first 30 s only) tDCS delivered to the scalp over the right motor cortex. Subjects initially performed a baseline sustained submaximal (30 % maximal voluntary isometric contraction, MVC) isometric contraction task (SSIT) of the left elbow flexors until task failure, which was followed 50 min later by either an anodal or sham treatment condition, then a subsequent posttreatment SSIT. Endurance time (ET), torque integral (TI), and fNIRS-derived contralateral PFC oxygenated (O2Hb) and deoxygenated (HHb) hemoglobin concentration changes were determined at task failure. Results indicated that during the baseline and posttreatment SSIT, there were no significant differences in TI and ET, and increases in fNIRS-derived PFC activation at task failure were observed similarly regardless of the tDCS conditions. This suggests that the PFC neuronal activation to maintain muscle force production was not modulated by anodal tDCS.

Different patterns of auditory cortex activation revealed by functional magnetic resonance imaging

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Formisano, E; Pepino, A; Bracale, M [Department of Electronic Engineering, Biomedical Unit, Universita di Napoli, Federic II, Italy, Via Claudio 21, 80125 Napoli (Italy); Di Salle, F [Department of Biomorphological and Functional Sciences, Radiologucal Unit, Universita di Napoli, Federic II, Italy, Via Claudio 21, 80125 Napoli (Italy); Lanfermann, H; Zanella, F E [Department of Neuroradiology, J.W. Goethe Universitat, Frankfurt/M. (Germany)

1999-12-31

In the last few years, functional Magnetic Resonance Imaging (fMRI) has been widely accepted as an effective tool for mapping brain activities in both the sensorimotor and the cognitive field. The present work aims to assess the possibility of using fMRI methods to study the cortical response to different acoustic stimuli. Furthermore, we refer to recent data collected at Frankfurt University on the cortical pattern of auditory hallucinations. Healthy subjects showed broad bilateral activation, mostly located in the transverse gyrus of Heschl. The analysis of the cortical activation induced by different stimuli has pointed out a remarkable difference in the spatial and temporal features of the auditory cortex response to pulsed tones and pure tones. The activated areas during episodes of auditory hallucinations match the location of primary auditory cortex as defined in control measurements with the same patients and in the experiments on healthy subjects. (authors) 17 refs., 4 figs.

Information processing in the hemisphere of the cerebellar cortex for control of wrist movement

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Tomatsu, Saeka; Ishikawa, Takahiro; Tsunoda, Yoshiaki; Lee, Jongho; Hoffman, Donna S.

2015-01-01

A region of cerebellar lobules V and VI makes strong loop connections with the primary motor (M1) and premotor (PM) cortical areas and is assumed to play essential roles in limb motor control. To examine its functional role, we compared the activities of its input, intermediate, and output elements, i.e., mossy fibers (MFs), Golgi cells (GoCs), and Purkinje cells (PCs), in three monkeys performing wrist movements in two different forearm postures. The results revealed distinct steps of information processing. First, MF activities displayed temporal and directional properties that were remarkably similar to those of M1/PM neurons, suggesting that MFs relay near copies of outputs from these motor areas. Second, all GoCs had a stereotyped pattern of activity independent of movement direction or forearm posture. Instead, GoC activity resembled an average of all MF activities. Therefore, inhibitory GoCs appear to provide a filtering function that passes only prominently modulated MF inputs to granule cells. Third, PCs displayed highly complex spatiotemporal patterns of activity, with coordinate frames distinct from those of MF inputs and directional tuning that changed abruptly before movement onset. The complexity of PC activities may reflect rapidly changing properties of the peripheral motor apparatus during movement. Overall, the cerebellar cortex appears to transform a representation of outputs from M1/PM into different movement representations in a posture-dependent manner and could work as part of a forward model that predicts the state of the peripheral motor apparatus. PMID:26467515

Glial tumors in brodmann area 6: spread pattern and relationships to motor areas.

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Shah, Komal B; Hayman, L Anne; Chavali, Lakshmi S; Hamilton, Jackson D; Prabhu, Sujit S; Wangaryattawanich, Pattana; Kumar, Vinodh A; Kumar, Ashok J

2015-01-01

The posterior frontal lobe of the brain houses Brodmann area 4, which is the primary motor cortex, and Brodmann area 6, which consists of the supplementary motor area on the medial portion of the hemisphere and the premotor cortex on the lateral portion. In this area, safe resection is dependent on accurate localization of the motor cortex and the central sulcus, which can usually be achieved by using thin-section imaging and confirmed by using other techniques. The most reliable anatomic landmarks are the "hand knob" area and the marginal ramus of the cingulate sulcus. Postoperatively, motor deficits can occur not only because of injury to primary motor cortex but also because of injury to the supplementary motor area. Unlike motor cortex injury, the supplementary motor area syndrome is transient, if it occurs at all. On the lateral hemisphere, motor and language deficits can also occur because of premotor cortex injury, but a dense motor deficit would indicate subcortical injury to the corticospinal tract. The close relationship of the subcortical motor fibers and premotor cortex is illustrated. In contrast to the more constant landmarks of the central sulcus and marginal ramus, which aid in preoperative localization, the variable interruptions in the precentral and cingulate sulci of the posterior frontal lobe seem to provide "cortical bridges" for spread of infiltrating gliomas. (©)RSNA, 2015.

The Effects of Context and Attention on Spiking Activity in Human Early Visual Cortex.

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Self, Matthew W; Peters, Judith C; Possel, Jessy K; Reithler, Joel; Goebel, Rainer; Ris, Peterjan; Jeurissen, Danique; Reddy, Leila; Claus, Steven; Baayen, Johannes C; Roelfsema, Pieter R

2016-03-01

Here we report the first quantitative analysis of spiking activity in human early visual cortex. We recorded multi-unit activity from two electrodes in area V2/V3 of a human patient implanted with depth electrodes as part of her treatment for epilepsy. We observed well-localized multi-unit receptive fields with tunings for contrast, orientation, spatial frequency, and size, similar to those reported in the macaque. We also observed pronounced gamma oscillations in the local-field potential that could be used to estimate the underlying spiking response properties. Spiking responses were modulated by visual context and attention. We observed orientation-tuned surround suppression: responses were suppressed by image regions with a uniform orientation and enhanced by orientation contrast. Additionally, responses were enhanced on regions that perceptually segregated from the background, indicating that neurons in the human visual cortex are sensitive to figure-ground structure. Spiking responses were also modulated by object-based attention. When the patient mentally traced a curve through the neurons' receptive fields, the accompanying shift of attention enhanced neuronal activity. These results demonstrate that the tuning properties of cells in the human early visual cortex are similar to those in the macaque and that responses can be modulated by both contextual factors and behavioral relevance. Our results, therefore, imply that the macaque visual system is an excellent model for the human visual cortex.

The Effects of Context and Attention on Spiking Activity in Human Early Visual Cortex.

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Matthew W Self

2016-03-01

Full Text Available Here we report the first quantitative analysis of spiking activity in human early visual cortex. We recorded multi-unit activity from two electrodes in area V2/V3 of a human patient implanted with depth electrodes as part of her treatment for epilepsy. We observed well-localized multi-unit receptive fields with tunings for contrast, orientation, spatial frequency, and size, similar to those reported in the macaque. We also observed pronounced gamma oscillations in the local-field potential that could be used to estimate the underlying spiking response properties. Spiking responses were modulated by visual context and attention. We observed orientation-tuned surround suppression: responses were suppressed by image regions with a uniform orientation and enhanced by orientation contrast. Additionally, responses were enhanced on regions that perceptually segregated from the background, indicating that neurons in the human visual cortex are sensitive to figure-ground structure. Spiking responses were also modulated by object-based attention. When the patient mentally traced a curve through the neurons' receptive fields, the accompanying shift of attention enhanced neuronal activity. These results demonstrate that the tuning properties of cells in the human early visual cortex are similar to those in the macaque and that responses can be modulated by both contextual factors and behavioral relevance. Our results, therefore, imply that the macaque visual system is an excellent model for the human visual cortex.

Meditation reduces pain-related neural activity in the anterior cingulate cortex, insula, secondary somatosensory cortex, and thalamus

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Nakata, Hiroki; Sakamoto, Kiwako; Kakigi, Ryusuke

2014-01-01

Recent studies have shown that meditation inhibits or relieves pain perception. To clarify the underlying mechanisms for this phenomenon, neuroimaging methods, such as functional magnetic resonance imaging, and neurophysiological methods, such as magnetoencephalography and electroencephalography, have been used. However, it has been difficult to interpret the results, because there is some paradoxical evidence. For example, some studies reported increased neural responses to pain stimulation during meditation in the anterior cingulate cortex (ACC) and insula, whereas others showed a decrease in these regions. There have been inconsistent findings to date. Moreover, in general, since the activities of the ACC and insula are correlated with pain perception, the increase in neural activities during meditation would be related to the enhancement of pain perception rather than its reduction. These contradictions might directly contribute to the ‘mystery of meditation.’ In this review, we presented previous findings for brain regions during meditation and the anatomical changes that occurred in the brain with long-term meditation training. We then discussed the findings of previous studies that examined pain-related neural activity during meditation. We also described the brain mechanisms responsible for pain relief during meditation, and possible reasons for paradoxical evidence among previous studies. By thoroughly overviewing previous findings, we hypothesized that meditation reduces pain-related neural activity in the ACC, insula, secondary somatosensory cortex, and thalamus. We suggest that the characteristics of the modulation of this activity may depend on the kind of meditation and/or number of years of experience of meditation, which were associated with paradoxical findings among previous studies that investigated pain-related neural activities during meditation. PMID:25566158

Chemosensory Learning in the Cortex

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Edmund eRolls

2011-09-01

Full Text Available Taste is a primary reinforcer. Olfactory-taste and visual-taste association learning takes place in the primate including human orbitofrontal cortex to build representations of flavour. Rapid reversal of this learning can occur using a rule-based learning system that can be reset when an expected taste or flavour reward is not obtained, that is by negative reward prediction error, to which a population of neurons in the orbitofrontal cortex responds. The representation in the orbitofrontal cortex but not the primary taste or olfactory cortex is of the reward value of the visual / olfactory / taste / input as shown by devaluation experiments in which food is fed to satiety, and by correlations with the activations with subjective pleasantness ratings in humans. Sensory-specific satiety for taste, olfactory, visual, and oral somatosensory inputs produced by feeding a particular food to satiety are implemented it is proposed by medium-term synaptic adaptation in the orbitofrontal cortex. Cognitive factors, including word-level descriptions, modulate the representation of the reward value of food in the orbitofrontal cortex, and this effect is learned it is proposed by associative modification of top-down synapses onto neurons activated by bottom-up taste and olfactory inputs when both are active in the orbitofrontal cortex. A similar associative synaptic learning process is proposed to be part of the mechanism for the top-down attentional control to the reward value vs the sensory properties such as intensity of taste and olfactory inputs in the orbitofrontal cortex, as part of a biased activation theory of selective attention.

The human premotor oculomotor brainstem system - can it help to understand oculomotor symptoms in Huntington's disease?

NARCIS (Netherlands)

Rueb, U.; Heinsen, H.; Brunt, E. R.; Landwehrmeyer, B.; Den Dunnen, W. F. A.; Gierga, K.; Deller, T.

Recent progress in oculomotor research has enabled new insights into the functional neuroanatomy of the human premotor oculomotor brainstem network. In the present review, we provide an overview of its functional neuroanatomy and summarize the broad range of oculomotor dysfunctions that may occur in

Motor Cortex Activity During Functional Motor Skills: An fNIRS Study.

Science.gov (United States)

Nishiyori, Ryota; Bisconti, Silvia; Ulrich, Beverly

2016-01-01

Assessments of brain activity during motor task performance have been limited to fine motor movements due to technological constraints presented by traditional neuroimaging techniques, such as functional magnetic resonance imaging. Functional near-infrared spectroscopy (fNIRS) offers a promising method by which to overcome these constraints and investigate motor performance of functional motor tasks. The current study used fNIRS to quantify hemodynamic responses within the primary motor cortex in twelve healthy adults as they performed unimanual right, unimanual left, and bimanual reaching, and stepping in place. Results revealed that during both unimanual reaching tasks, the contralateral hemisphere showed significant activation in channels located approximately 3 cm medial to the C3 (for right-hand reach) and C4 (for left-hand reach) landmarks. Bimanual reaching and stepping showed activation in similar channels, which were located bilaterally across the primary motor cortex. The medial channels, surrounding Cz, showed significantly higher activations during stepping when compared to bimanual reaching. Our results extend the viability of fNIRS to study motor function and build a foundation for future investigation of motor development in infants during nascent functional behaviors and monitor how they may change with age or practice.

The changes of regional cerebral blood flow: successful pain relief of intractable CRPS type II patients by motor cortex stimulation

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Jung, J. A.; Son, H. S.; Kim, S. H.; Jung, S. G [The Catholic University of Korea, Seoul (Korea, Republic of)

2004-07-01

Authors report the effectiveness of MCS in extraordinarily extended pain due to intractable CRPS type II and rCBF study result for mechanism of pain control by MCS. A 43-year-old male presented severe spontaneous burning pain in his left hand and forearm and allodynia over the left arm and left hemibody. Authors planned MCS as a neuromodulation therapy for this intractable peripheral neuropathic pain patient because further neurodestructive procedure did not work anymore and have a potential risk of further aggrevation of neuopathic pain. We performed baseline and stimulation brain perfusion SPECT using 20 mCi of Tc-99m ECD. The baseline CBD studies were done with stimulator 'off' state and stimulation studies were done after stimulator 'on' with satisfactory pain relief. For the stimulation study, the radioisotope was injected immediately after pain-relief and the images were taken about 50 minutes after injection of radioisotope. In resting rCBF in the patient was compared with normal control datas, we found significant increase in rCBF in the bilateral prefrontal cortex, right dorsolateral prefrontal cortex, right superior temporal gyrus, left temporooccipital area. When rCBF datas obtained after alleviation of pain with stimulator 'on' . there were significant increase in rCBF in bilateral prefrontal cortex and left temporoocipital area. After subtraction of ECD SPECT, we found significant increase in rCBF in the right premotor and supplementary motor cortex left sensorimotor cortex, right cingulated cortex, right posterior insular cortex, right anterior limb of internal capsule. left orbitofrontal cortex and right pyramidal tract in cerebral peduncle. Authors report exellent pain control by MCS in a case of severe CRPS type II with hemibody involvement and regional cerebral blood flow changes according to successful pain control.

The changes of regional cerebral blood flow: successful pain relief of intractable CRPS type II patients by motor cortex stimulation

International Nuclear Information System (INIS)

Jung, J. A.; Son, H. S.; Kim, S. H.; Jung, S. G

2004-01-01

Authors report the effectiveness of MCS in extraordinarily extended pain due to intractable CRPS type II and rCBF study result for mechanism of pain control by MCS. A 43-year-old male presented severe spontaneous burning pain in his left hand and forearm and allodynia over the left arm and left hemibody. Authors planned MCS as a neuromodulation therapy for this intractable peripheral neuropathic pain patient because further neurodestructive procedure did not work anymore and have a potential risk of further aggrevation of neuopathic pain. We performed baseline and stimulation brain perfusion SPECT using 20 mCi of Tc-99m ECD. The baseline CBD studies were done with stimulator 'off' state and stimulation studies were done after stimulator 'on' with satisfactory pain relief. For the stimulation study, the radioisotope was injected immediately after pain-relief and the images were taken about 50 minutes after injection of radioisotope. In resting rCBF in the patient was compared with normal control datas, we found significant increase in rCBF in the bilateral prefrontal cortex, right dorsolateral prefrontal cortex, right superior temporal gyrus, left temporooccipital area. When rCBF datas obtained after alleviation of pain with stimulator 'on' . there were significant increase in rCBF in bilateral prefrontal cortex and left temporoocipital area. After subtraction of ECD SPECT, we found significant increase in rCBF in the right premotor and supplementary motor cortex left sensorimotor cortex, right cingulated cortex, right posterior insular cortex, right anterior limb of internal capsule. left orbitofrontal cortex and right pyramidal tract in cerebral peduncle. Authors report exellent pain control by MCS in a case of severe CRPS type II with hemibody involvement and regional cerebral blood flow changes according to successful pain control

Contribution of LFP dynamics to single-neuron spiking variability in motor cortex during movement execution

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Rule, Michael E.; Vargas-Irwin, Carlos; Donoghue, John P.; Truccolo, Wilson

2015-01-01

Understanding the sources of variability in single-neuron spiking responses is an important open problem for the theory of neural coding. This variability is thought to result primarily from spontaneous collective dynamics in neuronal networks. Here, we investigate how well collective dynamics reflected in motor cortex local field potentials (LFPs) can account for spiking variability during motor behavior. Neural activity was recorded via microelectrode arrays implanted in ventral and dorsal premotor and primary motor cortices of non-human primates performing naturalistic 3-D reaching and grasping actions. Point process models were used to quantify how well LFP features accounted for spiking variability not explained by the measured 3-D reach and grasp kinematics. LFP features included the instantaneous magnitude, phase and analytic-signal components of narrow band-pass filtered (δ,θ,α,β) LFPs, and analytic signal and amplitude envelope features in higher-frequency bands. Multiband LFP features predicted single-neuron spiking (1ms resolution) with substantial accuracy as assessed via ROC analysis. Notably, however, models including both LFP and kinematics features displayed marginal improvement over kinematics-only models. Furthermore, the small predictive information added by LFP features to kinematic models was redundant to information available in fast-timescale (spiking history. Overall, information in multiband LFP features, although predictive of single-neuron spiking during movement execution, was redundant to information available in movement parameters and spiking history. Our findings suggest that, during movement execution, collective dynamics reflected in motor cortex LFPs primarily relate to sensorimotor processes directly controlling movement output, adding little explanatory power to variability not accounted by movement parameters. PMID:26157365

Effect of visual feedback on brain activation during motor tasks: an FMRI study.

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Noble, Jeremy W; Eng, Janice J; Boyd, Lara A

2013-07-01

This study examined the effect of visual feedback and force level on the neural mechanisms responsible for the performance of a motor task. We used a voxel-wise fMRI approach to determine the effect of visual feedback (with and without) during a grip force task at 35% and 70% of maximum voluntary contraction. Two areas (contralateral rostral premotor cortex and putamen) displayed an interaction between force and feedback conditions. When the main effect of feedback condition was analyzed, higher activation when visual feedback was available was found in 22 of the 24 active brain areas, while the two other regions (contralateral lingual gyrus and ipsilateral precuneus) showed greater levels of activity when no visual feedback was available. The results suggest that there is a potentially confounding influence of visual feedback on brain activation during a motor task, and for some regions, this is dependent on the level of force applied.

Infralimbic cortex Rho-kinase inhibition causes antidepressant-like activity in rats.

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Inan, Salim Yalcin; Soner, Burak Cem; Sahin, Ayse Saide

2015-03-03

Depression is one of the most common psychiatric disorders in the world; however, its mechanisms remain unclear. Recently, a new signal-transduction pathway, namely Rho/Rho-kinase signalling, has been suggested to be involved in diverse cellular events in the central nervous system; such as epilepsy, anxiety-related behaviors, regulation of dendritic and axonal morphology, antinociception, subarachnoid haemorrhage, spinal cord injury and amyotrophic lateral sclerosis. However there is no evidence showing the involvement of Rho-kinase pathway in depression. In addition, the infralimbic cortex, rodent equivalent to subgenual cingulate cortex has been shown to be responsible for emotional responses. Thus, in the present study, intracranial guide cannulae were stereotaxically implanted bilaterally into the infralimbic cortex, and the effects of repeated microinjections of a Rho-kinase (ROCK) inhibitor Y-27632 (10 nmol) were investigated in rats. Y-27632 significantly decreased immobility time and increased swimming and climbing behaviors when compared to fluoxetine (10 μg) and saline groups in the forced swim test. In addition, Y-27632 treatment did not affect spontaneous locomotor activity and forelimb use in the open-field and cylinder tests respectively; but it enhanced limb placing accuracy in the ladder rung walking test. Our results suggest that Y-27632 could be a potentially active antidepressant agent. Copyright © 2014 Elsevier Inc. All rights reserved.

P1-27: Localizing Regions Activated by Surface Gloss in Macaque Visual Cortex by fMRI

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Gouki Okazawa

2012-10-01

Full Text Available Surface properties of objects such as gloss provide important information about the states or materials of objects in our visual experiences. Previous studies have shown that there are cortical regions responding to shapes, colors, faces etc. in the macaque visual cortex. However, we still lack the information about where the surface properties are processed in the macaque visual cortex. In this study, we examined whether there are regions activated by surface gloss, an important surface property, in the macaque visual cortex by using functional magnetic resonance imaging (fMRI. We trained two monkeys to fixate on a small spot on the screen in MRI scanner, while the images of glossy and matte objects were presented. As a control condition for low-level image features, such as spatial frequency or luminance contrast, we generated scrambled images by locally randomizing the luminance phases of images using wavelet filters. By contrasting the responses to glossy images to those to matte and scrambled images, we found the activation in wide regions along the ventral visual pathway including V1, V2, V3, V4, and the posterior part of the inferior temporal (IT cortex. In one monkey, we also found the activations in the central part of IT cortex. In another control experiment, we manipulated the image contrasts and found that the responses in these regions cannot be explained simply by the image contrasts. These results suggest that surface gloss is processed along the ventral pathway and, in the IT cortex there are distinct regions processing surface gloss.

Neuroimaging in pre-motor Parkinson's disease

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Thomas R. Barber

2017-01-01

Full Text Available The process of neurodegeneration in Parkinson's disease begins long before the onset of clinical motor symptoms, resulting in substantial cell loss by the time a diagnosis can be made. The period between the onset of neurodegeneration and the development of motoric disease would be the ideal time to intervene with disease modifying therapies. This pre-motor phase can last many years, but the lack of a specific clinical phenotype means that objective biomarkers are needed to reliably detect prodromal disease. In recent years, recognition that patients with REM sleep behaviour disorder (RBD are at particularly high risk of future parkinsonism has enabled the development of large prodromal cohorts in which to investigate novel biomarkers, and neuroimaging has generated some of the most promising results to date. Here we review investigations undertaken in RBD and other pre-clinical cohorts, including modalities that are well established in clinical Parkinson's as well as novel imaging methods. Techniques such as high resolution MRI of the substantia nigra and functional imaging of Parkinsonian brain networks have great potential to facilitate early diagnosis. Further longitudinal studies will establish their true value in quantifying prodromal neurodegeneration and predicting future Parkinson's.

Sensorimotor cortical activity in patients with complete spinal cord injury: a functional magnetic resonance imaging study.

Science.gov (United States)

Sabbah, P; de, Schonen S; Leveque, C; Gay, S; Pfefer, F; Nioche, C; Sarrazin, J L; Barouti, H; Tadie, M; Cordoliani, Y S

2002-01-01

Residual activation of the cortex was investigated in nine patients with complete spinal cord injury between T6 and L1 by functional magnetic resonance imaging (fMRI). Brain activations were recorded under four conditions: (1) a patient attempting to move his toes with flexion-extension, (2) a patient imagining the same movement, (3) passive proprio-somesthesic stimulation of the big toes without visual control, and (4) passive proprio-somesthesic stimulation of the big toes with visual control by the patient. Passive proprio-somesthesic stimulation of the toes generated activation posterior to the central sulcus in the three patients who also showed a somesthesic evoked potential response to somesthesic stimulation. When performed under visual control, activations were observed in two more patients. In all patients, activations were found in the cortical areas involved in motor control (i.e., primary sensorimotor cortex, premotor regions and supplementary motor area [SMA]) during attempts to move or mental imagery of these tasks. It is concluded that even several years after injury with some local cortical reorganization, activation of lower limb cortical networks can be generated either by the attempt to move, the mental evocation of the action, or the visual feedback of a passive proprio-somesthesic stimulation.

Evolution of posterior parietal cortex and parietal-frontal networks for specific actions in primates.

Science.gov (United States)

Kaas, Jon H; Stepniewska, Iwona

2016-02-15

Posterior parietal cortex (PPC) is an extensive region of the human brain that develops relatively late and is proportionally large compared with that of monkeys and prosimian primates. Our ongoing comparative studies have led to several conclusions about the evolution of this posterior parietal region. In early placental mammals, PPC likely was a small multisensory region much like PPC of extant rodents and tree shrews. In early primates, PPC likely resembled that of prosimian galagos, in which caudal PPC (PPCc) is visual and rostral PPC (PPCr) has eight or more multisensory domains where electrical stimulation evokes different complex motor behaviors, including reaching, hand-to-mouth, looking, protecting the face or body, and grasping. These evoked behaviors depend on connections with functionally matched domains in premotor cortex (PMC) and motor cortex (M1). Domains in each region compete with each other, and a serial arrangement of domains allows different factors to influence motor outcomes successively. Similar arrangements of domains have been retained in New and Old World monkeys, and humans appear to have at least some of these domains. The great expansion and prolonged development of PPC in humans suggest the addition of functionally distinct territories. We propose that, across primates, PMC and M1 domains are second and third levels in a number of parallel, interacting networks for mediating and selecting one type of action over others. © 2015 Wiley Periodicals, Inc.

Predicting Treatment Outcomes from Prefrontal Cortex Activation for Self-Harming Patients with Borderline Personality Disorder: A Preliminary Study

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Anthony Charles Ruocco

2016-05-01

Full Text Available Self-harm is a potentially lethal symptom of borderline personality disorder (BPD that often improves with dialectical behavior therapy (DBT. While DBT is effective for reducing self-harm in many patients with BPD, a small but significant number of patients either does not improve in treatment or ends treatment prematurely. Accordingly, it is crucial to identify factors that may prospectively predict which patients are most likely to benefit from and remain in treatment. In the present preliminary study, twenty-nine actively self-harming patients with BPD completed brain-imaging procedures probing activation of the prefrontal cortex during impulse control prior to beginning DBT and after seven months of treatment. Patients that reduced their frequency of self-harm the most over treatment displayed lower levels of neural activation in the bilateral dorsolateral prefrontal cortex prior to beginning treatment, and they showed the greatest increases in activity within this region after seven months of treatment. Prior to starting DBT, treatment non-completers demonstrated greater activation than treatment-completers in the medial prefrontal cortex and right inferior frontal gyrus. Reductions in self-harm over the treatment period were associated with increases in activity in right dorsolateral prefrontal cortex even after accounting for improvements in depression, mania, and BPD symptom severity. These findings suggest that pre-treatment patterns of activation in the prefrontal cortex underlying impulse control may be prospectively associated with improvements in self-harm and treatment attrition for patients with BPD treated with DBT.

Antimicrobial and antioxidant activities of Cortex Magnoliae Officinalis and some other medicinal plants commonly used in South-East Asia

Science.gov (United States)

Chan, Lai Wah; Cheah, Emily LC; Saw, Constance LL; Weng, Wanyu; Heng, Paul WS

2008-01-01

Background Eight medicinal plants were tested for their antimicrobial and antioxidant activities. Different extraction methods were also tested for their effects on the bioactivities of the medicinal plants. Methods Eight plants, namely Herba Polygonis Hydropiperis (Laliaocao), Folium Murraya Koenigii (Jialiye), Rhizoma Arachis Hypogea (Huashenggen), Herba Houttuyniae (Yuxingcao), Epipremnum pinnatum (Pashulong), Rhizoma Typhonium Flagelliforme (Laoshuyu), Cortex Magnoliae Officinalis (Houpo) and Rhizoma Imperatae (Baimaogen) were investigated for their potential antimicrobial and antioxidant properties. Results Extracts of Cortex Magnoliae Officinalis had the strongest activities against M. Smegmatis, C. albicans, B. subtilis and S. aureus. Boiled extracts of Cortex Magnoliae Officinalis, Folium Murraya Koenigii, Herba Polygonis Hydropiperis and Herba Houttuyniae demonstrated greater antioxidant activities than other tested medicinal plants. Conclusion Among the eight tested medicinal plants, Cortex Magnoliae Officinalis showed the highest antimicrobial and antioxidant activities. Different methods of extraction yield different spectra of bioactivities. PMID:19038060

GABA(A) receptors in visual and auditory cortex and neural activity changes during basic visual stimulation.

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Qin, Pengmin; Duncan, Niall W; Wiebking, Christine; Gravel, Paul; Lyttelton, Oliver; Hayes, Dave J; Verhaeghe, Jeroen; Kostikov, Alexey; Schirrmacher, Ralf; Reader, Andrew J; Northoff, Georg

2012-01-01

Recent imaging studies have demonstrated that levels of resting γ-aminobutyric acid (GABA) in the visual cortex predict the degree of stimulus-induced activity in the same region. These studies have used the presentation of discrete visual stimulus; the change from closed eyes to open also represents a simple visual stimulus, however, and has been shown to induce changes in local brain activity and in functional connectivity between regions. We thus aimed to investigate the role of the GABA system, specifically GABA(A) receptors, in the changes in brain activity between the eyes closed (EC) and eyes open (EO) state in order to provide detail at the receptor level to complement previous studies of GABA concentrations. We conducted an fMRI study involving two different modes of the change from EC to EO: an EO and EC block design, allowing the modeling of the haemodynamic response, followed by longer periods of EC and EO to allow the measuring of functional connectivity. The same subjects also underwent [(18)F]Flumazenil PET to measure GABA(A) receptor binding potentials. It was demonstrated that the local-to-global ratio of GABA(A) receptor binding potential in the visual cortex predicted the degree of changes in neural activity from EC to EO. This same relationship was also shown in the auditory cortex. Furthermore, the local-to-global ratio of GABA(A) receptor binding potential in the visual cortex also predicted the change in functional connectivity between the visual and auditory cortex from EC to EO. These findings contribute to our understanding of the role of GABA(A) receptors in stimulus-induced neural activity in local regions and in inter-regional functional connectivity.

Premotor spinal network with balanced excitation and inhibition during motor patterns has high resilience to structural division

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Petersen, Peter C; Vestergaard, Mikkel; Reveles Jensen, Kristian

2014-01-01

Direct measurements of synaptic inhibition (I) and excitation (E) to spinal motoneurons can provide an important insight into the organization of premotor networks. Such measurements of flexor motoneurons participating in motor patterns in turtles have recently demonstrated strong concurrent E...

Bold-functional MRI study of the abnormal cortex and the relationship between the inpairment of vision and the decreased activation of the visual cortex in anisometropic amblyopia

International Nuclear Information System (INIS)

Wang Jian; Li Chuanming; Zhou Yang; Xie Bing; Yu Qiongwu; Wang Hui; Qiu Mingguo; Weng Xuchu

2006-01-01

Objective: To assess the activation changes on Brodmann areas 17, 18 and 19 in anisometropic amblyopia and compare the features of the cortex activations before and after refractive correction on amblyopic eyes. Methods: Bold-fMRI technique on 1.5 T Simens Sonata MRI and the blocks designation mode was used. The visual stimulation task was a black and white checkerboard with frequencies of 1 cycle/degree and 8 Hz. The baseline stimulus is a white cross-line at the center of the screen with black background. No other light or influence was allowed in the scanning room. The distance between the eyes and screen was 0.6 m. The experimental group included 10 anisometropic amblyopes. TSE and EPI sequence were used for the anatomical and functional data acquisitions. For experimental group, the activation areas of the visual cortex on both eyes were consequently measured before and after refractive correction. All data were analyzed online with t-test and offline with AFNI software. The threshold value was set to 0.001. During data processing, motion correction and three-dimensional smooth were used in all data. The time-signal intensity curves and the functional images were obtained. After Talairach coordinated the function images of every one, the activation areas were measured in Brodmann areas 17, 18 and 19. The SPSS 12.0 software was used for statistic analysis. The difference of the cortical activations of amblyopic eyes before and after refractive correction was analyzed. The cortical activations of amblyopic eyes and the fellow eyes after refractive correction were compared. The visual acuity of the amblyopia eyes was measured. And the correlation between the lesion of cortical activation and visual acuity was analyzed. Results: It was found that the cortex was activated obviously in the calcarine cortex around, occipital lobe, LGN and temporal lobe. The activation areas of amblyopic eyes was (3.7±0.4) x 10 4 voxels, and (4.1±0.5 ) x 10 4 voxets after corrected

Study of physiology of visual cortex activated by rotating grating with functional MRI

International Nuclear Information System (INIS)

Liang Ping; Shao Qing; Zhang Zhiqiang; Lu Guangming

2004-01-01

Objective: To research the physiology of visual cortex activated by rotating grating with functional-MRI (fMRI), and to identify the components of the activation. Methods: Functional MRI was performed in 9 healthy volunteers by using GRE-EPI sequences on a 1.5 T MR scanner. In the block designing, rotating grating, static grating, and luminance were plotted as task states, while static grating, luminance, and darkness were set as control states. The stimuli tasks included six steps. Imaging processing and statistical analysis was carried out off-line using SPM99 in single-subject method. Results: Some respective areas of visual cortex were activated by the various stimuli information supplied by rotating grating. The strong activation in the middle of occipital lobe located at primary vision area was related to the stimuli of white luminance. Its average maximum points were at 13, -98, -2 and 11, -100, -41 The bilateral activations of Brodmann 19th area located at MT area were related to visual motion perception. Its average maximum points were at 46, -72, -2 and -44, -74, 0. The mild activation in the middle of occipital lobe was related to form perception. Its average maximum points were at -12, -98, -6 and -16, -96, -6. Conclusion: The plotting of control state is important in bock design. The effective visual information of rotating grating includes components of luminance, visual motion perception, and form perception. FMRI has potential as a tool for studying the basic physiology of visual cortex. (authors)

Activation of cannabinoid system in anterior cingulate cortex and orbitofrontal cortex modulates cost-benefit decision making.

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Khani, Abbas; Kermani, Mojtaba; Hesam, Soghra; Haghparast, Abbas; Argandoña, Enrike G; Rainer, Gregor

2015-06-01

Despite the evidence for altered decision making in cannabis abusers, the role of the cannabinoid system in decision-making circuits has not been studied. Here, we examined the effects of cannabinoid modulation during cost-benefit decision making in the anterior cingulate cortex (ACC) and orbitofrontal cortex (OFC), key brain areas involved in decision making. We trained different groups of rats in a delay-based and an effort-based form of cost-benefit T-maze decision-making task. During test days, the rats received local injections of either vehicle or ACEA, a cannabinoid type-1 receptor (CB1R) agonist in the ACC or OFC. We measured spontaneous locomotor activity following the same treatments and characterized CB1Rs localization on different neuronal populations within these regions using immunohistochemistry. We showed that CB1R activation in the ACC impaired decision making such that rats were less willing to invest physical effort to gain high reward. Similarly, CB1R activation in the OFC induced impulsive pattern of choice such that rats preferred small immediate rewards to large delayed rewards. Control tasks ensured that the effects were specific for differential cost-benefit tasks. Furthermore, we characterized widespread colocalizations of CB1Rs on GABAergic axonal ends but few colocalizations on glutamatergic, dopaminergic, and serotonergic neuronal ends. These results provide first direct evidence that the cannabinoid system plays a critical role in regulating cost-benefit decision making in the ACC and OFC and implicate cannabinoid modulation of synaptic ends of predominantly interneurons and to a lesser degree other neuronal populations in these two frontal regions.

Neuropeptide S overcomes short term memory deficit induced by sleep restriction by increasing prefrontal cortex activity.

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Thomasson, Julien; Canini, Frédéric; Poly-Thomasson, Betty; Trousselard, Marion; Granon, Sylvie; Chauveau, Frédéric

2017-12-01

Sleep restriction (SR) impairs short term memory (STM) that might be related to different processes. Neuropeptide S (NPS), an endogenous neuropeptide that improves short term memory, activates arousal and decreases anxiety is likely to counteract the SR-induced impairment of STM. The objective of the present study was to find common cerebral pathways in sleep restriction and NPS action in order to ultimately antagonize SR effect on memory. The STM was assessed using a spontaneous spatial alternation task in a T-maze. C57-Bl/6J male mice were distributed in 4 groups according to treatment (0.1nmol of NPS or vehicle intracerebroventricular injection) and to 20h-SR. Immediately after behavioural testing, regional c-fos immunohistochemistry was performed and used as a neural activation marker for spatial short term memory (prefrontal cortex, dorsal hippocampus) and emotional reactivity (basolateral amygdala and ventral hippocampus). Anxiety-like behaviour was assessed using elevated-plus maze task. Results showed that SR impaired short term memory performance and decreased neuronal activation in cingular cortex.NPS injection overcame SR-induced STM deficits and increased neuronal activation in infralimbic cortex. SR spared anxiety-like behavior in the elevated-plus maze. Neural activation in basolateral nucleus of amygdala and ventral hippocampus were not changed after SR.In conclusion, the present study shows that NPS overcomes SR-induced STM deficits by increasing prefrontal cortex activation independently of anxiety-like behaviour. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Prefrontal cortex and somatosensory cortex in tactile crossmodal association: an independent component analysis of ERP recordings.

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Yixuan Ku

2007-08-01

Full Text Available Our previous studies on scalp-recorded event-related potentials (ERPs showed that somatosensory N140 evoked by a tactile vibration in working memory tasks was enhanced when human subjects expected a coming visual stimulus that had been paired with the tactile stimulus. The results suggested that such enhancement represented the cortical activities involved in tactile-visual crossmodal association. In the present study, we further hypothesized that the enhancement represented the neural activities in somatosensory and frontal cortices in the crossmodal association. By applying independent component analysis (ICA to the ERP data, we found independent components (ICs located in the medial prefrontal cortex (around the anterior cingulate cortex, ACC and the primary somatosensory cortex (SI. The activity represented by the IC in SI cortex showed enhancement in expectation of the visual stimulus. Such differential activity thus suggested the participation of SI cortex in the task-related crossmodal association. Further, the coherence analysis and the Granger causality spectral analysis of the ICs showed that SI cortex appeared to cooperate with ACC in attention and perception of the tactile stimulus in crossmodal association. The results of our study support with new evidence an important idea in cortical neurophysiology: higher cognitive operations develop from the modality-specific sensory cortices (in the present study, SI cortex that are involved in sensation and perception of various stimuli.

Motor activation in SPG4-linked hereditary spastic paraplegia

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Scheuer, KH; Nielsen, JE; Krabbe, Katja

2006-01-01

OBJECTIVE: The aim of this study was to investigate the extent of motor cortical functional reorganisation in patients with SPG4-linked hereditary spastic paraplegia by exploring cortical motor activation related to movements of clinically affected (lower) and unaffected (upper) limbs. METHODS......: Thirteen patients and 13 normal controls matched for age, gender and handedness underwent O15-labelled water positron emission tomography during (1) right ankle flexion-extension, (2) right shoulder flexion-extension and (3) rest. Within-group comparisons of movement vs. rest (simple main effects......, the supplementary motor areas and the right premotor cortex compared to controls. CONCLUSIONS: Motor cortical reorganisation may explain this result, but as no significant differences were recognised in the motor response of the unaffected limb, differences in functional demands should also be considered...

Activation of the Infralimbic Cortex in a Fear Context Enhances Extinction Learning

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Thompson, Brittany M.; Baratta, Michael V.; Biedenkapp, Joseph C.; Rudy, Jerry W.; Watkins, Linda R.; Maier, Steven F.

2010-01-01

Activation of the infralimbic region (IL) of the medial prefrontal cortex (mPFC) reduces conditioned fear in a variety of situations, and the IL is thought to play an important role in the extinction of conditioned fear. Here we report a series of experiments using contextual fear conditioning in which the IL is activated with the GABAa antagonist…

Antimicrobial and antioxidant activities of Cortex Magnoliae Officinalis and some other medicinal plants commonly used in South-East Asia

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Weng Wanyu

2008-11-01

Full Text Available Abstract Background Eight medicinal plants were tested for their antimicrobial and antioxidant activities. Different extraction methods were also tested for their effects on the bioactivities of the medicinal plants. Methods Eight plants, namely Herba Polygonis Hydropiperis (Laliaocao, Folium Murraya Koenigii (Jialiye, Rhizoma Arachis Hypogea (Huashenggen, Herba Houttuyniae (Yuxingcao, Epipremnum pinnatum (Pashulong, Rhizoma Typhonium Flagelliforme (Laoshuyu, Cortex Magnoliae Officinalis (Houpo and Rhizoma Imperatae (Baimaogen were investigated for their potential antimicrobial and antioxidant properties. Results Extracts of Cortex Magnoliae Officinalis had the strongest activities against M. Smegmatis, C. albicans, B. subtilis and S. aureus. Boiled extracts of Cortex Magnoliae Officinalis, Folium Murraya Koenigii, Herba Polygonis Hydropiperis and Herba Houttuyniae demonstrated greater antioxidant activities than other tested medicinal plants. Conclusion Among the eight tested medicinal plants, Cortex Magnoliae Officinalis showed the highest antimicrobial and antioxidant activities. Different methods of extraction yield different spectra of bioactivities.

Progressive and widespread brain damage in ALS: MRI voxel-based morphometry and diffusion tensor imaging study.

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Senda, Joe; Kato, Shigenori; Kaga, Tomotsugu; Ito, Mizuki; Atsuta, Naoki; Nakamura, Tomohiko; Watanabe, Hirohisa; Tanaka, Fumiaki; Naganawa, Shinji; Sobue, Gen

2011-01-01

We investigated 17 patients with sporadic amyotrophic lateral sclerosis (ALS) using voxel-based morphometry (VBM) and voxel-based analysis of diffusion tensor images (DTI) at baseline and after a six-month follow-up. Compared with 17 healthy controls, ALS patients at baseline showed only minimal white matter volume decreases in the inferior frontal gyrus but marked decreases in the gray matter of several regions, especially in the bilateral paracentral lobule of the premotor cortex. DTI revealed reduced fractional anisotropy in the bilateral corticospinal tracts, insula, ventrolateral premotor cortex, and parietal cortex. Increased mean diffusivity was noted bilaterally in the motor cortex, ventrolateral premotor cortex, insula, hippocampal formation, and temporal gyrus. At the six-month follow-up, ALS patients showed widespread volume decreases in gray matter, and DTI abnormalities extended mainly into the bilateral frontal lobes, while volume changes in the white matter remained minimal but more distinct. Our combined VBM and DTI techniques revealed extra-corticospinal tract neuronal degeneration mainly in the frontotemporal lobe of ALS patients. In particular, follow-up examinations in these patients showed that whole-brain DTI changes occurred predominantly in the regions of brain atrophy. These objective analyses can be used to assess the disease condition of the ALS brain.

Early 'visual' cortex activation correlates with superior verbal memory performance in the blind.

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Amedi, Amir; Raz, Noa; Pianka, Pazit; Malach, Rafael; Zohary, Ehud

2003-07-01

The visual cortex may be more modifiable than previously considered. Using functional magnetic resonance imaging (fMRI) in ten congenitally blind human participants, we found robust occipital activation during a verbal-memory task (in the absence of any sensory input), as well as during verb generation and Braille reading. We also found evidence for reorganization and specialization of the occipital cortex, along the anterior-posterior axis. Whereas anterior regions showed preference for Braille, posterior regions (including V1) showed preference for verbal-memory and verb generation (which both require memory of verbal material). No such occipital activation was found in sighted subjects. This difference between the groups was mirrored by superior performance of the blind in various verbal-memory tasks. Moreover, the magnitude of V1 activation during the verbal-memory condition was highly correlated with the blind individual's abilities in a variety of verbal-memory tests, suggesting that the additional occipital activation may have a functional role.

Neural correlates of hate.

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Semir Zeki

Full Text Available In this work, we address an important but unexplored topic, namely the neural correlates of hate. In a block-design fMRI study, we scanned 17 normal human subjects while they viewed the face of a person they hated and also faces of acquaintances for whom they had neutral feelings. A hate score was obtained for the object of hate for each subject and this was used as a covariate in a between-subject random effects analysis. Viewing a hated face resulted in increased activity in the medial frontal gyrus, right putamen, bilaterally in premotor cortex, in the frontal pole and bilaterally in the medial insula. We also found three areas where activation correlated linearly with the declared level of hatred, the right insula, right premotor cortex and the right fronto-medial gyrus. One area of deactivation was found in the right superior frontal gyrus. The study thus shows that there is a unique pattern of activity in the brain in the context of hate. Though distinct from the pattern of activity that correlates with romantic love, this pattern nevertheless shares two areas with the latter, namely the putamen and the insula.

Glutathione S-transferases in human renal cortex and neoplastic tissue: enzymatic activity, isoenzyme profile and immunohistochemical localization.

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Rodilla, V; Benzie, A A; Veitch, J M; Murray, G I; Rowe, J D; Hawksworth, G M

1998-05-01

1. Glutathione S-transferase (GST) activity in the cytosol of renal cortex and tumours from eight men and eight women was measured using 1-chloro-2,4-dinitrobenzene (CDNB) as a substrate. GST activities ranged from 685 to 2192 nmol/min/mg protein in cortex (median 1213) and from non-detectable (minimum 45) to 2424 nmol/min/mg protein in tumours (median 469). The activities in the tumours were lower than those in the normal cortices (p 0.05). 3. The age of the patients ranged from 42 to 81 years (median 62) and was not found to play a role in the levels of GST activity observed in cortex or in renal tumours from either sex. 4. Immunoblotting and immunohistochemical studies confirmed that GST-alpha was the predominant form expressed both in normal cortex and tumour and probably accounted for most of the GST activity present in these samples. GST-mu and GST-phi were expressed in both tumours and normal cortex and, while in some cases the level of expression in the cortices was higher than that found in the tumours, the reverse was also observed. Within the GST-mu class, GST M1/M2 was only detected in one sample (tumour), which showed the highest overall expression of GST-mu. GSTM3 was the predominant isoenzyme of the mu class in normal and tumour tissue, whereas GTM4 and GSTM5 were not detected. 5. These differences could have functional significance where xenobiotics or cytotoxic drugs are specific substrates for the different classes of GSTs.

Comparison of functional recovery of manual dexterity after unilateral spinal cord lesion or motor cortex lesion in adult macaque monkeys

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Florence eHoogewoud

2013-07-01

Full Text Available In relation to mechanisms involved in functional recovery of manual dexterity from cervical cord injury or from motor cortical injury, our goal was to determine whether the movements that characterize post-lesion functional recovery are comparable to original movement patterns or do monkeys adopt distinct strategies to compensate the deficits depending on the type of lesion? To this aim, data derived from earlier studies, using a skilled finger task (the modified Brinkman board from which pellets are retrieved from vertical or horizontal slots, in spinal cord and motor cortex injured monkeys were analyzed and compared. Twelve adult macaque monkeys were subjected to a hemi-section of the cervical cord (n=6 or to a unilateral excitotoxic lesion of the hand representation in the primary motor cortex (n=6. In addition, in each subgroup, one half of monkeys (n=3 were treated for 30 days with a function blocking antibody against the neurite growth inhibitory protein Nogo-A, while the other half (n=3 represented control animals. The motor deficits, and the extent and time course of functional recovery were assessed.For some of the parameters investigated (wrist angle for horizontal slots and movement types distribution for vertical slots after cervical injury; movement types distribution for horizontal slots after motor cortex lesion, post-lesion restoration of the original movement patterns (true recovery led to a quantitatively better functional recovery. In the motor cortex lesion groups, pharmacological reversible inactivation experiments showed that the peri-lesion territory of the primary motor cortex or re-arranged, spared domain of the lesion zone, played a major role in the functional recovery, together with the ipsilesional intact premotor cortex.

Physiological Aging Influence on Brain Hemodynamic Activity during Task-Switching: A fNIRS Study.

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Vasta, Roberta; Cutini, Simone; Cerasa, Antonio; Gramigna, Vera; Olivadese, Giuseppe; Arabia, Gennarina; Quattrone, Aldo

2017-01-01

Task-switching (TS) paradigm is a well-known validated tool useful for exploring the neural substrates of cognitive control, in particular the activity of the lateral and medial prefrontal cortex. This work is aimed at investigating how physiological aging influences hemodynamic response during the execution of a color-shape TS paradigm. A multi-channel near infrared spectroscopy (fNIRS) was used to measure hemodynamic activity in 27 young (30.00 ± 7.90 years) and 11 elderly participants (57.18 ± 9.29 years) healthy volunteers (55% male, age range: (19-69) years) during the execution of a TS paradigm. Two holders were placed symmetrically over the left/right hemispheres to record cortical activity [oxy-(HbO) and deoxy-hemoglobin (HbR) concentration] of the dorso-lateral prefrontal cortex (DLPFC), the dorsal premotor cortex (PMC), and the dorso-medial part of the superior frontal gyrus (sFG). TS paradigm requires participants to repeat the same task over a variable number of trials, and then to switch to a different task during the trial sequence. A two-sample t -test was carried out to detect differences in cortical responses between groups. Multiple linear regression analysis was used to evaluate the impact of age on the prefrontal neural activity. Elderly participants were significantly slower than young participants in both color- ( p aging. Multivariate regression analysis revealed that the HbO mean concentration of switching task in the PMC ( p = 0.01, β = -0.321) and of shape single-task in the sFG ( p = 0.003, β = 0.342) were the best predictors of age effects. Our findings demonstrated that TS might be a reliable instrument to gather a measure of cognitive resources in older people. Moreover, the fNIRS-related brain activity extracted from frontoparietal cortex might become a useful indicator of aging effects.

Men fear other men most: Gender specific brain activations in perceiving threat from dynamic faces and bodies. An fMRI study.

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Mariska Esther Kret

2011-01-01

Full Text Available Gender differences are an important factor regulating daily interactions. Using functional magnetic resonance imaging (fMRI we show that areas involved in processing social signals are activated differently by threatening signals send from male or female facial and bodily expressions and these activity patterns are different for male and female participants. Male participants pay more attention to the female face as shown by increased amygdala activity. But a host of other areas indicate a selective sensitivity for male observers attending to male bodily expressions (extrastriate body area, superior temporal sulcus, fusiform gyrus, pre-supplementary motor area and premotor cortex. This is the first study investigating gender differences in processing dynamic female and male facial and bodily expressions and it illustrates the importance of gender differences in affective communication.

Reduced activation in the mirror neuron system during a virtual social cognition task in euthymic bipolar disorder.

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Kim, Eosu; Jung, Young-Chul; Ku, Jeonghun; Kim, Jae-Jin; Lee, Hyeongrae; Kim, So Young; Kim, Sun I; Cho, Hyun-Sang

2009-11-13

Social cognition entails both cognitive and affective processing, and impairments in both have accounted for residual symptoms of bipolar disorder (BD). However, there has been a lack of studies identifying neural substrates responsible for social cognitive difficulties in BD patients. Fourteen euthymic BD patients and 14 healthy normal controls underwent functional MRI while performing a virtual reality social cognition task, which incorporated both cognitive and emotional dimensions, simulating real-world social situations. During the scanning, subjects tried to guess (attribute) possible reasons for expressed emotion of virtual humans (avatars) while viewing their facial expressions, just after observing their verbal and nonverbal (facial) expressions which were emotionally valenced (happy, angry and neutral). BD patients compared to normal controls showed delayed reaction times in emotional conditions, with comparable response accuracy. Healthy normal controls activated the right anterior cingulate cortex, inferior frontal, and insular cortex in emotional conditions contrasted with neutral control conditions, that is, the regions that have been related to empathic processes during viewing others' emotional expression. Relative to normal controls, BD patients showed reduced activations in the 'mirror neuron system', including the right inferior frontal cortex, premotor cortex, and insula, mainly in angry or happy condition. These results may suggest that, even during euthymic state, BD patients have difficulties in recruiting brain regions for the utilization of emotional cues as a means for understanding others. Clinical attention should be paid to emotion-related residual symptoms to help improve social outcomes in these patients.

The neuroscience of musical improvisation.

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Beaty, Roger E

2015-04-01

Researchers have recently begun to examine the neural basis of musical improvisation, one of the most complex forms of creative behavior. The emerging field of improvisation neuroscience has implications not only for the study of artistic expertise, but also for understanding the neural underpinnings of domain-general processes such as motor control and language production. This review synthesizes functional magnetic resonance imagining (fMRI) studies of musical improvisation, including vocal and instrumental improvisation, with samples of jazz pianists, classical musicians, freestyle rap artists, and non-musicians. A network of prefrontal brain regions commonly linked to improvisatory behavior is highlighted, including the pre-supplementary motor area, medial prefrontal cortex, inferior frontal gyrus, dorsolateral prefrontal cortex, and dorsal premotor cortex. Activation of premotor and lateral prefrontal regions suggests that a seemingly unconstrained behavior may actually benefit from motor planning and cognitive control. Yet activation of cortical midline regions points to a role of spontaneous cognition characteristic of the default network. Together, such results may reflect cooperation between large-scale brain networks associated with cognitive control and spontaneous thought. The improvisation literature is integrated with Pressing's theoretical model, and discussed within the broader context of research on the brain basis of creative cognition. Copyright © 2015 Elsevier Ltd. All rights reserved.

Neural basis of limb ownership in individuals with body integrity identity disorder.

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Milenna T van Dijk

Full Text Available Our body feels like it is ours. However, individuals with body integrity identity disorder (BIID lack this feeling of ownership for distinct limbs and desire amputation of perfectly healthy body parts. This extremely rare condition provides us with an opportunity to study the neural basis underlying the feeling of limb ownership, since these individuals have a feeling of disownership for a limb in the absence of apparent brain damage. Here we directly compared brain activation between limbs that do and do not feel as part of the body using functional MRI during separate tactile stimulation and motor execution experiments. In comparison to matched controls, individuals with BIID showed heightened responsivity of a large somatosensory network including the parietal cortex and right insula during tactile stimulation, regardless of whether the stimulated leg felt owned or alienated. Importantly, activity in the ventral premotor cortex depended on the feeling of ownership and was reduced during stimulation of the alienated compared to the owned leg. In contrast, no significant differences between groups were observed during the performance of motor actions. These results suggest that altered somatosensory processing in the premotor cortex is associated with the feeling of disownership in BIID, which may be related to altered integration of somatosensory and proprioceptive information.

Neural basis of limb ownership in individuals with body integrity identity disorder.

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van Dijk, Milenna T; van Wingen, Guido A; van Lammeren, Anouk; Blom, Rianne M; de Kwaasteniet, Bart P; Scholte, H Steven; Denys, Damiaan

2013-01-01

Our body feels like it is ours. However, individuals with body integrity identity disorder (BIID) lack this feeling of ownership for distinct limbs and desire amputation of perfectly healthy body parts. This extremely rare condition provides us with an opportunity to study the neural basis underlying the feeling of limb ownership, since these individuals have a feeling of disownership for a limb in the absence of apparent brain damage. Here we directly compared brain activation between limbs that do and do not feel as part of the body using functional MRI during separate tactile stimulation and motor execution experiments. In comparison to matched controls, individuals with BIID showed heightened responsivity of a large somatosensory network including the parietal cortex and right insula during tactile stimulation, regardless of whether the stimulated leg felt owned or alienated. Importantly, activity in the ventral premotor cortex depended on the feeling of ownership and was reduced during stimulation of the alienated compared to the owned leg. In contrast, no significant differences between groups were observed during the performance of motor actions. These results suggest that altered somatosensory processing in the premotor cortex is associated with the feeling of disownership in BIID, which may be related to altered integration of somatosensory and proprioceptive information.

Altered cortical activation during action observation in amyotrophic lateral sclerosis patients: a parametric functional MRI study

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Li, Haiqing; Li, Yuxin; Yin, Bo; Tang, Weijun; Yu, Xiangrong; Geng, Daoying [Huashan Hospital, Department of Radiology, Fudan University, Shanghai (China); Chen, Yan [Fudan University, Department of Neurology, Huashan Hospital, Shanghai (China); Huang, Weiyuan [People' s Hospital of Hainan Province, Department of Radiology, Haikou, Hainan Province (China); Zhang, Biyun [Nanjing University of Traditional Chinese Medicine, Department of radiotherapy, Affiliated Jiangsu Province Hospital of Traditional Chinese Medicine, Nanjing (China)

2015-09-15

To investigate functional cerebral abnormalities in patients with amyotrophic lateral sclerosis (ALS) using functional magnetic resonance imaging (fMRI) during action observation. Thirty patients with ALS and 30 matched healthy controls underwent fMRI with an experimental paradigm while observing a video of repetitive flexion-extension of the fingers at three frequency levels or three complexity levels, alternated with periods of a static hand. A parametric analysis was applied to determine the effects of each of the two factors. Action observation activated similar neural networks as the research on execution of action in the ALS patients and healthy subjects in several brain regions related to the mirror-neuron system (MNS). In the ALS patients, in particular, the dorsal lateral premotor cortex (dPMC), inferior parietal gyrus (IPG), and SMA, were more activated compared with the activation in the controls. Increased activation within the primary motor cortex (M1), dPMC, inferior frontal gyrus (IFG), and superior parietal gyrus (SPG) mainly correlated with hand movement frequency/complexity in the videos in the patients compared with controls. The findings indicated an ongoing compensatory process occurring within the higher order motor-processing system of ALS patients, likely to overcome the loss of function. (orig.)

Altered cortical activation during action observation in amyotrophic lateral sclerosis patients: a parametric functional MRI study

International Nuclear Information System (INIS)

Li, Haiqing; Li, Yuxin; Yin, Bo; Tang, Weijun; Yu, Xiangrong; Geng, Daoying; Chen, Yan; Huang, Weiyuan; Zhang, Biyun

2015-01-01

To investigate functional cerebral abnormalities in patients with amyotrophic lateral sclerosis (ALS) using functional magnetic resonance imaging (fMRI) during action observation. Thirty patients with ALS and 30 matched healthy controls underwent fMRI with an experimental paradigm while observing a video of repetitive flexion-extension of the fingers at three frequency levels or three complexity levels, alternated with periods of a static hand. A parametric analysis was applied to determine the effects of each of the two factors. Action observation activated similar neural networks as the research on execution of action in the ALS patients and healthy subjects in several brain regions related to the mirror-neuron system (MNS). In the ALS patients, in particular, the dorsal lateral premotor cortex (dPMC), inferior parietal gyrus (IPG), and SMA, were more activated compared with the activation in the controls. Increased activation within the primary motor cortex (M1), dPMC, inferior frontal gyrus (IFG), and superior parietal gyrus (SPG) mainly correlated with hand movement frequency/complexity in the videos in the patients compared with controls. The findings indicated an ongoing compensatory process occurring within the higher order motor-processing system of ALS patients, likely to overcome the loss of function. (orig.)

The prefrontal cortex shows context-specific changes in effective connectivity to motor or visual cortex during the selection of action or colour

DEFF Research Database (Denmark)

Rowe, James B.; Stephan, Klaas E.; Friston, Karl

2005-01-01

The role of the prefrontal cortex remains controversial. Neuroimaging studies support modality-specific and process-specific functions related to working memory and attention. Its role may also be defined by changes in its influence over other brain regions including sensory and motor cortex. We...... used functional magnetic imaging (fMRI) to study the free selection of actions and colours. Control conditions used externally specified actions and colours. The prefrontal cortex was activated during free selection, regardless of modality, in contrast to modality-specific activations outside...... included high-order interactions between modality, selection and regional activity. There was greater coupling between prefrontal cortex and motor cortex during free selection and action tasks, and between prefrontal cortex and visual cortex during free selection of colours. The results suggest...

Connections of the medial posterior parietal cortex (area 7m) in the monkey.

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Leichnetz, G R

2001-06-01

The afferent and efferent cortical and subcortical connections of the medial posterior parietal cortex (area 7m) were studied in cebus (Cebus apella) and macaque (Macaca fascicularis) monkeys using the retrograde and anterograde capabilities of the horseradish peroxidase (HRP) technique. The principal intraparietal corticocortical connections of area 7m in both cebus and macaque cases were with the ipsilateral medial bank of the intraparietal sulcus (MIP) and adjacent superior parietal lobule (area 5), inferior parietal lobule (area 7a), lateral bank of the IPS (area 7ip), caudal parietal operculum (PGop), dorsal bank of the caudal superior temporal sulcus (visual area MST), and medial prestriate cortex (including visual area PO and caudal medial lobule). Its principal frontal corticocortical connections were with the prefrontal cortex in the shoulder above the principal sulcus and the cortex in the shoulder above the superior ramus of the arcuate sulcus (SAS), the area purported to contain the smooth eye movement-related frontal eye field (FEFsem) in the cebus monkey by other investigators. There were moderate connections with the cortex in the rostral bank of the arcuate sulcus (purported to contain the saccade-related frontal eye field; FEFsac), supplementary eye field (SEF), and rostral dorsal premotor area (PMDr). Area 7m also had major connections with the cingulate cortex (area 23), particularly the ventral bank of the cingulate sulcus. The principal subcortical connections of area 7m were with the dorsal portion of the ventrolateral thalamic (VLc) nucleus, lateral posterior thalamic nucleus, lateral pulvinar, caudal mediodorsal thalamic nucleus and medial pulvinar, central lateral, central superior lateral, and central inferior intralaminar thalamic nuclei, dorsolateral caudate nucleus and putamen, middle region of the claustrum, nucleus of the diagonal band, zona incerta, pregeniculate nucleus, anterior and posterior pretectal nuclei, intermediate layer of

Activation of the insular cortex during dynamic exercise in humans

DEFF Research Database (Denmark)

Williamson, James; Nobrega, A C; McColl, R

1997-01-01

role as a site for regulation of autonomic activity. 2. Eight subjects were studied during voluntary active cycling and passively induced cycling. Additionally, four of the subjects underwent passive movement combined with electrical stimulation of the legs. 3. Increases in regional cerebral blood flow...... during active, but not passive cycling. There were no significant changes in rCBF for the right insula. Also, the magnitude of rCBF increase for leg primary motor areas was significantly greater for both active cycling and passive cycling combined with electrical stimulation compared with passive cycling...... alone. 5. These findings provide the first evidence of insular activation during dynamic exercise in humans, suggesting that the left insular cortex may serve as a site for cortical regulation of cardiac autonomic (parasympathetic) activity. Additionally, findings during passive cycling with electrical...

Weight-specific anticipatory coding of grip force in human dorsal premotor cortex

DEFF Research Database (Denmark)

van Nuenen, Bart F L; Kuhtz-Buschbeck, Johann; Schulz, Christian

2012-01-01

, using either continuous theta burst stimulation (cTBS) at 80% (inhibitory cTBS) or 30% (sham cTBS) of active motor threshold. The conditioning effects of cTBS on preparatory brain activity were assessed with functional MRI, while participants lifted a light or heavy weight in response to a go-cue (S2......). An additional pre-cue (S1) correctly predicted the weight in 75% of the trials. Participants were asked to use this prior information to prepare for the lift. In the sham condition, grip force showed a consistent undershoot, if the S1 incorrectly prompted the preparation of a light lift. Likewise, an S1...... during object lifting....

Origin of human motor readiness field linked to left middle frontal gyrus by MEG and PET

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Pedersen, Jane Rygaard; Johannsen, P; Bak, Christen Kjeldahl

1998-01-01

Combined magnetoencephalography and positron emission tomography identified a prior source of activity in the left middle frontal gyrus duping uncued movements of the right index finger Voluntary movements gave rise to a change in the cortical electrical potential known as the Bereitschaftspotent......Combined magnetoencephalography and positron emission tomography identified a prior source of activity in the left middle frontal gyrus duping uncued movements of the right index finger Voluntary movements gave rise to a change in the cortical electrical potential known...... sources subsequently to be active were mapped to the supplementary motor area, premotor cortex, and motor cortex (M1), all in the left hemisphere. (C) 1998 Academic Press....

Dopamine replacement modulates oscillatory coupling between premotor and motor cortical areas in Parkinson's disease

DEFF Research Database (Denmark)

Herz, Damian Marc; Florin, Esther; Christensen, Mark Schram

2014-01-01

PM to SMA and significantly strengthened coupling in the feedback connection from M1 to lPM expressed as β-β as well as θ-β coupling. Enhancement in cross-frequency θ-β coupling from M1 to lPM was correlated with levodopa-induced improvement in motor function. The results show that PD is associated...... with an altered neural communication between premotor and motor cortical areas, which can be modulated by dopamine replacement....

Age-related vulnerability in the neural systems supporting semantic processing

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Jonathan E Peelle

2013-09-01

Full Text Available Our ability to form abstract representations of objects in semantic memory is crucial to language and thought. The utility of this information relies both on the representations of sensory-motor feature knowledge stored in long-term memory and the executive processes required to retrieve, manipulate, and evaluate this semantic knowledge in a task-relevant manner. These complementary components of semantic memory can be differentially impacted by aging. We investigated semantic processing in normal aging using functional magnetic resonance imaging (fMRI. Young and older adults were asked to judge whether two printed object names match on a particular feature (for example, whether a tomato and strawberry have the same color. The task thus required both retrieval of relevant visual feature knowledge of object concepts and evaluating this information. Objects were drawn from either natural kinds or manufactured objects, and were queried on either color or shape in a factorial design. Behaviorally, all subjects performed well, but older adults could be divided into those whose performance matched that of young adults (better performers and those whose performance was worse (poorer performers. All subjects activated several cortical regions while performing this task, including bilateral inferior and lateral temporal cortex and left frontal and prefrontal cortex. Better performing older adults showed increased overall activity in bilateral premotor cortex and left lateral occipital cortex compared to young adults, and increased activity in these brain regions relative to poorer performing older adults who also showed gray matter atrophy in premotor cortex. These findings highlight the contribution of domain-general executive processing brain regions to semantic memory, and illustrate differences in how these regions are recruited in healthy older adults.

Food related processes in the insular cortex

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Sabine eFrank

2013-08-01

Full Text Available The insular cortex is a multimodal brain region with regional cytoarchitectonic differences indicating various functional specializations. As a multisensory neural node, the insular cortex integrates perception, emotion, interoceptive awareness, cognition, and gustation. Regarding the latter, predominantly the anterior part of the insular cortex is regarded as the primary taste cortex.In this review, we will specifically focus on the involvement of the insula in food processing and on multimodal integration of food-related items. Influencing factors of insular activation elicited by various foods range from calorie-content to the internal physiologic state, body mass index or eating behavior. Sensory perception of food-related stimuli including seeing, smelling, and tasting elicits increased activation in the anterior and mid-dorsal part of the insular cortex. Apart from the pure sensory gustatory processing, there is also a strong association with the rewarding/hedonic aspects of food items, which is reflected in higher insular activity and stronger connections to other reward-related areas. Interestingly, the processing of food items has been found to elicit different insular activation in lean compared to obese subjects and in patients suffering from an eating disorder (anorexia nervosa, bulimia nervosa. The knowledge of functional differences in the insular cortex opens up the opportunity for possible noninvasive treatment approaches for obesity and eating disorders. To target brain functions directly, real-time functional magnetic resonance imaging neurofeedback offers a state-of-the-art tool to learn to control the anterior insular cortex activity voluntarily. First evidence indicates that obese adults have an enhanced ability to regulate the anterior insular cortex.

Effortless awareness: using real time neurofeedback to investigate correlates of posterior cingulate cortex activity in meditators’ self-report.

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Kathleen eGarrison

2013-08-01

Full Text Available Neurophenomenological studies seek to utilize first-person self-report to elucidate cognitive processes related to physiological data. Grounded theory offers an approach to the qualitative analysis of self-report, whereby theoretical constructs are derived from empirical data. Here we used grounded theory methodology to assess how the first-person experience of meditation relates to neural activity in a core region of the default mode network –the posterior cingulate cortex. We analyzed first-person data consisting of meditators’ accounts of their subjective experience during runs of a real-time fMRI neurofeedback study of meditation, and third-person data consisting of corresponding feedback graphs of posterior cingulate cortex activity during the same runs. We found that for meditators, the subjective experiences of ‘undistracted awareness’ such as ‘concentration’ and ‘observing sensory experience’, and ‘effortless doing’ such as ‘observing sensory experience’, ‘not efforting’, and ‘contentment’, correspond with posterior cingulate cortex deactivation. Further, the subjective experiences of ‘distracted awareness’ such as ‘distraction’ and ‘interpreting’, and ‘controlling’ such as ‘efforting’ and ‘discontentment’, correspond with posterior cingulate cortex activation. Moreover, we derived several novel hypotheses about how specific qualities of cognitive processes during meditation relate to posterior cingulate cortex activity, such as the difference between meditation and ‘trying to meditate’. These findings offer novel insights into the relationship between meditation and self-related thinking and neural activity in the default mode network, driven by the first-person experience.

Frontopolar and anterior temporal cortex activation in a moral judgment task. Preliminary functional MRI results in normal subjects

International Nuclear Information System (INIS)

Moll, Jorge; Oliveira-Souza, Ricardo de

2001-01-01

The objective was to study the brain areas which are activated when normal subjects make moral judgments. Ten normal adults underwent BOLD functional magnetic resonance imaging (fMRI) during the auditory presentation of sentences that they were instructed to silently judge as either 'right' or 'wrong'. Half of the sentences had an explicit moral content ('We break the law when necessary'), the other half comprised factual statements devoid of moral connotation ('Stones are made of water'). After scanning, each subject rated the moral content, emotional valence, and judgment difficulty of each sentence on Likert-like scales. To exclude the effect of emotion on the activation results, individual responses were hemo dynamically modeled for event-related f MRI analysis. The general linear model was used to evaluate the brain areas activated by moral judgment. Regions activated during moral judgment included the frontopolar cortex (FPC), medial frontal gyrus, right anterior temporal cortex, lenticular nucleus, and cerebellum. Activation of FPC and medial frontal gyrus (B A 10/46 and 9) were largely independent of emotional experience and represented the largest areas of activation. These results concur with clinical observations assigning a critical role for the frontal poles and right anterior temporal cortex in the mediation of complex judgment processes according to moral constraints. The FPC may work in concert with the orbitofrontal and dorsolateral cortex in the regulation of human social conduct. (author)

Egocentric and allocentric visuospatial working memory in premotor Huntington's disease: A double dissociation with caudate and hippocampal volumes.

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Possin, Katherine L; Kim, Hosung; Geschwind, Michael D; Moskowitz, Tacie; Johnson, Erica T; Sha, Sharon J; Apple, Alexandra; Xu, Duan; Miller, Bruce L; Finkbeiner, Steven; Hess, Christopher P; Kramer, Joel H

2017-07-01

Our brains represent spatial information in egocentric (self-based) or allocentric (landmark-based) coordinates. Rodent studies have demonstrated a critical role for the caudate in egocentric navigation and the hippocampus in allocentric navigation. We administered tests of egocentric and allocentric working memory to individuals with premotor Huntington's disease (pmHD), which is associated with early caudate nucleus atrophy, and controls. Each test had 80 trials during which subjects were asked to remember 2 locations over 1-sec delays. The only difference between these otherwise identical tests was that locations could only be coded in self-based or landmark-based coordinates. We applied a multiatlas-based segmentation algorithm and computed point-wise Jacobian determinants to measure regional variations in caudate and hippocampal volumes from 3T MRI. As predicted, the pmHD patients were significantly more impaired on egocentric working memory. Only egocentric accuracy correlated with caudate volumes, specifically the dorsolateral caudate head, right more than left, a region that receives dense efferents from dorsolateral prefrontal cortex. In contrast, only allocentric accuracy correlated with hippocampal volumes, specifically intermediate and posterior regions that connect strongly with parahippocampal and posterior parietal cortices. These results indicate that the distinction between egocentric and allocentric navigation applies to working memory. The dorsolateral caudate is important for egocentric working memory, which can explain the disproportionate impairment in pmHD. Allocentric working memory, in contrast, relies on the hippocampus and is relatively spared in pmHD. Copyright © 2017 Elsevier Ltd. All rights reserved.

Functional BOLD MRI: comparison of different field strengths in a motor task

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Meindl, T.; Born, C.; Britsch, S.; Reiser, M.; Schoenberg, S.

2008-01-01

The purpose was to evaluate the benefit of an increased field strength for functional magnetic resonance imaging in a motor task. Six right-handed volunteers were scanned at 1.5 T and 3.0 T using a motor task. Each experiment consisted of two runs with four activation blocks, each with right- and left-hand tapping. Analysis was done using BrainVoyagerQX registered . Differences between both field strengths concerning signal to noise (SNR), blood oxygen level-dependent (BOLD) signal change, functional sensitivity and BOLD contrast to noise (CNR) were tested using a paired t test. Delineation of activations and artifacts were graded by two independent readers. Results were further validated by means of a phantom study. The sensorimotor and premotor cortex, the supplementary motor area, subcortical and cerebellar structures were activated at each field strength. Additional activations of the right premotor cortex and right superior temporal gyrus were found at 3.0 T. Signal-to-noise, percentage of BOLD signal change, BOLD CNR and functional sensitivity improved at 3.0 T by a factor of up to 2.4. Functional imaging at 3.0 T results in detection of additional activated areas, increased SNR, BOLD signal change, functional sensitivity and BOLD CNR. (orig.)

NMDA receptors in the avian amygdala and the premotor arcopallium mediate distinct aspects of appetitive extinction learning.

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Gao, Meng; Lengersdorf, Daniel; Stüttgen, Maik C; Güntürkün, Onur

2018-05-02

Extinction learning is an essential mechanism that enables constant adaptation to ever-changing environmental conditions. The underlying neural circuit is mostly studied with rodent models using auditory cued fear conditioning. In order to uncover the variant and the invariant neural properties of extinction learning, we adopted pigeons as an animal model in an appetitive sign-tracking paradigm. The animals firstly learned to respond to two conditioned stimuli in two different contexts (CS-1 in context A and CS-2 in context B), before conditioned responses to the stimuli were extinguished in the opposite contexts (CS-1 in context B and CS-2 in context A). Subsequently, responding to both stimuli was tested in both contexts. Prior to extinction training, we locally injected the N-methyl-d-aspartate receptor (NMDAR) antagonist 2-Amino-5-phosphonovaleric acid (APV) in either the amygdala or the (pre)motor arcopallium to investigate their involvement in extinction learning. Our findings suggest that the encoding of extinction memory required the activation of amygdala, as visible by an impairment of extinction acquisition by concurrent inactivation of local NMDARs. In contrast, consolidation and subsequent retrieval of extinction memory recruited the (pre)motor arcopallium. Also, the inactivation of arcopallial NMDARs induced a general motoric slowing during extinction training. Thus, our results reveal a double dissociation between arcopallium and amygdala with respect to acquisition and consolidation of extinction, respectively. Our study therefore provides new insights on the two key components of the avian extinction network and their resemblance to the data obtained from mammals, possibly indicating a shared neural mechanism underlying extinction learning shaped by evolution. Copyright © 2018 Elsevier B.V. All rights reserved.

Partially overlapping sensorimotor networks underlie speech praxis and verbal short-term memory: evidence from apraxia of speech following acute stroke.

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Hickok, Gregory; Rogalsky, Corianne; Chen, Rong; Herskovits, Edward H; Townsley, Sarah; Hillis, Argye E

2014-01-01

We tested the hypothesis that motor planning and programming of speech articulation and verbal short-term memory (vSTM) depend on partially overlapping networks of neural regions. We evaluated this proposal by testing 76 individuals with acute ischemic stroke for impairment in motor planning of speech articulation (apraxia of speech, AOS) and vSTM in the first day of stroke, before the opportunity for recovery or reorganization of structure-function relationships. We also evaluated areas of both infarct and low blood flow that might have contributed to AOS or impaired vSTM in each person. We found that AOS was associated with tissue dysfunction in motor-related areas (posterior primary motor cortex, pars opercularis; premotor cortex, insula) and sensory-related areas (primary somatosensory cortex, secondary somatosensory cortex, parietal operculum/auditory cortex); while impaired vSTM was associated with primarily motor-related areas (pars opercularis and pars triangularis, premotor cortex, and primary motor cortex). These results are consistent with the hypothesis, also supported by functional imaging data, that both speech praxis and vSTM rely on partially overlapping networks of brain regions.

Generation of novel motor sequences: the neural correlates of musical improvisation.

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Berkowitz, Aaron L; Ansari, Daniel

2008-06-01

While some motor behavior is instinctive and stereotyped or learned and re-executed, much action is a spontaneous response to a novel set of environmental conditions. The neural correlates of both pre-learned and cued motor sequences have been previously studied, but novel motor behavior has thus far not been examined through brain imaging. In this paper, we report a study of musical improvisation in trained pianists with functional magnetic resonance imaging (fMRI), using improvisation as a case study of novel action generation. We demonstrate that both rhythmic (temporal) and melodic (ordinal) motor sequence creation modulate activity in a network of brain regions comprised of the dorsal premotor cortex, the rostral cingulate zone of the anterior cingulate cortex, and the inferior frontal gyrus. These findings are consistent with a role for the dorsal premotor cortex in movement coordination, the rostral cingulate zone in voluntary selection, and the inferior frontal gyrus in sequence generation. Thus, the invention of novel motor sequences in musical improvisation recruits a network of brain regions coordinated to generate possible sequences, select among them, and execute the decided-upon sequence.

Gating of hippocampal activity, plasticity, and memory by entorhinal cortex long-range inhibition.

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Basu, Jayeeta; Zaremba, Jeffrey D; Cheung, Stephanie K; Hitti, Frederick L; Zemelman, Boris V; Losonczy, Attila; Siegelbaum, Steven A

2016-01-08

The cortico-hippocampal circuit is critical for storage of associational memories. Most studies have focused on the role in memory storage of the excitatory projections from entorhinal cortex to hippocampus. However, entorhinal cortex also sends inhibitory projections, whose role in memory storage and cortico-hippocampal activity remains largely unexplored. We found that these long-range inhibitory projections enhance the specificity of contextual and object memory encoding. At the circuit level, these γ-aminobutyric acid (GABA)-releasing projections target hippocampal inhibitory neurons and thus act as a disinhibitory gate that transiently promotes the excitation of hippocampal CA1 pyramidal neurons by suppressing feedforward inhibition. This enhances the ability of CA1 pyramidal neurons to fire synaptically evoked dendritic spikes and to generate a temporally precise form of heterosynaptic plasticity. Long-range inhibition from entorhinal cortex may thus increase the precision of hippocampal-based long-term memory associations by assessing the salience of mnemonormation to the immediate sensory input. Copyright © 2016, American Association for the Advancement of Science.

Guanfacine potentiates the activation of prefrontal cortex evoked by warning signals.

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Clerkin, Suzanne M; Schulz, Kurt P; Halperin, Jeffrey M; Newcorn, Jeffrey H; Ivanov, Iliyan; Tang, Cheuk Y; Fan, Jin

2009-08-15

Warning signals evoke an alert state of readiness that prepares for a rapid response by priming a thalamo-frontal-striatal network that includes the dorsolateral prefrontal cortex (DLPFC). Animal models indicate that noradrenergic input is essential for this stimulus-driven activation of DLPFC, but the precise mechanisms involved have not been determined. We tested the role that postsynaptic alpha(2A) adrenoceptors play in the activation of DLPFC evoked by warning cues using a placebo-controlled challenge with the alpha(2A) agonist guanfacine. Sixteen healthy young adults were scanned twice with event-related functional magnetic resonance imaging (fMRI), while performing a simple cued reaction time (RT) task following administration of a single dose of oral guanfacine (1 mg) and placebo in counterbalanced order. The RT task temporally segregates the neural effects of warning cues and motor responses and minimizes mnemonic demands. Warning cues produced a marked reduction in RT accompanied by significant activation in a distributed thalamo-frontal-striatal network, including bilateral DLPFC. Guanfacine selectively increased the cue-evoked activation of the left DLPFC and right anterior cerebellum, although this increase was not accompanied by further reductions in RT. The effects of guanfacine on DLPFC activation were specifically associated with the warning cue and were not seen for visual- or target-related activation. Guanfacine produced marked increases in the cue-evoked activation of DLPFC that correspond to the well-described actions of postsynaptic alpha(2) adrenoceptor stimulation. The current procedures provide an opportunity to test postsynaptic alpha(2A) adrenoceptor function in the prefrontal cortex in the pathophysiology of several psychiatric disorders.

Involvement of serotonin 2A receptor activation in modulating medial prefrontal cortex and amygdala neuronal activation during novelty-exposure.

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Hervig, Mona El-Sayed; Jensen, Nadja Cecilie Hvid; Rasmussen, Nadja Bredo; Rydbirk, Rasmus; Olesen, Mikkel Vestergaard; Hay-Schmidt, Anders; Pakkenberg, Bente; Aznar, Susana

2017-05-30

The medial prefrontal cortex (PFC) plays a major role in executive function by exerting a top-down control onto subcortical areas. Novelty-induced frontal cortex activation is 5-HT 2A receptor (5-HT 2A R) dependent. Here, we further investigated how blockade of 5-HT 2A Rs in mice exposed to a novel open-field arena affects medial PFC activation and basolateral amygdala (BLA) reactivity. We used c-Fos immunoreactivity (IR) as a marker of neuronal activation and stereological quantification for obtaining the total number of c-Fos-IR neurons as a measure of regional activation. We further examined the impact of 5-HT 2A R blockade on the striatal-projecting BLA neurons. Systemic administration of ketanserin (0.5mg/kg) prior to novel open-field exposure resulted in reduced total numbers of c-Fos-IR cells in dorsomedial PFC areas and the BLA. Moreover, there was a positive correlation between the relative time spent in the centre of the open-field and BLA c-Fos-IR in the ketanserin-treated animals. Unilateral medial PFC lesions blocked this effect, ascertaining an involvement of this frontal cortex area. On the other hand, medial PFC lesioning exacerbated the more anxiogenic-like behaviour of the ketanserin-treated animals, upholding its involvement in modulating averseness. Ketanserin did not affect the number of activated striatal-projecting BLA neurons (measured by number of Cholera Toxin b (CTb) retrograde labelled neurons also being c-Fos-IR) following CTb injection in the ventral striatum. These results support a role of 5-HT 2A R activation in modulating mPFC and BLA activation during exposure to a novel environment, which may be interrelated. Conversely, 5-HT 2A R blockade does not seem to affect the amygdala-striatal projection. Copyright © 2017 Elsevier B.V. All rights reserved.

Extrapunitive and intropunitive individuals activate different parts of the prefrontal cortex under an ego-blocking frustration.

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Minamoto, Takehiro; Osaka, Mariko; Yaoi, Ken; Osaka, Naoyuki

2014-01-01

Different people make different responses when they face a frustrating situation: some punish others (extrapunitive), while others punish themselves (intropunitive). Few studies have investigated the neural structures that differentiate extrapunitive and intropunitive individuals. The present fMRI study explored these neural structures using two different frustrating situations: an ego-blocking situation which blocks a desire or goal, and a superego-blocking situation which blocks self-esteem. In the ego-blocking condition, the extrapunitive group (n = 9) showed greater activation in the bilateral ventrolateral prefrontal cortex, indicating that these individuals prefer emotional processing. On the other hand, the intropunitive group (n = 9) showed greater activation in the left dorsolateral prefrontal cortex, possibly reflecting an effortful control for anger reduction. Such patterns were not observed in the superego-blocking condition. These results indicate that the prefrontal cortex is the source of individual differences in aggression direction in the ego-blocking situation.

Spaced sessions of avoidance extinction reduce spontaneous recovery and promote infralimbic cortex activation.

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Tapias-Espinosa, Carles; Kádár, Elisabet; Segura-Torres, Pilar

2018-01-15

Extinction-based therapies (EBT) are the psychological treatments of choice for certain anxiety disorders, such as post-traumatic stress disorder. However, some patients relapse and suffer spontaneous recovery (SR) of anxiety symptoms and persistence of avoidance behaviour, which underlines the need for improving EBT. In rats, recent evidence has highlighted the relevance of the temporal distribution of extinction sessions in reducing SR of auditory fear conditioning, although it has seldom been studied in procedures involving proactive avoidance responses, such as two-way active avoidance conditioning (TWAA). We examined whether the temporal distribution of two extinction sessions separated by 24h or 7days (contiguous versus spaced extinction paradigms, respectively), influences SR after 28days of a TWAA task. c-Fos expression, as a marker of neuronal activation, was also measured by immunohistochemistry 90min after the SR test in the amygdala and the medial prefrontal cortex. The temporal distribution of extinction sessions did not affect the degree of extinction learning. However, only the rats that underwent the 7-day spaced extinction paradigm maintained the level of extinction in the long term, showing no SR in TWAA. This behavioural finding was consistent with a greater number of c-Fos-labelled neurons in the infralimbic cortex in the 7-day group, and in the Lateral and Central nuclei of the amygdala in the 24-hour group. These findings show that a time-spaced extinction paradigm reduces the spontaneous recovery of active avoidance behaviour, and that this behavioural advantage appears to be related to the activation of the infralimbic cortex. Copyright © 2017 Elsevier B.V. All rights reserved.

The Effects of Context and Attention on Spiking Activity in Human Early Visual Cortex

NARCIS (Netherlands)

Self, Matthew W.; Peters, Judith C.; Possel, Jessy K.; Reithler, Joel; Goebel, Rainer; Ris, Peterjan; Jeurissen, Danique; Reddy, Leila; Claus, Steven; Baayen, Johannes C.; Roelfsema, Pieter R.

2016-01-01

Here we report the first quantitative analysis of spiking activity in human early visual cortex. We recorded multi-unit activity from two electrodes in area V2/V3 of a human patient implanted with depth electrodes as part of her treatment for epilepsy. We observed well-localized multi-unit receptive

The Effects of Context and Attention on Spiking Activity in Human Early Visual Cortex

NARCIS (Netherlands)

Self, Matthew W; Peters, Judith C; Possel, Jessy K; Reithler, Joel; Goebel, Rainer; Ris, Peterjan; Jeurissen, Danique; Reddy, Leila; Claus, Steven; Baayen, Johannes C; Roelfsema, Pieter R

Here we report the first quantitative analysis of spiking activity in human early visual cortex. We recorded multi-unit activity from two electrodes in area V2/V3 of a human patient implanted with depth electrodes as part of her treatment for epilepsy. We observed well-localized multi-unit receptive

Frontopolar and anterior temporal cortex activation in a moral judgment task. Preliminary functional MRI results in normal subjects

Energy Technology Data Exchange (ETDEWEB)

Moll, Jorge [LABS and Rede D' Or Hospitais, Rio de Janeiro RJ (Brazil). Grupo de Neuroimagem e Neurologia do Comportamento; Eslinger, Paul J. [Pensylvania State Univ. (United States). College of Medicine. Div. of Neurology and Behavioral Science; The Milton S. Hershey Medical Center, Hershey, PN (United States); Oliveira-Souza, Ricardo de [Universidade do Rio de Janeiro (UNI-Rio), RJ (Brazil). Hospital Universitario Gaffree e Guinle]. E-mail: neuropsychiatry@hotmail.com

2001-09-01

The objective was to study the brain areas which are activated when normal subjects make moral judgments. Ten normal adults underwent BOLD functional magnetic resonance imaging (fMRI) during the auditory presentation of sentences that they were instructed to silently judge as either 'right' or 'wrong'. Half of the sentences had an explicit moral content ('We break the law when necessary'), the other half comprised factual statements devoid of moral connotation ('Stones are made of water'). After scanning, each subject rated the moral content, emotional valence, and judgment difficulty of each sentence on Likert-like scales. To exclude the effect of emotion on the activation results, individual responses were hemo dynamically modeled for event-related f MRI analysis. The general linear model was used to evaluate the brain areas activated by moral judgment. Regions activated during moral judgment included the frontopolar cortex (FPC), medial frontal gyrus, right anterior temporal cortex, lenticular nucleus, and cerebellum. Activation of FPC and medial frontal gyrus (B A 10/46 and 9) were largely independent of emotional experience and represented the largest areas of activation. These results concur with clinical observations assigning a critical role for the frontal poles and right anterior temporal cortex in the mediation of complex judgment processes according to moral constraints. The FPC may work in concert with the orbitofrontal and dorsolateral cortex in the regulation of human social conduct. (author)

Difference of cerebral activation between healthy volunteers and MCI-patients during navigation in a virtual reality environment. A parametric study using O15 H2O-PET

International Nuclear Information System (INIS)

Drzezga, A.; Wermke, M.D.; Schwaiger, M.; Grimmer, T.; Foerstl, H.; Kurz, A.

2002-01-01

Aim: To assess the regional cerebral activation during navigation in a virtual reality (VR) environment in healthy volunteers and patients with mild cognitive impairment (MCI) to identify possible differences in cerebral processing of a complex cognitive task. Materials and Methods: A computer-based VR-system has been developed that allows movements in a virtual labyrinth using a special space-mouse and 3-dimensional perception by shutter-glasses. In 11 healthy, right-handed volunteers (3 female, age 66+/-9 years) and 9 patients with MCI (3 female, 69+/-10 years, diagnosis according to criteria of the Mayo-Clinic) twelve H215O PET-scans were performed (each 370 MBq i.v.-bolus). During the scan subjects had to navigate actively from startpoint to a predefined destination point. Three difficulty levels were presented, 4 times each, in randomized order. Test performance (speed, mistakes) was co-registered. PET data were analyzed using statistical parametric mapping (SPM99, Wellcome Inst., London, UK) including correlation analysis with the acquired test performance results. A significance threshold of p<0,001 uncorrected was applied. Results: In both groups a similar network of extended cerebral activation was identified during active navigation, including maxima in the cerebellum, premotor cortex (Brodmann area [BA] 6), parietal cortex (BA 7, 40) and posterior cingulate cortex (BA 31). However, in MCI-patients a significantly stronger activation of anterior cingulate cortex (BA 24), prefrontal cortex (BA 8) and parietal cortex (BA 40) was observed, as compared to healthy volunteers. Conclusion: The applied combination of PET and VR-technology allows to examine the processing of complex cognitive tasks in the brain. During active navigation significant differences have been observed between the activated cerebral networks in MCI-patients and healthy volunteers. In MCI-patients stronger activation has been identified in cerebral regions associated with attention and

Sleep spindle activity in double cortex syndrome: a case report.

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Sforza, Emilia; Marcoz, Jean-Pierre; Foletti, Giovanni

2010-09-01

Cortical dysgenesis is increasingly recognised as a cause of epilepsy. We report a case with double cortex heterotopia and secondarily generalized seizures with a generalised spike wave pattern. During the course of the disease, the child developed electrical status epilepticus in slow wave sleep. From the first examination, sleep pattern revealed increased frequency and amplitude of spindle activity, more evident in anterior areas. The role of the thalamocortical pathway in increased sleep spindle activity is discussed with emphasis on the possible role of altered thalamocortical pathways in abnormal cortical migration. A strong suspicion of cortical dysgenesis may therefore be based on specific EEG sleep patterns.

Amygdala lesions disrupt modulation of functional MRI activity evoked by facial expression in the monkey inferior temporal cortex

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Hadj-Bouziane, Fadila; Liu, Ning; Bell, Andrew H.; Gothard, Katalin M.; Luh, Wen-Ming; Tootell, Roger B. H.; Murray, Elisabeth A.; Ungerleider, Leslie G.

2012-01-01

We previously showed that facial expressions modulate functional MRI activity in the face-processing regions of the macaque monkey’s amygdala and inferior temporal (IT) cortex. Specifically, we showed that faces expressing emotion yield greater activation than neutral faces; we term this difference the “valence effect.” We hypothesized that amygdala lesions would disrupt the valence effect by eliminating the modulatory feedback from the amygdala to the IT cortex. We compared the valence effects within the IT cortex in monkeys with excitotoxic amygdala lesions (n = 3) with those in intact control animals (n = 3) using contrast agent-based functional MRI at 3 T. Images of four distinct monkey facial expressions—neutral, aggressive (open mouth threat), fearful (fear grin), and appeasing (lip smack)—were presented to the subjects in a blocked design. Our results showed that in monkeys with amygdala lesions the valence effects were strongly disrupted within the IT cortex, whereas face responsivity (neutral faces > scrambled faces) and face selectivity (neutral faces > non-face objects) were unaffected. Furthermore, sparing of the anterior amygdala led to intact valence effects in the anterior IT cortex (which included the anterior face-selective regions), whereas sparing of the posterior amygdala led to intact valence effects in the posterior IT cortex (which included the posterior face-selective regions). Overall, our data demonstrate that the feedback projections from the amygdala to the IT cortex mediate the valence effect found there. Moreover, these modulatory effects are consistent with an anterior-to-posterior gradient of projections, as suggested by classical tracer studies. PMID:23184972

Extrapunitive and intropunitive individuals activate different parts of the prefrontal cortex under an ego-blocking frustration.

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Takehiro Minamoto

Full Text Available Different people make different responses when they face a frustrating situation: some punish others (extrapunitive, while others punish themselves (intropunitive. Few studies have investigated the neural structures that differentiate extrapunitive and intropunitive individuals. The present fMRI study explored these neural structures using two different frustrating situations: an ego-blocking situation which blocks a desire or goal, and a superego-blocking situation which blocks self-esteem. In the ego-blocking condition, the extrapunitive group (n = 9 showed greater activation in the bilateral ventrolateral prefrontal cortex, indicating that these individuals prefer emotional processing. On the other hand, the intropunitive group (n = 9 showed greater activation in the left dorsolateral prefrontal cortex, possibly reflecting an effortful control for anger reduction. Such patterns were not observed in the superego-blocking condition. These results indicate that the prefrontal cortex is the source of individual differences in aggression direction in the ego-blocking situation.

Associative-memory representations emerge as shared spatial patterns of theta activity spanning the primate temporal cortex.

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Nakahara, Kiyoshi; Adachi, Ken; Kawasaki, Keisuke; Matsuo, Takeshi; Sawahata, Hirohito; Majima, Kei; Takeda, Masaki; Sugiyama, Sayaka; Nakata, Ryota; Iijima, Atsuhiko; Tanigawa, Hisashi; Suzuki, Takafumi; Kamitani, Yukiyasu; Hasegawa, Isao

2016-06-10

Highly localized neuronal spikes in primate temporal cortex can encode associative memory; however, whether memory formation involves area-wide reorganization of ensemble activity, which often accompanies rhythmicity, or just local microcircuit-level plasticity, remains elusive. Using high-density electrocorticography, we capture local-field potentials spanning the monkey temporal lobes, and show that the visual pair-association (PA) memory is encoded in spatial patterns of theta activity in areas TE, 36, and, partially, in the parahippocampal cortex, but not in the entorhinal cortex. The theta patterns elicited by learned paired associates are distinct between pairs, but similar within pairs. This pattern similarity, emerging through novel PA learning, allows a machine-learning decoder trained on theta patterns elicited by a particular visual item to correctly predict the identity of those elicited by its paired associate. Our results suggest that the formation and sharing of widespread cortical theta patterns via learning-induced reorganization are involved in the mechanisms of associative memory representation.

Spiking in auditory cortex following thalamic stimulation is dominated by cortical network activity

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Krause, Bryan M.; Raz, Aeyal; Uhlrich, Daniel J.; Smith, Philip H.; Banks, Matthew I.

2014-01-01

The state of the sensory cortical network can have a profound impact on neural responses and perception. In rodent auditory cortex, sensory responses are reported to occur in the context of network events, similar to brief UP states, that produce “packets” of spikes and are associated with synchronized synaptic input (Bathellier et al., 2012; Hromadka et al., 2013; Luczak et al., 2013). However, traditional models based on data from visual and somatosensory cortex predict that ascending sensory thalamocortical (TC) pathways sequentially activate cells in layers 4 (L4), L2/3, and L5. The relationship between these two spatio-temporal activity patterns is unclear. Here, we used calcium imaging and electrophysiological recordings in murine auditory TC brain slices to investigate the laminar response pattern to stimulation of TC afferents. We show that although monosynaptically driven spiking in response to TC afferents occurs, the vast majority of spikes fired following TC stimulation occurs during brief UP states and outside the context of the L4>L2/3>L5 activation sequence. Specifically, monosynaptic subthreshold TC responses with similar latencies were observed throughout layers 2–6, presumably via synapses onto dendritic processes located in L3 and L4. However, monosynaptic spiking was rare, and occurred primarily in L4 and L5 non-pyramidal cells. By contrast, during brief, TC-induced UP states, spiking was dense and occurred primarily in pyramidal cells. These network events always involved infragranular layers, whereas involvement of supragranular layers was variable. During UP states, spike latencies were comparable between infragranular and supragranular cells. These data are consistent with a model in which activation of auditory cortex, especially supragranular layers, depends on internally generated network events that represent a non-linear amplification process, are initiated by infragranular cells and tightly regulated by feed-forward inhibitory

Atypical neural substrates of Embedded Figures Task performance in children with Autism Spectrum Disorder.

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Lee, Philip S; Foss-Feig, Jennifer; Henderson, Joshua G; Kenworthy, Lauren E; Gilotty, Lisa; Gaillard, William D; Vaidya, Chandan J

2007-10-15

Superior performance on the Embedded Figures Task (EFT) has been attributed to weak central coherence in perceptual processing in Autism Spectrum Disorder (ASD). The present study used functional magnetic resonance imaging to examine the neural basis of EFT performance in 7- to 12-year-old ASD children and age- and IQ-matched controls. ASD children activated only a subset of the distributed network of regions activated in controls. In frontal cortex, control children activated left dorsolateral, medial and dorsal premotor regions whereas ASD children only activated the dorsal premotor region. In parietal and occipital cortices, activation was bilateral in control children but unilateral (left superior parietal and right occipital) in ASD children. Further, extensive bilateral ventral temporal activation was observed in control, but not ASD children. ASD children performed the EFT at the same level as controls but with reduced cortical involvement, suggesting that disembedded visual processing is accomplished parsimoniously by ASD relative to typically developing brains.

Cortical regions involved in the generation of musical structures during improvisation in pianists.

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Bengtsson, Sara L; Csíkszentmihályi, Mihály; Ullén, Fredrik

2007-05-01

Studies on simple pseudorandom motor and cognitive tasks have shown that the dorsolateral prefrontal cortex and rostral premotor areas are involved in free response selection. We used functional magnetic resonance imaging to investigate whether these brain regions are also involved in free generation of responses in a more complex creative behavior: musical improvisation. Eleven professional pianists participated in the study. In one condition, Improvise, the pianist improvised on the basis of a visually displayed melody. In the control condition, Reproduce, the participant reproduced his previous improvisation from memory. Participants were able to reproduce their improvisations with a high level of accuracy, and the contrast Improvise versus Reproduce was thus essentially matched in terms of motor output and sensory feedback. However, the Improvise condition required storage in memory of the improvisation. We therefore also included a condition FreeImp, where the pianist improvised but was instructed not to memorize his performance. To locate brain regions involved in musical creation, we investigated the activations in the Improvise-Reproduce contrast that were also present in FreeImp contrasted with a baseline rest condition. Activated brain regions included the right dorsolateral prefrontal cortex, the presupplementary motor area, the rostral portion of the dorsal premotor cortex, and the left posterior part of the superior temporal gyrus. We suggest that these regions are part of a network involved in musical creation, and discuss their possible functional roles.

Primary visual cortex activity along the apparent-motion trace reflects illusory perception.

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Lars Muckli

2005-08-01

Full Text Available The illusion of apparent motion can be induced when visual stimuli are successively presented at different locations. It has been shown in previous studies that motion-sensitive regions in extrastriate cortex are relevant for the processing of apparent motion, but it is unclear whether primary visual cortex (V1 is also involved in the representation of the illusory motion path. We investigated, in human subjects, apparent-motion-related activity in patches of V1 representing locations along the path of illusory stimulus motion using functional magnetic resonance imaging. Here we show that apparent motion caused a blood-oxygenation-level-dependent response along the V1 representations of the apparent-motion path, including regions that were not directly activated by the apparent-motion-inducing stimuli. This response was unaltered when participants had to perform an attention-demanding task that diverted their attention away from the stimulus. With a bistable motion quartet, we confirmed that the activity was related to the conscious perception of movement. Our data suggest that V1 is part of the network that represents the illusory path of apparent motion. The activation in V1 can be explained either by lateral interactions within V1 or by feedback mechanisms from higher visual areas, especially the motion-sensitive human MT/V5 complex.

Abnormal Amygdala and Prefrontal Cortex Activation to Facial Expressions in Pediatric Bipolar Disorder

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Garrett, Amy S.; Reiss, Allan L.; Howe, Meghan E.; Kelley, Ryan G.; Singh, Manpreet K.; Adleman, Nancy E.; Karchemskiy, Asya; Chang, Kiki D.

2012-01-01

Objective: Previous functional magnetic resonance imaging (fMRI) studies in pediatric bipolar disorder (BD) have reported greater amygdala and less dorsolateral prefrontal cortex (DLPFC) activation to facial expressions compared to healthy controls. The current study investigates whether these differences are associated with the early or late…

Evidence for a functional subdivision of Premotor Ear-Eye Field (Area 8B.

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Marco eLanzilotto

2015-01-01

Full Text Available The Supplementary Eye Field (SEF and the Frontal Eye Field (FEF have been described as participating in gaze shift control. Recent evidence suggests, however, that other areas of the dorsomedial prefrontal cortex also influence gaze shift. Herein, we have investigated electrically evoked ear- and eye movements from the Premotor Ear-Eye Field, or PEEF (area 8B of macaque monkeys. We stimulated PEEF during spontaneous condition (outside the task performance and during the execution of a visual fixation task (VFT. In the first case, we functionally identified two regions within the PEEF: a core and a belt. In the core region, stimulation elicited forward ear movements; regarding the evoked eye movements, in some penetrations, stimulation elicited contraversive fixed-vectors with a mean amplitude of 5.14°; while in other penetrations, we observed prevalently contralateral goal-directed eye movements having end-points that fell within 15° in respect to the primary eye position. On the contrary, in the belt region, stimulation elicited backward ear movements; regarding the eye movements, in some penetrations stimulation elicited prevalently contralateral goal-directed eye movements having end-points that fell within 15° in respect to the primary eye position, while in the lateral edge of the investigated region, stimulation elicited contralateral goal-directed eye movements having end-points that fell beyond 15° in respect to the primary eye position. Stimulation during VFT either did not elicit eye movements or evoked saccades of only a few degrees. Finally, even though no head rotation movements were observed during the stimulation period, we viewed a relationship between the duration of stimulation and the neck forces exerted by the monkey’s head. We propose an updated vision of the PEEF composed of two functional regions, core and belt, which may be involved in integrating auditory and visual information important to the programming of gaze

Brain activation profiles during kinesthetic and visual imagery: An fMRI study.

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Kilintari, Marina; Narayana, Shalini; Babajani-Feremi, Abbas; Rezaie, Roozbeh; Papanicolaou, Andrew C

2016-09-01

The aim of this study was to identify brain regions involved in motor imagery and differentiate two alternative strategies in its implementation: imagining a motor act using kinesthetic or visual imagery. Fourteen adults were precisely instructed and trained on how to imagine themselves or others perform a movement sequence, with the aim of promoting kinesthetic and visual imagery, respectively, in the context of an fMRI experiment using block design. We found that neither modality of motor imagery elicits activation of the primary motor cortex and that each of the two modalities involves activation of the premotor area which is also activated during action execution and action observation conditions, as well as of the supplementary motor area. Interestingly, the visual and the posterior cingulate cortices show reduced BOLD signal during both imagery conditions. Our results indicate that the networks of regions activated in kinesthetic and visual imagery of motor sequences show a substantial, while not complete overlap, and that the two forms of motor imagery lead to a differential suppression of visual areas. Copyright © 2016 Elsevier B.V. All rights reserved.

Characterizing context-dependent differential firing activity in the hippocampus and entorhinal cortex.

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Prerau, Michael J; Lipton, Paul A; Eichenbaum, Howard B; Eden, Uri T

2014-04-01

The rat hippocampus and entorhinal cortex have been shown to possess neurons with place fields that modulate their firing properties under different behavioral contexts. Such context-dependent changes in neural activity are commonly studied through electrophysiological experiments in which a rat performs a continuous spatial alternation task on a T-maze. Previous research has analyzed context-based differential firing during this task by describing differences in the mean firing activity between left-turn and right-turn experimental trials. In this article, we develop qualitative and quantitative methods to characterize and compare changes in trial-to-trial firing rate variability for sets of experimental contexts. We apply these methods to cells in the CA1 region of hippocampus and in the dorsocaudal medial entorhinal cortex (dcMEC), characterizing the context-dependent differences in spiking activity during spatial alternation. We identify a subset of cells with context-dependent changes in firing rate variability. Additionally, we show that dcMEC populations encode turn direction uniformly throughout the T-maze stem, whereas CA1 populations encode context at major waypoints in the spatial trajectory. Our results suggest scenarios in which individual cells that sparsely provide information on turn direction might combine in the aggregate to produce a robust population encoding. Copyright © 2014 Wiley Periodicals, Inc.

Acute caffeine administration impact on working memory-related brain activation and functional connectivity in the elderly: a BOLD and perfusion MRI study.

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Haller, S; Rodriguez, C; Moser, D; Toma, S; Hofmeister, J; Sinanaj, I; Van De Ville, D; Giannakopoulos, P; Lovblad, K-O

2013-10-10

In young individuals, caffeine-mediated blockade of adenosine receptors and vasoconstriction has direct repercussions on task-related activations, changes in functional connectivity, as well as global vascular effects. To date, no study has explored the effect of caffeine on brain activation patterns during highly demanding cognitive tasks in the elderly. This prospective, placebo-controlled crossover design comprises 24 healthy elderly individuals (mean age 68.8 ± 4.0 years, 17 females) performing a 2-back working memory (WM) task in functional magnetic resonance imaging (fMRI). Analyses include complimentary assessment of task-related activations (general linear model, GLM), functional connectivity (tensorial independent component analysis, TICA), and baseline perfusion (arterial spin labeling). Despite a reduction in whole-brain global perfusion (-22.7%), caffeine-enhanced task-related GLM activation in a local and distributed network is most pronounced in the bilateral striatum and to a lesser degree in the right middle and inferior frontal gyrus, bilateral insula, left superior and inferior parietal lobule as well as in the cerebellum bilaterally. TICA was significantly enhanced (+8.2%) in caffeine versus placebo in a distributed and task-relevant network including the pre-frontal cortex, the supplementary motor area, the ventral premotor cortex and the parietal cortex as well as the occipital cortex (visual stimuli) and basal ganglia. The inverse comparison of placebo versus caffeine had no significant difference. Activation strength of the task-relevant-network component correlated with response accuracy for caffeine yet not for placebo, indicating a selective cognitive effect of caffeine. The present findings suggest that acute caffeine intake enhances WM-related brain activation as well as functional connectivity of blood oxygen level-dependent fMRI in elderly individuals. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

Distinct timescales of population coding across cortex.

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Runyan, Caroline A; Piasini, Eugenio; Panzeri, Stefano; Harvey, Christopher D

2017-08-03

The cortex represents information across widely varying timescales. For instance, sensory cortex encodes stimuli that fluctuate over few tens of milliseconds, whereas in association cortex behavioural choices can require the maintenance of information over seconds. However, it remains poorly understood whether diverse timescales result mostly from features intrinsic to individual neurons or from neuronal population activity. This question remains unanswered, because the timescales of coding in populations of neurons have not been studied extensively, and population codes have not been compared systematically across cortical regions. Here we show that population codes can be essential to achieve long coding timescales. Furthermore, we find that the properties of population codes differ between sensory and association cortices. We compared coding for sensory stimuli and behavioural choices in auditory cortex and posterior parietal cortex as mice performed a sound localization task. Auditory stimulus information was stronger in auditory cortex than in posterior parietal cortex, and both regions contained choice information. Although auditory cortex and posterior parietal cortex coded information by tiling in time neurons that were transiently informative for approximately 200 milliseconds, the areas had major differences in functional coupling between neurons, measured as activity correlations that could not be explained by task events. Coupling among posterior parietal cortex neurons was strong and extended over long time lags, whereas coupling among auditory cortex neurons was weak and short-lived. Stronger coupling in posterior parietal cortex led to a population code with long timescales and a representation of choice that remained consistent for approximately 1 second. In contrast, auditory cortex had a code with rapid fluctuations in stimulus and choice information over hundreds of milliseconds. Our results reveal that population codes differ across cortex

Involvement of serotonin 2A receptor activation in modulating medial prefrontal cortex and amygdala neuronal activation during novelty-exposure

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Hervig, Mona El-Sayed; Jensen, Nadja Cecilie Hvid; Rasmussen, Nadja Bredo

2017-01-01

The medial prefrontal cortex (PFC) plays a major role in executive function by exerting a top-down control onto subcortical areas. Novelty-induced frontal cortex activation is 5-HT2A receptor (5-HT2AR) dependent. Here, we further investigated how blockade of 5-HT2ARs in mice exposed to a novel open-field...... of 5-HT2AR blockade on the striatal-projecting BLA neurons. Systemic administration of ketanserin (0.5 mg/kg) prior to novel open-field exposure resulted in reduced total numbers of c-Fos-IR cells in dorsomedial PFC areas and the BLA. Moreover, there was a positive correlation between the relative time...... spent in the centre of the open-field and BLA c-Fos-IR in the ketanserin-treated animals. Unilateral medial PFC lesions blocked this effect, ascertaining an involvement of this frontal cortex area. On the other hand, medial PFC lesioning exacerbated the more anxiogenic-like behaviour of the ketanserin...

Compensatory recombination phenomena of neurological functions in central dysphagia patients

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Xiao-dong Yuan

2015-01-01

Full Text Available We speculate that cortical reactions evoked by swallowing activity may be abnormal in patients with central infarction with dysphagia. The present study aimed to detect functional imaging features of cerebral cortex in central dysphagia patients by using blood oxygen level-dependent functional magnetic resonance imaging techniques. The results showed that when normal controls swallowed, primary motor cortex (BA4, insula (BA13, premotor cortex (BA6/8, supramarginal gyrus (BA40, and anterior cingulate cortex (BA24/32 were activated, and that the size of the activated areas were larger in the left hemisphere compared with the right. In recurrent cerebral infarction patients with central dysphagia, BA4, BA13, BA40 and BA6/8 areas were activated, while the degree of activation in BA24/32 was decreased. Additionally, more areas were activated, including posterior cingulate cortex (BA23/31, visual association cortex (BA18/19, primary auditory cortex (BA41 and parahippocampal cortex (BA36. Somatosensory association cortex (BA7 and left cerebellum in patients with recurrent cerebral infarction with central dysphagia were also activated. Experimental findings suggest that the cerebral cortex has obvious hemisphere lateralization in response to swallowing, and patients with recurrent cerebral infarction with central dysphagia show compensatory recombination phenomena of neurological functions. In rehabilitative treatment, using the favorite food of patients can stimulate swallowing through visual, auditory, and other nerve conduction pathways, thus promoting compensatory recombination of the central cortex functions.

Electrocorticographic activity over sensorimotor cortex and motor function in awake behaving rats.

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Boulay, Chadwick B; Chen, Xiang Yang; Wolpaw, Jonathan R

2015-04-01

Sensorimotor cortex exerts both short-term and long-term control over the spinal reflex pathways that serve motor behaviors. Better understanding of this control could offer new possibilities for restoring function after central nervous system trauma or disease. We examined the impact of ongoing sensorimotor cortex (SMC) activity on the largely monosynaptic pathway of the H-reflex, the electrical analog of the spinal stretch reflex. In 41 awake adult rats, we measured soleus electromyographic (EMG) activity, the soleus H-reflex, and electrocorticographic activity over the contralateral SMC while rats were producing steady-state soleus EMG activity. Principal component analysis of electrocorticographic frequency spectra before H-reflex elicitation consistently revealed three frequency bands: μβ (5-30 Hz), low γ (γ1; 40-85 Hz), and high γ (γ2; 100-200 Hz). Ongoing (i.e., background) soleus EMG amplitude correlated negatively with μβ power and positively with γ1 power. In contrast, H-reflex size correlated positively with μβ power and negatively with γ1 power, but only when background soleus EMG amplitude was included in the linear model. These results support the hypothesis that increased SMC activation (indicated by decrease in μβ power and/or increase in γ1 power) simultaneously potentiates the H-reflex by exciting spinal motoneurons and suppresses it by decreasing the efficacy of the afferent input. They may help guide the development of new rehabilitation methods and of brain-computer interfaces that use SMC activity as a substitute for lost or impaired motor outputs. Copyright © 2015 the American Physiological Society.

Intra- and Interhemispheric Propagation of Electrophysiological Synchronous Activity and Its Modulation by Serotonin in the Cingulate Cortex of Juvenile Mice.

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Víctor Rovira

Full Text Available Disinhibition of the cortex (e.g., by GABA -receptor blockade generates synchronous and oscillatory electrophysiological activity that propagates along the cortex. We have studied, in brain slices of the cingulate cortex of mice (postnatal age 14-20 days, the propagation along layer 2/3 as well as the interhemispheric propagation through the corpus callosum of synchronous discharges recorded extracellularly and evoked in the presence of 10 μM bicuculline by electrical stimulation of layer 1. The latency of the responses obtained at the same distance from the stimulus electrode was longer in anterior cingulate cortex (ACC: 39.53 ± 2.83 ms, n = 7 than in retrosplenial cortex slices (RSC: 21.99 ± 2.75 ms, n = 5; p<0.05, which is equivalent to a lower propagation velocity in the dorso-ventral direction in ACC than in RSC slices (43.0 mm/s vs 72.9 mm/s. We studied the modulation of this propagation by serotonin. Serotonin significantly increased the latency of the intracortical synchronous discharges (18.9% in the ipsilateral hemisphere and 40.2% in the contralateral hemisphere, and also increased the interhemispheric propagation time by 86.4%. These actions of serotonin were mimicked by the activation of either 5-HT1B or 5-HT2A receptors, but not by the activation of the 5-HT1A subtype. These findings provide further knowledge about the propagation of synchronic electrical activity in the cerebral cortex, including its modulation by serotonin, and suggest the presence of deep differences between the ACC and RSC in the structure of the local cortical microcircuits underlying the propagation of synchronous discharges.

The rhythms of steady posture: Motor commands as spatially organized oscillation patterns

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Heitmann, S.; Boonstra, T.W.; Gong, P.; Breakspear, M.; Ermentrout, B.

2015-01-01

Beta-band (15-30. Hz) oscillations in motor cortex have been implicated in voluntary movement and postural control. Yet the mechanisms linking those oscillations to function remains elusive. Recently, spatial waves of synchronized beta oscillations have been observed in primary and pre-motor cortex

The brain's dorsal route for speech represents word meaning: evidence from gesture.

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Josse, Goulven; Joseph, Sabine; Bertasi, Eric; Giraud, Anne-Lise

2012-01-01

The dual-route model of speech processing includes a dorsal stream that maps auditory to motor features at the sublexical level rather than at the lexico-semantic level. However, the literature on gesture is an invitation to revise this model because it suggests that the premotor cortex of the dorsal route is a major site of lexico-semantic interaction. Here we investigated lexico-semantic mapping using word-gesture pairs that were either congruent or incongruent. Using fMRI-adaptation in 28 subjects, we found that temporo-parietal and premotor activity during auditory processing of single action words was modulated by the prior audiovisual context in which the words had been repeated. The BOLD signal was suppressed following repetition of the auditory word alone, and further suppressed following repetition of the word accompanied by a congruent gesture (e.g. ["grasp" + grasping gesture]). Conversely, repetition suppression was not observed when the same action word was accompanied by an incongruent gesture (e.g. ["grasp" + sprinkle]). We propose a simple model to explain these results: auditory and visual information converge onto premotor cortex where it is represented in a comparable format to determine (in)congruence between speech and gesture. This ability of the dorsal route to detect audiovisual semantic (in)congruence suggests that its function is not restricted to the sublexical level.

Kainate-induced network activity in the anterior cingulate cortex.

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Shinozaki, R; Hojo, Y; Mukai, H; Hashizume, M; Murakoshi, T

2016-06-14

Anterior cingulate cortex (ACC) plays a pivotal role in higher order processing of cognition, attention and emotion. The network oscillation is considered an essential means for integration of these CNS functions. The oscillation power and coherence among related areas are often dis-regulated in several psychiatric and pathological conditions with a hemispheric asymmetric manner. Here we describe the network-based activity of field potentials recorded from the superficial layer of the mouse ACC in vitro using submerged type recordings. A short activation by kainic acid administration to the preparation induced populational activities ranging over several frequency bands including theta (3-8Hz), alpha (8-12Hz), beta (13-30Hz), low gamma (30-50Hz) and high gamma (50-80Hz). These responses were repeatable and totally abolished by tetrodotoxin, and greatly diminished by inhibitors of ionotropic and metabotropic glutamate receptors, GABAA receptor or gap-junctions. These observations suggest that the kainate-induced network activity can be a useful model of the network oscillation in the ACC circuit. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Human medial frontal cortex activity predicts learning from errors.

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Hester, Robert; Barre, Natalie; Murphy, Kevin; Silk, Tim J; Mattingley, Jason B

2008-08-01

Learning from errors is a critical feature of human cognition. It underlies our ability to adapt to changing environmental demands and to tune behavior for optimal performance. The posterior medial frontal cortex (pMFC) has been implicated in the evaluation of errors to control behavior, although it has not previously been shown that activity in this region predicts learning from errors. Using functional magnetic resonance imaging, we examined activity in the pMFC during an associative learning task in which participants had to recall the spatial locations of 2-digit targets and were provided with immediate feedback regarding accuracy. Activity within the pMFC was significantly greater for errors that were subsequently corrected than for errors that were repeated. Moreover, pMFC activity during recall errors predicted future responses (correct vs. incorrect), despite a sizeable interval (on average 70 s) between an error and the next presentation of the same recall probe. Activity within the hippocampus also predicted future performance and correlated with error-feedback-related pMFC activity. A relationship between performance expectations and pMFC activity, in the absence of differing reinforcement value for errors, is consistent with the idea that error-related pMFC activity reflects the extent to which an outcome is "worse than expected."

Modulation of fusiform cortex activity by cholinesterase inhibition predicts effects on subsequent memory.

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Bentley, P; Driver, J; Dolan, R J

2009-09-01

Cholinergic influences on memory are likely to be expressed at several processing stages, including via well-recognized effects of acetylcholine on stimulus processing during encoding. Since previous studies have shown that cholinesterase inhibition enhances visual extrastriate cortex activity during stimulus encoding, especially under attention-demanding tasks, we tested whether this effect correlates with improved subsequent memory. In a within-subject physostigmine versus placebo design, we measured brain activity with functional magnetic resonance imaging while healthy and mild Alzheimer's disease subjects performed superficial and deep encoding tasks on face (and building) visual stimuli. We explored regions in which physostigmine modulation of face-selective neural responses correlated with physostigmine effects on subsequent recognition performance. In healthy subjects physostigmine led to enhanced later recognition for deep- versus superficially-encoded faces, which correlated across subjects with a physostigmine-induced enhancement of face-selective responses in right fusiform cortex during deep- versus superficial-encoding tasks. In contrast, the Alzheimer's disease group showed neither a depth of processing effect nor restoration of this with physostigmine. Instead, patients showed a task-independent improvement in confident memory with physostigmine, an effect that correlated with enhancements in face-selective (but task-independent) responses in bilateral fusiform cortices. Our results indicate that one mechanism by which cholinesterase inhibitors can improve memory is by enhancing extrastriate cortex stimulus selectivity at encoding, in a manner that for healthy people but not in Alzheimer's disease is dependent upon depth of processing.

MEG reveals a fast pathway from somatosensory cortex to occipital areas via posterior parietal cortex in a blind subject.

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Ioannides, Andreas A; Liu, Lichan; Poghosyan, Vahe; Saridis, George A; Gjedde, Albert; Ptito, Maurice; Kupers, Ron

2013-01-01

Cross-modal activity in visual cortex of blind subjects has been reported during performance of variety of non-visual tasks. A key unanswered question is through which pathways non-visual inputs are funneled to the visual cortex. Here we used tomographic analysis of single trial magnetoencephalography (MEG) data recorded from one congenitally blind and two sighted subjects after stimulation of the left and right median nerves at three intensities: below sensory threshold, above sensory threshold and above motor threshold; the last sufficient to produce thumb twitching. We identified reproducible brain responses in the primary somatosensory (S1) and motor (M1) cortices at around 20 ms post-stimulus, which were very similar in sighted and blind subjects. Time-frequency analysis revealed strong 45-70 Hz activity at latencies of 20-50 ms in S1 and M1, and posterior parietal cortex Brodmann areas (BA) 7 and 40, which compared to lower frequencies, were substantially more pronounced in the blind than the sighted subjects. Critically, at frequencies from α-band up to 100 Hz we found clear, strong, and widespread responses in the visual cortex of the blind subject, which increased with the intensity of the somatosensory stimuli. Time-delayed mutual information (MI) revealed that in blind subject the stimulus information is funneled from the early somatosensory to visual cortex through posterior parietal BA 7 and 40, projecting first to visual areas V5 and V3, and eventually V1. The flow of information through this pathway occurred in stages characterized by convergence of activations into specific cortical regions. In sighted subjects, no linked activity was found that led from the somatosensory to the visual cortex through any of the studied brain regions. These results provide the first evidence from MEG that in blind subjects, tactile information is routed from primary somatosensory to occipital cortex via the posterior parietal cortex.

Partially Overlapping Sensorimotor Networks Underlie Speech Praxis and Verbal Short-Term Memory: Evidence from Apraxia of Speech Following Acute Stroke

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Gregory eHickok

2014-08-01

Full Text Available We tested the hypothesis that motor planning and programming of speech articulation and verbal short-term memory (vSTM depend on partially overlapping networks of neural regions. We evaluated this proposal by testing 76 individuals with acute ischemic stroke for impairment in motor planning of speech articulation (apraxia of speech; AOS and vSTM in the first day of stroke, before the opportunity for recovery or reorganization of structure-function relationships. We also evaluate areas of both infarct and low blood flow that might have contributed to AOS or impaired vSTM in each person. We found that AOS was associated with tissue dysfunction in motor-related areas (posterior primary motor cortex, pars opercularis; premotor cortex, insula and sensory-related areas (primary somatosensory cortex, secondary somatosensory cortex, parietal operculum/auditory cortex; while impaired vSTM was associated with primarily motor-related areas (pars opercularis and pars triangularis, premotor cortex, and primary motor cortex. These results are consistent with the hypothesis, also supported by functional imaging data, that both speech praxis and vSTM rely on partially overlapping networks of brain regions.

rTMS of the prefrontal cortex has analgesic effects on neuropathic pain in subjects with spinal cord injury.

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Nardone, R; Höller, Y; Langthaler, P B; Lochner, P; Golaszewski, S; Schwenker, K; Brigo, F; Trinka, E

2017-01-01

Repetitive transcranial magnetic stimulation study. The analgesic effects of repetitive transcranial magnetic stimulation (rTMS) in chronic pain have been the focus of several studies. In particular, rTMS of the premotor cortex/dorsolateral prefrontal cortex (PMC/DLPFC) changes pain perception in healthy subjects and has analgesic effects in acute postoperative pain, as well as in fibromyalgia patients. However, its effect on neuropathic pain in patients with traumatic spinal cord injury (SCI) has not been assessed. Merano (Italy) and Salzburg (Austria). In this study, we performed PMC/DLPFC rTMS in subjects with SCI and neuropathic pain. Twelve subjects with chronic cervical or thoracic SCI were randomized to receive 1250 pulses at 10 Hz rTMS (n=6) or sham rTMS (n=6) treatment for 10 sessions over 2 weeks. The visual analog scale, the sensory and affective pain rating indices of the McGill Pain Questionnaire (MPQ), the Hamilton Depression Rating Scale and the Hamilton Anxiety Rating Scale were used to assed pain and mood at baseline (T0), 1 day after the first week of treatment (T1), 1 day (T2), 1 week (T3) and 1 month (T4) after the last intervention. Subjects who received active rTMS had a statistically significant reduction in pain symptoms in comparison with their baseline pain, whereas sham rTMS participants had a non-significant change in daily pain from their baseline pain. The findings of this preliminary study in a small patient sample suggest that rTMS of the PMC/DLPFC may be effective in relieving neuropathic pain in SCI patients.

Imaging the spatio-temporal dynamics of supragranular activity in the rat somatosensory cortex in response to stimulation of the paws.

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M L Morales-Botello

Full Text Available We employed voltage-sensitive dye (VSD imaging to investigate the spatio-temporal dynamics of the responses of the supragranular somatosensory cortex to stimulation of the four paws in urethane-anesthetized rats. We obtained the following main results. (1 Stimulation of the contralateral forepaw evoked VSD responses with greater amplitude and smaller latency than stimulation of the contralateral hindpaw, and ipsilateral VSD responses had a lower amplitude and greater latency than contralateral responses. (2 While the contralateral stimulation initially activated only one focus, the ipsilateral stimulation initially activated two foci: one focus was typically medial to the focus activated by contralateral stimulation and was stereotaxically localized in the motor cortex; the other focus was typically posterior to the focus activated by contralateral stimulation and was stereotaxically localized in the somatosensory cortex. (3 Forepaw and hindpaw somatosensory stimuli activated large areas of the sensorimotor cortex, well beyond the forepaw and hindpaw somatosensory areas of classical somatotopic maps, and forepaw stimuli activated larger cortical areas with greater activation velocity than hindpaw stimuli. (4 Stimulation of the forepaw and hindpaw evoked different cortical activation dynamics: forepaw responses displayed a clear medial directionality, whereas hindpaw responses were much more uniform in all directions. In conclusion, this work offers a complete spatio-temporal map of the supragranular VSD cortical activation in response to stimulation of the paws, showing important somatotopic differences between contralateral and ipsilateral maps as well as differences in the spatio-temporal activation dynamics in response to forepaw and hindpaw stimuli.

Effects of Increasing Neuromuscular Electrical Stimulation Current Intensity on Cortical Sensorimotor Network Activation: A Time Domain fNIRS Study.

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Makii Muthalib

Full Text Available Neuroimaging studies have shown neuromuscular electrical stimulation (NMES-evoked movements activate regions of the cortical sensorimotor network, including the primary sensorimotor cortex (SMC, premotor cortex (PMC, supplementary motor area (SMA, and secondary somatosensory area (S2, as well as regions of the prefrontal cortex (PFC known to be involved in pain processing. The aim of this study, on nine healthy subjects, was to compare the cortical network activation profile and pain ratings during NMES of the right forearm wrist extensor muscles at increasing current intensities up to and slightly over the individual maximal tolerated intensity (MTI, and with reference to voluntary (VOL wrist extension movements. By exploiting the capability of the multi-channel time domain functional near-infrared spectroscopy technique to relate depth information to the photon time-of-flight, the cortical and superficial oxygenated (O2Hb and deoxygenated (HHb hemoglobin concentrations were estimated. The O2Hb and HHb maps obtained using the General Linear Model (NIRS-SPM analysis method, showed that the VOL and NMES-evoked movements significantly increased activation (i.e., increase in O2Hb and corresponding decrease in HHb in the cortical layer of the contralateral sensorimotor network (SMC, PMC/SMA, and S2. However, the level and area of contralateral sensorimotor network (including PFC activation was significantly greater for NMES than VOL. Furthermore, there was greater bilateral sensorimotor network activation with the high NMES current intensities which corresponded with increased pain ratings. In conclusion, our findings suggest that greater bilateral sensorimotor network activation profile with high NMES current intensities could be in part attributable to increased attentional/pain processing and to increased bilateral sensorimotor integration in these cortical regions.

Effects of Increasing Neuromuscular Electrical Stimulation Current Intensity on Cortical Sensorimotor Network Activation: A Time Domain fNIRS Study.

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Muthalib, Makii; Re, Rebecca; Zucchelli, Lucia; Perrey, Stephane; Contini, Davide; Caffini, Matteo; Spinelli, Lorenzo; Kerr, Graham; Quaresima, Valentina; Ferrari, Marco; Torricelli, Alessandro

2015-01-01

Neuroimaging studies have shown neuromuscular electrical stimulation (NMES)-evoked movements activate regions of the cortical sensorimotor network, including the primary sensorimotor cortex (SMC), premotor cortex (PMC), supplementary motor area (SMA), and secondary somatosensory area (S2), as well as regions of the prefrontal cortex (PFC) known to be involved in pain processing. The aim of this study, on nine healthy subjects, was to compare the cortical network activation profile and pain ratings during NMES of the right forearm wrist extensor muscles at increasing current intensities up to and slightly over the individual maximal tolerated intensity (MTI), and with reference to voluntary (VOL) wrist extension movements. By exploiting the capability of the multi-channel time domain functional near-infrared spectroscopy technique to relate depth information to the photon time-of-flight, the cortical and superficial oxygenated (O2Hb) and deoxygenated (HHb) hemoglobin concentrations were estimated. The O2Hb and HHb maps obtained using the General Linear Model (NIRS-SPM) analysis method, showed that the VOL and NMES-evoked movements significantly increased activation (i.e., increase in O2Hb and corresponding decrease in HHb) in the cortical layer of the contralateral sensorimotor network (SMC, PMC/SMA, and S2). However, the level and area of contralateral sensorimotor network (including PFC) activation was significantly greater for NMES than VOL. Furthermore, there was greater bilateral sensorimotor network activation with the high NMES current intensities which corresponded with increased pain ratings. In conclusion, our findings suggest that greater bilateral sensorimotor network activation profile with high NMES current intensities could be in part attributable to increased attentional/pain processing and to increased bilateral sensorimotor integration in these cortical regions.

Motor demand-dependent activation of ipsilateral motor cortex.

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Buetefisch, Cathrin M; Revill, Kate Pirog; Shuster, Linda; Hines, Benjamin; Parsons, Michael

2014-08-15

The role of ipsilateral primary motor cortex (M1) in hand motor control during complex task performance remains controversial. Bilateral M1 activation is inconsistently observed in functional (f)MRI studies of unilateral hand performance. Two factors limit the interpretation of these data. As the motor tasks differ qualitatively in these studies, it is conceivable that M1 contributions differ with the demand on skillfulness. Second, most studies lack the verification of a strictly unilateral execution of the motor task during the acquisition of imaging data. Here, we use fMRI to determine whether ipsilateral M1 activity depends on the demand for precision in a pointing task where precision varied quantitatively while movement trajectories remained equal. Thirteen healthy participants used an MRI-compatible joystick to point to targets of four different sizes in a block design. A clustered acquisition technique allowed simultaneous fMRI/EMG data collection and confirmed that movements were strictly unilateral. Accuracy of performance increased with target size. Overall, the pointing task revealed activation in contralateral and ipsilateral M1, extending into contralateral somatosensory and parietal areas. Target size-dependent activation differences were found in ipsilateral M1 extending into the temporal/parietal junction, where activation increased with increasing demand on accuracy. The results suggest that ipsilateral M1 is active during the execution of a unilateral motor task and that its activity is modulated by the demand on precision. Copyright © 2014 the American Physiological Society.

A Biologically Inspired Learning to Grasp System

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2001-10-25

possible extensive discussions of data on the premotor cortex and monkey grasping circuit with Giacomo Rizzolatti , Vittorio Gallese, to whom we express...premotor specialisation for the different types of grasps that Rizzolatti group [3] has found be formed at this age yet. Infants will need to...our gratitude. REFERENCES [1] M. Jeannerod, M.A. Arbib, G. Rizzolatti , H. Sakata, “Grasping objects: the cortical mechanisms of visuomotor

The modulation of venlafaxine on cortical activation of language area in healthy subjects with fMRI study.

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Xie, Qi; Liu, Yan; Li, Chun-Yong; Song, Xue-Zhu; Wang, Jun; Han, Li-Xin; Bai, Hong-Min

2012-10-01

Previous studies have shown that selective serotonin reuptake inhibitors, activators of the cortex, apparently improved language functional recovery after brain damage rather than simply affective disorders. Our aim was to determine whether venlafaxine (an agonist of both norepinephrine and 5-hydroxytryptamine) could modulate language cortex function. A double-blind, crossover, randomized design was used to compare two 7-day treatment sessions with either venlafaxine (75 mg per day) or placebo. A functional magnetic resonance imaging experiment and two language function tests were performed on eight healthy males (mean age, 28.25 ± 3.15 years) at the end of each session, i.e., study entry, after venlafaxine, and after placebo (days 0, 7, and 18). Hyperactivation (venlafaxine minus placebo >0) or hypoactivation (placebo minus venlafaxine >0) by venlaxafine was assessed on the basis of the activation-baseline contrast. The naming score (P gyrus frontalis medius and the bilateral fusiform gyrus and the bilateral outer occipital lobes, (2) hyperactivation was observed in the adjoining area of posterior upper Broca area and premotor area in the dominant hemisphere in venlafaxine session (after venlafaxine), (3) the hyperactivation of the left gyrus frontalis medius on fMRI and the increase in naming test score were positively correlated, and (4) by contrast, we observed hypoactivation in the temporo-parieto-occipital region in venlafaxine session (after venlafaxine). This improvement may be related to increased phonics-related output in the frontal language cortex of the dominant hemisphere.

Abnormal amygdala connectivity in patients with primary insomnia: evidence from resting state fMRI.

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Huang, Zhaoyang; Liang, Peipeng; Jia, Xiuqin; Zhan, Shuqin; Li, Ning; Ding, Yan; Lu, Jie; Wang, Yuping; Li, Kuncheng

2012-06-01

Neurobiological mechanisms underlying insomnia are poorly understood. Previous findings indicated that dysfunction of the emotional circuit might contribute to the neurobiological mechanisms underlying insomnia. The present study will test this hypothesis by examining alterations in functional connectivity of the amygdala in patients with primary insomnia (PI). Resting-state functional connectivity analysis was used to examine the temporal correlation between the amygdala and whole-brain regions in 10 medication-naive PI patients and 10 age- and sex-matched healthy controls. Additionally, the relationship between the abnormal functional connectivity and insomnia severity was investigated. We found decreased functional connectivity mainly between the amygdala and insula, striatum and thalamus, and increased functional connectivity mainly between the amygdala and premotor cortex, sensorimotor cortex in PI patients as compared to healthy controls. The connectivity of the amygdala with the premotor cortex in PI patients showed significant positive correlation with the total score of the Pittsburgh Sleep Quality Index (PSQI). The decreased functional connectivity between the amygdala and insula, striatum, and thalamus suggests that dysfunction in the emotional circuit might contribute to the neurobiological mechanisms underlying PI. The increased functional connectivity of the amygdala with the premotor and sensorimotor cortex demonstrates a compensatory mechanism to overcome the negative effects of sleep deficits and maintain the psychomotor performances in PI patients. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Abnormal amygdala connectivity in patients with primary insomnia: Evidence from resting state fMRI

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Huang Zhaoyang; Liang Peipeng; Jia Xiuqin; Zhan Shuqin; Li Ning; Ding Yan; Lu Jie; Wang Yuping; Li Kuncheng

2012-01-01

Background: Neurobiological mechanisms underlying insomnia are poorly understood. Previous findings indicated that dysfunction of the emotional circuit might contribute to the neurobiological mechanisms underlying insomnia. The present study will test this hypothesis by examining alterations in functional connectivity of the amygdala in patients with primary insomnia (PI). Methods: Resting-state functional connectivity analysis was used to examine the temporal correlation between the amygdala and whole-brain regions in 10 medication-naive PI patients and 10 age- and sex-matched healthy controls. Additionally, the relationship between the abnormal functional connectivity and insomnia severity was investigated. Results: We found decreased functional connectivity mainly between the amygdala and insula, striatum and thalamus, and increased functional connectivity mainly between the amygdala and premotor cortex, sensorimotor cortex in PI patients as compared to healthy controls. The connectivity of the amygdala with the premotor cortex in PI patients showed significant positive correlation with the total score of the Pittsburgh Sleep Quality Index (PSQI). Conclusions: The decreased functional connectivity between the amygdala and insula, striatum, and thalamus suggests that dysfunction in the emotional circuit might contribute to the neurobiological mechanisms underlying PI. The increased functional connectivity of the amygdala with the premotor and sensorimotor cortex demonstrates a compensatory mechanism to overcome the negative effects of sleep deficits and maintain the psychomotor performances in PI patients.

Right inferior frontal cortex activity correlates with tolcapone responsivity in problem and pathological gamblers

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Andrew S. Kayser

2017-01-01

Full Text Available Failures of self-regulation in problem and pathological gambling (PPG are thought to emerge from failures of top-down control, reflected neurophysiologically in a reduced capacity of prefrontal cortex to influence activity within subcortical structures. In patients with addictions, these impairments have been argued to alter evaluation of reward within dopaminergic neuromodulatory systems. Previously we demonstrated that augmenting dopamine tone in frontal cortex via use of tolcapone, an inhibitor of the dopamine-degrading enzyme catechol-O-methyltransferase (COMT, reduced delay discounting, a measure of impulsivity, in healthy subjects. To evaluate this potentially translational approach to augmenting prefrontal inhibitory control, here we hypothesized that increasing cortical dopamine tone would reduce delay discounting in PPG subjects in proportion to its ability to augment top-down control. To causally test this hypothesis, we administered the COMT inhibitor tolcapone in a randomized, double-blind, placebo-controlled, within-subject study of 17 PPG subjects who performed a delay discounting task while functional MRI images were obtained. In this subject population, we found that greater BOLD activity during the placebo condition within the right inferior frontal cortex (RIFC, a region thought to be important for inhibitory control, correlated with greater declines in impulsivity on tolcapone versus placebo. Intriguingly, connectivity between RIFC and the right striatum, and not the level of activity within RIFC itself, increased on tolcapone versus placebo. Together, these findings support the hypothesis that tolcapone-mediated increases in top-down control may reduce impulsivity in PPG subjects, a finding with potential translational relevance for gambling disorders, and for behavioral addictions in general.

Weaker Seniors Exhibit Motor Cortex Hypoexcitability and Impairments in Voluntary Activation.

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Clark, Brian C; Taylor, Janet L; Hong, S Lee; Law, Timothy D; Russ, David W

2015-09-01

Weakness predisposes seniors to a fourfold increase in functional limitations. The potential for age-related degradation in nervous system function to contribute to weakness and physical disability has garnered much interest of late. In this study, we tested the hypothesis that weaker seniors have impairments in voluntary (neural) activation and increased indices of GABAergic inhibition of the motor cortex, assessed using transcranial magnetic stimulation. Young adults (N = 46; 21.2±0.5 years) and seniors (N = 42; 70.7±0.9 years) had their wrist flexion strength quantified along with voluntary activation capacity (by comparing voluntary and electrically evoked forces). Single-pulse transcranial magnetic stimulation was used to measure motor-evoked potential amplitude and silent period duration during isometric contractions at 15% and 30% of maximum strength. Paired-pulse transcranial magnetic stimulation was used to measure intracortical facilitation and short-interval and long-interval intracortical inhibition. The primary analysis compared seniors to young adults. The secondary analysis compared stronger seniors (top two tertiles) to weaker seniors (bottom tertile) based on strength relative to body weight. The most novel findings were that weaker seniors exhibited: (i) a 20% deficit in voluntary activation; (ii) ~20% smaller motor-evoked potentials during the 30% contraction task; and (iii) nearly twofold higher levels of long-interval intracortical inhibition under resting conditions. These findings indicate that weaker seniors exhibit significant impairments in voluntary activation, and that this impairment may be mechanistically associated with increased GABAergic inhibition of the motor cortex. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Dynamics of human subthalamic neuron phase-locking to motor and sensory cortical oscillations during movement.

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Lipski, Witold J; Wozny, Thomas A; Alhourani, Ahmad; Kondylis, Efstathios D; Turner, Robert S; Crammond, Donald J; Richardson, Robert Mark

2017-09-01

Coupled oscillatory activity recorded between sensorimotor regions of the basal ganglia-thalamocortical loop is thought to reflect information transfer relevant to movement. A neuronal firing-rate model of basal ganglia-thalamocortical circuitry, however, has dominated thinking about basal ganglia function for the past three decades, without knowledge of the relationship between basal ganglia single neuron firing and cortical population activity during movement itself. We recorded activity from 34 subthalamic nucleus (STN) neurons, simultaneously with cortical local field potentials and motor output, in 11 subjects with Parkinson's disease (PD) undergoing awake deep brain stimulator lead placement. STN firing demonstrated phase synchronization to both low- and high-beta-frequency cortical oscillations, and to the amplitude envelope of gamma oscillations, in motor cortex. We found that during movement, the magnitude of this synchronization was dynamically modulated in a phase-frequency-specific manner. Importantly, we found that phase synchronization was not correlated with changes in neuronal firing rate. Furthermore, we found that these relationships were not exclusive to motor cortex, because STN firing also demonstrated phase synchronization to both premotor and sensory cortex. The data indicate that models of basal ganglia function ultimately will need to account for the activity of populations of STN neurons that are bound in distinct functional networks with both motor and sensory cortices and code for movement parameters independent of changes in firing rate. NEW & NOTEWORTHY Current models of basal ganglia-thalamocortical networks do not adequately explain simple motor functions, let alone dysfunction in movement disorders. Our findings provide data that inform models of human basal ganglia function by demonstrating how movement is encoded by networks of subthalamic nucleus (STN) neurons via dynamic phase synchronization with cortex. The data also

Body-Selective Areas in the Visual Cortex are less active in Children than in Adults

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Paddy D Ross

2014-11-01

Full Text Available Our ability to read other people’s non-verbal signals gets refined throughout childhood and adolescence. How this is paralleled by brain development has been investigated mainly with regards to face perception, showing a protracted functional development of the face-selective visual cortical areas. In view of the importance of whole-body expressions in interpersonal communication it is important to understand the development of brain areas sensitive to these social signals.Here we used functional magnetic resonance imaging (fMRI to compare brain activity in a group of 24 children (age 6-11 and 26 adults while they passively watched short videos of body or object movements. We observed activity in similar regions in both groups; namely the extra-striate body area (EBA, fusiform body area (FBA, posterior superior temporal sulcus (pSTS, amygdala and premotor regions. Adults showed additional activity in the inferior frontal gyrus. Within the main body-selective regions (EBA, FBA and pSTS, the strength and spatial extent of fMRI signal change was larger in adults than in children. Multivariate Bayesian analysis showed that the spatial pattern of neural representation within those regions did not change over age.Our results indicate, for the first time, that body perception, like face perception, is still maturing through the second decade of life.

Persistent neural activity in auditory cortex is related to auditory working memory in humans and nonhuman primates.

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Huang, Ying; Matysiak, Artur; Heil, Peter; König, Reinhard; Brosch, Michael

2016-07-20

Working memory is the cognitive capacity of short-term storage of information for goal-directed behaviors. Where and how this capacity is implemented in the brain are unresolved questions. We show that auditory cortex stores information by persistent changes of neural activity. We separated activity related to working memory from activity related to other mental processes by having humans and monkeys perform different tasks with varying working memory demands on the same sound sequences. Working memory was reflected in the spiking activity of individual neurons in auditory cortex and in the activity of neuronal populations, that is, in local field potentials and magnetic fields. Our results provide direct support for the idea that temporary storage of information recruits the same brain areas that also process the information. Because similar activity was observed in the two species, the cellular bases of some auditory working memory processes in humans can be studied in monkeys.

Antioxidant Activity of Grapevine Leaf Extracts against Oxidative Stress Induced by Carbon Tetrachloride in Cerebral Cortex, Hippocampus and Cerebellum of Rats

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Mariane Wohlenberg

2014-04-01

Full Text Available In recent years, it has become increasingly important to study the beneficial properties of derivatives of grapes and grapevine. The objective of this study was to determine the antioxidant activity of Vitis labrusca leaf extracts, comparing conventional and organic grapevines, in different brain areas of rats. We used male Wistar rats treated with grapevine leaf extracts for a period of 14 days, and on the 15th day, we administered in half of the rats, mineral oil and the other half, carbon tetrachloride (CCl4. The animals were euthanized by decapitation and the cerebral cortex, hippocampus and cerebellum were removed to assess oxidative stress parameters and the activity of antioxidant enzymes. Lipid peroxidation levels (TBARS were unchanged. However, CCl4 induced oxidative damage to proteins in all tissues studied, and this injury was prevented by both extracts. Superoxide dismutase (SOD activity was increased by CCl4 in the cerebral cortex and decreased in other tissues. However, CCl4 increased catalase (CAT activity in the cerebellum and decreased it in the cerebral cortex. The SOD/CAT ratio was restored in the cerebellum by both extracts and only in the cerebral cortex by the organic extract.

Identification of prefrontal cortex (BA10) activation while performing Stroop test using diffuse optical tomography

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Khadka, Sabin; Chityala, Srujan R.; Tian, Fenghua; Liu, Hanli

2011-03-01

Stroop test is commonly used as a behavior-testing tool for psychological examinations that are related to attention and cognitive control of the human brain. Studies have shown activations in Broadmann area 10 (BA10) of prefrontal cortex (PFC) during attention and cognitive process. The use of diffuse optical tomography (DOT) for human brain mapping is becoming more prevalent. In this study we expect to find neural correlates between the performed cognitive tasks and hemodynamic signals detected by a DOT system. Our initial observation showed activation of oxy-hemoglobin concentration in BA 10, which is consistent with some results seen by positron emission tomography (PET) and functional magnetic resonance imaging (fMRI). Our study demonstrates the possibility of combining DOT with Stroop test to quantitatively investigate cognitive functions of the human brain at the prefrontal cortex.

MEG reveals a fast pathway from somatosensory cortex to occipital areas via posterior parietal cortex in a blind subject

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Andreas A Ioannides

2013-08-01

Full Text Available Cross-modal activity in visual cortex of blind subjects has been reported during performance of variety of non-visual tasks. A key unanswered question is through which pathways non-visual inputs are funneled to the visual cortex. Here we used tomographic analysis of single trial magnetoencephalography (MEG data recorded from one congenitally blind and two sighted subjects after stimulation of the left and right median nerves at three intensities: below sensory threshold, above sensory threshold and above motor threshold; the last sufficient to produce thumb twitching. We identified reproducible brain responses in the primary somatosensory (S1 and motor (M1 cortices at around 20 ms post-stimulus, which were very similar in sighted and blind subjects. Time-frequency analysis revealed strong 45 to 70 Hz activity at latencies of 20 to 50 ms in S1 and M1, and posterior parietal cortex Brodmann areas (BA 7 and 40, which compared to lower frequencies, were substantially more pronounced in the blind than the sighted subjects. Critically, at frequencies from α-band up to 100 Hz we found clear, strong and widespread responses in the visual cortex of the blind subject, which increased with the intensity of the somatosensory stimuli. Time-delayed mutual information (MI revealed that in blind subject the stimulus information is funneled from the early somatosensory to visual cortex through posterior parietal BA 7 and 40, projecting first to visual areas V5 and V3, and eventually V1. The flow of information through this pathway occured in stages characterized by convergence of activations into specific cortical regions. In sighted subjects, no linked activity was found that led from the somatosensory to the visual cortex through any of the studied brain regions. These results provide the first evidence from MEG that in blind subjects, tactile information is routed from primary somatosensory to occipital cortex via the posterior parietal cortex.

Performance monitoring in the medial frontal cortex and related neural networks: From monitoring self actions to understanding others' actions.

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Ninomiya, Taihei; Noritake, Atsushi; Ullsperger, Markus; Isoda, Masaki

2018-04-27

Action is a key channel for interacting with the outer world. As such, the ability to monitor actions and their consequences - regardless as to whether they are self-generated or other-generated - is of crucial importance for adaptive behavior. The medial frontal cortex (MFC) has long been studied as a critical node for performance monitoring in nonsocial contexts. Accumulating evidence suggests that the MFC is involved in a wide range of functions necessary for one's own performance monitoring, including error detection, and monitoring and resolving response conflicts. Recent studies, however, have also pointed to the importance of the MFC in performance monitoring under social conditions, ranging from monitoring and understanding others' actions to reading others' mental states, such as their beliefs and intentions (i.e., mentalizing). Here we review the functional roles of the MFC and related neural networks in performance monitoring in both nonsocial and social contexts, with an emphasis on the emerging field of a social systems neuroscience approach using macaque monkeys as a model system. Future work should determine the way in which the MFC exerts its monitoring function via interactions with other brain regions, such as the superior temporal sulcus in the mentalizing system and the ventral premotor cortex in the mirror system. Copyright © 2018. Published by Elsevier B.V.

Medial Prefrontal Cortex Activation Is Commonly Invoked by Reputation of Self and Romantic Partners

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Kawamichi, Hiroaki; Sasaki, Akihiro T.; Matsunaga, Masahiro; Yoshihara, Kazufumi; Takahashi, Haruka K.; Tanabe, Hiroki C.; Sadato, Norihiro

2013-01-01

The reputation of others influences partner selection in human cooperative behaviors through verbal reputation representation. Although the way in which humans represent the verbal reputations of others is a pivotal issue for social neuroscience, the neural correlates underlying the representation of verbal reputations of others are unclear. Humans primarily depend on self-evaluation when assessing reputation of self. Likewise, humans might primarily depend on self-evaluation of others when representing their reputation. As interaction promotes the formation of more nuanced, individualized impressions of an interaction partner, humans tend to form self-evaluations of persons with whom they are intimate in their daily life. Thus, we hypothesized that the representation of reputation of others is modulated by intimacy due to one’s own evaluation formation of that person. To test this hypothesis, we conducted a functional magnetic resonance imaging experiment with 11 pairs of romantic partners while they viewed an evaluation of a target person (self, partner [intimate other], or stranger [non-intimate other]), made by other evaluators. When compared with strangers, viewing evaluations of self and partner activated overlapping regions in the medial prefrontal cortex. Verbal reputation of self-specific activation was found in the precuneus, which represents self-related processing. The data suggest that midline structures represent reputation of self. In addition, intimacy-modulated activation in the medial prefrontal cortex suggests that the verbal reputation of intimate others is represented similarly to reputation of self. These results suggest that the reputation representation in the medial prefrontal cortex is engaged by verbal reputation of self and intimate others stemming from both own and other evaluators’ judgments. PMID:24086409

Functional rearrangement of the primary and secondary motor cortex in patients with primary tumors of the central nervous system located in the region of the central sulcus depending on the histopathological type and the size of tumor: Examination by means of functional magnetic resonance imaging

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Bryszewski, Bartosz; Pfajfer, Lucjan; Antosik-Biernacka, Aneta; Tybor, Krzysztof; Śmigielski, Janusz; Zawirski, Marek; Majos, Agata

2012-01-01

The aim of this study was to analyze the reorganization of the centers of the motor cortex in patients with primary neuroepithelial tumors of the central nervous system (CNS) located in the region of the central sulcus in relation to the histopathological type and the size of tumor, as determined by means of functional magnetic resonance imaging (fMRI). The fMRI was performed prior to the surgical treatment of patients with tumors located in the region of the central sulcus (WHO stage I and II, n=15; WHO stage III and IV, n=25). The analysis included a record of the activity in the areas of the primary motor cortex (M1) and the secondary motor cortex: the premotor cortex (PMA) and the accessory motor area (SMA). The results were correlated with the histopathological type of the tumor and its size expressed in cm 3 . The frequency of activation of the motor center was higher in the group of patients who had less aggressive tumors, such as low-grade glioma (LGG), as well as in tumors of lower volume, and this was true both for the hemisphere where the tumor was located and in the contralateral one. Mean values of t-statistics of activation intensity, mean numbers of activated clusters, and their ranges were lower in all analyzed motor areas of LGG tumors. The values of t-statistics and activation areas were higher in the case of small tumors located in ipsilateral centers, and in large tumors located in contralateral centers, aside from the SMA area where the values of t-statistics were equal for both groups. The contralateral SMA area was characterized by the highest stability of all examined centers of secondary motor cortex. No significant association (p>0.05) was observed between the absolute value of the mean registered activity (t-statistics) and the size of examined areas (number of clusters) when the groups were stratified with regards to the analyzed parameters. The presence of a neoplastic lesion, its histopathological type and finally its size modulate the

Tinnitus intensity dependent gamma oscillations of the contralateral auditory cortex.

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Elsa van der Loo

Full Text Available BACKGROUND: Non-pulsatile tinnitus is considered a subjective auditory phantom phenomenon present in 10 to 15% of the population. Tinnitus as a phantom phenomenon is related to hyperactivity and reorganization of the auditory cortex. Magnetoencephalography studies demonstrate a correlation between gamma band activity in the contralateral auditory cortex and the presence of tinnitus. The present study aims to investigate the relation between objective gamma-band activity in the contralateral auditory cortex and subjective tinnitus loudness scores. METHODS AND FINDINGS: In unilateral tinnitus patients (N = 15; 10 right, 5 left source analysis of resting state electroencephalographic gamma band oscillations shows a strong positive correlation with Visual Analogue Scale loudness scores in the contralateral auditory cortex (max r = 0.73, p<0.05. CONCLUSION: Auditory phantom percepts thus show similar sound level dependent activation of the contralateral auditory cortex as observed in normal audition. In view of recent consciousness models and tinnitus network models these results suggest tinnitus loudness is coded by gamma band activity in the contralateral auditory cortex but might not, by itself, be responsible for tinnitus perception.

Connecting to create: expertise in musical improvisation is associated with increased functional connectivity between premotor and prefrontal areas.

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Pinho, Ana Luísa; de Manzano, Örjan; Fransson, Peter; Eriksson, Helene; Ullén, Fredrik

2014-04-30

Musicians have been used extensively to study neural correlates of long-term practice, but no studies have investigated the specific effects of training musical creativity. Here, we used human functional MRI to measure brain activity during improvisation in a sample of 39 professional pianists with varying backgrounds in classical and jazz piano playing. We found total hours of improvisation experience to be negatively associated with activity in frontoparietal executive cortical areas. In contrast, improvisation training was positively associated with functional connectivity of the bilateral dorsolateral prefrontal cortices, dorsal premotor cortices, and presupplementary areas. The effects were significant when controlling for hours of classical piano practice and age. These results indicate that even neural mechanisms involved in creative behaviors, which require a flexible online generation of novel and meaningful output, can be automated by training. Second, improvisational musical training can influence functional brain properties at a network level. We show that the greater functional connectivity seen in experienced improvisers may reflect a more efficient exchange of information within associative networks of importance for musical creativity.

Imaging the Where and When of Tic Generation and Resting State Networks in Adult Tourette Patients

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Irene eNeuner

2014-05-01

Full Text Available Introduction: Tourette syndrome (TS is a neuropsychiatric disorder with the core phenomenon of tics, whose origin and temporal pattern are unclear. We investigated the When and Where of tic generation and resting state networks (RSNs via functional magnetic resonance imaging (fMRI.Methods: Tic-related activity and the underlying resting state networks in adult TS were studied within one fMRI session. Participants were instructed to lie in the scanner and to let tics occur freely. Tic onset times, as determined by video-observance were used as regressors and added to preceding time-bins of one second duration each to detect prior activation. RSN were identified by independent component analysis (ICA and correlated to disease severity by the means of dual regression.Results: Two seconds before a tic, the supplementary motor area (SMA, ventral primary motor cortex, primary sensorimotor cortex and parietal operculum exhibited activation; one second before a tic, the anterior cingulate, putamen, insula, amygdala, cerebellum and the extrastriatal-visual cortex exhibited activation; with tic-onset, the thalamus, central operculum, primary motor and somatosensory cortices exhibited activation. Analysis of resting state data resulted in 21 components including the so-called default-mode network. Network strength in those regions in SMA of two premotor ICA maps that were also active prior to tic occurrence, correlated significantly with disease severity according to the Yale Global Tic Severity Scale (YGTTS scores.Discussion: We demonstrate that the temporal pattern of tic generation follows the cortico-striato-thalamo-cortical circuit, and that cortical structures precede subcortical activation. The analysis of spontaneous fluctuations highlights the role of cortical premotor structures. Our study corroborates the notion of TS as a network disorder in which abnormal resting state network activity might contribute to the generation of tics in SMA.

Imaging the where and when of tic generation and resting state networks in adult Tourette patients

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Neuner, Irene; Werner, Cornelius J.; Arrubla, Jorge; Stöcker, Tony; Ehlen, Corinna; Wegener, Hans P.; Schneider, Frank; Shah, N. Jon

2014-01-01

Introduction: Tourette syndrome (TS) is a neuropsychiatric disorder with the core phenomenon of tics, whose origin and temporal pattern are unclear. We investigated the When and Where of tic generation and resting state networks (RSNs) via functional magnetic resonance imaging (fMRI). Methods: Tic-related activity and the underlying RSNs in adult TS were studied within one fMRI session. Participants were instructed to lie in the scanner and to let tics occur freely. Tic onset times, as determined by video-observance were used as regressors and added to preceding time-bins of 1 s duration each to detect prior activation. RSN were identified by independent component analysis (ICA) and correlated to disease severity by the means of dual regression. Results: Two seconds before a tic, the supplementary motor area (SMA), ventral primary motor cortex, primary sensorimotor cortex and parietal operculum exhibited activation; 1 s before a tic, the anterior cingulate, putamen, insula, amygdala, cerebellum and the extrastriatal-visual cortex exhibited activation; with tic-onset, the thalamus, central operculum, primary motor and somatosensory cortices exhibited activation. Analysis of resting state data resulted in 21 components including the so-called default-mode network. Network strength in those regions in SMA of two premotor ICA maps that were also active prior to tic occurrence, correlated significantly with disease severity according to the Yale Global Tic Severity Scale (YGTTS) scores. Discussion: We demonstrate that the temporal pattern of tic generation follows the cortico-striato-thalamo-cortical circuit, and that cortical structures precede subcortical activation. The analysis of spontaneous fluctuations highlights the role of cortical premotor structures. Our study corroborates the notion of TS as a network disorder in which abnormal RSN activity might contribute to the generation of tics in SMA. PMID:24904391

Exploring the neural correlates of visual creativity

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Liew, Sook-Lei; Dandekar, Francesco

2013-01-01

Although creativity has been called the most important of all human resources, its neural basis is still unclear. In the current study, we used fMRI to measure neural activity in participants solving a visuospatial creativity problem that involves divergent thinking and has been considered a canonical right hemisphere task. As hypothesized, both the visual creativity task and the control task as compared to rest activated a variety of areas including the posterior parietal cortex bilaterally and motor regions, which are known to be involved in visuospatial rotation of objects. However, directly comparing the two tasks indicated that the creative task more strongly activated left hemisphere regions including the posterior parietal cortex, the premotor cortex, dorsolateral prefrontal cortex (DLPFC) and the medial PFC. These results demonstrate that even in a task that is specialized to the right hemisphere, robust parallel activity in the left hemisphere supports creative processing. Furthermore, the results support the notion that higher motor planning may be a general component of creative improvisation and that such goal-directed planning of novel solutions may be organized top-down by the left DLPFC and by working memory processing in the medial prefrontal cortex. PMID:22349801

Where one hand meets the other: limb-specific and action-dependent movement plans decoded from preparatory signals in single human frontoparietal brain areas.

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Gallivan, Jason P; McLean, D Adam; Flanagan, J Randall; Culham, Jody C

2013-01-30

Planning object-directed hand actions requires successful integration of the movement goal with the acting limb. Exactly where and how this sensorimotor integration occurs in the brain has been studied extensively with neurophysiological recordings in nonhuman primates, yet to date, because of limitations of non-invasive methodologies, the ability to examine the same types of planning-related signals in humans has been challenging. Here we show, using a multivoxel pattern analysis of functional MRI (fMRI) data, that the preparatory activity patterns in several frontoparietal brain regions can be used to predict both the limb used and hand action performed in an upcoming movement. Participants performed an event-related delayed movement task whereby they planned and executed grasp or reach actions with either their left or right hand toward a single target object. We found that, although the majority of frontoparietal areas represented hand actions (grasping vs reaching) for the contralateral limb, several areas additionally coded hand actions for the ipsilateral limb. Notable among these were subregions within the posterior parietal cortex (PPC), dorsal premotor cortex (PMd), ventral premotor cortex, dorsolateral prefrontal cortex, presupplementary motor area, and motor cortex, a region more traditionally implicated in contralateral movement generation. Additional analyses suggest that hand actions are represented independently of the intended limb in PPC and PMd. In addition to providing a unique mapping of limb-specific and action-dependent intention-related signals across the human cortical motor system, these findings uncover a much stronger representation of the ipsilateral limb than expected from previous fMRI findings.

TMS-induced neural noise in sensory cortex interferes with short-term memory storage in prefrontal cortex.

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Bancroft, Tyler D; Hogeveen, Jeremy; Hockley, William E; Servos, Philip

2014-01-01

In a previous study, Harris et al. (2002) found disruption of vibrotactile short-term memory after applying single-pulse transcranial magnetic stimulation (TMS) to primary somatosensory cortex (SI) early in the maintenance period, and suggested that this demonstrated a role for SI in vibrotactile memory storage. While such a role is compatible with recent suggestions that sensory cortex is the storage substrate for working memory, it stands in contrast to a relatively large body of evidence from human EEG and single-cell recording in primates that instead points to prefrontal cortex as the storage substrate for vibrotactile memory. In the present study, we use computational methods to demonstrate how Harris et al.'s results can be reproduced by TMS-induced activity in sensory cortex and subsequent feedforward interference with memory traces stored in prefrontal cortex, thereby reconciling discordant findings in the tactile memory literature.

Distributed patterns of activity in sensory cortex reflect the precision of multiple items maintained in visual short-term memory.

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Emrich, Stephen M; Riggall, Adam C; Larocque, Joshua J; Postle, Bradley R

2013-04-10

Traditionally, load sensitivity of sustained, elevated activity has been taken as an index of storage for a limited number of items in visual short-term memory (VSTM). Recently, studies have demonstrated that the contents of a single item held in VSTM can be decoded from early visual cortex, despite the fact that these areas do not exhibit elevated, sustained activity. It is unknown, however, whether the patterns of neural activity decoded from sensory cortex change as a function of load, as one would expect from a region storing multiple representations. Here, we use multivoxel pattern analysis to examine the neural representations of VSTM in humans across multiple memory loads. In an important extension of previous findings, our results demonstrate that the contents of VSTM can be decoded from areas that exhibit a transient response to visual stimuli, but not from regions that exhibit elevated, sustained load-sensitive delay-period activity. Moreover, the neural information present in these transiently activated areas decreases significantly with increasing load, indicating load sensitivity of the patterns of activity that support VSTM maintenance. Importantly, the decrease in classification performance as a function of load is correlated with within-subject changes in mnemonic resolution. These findings indicate that distributed patterns of neural activity in putatively sensory visual cortex support the representation and precision of information in VSTM.

Biphasic activation of the mTOR pathway in the gustatory cortex is correlated with and necessary for taste learning.

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Belelovsky, Katya; Kaphzan, Hanoch; Elkobi, Alina; Rosenblum, Kobi

2009-06-10

Different forms of memories and synaptic plasticity require synthesis of new proteins at the time of acquisition or immediately after. We are interested in the role of translation regulation in the cortex, the brain structure assumed to store long-term memories. The mammalian target of rapamycin, mTOR (also known as FRAP and RAFT-1), is part of a key signal transduction mechanism known to regulate translation of specific subset of mRNAs and to affect learning and synaptic plasticity. We report here that novel taste learning induces two waves of mTOR activation in the gustatory cortex. Interestingly, the first wave can be identified both in synaptoneurosomal and cellular fractions, whereas the second wave is detected in the cellular fraction but not in the synaptic one. Inhibition of mTOR, specifically in the gustatory cortex, has two effects. First, biochemically, it modulates several known downstream proteins that control translation and reduces the expression of postsynaptic density-95 in vivo. Second, behaviorally, it attenuates long-term taste memory. The results suggest that the mTOR pathway in the cortex modulates both translation factor activity and protein expression, to enable normal taste memory consolidation.

The Effects of rTMS Combined with Motor Training on Functional Connectivity in Alpha Frequency Band.

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Jin, Jing-Na; Wang, Xin; Li, Ying; Jin, Fang; Liu, Zhi-Peng; Yin, Tao

2017-01-01

It has recently been reported that repetitive transcranial magnetic stimulation combined with motor training (rTMS-MT) could improve motor function in post-stroke patients. However, the effects of rTMS-MT on cortical function using functional connectivity and graph theoretical analysis remain unclear. Ten healthy subjects were recruited to receive rTMS immediately before application of MT. Low frequency rTMS was delivered to the dominant hemisphere and non-dominant hand performed MT over 14 days. The reaction time of Nine-Hole Peg Test and electroencephalography (EEG) in resting condition with eyes closed were recorded before and after rTMS-MT. Functional connectivity was assessed by phase synchronization index (PSI), and subsequently thresholded to construct undirected graphs in alpha frequency band (8-13 Hz). We found a significant decrease in reaction time after rTMS-MT. The functional connectivity between the parietal and frontal cortex, and the graph theory statistics of node degree and efficiency in the parietal cortex increased. Besides the functional connectivity between premotor and frontal cortex, the degree and efficiency of premotor cortex showed opposite results. In addition, the number of connections significantly increased within inter-hemispheres and inter-regions. In conclusion, this study could be helpful in our understanding of how rTMS-MT modulates brain activity. The methods and results in this study could be taken as reference in future studies of the effects of rTMS-MT in stroke patients.

Activity in prelimbic cortex is required for adjusting the anxiety response level during the elevated plus-maze retest.

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Stern, C A J; Do Monte, F H M; Gazarini, L; Carobrez, A P; Bertoglio, L J

2010-09-29

The prelimbic (PL) subregion of medial prefrontal cortex has been implicated in anxiety regulation. It is unknown, however, whether PL cortex also serves to fine-tuning the level of anxiety-related behavior exhibited on the next exposure to the same potentially threatening situation. To address this, we infused cobalt (1.0 mM) to temporarily inactivate the PL cortex during testing, post-testing or retesting in the elevated plus-maze (EPM). This protocol was chosen because it allowed us to concurrently investigate anxiety and the process of aversive learning and memory. PL cortex inactivation during the EPM testing increased the exploration of open-arms, substantiating its role in anxiety. PL cortex inactivation during the EPM retesting counteracted the further avoidance to open-arms exhibited by rats. Interestingly, as evidenced by min-by-min analysis, the cobalt-treated group behaved on EPM retesting as did the vehicle-treated group on EPM testing. This result may imply that activity in PL cortex is necessary for retrieving previously learned information that adjusts the anxiety response level on EPM retesting. Alternatively, a simple reduction in anxiety could explain the cobalt-induced increase in retest open-arms exploration. Neither test nor post-test PL cortex inactivation affected the further avoidance to open-arms observed on EPM retesting. To extend the investigation of PL cortex role in the regulation of open-arms avoidance, we infused other drugs prior to testing or retesting in the EPM. Antagonism of PL cortex adrenergic beta-1 receptors with atenolol (10 nmol), cholinergic muscarinic receptors with scopolamine (20 nmol) or glutamatergic N-methyl-d-aspartic acid (NMDA) receptors with AP5 (6.0 nmol) interfered with the level of open-arms exploration on testing, but not on retesting. Copyright 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

Pedophilia is linked to reduced activation in hypothalamus and lateral prefrontal cortex during visual erotic stimulation.

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Walter, Martin; Witzel, Joachim; Wiebking, Christine; Gubka, Udo; Rotte, Michael; Schiltz, Kolja; Bermpohl, Felix; Tempelmann, Claus; Bogerts, Bernhard; Heinze, Hans Jochen; Northoff, Georg

2007-09-15

Although pedophilia is of high public concern, little is known about underlying neural mechanisms. Although pedophilic patients are sexually attracted to prepubescent children, they show no sexual interest toward adults. This study aimed to investigate the neural correlates of deficits of sexual and emotional arousal in pedophiles. Thirteen pedophilic patients and 14 healthy control subjects were tested for differential neural activity during visual stimulation with emotional and erotic pictures with functional magnetic resonance imaging. Regions showing differential activations during the erotic condition comprised the hypothalamus, the periaqueductal gray, and dorsolateral prefrontal cortex, the latter correlating with a clinical measure. Alterations of emotional processing concerned the amygdala-hippocampus and dorsomedial prefrontal cortex. Hypothesized regions relevant for processing of erotic stimuli in healthy individuals showed reduced activations during visual erotic stimulation in pedophilic patients. This suggests an impaired recruitment of key structures that might contribute to an altered sexual interest of these patients toward adults.

Acute caffeine administration effect on brain activation patterns in mild cognitive impairment.

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Haller, Sven; Montandon, Marie-Louise; Rodriguez, Cristelle; Moser, Dominik; Toma, Simona; Hofmeister, Jeremy; Sinanaj, Indrit; Lovblad, Karl-Olof; Giannakopoulos, Panteleimon

2014-01-01

Previous studies showed that acute caffeine administration enhances task-related brain activation in elderly individuals with preserved cognition. To explore the effects of this widely used agent on cognition and brain activation in early phases of cognitive decline, we performed a double-blinded, placebo-controlled functional magnetic resonance imaging (fMRI) study during an n-back working memory task in 17 individuals with mild cognitive impairment (MCI) compared to 17 age-matched healthy controls (HC). All individuals were regular caffeine consumers with an overnight abstinence and given 200 mg caffeine versus placebo tablets 30 minutes before testing. Analyses included assessment of task-related activation (general linear model), functional connectivity (tensorial-independent component analysis, TICA), baseline perfusion (arterial spin labeling, ASL), grey matter density (voxel-based morphometry, VBM), and white matter microstructure (tract-based spatial statistics, TBSS). Acute caffeine administration induced a focal activation of the prefrontal areas in HC with a more diffuse and posteromedial activation pattern in MCI individuals. In MCI, TICA documented a significant caffeine-related enhancement in the prefrontal cortex, supplementary motor area, ventral premotor and parietal cortex as well as the basal ganglia and cerebellum. The absence of significant group differences in baseline ASL perfusion patterns supports a neuronal rather than a purely vascular origin of these differences. The VBM and TBSS analyses excluded potentially confounding differences in grey matter density and white matter microstructure between MCI and HC. The present findings suggest a posterior displacement of working memory-related brain activation patterns after caffeine administration in MCI that may represent a compensatory mechanism to counterbalance a frontal lobe dysfunction.

Shape perception simultaneously up- and downregulates neural activity in the primary visual cortex.

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Kok, Peter; de Lange, Floris P

2014-07-07

An essential part of visual perception is the grouping of local elements (such as edges and lines) into coherent shapes. Previous studies have shown that this grouping process modulates neural activity in the primary visual cortex (V1) that is signaling the local elements [1-4]. However, the nature of this modulation is controversial. Some studies find that shape perception reduces neural activity in V1 [2, 5, 6], while others report increased V1 activity during shape perception [1, 3, 4, 7-10]. Neurocomputational theories that cast perception as a generative process [11-13] propose that feedback connections carry predictions (i.e., the generative model), while feedforward connections signal the mismatch between top-down predictions and bottom-up inputs. Within this framework, the effect of feedback on early visual cortex may be either enhancing or suppressive, depending on whether the feedback signal is met by congruent bottom-up input. Here, we tested this hypothesis by quantifying the spatial profile of neural activity in V1 during the perception of illusory shapes using population receptive field mapping. We find that shape perception concurrently increases neural activity in regions of V1 that have a receptive field on the shape but do not receive bottom-up input and suppresses activity in regions of V1 that receive bottom-up input that is predicted by the shape. These effects were not modulated by task requirements. Together, these findings suggest that shape perception changes lower-order sensory representations in a highly specific and automatic manner, in line with theories that cast perception in terms of hierarchical generative models. Copyright © 2014 Elsevier Ltd. All rights reserved.

Synaptic input correlations leading to membrane potential decorrelation of spontaneous activity in cortex.

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Graupner, Michael; Reyes, Alex D

2013-09-18

Correlations in the spiking activity of neurons have been found in many regions of the cortex under multiple experimental conditions and are postulated to have important consequences for neural population coding. While there is a large body of extracellular data reporting correlations of various strengths, the subthreshold events underlying the origin and magnitude of signal-independent correlations (called noise or spike count correlations) are unknown. Here we investigate, using intracellular recordings, how synaptic input correlations from shared presynaptic neurons translate into membrane potential and spike-output correlations. Using a pharmacologically activated thalamocortical slice preparation, we perform simultaneous recordings from pairs of layer IV neurons in the auditory cortex of mice and measure synaptic potentials/currents, membrane potentials, and spiking outputs. We calculate cross-correlations between excitatory and inhibitory inputs to investigate correlations emerging from the network. We furthermore evaluate membrane potential correlations near resting potential to study how excitation and inhibition combine and affect spike-output correlations. We demonstrate directly that excitation is correlated with inhibition thereby partially canceling each other and resulting in weak membrane potential and spiking correlations between neurons. Our data suggest that cortical networks are set up to partially cancel correlations emerging from the connections between neurons. This active decorrelation is achieved because excitation and inhibition closely track each other. Our results suggest that the numerous shared presynaptic inputs do not automatically lead to increased spiking correlations.

Neural Correlates of Expert Visuomotor Performance in Badminton Players.

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Hülsdünker, Thorben; Strüder, Heiko K; Mierau, Andreas

2016-11-01

Elite/skilled athletes participating in sports that require the initiation of targeted movements in response to visual cues under critical time pressure typically outperform nonathletes in a visuomotor reaction task. However, the exact physiological mechanisms of this advantage remain unclear. Therefore, this study aimed to determine the neurophysiological processes contributing to superior visuomotor performance in athletes using visual evoked potential (VEP). Central and peripheral determinants of visuomotor reaction time were investigated in 15 skilled badminton players and 28 age-matched nonathletic controls. To determine the speed of visual signal perception in the cortex, chromatic and achromatic pattern reversal stimuli were presented, and VEP values were recorded with a 64-channel EEG system. Further, a simple visuomotor reaction task was performed to investigate the transformation of the visual into a motor signal in the brain as well as the timing of muscular activation. Amplitude and latency of VEP (N75, P100, and N145) revealed that the athletes did not significantly differ from the nonathletes. However, visuomotor reaction time was significantly reduced in the athletes compared with nonathletes (athletes = 234.9 ms, nonathletes = 260.3 ms, P = 0.015). This was accompanied by an earlier activation of the premotor and supplementary motor areas (athletes = 163.9 ms, nonathletes = 199.1 ms, P = 0.015) as well as an earlier EMG onset (athletes = 167.5 ms, nonathletes = 206.5 ms, P < 0.001). The latency of premotor and supplementary motor area activation was correlated with EMG onset (r = 0.41) and visuomotor reaction time (r = 0.43). The results of this study indicate that superior visuomotor performance in athletes originates from faster visuomotor transformation in the premotor and supplementary motor cortical regions rather than from earlier perception of visual signals in the visual cortex.

The effect of breakfast versus no breakfast on brain activity in adolescents when performing cognitive tasks, as assessed by fMRI.

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Fulford, Jonathan; Varley-Campbell, Joanna L; Williams, Craig A

2016-01-01

The study examined the feasibility of utilizing functional magnetic resonance imaging (fMRI) with a group of adolescent boys and girls to assess modifications in cognitive function, dependent upon the nutritional state of the participants. Twenty children aged 12-14 years completed two cognitive trials, in a randomized counterbalanced order, one under fasting condition, one after consuming breakfast, during which continuous fMRI data were acquired. Although no statistically significant (P > 0.05) improvement in task performance was determined, significantly higher activation was recorded in the frontal, premotor, and primary visual cortex areas in the breakfast trial relative to the fasting condition. Such a finding may have important implications in the examination of the role of diet, and specifically breakfast, in determining children's performance within the school environment.

Early (N170) activation of face-specific cortex by face-like objects

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Hadjikhani, Nouchine; Kveraga, Kestutis; Naik, Paulami; Ahlfors, Seppo P.

2009-01-01

The tendency to perceive faces in random patterns exhibiting configural properties of faces is an example of pareidolia. Perception of ‘real’ faces has been associated with a cortical response signal arising at about 170ms after stimulus onset; but what happens when non-face objects are perceived as faces? Using magnetoencephalography (MEG), we found that objects incidentally perceived as faces evoked an early (165ms) activation in the ventral fusiform cortex, at a time and location similar t...

Activation of the Prefrontal Cortex While Performing a Task at Preferred Slow Pace and Metronome Slow Pace: A Functional Near-Infrared Spectroscopy Study

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Kaori Shimoda

2014-01-01

Full Text Available Individuals have a preferred pace at which they perform voluntary repetitive movements. Previous studies have reported that greater activation of the prefrontal cortex was observed during self-initiated movements than during externally triggered movements. The purpose of the present study is to compare the activation of the prefrontal cortex induced when the subjects performed a peg-board task at their preferred slow pace (PSP, the self-initiated condition with that induced when they performed the same task at metronome slow pace (MSP, the externally triggered condition using functional near-infrared spectroscopy. Healthy subjects performed the task while sitting in a chair. By assessing the activated channels individually, we confirmed that all of the prefrontal regions of interest were activated by both tasks. In the second-level analyses, we found that the activation detected in the frontopolar cortex (FPPFC; Brodmann area 10 was higher during the PSP task than during the MSP task. The FPPFC is known to be at the top of prefrontal hierarchy, and specifically involved in evaluating self-generated information. In addition, the FPPFC plays a role in coordinating lateral prefrontal cortex. In the present study, the subjects evaluated and managed the internally generated PSP by coordinating the activity of other lower level prefrontal regions.

Activation of the prefrontal cortex while performing a task at preferred slow pace and metronome slow pace: a functional near-infrared spectroscopy study.

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Shimoda, Kaori; Moriguchi, Yoshiya; Tsuchiya, Kenji; Katsuyama, Shiori; Tozato, Fusae

2014-01-01

Individuals have a preferred pace at which they perform voluntary repetitive movements. Previous studies have reported that greater activation of the prefrontal cortex was observed during self-initiated movements than during externally triggered movements. The purpose of the present study is to compare the activation of the prefrontal cortex induced when the subjects performed a peg-board task at their preferred slow pace (PSP, the self-initiated condition) with that induced when they performed the same task at metronome slow pace (MSP, the externally triggered condition) using functional near-infrared spectroscopy. Healthy subjects performed the task while sitting in a chair. By assessing the activated channels individually, we confirmed that all of the prefrontal regions of interest were activated by both tasks. In the second-level analyses, we found that the activation detected in the frontopolar cortex (FPPFC; Brodmann area 10) was higher during the PSP task than during the MSP task. The FPPFC is known to be at the top of prefrontal hierarchy, and specifically involved in evaluating self-generated information. In addition, the FPPFC plays a role in coordinating lateral prefrontal cortex. In the present study, the subjects evaluated and managed the internally generated PSP by coordinating the activity of other lower level prefrontal regions.

Relational complexity modulates activity in the prefrontal cortex during numerical inductive reasoning: an fMRI study.

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Feng, Xiao; Peng, Li; Chang-Quan, Long; Yi, Lei; Hong, Li

2014-09-01

Most previous studies investigating relational reasoning have used visuo-spatial materials. This fMRI study aimed to determine how relational complexity affects brain activity during inductive reasoning, using numerical materials. Three numerical relational levels of the number series completion task were adopted for use: 0-relational (e.g., "23 23 23"), 1-relational ("32 30 28") and 2-relational ("12 13 15") problems. The fMRI results revealed that the bilateral dorsolateral prefrontal cortex (DLPFC) showed enhanced activity associated with relational complexity. Bilateral inferior parietal lobule (IPL) activity was greater during the 1- and 2-relational level problems than during the 0-relational level problems. In addition, the left fronto-polar cortex (FPC) showed selective activity during the 2-relational level problems. The bilateral DLPFC may be involved in the process of hypothesis generation, whereas the bilateral IPL may be sensitive to calculation demands. Moreover, the sensitivity of the left FPC to the multiple relational problems may be related to the integration of numerical relations. The present study extends our knowledge of the prefrontal activity pattern underlying numerical relational processing. Copyright © 2014 Elsevier B.V. All rights reserved.

Activation of right parietal cortex during memory retrieval of nonlinguistic auditory stimuli.

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Klostermann, Ellen C; Loui, Psyche; Shimamura, Arthur P

2009-09-01

In neuroimaging studies, the left ventral posterior parietal cortex (PPC) is particularly active during memory retrieval. However, most studies have used verbal or verbalizable stimuli. We investigated neural activations associated with the retrieval of short, agrammatical music stimuli (Blackwood, 2004), which have been largely associated with right hemisphere processing. At study, participants listened to music stimuli and rated them on pleasantness. At test, participants made old/new recognition judgments with high/low confidence ratings. Right, but not left, ventral PPC activity was observed during the retrieval of these music stimuli. Thus, rather than indicating a special status of left PPC in retrieval, both right and left ventral PPC participate in memory retrieval, depending on the type of information that is to be remembered.

Peripheral nerve injury induces glial activation in primary motor cortex

OpenAIRE

Julieta Troncoso; Julieta Troncoso; Efraín Buriticá; Efraín Buriticá

2015-01-01

Preliminary evidence suggests that peripheral facial nerve injuries are associated with sensorimotor cortex reorganization. We have characterized facial nerve lesion-induced structural changes in primary motor cortex layer 5 pyramidal neurons and their relationship with glial cell density using a rodent facial paralysis model. First, we used adult transgenic mice expressing green fluorescent protein in microglia and yellow fluorescent protein in pyramidal neurons which were subjected to eithe...

Functional magnetic resonance imaging (fMRI) in patients with gliomas adjacent to classical language areas. Lateralization of activated prefrontal cortex is important in determining the dominant hemisphere

International Nuclear Information System (INIS)

Karibe, Hiroshi; Kumabe, Toshihiro; Shirane, Reizo; Yoshimoto, Takashi

2003-01-01

In patients with gliomas adjacent to classical language areas, lateralized activation of prefrontal cortex was assessed to determine language dominant hemisphere using functional magnetic resonance imaging (fMRI). Twelve patients presented with aphasias were studied. In all patients, either the left frontal operculum or left superior temporal gyri were adjacent to gliomas, suggesting all patients had left lateralization in hemispheric language dominance. Functional MRI was performed with a 1.5T scanner, with the sequence of gradient-echo type echo-planar imaging. As specific language tasks, verb, word, and capping generations were used. Using a cross-correlation analysis method, primary activation maps were generated using pixels with a correlation coefficient of >0.7. The lateralized activation of frontal operculum, superior temporal gyrus, and prefrontal cortex were assessed by calculating laterality index. Successful activation of frontal operculum was imaged in 11 of 12, in the superior temporal gyrus or prefrontal cortex. Three out of 11 cases had apparent activation lateralized in the right frontal operculum on fMRI, while 3 out of 12 cases showed activation in the superior temporal gyrus. On the other hand, all cases had apparent activation lateralized to the left prefrontal cortex. Significant activation of true language area may not be obtained in some cases with gliomas adjacent to classical language areas. In such cases, lateralization of apparent activation of prefrontal cortex may reflect lateralization in the dominant hemisphere. These result suggest that the assessment of apparent activation of prefrontal cortex lateralization is useful to determine the language dominant hemisphere. (author)

Maps of space in human frontoparietal cortex.

Science.gov (United States)

Jerde, Trenton A; Curtis, Clayton E

2013-12-01

Prefrontal cortex (PFC) and posterior parietal cortex (PPC) are neural substrates for spatial cognition. We here review studies in which we tested the hypothesis that human frontoparietal cortex may function as a priority map. According to priority map theory, objects or locations in the visual world are represented by neural activity that is proportional to their attentional priority. Using functional magnetic resonance imaging (fMRI), we first identified topographic maps in PFC and PPC as candidate priority maps of space. We then measured fMRI activity in candidate priority maps during the delay periods of a covert attention task, a spatial working memory task, and a motor planning task to test whether the activity depended on the particular spatial cognition. Our hypothesis was that some, but not all, candidate priority maps in PFC and PPC would be agnostic with regard to what was being prioritized, in that their activity would reflect the location in space across tasks rather than a particular kind of spatial cognition (e.g., covert attention). To test whether patterns of delay period activity were interchangeable during the spatial cognitive tasks, we used multivariate classifiers. We found that decoders trained to predict the locations on one task (e.g., working memory) cross-predicted the locations on the other tasks (e.g., covert attention and motor planning) in superior precentral sulcus (sPCS) and in a region of intraparietal sulcus (IPS2), suggesting that these patterns of maintenance activity may be interchangeable across the tasks. Such properties make sPCS in frontal cortex and IPS2 in parietal cortex viable priority map candidates, and suggest that these areas may be the human homologs of the monkey frontal eye field (FEF) and lateral intraparietal area (LIP). Copyright © 2013 Elsevier Ltd. All rights reserved.

Differential expression of secreted phosphoprotein 1 in the motor cortex among primate species and during postnatal development and functional recovery.

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Tatsuya Yamamoto

Full Text Available We previously reported that secreted phosphoprotein 1 (SPP1 mRNA is expressed in neurons whose axons form the corticospinal tract (CST of the rhesus macaque, but not in the corresponding neurons of the marmoset and rat. This suggests that SPP1 expression is involved in the functional or structural specialization of highly developed corticospinal systems in certain primate species. To further examine this hypothesis, we evaluated the expression of SPP1 mRNA in the motor cortex from three viewpoints: species differences, postnatal development, and functional/structural changes of the CST after a lesion of the lateral CST (l-CST at the mid-cervical level. The density of SPP1-positive neurons in layer V of the primary motor cortex (M1 was much greater in species with highly developed corticospinal systems (i.e., rhesus macaque, capuchin monkey, and humans than in those with less developed corticospinal systems (i.e., squirrel monkey, marmoset, and rat. SPP1-positive neurons in the macaque monkey M1 increased logarithmically in layer V during postnatal development, following a time course consistent with the increase in conduction velocity of the CST. After an l-CST lesion, SPP1-positive neurons increased in layer V of the ventral premotor cortex, in which compensatory changes in CST function/structure may occur, which positively correlated with the extent of finger dexterity recovery. These results further support the concept that the expression of SPP1 may reflect functional or structural specialization of highly developed corticospinal systems in certain primate species.

Functional magnetic resonance imaging study comparing rhythmic finger tapping in children and adults.

Science.gov (United States)

De Guio, François; Jacobson, Sandra W; Molteno, Christopher D; Jacobson, Joseph L; Meintjes, Ernesta M

2012-02-01

This study compared brain activation during unpaced rhythmic finger tapping in 12-year-old children with that of adults. Subjects pressed a button at a pace initially indicated by a metronome (12 consecutive tones), and then continued for 16 seconds of unpaced tapping to provide an assessment of their ability to maintain a steady rhythm. These analyses focused on the superior vermis of the cerebellum, which is known to play a key role in timing. Twelve adults and 12 children performed this rhythmic finger tapping task in a 3 T scanner. Whole-brain analyses were performed in Brain Voyager, with a random-effects analysis of variance using a general linear model. A dedicated cerebellar atlas was used to localize cerebellar activations. As in adults, unpaced rhythmic finger tapping in children demonstrated activations in the primary motor cortex, premotor cortex, and cerebellum. However, overall activation was different, in that adults demonstrated much more deactivation in response to the task, particularly in the occipital and frontal cortices. The other main differences involved the additional recruitment of motor and premotor areas in children compared with adults, and increased activity in the vermal region of the cerebellum. These findings suggest that the timing component of the unpaced rhythmic finger tapping task is less efficient and automatic in children, who need to recruit the superior vermis more intensively to maintain the rhythm, although they performed somewhat more poorly than adults. Copyright © 2012 Elsevier Inc. All rights reserved.

Visuomotor Dissociation in Cerebral Scaling of Size.

Science.gov (United States)

Potgieser, Adriaan R E; de Jong, Bauke M

2016-01-01

Estimating size and distance is crucial in effective visuomotor control. The concept of an internal coordinate system implies that visual and motor size parameters are scaled onto a common template. To dissociate perceptual and motor components in such scaling, we performed an fMRI experiment in which 16 right-handed subjects copied geometric figures while the result of drawing remained out of sight. Either the size of the example figure varied while maintaining a constant size of drawing (visual incongruity) or the size of the examples remained constant while subjects were instructed to make changes in size (motor incongruity). These incongruent were compared to congruent conditions. Statistical Parametric Mapping (SPM8) revealed brain activations related to size incongruity in the dorsolateral prefrontal and inferior parietal cortex, pre-SMA / anterior cingulate and anterior insula, dominant in the right hemisphere. This pattern represented simultaneous use of a 'resized' virtual template and actual picture information requiring spatial working memory, early-stage attention shifting and inhibitory control. Activations were strongest in motor incongruity while right pre-dorsal premotor activation specifically occurred in this condition. Visual incongruity additionally relied on a ventral visual pathway. Left ventral premotor activation occurred in all variably sized drawing while constant visuomotor size, compared to congruent size variation, uniquely activated the lateral occipital cortex additional to superior parietal regions. These results highlight size as a fundamental parameter in both general hand movement and movement guided by objects perceived in the context of surrounding 3D space.

Modality-specific involvement of occipital cortex in Early Blind?

NARCIS (Netherlands)

van der Lubbe, Robert Henricus Johannes; van Mierlo, C.M.; Postma, A.

2008-01-01

What happens in occipital cortex when neuronal activity is no longer evoked by regular visual stimulation? Studying brain activity induced by tactile and auditory stimuli in the blind may provide an answer. Several studies indicate that occipital cortex in the blind is recruited in simple tasks,

[CHANGES IN THE NUMBER OF NEURONS IN THE MOTOR CORTEX OF RATS AND THEIR LOCOMOTOR ACTIVITY IN THE AGE ASPECT].

Science.gov (United States)

Piavchenko, G A; Shmarkova, L I; Nozdrin, V I

2015-01-01

Using Laboras hardware-software complex, which is a system of automatic registration of behavioral reactions, the locomotor activity 1-, 8- and 16-month-old male rats (12 animals in each group) was recorded followed by counting the number of neuron cell bodies of in the layer V of the motor cortex in Nissl stained slides. It was found that the number of neurons in the motor cortex varied in different age groups. Maximal number of neurons was observed in 8-month-old animals. Motor activity was found to correlate with the number of neurons.

Our Faces in the Dog's Brain: Functional Imaging Reveals Temporal Cortex Activation during Perception of Human Faces.

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Laura V Cuaya

Full Text Available Dogs have a rich social relationship with humans. One fundamental aspect of it is how dogs pay close attention to human faces in order to guide their behavior, for example, by recognizing their owner and his/her emotional state using visual cues. It is well known that humans have specific brain regions for the processing of other human faces, yet it is unclear how dogs' brains process human faces. For this reason, our study focuses on describing the brain correlates of perception of human faces in dogs using functional magnetic resonance imaging (fMRI. We trained seven domestic dogs to remain awake, still and unrestrained inside an MRI scanner. We used a visual stimulation paradigm with block design to compare activity elicited by human faces against everyday objects. Brain activity related to the perception of faces changed significantly in several brain regions, but mainly in the bilateral temporal cortex. The opposite contrast (i.e., everyday objects against human faces showed no significant brain activity change. The temporal cortex is part of the ventral visual pathway, and our results are consistent with reports in other species like primates and sheep, that suggest a high degree of evolutionary conservation of this pathway for face processing. This study introduces the temporal cortex as candidate to process human faces, a pillar of social cognition in dogs.

Evidence of a Christmas spirit network in the brain

DEFF Research Database (Denmark)

Hougaard, Anders; Lindberg, Ulrich; Arngrim, Nanna

2015-01-01

OBJECTIVE: To detect and localise the Christmas spirit in the human brain. DESIGN: Single blinded, cross cultural group study with functional magnetic resonance imaging (fMRI). SETTING: Functional imaging unit and department of clinical physiology, nuclear medicine and PET in Denmark. PARTICIPANTS......: 10 healthy people from the Copenhagen area who routinely celebrate Christmas and 10 healthy people living in the same area who have no Christmas traditions. MAIN OUTCOME MEASURES: Brain activation unique to the group with Christmas traditions during visual stimulation with images with a Christmas......, differences between the two groups were calculated to determine Christmas specific brain activation. RESULTS: Significant clusters of increased BOLD activation in the sensory motor cortex, the premotor and primary motor cortex, and the parietal lobule (inferior and superior) were found in scans of people who...

Brain regions involved in voluntary movements as revealed by radioisotopic mapping of CBF or CMR-glucose changes

DEFF Research Database (Denmark)

Lassen, N A; Ingvar, D H

1990-01-01

Mapping of cortical and subcortical grey matter active during voluntary movements by means of measurements of local increases of CBF or CMR-Glucose is reviewed. Most of the studies concern observations in man during hand movements using the intracarotid Xenon-133 injection technique, an approach...... that only allows to image the cortex of the hemisphere on one side (the injected side) of the brain. The results show that simple static or repetitive movements mainly activate the contralateral primary hand area (MI and SI); complex preprogrammed or spontaneous purposeful movements the supplementary motor...... area SMA on both sides increase in CBF/CMR-glucose and even internally ("mentally") going through the trained movements, causes such changes; complex purposeful movements also activate the premotor cortex, a response that is bilateral with greatest response contralaterally. Studies in patients...

Comparative neuroimaging in children with cerebral palsy using fMRI and a novel EEG-based brain mapping during a motor task--a preliminary investigation.

Science.gov (United States)

Lee, Jae Jin; Lee, Dong Ryul; Shin, Yoon Kyum; Lee, Nam Gi; Han, Bong S; You, Sung Joshua Hyun

2013-01-01

The purpose of this study was to compare topographical maps using a novel EEG-based brain mapping system with fMRI in normal and children with cerebral palsy (CP) during a grasping motor task. A normal child (mean ± SD = 13 ± 0 yrs) and four children with CP (mean ± SD = 10.25 ± 2.86 yrs) were recruited from a local community school and medical center. A novel EEG-based brain mapping system with 30 scalp sites (an extension of the 10-20 system) and a 3T MR scanner were used to observe cortical activation patterns during a grasping motor task. Descriptive analysis. In the EEG brain mapping data, the sensorimotor cortex (SMC) and inferior parietal cortex (IPC) were activated in all of the children. The children with CP showed additional activation areas in the premotor cortex (PMC), superior parietal cortex (SPC), and prefrontal cortex (PFC). In the fMRI brain mapping data, SMC activation was observed in all of the children, and the children with CP showed additional activation areas in the PMC and primary somatosensory cortex (PSC). The EEG-based topographical maps were equivalent to the maps obtained from fMRI during the grasping motor task. The results indicate that our novel EEG-based brain mapping system is useful for probing cortical activation patterns in normal children and children with CP.

Object words modulate the activity of the mirror neuron system during action imitation.

Science.gov (United States)

Wu, Haiyan; Tang, Honghong; Ge, Yue; Yang, Suyong; Mai, Xiaoqin; Luo, Yue-Jia; Liu, Chao

2017-11-01

Although research has demonstrated that the mirror neuron system (MNS) plays a crucial role in both action imitation and action-related semantic processing, whether action-related words can inversely modulate the MNS activity remains unclear. Here, three types of task-irrelevant words (body parts, verbs, and manufactured objects) were presented to examine the modulation effect of these words on the MNS activity during action observation and imitation. Twenty-two participants were recruited for the fMRI scanning and remaining data from 19 subjects were reported here. Brain activity results showed that word types elicited different modulation effects over nodes of the MNS (i.e., the right inferior frontal gyrus, premotor cortex, inferior parietal lobule, and STS), especially during the imitation stage. Compared with other word conditions, action imitation following manufactured objects words induced stronger activation in these brain regions during the imitation stage. These results were consistent in both task-dependent and -independent ROI analysis. Our findings thus provide evidence for the unique effect of object words on the MNS during imitation of action, which may also confirm the key role of goal inference in action imitation.

Functional brain mapping using H215O positron emission tomography (II): mapping of human working memory

International Nuclear Information System (INIS)

Lee, Jae Sung; Lee, Dong Soo; Lee, Sang Kun; Nam, Hyun Woo; Kim, Seok Ki; Park, Kwang Suk; Jeong, Jae Min; Chung, June Key; Lee, Myung Chul

1998-01-01

To localize and compare the neural basis of verbal and visual human working memory, we performed functional activation study using H 2 15 O PET. Repeated H 2 15 O PET scans with one control and three different activation tasks were performed on six right-handed normal volunteers. Each activation task was composed of 13 matching trials. On each trial, four targets, a fixation dot and a prove were presented sequentially and subject's tasks was to press a response button to indicate whether or not the prove was one of the previous targets. Short meaningful Korean words, simple drawings and monochromic pictures of human faces were used as matching objects for verbal or visual memory. All the images were spatially normalized and the differences between control and activation states were statistically analyzed using SPM96. Statistical analysis of verbal memory activation with short words showed activation in the left Broca's area, premotor cortex, cerebellum and right cingulate gyrus. In verbal memory with simple drawing, activation was shown in the larger regions including where activated with short words and left superior temporal cortex, basal ganglia, thalamus, prefrontal cortex, anterior portion of right superior temporal gyrus and right infero-lateral frontal cortex. On the other hand, the visual memory task activated predominantly right-sided structures, especially inferior frontal cortex, supplementary motor cortex and superior parietal cortex. The results are consistent with the hypothesis of the laterality and dissociation of the verbal and visual working memory from the invasive electrophysiological studies and emphasize the pivotal role of frontal cortex and cingulate gyrus in working memory system

Engagement of the Rat Hindlimb Motor Cortex across Natural Locomotor Behaviors.

Science.gov (United States)

DiGiovanna, Jack; Dominici, Nadia; Friedli, Lucia; Rigosa, Jacopo; Duis, Simone; Kreider, Julie; Beauparlant, Janine; van den Brand, Rubia; Schieppati, Marco; Micera, Silvestro; Courtine, Grégoire

2016-10-05

Contrary to cats and primates, cortical contribution to hindlimb locomotor movements is not critical in rats. However, the importance of the motor cortex to regain locomotion after neurological disorders in rats suggests that cortical engagement in hindlimb motor control may depend on the behavioral context. To investigate this possibility, we recorded whole-body kinematics, muscle synergies, and hindlimb motor cortex modulation in freely moving rats performing a range of natural locomotor procedures. We found that the activation of hindlimb motor cortex preceded gait initiation. During overground locomotion, the motor cortex exhibited consistent neuronal population responses that were synchronized with the spatiotemporal activation of hindlimb motoneurons. Behaviors requiring enhanced muscle activity or skilled paw placement correlated with substantial adjustment in neuronal population responses. In contrast, all rats exhibited a reduction of cortical activity during more automated behavior, such as stepping on a treadmill. Despite the facultative role of the motor cortex in the production of locomotion in rats, these results show that the encoding of hindlimb features in motor cortex dynamics is comparable in rats and cats. However, the extent of motor cortex modulations appears linked to the degree of volitional engagement and complexity of the task, reemphasizing the importance of goal-directed behaviors for motor control studies, rehabilitation, and neuroprosthetics. We mapped the neuronal population responses in the hindlimb motor cortex to hindlimb kinematics and hindlimb muscle synergies across a spectrum of natural locomotion behaviors. Robust task-specific neuronal population responses revealed that the rat motor cortex displays similar modulation as other mammals during locomotion. However, the reduced motor cortex activity during more automated behaviors suggests a relationship between the degree of engagement and task complexity. This relationship

Structural brain correlates of sensorimotor gating in antipsychotic-naive men with first-episode schizophrenia

DEFF Research Database (Denmark)

Hammer, Trine B; Oranje, Bob; Skimminge, Arnold

2013-01-01

in the left rostral dorsal premotor cortex, the right presupplementary motor area and the anterior medial superior frontal gyrus bilaterally. Follow-up analyses suggested that the rostral dorsal premotor cortex and presupplementary motor area correlations were driven predominantly by the controls. Limitations......Background: Prepulse inhibition (PPI) of the startle reflex is modulated by a complex neural network. Prepulse inhibition impairments are found at all stages of schizophrenia. Previous magnetic resonance imaging (MRI) studies suggest that brain correlates of PPI differ between patients...... with schizophrenia and healthy controls; however, these studies included only patients with chronic illness and medicated patients. Our aim was to examine the structural brain correlates of PPI in antipsychotic-naive patients with first-episode schizophrenia. Methods: We performed acoustic PPI assessment...

Feature diagnosticity and task context shape activity in human scene-selective cortex.

Science.gov (United States)

Lowe, Matthew X; Gallivan, Jason P; Ferber, Susanne; Cant, Jonathan S

2016-01-15

Scenes are constructed from multiple visual features, yet previous research investigating scene processing has often focused on the contributions of single features in isolation. In the real world, features rarely exist independently of one another and likely converge to inform scene identity in unique ways. Here, we utilize fMRI and pattern classification techniques to examine the interactions between task context (i.e., attend to diagnostic global scene features; texture or layout) and high-level scene attributes (content and spatial boundary) to test the novel hypothesis that scene-selective cortex represents multiple visual features, the importance of which varies according to their diagnostic relevance across scene categories and task demands. Our results show for the first time that scene representations are driven by interactions between multiple visual features and high-level scene attributes. Specifically, univariate analysis of scene-selective cortex revealed that task context and feature diagnosticity shape activity differentially across scene categories. Examination using multivariate decoding methods revealed results consistent with univariate findings, but also evidence for an interaction between high-level scene attributes and diagnostic visual features within scene categories. Critically, these findings suggest visual feature representations are not distributed uniformly across scene categories but are shaped by task context and feature diagnosticity. Thus, we propose that scene-selective cortex constructs a flexible representation of the environment by integrating multiple diagnostically relevant visual features, the nature of which varies according to the particular scene being perceived and the goals of the observer. Copyright © 2015 Elsevier Inc. All rights reserved.

Role of Basal Ganglia in Swallowing Process: A Systematic Review

OpenAIRE

Hamideh Ghaemi; Davood Sobhani-Rad; Ali Arabi; Sadegh Saifpanahi; Zahra Ghayoumi Anaraki

2016-01-01

Objectives: The basal ganglia (BG) controls different patterns of behavior by receiving inputs from sensory-motor and pre-motor cortex and projecting it to pre-frontal, pre-motor and supplementary motor areas. As the exact role of BG in swallowing process has not been fully determined, we aimed at reviewing the published data on neurological control in the swallowing technique to have a better understanding of BG’s role in this performance.  Methods: English-language articles, w...

Role of the ventrolateral orbital cortex and medial prefrontal cortex in incentive downshift situations.

Science.gov (United States)

Ortega, Leonardo A; Glueck, Amanda C; Uhelski, Megan; Fuchs, Perry N; Papini, Mauricio R

2013-05-01

The present research evaluated the role of two prefrontal cortex areas, the ventrolateral orbital cortex (VLO) and the medial prefrontal cortex (mPFC), on two situations involving incentive downshifts, consummatory successive negative contrast (cSNC) with sucrose solutions and Pavlovian autoshaping following continuous vs. partial reinforcement with food pellets. Animals received electrolytic lesions and then were tested on cSNC, autoshaping, open-field activity, and sucrose sensitivity. Lesions of the VLO reduced suppression of consummatory behavior after the incentive downshift, but only during the first downshift trial, and also eliminated the enhancement of anticipatory behavior during partial reinforcement, relative to continuous reinforcement, in autoshaping. There was no evidence of specific effects of mPFC lesions on incentive downshifts. Open-field activity was also reduced by VLO lesions, but only in the central area, whereas mPFC lesions had no observable effects on activity. Animals with mPFC lesions exhibited decreased consumption of the lowest sucrose concentration, whereas no effects were observed in animals with VLO lesions. These results suggest that the VLO may exert nonassociative (i.e., motivational, emotional) influences on behavior in situations involving incentive downshifts. No clear role on incentive downshift was revealed by mPFC lesions. Copyright © 2013 Elsevier B.V. All rights reserved.

Visual Stimuli Induce Waves of Electrical Activity in Turtle Cortex

Science.gov (United States)

Prechtl, J. C.; Cohen, L. B.; Pesaran, B.; Mitra, P. P.; Kleinfeld, D.

1997-07-01

The computations involved in the processing of a visual scene invariably involve the interactions among neurons throughout all of visual cortex. One hypothesis is that the timing of neuronal activity, as well as the amplitude of activity, provides a means to encode features of objects. The experimental data from studies on cat [Gray, C. M., Konig, P., Engel, A. K. & Singer, W. (1989) Nature (London) 338, 334-337] support a view in which only synchronous (no phase lags) activity carries information about the visual scene. In contrast, theoretical studies suggest, on the one hand, the utility of multiple phases within a population of neurons as a means to encode independent visual features and, on the other hand, the likely existence of timing differences solely on the basis of network dynamics. Here we use widefield imaging in conjunction with voltage-sensitive dyes to record electrical activity from the virtually intact, unanesthetized turtle brain. Our data consist of single-trial measurements. We analyze our data in the frequency domain to isolate coherent events that lie in different frequency bands. Low frequency oscillations (scale differences in neuronal timing are present and persistent during visual processing.

Registration and Analysis of Bioelectric Activity of Sensory-Motor Cortex During the Electrical Stimulation of Nucleus Caudate in Rats

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Snežana Medenica-Milanović

2007-05-01

Full Text Available Background and purposeThe caudate circuit takes part in cognitive control of motor activity The purpose of the present work was registration and analysis of basic bioelectrical activity of ventral and dorsal sensory-motor cortex and nucleus caudate, study of the changes in EEG after nucleus caudate electrical stimulation and to identify of threshold level of electrical stimuli responsible for changes of electrical activity in registered brain area.Materials and methodsWe used 28 albino Wistar rat of both genders. After the animal fixation on stereotaxic apparatus to dry bone, the places for electrode fixation were marked. Two days after the electrodes had been implanted an EEG was registered so that the animals would adjust to the conditions and so they would repair the tissue reactions. EEG was registered with bipolar electrodes with ten-channeled apparatus. For first half an hour spontaneous activity of the brain was registered, and after that the head of nucleus caudate was stimulated with altered impulses of various voltages, frequency and duration.Results and conclusionsThreshold values of electric stimulus intensity from 3 to 5 V, frequency from 3 to 5 Hz, duration from 3 to 5 ms, by stimulation the head of nucleus caudate of rat, lead to the change of basal bioelectric activity of cerebrum. The change of bioelectric activity is firstly recorded in equilateral cortex, and with the higher intensity of the stimulus the changes overtake the contra lateral cortex.

High baseline activity in inferior temporal cortex improves neural and behavioral discriminability during visual categorization

Science.gov (United States)

Emadi, Nazli; Rajimehr, Reza; Esteky, Hossein

2014-01-01

Spontaneous firing is a ubiquitous property of neural activity in the brain. Recent literature suggests that this baseline activity plays a key role in perception. However, it is not known how the baseline activity contributes to neural coding and behavior. Here, by recording from the single neurons in the inferior temporal cortex of monkeys performing a visual categorization task, we thoroughly explored the relationship between baseline activity, the evoked response, and behavior. Specifically we found that a low-frequency (baseline activity. This enhancement of the baseline activity was then followed by an increase in the neural selectivity and the response reliability and eventually a higher behavioral performance. PMID:25404900

Activation of Phosphatidylinositol-Linked Dopamine Receptors Induces a Facilitation of Glutamate-Mediated Synaptic Transmission in the Lateral Entorhinal Cortex.

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Iulia Glovaci

Full Text Available The lateral entorhinal cortex receives strong inputs from midbrain dopamine neurons that can modulate its sensory and mnemonic function. We have previously demonstrated that 1 µM dopamine facilitates synaptic transmission in layer II entorhinal cortex cells via activation of D1-like receptors, increased cAMP-PKA activity, and a resulting enhancement of AMPA-receptor mediated currents. The present study assessed the contribution of phosphatidylinositol (PI-linked D1 receptors to the dopaminergic facilitation of transmission in layer II of the rat entorhinal cortex, and the involvement of phospholipase C activity and release of calcium from internal stores. Whole-cell patch-clamp recordings of glutamate-mediated evoked excitatory postsynaptic currents were obtained from pyramidal and fan cells. Activation of D1-like receptors using SKF38393, SKF83959, or 1 µM dopamine induced a reversible facilitation of EPSCs which was abolished by loading cells with either the phospholipase C inhibitor U-73122 or the Ca2+ chelator BAPTA. Neither the L-type voltage-gated Ca2+ channel blocker nifedipine, nor the L/N-type channel blocker cilnidipine, blocked the facilitation of synaptic currents. However, the facilitation was blocked by blocking Ca2+ release from internal stores via inositol 1,4,5-trisphosphate (InsP3 receptors or ryanodine receptors. Follow-up studies demonstrated that inhibiting CaMKII activity with KN-93 failed to block the facilitation, but that application of the protein kinase C inhibitor PKC(19-36 completely blocked the dopamine-induced facilitation. Overall, in addition to our previous report indicating a role for the cAMP-PKA pathway in dopamine-induced facilitation of synaptic transmission, we demonstrate here that the dopaminergic facilitation of synaptic responses in layer II entorhinal neurons also relies on a signaling cascade dependent on PI-linked D1 receptors, PLC, release of Ca2+ from internal stores, and PKC activation which is

Activity-dependent regulation of MHC class I expression in the developing primary visual cortex of the common marmoset monkey

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Schlumbohm Christina

2011-01-01

Full Text Available Abstract Background Several recent studies have highlighted the important role of immunity-related molecules in synaptic plasticity processes in the developing and adult mammalian brains. It has been suggested that neuronal MHCI (major histocompatibility complex class I genes play a role in the refinement and pruning of synapses in the developing visual system. As a fast evolutionary rate may generate distinct properties of molecules in different mammalian species, we studied the expression of MHCI molecules in a nonhuman primate, the common marmoset monkey (Callithrix jacchus. Methods and results Analysis of expression levels of MHCI molecules in the developing visual cortex of the common marmoset monkeys revealed a distinct spatio-temporal pattern. High levels of expression were detected very early in postnatal development, at a stage when synaptogenesis takes place and ocular dominance columns are formed. To determine whether the expression of MHCI molecules is regulated by retinal activity, animals were subjected to monocular enucleation. Levels of MHCI heavy chain subunit transcripts in the visual cortex were found to be elevated in response to monocular enucleation. Furthermore, MHCI heavy chain immunoreactivity revealed a banded pattern in layer IV of the visual cortex in enucleated animals, which was not observed in control animals. This pattern of immunoreactivity indicated that higher expression levels were associated with retinal activity coming from the intact eye. Conclusions These data demonstrate that, in the nonhuman primate brain, expression of MHCI molecules is regulated by neuronal activity. Moreover, this study extends previous findings by suggesting a role for neuronal MHCI molecules during synaptogenesis in the visual cortex.

Dissociation of object and spatial visual processing pathways in human extrastriate cortex

Energy Technology Data Exchange (ETDEWEB)

Haxby, J.V.; Grady, C.L.; Horwitz, B.; Ungerleider, L.G.; Mishkin, M.; Carson, R.E.; Herscovitch, P.; Schapiro, M.B.; Rapoport, S.I. (National Institutes of Health, Bethesda, MD (USA))

1991-03-01

The existence and neuroanatomical locations of separate extrastriate visual pathways for object recognition and spatial localization were investigated in healthy young men. Regional cerebral blood flow was measured by positron emission tomography and bolus injections of H2(15)O, while subjects performed face matching, dot-location matching, or sensorimotor control tasks. Both visual matching tasks activated lateral occipital cortex. Face discrimination alone activated a region of occipitotemporal cortex that was anterior and inferior to the occipital area activated by both tasks. The spatial location task alone activated a region of lateral superior parietal cortex. Perisylvian and anterior temporal cortices were not activated by either task. These results demonstrate the existence of three functionally dissociable regions of human visual extrastriate cortex. The ventral and dorsal locations of the regions specialized for object recognition and spatial localization, respectively, suggest some homology between human and nonhuman primate extrastriate cortex, with displacement in human brain, possibly related to the evolution of phylogenetically newer cortical areas.

Functional MR imaging and traumatic paraplegia: preliminary report.

Science.gov (United States)

Sabbah, P; Lévêque, C; Pfefer, F; Nioche, C; Gay, S; Sarrazin, J L; Barouti, H; Tadie, M; Cordoliani, Y S

2000-12-01

To evaluate residual activity in the sensorimotor cortex of the lower limbs in paraplegia. 5 patients suffering from a complete paralysis after traumatic medullar lesion (ASIA=A). Clinical evaluation of motility and sensitivity. 1. Control functional MR study of the sensorimotor cortex during simultaneous movements of hands, imaginary motor task and passive hands stimulation. 2. Concerning the lower limbs, 3 fMRI conditions: 1-patient attempts to move his toes with flexion-extension, 2-mental imagery task of the same movement, 3-peripheral passive proprio-somesthesic stimulation (squeezing) of the big toes. Activations were observed in the primary sensorimotor cortex (M1), premotor regions and in the supplementary motor area (SMA) during movement and mental imaginary tasks in the control study and during attempt to move and mental imaginary tasks in the study concerning the lower limbs. Passive somesthesic stimulation generated activation posterior to the central sulcus for 2 patients. Activations in the sensorimotor cortex of the lower limbs can be generated either by attempting to move or mental evocation. In spite of a clinical evaluation of complete paraplegia, fMRI can show a persistence of sensitive anatomic conduction, confirmed by Somesthesic Evoked Potentials.

Motor areas of the frontal cortex in patients with motor eloquent brain lesions.

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Bulubas, Lucia; Sabih, Jamil; Wohlschlaeger, Afra; Sollmann, Nico; Hauck, Theresa; Ille, Sebastian; Ringel, Florian; Meyer, Bernhard; Krieg, Sandro M

2016-12-01

OBJECTIVE Because of its huge clinical potential, the importance of premotor areas for motor function itself and plastic reshaping due to tumors or ischemic brain lesions has received increased attention. Thus, in this study the authors used navigated transcranial magnetic stimulation (nTMS) to investigate whether tumorous brain lesions induce a change in motor cortex localization in the human brain. METHODS Between 2010 and 2013, nTMS motor mapping was performed in a prospective cohort of 100 patients with brain tumors in or adjacent to the rolandic cortex. Spatial data analysis was performed by normalization of the individual motor maps and creation of overlays according to tumor location. Analysis of motor evoked potential (MEP) latencies was performed regarding mean overall latencies and potentially polysynaptic latencies, defined as latencies longer than 1 SD above the mean value. Hemispheric dominance, lesion location, and motor-function deficits were also considered. RESULTS Graphical analysis showed that motor areas were not restricted to the precentral gyrus. Instead, they spread widely in the anterior-posterior direction. An analysis of MEP latency showed that mean MEP latencies were shortest in the precentral gyrus and longest in the superior and middle frontal gyri. The percentage of latencies longer than 1 SD differed widely across gyri. The dominant hemisphere showed a greater number of longer latencies than the nondominant hemisphere (p < 0.0001). Moreover, tumor location-dependent changes in distribution of polysynaptic latencies were observed (p = 0.0002). Motor-function deficit did not show any statistically significant effect. CONCLUSIONS The distribution of primary and polysynaptic motor areas changes in patients with brain tumors and highly depends on tumor location. Thus, these data should be considered for resection planning.

Influence of the language dominant hemisphere on the activation region of the cerebral cortex during mastication

International Nuclear Information System (INIS)

Matsushima, Yasuhiko

2005-01-01

We used functional magnetic resonance imaging (fMRI) to examine the relationship of the activation region of the cerebral cortex during mastication with the language dominant hemisphere. Twelve healthy subjects were asked to chew a special gum 50 times on each side of the mouth, the gum changed color, becoming a deeper red, as it was chewed. The depth of red of the chewed gum was used to ascertain the habitual masticatory side. Measurements were also performed on a conventional whole body 1.5 T clinical scanner using a single shot, multislice echo-planar imaging sequence. The subjects were asked to masticate first on the right side, and then on the left side. As well, they were instructed to do a shiritori test, which is a word game. Computer analysis of the fMRI was done using statistical parametric mapping (SPM) 99 software (p<0.001, paired t-test). We found that the sensorimotor cortex activated by masticatory movements always contains language dominant hemisphere. (author)

Comparison of laterality index of upper and lower limb movement using brain activated fMRI

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Harirchian, Mohammad Hossein; Oghabian, Mohammad Ali; Rezvanizadeh, Alireza; Bolandzadeh, Niousha

2008-03-01

Asymmetry of bilateral cerebral function, i.e. laterality, is an important phenomenon in many brain actions such as motor functions. This asymmetry maybe altered in some clinical conditions such as Multiple Sclerosis (MS). The aim of this study was to delineate the laterality differences for upper and lower limbs in healthy subjects to compare this pattern with subjects suffering from MS in advance. Hence 9 Male healthy subjects underwent fMRI assessment, while they were asked to move their limbs in a predetermined pattern. The results showed that hands movement activates the brain with a significant lateralization in pre-motor cortex in comparison with lower limb. Also, dominant hands activate brain more lateralized than the non-dominant hand. In addition, Left basal ganglia were observed to be activated regardless of the hand used, While, These patterns of Brain activation was not detected in lower limbs. We hypothesize that this difference might be attributed to this point that hand is usually responsible for precise and fine voluntary movements, whereas lower limb joints are mainly responsible for locomotion, a function integrating voluntary and automatic bilateral movements.

Effect of axillary blockade on regional cerebral blood flow during static handgrip

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Friedman, D B; Friberg, L; Mitchell, J H

1991-01-01

Regional cerebral blood flow (rCBF) was determined at rest and during static handgrip before and after regional blockade with lidocaine. A fast rotating single photon emission computer tomograph system with 133Xe inhalation was used at orbitomeatal plane (OM) +2.5 and +6.5 cm in eight subjects. M...... static handgrip, there was no increase in rCBF after partial sensory and motor blockade. Thus bilateral activation occurs in the premotor and motor sensory cortex during static handgrip, and this activation requires neural feedback from the contracting muscles....

Reciprocal activation/inactivation of ERK in the amygdala and frontal cortex is correlated with the degree of novelty of an open-field environment.

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Sanguedo, Frederico Velasco; Dias, Caio Vitor Bueno; Dias, Flavia Regina Cruz; Samuels, Richard Ian; Carey, Robert J; Carrera, Marinete Pinheiro

2016-03-01

Phosphorylated extracellular signal-regulated kinase (ERK) has been used to identify brain areas activated by exogenous stimuli including psychostimulant drugs. Assess the role of the amygdala in emotional responses. Experimental manipulations were performed in which environmental familiarity was the variable. To provide the maximal degree of familiarity, ERK was measured after removal from the home cage and re-placement back into the same cage. To maximize exposure to an unfamiliar environment, ERK was measured following placement into a novel open field. To assess whether familiarity was the critical variable in the ERK response to the novel open field, ERK was also measured after either four or eight placements into the same environment. ERK quantification was carried out in the amygdala, frontal cortex, and the nucleus accumbens. After home cage re-placement, ERK activation was found in the frontal cortex and nucleus accumbens but was absent in the amygdala. Following placement in a novel environment, ERK activation was more prominent in the amygdala than the frontal cortex or nucleus accumbens. In contrast, with habituation to the novel environment, ERK phosphors declined markedly in the amygdala but increased in the frontal cortex and nucleus accumbens to the level observed following home cage re-placement. The differential responsiveness of the amygdala versus the frontal cortex and the nucleus accumbens to a novel versus a habituated environment is consistent with a reciprocal interaction between these neural systems and points to their important role in the mediation of behavioral activation to novelty and behavioral inactivation with habituation.

Altered neuronal activities in the motor cortex with impaired motor performance in adult rats observed after infusion of cerebrospinal fluid from amyotrophic lateral sclerosis patients.

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Sankaranarayani, R; Nalini, A; Rao Laxmi, T; Raju, T R

2010-01-05

Although definite evidences are available to state that, neuronal activity is a prime determinant of animal behavior, the specific relationship between local field potentials of the motor cortex after intervention with CSF from human patients and animal behavior have remained opaque. The present study has investigated whether cerebrospinal fluid from sporadic amyotrophic lateral sclerosis (sALS) patients could disrupt neuronal activity of the motor cortex, which could be associated with disturbances in the motor performance of adult rats. CSF from ALS patients (ALS-CSF) was infused into the lateral ventricle of Wistar rats. After 24h, the impact of ALS-CSF on the local field potentials (LFPs) of the motor cortex and on the motor behavior of animals were examined. The results indicate that ALS-CSF produced a bivariate distribution on the relative power values of the LFPs of the motor cortex 24h following infusion. However, the behavioral results did not show bimodality, instead showed consistent decrease in motor performance: on rotarod and grip strength meter. The neuronal activity of the motor cortex negatively correlated with the duration of ALS symptoms at the time of lumbar puncture. Although the effect of ALS-CSF was more pronounced at 24h following infusion, the changes observed in LFPs and motor performance appeared to revert to baseline values at later time points of testing. In the current study, we have shown that, ALS-CSF has the potential to perturb neuronal activity of the rat motor cortex which was associated with poor performance on motor function tests.

Effects of Arousal on Mouse Sensory Cortex Depend on Modality

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Daisuke Shimaoka

2018-03-01

Full Text Available Summary: Changes in arousal modulate the activity of mouse sensory cortex, but studies in different mice and different sensory areas disagree on whether this modulation enhances or suppresses activity. We measured this modulation simultaneously in multiple cortical areas by imaging mice expressing voltage-sensitive fluorescent proteins (VSFP. VSFP imaging estimates local membrane potential across large portions of cortex. We used temporal filters to predict local potential from running speed or from pupil dilation, two measures of arousal. The filters provided good fits and revealed that the effects of arousal depend on modality. In the primary visual cortex (V1 and auditory cortex (Au, arousal caused depolarization followed by hyperpolarization. In the barrel cortex (S1b and a secondary visual area (LM, it caused only hyperpolarization. In all areas, nonetheless, arousal reduced the phasic responses to trains of sensory stimuli. These results demonstrate diverse effects of arousal across sensory cortex but similar effects on sensory responses. : Shimaoka et al. use voltage-sensitive imaging to show that the effects of arousal on the mouse cortex are markedly different across areas and over time. In all the sensory areas studied, nonetheless, arousal reduced the phasic voltage responses to trains of sensory stimuli. Keywords: cerebral cortex, cortical state, locomotion, sensory processing, widefield imaging

Gallic Acid Is the Major Active Component of Cortex Moutan in Inhibiting Immune Maturation of Human Monocyte-Derived Dendritic Cells

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Ben Chung Lap Chan

2015-09-01

Full Text Available Atopic dermatitis (AD is a widely prevalent and chronically relapsing inflammatory skin disease. Penta Herbs Formula (PHF is efficacious in improving the quality of life and reducing topical corticosteroid used in children with AD and one of the active herbs it contains is Cortex Moutan. Recent studies showed that altered functions of dendritic cells (DC were observed in atopic individuals, suggesting that DC might play a major role in the generation and maintenance of inflammation by their production of pro-inflammatory cytokines. Hence, the aims of the present study were to identify the major active component(s of Cortex Moutan, which might inhibit DC functions and to investigate their possible interactions with conventional corticosteroid on inhibiting the development of DC from monocytes. Monocyte-derived dendritic cells (moDC culture model coupled with the high-speed counter-current chromatography (HSCCC, high pressure liquid chromatography (HPLC and Liquid Chromatography-Mass Spectrometry (LCMS analyses were used. Gallic acid was the major active component from Cortex Moutan which could dose dependently inhibit interleukin (IL-12 p40 and the functional cluster of differentiation (CD surface markers CD40, CD80, CD83 and CD86 expression from cytokine cocktail-activated moDC. Gallic acid could also lower the concentration of hydrocortisone required to inhibit the activation of DC.

From prosodic structure to acoustic saliency: A fMRI investigation of speech rate, clarity, and emphasis

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Golfinopoulos, Elisa

Acoustic variability in fluent speech can arise at many stages in speech production planning and execution. For example, at the phonological encoding stage, the grouping of phonemes into syllables determines which segments are coarticulated and, by consequence, segment-level acoustic variation. Likewise phonetic encoding, which determines the spatiotemporal extent of articulatory gestures, will affect the acoustic detail of segments. Functional magnetic resonance imaging (fMRI) was used to measure brain activity of fluent adult speakers in four speaking conditions: fast, normal, clear, and emphatic (or stressed) speech. These speech manner changes typically result in acoustic variations that do not change the lexical or semantic identity of productions but do affect the acoustic saliency of phonemes, syllables and/or words. Acoustic responses recorded inside the scanner were assessed quantitatively using eight acoustic measures and sentence duration was used as a covariate of non-interest in the neuroimaging analysis. Compared to normal speech, emphatic speech was characterized acoustically by a greater difference between stressed and unstressed vowels in intensity, duration, and fundamental frequency, and neurally by increased activity in right middle premotor cortex and supplementary motor area, and bilateral primary sensorimotor cortex. These findings are consistent with right-lateralized motor planning of prosodic variation in emphatic speech. Clear speech involved an increase in average vowel and sentence durations and average vowel spacing, along with increased activity in left middle premotor cortex and bilateral primary sensorimotor cortex. These findings are consistent with an increased reliance on feedforward control, resulting in hyper-articulation, under clear as compared to normal speech. Fast speech was characterized acoustically by reduced sentence duration and average vowel spacing, and neurally by increased activity in left anterior frontal

Early (M170) activation of face-specific cortex by face-like objects.

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Hadjikhani, Nouchine; Kveraga, Kestutis; Naik, Paulami; Ahlfors, Seppo P

2009-03-04

The tendency to perceive faces in random patterns exhibiting configural properties of faces is an example of pareidolia. Perception of 'real' faces has been associated with a cortical response signal arising at approximately 170 ms after stimulus onset, but what happens when nonface objects are perceived as faces? Using magnetoencephalography, we found that objects incidentally perceived as faces evoked an early (165 ms) activation in the ventral fusiform cortex, at a time and location similar to that evoked by faces, whereas common objects did not evoke such activation. An earlier peak at 130 ms was also seen for images of real faces only. Our findings suggest that face perception evoked by face-like objects is a relatively early process, and not a late reinterpretation cognitive phenomenon.

Insulin-Independent GABAA Receptor-Mediated Response in the Barrel Cortex of Mice with Impaired Met Activity.

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Lo, Fu-Sun; Erzurumlu, Reha S; Powell, Elizabeth M

2016-03-30

Autism spectrum disorder (ASD) is a neurodevelopmental disorder caused by genetic variants, susceptibility alleles, and environmental perturbations. The autism associated geneMETtyrosine kinase has been implicated in many behavioral domains and endophenotypes of autism, including abnormal neural signaling in human sensory cortex. We investigated somatosensory thalamocortical synaptic communication in mice deficient in Met activity in cortical excitatory neurons to gain insights into aberrant somatosensation characteristic of ASD. The ratio of excitation to inhibition is dramatically increased due to decreased postsynaptic GABAAreceptor-mediated inhibition in the trigeminal thalamocortical pathway of mice lacking active Met in the cerebral cortex. Furthermore, in contrast to wild-type mice, insulin failed to increase GABAAreceptor-mediated response in the barrel cortex of mice with compromised Met signaling. Thus, lacking insulin effects may be a risk factor in ASD pathogenesis. A proposed common cause of neurodevelopmental disorders is an imbalance in excitatory neural transmission, provided by the glutamatergic neurons, and the inhibitory signals from the GABAergic interneurons. Many genes associated with autism spectrum disorders impair synaptic transmission in the expected cell type. Previously, inactivation of the autism-associated Met tyrosine kinase receptor in GABAergic interneurons led to decreased inhibition. In thus report, decreased Met signaling in glutamatergic neurons had no effect on excitation, but decimated inhibition. Further experiments indicate that loss of Met activity downregulates GABAAreceptors on glutamatergic neurons in an insulin independent manner. These data provide a new mechanism for the loss of inhibition and subsequent abnormal excitation/inhibition balance and potential molecular candidates for treatment or prevention. Copyright © 2016 the authors 0270-6474/16/363691-07$15.00/0.

Effects of chewing in working memory processing.

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Hirano, Yoshiyuki; Obata, Takayuki; Kashikura, Kenichi; Nonaka, Hiroi; Tachibana, Atsumichi; Ikehira, Hiroo; Onozuka, Minoru

2008-05-09

It has been generally suggested that chewing produces an enhancing effect on cognitive performance-related aspects of memory by the test battery. Furthermore, recent studies have shown that chewing is associated with activation of various brain regions, including the prefrontal cortex. However, little is known about the relation between cognitive performances affected by chewing and the neuronal activity in specified regions in the brain. We therefore examined the effects of chewing on neuronal activities in the brain during a working memory task using fMRI. The subjects chewed gum, without odor and taste components, between continuously performed two- or three-back (n-back) working memory tasks. Chewing increased the BOLD signals in the middle frontal gyrus (Brodmann's areas 9 and 46) in the dorsolateral prefrontal cortex during the n-back tasks. Furthermore, there were more prominent activations in the right premotor cortex, precuneus, thalamus, hippocampus and inferior parietal lobe during the n-back tasks after the chewing trial. These results suggest that chewing may accelerate or recover the process of working memory besides inducing improvement in the arousal level by the chewing motion.

Implied motion because of instability in Hokusai Manga activates the human motion-sensitive extrastriate visual cortex: an fMRI study of the impact of visual art.

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Osaka, Naoyuki; Matsuyoshi, Daisuke; Ikeda, Takashi; Osaka, Mariko

2010-03-10

The recent development of cognitive neuroscience has invited inference about the neurosensory events underlying the experience of visual arts involving implied motion. We report functional magnetic resonance imaging study demonstrating activation of the human extrastriate motion-sensitive cortex by static images showing implied motion because of instability. We used static line-drawing cartoons of humans by Hokusai Katsushika (called 'Hokusai Manga'), an outstanding Japanese cartoonist as well as famous Ukiyoe artist. We found 'Hokusai Manga' with implied motion by depicting human bodies that are engaged in challenging tonic posture significantly activated the motion-sensitive visual cortex including MT+ in the human extrastriate cortex, while an illustration that does not imply motion, for either humans or objects, did not activate these areas under the same tasks. We conclude that motion-sensitive extrastriate cortex would be a critical region for perception of implied motion in instability.

Metaphorical motion in mathematical reasoning: further evidence for pre-motor implementation of structure mapping in abstract domains.

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Fields, Chris

2013-08-01

The theory of computation and category theory both employ arrow-based notations that suggest that the basic metaphor "state changes are like motions" plays a fundamental role in all mathematical reasoning involving formal manipulations. If this is correct, structure-mapping inferences implemented by the pre-motor action planning system can be expected to be involved in solving any mathematics problems not solvable by table lookups and number line manipulations alone. Available functional imaging studies of multi-digit arithmetic, algebra, geometry and calculus problem solving are consistent with this expectation.

Functional sex differences in human primary auditory cortex

International Nuclear Information System (INIS)

Ruytjens, Liesbet; Georgiadis, Janniko R.; Holstege, Gert; Wit, Hero P.; Albers, Frans W.J.; Willemsen, Antoon T.M.

2007-01-01

We used PET to study cortical activation during auditory stimulation and found sex differences in the human primary auditory cortex (PAC). Regional cerebral blood flow (rCBF) was measured in 10 male and 10 female volunteers while listening to sounds (music or white noise) and during a baseline (no auditory stimulation). We found a sex difference in activation of the left and right PAC when comparing music to noise. The PAC was more activated by music than by noise in both men and women. But this difference between the two stimuli was significantly higher in men than in women. To investigate whether this difference could be attributed to either music or noise, we compared both stimuli with the baseline and revealed that noise gave a significantly higher activation in the female PAC than in the male PAC. Moreover, the male group showed a deactivation in the right prefrontal cortex when comparing noise to the baseline, which was not present in the female group. Interestingly, the auditory and prefrontal regions are anatomically and functionally linked and the prefrontal cortex is known to be engaged in auditory tasks that involve sustained or selective auditory attention. Thus we hypothesize that differences in attention result in a different deactivation of the right prefrontal cortex, which in turn modulates the activation of the PAC and thus explains the sex differences found in the activation of the PAC. Our results suggest that sex is an important factor in auditory brain studies. (orig.)

Functional sex differences in human primary auditory cortex

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Ruytjens, Liesbet [University Medical Center Groningen, Department of Otorhinolaryngology, Groningen (Netherlands); University Medical Center Utrecht, Department Otorhinolaryngology, P.O. Box 85500, Utrecht (Netherlands); Georgiadis, Janniko R. [University of Groningen, University Medical Center Groningen, Department of Anatomy and Embryology, Groningen (Netherlands); Holstege, Gert [University of Groningen, University Medical Center Groningen, Center for Uroneurology, Groningen (Netherlands); Wit, Hero P. [University Medical Center Groningen, Department of Otorhinolaryngology, Groningen (Netherlands); Albers, Frans W.J. [University Medical Center Utrecht, Department Otorhinolaryngology, P.O. Box 85500, Utrecht (Netherlands); Willemsen, Antoon T.M. [University Medical Center Groningen, Department of Nuclear Medicine and Molecular Imaging, Groningen (Netherlands)

2007-12-15

We used PET to study cortical activation during auditory stimulation and found sex differences in the human primary auditory cortex (PAC). Regional cerebral blood flow (rCBF) was measured in 10 male and 10 female volunteers while listening to sounds (music or white noise) and during a baseline (no auditory stimulation). We found a sex difference in activation of the left and right PAC when comparing music to noise. The PAC was more activated by music than by noise in both men and women. But this difference between the two stimuli was significantly higher in men than in women. To investigate whether this difference could be attributed to either music or noise, we compared both stimuli with the baseline and revealed that noise gave a significantly higher activation in the female PAC than in the male PAC. Moreover, the male group showed a deactivation in the right prefrontal cortex when comparing noise to the baseline, which was not present in the female group. Interestingly, the auditory and prefrontal regions are anatomically and functionally linked and the prefrontal cortex is known to be engaged in auditory tasks that involve sustained or selective auditory attention. Thus we hypothesize that differences in attention result in a different deactivation of the right prefrontal cortex, which in turn modulates the activation of the PAC and thus explains the sex differences found in the activation of the PAC. Our results suggest that sex is an important factor in auditory brain studies. (orig.)

Monoamine oxidase-A and B activities in the cerebellum and frontal cortex of children and young adults with autism.

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Gu, Feng; Chauhan, Ved; Chauhan, Abha

2017-10-01

Monoamine oxidases (MAOs) catalyze the metabolism of monoamine neurotransmitters, such as serotonin, dopamine, and norepinephrine, and are key regulators for brain function. In this study, we analyzed the activities of MAO-A and MAO-B in the cerebellum and frontal cortex from subjects with autism and age-matched control subjects. In the cerebellum, MAO-A activity in subjects with autism (aged 4-38 years) was significantly lower by 20.6% than in controls. When the subjects were divided into children (aged 4-12 years) and young adults (aged 13-38 years) subgroups, a significant decrease by 27.8% in the MAO-A activity was observed only in children with autism compared with controls. When the 95% confidence interval of the control group was taken as a reference range, reduced activity of MAO-A was observed in 70% of children with autism. In the frontal cortex, MAO-A activity in children with autism was also lower by 30% than in the control group, and impaired activity of MAO-A was observed in 55.6% of children with autism, although the difference between the autism and control groups was not significant when all subjects were considered. On the contrary, there was no significant difference in MAO-B activity in both the cerebellum and frontal cortex between children with autism and the control group as well as in adults. These results suggest impaired MAO-A activity in the brain of subjects with autism, especially in children with autism. Decreased activity of MAOs may lead to increased levels of monoaminergic neurotransmitters, such as serotonin, which have been suggested to have a critical role in autism. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Effects of exercise on brain activity during walking in older adults: a randomized controlled trial.

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Shimada, Hiroyuki; Ishii, Kenji; Makizako, Hyuma; Ishiwata, Kiichi; Oda, Keiichi; Suzukawa, Megumi

2017-05-30

Physical activity may preserve neuronal plasticity, increase synapse formation, and cause the release of hormonal factors that promote neurogenesis and neuronal function. Previous studies have reported enhanced neurocognitive function following exercise training. However, the specific cortical regions activated during exercise training remain largely undefined. In this study, we quantitatively and objectively evaluated the effects of exercise on brain activity during walking in healthy older adults. A total of 24 elderly women (75-83 years old) were randomly allocated to either an intervention group or a control group. Those in the intervention group attended 3 months of biweekly 90-min sessions focused on aerobic exercise, strength training, and physical therapy. We monitored changes in regional cerebral glucose metabolism during walking in both groups using positron emission tomography (PET) and [ 18 F]fluorodeoxyglucose (FDG). All subjects completed the 3-month experiment and the adherence to the exercise program was 100%. Compared with the control group, the intervention group showed a significantly greater step length in the right foot after 3 months of physical activity. The FDG-PET assessment revealed a significant post-intervention increase in regional glucose metabolism in the left posterior entorhinal cortex, left superior temporal gyrus, and right superior temporopolar area in the intervention group. Interestingly, the control group showed a relative increase in regional glucose metabolism in the left premotor and supplemental motor areas, left and right somatosensory association cortex, and right primary visual cortex after the 3-month period. We found no significant differences in FDG uptake between the intervention and control groups before vs. after the intervention. Exercise training increased activity in specific brain regions, such as the precuneus and entorhinal cortices, which play an important role in episodic and spatial memory. Further

Functional brain mapping using H{sub 2}{sup 15}O positron emission tomography (II): mapping of human working memory

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Lee, Jae Sung; Lee, Dong Soo; Lee, Sang Kun; Nam, Hyun Woo; Kim, Seok Ki; Park, Kwang Suk; Jeong, Jae Min; Chung, June Key; Lee, Myung Chul [College of Medicine, Seoul National Univ., Seoul (Korea, Republic of)

1998-08-01

To localize and compare the neural basis of verbal and visual human working memory, we performed functional activation study using H{sub 2}{sup 15}O PET. Repeated H{sub 2}{sup 15}O PET scans with one control and three different activation tasks were performed on six right-handed normal volunteers. Each activation task was composed of 13 matching trials. On each trial, four targets, a fixation dot and a prove were presented sequentially and subject's tasks was to press a response button to indicate whether or not the prove was one of the previous targets. Short meaningful Korean words, simple drawings and monochromic pictures of human faces were used as matching objects for verbal or visual memory. All the images were spatially normalized and the differences between control and activation states were statistically analyzed using SPM96. Statistical analysis of verbal memory activation with short words showed activation in the left Broca's area, premotor cortex, cerebellum and right cingulate gyrus. In verbal memory with simple drawing, activation was shown in the larger regions including where activated with short words and left superior temporal cortex, basal ganglia, thalamus, prefrontal cortex, anterior portion of right superior temporal gyrus and right infero-lateral frontal cortex. On the other hand, the visual memory task activated predominantly right-sided structures, especially inferior frontal cortex, supplementary motor cortex and superior parietal cortex. The results are consistent with the hypothesis of the laterality and dissociation of the verbal and visual working memory from the invasive electrophysiological studies and emphasize the pivotal role of frontal cortex and cingulate gyrus in working memory system.

Visuomotor Dissociation in Cerebral Scaling of Size.

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Adriaan R E Potgieser

Full Text Available Estimating size and distance is crucial in effective visuomotor control. The concept of an internal coordinate system implies that visual and motor size parameters are scaled onto a common template. To dissociate perceptual and motor components in such scaling, we performed an fMRI experiment in which 16 right-handed subjects copied geometric figures while the result of drawing remained out of sight. Either the size of the example figure varied while maintaining a constant size of drawing (visual incongruity or the size of the examples remained constant while subjects were instructed to make changes in size (motor incongruity. These incongruent were compared to congruent conditions. Statistical Parametric Mapping (SPM8 revealed brain activations related to size incongruity in the dorsolateral prefrontal and inferior parietal cortex, pre-SMA / anterior cingulate and anterior insula, dominant in the right hemisphere. This pattern represented simultaneous use of a 'resized' virtual template and actual picture information requiring spatial working memory, early-stage attention shifting and inhibitory control. Activations were strongest in motor incongruity while right pre-dorsal premotor activation specifically occurred in this condition. Visual incongruity additionally relied on a ventral visual pathway. Left ventral premotor activation occurred in all variably sized drawing while constant visuomotor size, compared to congruent size variation, uniquely activated the lateral occipital cortex additional to superior parietal regions. These results highlight size as a fundamental parameter in both general hand movement and movement guided by objects perceived in the context of surrounding 3D space.

Mapping the after-effects of theta burst stimulation on the human auditory cortex with functional imaging.

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Andoh, Jamila; Zatorre, Robert J

2012-09-12

Auditory cortex pertains to the processing of sound, which is at the basis of speech or music-related processing. However, despite considerable recent progress, the functional properties and lateralization of the human auditory cortex are far from being fully understood. Transcranial Magnetic Stimulation (TMS) is a non-invasive technique that can transiently or lastingly modulate cortical excitability via the application of localized magnetic field pulses, and represents a unique method of exploring plasticity and connectivity. It has only recently begun to be applied to understand auditory cortical function. An important issue in using TMS is that the physiological consequences of the stimulation are difficult to establish. Although many TMS studies make the implicit assumption that the area targeted by the coil is the area affected, this need not be the case, particularly for complex cognitive functions which depend on interactions across many brain regions. One solution to this problem is to combine TMS with functional Magnetic resonance imaging (fMRI). The idea here is that fMRI will provide an index of changes in brain activity associated with TMS. Thus, fMRI would give an independent means of assessing which areas are affected by TMS and how they are modulated. In addition, fMRI allows the assessment of functional connectivity, which represents a measure of the temporal coupling between distant regions. It can thus be useful not only to measure the net activity modulation induced by TMS in given locations, but also the degree to which the network properties are affected by TMS, via any observed changes in functional connectivity. Different approaches exist to combine TMS and functional imaging according to the temporal order of the methods. Functional MRI can be applied before, during, after, or both before and after TMS. Recently, some studies interleaved TMS and fMRI in order to provide online mapping of the functional changes induced by TMS. However, this

Parietal operculum and motor cortex activities predict motor recovery in moderate to severe stroke

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Firdaus Fabrice Hannanu

2017-01-01

In subacute stroke, fMRI brain activity related to passive movement measured in a sensorimotor network defined by activity during voluntary movement predicted motor recovery better than baseline motor-FMS alone. Furthermore, fMRI sensorimotor network activity measures considered alone allowed excellent clinical recovery prediction and may provide reliable biomarkers for assessing new therapies in clinical trial contexts. Our findings suggest that neural reorganization related to motor recovery from moderate to severe stroke results from balanced changes in ipsilesional MI (BA4a and a set of phylogenetically more archaic sensorimotor regions in the ventral sensorimotor trend, in which OP1 and OP4 processes may complement the ipsilesional dorsal motor cortex in achieving compensatory sensorimotor recovery.

The temporal structure of resting-state brain activity in the medial prefrontal cortex predicts self-consciousness.

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Huang, Zirui; Obara, Natsuho; Davis, Henry Hap; Pokorny, Johanna; Northoff, Georg

2016-02-01

Recent studies have demonstrated an overlap between the neural substrate of resting-state activity and self-related processing in the cortical midline structures (CMS). However, the neural and psychological mechanisms mediating this so-called "rest-self overlap" remain unclear. To investigate the neural mechanisms, we estimated the temporal structure of spontaneous/resting-state activity, e.g. its long-range temporal correlations or self-affinity across time as indexed by the power-law exponent (PLE). The PLE was obtained in resting-state activity in the medial prefrontal cortex (MPFC) and the posterior cingulate cortex (PCC) in 47 healthy subjects by functional magnetic resonance imaging (fMRI). We performed correlation analyses of the PLE and Revised Self-Consciousness Scale (SCSR) scores, which enabled us to access different dimensions of self-consciousness and specified rest-self overlap in a psychological regard. The PLE in the MPFC's resting-state activity correlated with private self-consciousness scores from the SCSR. Conversely, we found no correlation between the PLE and the other subscales of the SCSR (public, social) or between other resting-state measures, including functional connectivity, and the SCSR subscales. This is the first evidence for the association between the scale-free dynamics of resting-state activity in the CMS and the private dimension of self-consciousness. This finding implies the relationship of especially the private dimension of self with the temporal structure of resting-state activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Activation of prefrontal cortex and anterior thalamus in alcoholic subjects on exposure to alcohol-specific cues.

Science.gov (United States)

George, M S; Anton, R F; Bloomer, C; Teneback, C; Drobes, D J; Lorberbaum, J P; Nahas, Z; Vincent, D J

2001-04-01

Functional imaging studies have recently demonstrated that specific brain regions become active in cocaine addicts when they are exposed to cocaine stimuli. To test whether there are regional brain activity differences during alcohol cue exposure between alcoholic subjects and social drinkers, we designed a functional magnetic resonance imaging (fMRI) protocol involving alcohol-specific cues. Ten non-treatment-seeking adult alcoholic subjects (2 women) (mean [SD] age, 29.9 [9.9] years) as well as 10 healthy social drinking controls of similar age (2 women) (mean [SD] age, 29.4 [8.9] years) were recruited, screened, and scanned. In the 1.5-T magnetic resonance imaging scanner, subjects were serially rated for alcohol craving before and after a sip of alcohol, and after a 9-minute randomized presentation of pictures of alcoholic beverages, control nonalcoholic beverages, and 2 different visual control tasks. During picture presentation, changes in regional brain activity were measured with the blood oxygen level-dependent technique. Alcoholic subjects, compared with the social drinking subjects, reported higher overall craving ratings for alcohol. After a sip of alcohol, while viewing alcohol cues compared with viewing other beverage cues, only the alcoholic subjects had increased activity in the left dorsolateral prefrontal cortex and the anterior thalamus. The social drinkers exhibited specific activation only while viewing the control beverage pictures. When exposed to alcohol cues, alcoholic subjects have increased brain activity in the prefrontal cortex and anterior thalamus-brain regions associated with emotion regulation, attention, and appetitive behavior.