Auditory stimuli elicit hippocampal neuronal responses during sleep

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Ekaterina eVinnik

2012-06-01

Full Text Available To investigate how hippocampal neurons code behaviorally salient stimuli, we recorded from neurons in the CA1 region of hippocampus in rats while they learned to associate the presence of sound with water reward. Rats learned to alternate between two reward ports at which, in 50 percent of the trials, sound stimuli were presented followed by water reward after a 3-second delay. Sound at the water port predicted subsequent reward delivery in 100 percent of the trials and the absence of sound predicted reward omission. During this task, 40% of recorded neurons fired differently according to which of the 2 reward ports the rat was visiting. A smaller fraction of neurons demonstrated onset response to sound/nosepoke (19% and reward delivery (24%. When the sounds were played during passive wakefulness, 8% of neurons responded with short latency onset responses; 25% of neurons responded to sounds when they were played during sleep. Based on the current findings and the results of previous experiments we propose the existence of two types of hippocampal neuronal responses to sounds: sound-onset responses with very short latency and longer-lasting sound-specific responses that are likely to be present when the animal is actively engaged in the task. During sleep the short-latency responses in hippocampus are intermingled with sustained activity which in the current experiment was detected for 1-2 seconds.

Sex-related memory recall and talkativeness for emotional stimuli

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Benedetto eArnone

2011-09-01

Full Text Available Recent studies have evidenced an increasing interest in sex-related brain mechanisms and cerebral lateralization subserving emotional memory, language processing, and conversational behavior. We used event related potentials (ERP to examine the influence of sex and hemisphere on brain responses to emotional stimuli. Given that the P300 component of ERP is considered a cognitive neuroelectric phenomenon, we compared left and right hemisphere P300 responses to emotional stimuli in men and women. As indexed by both amplitude and latency measures, emotional stimuli elicited more robust P300 effects in the left hemisphere in women than in men, while a stronger P300 component was elicited in the right hemisphere in men compared to women. Our findings show that the variables of sex and hemisphere interacted significantly to influence the strength of the P300 component to the emotional stimuli. Emotional stimuli were also best recalled when given a long-term, incidental memory test, a fact potentially related to the differential P300 waves at encoding. Moreover, taking into account the sex-related differences in language processing and conversational behaviour, in the present study we evaluated possible talkativeness differences between the two genders in the recollection of emotional stimuli. Our data showed that women used a higher number of words, compared to men, to describe both arousal and neutral stories. Moreover, the present results support the view that sex differences in lateralization may not be a general feature of language processing but may be related to the specific condition, such as the emotional content of stimuli.

Emotion elicitation: A comparison of pictures and films

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Meike Katrin Uhrig

2016-02-01

Full Text Available AbstractPictures and film clips are widely used and accepted stimuli to elicit emotions. Based on theoretical arguments it is often assumed that the emotional effects of films exceed those of pictures, but to date this assumption has not been investigated directly. The aim of the present study was to compare pictures and films in terms of their capacity to induce emotions verified by means of explicit measures. Stimuli were (a single pictures presented for 6 s, (b a set of three consecutive pictures with emotionally congruent contents presented for 2 s each, (c short film clips with a duration of 6 s. A total of 144 participants rated their emotion and arousal states following stimulus presentation. Repeated-measures ANOVAs revealed that the film clips and 3-picture version were as effective as the classical 1-picture method to elicit positive emotions, however, modulation towards positive valence was little. Modulation toward negative valence was more effective in general. Film clips were less effective than pictorial stimuli in producing the corresponding emotion states (all p < .001 and were less arousing (all p ≤ .02. Possible reasons for these unexpected results are discussed.

Emotion Elicitation: A Comparison of Pictures and Films.

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Uhrig, Meike K; Trautmann, Nadine; Baumgärtner, Ulf; Treede, Rolf-Detlef; Henrich, Florian; Hiller, Wolfgang; Marschall, Susanne

2016-01-01

Pictures and film clips are widely used and accepted stimuli to elicit emotions. Based on theoretical arguments it is often assumed that the emotional effects of films exceed those of pictures, but to date this assumption has not been investigated directly. The aim of the present study was to compare pictures and films in terms of their capacity to induce emotions verified by means of explicit measures. Stimuli were (a) single pictures presented for 6 s, (b) a set of three consecutive pictures with emotionally congruent contents presented for 2 s each, (c) short film clips with a duration of 6 s. A total of 144 participants rated their emotion and arousal states following stimulus presentation. Repeated-measures ANOVAs revealed that the film clips and 3-picture version were as effective as the classical 1-picture method to elicit positive emotions, however, modulation toward positive valence was little. Modulation toward negative valence was more effective in general. Film clips were less effective than pictorial stimuli in producing the corresponding emotion states (all p < 0.001) and were less arousing (all p ≤ 0.02). Possible reasons for these unexpected results are discussed.

N400 elicited by incongruent ending words of Chinese idioms in healthy adults.

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Chen, Xing-shi; Tang, Yun-xiang; Xiao, Ze-ping; Wang, Ji-jun; Zhang, Ming-dao; Zhang, Zai-fu; Hu, Zhen-yu; Lou, Fei-ying; Chen, Chong; Zhang, Tian-hong

2010-03-20

Prior research about N400 has been mainly based on English stimuli, while the cognitive processing of Chinese characters is still unclear. The aim of the present study was to further investigate the semantic processing of Chinese idioms. Event related potentials (ERP) component N400 was elicited by 38 pairs of matching (congruent) and mismatching (incongruent) ended Chinese idioms: ending words with same phoneme but different shape and meaning (sPdSdM), with similar shape but different phoneme and meaning (sSdPdM), with same meaning but different phoneme and shape (sMdPdS), and words with different phoneme, shape and meaning (dPdSdM) and recorded by Guangzhou Runjie WJ-1 ERP instruments. In 62 right-handed healthy adults (age 19 - 50 years), N400 amplitudes and latencies were compared between matching and mismatching conditions at Fz, Cz and Pz. N400 showed a midline distribution and could be elicited in electrodes Fz, Cz and Pz. The mean values of N400 latencies and amplitudes were obtained for matching and mismatching ending words in healthy adults. Significant differences were found in N400 latencies and amplitudes in matching and mismatching ending-words idioms in healthy adults (P idioms, N400 latencies were prolonged and the amplitudes were increased in mismatching ones. N400s elicited by different types of stimuli showed different latencies and amplitudes, and longest N400 latency and largest N400 amplitude were elicited by ending-words with dPdSdM. No gender difference was found of N400 latency and amplitude in this study (P > 0.05). Compared with English stimuli, Chinese ideographic words could provide more flexible stimuli for N400 research in that the words have 3-dimension changes - phoneme, shape and meaning. Features of N400 elicited by matching and mismatching ending words in Chinese idioms are mainly determined by the meaning of the word. Some issues of N400 elicited by Chinese characters deserve further research.

Dissociating object-based from egocentric transformations in mental body rotation: effect of stimuli size.

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Habacha, Hamdi; Moreau, David; Jarraya, Mohamed; Lejeune-Poutrain, Laure; Molinaro, Corinne

2018-01-01

The effect of stimuli size on the mental rotation of abstract objects has been extensively investigated, yet its effect on the mental rotation of bodily stimuli remains largely unexplored. Depending on the experimental design, mentally rotating bodily stimuli can elicit object-based transformations, relying mainly on visual processes, or egocentric transformations, which typically involve embodied motor processes. The present study included two mental body rotation tasks requiring either a same-different or a laterality judgment, designed to elicit object-based or egocentric transformations, respectively. Our findings revealed shorter response times for large-sized stimuli than for small-sized stimuli only for greater angular disparities, suggesting that the more unfamiliar the orientations of the bodily stimuli, the more stimuli size affected mental processing. Importantly, when comparing size transformation times, results revealed different patterns of size transformation times as a function of angular disparity between object-based and egocentric transformations. This indicates that mental size transformation and mental rotation proceed differently depending on the mental rotation strategy used. These findings are discussed with respect to the different spatial manipulations involved during object-based and egocentric transformations.

Signaling added response-independent reinforcement to assess Pavlovian processes in resistance to change and relapse.

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Podlesnik, Christopher A; Fleet, James D

2014-09-01

Behavioral momentum theory asserts Pavlovian stimulus-reinforcer relations govern the persistence of operant behavior. Specifically, resistance to conditions of disruption (e.g., extinction, satiation) reflects the relation between discriminative stimuli and the prevailing reinforcement conditions. The present study assessed whether Pavlovian stimulus-reinforcer relations govern resistance to disruption in pigeons by arranging both response-dependent and -independent food reinforcers in two components of a multiple schedule. In one component, discrete-stimulus changes preceded response-independent reinforcers, paralleling methods that reduce Pavlovian conditioned responding to contextual stimuli. Compared to the control component with no added stimuli preceding response-independent reinforcement, response rates increased as discrete-stimulus duration increased (0, 5, 10, and 15 s) across conditions. Although resistance to extinction decreased as stimulus duration increased in the component with the added discrete stimulus, further tests revealed no effect of discrete stimuli, including other disrupters (presession food, intercomponent food, modified extinction) and reinstatement designed to control for generalization decrement. These findings call into question a straightforward conception that the stimulus-reinforcer relations governing resistance to disruption reflect the same processes as Pavlovian conditioning, as asserted by behavioral momentum theory. © Society for the Experimental Analysis of Behavior.

Monetary reward modulates task-irrelevant perceptual learning for invisible stimuli.

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Pascucci, David; Mastropasqua, Tommaso; Turatto, Massimo

2015-01-01

Task Irrelevant Perceptual Learning (TIPL) shows that the brain's discriminative capacity can improve also for invisible and unattended visual stimuli. It has been hypothesized that this form of "unconscious" neural plasticity is mediated by an endogenous reward mechanism triggered by the correct task performance. Although this result has challenged the mandatory role of attention in perceptual learning, no direct evidence exists of the hypothesized link between target recognition, reward and TIPL. Here, we manipulated the reward value associated with a target to demonstrate the involvement of reinforcement mechanisms in sensory plasticity for invisible inputs. Participants were trained in a central task associated with either high or low monetary incentives, provided only at the end of the experiment, while subliminal stimuli were presented peripherally. Our results showed that high incentive-value targets induced a greater degree of perceptual improvement for the subliminal stimuli, supporting the role of reinforcement mechanisms in TIPL.

Origins of altered reinforcement effects in ADHD

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Tripp Gail

2009-02-01

Full Text Available Abstract Attention-deficit/hyperactivity disorder (ADHD, characterized by hyperactivity, impulsiveness and deficient sustained attention, is one of the most common and persistent behavioral disorders of childhood. ADHD is associated with catecholamine dysfunction. The catecholamines are important for response selection and memory formation, and dopamine in particular is important for reinforcement of successful behavior. The convergence of dopaminergic mesolimbic and glutamatergic corticostriatal synapses upon individual neostriatal neurons provides a favorable substrate for a three-factor synaptic modification rule underlying acquisition of associations between stimuli in a particular context, responses, and reinforcers. The change in associative strength as a function of delay between key stimuli or responses, and reinforcement, is known as the delay of reinforcement gradient. The gradient is altered by vicissitudes of attention, intrusions of irrelevant events, lapses of memory, and fluctuations in dopamine function. Theoretical and experimental analyses of these moderating factors will help to determine just how reinforcement processes are altered in ADHD. Such analyses can only help to improve treatment strategies for ADHD.

Neuronal Activation in the Medulla Oblongata during Selective Elicitation of the Laryngeal Adductor Response

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Ambalavanar, Ranjinidevi; Tanaka, Yasumasa; Selbie, W. Scott; Ludlow, Christy L.

2008-01-01

Swallow and cough are complex motor patterns elicited by rapid and intense electrical stimulation of the internal branch of the superior laryngeal nerve (ISLN). The laryngeal adductor response (LAR) includes only a laryngeal response, is elicited by single stimuli to the ISLN, and is thought to represent the brain stem pathway involved in laryngospasm. To identify which regions in the medulla are activated during elicitation of the LAR alone, single electrical stimuli were presented once every 2 s to the ISLN. Two groups of 5 cats each were studied; an experimental group with unilateral ISLN stimulation at 0.5 Hz and a surgical control group. Three additional cats were studied to evaluate whether other oral, pharyngeal or respiratory muscles were activated during ISLN stimulation eliciting LAR. We quantified up to 22 sections for each of 14 structures in the medulla to determine if regions had increased Fos-like immunoreactive neurons in the experimental group. Significant increases (p medulla. PMID:15212423

Responding for sucrose and wheel-running reinforcement: effects of sucrose concentration and wheel-running reinforcer duration.

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Belke, Terry W; Hancock, Stephanie D

2003-03-01

Six male albino rats were placed in running wheels and exposed to a fixed-interval 30-s schedule of lever pressing that produced either a drop of sucrose solution or the opportunity to run for a fixed duration as reinforcers. Each reinforcer type was signaled by a different stimulus. In Experiment 1, the duration of running was held constant at 15 s while the concentration of sucrose solution was varied across values of 0, 2.5. 5, 10, and 15%. As concentration decreased, postreinforcement pause duration increased and local rates decreased in the presence of the stimulus signaling sucrose. Consequently, the difference between responding in the presence of stimuli signaling wheel-running and sucrose reinforcers diminished, and at 2.5%, response functions for the two reinforcers were similar. In Experiment 2, the concentration of sucrose solution was held constant at 15% while the duration of the opportunity to run was first varied across values of 15, 45, and 90 s then subsequently across values of 5, 10, and 15 s. As run duration increased, postreinforcement pause duration in the presence of the wheel-running stimulus increased and local rates increased then decreased. In summary, inhibitory aftereffects of previous reinforcers occurred when both sucrose concentration and run duration varied; changes in responding were attributable to changes in the excitatory value of the stimuli signaling the two reinforcers.

Monetary reward modulates task-irrelevant perceptual learning for invisible stimuli.

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David Pascucci

Full Text Available Task Irrelevant Perceptual Learning (TIPL shows that the brain's discriminative capacity can improve also for invisible and unattended visual stimuli. It has been hypothesized that this form of "unconscious" neural plasticity is mediated by an endogenous reward mechanism triggered by the correct task performance. Although this result has challenged the mandatory role of attention in perceptual learning, no direct evidence exists of the hypothesized link between target recognition, reward and TIPL. Here, we manipulated the reward value associated with a target to demonstrate the involvement of reinforcement mechanisms in sensory plasticity for invisible inputs. Participants were trained in a central task associated with either high or low monetary incentives, provided only at the end of the experiment, while subliminal stimuli were presented peripherally. Our results showed that high incentive-value targets induced a greater degree of perceptual improvement for the subliminal stimuli, supporting the role of reinforcement mechanisms in TIPL.

The detrimental effects of extrinsic reinforcement on "Intrinsic motivation".

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Dickinson, A M

1989-01-01

Extrinsic consequences have been criticized on the grounds that they decrease intrinsic motivation or internally initiated behavior. Two popular rationales for this criticism, Lepper's overjustification hypothesis (1981) and Deci's motivational theory (Deci & Ryan, 1985), are reviewed and the criticism is then redefined behaviorally. "Intrinsically controlled" behavior is defined as behavior maintained by response-produced reinforcers, and the question concerning extrinsic consequences is thus restated as follows: When behavior is maintained by response-produced stimuli, does extrinsic reinforcement decrease the reinforcing value of those stimuli? The empirical support for this detrimental effect is summarized briefly, and several possible explanations for the phenomenon are offered. Research results that reflect on the effect's generality and social significance are discussed next, with the conclusion that the effect is transient and not likely to occur at all if extrinsic rewards are reinforcing, noncompetitive, based on reasonable performance standards, and delivered repetitively.

Steady-state VEP responses to uncomfortable stimuli.

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O'Hare, Louise

2017-02-01

Periodic stimuli, such as op-art, can evoke a range of aversive sensations included in the term visual discomfort. Illusory motion effects are elicited by fixational eye movements, but the cortex might also contribute to effects of discomfort. To investigate this possibility, steady-state visually evoked responses (SSVEPs) to contrast-matched op-art-based stimuli were measured at the same time as discomfort judgements. On average, discomfort reduced with increasing spatial frequency of the pattern. In contrast, the peak amplitude of the SSVEP response was around the midrange spatial frequencies. Like the discomfort judgements, SSVEP responses to the highest spatial frequencies were lowest amplitude, but the relationship breaks down between discomfort and SSVEP for the lower spatial frequency stimuli. This was not explicable by gross eye movements as measured using the facial electrodes. There was a weak relationship between the peak SSVEP responses and discomfort judgements for some stimuli, suggesting that discomfort can be explained in part by electrophysiological responses measured at the level of the cortex. However, there is a breakdown of this relationship in the case of lower spatial frequency stimuli, which remains unexplained. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Gaze-contingent reinforcement learning reveals incentive value of social signals in young children and adults.

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Vernetti, Angélina; Smith, Tim J; Senju, Atsushi

2017-03-15

While numerous studies have demonstrated that infants and adults preferentially orient to social stimuli, it remains unclear as to what drives such preferential orienting. It has been suggested that the learned association between social cues and subsequent reward delivery might shape such social orienting. Using a novel, spontaneous indication of reinforcement learning (with the use of a gaze contingent reward-learning task), we investigated whether children and adults' orienting towards social and non-social visual cues can be elicited by the association between participants' visual attention and a rewarding outcome. Critically, we assessed whether the engaging nature of the social cues influences the process of reinforcement learning. Both children and adults learned to orient more often to the visual cues associated with reward delivery, demonstrating that cue-reward association reinforced visual orienting. More importantly, when the reward-predictive cue was social and engaging, both children and adults learned the cue-reward association faster and more efficiently than when the reward-predictive cue was social but non-engaging. These new findings indicate that social engaging cues have a positive incentive value. This could possibly be because they usually coincide with positive outcomes in real life, which could partly drive the development of social orienting. © 2017 The Authors.

Stimuli-responsive cement-reinforced rubber.

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Musso, Simone; Robisson, Agathe; Maheshwar, Sudeep; Ulm, Franz-Josef

2014-05-14

In this work, we report the successful development of a cement-rubber reactive composite with reversible mechanical properties. Initially, the composite behaves like rubber containing inert filler, but when exposed to water, it increases in volume and reaches a stiffness that is intermediate between that of hydrogenated nitrile butadiene rubber (HNBR) and hydrated cement, while maintaining a relatively large ductility characteristic of rubber. After drying, the modulus increases even further up to 400 MPa. Wet/drying cycles prove that the elastic modulus can reversibly change between 150 and 400 MPa. Utilizing attenuated total reflection Fourier transform infrared spectroscopy), we demonstrate that the high pH produced by the hydration of cement triggers the hydrolysis of the rubber nitrile groups into carboxylate anions. Thus, the salt bridges, generated between the carboxylate anions of the elastomer and the cations of the filler, are responsible for the reversible variations in volume and elastic modulus of the composite as a consequence of environmental moisture exposure. These results reveal that cement nanoparticles can successfully be used to accomplish a twofold task: (a) achieve an original postpolymerization modification that allows one to work with carboxylate HNBR (HXNBR) not obtained by direct copolymerization of carboxylate monomers with butadiene, and (b) synthesize a stimuli-responsive polymeric composite. This new type of material, having an ideal behavior for sealing application, could be used as an alternative to cement for oil field zonal isolation applications.

Neurocognitive correlates of processing food-related stimuli in a Go/No-go paradigm.

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Watson, Todd D; Garvey, Katherine T

2013-12-01

We examined the neurocognitive correlates of processing food-related stimuli in healthy young adults. Event-related potential (ERP) data were collected while 48 participants completed a computerized Go/No-go task consisting of food and nonfood images. Separately, we assessed participants' self-reported levels of external, restrained, and emotional eating behaviors as well as trait impulsivity, behavioral activation/inhibition, and performance on the Stroop Color-Word Test. We found that across participants, food images elicited significantly enhanced P3(00) and slow-wave ERP components. The difference in slow-wave components elicited by food and nonfood images was correlated with Stroop interference scores. Food images also elicited significantly enhanced N2(00) components, but only in female participants. The difference between N2 components elicited by food and nonfood images was related to body mass index and scores of external eating in females. Overall, these data suggest that processing food-related stimuli recruits distinct patterns of cortical activity, that the magnitude of these effects is related to behavioral and cognitive variables, and that the neurocognitive correlates of processing food-cues may be at least partly dissociable between males and females. Copyright © 2013 Elsevier Ltd. All rights reserved.

Reversal Negativity and Bistable Stimuli: Attention, Awareness, or Something Else?

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Intaite, Monika; Koivisto, Mika; Ruksenas, Osvaldas; Revonsuo, Antti

2010-01-01

Ambiguous (or bistable) figures are visual stimuli that have two mutually exclusive perceptual interpretations that spontaneously alternate with each other. Perceptual reversals, as compared with non-reversals, typically elicit a negative difference called reversal negativity (RN), peaking around 250 ms from stimulus onset. The cognitive…

Resistance to extinction, generalization decrement, and conditioned reinforcement.

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Dulaney, Alana E; Bell, Matthew C

2008-06-01

This study investigated generalization decrement during an extinction resistance-to-change test for pigeon key pecking using a two-component multiple schedule with equal variable-interval 3-min schedules and different reinforcer amounts (one component presented 2-s access to reinforcement and the other 8s). After establishing baseline responding, subjects were assigned to one of the two extinction conditions: hopper stimuli (hopper and hopper light were activated but no food was available) or Control (inactive hopper and hopper light). Responding in the 8-s component was more resistant to extinction than responding in the 2-s component, the hopper stimuli group was more resistant to extinction compared to the Control group, and an interaction between amount of reinforcement, extinction condition, and session block was present. This finding supports generalization decrement as a factor that influences resistance to extinction. Hopper-time data (the amount of time subjects spent with their heads in the hopper) were compared to resistance-to-change data in an investigation of the role of conditioned reinforcement on resistance to change.

The detrimental effects of extrinsic reinforcement on “Intrinsic motivation”

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Dickinson, Alyce M.

1989-01-01

Extrinsic consequences have been criticized on the grounds that they decrease intrinsic motivation or internally initiated behavior. Two popular rationales for this criticism, Lepper's overjustification hypothesis (1981) and Deci's motivational theory (Deci & Ryan, 1985), are reviewed and the criticism is then redefined behaviorally. “Intrinsically controlled” behavior is defined as behavior maintained by response-produced reinforcers, and the question concerning extrinsic consequences is thus restated as follows: When behavior is maintained by response-produced stimuli, does extrinsic reinforcement decrease the reinforcing value of those stimuli? The empirical support for this detrimental effect is summarized briefly, and several possible explanations for the phenomenon are offered. Research results that reflect on the effect's generality and social significance are discussed next, with the conclusion that the effect is transient and not likely to occur at all if extrinsic rewards are reinforcing, noncompetitive, based on reasonable performance standards, and delivered repetitively. PMID:22478013

Differences in Swallowing between High and Low Concentration Taste Stimuli

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Ahmed Nagy

2014-01-01

Full Text Available Taste is a property that is thought to potentially modulate swallowing behavior. Whether such effects depend on taste, intensity remains unclear. This study explored differences in the amplitudes of tongue-palate pressures in swallowing as a function of taste stimulus concentration. Tongue-palate pressures were collected in 80 healthy women, in two age groups (under 40, over 60, stratified by genetic taste status (nontasters, supertasters. Liquids with different taste qualities (sweet, sour, salty, and bitter were presented in high and low concentrations. General labeled magnitude scale ratings captured perceived taste intensity and liking/disliking of the test liquids. Path analysis explored whether factors of taste, concentration, age group, and/or genetic taste status impacted: (1 perceived intensity; (2 palatability; and (3 swallowing pressures. Higher ratings of perceived intensity were found in supertasters and with higher concentrations, which were more liked/disliked than lower concentrations. Sweet stimuli were more palatable than sour, salty, or bitter stimuli. Higher concentrations elicited stronger tongue-palate pressures independently and in association with intensity ratings. The perceived intensity of a taste stimulus varies as a function of stimulus concentration, taste quality, participant age, and genetic taste status and influences swallowing pressure amplitudes. High-concentration salty and sour stimuli elicit the greatest tongue-palate pressures.

N400 elicited by incongruent ending words of Chinese idioms in healthy adults

Institute of Scientific and Technical Information of China (English)

CHEN Xing-shi; ZHANG Tian-hong; TANG Yun-xiang; XIAO Ze-ping; WANG Ji-jun; ZHANG Ming-dao; ZHANG Zai-fu; HU Zhen-yu; LOU Fei-ying; CHEN Chong

2010-01-01

Background Prior research about N400 has been mainly based on English stimuli,while the cognitive.processing of Chinese characters is still unclear.The aim of the present study was to further investigate the semantic processing of Chinese idioms.Methods Event related potentials (ERP) component N400 was elicited by 38 pairs of matching (congruent) and mismatching (incongruent) ended Chinese idioms:ending words with same phoneme but different shape and meaning (sPdSdM),with similar shape but different phoneme and meaning(sSdPdM),with same meaning but different phoneme and shape(sMdPdS),and words with different phoneme,shape and meaning(dPdSdM)and recorded by Guangzhou Runjie WJ-1 ERP instruments.In 62 right-handed healthy adults(age 19-50 years),N400 amplitudes and latencies were compared between matching and mismatching conditions at Fz,Cz and Pz.Results N400 showed a midline distribution and could be elicited in electrodes Fz, Cz and Pz.The mean values of N400 latencies and amplitudes were obtained for matching and mismatching ending werds in healthy adults.Significant differences were found in N400 latencies and amplitudes in matching and mismatching ending-werds idioms in healthy adults(P0.05).Conclusions Compared with English stimuli.Chinese ideographic words could provide more flexible stimuli for N400 research in that the werds have 3-dimension changes-phoneme.shape and meaning.Features of N400 elicited by matching and mismatching ending words in Chinese idioms are mainly determined by the meaning of the werd.Some issues of N400 elicited by Chinese characters deserve further research.

What monitor can replace the cathode-ray tube for visual stimulation to elicit multifocal electroretinograms?

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Matsumoto, Celso Soiti; Shinoda, Kei; Matsumoto, Harue; Seki, Keisuke; Nagasaka, Eiichiro; Iwata, Takeshi; Mizota, Atsushi

2014-08-05

To compare a conventional cathode-ray tube (CRT) screen to organic light-emitting diode (OLED) and liquid crystal display (LCD) screens as visual stimulators to elicit multifocal electroretinograms (mfERGs), mfERGs were recorded from seven eyes of seven healthy volunteers (21 ± 2 years). The mfERGs elicited by a conventional CRT screen (S710, Compaq Computer Co.) were compared to those elicited by a studio-grade master OLED monitor (PVM-1741, Sony, Japan) and a conventional LCD (S1721, Flexscan, Eizo Nanao Corp., Japan). The luminance changes of each monitor were measured with a photodiode. CRT, OLED, and LCD screens with a frame frequency of 60 Hz were studied. A hexagonal stimulus array with 61 stimulus elements was created on each monitor. The serial white stimuli of the OLED screen at 60 Hz did not fuse, and that of the LCD screens fused. The amplitudes of P1 and P2 of the first-order kernels of the mfERGs were not significantly different from those elicited by the CRT and OLED screens, and the P1 amplitude of the first-order kernel elicited by the LCD stimuli was significantly smaller than that elicited by the CRT in all the groups of the averaged hexagonal elements. The implicit times were approximately 10 ms longer in almost all components elicited by the LCD screen compared to those elicited by the CRT screen. The mfERGs elicited by monitors other than the CRT should be carefully interpreted, especially those elicited by LCD screens. The OLED had good performance, and we conclude that it can replace the CRT as a stimulator for mfERGs; however, a collection of normative data is recommended. © 2014 ARVO.

Testing food-related inhibitory control to high- and low-calorie food stimuli: Electrophysiological responses to high-calorie food stimuli predict calorie and carbohydrate intake.

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Carbine, Kaylie A; Christensen, Edward; LeCheminant, James D; Bailey, Bruce W; Tucker, Larry A; Larson, Michael J

2017-07-01

Maintaining a healthy diet has important implications for physical and mental health. One factor that may influence diet and food consumption is inhibitory control-the ability to withhold a dominant response in order to correctly respond to environmental demands. We examined how N2 amplitude, an ERP that reflects inhibitory control processes, differed toward high- and low-calorie food stimuli and related to food intake. A total of 159 participants (81 female; M age = 23.5 years; SD = 7.6) completed two food-based go/no-go tasks (one with high-calorie and one with low-calorie food pictures as no-go stimuli) while N2 amplitude was recorded. Participants recorded food intake using the Automated Self-Administered 24-hour Dietary Recall system. Inhibiting responses toward high-calorie stimuli elicited a larger (i.e., more negative) no-go N2 amplitude; inhibiting responses toward low-calorie stimuli elicited a smaller no-go N2 amplitude. Participants were more accurate during the high-calorie than low-calorie task, but took longer to respond on go trials toward high-calorie rather than low-calorie stimuli. When controlling for age, gender, and BMI, larger high-calorie N2 difference amplitude predicted lower caloric intake (β = 0.17); low-calorie N2 difference amplitude was not related to caloric intake (β = -0.03). Exploratory analyses revealed larger high-calorie N2 difference amplitude predicted carbohydrate intake (β = 0.22), but not protein (β = 0.08) or fat (β = 0.11) intake. Results suggest that withholding responses from high-calorie foods requires increased recruitment of inhibitory control processes, which may be necessary to regulate food consumption, particularly for foods high in calories and carbohydrates. © 2017 Society for Psychophysiological Research.

Ratio of dopamine synthesis capacity to D2 receptor availability in ventral striatum correlates with central processing of affective stimuli

International Nuclear Information System (INIS)

Kienast, Thorsten; Rapp, Michael; Siessmeier, Thomas; Buchholz, Hans G.; Schreckenberger, Mathias; Wrase, Jana; Heinz, Andreas; Braus, Dieter F.; Smolka, Michael N.; Mann, Karl; Roesch, Frank; Cumming, Paul; Gruender, Gerhard; Bartenstein, Peter

2008-01-01

Dopaminergic neurotransmission in the ventral striatum may interact with limbic processing of affective stimuli, whereas dorsal striatal dopaminergic neurotransmission can affect habitual processing of emotionally salient stimuli in the pre-frontal cortex. We investigated the dopaminergic neurotransmission in the ventral and dorsal striatum with respect to central processing of affective stimuli in healthy subjects. Subjects were investigated with positron emission tomography and [ 18 F]DOPA for measurements of dopamine synthesis capacity and [ 18 F]DMFP for estimation of dopamine D2 receptor binding potential. Functional magnetic resonance imaging was used to assess the blood-oxygen-level-dependent (BOLD) response to affective pictures, which was correlated with the ratio of [ 18 F]DOPA net influx constant K in app /[ 18 F]DMFP-binding potential (BP N D) in the ventral and dorsal striatum. The magnitude of the ratio in the ventral striatum was positively correlated with BOLD signal increases elicited by negative versus neutral pictures in the right medial frontal gyrus (BA10), right inferior parietal lobe and left post-central gyrus. In the dorsal striatum, the ratio was positively correlated with BOLD signal activation elicited by negative versus neutral stimuli in the left post-central gyrus. The BOLD signal elicited by positive versus neutral stimuli in the superior parietal gyrus was positively correlated with the dorsal and ventral striatal ratio. The correlations of the ratio in the ventral and dorsal striatum with processing of affective stimuli in the named cortical regions support the hypothesis that dopamine transmission in functional divisions of the striatum modulates processing of affective stimuli in specific cortical areas. (orig.)

P1 and N170 components distinguish human-like and animal-like makeup stimuli.

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Luo, Shuwei; Luo, Wenbo; He, Weiqi; Chen, Xu; Luo, Yuejia

2013-06-19

This study used event-related potentials to investigate the sensitivity of P1 and N170 components to human-like and animal-like makeup stimuli, which were derived from pictures of Peking opera characters. As predicted, human-like makeup stimuli elicited larger P1 and N170 amplitudes than did animal-like makeup stimuli. Interestingly, a right hemisphere advantage was observed for human-like but not for animal-like makeup stimuli. Dipole source analyses of 130-200-ms window showed that the bilateral fusiform face area may contribute to the differential sensitivity of the N170 component in response to human-like and animal-like makeup stimuli. The present study suggests that the amplitudes of both the P1 and the N170 are sensitive for the mouth component of face-like stimuli.

Event-related potentials elicited by social commerce and electronic-commerce reviews.

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Bai, Yan; Yao, Zhong; Cong, Fengyu; Zhang, Linlin

2015-12-01

There is an increasing interest regarding the use of electroencephalography (EEG) in social commerce and electronic commerce (e-commerce) research. There are several reviews in the field of social commerce or e-commerce; these have great potential value and mining them is fundamental and significant. To our knowledge, EEG is rarely applied to study these. In this study, we examined the neural correlates of social commerce reviews (SCRs) and e-commerce reviews (ECRs) by using them as stimuli to evoke event-related potentials. All SCRs were from friends through a social media platform, whereas ECRs were from strangers through an e-commerce platform. The experimental design was similar to that of a priming paradigm, and included 40 pairs of stimuli consisting of product information (prime stimulus) and reviews (target stimulus). The results showed that the P300 component was successfully evoked by SCR and ECR stimuli. Moreover, the P300 components elicited by SCRs had higher amplitudes than those elicited by ECRs. These findings indicate that participants paid more attention to SCRs than to ECRs. In addition, the associations between neural responses and reviews in social commerce have the potential to assist companies in studying consumer behaviors, thus permitting them to enhance their social commerce strategies.

Examination of the Influence of Contingency on Changes in Reinforcer Value

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DeLeon, Iser G.; Gregory, Meagan K.; Frank-Crawford, Michelle A.; Allman, Melissa J.; Wilke, Arthur E.; Carreau-Webster, Abbey B.; Triggs, Mandy M.

2011-01-01

This study examined how the amount of effort required to produce a reinforcer influenced subsequent preference for, and strength of, that reinforcer in 7 individuals with intellectual disabilities. Preference assessments identified four moderately preferred stimuli for each participant, and progressive-ratio (PR) analyses indexed reinforcer…

Reinforcing and discriminative stimulus properties of music in goldfish.

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Shinozuka, Kazutaka; Ono, Haruka; Watanabe, Shigeru

2013-10-01

This paper investigated whether music has reinforcing and discriminative stimulus properties in goldfish. Experiment 1 examined the discriminative stimulus properties of music. The subjects were successfully trained to discriminate between two pieces of music--Toccata and Fugue in D minor (BWV 565) by J. S. Bach and The Rite of Spring by I. Stravinsky. Experiment 2 examined the reinforcing properties of sounds, including BWV 565 and The Rite of Spring. We developed an apparatus for measuring spontaneous sound preference in goldfish. Music or noise stimuli were presented depending on the subject's position in the aquarium, and the time spent in each area was measured. The results indicated that the goldfish did not show consistent preferences for music, although they showed significant avoidance of noise stimuli. These results suggest that music has discriminative but not reinforcing stimulus properties in goldfish. Copyright © 2013 Elsevier B.V. All rights reserved.

Elucidating the role of D4 receptors in mediating attributions of salience to incentive stimuli on Pavlovian conditioned approach and conditioned reinforcement paradigms.

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Cocker, P J; Vonder Haar, C; Winstanley, C A

2016-10-01

The power of drug-associated cues to instigate drug 'wanting' and consequently promote drug seeking is a corner stone of contemporary theories of addiction. Gambling disorder has recently been added to the pantheon of addictive disorders due to the phenomenological similarities between the diseases. However, the neurobiological mechanism that may mediate increased sensitivity towards conditioned stimuli in addictive disorders is unclear. We have previously demonstrated using a rodent analogue of a simple slot machine that the dopamine D4 receptor is critically engaged in controlling animals' attribution of salience to stimuli associated with reward in this paradigm, and consequently may represent a target for the treatment of gambling disorder. Here, we investigated the role of acute administration of a D4 receptor agonist on animals' responsivity to conditioned stimuli on both a Pavlovian conditioned approach (autoshaping) and a conditioned reinforcement paradigm. Following training on one of the two tasks, separate cohorts of rats (male and female) were administered a dose of PD168077 shown to be maximally effective at precipitating errors in reward expectancy on the rat slot machine task (10mg/kg). However, augmenting the activity of the D4 receptors in this manner did not alter behaviour on either task. These data therefore provide novel evidence that the D4 receptor does not alter incentive motivation in response to cues on simple behavioural tasks. Copyright © 2016 Elsevier B.V. All rights reserved.

Event-related potentials elicited by pre-attentive emotional changes in temporal context.

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Tomomi Fujimura

Full Text Available The ability to detect emotional change in the environment is essential for adaptive behavior. The current study investigated whether event-related potentials (ERPs can reflect emotional change in a visual sequence. To assess pre-attentive processing, we examined visual mismatch negativity (vMMN: the negative potentials elicited by a deviant (infrequent stimulus embedded in a sequence of standard (frequent stimuli. Participants in two experiments pre-attentively viewed visual sequences of Japanese kanji with different emotional connotations while ERPs were recorded. The visual sequence in Experiment 1 consisted of neutral standards and two types of emotional deviants with a strong and weak intensity. Although the results indicated that strongly emotional deviants elicited more occipital negativity than neutral standards, it was unclear whether these negativities were derived from emotional deviation in the sequence or from the emotional significance of the deviants themselves. In Experiment 2, the two identical emotional deviants were presented against different emotional standards. One type of deviants was emotionally incongruent with the standard and the other type of deviants was emotionally congruent with the standard. The results indicated that occipital negativities elicited by deviants resulted from perceptual changes in a visual sequence at a latency of 100-200 ms and from emotional changes at latencies of 200-260 ms. Contrary to the results of the ERP experiment, reaction times to deviants showed no effect of emotional context; negative stimuli were consistently detected more rapidly than were positive stimuli. Taken together, the results suggest that brain signals can reflect emotional change in a temporal context.

Dual Effects on Choice of Conditioned Reinforcement Frequency and Conditioned Reinforcement Value

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McDevitt, Margaret A.; Williams, Ben A.

2010-01-01

Pigeons were presented with a concurrent-chains schedule in which the total time to primary reinforcement was equated for the two alternatives (VI 30 s VI 60 s vs. VI 60 s VI 30 s). In one set of conditions, the terminal links were signaled by the same stimulus, and in another set of conditions they were signaled by different stimuli. Choice was…

Intranasal oxytocin enhances socially-reinforced learning in rhesus monkeys

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Lisa A Parr

2014-09-01

Full Text Available There are currently no drugs approved for the treatment of social deficits associated with autism spectrum disorders (ASD. One hypothesis for these deficits is that individuals with ASD lack the motivation to attend to social cues because those cues are not implicitly rewarding. Therefore, any drug that could enhance the rewarding quality of social stimuli could have a profound impact on the treatment of ASD, and other social disorders. Oxytocin (OT is a neuropeptide that has been effective in enhancing social cognition and social reward in humans. The present study examined the ability of OT to selectively enhance learning after social compared to nonsocial reward in rhesus monkeys, an important species for modeling the neurobiology of social behavior in humans. Monkeys were required to learn an implicit visual matching task after receiving either intranasal (IN OT or Placebo (saline. Correct trials were rewarded with the presentation of positive and negative social (play faces/threat faces or nonsocial (banana/cage locks stimuli, plus food. Incorrect trials were not rewarded. Results demonstrated a strong effect of socially-reinforced learning, monkeys’ performed significantly better when reinforced with social versus nonsocial stimuli. Additionally, socially-reinforced learning was significantly better and occurred faster after IN-OT compared to placebo treatment. Performance in the IN-OT, but not Placebo, condition was also significantly better when the reinforcement stimuli were emotionally positive compared to negative facial expressions. These data support the hypothesis that OT may function to enhance prosocial behavior in primates by increasing the rewarding quality of emotionally positive, social compared to emotionally negative or nonsocial images. These data also support the use of the rhesus monkey as a model for exploring the neurobiological basis of social behavior and its impairment.

Evaluating the Influence of Chromatic and Luminance Stimuli on SSVEPs from Behind-the-Ears and Occipital Areas

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Alan Floriano

2018-02-01

Full Text Available This work presents a study of chromatic and luminance stimuli in low-, medium-, and high-frequency stimulation to evoke steady-state visual evoked potential (SSVEP in the behind-the-ears area. Twelve healthy subjects participated in this study. The electroencephalogram (EEG was measured on occipital (Oz and left and right temporal (TP9 and TP10 areas. The SSVEP was evaluated in terms of amplitude, signal-to-noise ratio (SNR, and detection accuracy using power spectral density analysis (PSDA, canonical correlation analysis (CCA, and temporally local multivariate synchronization index (TMSI methods. It was found that stimuli based on suitable color and luminance elicited stronger SSVEP in the behind-the-ears area, and that the response of the SSVEP was related to the flickering frequency and the color of the stimuli. Thus, green-red stimulus elicited the highest SSVEP in medium-frequency range, and green-blue stimulus elicited the highest SSVEP in high-frequency range, reaching detection accuracy rates higher than 80%. These findings will aid in the development of more comfortable, accurate and stable BCIs with electrodes positioned on the behind-the-ears (hairless areas.

Sign-tracking (autoshaping) in rats: a comparison of cocaine and food as unconditioned stimuli.

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Kearns, David N; Weiss, Stanley J

2004-11-01

A series of experiments was performed to determine whether sign-tracking would occur in rats with intravenous (i.v.) cocaine as the unconditioned stimulus. In Experiment 1, a retractable lever paired with food produced strong sign-tracking, but a lever paired with one of three doses of i.v. cocaine did not elicit any approach or contact behavior. Experiment 2 demonstrated that doses of cocaine that did not elicit sign-tracking would function as a positive reinforcer for a lever contact operant. In Experiment 3, an artificial consummatory response was added to make the cocaine reinforcement episode more behaviorally comparable to that occasioned by food. Although the rats readily performed this response when it was required to receive cocaine infusions, they still did not contact a lever that signaled the availability of these infusions. It appears that cocaine is different from other positive reinforcers (e.g., food, water, warmth, or intracranial stimulation) in that it will not produce sign-tracking in rats.

Pedophilic brain potential responses to adult erotic stimuli.

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Knott, Verner; Impey, Danielle; Fisher, Derek; Delpero, Emily; Fedoroff, Paul

2016-02-01

Cognitive mechanisms associated with the relative lack of sexual interest in adults by pedophiles are poorly understood and may benefit from investigations examining how the brain processes adult erotic stimuli. The current study used event-related brain potentials (ERP) to investigate the time course of the explicit processing of erotic, emotional, and neutral pictures in 22 pedophilic patients and 22 healthy controls. Consistent with previous studies, early latency anterior ERP components were highly selective for erotic pictures. Although the ERPs elicited by emotional stimuli were similar in patients and controls, an early frontal positive (P2) component starting as early as 185 ms was significantly attenuated and slow to onset in pedophilia, and correlated with a clinical measure of cognitive distortions. Failure of rapid attentional capture by erotic stimuli suggests a relative reduction in early processing in pedophilic patients which may be associated with relatively diminished sexual interest in adults. Copyright © 2016. Published by Elsevier B.V.

Reproducibility and discriminability of brain patterns of semantic categories enhanced by congruent audiovisual stimuli.

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Yuanqing Li

Full Text Available One of the central questions in cognitive neuroscience is the precise neural representation, or brain pattern, associated with a semantic category. In this study, we explored the influence of audiovisual stimuli on the brain patterns of concepts or semantic categories through a functional magnetic resonance imaging (fMRI experiment. We used a pattern search method to extract brain patterns corresponding to two semantic categories: "old people" and "young people." These brain patterns were elicited by semantically congruent audiovisual, semantically incongruent audiovisual, unimodal visual, and unimodal auditory stimuli belonging to the two semantic categories. We calculated the reproducibility index, which measures the similarity of the patterns within the same category. We also decoded the semantic categories from these brain patterns. The decoding accuracy reflects the discriminability of the brain patterns between two categories. The results showed that both the reproducibility index of brain patterns and the decoding accuracy were significantly higher for semantically congruent audiovisual stimuli than for unimodal visual and unimodal auditory stimuli, while the semantically incongruent stimuli did not elicit brain patterns with significantly higher reproducibility index or decoding accuracy. Thus, the semantically congruent audiovisual stimuli enhanced the within-class reproducibility of brain patterns and the between-class discriminability of brain patterns, and facilitate neural representations of semantic categories or concepts. Furthermore, we analyzed the brain activity in superior temporal sulcus and middle temporal gyrus (STS/MTG. The strength of the fMRI signal and the reproducibility index were enhanced by the semantically congruent audiovisual stimuli. Our results support the use of the reproducibility index as a potential tool to supplement the fMRI signal amplitude for evaluating multimodal integration.

Ratio of dopamine synthesis capacity to D2 receptor availability in ventral striatum correlates with central processing of affective stimuli

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Kienast, Thorsten; Rapp, Michael [Charite Campus Mitte, Department of Psychiatry and Psychotherapy of the Charite University Medical Center, Berlin (Germany); Siessmeier, Thomas; Buchholz, Hans G.; Schreckenberger, Mathias [University of Mainz, Department of Nuclear Medicine, Mainz (Germany); Wrase, Jana; Heinz, Andreas [Charite Campus Mitte, Department of Psychiatry and Psychotherapy of the Charite University Medical Center, Berlin (Germany); Central Institute of Mental Health, Mannheim (Germany); Braus, Dieter F. [University of Hamburg, Neuroimage Nord, Department of Psychiatry, Hamburg (Germany); Smolka, Michael N.; Mann, Karl [Central Institute of Mental Health, Mannheim (Germany); Roesch, Frank [University of Mainz, Institute of Nuclear Chemistry, Mainz (Germany); Cumming, Paul [PET Center and Center for Functionally Integrative Neuroscience, Aarhus (Denmark); Gruender, Gerhard [Aachen University Medical Center, Department of Psychiatry of the RWTH, Mainz (Germany); Bartenstein, Peter [Ludwig-Maximilians-University, Department of Nuclear Medicine, Munich (Germany)

2008-06-15

Dopaminergic neurotransmission in the ventral striatum may interact with limbic processing of affective stimuli, whereas dorsal striatal dopaminergic neurotransmission can affect habitual processing of emotionally salient stimuli in the pre-frontal cortex. We investigated the dopaminergic neurotransmission in the ventral and dorsal striatum with respect to central processing of affective stimuli in healthy subjects. Subjects were investigated with positron emission tomography and [{sup 18}F]DOPA for measurements of dopamine synthesis capacity and [{sup 18}F]DMFP for estimation of dopamine D2 receptor binding potential. Functional magnetic resonance imaging was used to assess the blood-oxygen-level-dependent (BOLD) response to affective pictures, which was correlated with the ratio of [{sup 18}F]DOPA net influx constant K{sub in}{sup app} /[{sup 18}F]DMFP-binding potential (BP{sub N}D) in the ventral and dorsal striatum. The magnitude of the ratio in the ventral striatum was positively correlated with BOLD signal increases elicited by negative versus neutral pictures in the right medial frontal gyrus (BA10), right inferior parietal lobe and left post-central gyrus. In the dorsal striatum, the ratio was positively correlated with BOLD signal activation elicited by negative versus neutral stimuli in the left post-central gyrus. The BOLD signal elicited by positive versus neutral stimuli in the superior parietal gyrus was positively correlated with the dorsal and ventral striatal ratio. The correlations of the ratio in the ventral and dorsal striatum with processing of affective stimuli in the named cortical regions support the hypothesis that dopamine transmission in functional divisions of the striatum modulates processing of affective stimuli in specific cortical areas. (orig.)

Observing Responses and Serial Stimuli: Searching for the Reinforcing Properties of the S-

Science.gov (United States)

Escobar, Rogelio; Bruner, Carlos A.

2009-01-01

The control exerted by a stimulus associated with an extinction component (S-) on observing responses was determined as a function of its temporal relation with the onset of the reinforcement component (S+). Lever pressing by rats was reinforced on a mixed random-interval extinction schedule. Each press on a second lever produced stimuli…

Acquisition with partial and continuous reinforcement in pigeon autoshaping.

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Gottlieb, Daniel A

2004-08-01

Contemporary time accumulation models make the unique prediction that acquisition of a conditioned response will be equally rapid with partial and continuous reinforcement, if the time between conditioned stimuli is held constant. To investigate this, acquisition of conditioned responding was examined in pigeon autoshaping under conditions of 100% and 25% reinforcement, holding intertrial interval constant. Contrary to what was predicted, evidence for slowed acquisition in partially reinforced animals was observed with several response measures. However, asymptotic performance was superior with 25% reinforcement. A switching of reinforcement contingencies after initial acquisition did not immediately affect responding. After further sessions, partial reinforcement augmented responding, whereas continuous reinforcement did not, irrespective of an animal's reinforcement history. Subsequent training with a novel stimulus maintained the response patterns. These acquisition results generally support associative, rather than time accumulation, accounts of conditioning.

Do event-related potentials to infrequent decrements in duration of auditory stimuli demonstrate a memory trace in man?

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Näätänen, R; Paavilainen, P; Reinikainen, K

1989-12-15

Sequences of identical acoustic stimuli were presented to normal subjects reading a book while event-related brain potentials (ERP) elicited by these stimuli were recorded. Occasional irrelevant decreases and increases in stimulus duration elicited an ERP component called the mismatch negativity (MMN). This component was larger over the right hemisphere irrespective of the ear stimulated. These data implicate memory representations which develop automatically and represent the physical features of the repetitive stimulus accurately. Further, when an input does not match with such a trace the MMN is generated. The memory traces involved appear to be those of the acoustic sensory memory, the 'echoic' memory.

PARTIAL REINFORCEMENT (ACQUISITION) EFFECTS WITHIN SUBJECTS.

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AMSEL, A; MACKINNON, J R; RASHOTTE, M E; SURRIDGE, C T

1964-03-01

Acquisition performance of 22 rats in a straight alley runway was examined. The animals were subjected to partial reinforcement when the alley was black (B+/-) and continuous reinforcement when it was white (W+). The results indicated (a) higher terminal performance, for partial as against continuous reinforcement conditions, for starting-time and running-time measures, and (b) lower terminal performance under partial conditions for a goal-entry-time measure. These results confirm within subjects an effect previously demonstrated, in the runway, only in between-groups tests, where one group is run under partial reinforcement and a separate group is run under continuous reinforcement in the presence of the same external stimuli. Differences between the runway situation, employing a discrete-trial procedure and performance measures at three points in the response chain, and the Skinner box situation, used in its free-operant mode with a single performance measure, are discussed in relation to the present findings.

Effects of chemesthetic stimuli mixtures with barium on swallowing apnea duration.

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Todd, J Tee; Butler, Susan G; Plonk, Drew P; Grace-Martin, Karen; Pelletier, Cathy A

2012-10-01

This study tested the hypotheses that swallowing apnea duration (SAD) will increase given barium versus water, chemesthetic stimuli (i.e., water barium, age (older > younger), and genetic taste differences (supertasters > nontasters). Prospective group design. University Medical Center. Eighty healthy women were identified as nontasters and supertasters, equally comprising two age groups: 18 to 35 years and 60+ years. The KayPentax Swallowing Signals Lab was used to acquire SAD via nasal cannula during individually randomized swallows of 5 mL barium, 2.7% w/v citric acid with barium, carbonation with barium, and 50:50 diluted ethanol with barium. Data were analyzed using path analysis, with the mediator of chemesthetic perception, adjusted for repeated measures. Significant main effects of age (P = .012) and chemesthetic stimuli (P = .014) were found, as well as a significant interaction between chemesthetic stimuli and age (P = .028). Older women had a significantly longer SAD than younger women. Post hoc analyses revealed that barium mixed with ethanol elicited a significantly longer SAD than other bolus conditions, regardless of age group. There were no significant differences in SAD between barium and water conditions, and no significant effect of chemesthetic perception (P > .05). Ethanol added to barium elicited longer SAD compared to plain barium, but not the other chemesthetic conditions. Older women had a longer SAD than younger women in all conditions. These findings may influence design of future studies examining effects of various stimuli on SAD. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

Facilitation of responses by task-irrelevant complex deviant stimuli.

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Schomaker, J; Meeter, M

2014-05-01

Novel stimuli reliably attract attention, suggesting that novelty may disrupt performance when it is task-irrelevant. However, under certain circumstances novel stimuli can also elicit a general alerting response having beneficial effects on performance. In a series of experiments we investigated whether different aspects of novelty--stimulus novelty, contextual novelty, surprise, deviance, and relative complexity--lead to distraction or facilitation. We used a version of the visual oddball paradigm in which participants responded to an occasional auditory target. Participants responded faster to this auditory target when it occurred during the presentation of novel visual stimuli than of standard stimuli, especially at SOAs of 0 and 200 ms (Experiment 1). Facilitation was absent for both infrequent simple deviants and frequent complex images (Experiment 2). However, repeated complex deviant images did facilitate responses to the auditory target at the 200 ms SOA (Experiment 3). These findings suggest that task-irrelevant deviant visual stimuli can facilitate responses to an unrelated auditory target in a short 0-200 millisecond time-window after presentation. This only occurs when the deviant stimuli are complex relative to standard stimuli. We link our findings to the novelty P3, which is generated under the same circumstances, and to the adaptive gain theory of the locus coeruleus-norepinephrine system (Aston-Jones and Cohen, 2005), which may explain the timing of the effects. Copyright © 2014 Elsevier B.V. All rights reserved.

Picture book exposure elicits positive visual preferences in toddlers.

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Houston-Price, Carmel; Burton, Eliza; Hickinson, Rachel; Inett, Jade; Moore, Emma; Salmon, Katherine; Shiba, Paula

2009-09-01

Although the relationship between "mere exposure" and attitude enhancement is well established in the adult domain, there has been little similar work with children. This article examines whether toddlers' visual attention toward pictures of foods can be enhanced by repeated visual exposure to pictures of foods in a parent-administered picture book. We describe three studies that explored the number and nature of exposures required to elicit positive visual preferences for stimuli and the extent to which induced preferences generalize to other similar items. Results show that positive preferences for stimuli are easily and reliably induced in children and, importantly, that this effect of exposure is not restricted to the exposed stimulus per se but also applies to new representations of the exposed item.

Spatial and temporal relations in conditioned reinforcement and observing behavior.

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Bowe, C A; Dinsmoor, J A

1983-03-01

In Experiment 1, depressing one perch produced stimuli indicating which of two keys, if pecked, could produce food (spatial information) and depressing the other perch produced stimuli indicating whether a variable-interval or an extinction schedule was operating (temporal information). The pigeons increased the time they spent depressing the perch that produced the temporal information but did not increase the time they spent depressing the perch that produced the spatial information. In Experiment 2, pigeons that were allowed to produce combined spatial and temporal information did not acquire the perch pressing any faster or maintain it at a higher level than pigeons allowed to produce only temporal information. Later, when perching produced only spatial information, the time spent depressing the perch eventually declined. The results are not those implied by the statement that information concerning biologically important events is reinforcing but are consistent with an interpretation in terms of the acquisition of reinforcing properties by a stimulus associated with a higher density of primary reinforcement.

Muscular reflexes elicited by electrical stimulation of the anterior cruciate ligament in humans

DEFF Research Database (Denmark)

Dyhre-Poulsen, P; Krogsgaard, M R

2000-01-01

no sign of ACL disease, thin wire electrodes were inserted into the proximal and mid parts of the ACL. Postoperatively, the sensory nerve fibers inside the ACL were stimulated electrically while motor activity in the knee muscles was recorded using electromyography. In seven of the eight patients......, a muscular contraction of the semitendinosus muscle could be elicited with stimulus trains consisting of at least two stimuli. The latency was 95 +/- 35 ms. Stimulation during isometric contraction of either extensor or flexor muscles elicited a short, complete inhibition of the muscle activity...

Skin-transmitted pathogens and the heebie jeebies: evidence for a subclass of disgust stimuli that evoke a qualitatively unique emotional response.

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Blake, Khandis R; Yih, Jennifer; Zhao, Kun; Sung, Billy; Harmon-Jones, Cindy

2017-09-01

Skin-transmitted pathogens have threatened humans since ancient times. We investigated whether skin-transmitted pathogens were a subclass of disgust stimuli that evoked an emotional response that was related to, but distinct from, disgust and fear. We labelled this response "the heebie jeebies". In Study 1, coding of 76 participants' experiences of disgust, fear, and the heebie jeebies showed that the heebie jeebies was elicited by unique stimuli which produced skin-crawling sensations and an urge to protect the skin. In Experiment 2,350 participants' responses to skin-transmitted pathogen, fear-inducing, and disgust-inducing vignettes showed that the vignettes elicited sensations and urges which loaded onto heebie jeebies, fear, and disgust factors, respectively. Experiment 3 largely replicated findings from Experiment 2 using video stimuli (178 participants). Results are consistent with the notion that skin-transmitted pathogens are a subclass of disgust stimuli which motivate behaviours that are functionally consistent with disgust yet qualitatively distinct.

Anagrus breviphragma Soyka Short Distance Search Stimuli

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Elisabetta Chiappini

2015-01-01

Full Text Available Anagrus breviphragma Soyka (Hymenoptera: Mymaridae successfully parasitises eggs of Cicadella viridis (L. (Homoptera: Cicadellidae, embedded in vegetal tissues, suggesting the idea of possible chemical and physical cues, revealing the eggs presence. In this research, three treatments were considered in order to establish which types of cue are involved: eggs extracted from leaf, used as a control, eggs extracted from leaf and cleaned in water and ethanol, used to evaluate the presence of chemicals soluble in polar solvents, and eggs extracted from leaf and covered with Parafilm (M, used to avoid physical stimuli due to the bump on the leaf surface. The results show that eggs covered with Parafilm present a higher number of parasitised eggs and a lower probing starting time with respect to eggs washed with polar solvents or eggs extracted and untreated, both when the treatments were singly tested or when offered in sequence, independently of the treatment position. These results suggest that the exploited stimuli are not physical due to the bump but chemicals that can spread in the Parafilm, circulating the signal on the whole surface, and that the stimuli that elicit probing and oviposition are not subjected to learning.

Alleged Approach-Avoidance Conflict for Food Stimuli in Binge Eating Disorder.

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Elisabeth J Leehr

Full Text Available Food stimuli are omnipresent and naturally primary reinforcing stimuli. One explanation for the intake of high amounts of food in binge eating disorder (BED is a deviant valuation process. Valuation of food stimuli is supposed to influence approach or avoidance behaviour towards food. Focusing on self-reported and indirect (facial electromyography valuation process, motivational aspects in the processing of food stimuli were investigated.We compared an overweight sample with BED (BED+ with an overweight sample without BED (BED- and with normal weight controls (NWC regarding their self-reported and indirect (via facial electromyography valuation of food versus non-food stimuli.Regarding the self-reported valuation, the BED+ sample showed a significantly stronger food-bias compared to the BED- sample, as food stimuli were rated as significantly more positive than the non-food stimuli in the BED+ sample. This self-reported valuation pattern could not be displayed in the indirect valuation. Food stimuli evoked negative indirect valuation in all groups. The BED+ sample showed the plainest approach-avoidance conflict marked by a diverging self-reported (positive and indirect (negative valuation of food stimuli.BED+ showed a deviant self-reported valuation of food as compared to BED-. The valuation process of the BED+ sample seems to be characterized by a motivational ambivalence. This ambivalence should be subject of further studies and may be of potential use for therapeutic interventions.

Reward-associated stimuli capture the eyes in spite of strategic attentional set

NARCIS (Netherlands)

Hickey, C.M.; van Zoest, W.

2013-01-01

Theories of reinforcement learning have proposed that the association of reward to visual stimuli may cause these objects to become fundamentally salient and thus attention-drawing. A number of recent studies have investigated the oculomotor correlates of this reward-priming effect, but there is

Stress Enables Reinforcement-Elicited Serotonergic Consolidation of Fear Memory.

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Baratta, Michael V; Kodandaramaiah, Suhasa B; Monahan, Patrick E; Yao, Junmei; Weber, Michael D; Lin, Pei-Ann; Gisabella, Barbara; Petrossian, Natalie; Amat, Jose; Kim, Kyungman; Yang, Aimei; Forest, Craig R; Boyden, Edward S; Goosens, Ki A

2016-05-15

Prior exposure to stress is a risk factor for developing posttraumatic stress disorder (PTSD) in response to trauma, yet the mechanisms by which this occurs are unclear. Using a rodent model of stress-based susceptibility to PTSD, we investigated the role of serotonin in this phenomenon. Adult mice were exposed to repeated immobilization stress or handling, and the role of serotonin in subsequent fear learning was assessed using pharmacologic manipulation and western blot detection of serotonin receptors, measurements of serotonin, high-speed optogenetic silencing, and behavior. Both dorsal raphe serotonergic activity during aversive reinforcement and amygdala serotonin 2C receptor (5-HT2CR) activity during memory consolidation were necessary for stress enhancement of fear memory, but neither process affected fear memory in unstressed mice. Additionally, prior stress increased amygdala sensitivity to serotonin by promoting surface expression of 5-HT2CR without affecting tissue levels of serotonin in the amygdala. We also showed that the serotonin that drives stress enhancement of associative cued fear memory can arise from paired or unpaired footshock, an effect not predicted by theoretical models of associative learning. Stress bolsters the consequences of aversive reinforcement, not by simply enhancing the neurobiological signals used to encode fear in unstressed animals, but rather by engaging distinct mechanistic pathways. These results reveal that predictions from classical associative learning models do not always hold for stressed animals and suggest that 5-HT2CR blockade may represent a promising therapeutic target for psychiatric disorders characterized by excessive fear responses such as that observed in PTSD. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Processing of prosodic changes in natural speech stimuli in school-age children.

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Lindström, R; Lepistö, T; Makkonen, T; Kujala, T

2012-12-01

Speech prosody conveys information about important aspects of communication: the meaning of the sentence and the emotional state or intention of the speaker. The present study addressed processing of emotional prosodic changes in natural speech stimuli in school-age children (mean age 10 years) by recording the electroencephalogram, facial electromyography, and behavioral responses. The stimulus was a semantically neutral Finnish word uttered with four different emotional connotations: neutral, commanding, sad, and scornful. In the behavioral sound-discrimination task the reaction times were fastest for the commanding stimulus and longest for the scornful stimulus, and faster for the neutral than for the sad stimulus. EEG and EMG responses were measured during non-attentive oddball paradigm. Prosodic changes elicited a negative-going, fronto-centrally distributed neural response peaking at about 500 ms from the onset of the stimulus, followed by a fronto-central positive deflection, peaking at about 740 ms. For the commanding stimulus also a rapid negative deflection peaking at about 290 ms from stimulus onset was elicited. No reliable stimulus type specific rapid facial reactions were found. The results show that prosodic changes in natural speech stimuli activate pre-attentive neural change-detection mechanisms in school-age children. However, the results do not support the suggestion of automaticity of emotion specific facial muscle responses to non-attended emotional speech stimuli in children. Copyright © 2012 Elsevier B.V. All rights reserved.

Abnormal decision-making in generalized anxiety disorder: Aversion of risk or stimulus-reinforcement impairment?

OpenAIRE

Teng, Cindy; Otero, Marcela; Geraci, Marilla; Blair, R.J.R.; Pine, Daniel S.; Grillon, Christian; Blair, Karina S.

2016-01-01

There is preliminary data indicating that patients with generalized anxiety disorder (GAD) show impairment on decision-making tasks requiring the appropriate representation of reinforcement value. The current study aimed to extend this literature using the passive avoidance (PA) learning task, where the participant has to learn to respond to stimuli that engender reward and avoid responding to stimuli that engender punishment. Six stimuli engendering reward and six engendering punishment are ...

Seeing music: The perception of melodic 'ups and downs' modulates the spatial processing of visual stimuli.

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Romero-Rivas, Carlos; Vera-Constán, Fátima; Rodríguez-Cuadrado, Sara; Puigcerver, Laura; Fernández-Prieto, Irune; Navarra, Jordi

2018-05-10

Musical melodies have "peaks" and "valleys". Although the vertical component of pitch and music is well-known, the mechanisms underlying its mental representation still remain elusive. We show evidence regarding the importance of previous experience with melodies for crossmodal interactions to emerge. The impact of these crossmodal interactions on other perceptual and attentional processes was also studied. Melodies including two tones with different frequency (e.g., E4 and D3) were repeatedly presented during the study. These melodies could either generate strong predictions (e.g., E4-D3-E4-D3-E4-[D3]) or not (e.g., E4-D3-E4-E4-D3-[?]). After the presentation of each melody, the participants had to judge the colour of a visual stimulus that appeared in a position that was, according to the traditional vertical connotations of pitch, either congruent (e.g., high-low-high-low-[up]), incongruent (high-low-high-low-[down]) or unpredicted with respect to the melody. Behavioural and electroencephalographic responses to the visual stimuli were obtained. Congruent visual stimuli elicited faster responses at the end of the experiment than at the beginning. Additionally, incongruent visual stimuli that broke the spatial prediction generated by the melody elicited larger P3b amplitudes (reflecting 'surprise' responses). Our results suggest that the passive (but repeated) exposure to melodies elicits spatial predictions that modulate the processing of other sensory events. Copyright © 2018 Elsevier Ltd. All rights reserved.

Were Increased Closed Seclusions the Result of a Reinforcer-Abolishing Effect?

OpenAIRE

Poling, Alan

2013-01-01

In recent years, the motivating operation (MO) concept and the terms associated with it, including “reinforcer-abolishing effect” (Laraway, Snycerski, Michael, & Poling, 2003), have been widely used in the behavior-analytic literature (Laraway, Snycerski, Olson, Becker, & Poling, in press) and elsewhere (Lotfizadeh, Edwards, & Poling, 2013). MOs are changes in the environment that alter the reinforcing effectiveness of designated classes of stimuli, such as food or water.

Were Increased Closed Seclusions the Result of a Reinforcer-Abolishing Effect?

Science.gov (United States)

Poling, Alan

2013-01-01

In recent years, the motivating operation (MO) concept and the terms associated with it, including "reinforcer-abolishing effect" (Laraway, Snycerski, Michael, & Poling, 2003), have been widely used in the behavior-analytic literature (Laraway, Snycerski, Olson, Becker, & Poling, in press) and elsewhere (Lotfizadeh, Edwards, & Poling, 2013). MOs are changes in the environment that alter the reinforcing effectiveness of designated classes of stimuli, such as food or water.

Distress intolerance moderation of motivated attention to cannabis and negative stimuli after induced stress among cannabis users: an ERP study.

Science.gov (United States)

Macatee, Richard J; Okey, Sarah A; Albanese, Brian J; Schmidt, Norman B; Cougle, Jesse R

2018-05-07

Prevalence of cannabis use is increasing, but many regular users do not develop cannabis use disorder (CUD); thus, CUD risk identification among current users is vital for targeted intervention development. Existing data suggest that high distress intolerance (DI), an individual difference reflective of the ability to tolerate negative affect, may be linked to CUD, but no studies have tested possible neurophysiological mechanisms. Increased motivated attentional processing of cannabis and negative emotional stimuli as indexed by neurophysiology [i.e. the late positive potential (LPP)], particularly during acute stress, may contribute to CUD among high DI users. Frequent cannabis users with high (n = 61) and low DI (n = 44) viewed cannabis, negative, and matched neutral images during electroencephalography (EEG) recording before and after a laboratory stressor. Cannabis cue-elicited modulation of the 1000- to 3000-milliseconds LPP was larger in high DI users at post-stressor only, although the effect was only robust in the 1000- to 2000-milliseconds window. Further, modulation magnitude in the high DI group covaried with stress-relief craving and some CUD indices in the 400- to 1000-milliseconds and 1000- to 3000-milliseconds windows, respectively. No significant effects of DI on negative stimuli-elicited LPP modulation were found, although inverse associations with some CUD indices were observed. Finally, exploratory analyses revealed some evidence for DI moderation of the relation between subjective stressor reactivity and negative stimuli-elicited LPP modulation such that greater stressor reactivity was associated with blunted versus enhanced modulation in the high and low DI groups, respectively. Negative and cannabis stimuli-elicited LPP modulation appear to index distinct, CUD-relevant neural processes in high DI cannabis users. © 2018 Society for the Study of Addiction.

Rats do not respond differently in the presence of stimuli signaling wheel-running reinforcers of different durations.

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Belke, Terry W

2007-05-01

Rats were exposed to a fixed interval 30 s schedule that produced opportunities to run of equal or unequal durations to assess the effect of differences in duration on responding. Each duration was signaled by a different stimulus. Wheel-running reinforcer duration pairs were 30 s 30 s, 50 s 10 s, and 55 s 5 s. An analysis of median postreinforcement pause duration and mean local lever-pressing rates broken down by previous reinforcer duration and duration of signaled upcoming reinforcer showed that postreinforcement pause duration was affected by the duration of the previous reinforcer but not by the stimulus signaling the duration of the upcoming reinforcer. Local lever-pressing rates were not affected by either previous or upcoming reinforcer duration. In general, the results are consistent with indifference between these durations obtained using a concurrent choice procedure.

Neurochemical responses to chromatic and achromatic stimuli in the human visual cortex.

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Bednařík, Petr; Tkáč, Ivan; Giove, Federico; Eberly, Lynn E; Deelchand, Dinesh K; Barreto, Felipe R; Mangia, Silvia

2018-02-01

In the present study, we aimed at determining the metabolic responses of the human visual cortex during the presentation of chromatic and achromatic stimuli, known to preferentially activate two separate clusters of neuronal populations (called "blobs" and "interblobs") with distinct sensitivity to color or luminance features. Since blobs and interblobs have different cytochrome-oxidase (COX) content and micro-vascularization level (i.e., different capacities for glucose oxidation), different functional metabolic responses during chromatic vs. achromatic stimuli may be expected. The stimuli were optimized to evoke a similar load of neuronal activation as measured by the bold oxygenation level dependent (BOLD) contrast. Metabolic responses were assessed using functional 1 H MRS at 7 T in 12 subjects. During both chromatic and achromatic stimuli, we observed the typical increases in glutamate and lactate concentration, and decreases in aspartate and glucose concentration, that are indicative of increased glucose oxidation. However, within the detection sensitivity limits, we did not observe any difference between metabolic responses elicited by chromatic and achromatic stimuli. We conclude that the higher energy demands of activated blobs and interblobs are supported by similar increases in oxidative metabolism despite the different capacities of these neuronal populations.

Elicitation Techniques: Getting People to Talk about Ideas They Don't Usually Talk About

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Barton, Keith C.

2015-01-01

Elicitation techniques are a category of research tasks that use visual, verbal, or written stimuli to encourage participants to talk about their ideas. These tasks are particularly useful for exploring topics that may be difficult to discuss in formal interviews, such as those that involve sensitive issues or rely on tacit knowledge. Elicitation…

Brain Processing of Visual Stimuli Representing Sexual Penetration versus Core and Animal-Reminder Disgust in Women with Lifelong Vaginismus

OpenAIRE

Borg, Charmaine; Georgiadis, Janniko R.; Renken, Remco J.; Spoelstra, Symen K.; Weijmar Schultz, Willibrord; de Jong, Peter J.

2014-01-01

It has been proposed that disgust evolved to protect humans from contamination. Through eliciting the overwhelming urge to withdraw from the disgusting stimuli, it would facilitate avoidance of contact with pathogens. The physical proximity implied in sexual intercourse provides ample opportunity for contamination and may thus set the stage for eliciting pathogen disgust. Building on this, it has been argued that the involuntary muscle contraction characteristic of vaginismus (i.e., inability...

Haloperidol differentially affects reinforcement and motivational processes in rats running an alley for intravenous heroin.

Science.gov (United States)

McFarland, K; Ettenberg, A

1995-12-01

The role of drug-paired environmental stimuli in opiate self-administration was investigated by exposing animals to discrete cues that were predictive of the availability or unavailability of heroin reinforcement. Rats were trained to traverse a straight arm runway for a reinforcement consisting of a single 0.1 mg/kg intravenous infusion of heroin delivered upon entrance to the goal box. On each trial, one of two discriminative olfactory stimuli (orange and almond) was used: one which signaled the availability of heroin in the goal box (S+), and one which signaled its absence (S-). The effect of dopamine (DA) receptor antagonism on reinforcement and motivational processes was investigated by pretreating subjects with 0.0, 0.15 or 0.30 mg/kg of the DA receptor antagonist drug, haloperidol. Haloperidol had no effect on operant runway performance (i.e. goal time) in any condition. However, 24 h later, on the first post-treatment trial, those haloperidol animals that received heroin in the goal box on the previous trial (i.e. the S+ condition) ran reliably more slowly than subjects that received vehicle on the previous S+ trial. These results suggest that haloperidol does not affect the motivational properties of stimuli which predict the availability of heroin, while it does diminish the reinforcing effects of actually receiving heroin.

Enhanced brain susceptibility to negative stimuli in adolescents: ERP evidences

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Jiajin eYuan

2015-04-01

Full Text Available Background: previous studies investigated neural substrates of emotional face processing in adolescents and its comparison with adults. As emotional faces elicit more of emotional expression recognition rather than direct emotional responding, it remains undetermined how adolescents are different from adults in brain susceptibility to emotionally stressful stimuli. Methods: Event-Related Potentials were recorded for highly negative (HN, moderately negative (MN and Neutral pictures in 20 adolescents and 20 adults while subjects performed a standard/deviant distinction task by pressing different keys, irrespective of the emotionality of deviant stimuli. Results: Adolescents exhibited more negative amplitudes for HN versus neutral pictures in N1 (100-150ms, P2 (130-190ms, N2 (210-290ms and P3 (360-440ms components. In addition, adolescents showed more negative amplitudes for MN compared to neutral pictures in N1, P2 and N2 components. By contrast, adults exhibited significant emotion effects for HN stimuli in N2 and P3 amplitudes but not in N1 and P2 amplitudes, and they did not exhibit a significant emotion effect for MN stimuli at all these components. In the 210-290ms time interval, the emotion effect for HN stimuli was significant across frontal and central regions in adolescents, while this emotion effect was noticeable only in the central region for adults. Conclusions: Adolescents are more emotionally sensitive to negative stimuli compared to adults, regardless of the emotional intensity of the stimuli, possibly due to the immature prefrontal control system over the limbic emotional inputs during adolescence. Keywords: Event-Related Potentials (ERPs; Adolescence; Emotion intensity; Negative pictures; Emotional Susceptibility

Audiovisual semantic interactions between linguistic and nonlinguistic stimuli: The time-courses and categorical specificity.

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Chen, Yi-Chuan; Spence, Charles

2018-04-30

We examined the time-courses and categorical specificity of the crossmodal semantic congruency effects elicited by naturalistic sounds and spoken words on the processing of visual pictures (Experiment 1) and printed words (Experiment 2). Auditory cues were presented at 7 different stimulus onset asynchronies (SOAs) with respect to the visual targets, and participants made speeded categorization judgments (living vs. nonliving). Three common effects were observed across 2 experiments: Both naturalistic sounds and spoken words induced a slowly emerging congruency effect when leading by 250 ms or more in the congruent compared with the incongruent condition, and a rapidly emerging inhibitory effect when leading by 250 ms or less in the incongruent condition as opposed to the noise condition. Only spoken words that did not match the visual targets elicited an additional inhibitory effect when leading by 100 ms or when presented simultaneously. Compared with nonlinguistic stimuli, the crossmodal congruency effects associated with linguistic stimuli occurred over a wider range of SOAs and occurred at a more specific level of the category hierarchy (i.e., the basic level) than was required by the task. A comprehensive framework is proposed to provide a dynamic view regarding how meaning is extracted during the processing of visual or auditory linguistic and nonlinguistic stimuli, therefore contributing to our understanding of multisensory semantic processing in humans. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Lateralized eye use towards video stimuli in bearded dragons (Pogona vitticeps

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Anna Frohnwieser

2017-08-01

Full Text Available Lateralized eye use is thought to increase brain efficiency, as the two hemispheres process different information perceived by the eyes. It has been observed in a wide variety of vertebrate species and, in general, information about conspecifics appears to elicit a left eye preference whilst information about prey elicits the opposite. In reptiles, this phenomenon has only been investigated using live conspecifics in agonistic contexts, and so it is not clear whether it can be found when using video stimuli. Here, bearded dragons (Pogona vitticeps were presented with videos of female conspecifics and prey that either moved or were stationary, along with a control video of an empty background. Females exhibited a left eye bias towards conspecifics but males did not; however, both sexes looked at conspecifics significantly longer than prey. Further, animals used their left eye significantly longer when viewing moving stimuli of both categories. These results suggest that, in lizards, lateralized eye use when viewing conspecifics may be controlled by sex, and strongly influenced by stimulus movement. This study, therefore, provides important insights into the role of lateralized processing in lizard perception, and sets the scene for future work investigating the role of sex on perception of conspecifics and the role of motion in lateralized eye use.

Stimulus-Elicited Connectivity Influences Resting-State Connectivity Years Later in Human Development: A Prospective Study.

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Gabard-Durnam, Laurel Joy; Gee, Dylan Grace; Goff, Bonnie; Flannery, Jessica; Telzer, Eva; Humphreys, Kathryn Leigh; Lumian, Daniel Stephen; Fareri, Dominic Stephen; Caldera, Christina; Tottenham, Nim

2016-04-27

Although the functional architecture of the brain is indexed by resting-state connectivity networks, little is currently known about the mechanisms through which these networks assemble into stable mature patterns. The current study posits and tests the long-term phasic molding hypothesis that resting-state networks are gradually shaped by recurring stimulus-elicited connectivity across development by examining how both stimulus-elicited and resting-state functional connections of the human brain emerge over development at the systems level. Using a sequential design following 4- to 18-year-olds over a 2 year period, we examined the predictive associations between stimulus-elicited and resting-state connectivity in amygdala-cortical circuitry as an exemplar case (given this network's protracted development across these ages). Age-related changes in amygdala functional connectivity converged on the same regions of medial prefrontal cortex (mPFC) and inferior frontal gyrus when elicited by emotional stimuli and when measured at rest. Consistent with the long-term phasic molding hypothesis, prospective analyses for both connections showed that the magnitude of an individual's stimulus-elicited connectivity unidirectionally predicted resting-state functional connectivity 2 years later. For the amygdala-mPFC connection, only stimulus-elicited connectivity during childhood and the transition to adolescence shaped future resting-state connectivity, consistent with a sensitive period ending with adolescence for the amygdala-mPFC circuit. Together, these findings suggest that resting-state functional architecture may arise from phasic patterns of functional connectivity elicited by environmental stimuli over the course of development on the order of years. A fundamental issue in understanding the ontogeny of brain function is how resting-state (intrinsic) functional networks emerge and relate to stimulus-elicited functional connectivity. Here, we posit and test the long

A film set for the elicitation of emotion in research: A comprehensive catalog derived from four decades of investigation.

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Gilman, T Lee; Shaheen, Razan; Nylocks, K Maria; Halachoff, Danielle; Chapman, Jessica; Flynn, Jessica J; Matt, Lindsey M; Coifman, Karin G

2017-12-01

Emotions are highly influential to many psychological processes. Indeed, research employing emotional stimuli is rapidly escalating across the field of psychology. However, challenges remain regarding discrete evocation of frequently co-elicited emotions such as amusement and happiness, or anger and disgust. Further, as much contemporary work in emotion employs college students, we sought to additionally evaluate the efficacy of film clips to discretely elicit these more challenging emotions in a young adult population using an online medium. The internet is an important tool for investigating responses to emotional stimuli, but validations of emotionally evocative film clips across laboratory and web-based settings are limited in the literature. An additional obstacle is identifying stimuli amidst the numerous film clip validation studies. During our investigation, we recognized the lack of a categorical database to facilitate rapid identification of useful film clips for individual researchers' unique investigations. Consequently, here we also sought to produce the first compilation of such stimuli into an accessible and comprehensive catalog. We based our catalog upon prior work as well as our own, and identified 24 articles and 295 film clips from four decades of research. We present information on the validation of these clips in addition to our own research validating six clips using online administration settings. The results of our search in the literature and our own study are presented in tables designed to facilitate and improve a selection of highly valid film stimuli for future research.

Hemispheric specialization in dogs for processing different acoustic stimuli.

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Marcello Siniscalchi

Full Text Available Considerable experimental evidence shows that functional cerebral asymmetries are widespread in animals. Activity of the right cerebral hemisphere has been associated with responses to novel stimuli and the expression of intense emotions, such as aggression, escape behaviour and fear. The left hemisphere uses learned patterns and responds to familiar stimuli. Although such lateralization has been studied mainly for visual responses, there is evidence in primates that auditory perception is lateralized and that vocal communication depends on differential processing by the hemispheres. The aim of the present work was to investigate whether dogs use different hemispheres to process different acoustic stimuli by presenting them with playbacks of a thunderstorm and their species-typical vocalizations. The results revealed that dogs usually process their species-typical vocalizations using the left hemisphere and the thunderstorm sounds using the right hemisphere. Nevertheless, conspecific vocalizations are not always processed by the left hemisphere, since the right hemisphere is used for processing vocalizations when they elicit intense emotion, including fear. These findings suggest that the specialisation of the left hemisphere for intraspecific communication is more ancient that previously thought, and so is specialisation of the right hemisphere for intense emotions.

The acute glucocorticoid stress response does not differentiate between rewarding and aversive social stimuli in rats

NARCIS (Netherlands)

Buwalda, Bauke; Scholte, Jan; de Boer, Sietse F.; Coppens, Caroline M.; Koolhaas, Jaap M.

The mere presence of elevated plasma levels of corticosterone is generally regarded as evidence of compromised well-being. However, environmental stimuli do not necessarily need to be of a noxious or adverse nature to elicit activation of the stress response systems. In the present study, the

Nicotine Acutely Enhances Reinforcement from Non-Drug Rewards in Humans

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Kenneth A. Perkins

2017-05-01

Full Text Available Preclinical research documents that, aside from the primary and secondary reinforcing effects of nicotine intake itself, nicotine also acutely enhances the reinforcing efficacy of non-drug reinforcers (“rewards”. Study of these effects in humans has largely been overlooked, but very recent findings suggest they may have clinical implications for more fully understanding the persistence of tobacco dependence. This overview first outlines the topic and notes some recent human studies indirectly addressing nicotine effects on related responses (e.g., subjective ratings, explaining why those findings do not directly confirm enhancement of behavioral reinforcement per se due to nicotine. Then, the methodology used in the subsequently presented studies is described, demonstrating how those studies specifically did demonstrate enhancement of reinforced responding for non-drug rewards. The main section focuses on the limited controlled research to date directly assessing nicotine’s acute reinforcement-enhancing effects in humans, particularly as it relates to reinforced behavioral responding for non-drug rewards in non-human animal models. After detailing those few existing human studies, we address potential consequences of these effects for dependence and tobacco cessation efforts and then suggest directions for future research. This research indicates that nicotine per se increases responding in humans that is reinforced by some rewards (auditory stimuli via music, visual stimuli via video, but perhaps not by others (e.g., money. These reinforcement-enhancing effects in smokers are not due to dependence or withdrawal relief and can be restored by a small amount of nicotine (similar to a smoking lapse, including from e-cigarettes, a non-tobacco nicotine product. Future clinical research should examine factors determining which types of rewards are (or are not enhanced by nicotine, consequences of the loss of these nicotine effects after quitting

Enhancing the Effects of Extinction on Attention-Maintained Behavior through Noncontingent Delivery of Attention or Stimuli Identified Via a Competing Stimulus Assessment

Science.gov (United States)

Fisher, Wayne W.; DeLeon, Iser G.; Rodriguez-Catter, Vanessa; Keeney, Kris M.

2004-01-01

Recent research has shown that the noncontingent delivery of competing stimuli can effectively reduce rates of destructive behavior maintained by social-positive reinforcement, even when the contingency for destructive behavior remains intact. It may be useful, therefore, to have a systematic means for predicting which reinforcers do and do not…

The processing of infrequently-presented low-intensity stimuli during natural sleep: An event-related potential study

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Alexandra Muller-Gass

2010-01-01

Full Text Available Event-related potentials (ERPs provide an exquisite means to measure the extent of processing of external stimuli during the sleep period. This study examines ERPs elicited by stimuli with physical characteristics akin to environmental noise encountered during sleep. Brief duration 40, 60 or 80 dB sound pressure level (SPL tones were presented either rapidly (on average every two seconds or slowly (on average every 10 seconds. The rates of presentation and intensity of the stimuli were similar to those observed in environmental studies of noise. ERPs were recorded from nine young adults during sleep and wakefulness. During wakefulness, the amplitude of an early negative ERP, N1, systematically increased as intensity level increased. A later positivity, the P3a, was apparent following the loudest 80 dB stimulus regardless of the rate of stimulus presentation; it was also apparent following the 60 dB stimulus, when stimuli were presented slowly. The appearance of the N1-P3a deflections suggests that operations of the central executive controlling ongoing cognitive activity was interrupted, forcing subjects to become aware of the obtrusive task-irrelevant stimuli. The auditory stimuli elicited very different ERP patterns during sleep. During non-rapid eye movement (NREM sleep, the ERP was characterized by an enhanced (relative to wakefulness early positivity, P2, followed by a very prominent negativity, the N350. Both deflections systematically varied in amplitude with stimulus intensity level; in addition, N350 was much larger when stimuli were presented at slow rates. The N350, a sleep-specific ERP, is thought to reflect the inhibition of processing of potentially sleep-disrupting stimulus input. During rapid eye movement (REM sleep, a small amplitude N1 was apparent in the ERP, but only for the loudest, 80 dB stimulus. A small (nonsignificant P3a-like deflection was also visible following the 80 dB stimulus, but only when stimuli were presented

The relationship between age and brain response to visual erotic stimuli in healthy heterosexual males.

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Seo, Y; Jeong, B; Kim, J-W; Choi, J

2010-01-01

The various changes of sexuality, including decreased sexual desire and erectile dysfunction, are also accompanied with aging. To understand the effect of aging on sexuality, we explored the relationship between age and the visual erotic stimulation-related brain response in sexually active male subjects. Twelve healthy, heterosexual male subjects (age 22-47 years) were recorded the functional magnetic resonance imaging (fMRI) signals of their brain activation elicited by passive viewing erotic (ERO), happy-faced (HA) couple, food and nature pictures. Mixed effect analysis and correlation analysis were performed to investigate the relationship between the age and the change of brain activity elicited by erotic stimuli. Our results showed age was positively correlated with the activation of right occipital fusiform gyrus and amygdala, and negatively correlated with the activation of right insula and inferior frontal gyrus. These findings suggest age might be related with functional decline in brain regions being involved in both interoceptive sensation and prefrontal modulation while it is related with the incremental activity of the brain region for early processing of visual emotional stimuli in sexually healthy men.

Brain processing of visual stimuli representing sexual penetration versus core and animal-reminder disgust in women with lifelong vaginismus.

Science.gov (United States)

Borg, Charmaine; Georgiadis, Janniko R; Renken, Remco J; Spoelstra, Symen K; Weijmar Schultz, Willibrord; de Jong, Peter J

2014-01-01

It has been proposed that disgust evolved to protect humans from contamination. Through eliciting the overwhelming urge to withdraw from the disgusting stimuli, it would facilitate avoidance of contact with pathogens. The physical proximity implied in sexual intercourse provides ample opportunity for contamination and may thus set the stage for eliciting pathogen disgust. Building on this, it has been argued that the involuntary muscle contraction characteristic of vaginismus (i.e., inability to have vaginal penetration) may be elicited by the prospect of penetration by potential contaminants. To further investigate this disgust-based interpretation of vaginismus (in DSM-5 classified as a Genito-Pelvic Pain/Penetration Disorder, GPPPD) we used functional magnetic resonance imaging (fMRI) to examine if women with vaginismus (n = 21) show relatively strong convergence in their brain responses towards sexual penetration- and disgust-related pictures compared to sexually asymptomatic women (n = 21) and women suffering from vulvar pain (dyspareunia/also classified as GPPPD in the DSM-5, n = 21). At the subjective level, both clinical groups rated penetration stimuli as more disgusting than asymptomatic women. However, the brain responses to penetration stimuli did not differ between groups. In addition, there was considerable conjoint brain activity in response to penetration and disgust pictures, which yield for both animal-reminder (e.g., mutilation) and core (e.g., rotten food) disgust domains. However, this overlap in brain activation was similar for all groups. A possible explanation for the lack of vaginismus-specific brain responses lies in the alleged female ambiguity (procreation/pleasure vs. contamination/disgust) toward penetration: generally in women a (default) disgust response tendency may prevail in the absence of sexual readiness. Accordingly, a critical next step would be to examine the processing of penetration stimuli following the

Brain processing of visual stimuli representing sexual penetration versus core and animal-reminder disgust in women with lifelong vaginismus.

Directory of Open Access Journals (Sweden)

Charmaine Borg

Full Text Available It has been proposed that disgust evolved to protect humans from contamination. Through eliciting the overwhelming urge to withdraw from the disgusting stimuli, it would facilitate avoidance of contact with pathogens. The physical proximity implied in sexual intercourse provides ample opportunity for contamination and may thus set the stage for eliciting pathogen disgust. Building on this, it has been argued that the involuntary muscle contraction characteristic of vaginismus (i.e., inability to have vaginal penetration may be elicited by the prospect of penetration by potential contaminants. To further investigate this disgust-based interpretation of vaginismus (in DSM-5 classified as a Genito-Pelvic Pain/Penetration Disorder, GPPPD we used functional magnetic resonance imaging (fMRI to examine if women with vaginismus (n = 21 show relatively strong convergence in their brain responses towards sexual penetration- and disgust-related pictures compared to sexually asymptomatic women (n = 21 and women suffering from vulvar pain (dyspareunia/also classified as GPPPD in the DSM-5, n = 21. At the subjective level, both clinical groups rated penetration stimuli as more disgusting than asymptomatic women. However, the brain responses to penetration stimuli did not differ between groups. In addition, there was considerable conjoint brain activity in response to penetration and disgust pictures, which yield for both animal-reminder (e.g., mutilation and core (e.g., rotten food disgust domains. However, this overlap in brain activation was similar for all groups. A possible explanation for the lack of vaginismus-specific brain responses lies in the alleged female ambiguity (procreation/pleasure vs. contamination/disgust toward penetration: generally in women a (default disgust response tendency may prevail in the absence of sexual readiness. Accordingly, a critical next step would be to examine the processing of penetration stimuli following

Brain Processing of Visual Stimuli Representing Sexual Penetration versus Core and Animal-Reminder Disgust in Women with Lifelong Vaginismus

Science.gov (United States)

Borg, Charmaine; Georgiadis, Janniko R.; Renken, Remco J.; Spoelstra, Symen K.; Weijmar Schultz, Willibrord; de Jong, Peter J.

2014-01-01

It has been proposed that disgust evolved to protect humans from contamination. Through eliciting the overwhelming urge to withdraw from the disgusting stimuli, it would facilitate avoidance of contact with pathogens. The physical proximity implied in sexual intercourse provides ample opportunity for contamination and may thus set the stage for eliciting pathogen disgust. Building on this, it has been argued that the involuntary muscle contraction characteristic of vaginismus (i.e., inability to have vaginal penetration) may be elicited by the prospect of penetration by potential contaminants. To further investigate this disgust-based interpretation of vaginismus (in DSM-5 classified as a Genito-Pelvic Pain/Penetration Disorder, GPPPD) we used functional magnetic resonance imaging (fMRI) to examine if women with vaginismus (n = 21) show relatively strong convergence in their brain responses towards sexual penetration- and disgust-related pictures compared to sexually asymptomatic women (n = 21) and women suffering from vulvar pain (dyspareunia/also classified as GPPPD in the DSM-5, n = 21). At the subjective level, both clinical groups rated penetration stimuli as more disgusting than asymptomatic women. However, the brain responses to penetration stimuli did not differ between groups. In addition, there was considerable conjoint brain activity in response to penetration and disgust pictures, which yield for both animal-reminder (e.g., mutilation) and core (e.g., rotten food) disgust domains. However, this overlap in brain activation was similar for all groups. A possible explanation for the lack of vaginismus-specific brain responses lies in the alleged female ambiguity (procreation/pleasure vs. contamination/disgust) toward penetration: generally in women a (default) disgust response tendency may prevail in the absence of sexual readiness. Accordingly, a critical next step would be to examine the processing of penetration stimuli following the

Brain Processing of Visual Stimuli Representing Sexual Penetration versus Core and Animal-Reminder Disgust in Women with Lifelong Vaginismus

NARCIS (Netherlands)

Borg, Charmaine; Georgiadis, Janniko R.; Renken, Remco J.; Spoelstra, Symen K.; Weijmar Schultz, Willibrordus; de Jong, Peter

2014-01-01

It has been proposed that disgust evolved to protect humans from contamination. Through eliciting the overwhelming urge to withdraw from the disgusting stimuli, it would facilitate avoidance of contact with pathogens. The physical proximity implied in sexual intercourse provides ample opportunity

Stimuli eliciting sexual arousal in males who offend adult women: an experimental study.

Science.gov (United States)

Kolárský, A; Madlafousek, J; Novotná, V

1978-03-01

The sexually arousing effects of short film scenes showing a naked actress's seductive behavior were phalloplethysmographically measured in 14 sexual deviates. These were males who had offended adult women, predominantly exhibitionists. Controls were 14 normal men. Deviates responded positively to the scenes and differentiated strong and weak seduction scenes similarly to normals. Consequently, the question arises of why deviates avoid their victim's erotic cooperation and why they do not offend their regular sexual partners. Post hoc analysis of five scenes which elicited a strikingly higher response in deviates than in normals suggested that these scenes contained reduced seductive behavior but unrestrained presentation of the genitals. This finding further encourages the laboratory study of stimulus conditions for abnormal sexual arousal which occurs during the sexual offense.

Neural responses to smoking stimuli are influenced by smokers' attitudes towards their own smoking behaviour.

Science.gov (United States)

Stippekohl, Bastian; Winkler, Markus H; Walter, Bertram; Kagerer, Sabine; Mucha, Ronald F; Pauli, Paul; Vaitl, Dieter; Stark, Rudolf

2012-01-01

An important feature of addiction is the high drug craving that may promote the continuation of consumption. Environmental stimuli classically conditioned to drug-intake have a strong motivational power for addicts and can elicit craving. However, addicts differ in the attitudes towards their own consumption behavior: some are content with drug taking (consonant users) whereas others are discontent (dissonant users). Such differences may be important for clinical practice because the experience of dissonance might enhance the likelihood to consider treatment. This fMRI study investigated in smokers whether these different attitudes influence subjective and neural responses to smoking stimuli. Based on self-characterization, smokers were divided into consonant and dissonant smokers. These two groups were presented smoking stimuli and neutral stimuli. Former studies have suggested differences in the impact of smoking stimuli depending on the temporal stage of the smoking ritual they are associated with. Therefore, we used stimuli associated with the beginning (BEGIN-smoking-stimuli) and stimuli associated with the terminal stage (END-smoking-stimuli) of the smoking ritual as distinct stimulus categories. Stimulus ratings did not differ between both groups. Brain data showed that BEGIN-smoking-stimuli led to enhanced mesolimbic responses (amygdala, hippocampus, insula) in dissonant compared to consonant smokers. In response to END-smoking-stimuli, dissonant smokers showed reduced mesocortical responses (orbitofrontal cortex, subcallosal cortex) compared to consonant smokers. These results suggest that smoking stimuli with a high incentive value (BEGIN-smoking-stimuli) are more appetitive for dissonant than consonant smokers at least on the neural level. To the contrary, smoking stimuli with low incentive value (END-smoking-stimuli) seem to be less appetitive for dissonant smokers than consonant smokers. These differences might be one reason why dissonant smokers

Neural responses to smoking stimuli are influenced by smokers' attitudes towards their own smoking behaviour.

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Bastian Stippekohl

Full Text Available An important feature of addiction is the high drug craving that may promote the continuation of consumption. Environmental stimuli classically conditioned to drug-intake have a strong motivational power for addicts and can elicit craving. However, addicts differ in the attitudes towards their own consumption behavior: some are content with drug taking (consonant users whereas others are discontent (dissonant users. Such differences may be important for clinical practice because the experience of dissonance might enhance the likelihood to consider treatment. This fMRI study investigated in smokers whether these different attitudes influence subjective and neural responses to smoking stimuli. Based on self-characterization, smokers were divided into consonant and dissonant smokers. These two groups were presented smoking stimuli and neutral stimuli. Former studies have suggested differences in the impact of smoking stimuli depending on the temporal stage of the smoking ritual they are associated with. Therefore, we used stimuli associated with the beginning (BEGIN-smoking-stimuli and stimuli associated with the terminal stage (END-smoking-stimuli of the smoking ritual as distinct stimulus categories. Stimulus ratings did not differ between both groups. Brain data showed that BEGIN-smoking-stimuli led to enhanced mesolimbic responses (amygdala, hippocampus, insula in dissonant compared to consonant smokers. In response to END-smoking-stimuli, dissonant smokers showed reduced mesocortical responses (orbitofrontal cortex, subcallosal cortex compared to consonant smokers. These results suggest that smoking stimuli with a high incentive value (BEGIN-smoking-stimuli are more appetitive for dissonant than consonant smokers at least on the neural level. To the contrary, smoking stimuli with low incentive value (END-smoking-stimuli seem to be less appetitive for dissonant smokers than consonant smokers. These differences might be one reason why dissonant

Procrastination in the pigeon: Can conditioned reinforcement increase the likelihood of human procrastination?

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Zentall, Thomas R; Case, Jacob P; Andrews, Danielle M

2017-11-29

Procrastination is the tendency to put off initiation or completion of a task. Although people are typically known to procrastinate, recent research suggests that they sometimes "pre-crastinate" by initiating a task sooner than they need to (Rosenbaum et al. in Psychological Science, 25(7), 1487-1496, 2014). A similar finding of precrastination was reported by Wasserman and Brzykcy (Psychonomic Bulletin & Review, 22, 1130-1134, 2015) with pigeons using a somewhat different procedure. In the present experiment, we used a procedure with pigeons that was more similar to the procedure used by Rosenbaum et al. Pigeons were given a choice between two sequences of events (concurrent chains). Choice of the procrastination chain resulted in color A, which 15-s later would change to color B and 5-s later resulted in reinforcement. Choice of the precrastination chain resulted in color C, which 5-s later would change to color D and 15-s later resulted in reinforcement. Thus, both chains led to reinforcement after 20 s. Results indicated that the pigeons procrastinated. That is, they preferred the 15-5 chain over the 5-15 chain. The results are consistent with Fantino's (Journal of the Experimental Analysis of Behavior, 12, 723-730, 1969) delay reduction theory, which posits that stimuli that signal a reduction in the delay to reinforcement, such as the 5-s stimulus that occurred immediately prior to reinforcement, serve as strong conditioned reinforcers and should be preferred. In support of this theory, the pigeons pecked most at the 5-s stimulus that led immediately to reinforcement, indicating that it had become a strong conditioned reinforcer. The results suggest that delay reduction theory, a theory that emphasizes the attraction to stimuli that predict reinforcement with a short delay, also may contribute to human procrastination behavior because when task completion comes just before the deadline, it may become a stronger conditioned reinforcer than if task completion

Cue-elicited food seeking is eliminated with aversive outcomes following outcome devaluation.

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Eder, Andreas B; Dignath, David

2016-01-01

In outcome-selective Pavlovian-to-instrumental transfer (PIT), stimuli that are predictive of specific outcomes prime instrumental responses that are associated with these outcomes. Previous human studies yielded mixed evidence in respect to whether the PIT effect is affected by a posttraining devaluation of an outcome, with the PIT effect being preserved after a devaluation of a primary reinforcer (food, drugs) but not following the devaluation of a secondary reinforcer (money). The present research examined whether outcome-selective transfer is eliminated when the devaluation of a primary (liquid) reinforcer is strong and aversive. Experiment 1 confirmed these expectations following a devaluation with bad tasting Tween 20. However, outcome-selective transfer was still observed when the earned (devalued) outcome was not consumed immediately after each test (Experiment 2). These results suggest that the capacity of a Pavlovian cue to motivate a specific response is affected by the incentive value of the shared outcome only when the devaluation yields an aversive outcome that is consumed immediately.

Eliciting conditioned taste aversion in lizards: Live toxic prey are more effective than scent and taste cues alone.

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Ward-Fear, Georgia; Thomas, Jai; Webb, Jonathan K; Pearson, David J; Shine, Richard

2017-03-01

Conditioned taste aversion (CTA) is an adaptive learning mechanism whereby a consumer associates the taste of a certain food with symptoms caused by a toxic substance, and thereafter avoids eating that type of food. Recently, wildlife researchers have employed CTA to discourage native fauna from ingesting toxic cane toads (Rhinella marina), a species that is invading tropical Australia. In this paper, we compare the results of 2 sets of CTA trials on large varanid lizards ("goannas," Varanus panoptes). One set of trials (described in this paper) exposed recently-captured lizards to sausages made from cane toad flesh, laced with a nausea-inducing chemical (lithium chloride) to reinforce the aversion response. The other trials (in a recently-published paper, reviewed herein) exposed free-ranging lizards to live juvenile cane toads. The effectiveness of the training was judged by how long a lizard survived in the wild before it was killed (fatally poisoned) by a cane toad. Both stimuli elicited rapid aversion to live toads, but the CTA response did not enhance survival rates of the sausage-trained goannas after they were released into the wild. In contrast, the goannas exposed to live juvenile toads exhibited higher long-term survival rates than did untrained conspecifics. Our results suggest that although it is relatively easy to elicit short-term aversion to toad cues in goannas, a biologically realistic stimulus (live toads, encountered by free-ranging predators) is most effective at buffering these reptiles from the impact of invasive toxic prey. © 2016 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

Effects of auditory stimuli in the horizontal plane on audiovisual integration: an event-related potential study.

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Yang, Weiping; Li, Qi; Ochi, Tatsuya; Yang, Jingjing; Gao, Yulin; Tang, Xiaoyu; Takahashi, Satoshi; Wu, Jinglong

2013-01-01

This article aims to investigate whether auditory stimuli in the horizontal plane, particularly originating from behind the participant, affect audiovisual integration by using behavioral and event-related potential (ERP) measurements. In this study, visual stimuli were presented directly in front of the participants, auditory stimuli were presented at one location in an equidistant horizontal plane at the front (0°, the fixation point), right (90°), back (180°), or left (270°) of the participants, and audiovisual stimuli that include both visual stimuli and auditory stimuli originating from one of the four locations were simultaneously presented. These stimuli were presented randomly with equal probability; during this time, participants were asked to attend to the visual stimulus and respond promptly only to visual target stimuli (a unimodal visual target stimulus and the visual target of the audiovisual stimulus). A significant facilitation of reaction times and hit rates was obtained following audiovisual stimulation, irrespective of whether the auditory stimuli were presented in the front or back of the participant. However, no significant interactions were found between visual stimuli and auditory stimuli from the right or left. Two main ERP components related to audiovisual integration were found: first, auditory stimuli from the front location produced an ERP reaction over the right temporal area and right occipital area at approximately 160-200 milliseconds; second, auditory stimuli from the back produced a reaction over the parietal and occipital areas at approximately 360-400 milliseconds. Our results confirmed that audiovisual integration was also elicited, even though auditory stimuli were presented behind the participant, but no integration occurred when auditory stimuli were presented in the right or left spaces, suggesting that the human brain might be particularly sensitive to information received from behind than both sides.

Responding for sucrose and wheel-running reinforcement: effect of D-amphetamine.

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Belke, T W; Oldford, A C; Forgie, M Y; Beye, J A

2005-07-01

The present study assessed the effect of D-amphetamine on responding maintained by wheel-running and sucrose reinforcement. Six male albino Wistar rats were placed in running wheels and exposed to a fixed-interval 30-s schedule that produced either a drop of 5% sucrose solution or the opportunity to run for 15 s as reinforcing consequences for lever pressing. Each reinforcer type was signaled by a different stimulus. Doses of 0.25, 0.5, 1.0, 1.5, and 3.0 mg/kg D-amphetamine were administered by i.p. injection 20 min prior to a session. As the dose increased, index of curvature values decreased toward zero and rate-dependency plots revealed increases in lower rates early in the interval and decreases in higher rates toward the end of the interval. Effects were similar in the presence of both stimuli. However, an analysis of post-reinforcement pauses and local response rates broken down by transitions revealed a differential effect. As the dose increased, local response rates following a wheel-running reinforcer were affected more than those following a sucrose reinforcer.

Evaluation of Absolute and Relative Reinforcer Value Using Progressive-Ratio Schedules

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Francisco, Monica T.; Borrero, John C.; Sy, Jolene R.

2008-01-01

We evaluated behavior exhibited by individuals with developmental disabilities using progressive-ratio (PR) schedules. High- and low-preference stimuli were determined based on the results of a paired-stimulus preference assessment and were evaluated in subsequent reinforcer and PR assessments using concurrent and single schedules of presentation.…

Evaluation of a Multiple-Stimulus Presentation Format for Assessing Reinforcer Preferences.

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DeLeon, Iser G.; Iwata, Brian A.

1996-01-01

A study of seven adults with profound developmental disabilities compared methods for presenting stimuli during reinforcer-preference assessments. It found that a multiple-stimulus format in which selections were made without replacement may share the advantages of a paired-stimulus format and a multiple-stimulus format with replacement, while…

Behavioral sensitivity to changing reinforcement contingencies in attention-deficit hyperactivity disorder.

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Alsop, Brent; Furukawa, Emi; Sowerby, Paula; Jensen, Stephanie; Moffat, Cara; Tripp, Gail

2016-08-01

Altered sensitivity to positive reinforcement has been hypothesized to contribute to the symptoms of attention-deficit hyperactivity disorder (ADHD). In this study, we evaluated the ability of children with and without ADHD to adapt their behavior to changing reinforcer availability. Of one hundred sixty-seven children, 97 diagnosed with ADHD completed a signal-detection task in which correct discriminations between two stimuli were associated with different frequencies of reinforcement. The response alternative associated with the higher rate of reinforcement switched twice during the task without warning. For a subset of participants, this was followed by trials for which no reinforcement was delivered, irrespective of performance. Children in both groups developed an initial bias toward the more frequently reinforced response alternative. When the response alternative associated with the higher rate of reinforcement switched, the children's response allocation (bias) followed suit, but this effect was significantly smaller for children with ADHD. When reinforcement was discontinued, only children in the control group modified their response pattern. Children with ADHD adjust their behavioral responses to changing reinforcer availability less than typically developing children, when reinforcement is intermittent and the association between an action and its consequences is uncertain. This may explain the difficulty children with ADHD have adapting their behavior to new situations, with different reinforcement contingencies, in daily life. © 2016 Association for Child and Adolescent Mental Health.

Attention modulates the dorsal striatum response to love stimuli.

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Langeslag, Sandra J E; van der Veen, Frederik M; Röder, Christian H

2014-02-01

In previous functional magnetic resonance imaging (fMRI) studies concerning romantic love, several brain regions including the caudate and putamen have consistently been found to be more responsive to beloved-related than control stimuli. In those studies, infatuated individuals were typically instructed to passively view the stimuli or to think of the viewed person. In the current study, we examined how the instruction to attend to, or ignore the beloved modulates the response of these brain areas. Infatuated individuals performed an oddball task in which pictures of their beloved and friend served as targets and distractors. The dorsal striatum showed greater activation for the beloved than friend, but only when they were targets. The dorsal striatum actually tended to show less activation for the beloved than the friend when they were distractors. The longer the love and relationship duration, the smaller the response of the dorsal striatum to beloved-distractor stimuli was. We interpret our findings in terms of reinforcement learning. By virtue of using a cognitive task with a full factorial design, we show that the dorsal striatum is not activated by beloved-related information per se, but only by beloved-related information that is attended. Copyright © 2012 Wiley Periodicals, Inc.

The N170 component is sensitive to face-like stimuli: a study of Chinese Peking opera makeup.

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Liu, Tiantian; Mu, Shoukuan; He, Huamin; Zhang, Lingcong; Fan, Cong; Ren, Jie; Zhang, Mingming; He, Weiqi; Luo, Wenbo

2016-12-01

The N170 component is considered a neural marker of face-sensitive processing. In the present study, the face-sensitive N170 component of event-related potentials (ERPs) was investigated with a modified oddball paradigm using a natural face (the standard stimulus), human- and animal-like makeup stimuli, scrambled control images that mixed human- and animal-like makeup pieces, and a grey control image. Nineteen participants were instructed to respond within 1000 ms by pressing the ' F ' or ' J ' key in response to the standard or deviant stimuli, respectively. We simultaneously recorded ERPs, response accuracy, and reaction times. The behavioral results showed that the main effect of stimulus type was significant for reaction time, whereas there were no significant differences in response accuracies among stimulus types. In relation to the ERPs, N170 amplitudes elicited by human-like makeup stimuli, animal-like makeup stimuli, scrambled control images, and a grey control image progressively decreased. A right hemisphere advantage was observed in the N170 amplitudes for human-like makeup stimuli, animal-like makeup stimuli, and scrambled control images but not for grey control image. These results indicate that the N170 component is sensitive to face-like stimuli and reflect configural processing in face recognition.

Contextual influences on implicit evaluation: a test of additive versus contrastive effects of evaluative context stimuli in affective priming.

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Gawronski, Bertram; Deutsch, Roland; Seidel, Oliver

2005-09-01

Drawing on two alternative accounts of the affective priming effect (spreading activation vs. response interference), the present research investigated the underlying processes of how evaluative context stimuli influence implicit evaluations in the affective priming task. Employing two sequentially presented prime stimuli (rather than a single prime), two experiments showed that affective priming effects elicited by a given prime stimulus were more pronounced when this stimulus was preceded by a context prime of the opposite valence than when it was preceded by a context prime of the same valence. This effect consistently emerged for pictures (Experiment 1) and words (Experiment 2) as prime stimuli. These results suggest that the impact of evaluative context stimuli on implicit evaluations is mediated by contrast effects in the attention to evaluative information rather than by additive effects in the activation of evaluative information in associative memory.

Crosslinked ionic polysaccharides for stimuli-sensitive drug delivery.

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Alvarez-Lorenzo, Carmen; Blanco-Fernandez, Barbara; Puga, Ana M; Concheiro, Angel

2013-08-01

Polysaccharides are gaining increasing attention as components of stimuli-responsive drug delivery systems, particularly since they can be obtained in a well characterized and reproducible way from the natural sources. Ionic polysaccharides can be readily crosslinked to render hydrogel networks sensitive to a variety of internal and external variables, and thus suitable for switching drug release on-off through diverse mechanisms. Hybrids, composites and grafted polymers can reinforce the responsiveness and widen the range of stimuli to which polysaccharide-based systems can respond. This review analyzes the state of the art of crosslinked ionic polysaccharides as components of delivery systems that can regulate drug release as a function of changes in pH, ion nature and concentration, electric and magnetic field intensity, light wavelength, temperature, redox potential, and certain molecules (enzymes, illness markers, and so on). Examples of specific applications are provided. The information compiled demonstrates that crosslinked networks of ionic polysaccharides are suitable building blocks for developing advanced externally activated and feed-back modulated drug delivery systems. Copyright © 2013 Elsevier B.V. All rights reserved.

Motivational properties of reward associated stimuli - Conditioning studies with smoke and monetary reinforcement

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Winkler, Markus Heinrich

2015-01-01

Abstract Tobacco addiction is considered as a chronic relapsing disorder, characterized by compul-sive drug seeking and intake. Learning processes are stressed to account for the situational-specific expression of core features of the disorder, e.g., craving for drug, tolerance and ex-cessive consumption. According to incentive theories, smoke conditioned stimuli are hy-pothesized to be appetitive in nature, promoting craving, approach and consummatory be-havior. Commonly, smoking cues are...

Mid-adolescent neurocognitive development of ignoring and attending emotional stimuli

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Nora C. Vetter

2015-08-01

Full Text Available Appropriate reactions toward emotional stimuli depend on the distribution of prefrontal attentional resources. In mid-adolescence, prefrontal top-down control systems are less engaged, while subcortical bottom-up emotional systems are more engaged. We used functional magnetic resonance imaging to follow the neural development of attentional distribution, i.e. attending versus ignoring emotional stimuli, in adolescence. 144 healthy adolescents were studied longitudinally at age 14 and 16 while performing a perceptual discrimination task. Participants viewed two pairs of stimuli – one emotional, one abstract – and reported on one pair whether the items were the same or different, while ignoring the other pair. Hence, two experimental conditions were created: “attending emotion/ignoring abstract” and “ignoring emotion/attending abstract”. Emotional valence varied between negative, positive, and neutral. Across conditions, reaction times and error rates decreased and activation in the anterior cingulate and inferior frontal gyrus increased from age 14 to 16. In contrast, subcortical regions showed no developmental effect. Activation of the anterior insula increased across ages for attending positive and ignoring negative emotions. Results suggest an ongoing development of prefrontal top-down resources elicited by emotional attention from age 14 to 16 while activity of subcortical regions representing bottom-up processing remains stable.

Salient stimuli in advertising: the effect of contrast interval length and type on recall.

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Olsen, G Douglas

2002-09-01

Salient auditory stimuli (e.g., music or sound effects) are commonly used in advertising to elicit attention. However, issues related to the effectiveness of such stimuli are not well understood. This research examines the ability of a salient auditory stimulus, in the form of a contrast interval (CI), to enhance recall of message-related information. Researchers have argued that the effectiveness of the CI is a function of the temporal duration between the onset and offset of the change in the background stimulus and the nature of this stimulus. Three experiments investigate these propositions and indicate that recall is enhanced, providing the CI is 3 s or less. Information highlighted with silence is recalled better than information highlighted with music.

Chronic repeated exposure to weather-related stimuli elicits few symptoms of chronic stress in captive molting and non-molting European starlings (Sturnus vulgaris).

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de Bruijn, Robert; Reed, J Michael; Romero, L Michael

2017-10-01

Repeated exposure to acute stressors causes dramatic changes in an animal's stress physiology and the cumulative effects are often called chronic stress. Recently we showed that short-term exposure to weather-related stimuli, such as temperature change, artificial precipitation, and food restriction, cause acute responses in captive European starlings (Sturnus vulgaris). Here, we examined the effect of repeated exposure to weather-related stressors on heart rate and corticosterone (CORT) of captive non-molting and molting European starlings. Four times every day for 3 weeks, birds were exposed to either 30 min of a subtle (3°C) decrease in temperature, a short bout of simulated rain, or 2 hr of food removal. The order and time of presentation were randomly assigned on each day. We found no differences in heart rate or heart rate variability. Furthermore, there were no changes in baseline CORT levels, CORT negative feedback efficacy, or maximal adrenal capacity. Mass increased across the experimental period only in molting birds. CORT responses to restraint were decreased in both groups following treatment, suggesting the birds had downregulated their responses to acute stress. Molting birds showed evidence of suppression of the HPA axis compared with non-molting birds, which is consistent with previous research. Overall, our data show that repeated exposure to weather-related stressors does not elicit most of the symptoms normally associated with chronic stress. © 2018 Wiley Periodicals, Inc.

Neural processing of food and emotional stimuli in adolescent and adult anorexia nervosa patients.

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Horndasch, Stefanie; Roesch, Julie; Forster, Clemens; Dörfler, Arnd; Lindsiepe, Silja; Heinrich, Hartmut; Graap, Holmer; Moll, Gunther H; Kratz, Oliver

2018-01-01

A constant preoccupation with food and restrictive eating are main symptoms of anorexia nervosa (AN). Imaging studies revealed aberrant neural activation patterns in brain regions processing hedonic and reward reactions as well as-potentially aversive-emotions. An imbalance between so called "bottom-up" and "top-down" control areas is discussed. The present study is focusing on neural processing of disease-specific food stimuli and emotional stimuli and its developmental course in adolescent and adult AN patients and could offer new insight into differential mechanisms underlying shorter or more chronic disease. 33 adolescents aged 12-18 years (15 AN patients, 18 control participants) and 32 adult women (16 AN patients, 16 control participants) underwent functional magnetic resonance imaging (fMRI, 3T high-field scanner) while watching pictures of high and low-calorie food and affective stimuli. Afterwards, they rated subjective valence of each picture. FMRI data analysis was performed using a region of interest based approach. Pictures of high-calorie food items were rated more negatively by AN patients. Differences in activation between patients and controls were found in "bottom up" and "top down" control areas for food stimuli and in several emotion processing regions for affective stimuli which were more pronounced in adolescents than in adults. A differential pattern was seen for food stimuli compared to generally emotion eliciting stimuli. Adolescents with AN show reduced processing of affective stimuli and enhanced activation of regions involved in "bottom up" reward processing and "top down" control as well as the insula with regard to food stimuli with a focus on brain regions which underlie changes during adolescent development. In adults less clear and less specific activation differences were present, pointing towards a high impact that regions undergoing maturation might have on AN symptoms.

Neural processing of food and emotional stimuli in adolescent and adult anorexia nervosa patients

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Forster, Clemens; Dörfler, Arnd; Lindsiepe, Silja; Heinrich, Hartmut; Graap, Holmer; Moll, Gunther H.; Kratz, Oliver

2018-01-01

Background A constant preoccupation with food and restrictive eating are main symptoms of anorexia nervosa (AN). Imaging studies revealed aberrant neural activation patterns in brain regions processing hedonic and reward reactions as well as–potentially aversive–emotions. An imbalance between so called “bottom-up” and “top-down” control areas is discussed. The present study is focusing on neural processing of disease-specific food stimuli and emotional stimuli and its developmental course in adolescent and adult AN patients and could offer new insight into differential mechanisms underlying shorter or more chronic disease. Methods 33 adolescents aged 12–18 years (15 AN patients, 18 control participants) and 32 adult women (16 AN patients, 16 control participants) underwent functional magnetic resonance imaging (fMRI, 3T high-field scanner) while watching pictures of high and low-calorie food and affective stimuli. Afterwards, they rated subjective valence of each picture. FMRI data analysis was performed using a region of interest based approach. Results Pictures of high-calorie food items were rated more negatively by AN patients. Differences in activation between patients and controls were found in “bottom up” and “top down” control areas for food stimuli and in several emotion processing regions for affective stimuli which were more pronounced in adolescents than in adults. Conclusion A differential pattern was seen for food stimuli compared to generally emotion eliciting stimuli. Adolescents with AN show reduced processing of affective stimuli and enhanced activation of regions involved in “bottom up” reward processing and “top down” control as well as the insula with regard to food stimuli with a focus on brain regions which underlie changes during adolescent development. In adults less clear and less specific activation differences were present, pointing towards a high impact that regions undergoing maturation might have on AN

Beyond pleasure and arousal: appetitive erotic stimuli modulate electrophysiological brain correlates of early attentional processing.

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Kuhr, Benjamin; Schomberg, Jessica; Gruber, Thomas; Quirin, Markus

2013-03-27

Previous studies investigating affective reactions to pictures that elicit a specific effect have mainly focused on the dimensions valence and arousal. Using an event-related picture-viewing paradigm in electroencephalography, we investigated whether erotica - that is appetitive, evolutionarily relevant stimuli - have effects on early stages of attentional processing that are distinct from those of other positive and arousing stimuli. Seventeen male students viewed arousing photos of erotic, nude women or pictures of extreme sport scenes, as well as control pictures of attractive, dressed women or daily activities. Erotic pictures differed from extreme sport pictures not only in late but also in early attentional processes, as indicated by event-related potentials appearing from 130 ms after stimulus onset (P1). The findings suggest (a) that the dimension of appetence should be considered in addition to valence and arousal when investigating psychophysiological reactions to affective-motivational stimuli and (b) that early attentional processing as mirrored by the P1 can be influenced by motivational systems.

North-American norms for name disagreement: pictorial stimuli naming discrepancies.

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Mary O'Sullivan

Full Text Available Pictorial stimuli are commonly used by scientists to explore central processes; including memory, attention, and language. Pictures that have been collected and put into sets for these purposes often contain visual ambiguities that lead to name disagreement amongst subjects. In the present work, we propose new norms which reflect these sources of name disagreement, and we apply this method to two sets of pictures: the Snodgrass and Vanderwart (S&V set and the Bank of Standardized Stimuli (BOSS. Naming responses of the presented pictures were classified within response categories based on whether they were correct, incorrect, or equivocal. To characterize the naming strategy where an alternative name was being used, responses were further divided into different sub-categories that reflected various sources of name disagreement. Naming strategies were also compared across the two sets of stimuli. Results showed that the pictures of the S&V set and the BOSS were more likely to elicit alternative specific and equivocal names, respectively. It was also found that the use of incorrect names was not significantly different across stimulus sets but that errors were more likely caused by visual ambiguity in the S&V set and by a misuse of names in the BOSS. Norms for name disagreement presented in this paper are useful for subsequent research for their categorization and elucidation of name disagreement that occurs when choosing visual stimuli from one or both stimulus sets. The sources of disagreement should be examined carefully as they help to provide an explanation of errors and inconsistencies of many concepts during picture naming tasks.

[Effects of prefrontal ablations on the reaction of the active choice of feeder under different probability and value of the reinforcement on dog].

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Preobrazhenskaia, L A; Ioffe, M E; Mats, V N

2004-01-01

The role of the prefrontal cortex was investigated on the reaction of the active choice of the two feeders under changes value and probability reinforcement. The experiments were performed on 2 dogs with prefrontal ablation (g. proreus). Before the lesions the dogs were taught to receive food in two different feeders to conditioned stimuli with equally probable alimentary reinforcement. After ablation in the inter-trial intervals the dogs were running from the one feeder to another. In the answer to conditioned stimuli for many times the dogs choose the same feeder. The disturbance of the behavior after some times completely restored. In the experiments with competition of probability events and values of reinforcement the dogs chose the feeder with low-probability but better quality of reinforcement. In the experiments with equal value but different probability the intact dogs chose the feeder with higher probability. In our experiments the dogs with prefrontal lesions chose the each feeder equiprobably. Thus in condition of free behavior one of different functions of the prefrontal cortex is the reactions choose with more probability of reinforcement.

Examination of the effects of varenicline, bupropion, lorcaserin, or naltrexone on responding for conditioned reinforcement in nicotine-exposed rats.

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Guy, Elizabeth G; Fisher, Daniel C; Higgins, Guy A; Fletcher, Paul J

2014-12-01

Smoking tobacco remains one of the leading causes of preventable deaths in North America. Nicotine reinforces smoking behavior, in part, by enhancing the reinforcing properties of reward-related stimuli, or conditioned stimuli (CSs), associated with tobacco intake. To investigate how pharmaceutical interventions may affect this property of nicotine, we examined the effect of four US Food and Drug Administration (FDA) approved drugs on the ability of nicotine to enhance operant responding for a CS as a conditioned reinforcer. Thirsty rats were exposed to 13 Pavlovian sessions where a CS was paired with water delivery. Nicotine (0.4 mg/kg) injections were administered before each Pavlovian session. Then, in separate groups of rats, the effects of varenicline (1 mg/kg), bupropion (10 and 30 mg/kg), lorcaserin (0.6 mg/kg), and naltrexone (2 mg/kg), and their interaction with nicotine on responding for conditioned reinforcement were examined. Varenicline and lorcaserin each reduced nicotine-enhanced responding for conditioned reinforcement, whereas naltrexone had a modest effect of reducing response enhancements by nicotine. In contrast, bupropion enhanced the effect of nicotine on this measure. The results of these studies may inform how pharmaceutical interventions can affect smoking cessation attempts and relapse through diverse mechanisms, either substituting for, or interacting with, the reinforcement-enhancing properties of nicotine.

Responding for sucrose and wheel-running reinforcement: effect of pre-running.

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Belke, Terry W

2006-01-10

Six male albino Wistar rats were placed in running wheels and exposed to a fixed interval 30-s schedule that produced either a drop of 15% sucrose solution or the opportunity to run for 15s as reinforcing consequences for lever pressing. Each reinforcer type was signaled by a different stimulus. To assess the effect of pre-running, animals were allowed to run for 1h prior to a session of responding for sucrose and running. Results showed that, after pre-running, response rates in the later segments of the 30-s schedule decreased in the presence of a wheel-running stimulus and increased in the presence of a sucrose stimulus. Wheel-running rates were not affected. Analysis of mean post-reinforcement pauses (PRP) broken down by transitions between successive reinforcers revealed that pre-running lengthened pausing in the presence of the stimulus signaling wheel running and shortened pauses in the presence of the stimulus signaling sucrose. No effect was observed on local response rates. Changes in pausing in the presence of stimuli signaling the two reinforcers were consistent with a decrease in the reinforcing efficacy of wheel running and an increase in the reinforcing efficacy of sucrose. Pre-running decreased motivation to respond for running, but increased motivation to work for food.

Neural Conflict–Control Mechanisms Improve Memory for Target Stimuli

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Krebs, Ruth M.; Boehler, Carsten N.; De Belder, Maya; Egner, Tobias

2015-01-01

According to conflict-monitoring models, conflict serves as an internal signal for reinforcing top-down attention to task-relevant information. While evidence based on measures of ongoing task performance supports this idea, implications for long-term consequences, that is, memory, have not been tested yet. Here, we evaluated the prediction that conflict-triggered attentional enhancement of target-stimulus processing should be associated with superior subsequent memory for those stimuli. By combining functional magnetic resonance imaging (fMRI) with a novel variant of a face-word Stroop task that employed trial-unique face stimuli as targets, we were able to assess subsequent (incidental) memory for target faces as a function of whether a given face had previously been accompanied by congruent, neutral, or incongruent (conflicting) distracters. In line with our predictions, incongruent distracters not only induced behavioral conflict, but also gave rise to enhanced memory for target faces. Moreover, conflict-triggered neural activity in prefrontal and parietal regions was predictive of subsequent retrieval success, and displayed conflict-enhanced functional coupling with medial-temporal lobe regions. These data provide support for the proposal that conflict evokes enhanced top-down attention to task-relevant stimuli, thereby promoting their encoding into long-term memory. Our findings thus delineate the neural mechanisms of a novel link between cognitive control and memory. PMID:24108799

Cognitive appraisal of environmental stimuli induces emotion-like states in fish.

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Cerqueira, M; Millot, S; Castanheira, M F; Félix, A S; Silva, T; Oliveira, G A; Oliveira, C C; Martins, C I M; Oliveira, R F

2017-10-13

The occurrence of emotions in non-human animals has been the focus of debate over the years. Recently, an interest in expanding this debate to non-tetrapod vertebrates and to invertebrates has emerged. Within vertebrates, the study of emotion in teleosts is particularly interesting since they represent a divergent evolutionary radiation from that of tetrapods, and thus they provide an insight into the evolution of the biological mechanisms of emotion. We report that Sea Bream exposed to stimuli that vary according to valence (positive, negative) and salience (predictable, unpredictable) exhibit different behavioural, physiological and neuromolecular states. Since according to the dimensional theory of emotion valence and salience define a two-dimensional affective space, our data can be interpreted as evidence for the occurrence of distinctive affective states in fish corresponding to each the four quadrants of the core affective space. Moreover, the fact that the same stimuli presented in a predictable vs. unpredictable way elicited different behavioural, physiological and neuromolecular states, suggests that stimulus appraisal by the individual, rather than an intrinsic characteristic of the stimulus, has triggered the observed responses. Therefore, our data supports the occurrence of emotion-like states in fish that are regulated by the individual's perception of environmental stimuli.

The Lurking Snake in the Grass: Interference of Snake Stimuli in Visually Taxing Conditions

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Sandra Cristina Soares

2012-04-01

Full Text Available Based on evolutionary considerations, it was hypothesized that humans have been shaped to easily spot snakes in visually cluttered scenes that might otherwise hide camouflaged snakes. This hypothesis was tested in a visual search experiment in which I assessed automatic attention capture to evolutionarily-relevant distractor stimuli (snakes, in comparison with another animal which is also feared but where this fear has a disputed evolutionary origin (spiders, and neutral stimuli (mushrooms. Sixty participants were engaged in a task that involved the detection of a target (a bird among pictures of fruits. Unexpectedly, on some trials, a snake, a spider, or a mushroom replaced one of the fruits. The question of interest was whether the distracting stimuli slowed the reaction times for finding the target (the bird to different degrees. Perceptual load of the task was manipulated by increments in the set size (6 or 12 items on different trials. The findings showed that snake stimuli were processed preferentially, particularly under conditions where attentional resources were depleted, which reinforced the role of this evolutionarily-relevant stimulus in accessing the visual system (Isbell, 2009.

[WMN: a negative ERPs component related to working memory during non-target visual stimuli processing].

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Zhao, Lun; Wei, Jin-he

2003-10-01

To study non-target stimuli processing in the brain. Features of the event-related potentials (ERPs) from non-target stimuli during selective response task (SR) was compared with that during visual selective discrimination (DR) task in 26 normal subjects. The stimuli consisted of two color LED flashes (red and green) appeared randomly in left (LVF) or right (RVF) visual field with same probability. ERPs were derived at 9 electrode sites on the scalp under 2 task conditions: a) SR, making switch response to the target (NT) stimuli from LVF or RVF in one direction and making no response to the non-target (NT) ones; b) DR, making switching response to T stimuli differentially, i.e., to the left for T from LVF and to the right for T from RVF. 1) the non-target stimuli in DR conditions, compared with that in SR condition, elicited smaller P2 and P3 components and larger N2 component at the frontal brain areas; 2) a significant negative component, named as WMN (working memory negativity), appeared in the non-target ERPs during DR in the period of 100 to 700 ms post stimulation which was predominant at the frontal brain areas. According to the major difference between brain activities for non-target stimuli during SR and DR, the predominant appearance of WMN at the frontal brain areas demonstrated that the non-target stimulus processing was an active process and was related to working memory, i.e., the temporary elimination and the retrieval of the response mode which was stored in working memory.

Conditioned responses elicited by experimentally produced cues for smoking.

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Mucha, R F; Pauli, P; Angrilli, A

1998-03-01

Several theories of drug-craving postulate that a signal for drug elicits conditioned responses. However, depending on the theory, a drug cue is said to elicit drug similar, drug compensatory, positive motivational, and negative motivational effects. Since animal data alone cannot tease apart the relative importance of different cue-related processes in the addict, we developed and examined a model of drug cues in the human based on a two-sound, differential conditioning procedure using smoking as the reinforcer. After multiple pairings of a sound with smoking, there was a preference for the smoking cue on a conditioned preference test. The acute effects of smoking (increased heart rate, respiration rate, skin conductance level, skin conductance fluctuations, EEG beta power and trapezius EMG, decreased alpha power) were not affected by the smoking cue, although subjects drew more on their cigarette in the presence of the smoking cue than in the presence of a control cue. Moreover, the cue did not change baseline behaviour except for a possible increase in EEG beta power and an increase in trapezius EMG at about the time when smoking should have occurred. The findings confirm the value of experimental models of drug cues in the human for comparing different cue phenomena in the dependent individual. They indicate that an acquired signal for drug in the human may elicit incentive motivational effects and associated preparatory motor responses in addition to possible conditioned tolerance.

Non-target adjacent stimuli classification improves performance of classical ERP-based brain computer interface

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Ceballos, G. A.; Hernández, L. F.

2015-04-01

Objective. The classical ERP-based speller, or P300 Speller, is one of the most commonly used paradigms in the field of Brain Computer Interfaces (BCI). Several alterations to the visual stimuli presentation system have been developed to avoid unfavorable effects elicited by adjacent stimuli. However, there has been little, if any, regard to useful information contained in responses to adjacent stimuli about spatial location of target symbols. This paper aims to demonstrate that combining the classification of non-target adjacent stimuli with standard classification (target versus non-target) significantly improves classical ERP-based speller efficiency. Approach. Four SWLDA classifiers were trained and combined with the standard classifier: the lower row, upper row, right column and left column classifiers. This new feature extraction procedure and the classification method were carried out on three open databases: the UAM P300 database (Universidad Autonoma Metropolitana, Mexico), BCI competition II (dataset IIb) and BCI competition III (dataset II). Main results. The inclusion of the classification of non-target adjacent stimuli improves target classification in the classical row/column paradigm. A gain in mean single trial classification of 9.6% and an overall improvement of 25% in simulated spelling speed was achieved. Significance. We have provided further evidence that the ERPs produced by adjacent stimuli present discriminable features, which could provide additional information about the spatial location of intended symbols. This work promotes the searching of information on the peripheral stimulation responses to improve the performance of emerging visual ERP-based spellers.

Transient and sustained cortical activity elicited by connected speech of varying intelligibility

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Tiitinen Hannu

2012-12-01

Full Text Available Abstract Background The robustness of speech perception in the face of acoustic variation is founded on the ability of the auditory system to integrate the acoustic features of speech and to segregate them from background noise. This auditory scene analysis process is facilitated by top-down mechanisms, such as recognition memory for speech content. However, the cortical processes underlying these facilitatory mechanisms remain unclear. The present magnetoencephalography (MEG study examined how the activity of auditory cortical areas is modulated by acoustic degradation and intelligibility of connected speech. The experimental design allowed for the comparison of cortical activity patterns elicited by acoustically identical stimuli which were perceived as either intelligible or unintelligible. Results In the experiment, a set of sentences was presented to the subject in distorted, undistorted, and again in distorted form. The intervening exposure to undistorted versions of sentences rendered the initially unintelligible, distorted sentences intelligible, as evidenced by an increase from 30% to 80% in the proportion of sentences reported as intelligible. These perceptual changes were reflected in the activity of the auditory cortex, with the auditory N1m response (~100 ms being more prominent for the distorted stimuli than for the intact ones. In the time range of auditory P2m response (>200 ms, auditory cortex as well as regions anterior and posterior to this area generated a stronger response to sentences which were intelligible than unintelligible. During the sustained field (>300 ms, stronger activity was elicited by degraded stimuli in auditory cortex and by intelligible sentences in areas posterior to auditory cortex. Conclusions The current findings suggest that the auditory system comprises bottom-up and top-down processes which are reflected in transient and sustained brain activity. It appears that analysis of acoustic features occurs

Comparison of bone-conducted vibration for eliciting ocular vestibular-evoked myogenic potentials: forehead versus mastoid tapping.

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Tseng, Chia-Chen; Wang, Shou-Jen; Young, Yi-Ho

2012-02-01

This study compared bone-conducted vibration (BCV) stimuli at forehead (Fz) and mastoid sites for eliciting ocular vestibular-evoked myogenic potentials (oVEMPs). Prospective study. University hospital. Twenty healthy subjects underwent oVEMP testing via BCV stimuli at Fz and mastoid sites. Another 50 patients with unilateral Meniere's disease also underwent oVEMP testing. All healthy subjects showed clear oVEMPs via BCV stimulation regardless of the tapping sites. The right oVEMPs stimulated by tapping at the right mastoid had earlier nI and pI latencies and a larger nI-pI amplitude compared with those stimulated by tapping at the Fz and left mastoid. Similar trends were also observed in left oVEMPs. However, the asymmetry ratio did not differ significantly between the ipsilateral mastoid and Fz sites. Clinically, tapping at the Fz revealed absent oVEMPs in 28% of Meniere's ears, which decreased to 16% when tapping at the ipsilesional (hydropic) mastoid site, exhibiting a significant difference. Tapping at the ipsilateral mastoid site elicits earlier oVEMP latencies and larger oVEMP amplitudes when compared with tapping at the Fz site. Thus, tapping at the Fz site is suggested to screen for the otolithic function, whereas tapping at the ipsilesional mastoid site is suitable for evaluating residual otolithic function.

Diffuse optical tomography activation in the somatosensory cortex: specific activation by painful vs. non-painful thermal stimuli.

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Lino Becerra

2009-11-01

Full Text Available Pain is difficult to assess due to the subjective nature of self-reporting. The lack of objective measures of pain has hampered the development of new treatments as well as the evaluation of current ones. Functional MRI studies of pain have begun to delineate potential brain response signatures that could be used as objective read-outs of pain. Using Diffuse Optical Tomography (DOT, we have shown in the past a distinct DOT signal over the somatosensory cortex to a noxious heat stimulus that could be distinguished from the signal elicited by innocuous mechanical stimuli. Here we further our findings by studying the response to thermal innocuous and noxious stimuli.Innocuous and noxious thermal stimuli were applied to the skin of the face of the first division (ophthalmic of the trigeminal nerve in healthy volunteers (N = 6. Stimuli temperatures were adjusted for each subject to evoke warm (equivalent to a 3/10 and painful hot (7/10 sensations in a verbal rating scale (0/10 = no/max pain. A set of 26 stimuli (5 sec each was applied for each temperature with inter-stimulus intervals varied between 8 and 15 sec using a Peltier thermode. A DOT system was used to capture cortical responses on both sides of the head over the primary somatosensory cortical region (S1. For the innocuous stimuli, group results indicated mainly activation on the contralateral side with a weak ipsilateral response. For the noxious stimuli, bilateral activation was observed with comparable amplitudes on both sides. Furthermore, noxious stimuli produced a temporal biphasic response while innocuous stimuli produced a monophasic response.These results are in accordance with fMRI and our other DOT studies of innocuous mechanical and noxious heat stimuli. The data indicate the differentiation of DOT cortical responses for pain vs. innocuous stimuli that may be useful in assessing objectively acute pain.

Differential impact of pavlovian drug conditioned stimuli on in vivo dopamine transmission in the rat accumbens shell and core and in the prefrontal cortex.

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Bassareo, Valentina; De Luca, Maria Antonietta; Di Chiara, Gaetano

2007-04-01

Conditioned stimuli (CSs) by pavlovian association with reinforcing drugs (US) are thought to play an important role in the acquisition, maintenance and relapse of drug dependence. The aim of this study was to investigate by microdialysis the impact of pavlovian drug CSs on behaviour and on basal and drug-stimulated dopamine (DA) in three terminal DA areas: nucleus accumbens shell, core and prefrontal cortex (PFCX). Conditioned rats were trained once a day for 3 days by presentation of Fonzies filled box (FFB, CS) for 10 min followed by administration of morphine (1 mg/kg), nicotine (0.4 mg/kg) or saline, respectively. Pseudo-conditioned rats were presented with the FFB 10 h after drug or saline administration. Rats were implanted with microdialysis probes in the shell, core and PFCX. The effect of stimuli conditioned with morphine and nicotine on DA and on DA response to drugs was studied. Drug CSs elicited incentive reactions and released DA in the shell and PFCX but not in the core. Pre-exposure to morphine CS potentiated DA release to morphine challenge in the shell but not in the core and PFCX. This effect was related to the challenge dose of morphine and was stimulus-specific since a food CS did not potentiate the shell DA response to morphine. Pre-exposure to nicotine CS potentiated DA release in the shell and PFCX. The results show that drug CSs stimulate DA release in the shell and medial PFCX and specifically potentiate the primary stimulant drug effects on DA transmission.

No impact of repeated extinction exposures on operant responding maintained by different reinforcer rates.

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Bai, John Y H; Podlesnik, Christopher A

2017-05-01

Greater rates of intermittent reinforcement in the presence of discriminative stimuli generally produce greater resistance to extinction, consistent with predictions of behavioral momentum theory. Other studies reveal more rapid extinction with higher rates of reinforcers - the partial reinforcement extinction effect. Further, repeated extinction often produces more rapid decreases in operant responding due to learning a discrimination between training and extinction contingencies. The present study examined extinction repeatedly with training with different rates of intermittent reinforcement in a multiple schedule. We assessed whether repeated extinction would reverse the pattern of greater resistance to extinction with greater reinforcer rates. Counter to this prediction, resistance to extinction was consistently greater across twelve assessments of training followed by six successive sessions of extinction. Moreover, patterns of responding during extinction resembled those observed during satiation tests, which should not alter discrimination processes with repeated testing. These findings join others suggesting operant responding in extinction can be durable across repeated tests. Copyright © 2017 Elsevier B.V. All rights reserved.

The interplay between the anticipation and subsequent online processing of emotional stimuli as measured by pupillary dilatation: the role of cognitive reappraisal

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Marie-Anne eVanderhasselt

2014-03-01

Full Text Available Emotions can occur during an emotion-eliciting event, but they can also arise when anticipating the event. We used pupillary responses, as a measure of effortful cognitive processing, to test whether the anticipation of an emotional stimulus (positive and negative influences the subsequent online processing of that emotional stimulus. Moreover, we tested whether individual differences in the habitual use of emotion regulation strategies are associated with pupillary responses during the anticipation and/or online processing of this emotional stimulus. Our results show that, both for positive and negative stimuli, pupillary diameter during the anticipation of emotion-eliciting events is inversely and strongly correlated to pupillary responses during the emotional image presentation. The variance in this temporal interplay between anticipation and online processing was related to individual differences in emotion regulation. Specifically, the results show that high reappraisal scores are related to larger pupil diameter during the anticipation and subsequent smaller pupillary responses during the online processing of emotion-eliciting events. The habitual use of expressive suppression was not associated to pupillary responses in the anticipation and subsequent online processing of emotional stimuli. All together, the current data suggest (most strongly for individuals scoring high on the habitual use of reappraisal that larger pupillary responses during the anticipation of an emotional stimulus are indicative of a sustained attentional set activation to prepare for an upcoming emotional stimulus, which subsequently directs a reduced need to cognitively process that emotional event. Because the habitual use of reappraisal is known to have a positive influence on emotional well-being, the interplay between anticipation and online processing of emotional stimuli might be a significant marker of this well-being.

The interplay between the anticipation and subsequent online processing of emotional stimuli as measured by pupillary dilatation: the role of cognitive reappraisal.

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Vanderhasselt, Marie-Anne; Remue, Jonathan; Ng, Kwun Kei; De Raedt, Rudi

2014-01-01

Emotions can occur during an emotion-eliciting event, but they can also arise when anticipating the event. We used pupillary responses, as a measure of effortful cognitive processing, to test whether the anticipation of an emotional stimulus (positive and negative) influences the subsequent online processing of that emotional stimulus. Moreover, we tested whether individual differences in the habitual use of emotion regulation strategies are associated with pupillary responses during the anticipation and/or online processing of this emotional stimulus. Our results show that, both for positive and negative stimuli, pupillary diameter during the anticipation of emotion-eliciting events is inversely and strongly correlated to pupillary responses during the emotional image presentation. The variance in this temporal interplay between anticipation and online processing was related to individual differences in emotion regulation. Specifically, the results show that high reappraisal scores are related to larger pupil diameter during the anticipation which is related to smaller pupillary responses during the online processing of emotion-eliciting events. The habitual use of expressive suppression was not associated to pupillary responses in the anticipation and subsequent online processing of emotional stimuli. Taken together, the current data suggest (most strongly for individuals scoring high on the habitual use of reappraisal) that larger pupillary responses during the anticipation of an emotional stimulus are indicative of a sustained attentional set activation to prepare for an upcoming emotional stimulus, which subsequently directs a reduced need to cognitively process that emotional event. Hence, because the habitual use of reappraisal is known to have a positive influence on emotional well-being, the interplay between anticipation and online processing of emotional stimuli might be a significant marker of this well-being.

Viewing socio-affective stimuli increases connectivity within an extended default mode network.

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Göttlich, Martin; Ye, Zheng; Rodriguez-Fornells, Antoni; Münte, Thomas F; Krämer, Ulrike M

2017-03-01

Empathy is an essential ability for prosocial behavior. Previous imaging studies identified a number of brain regions implicated in affective and cognitive aspects of empathy. In this study, we investigated the neural correlates of empathy from a network perspective using graph theory and beta-series correlations. Two independent data sets were acquired using the same paradigm that elicited empathic responses to socio-affective stimuli. One data set was used to define the network nodes and modular structure, the other data set was used to investigate the effects of emotional versus neutral stimuli on network connectivity. Emotional relative to neutral stimuli increased connectivity between 74 nodes belonging to different networks. Most of these nodes belonged to an extended default mode network (eDMN). The other nodes belonged to a cognitive control network or visual networks. Within the eDMN, posterior STG/TPJ regions were identified as provincial hubs. The eDMN also showed stronger connectivity to the cognitive control network encompassing lateral PFC regions. Connector hubs between the two networks were posterior cingulate cortex and ventrolateral PFC. This stresses the advantage of a network approach as regions similarly modulated by task conditions can be dissociated into distinct networks and regions crucial for network integration can be identified. Copyright © 2017 Elsevier Inc. All rights reserved.

Neural conflict-control mechanisms improve memory for target stimuli.

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Krebs, Ruth M; Boehler, Carsten N; De Belder, Maya; Egner, Tobias

2015-03-01

According to conflict-monitoring models, conflict serves as an internal signal for reinforcing top-down attention to task-relevant information. While evidence based on measures of ongoing task performance supports this idea, implications for long-term consequences, that is, memory, have not been tested yet. Here, we evaluated the prediction that conflict-triggered attentional enhancement of target-stimulus processing should be associated with superior subsequent memory for those stimuli. By combining functional magnetic resonance imaging (fMRI) with a novel variant of a face-word Stroop task that employed trial-unique face stimuli as targets, we were able to assess subsequent (incidental) memory for target faces as a function of whether a given face had previously been accompanied by congruent, neutral, or incongruent (conflicting) distracters. In line with our predictions, incongruent distracters not only induced behavioral conflict, but also gave rise to enhanced memory for target faces. Moreover, conflict-triggered neural activity in prefrontal and parietal regions was predictive of subsequent retrieval success, and displayed conflict-enhanced functional coupling with medial-temporal lobe regions. These data provide support for the proposal that conflict evokes enhanced top-down attention to task-relevant stimuli, thereby promoting their encoding into long-term memory. Our findings thus delineate the neural mechanisms of a novel link between cognitive control and memory. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

A new multifeature mismatch negativity (MMN) paradigm for the study of music perception with more real-sounding stimuli

DEFF Research Database (Denmark)

Quiroga Martinez, David Ricardo; Hansen, Niels Christian; Højlund, Andreas

. Interestingly, this reduction did not hold for mistunings and slide in the melody, probably due to interval mistuning and the high voice superiority effect. Our results indicate that it is possible to use the MMN for the study of more real-sounding music and that stimulus complexity plays a crucial role......The MMN is a brain response elicited by deviants in a series of repetitive sounds that has been valuable for the study of music perception. However, most MMN experimental designs use simple tone patterns as stimuli, failing to represent the complexity of everyday music. Our goal was to develop...... a new paradigm using more real-sounding stimuli. Concretely, we wanted to assess the perception of nonrepetitive melodies when presented alone and when embedded in two-part music. An Alberti bass used previously served both as a comparison and as the second voice in the two-part stimuli. We used MEG...

Automatic affective appraisal of sexual penetration stimuli in women with vaginismus or dyspareunia.

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Huijding, Jorg; Borg, Charmaine; Weijmar-Schultz, Willibrord; de Jong, Peter J

2011-03-01

Current psychological views are that negative appraisals of sexual stimuli lie at the core of sexual dysfunctions. It is important to differentiate between deliberate appraisals and more automatic appraisals, as research has shown that the former are most relevant to controllable behaviors, and the latter are most relevant to reflexive behaviors. Accordingly, it can be hypothesized that in women with vaginismus, the persistent difficulty to allow vaginal entry is due to global negative automatic affective appraisals that trigger reflexive pelvic floor muscle contraction at the prospect of penetration. To test whether sexual penetration pictures elicited global negative automatic affective appraisals in women with vaginismus or dyspareunia and to examine whether deliberate appraisals and automatic appraisals differed between the two patient groups. Women with persistent vaginismus (N = 24), dyspareunia (N = 23), or no sexual complaints (N = 30) completed a pictorial Extrinsic Affective Simon Task (EAST), and then made a global affective assessment of the EAST stimuli using visual analogue scales (VAS). The EAST assessed global automatic affective appraisals of sexual penetration stimuli, while the VAS assessed global deliberate affective appraisals of these stimuli. Automatic affective appraisals of sexual penetration stimuli tended to be positive, independent of the presence of sexual complaints. Deliberate appraisals of the same stimuli were significantly more negative in the women with vaginismus than in the dyspareunia group and control group, while the latter two groups did not differ in their appraisals. Unexpectedly, deliberate appraisals seemed to be most important in vaginismus, whereas dyspareunia did not seem to implicate negative deliberate or automatic affective appraisals. These findings dispute the view that global automatic affect lies at the core of vaginismus and indicate that a useful element in therapeutic interventions may be the modification of

Pharmacological stimuli decreasing nucleus accumbens dopamine can act as positive reinforcers but have a low addictive potential.

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Marinelli, M; Barrot, M; Simon, H; Oberlander, C; Dekeyne, A; Le Moal, M; Piazza, P V

1998-10-01

Opioid peptides, through mu and delta receptors, play an important part in reward. In contrast, the role of kappa receptors is more controversial. We examined the possible positive reinforcing effects of a selective kappa agonist, RU 51599, by studying intravenous self-administration in the rat. The effect of RU 51599 on dopamine release in the nucleus accumbens was also studied, as opioids and dopamine seem to interact in the mediation of reward. The behavioural and dopaminergic effects of RU 51599 were compared with those of the mu agonist heroin. Rats self-administered both RU 51599 (6.5, 20 and 60 microg/inj) and heroin (30 microg/inj) at low ratio requirement. When the ratio requirement, i.e. the number of responses necessary to receive one drug infusion, was increased, self-administration of RU 51599 rapidly extinguished, whereas self-administration of heroin was maintained. Intravenous infusion of RU 51599 (100, 200 and 400 microg) dose-dependently decreased (25, 30 and 40%, respectively) extracellular concentrations of dopamine, as measured by means of microdialysis in freely moving rats. In contrast, heroin increased accumbens dopamine (130% over baseline). These results indicate that kappa receptors, similarly to mu ones, can mediate positive reinforcing effects of opioid peptides. However, the strength of the reinforcement is very low for kappa receptors. This suggests that changes in accumbens dopamine do not correlate with the capacity of a stimulus to induce reward or aversion. In contrast, a parallel seems to exist between an increase in accumbens dopamine and the drive to reach or obtain a positive reinforcer.

How Does Adult Attachment Affect Human Recognition of Love-related and Sex-related Stimuli: An ERP Study

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Hou, Juan; Chen, Xin; Liu, Jinqun; Yao, Fangshu; Huang, Jiani; Ndasauka, Yamikani; Ma, Ru; Zhang, Yuting; Lan, Jing; Liu, Lu; Fang, Xiaoyi

2016-01-01

In the present study, we investigated the relationship among three emotion-motivation systems (adult attachment, romantic love, and sex). We recorded event-related potentials in 37 healthy volunteers who had experienced romantic love while they viewed SEX, LOVE, FRIEND, SPORT, and NEUTRAL images. We also measured adult attachment styles, level of passionate love and sexual attitudes. As expected, results showed that, firstly, response to love-related image-stimuli and sex-related image-stimuli on the electrophysiological data significantly different on N1, N2, and positive slow wave (PSW) components. Secondly, the different adult attachment styles affected individuals’ recognition processing in response to love-related and sex-related images, especially, to sex-related images. Further analysis showed that voltages elicited by fearful attachment style individuals were significantly lower than voltages elicited by secure and dismissing attachment style individuals on sex-related images at frontal sites, on N1 and N2 components. Thirdly, from behavior data, we found that adult attachment styles were not significantly related to any dimension of sexual attitudes but were significantly related to passionate love scale (PLS) total points. Thus, the behavior results were not in line with the electrophysiological results. The present study proved that adult attachment styles might mediate individuals’ lust and attraction systems. PMID:27199830

Correlation between MEG and BOLD fMRI signals induced by visual flicker stimuli

Institute of Scientific and Technical Information of China (English)

Chu Renxin; Holroyd Tom; Duyn Jeff

2007-01-01

The goal of this work was to investigate how the MEG signal amplitude correlates with that of BOLD fMRI.To investigate the correlation between fMRI and macroscopic electrical activity, BOLD fMRI and MEG was performed on the same subjects (n =5). A visual flicker stimulus of varying temporal frequency was used to elicit neural responses in early visual areas. A strong similarity was observed in frequency tuning curves between both modalities.Although, averaged over subjects, the BOLD tuning curve was somewhat broader than MEG, both BOLD and MEG had maxima at a flicker frequency of 10 Hz. Also, we measured the first and second harmonic components as the stimuli frequency by MEG. In the low stimuli frequency (less than 6 Hz), the second harmonic has comparable amplitude with the first harmonic, which implies that neural frequency response is nonlinear and has more nonlinear components in low frequency than in high frequency.

Stimulus control: Part I

OpenAIRE

Dinsmoor, James A.

1995-01-01

In his effort to distinguish operant from respondent conditioning, Skinner stressed the lack of an eliciting stimulus and rejected the prevailing stereotype of Pavlovian “stimulus—response” psychology. But control by antecedent stimuli, whether classified as conditional or discriminative, is ubiquitous in the natural setting. With both respondent and operant behavior, symmetrical gradients of generalization along unrelated dimensions may be obtained following differential reinforcement in the...

Instructional control of reinforcement learning: a behavioral and neurocomputational investigation.

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Doll, Bradley B; Jacobs, W Jake; Sanfey, Alan G; Frank, Michael J

2009-11-24

Humans learn how to behave directly through environmental experience and indirectly through rules and instructions. Behavior analytic research has shown that instructions can control behavior, even when such behavior leads to sub-optimal outcomes (Hayes, S. (Ed.). 1989. Rule-governed behavior: cognition, contingencies, and instructional control. Plenum Press.). Here we examine the control of behavior through instructions in a reinforcement learning task known to depend on striatal dopaminergic function. Participants selected between probabilistically reinforced stimuli, and were (incorrectly) told that a specific stimulus had the highest (or lowest) reinforcement probability. Despite experience to the contrary, instructions drove choice behavior. We present neural network simulations that capture the interactions between instruction-driven and reinforcement-driven behavior via two potential neural circuits: one in which the striatum is inaccurately trained by instruction representations coming from prefrontal cortex/hippocampus (PFC/HC), and another in which the striatum learns the environmentally based reinforcement contingencies, but is "overridden" at decision output. Both models capture the core behavioral phenomena but, because they differ fundamentally on what is learned, make distinct predictions for subsequent behavioral and neuroimaging experiments. Finally, we attempt to distinguish between the proposed computational mechanisms governing instructed behavior by fitting a series of abstract "Q-learning" and Bayesian models to subject data. The best-fitting model supports one of the neural models, suggesting the existence of a "confirmation bias" in which the PFC/HC system trains the reinforcement system by amplifying outcomes that are consistent with instructions while diminishing inconsistent outcomes.

Multiple determinants of transfer of evaluative function after conditioning with free-operant schedules of reinforcement.

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Dack, Charlotte; Reed, Phil; McHugh, Louise

2010-11-01

The aim of the four present experiments was to explore how different schedules of reinforcement influence schedule-induced behavior, their impact on evaluative ratings given to conditioned stimuli associated with each schedule through evaluative conditioning, and the transfer of these evaluations through derived stimulus networks. Experiment 1 compared two contrasting response reinforcement rules (variable ratio [VR], variable interval [VI]). Experiment 2 varied the response to reinforcement rule between two schedules but equated the outcome to response rate (differential reinforcement of high rate [DRH] vs. VR). Experiment 3 compared molar and molecular aspects of contingencies of reinforcement (tandem VIVR vs. tandem VRVI). Finally, Experiment 4 employed schedules that induced low rates of responding to determine whether, under these circumstances, responses were more sensitive to the molecular aspects of a schedule (differential reinforcement of low rate [DRL] vs. VI). The findings suggest that the transfer of evaluative functions is determined mainly by differences in response rate between the schedules and the molar aspects of the schedules. However, when neither schedule was based on a strong response reinforcement rule, the transfer of evaluative judgments came under the control of the molecular aspects of the schedule.

Abnormal decision-making in generalized anxiety disorder: Aversion of risk or stimulus-reinforcement impairment?

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Teng, Cindy; Otero, Marcela; Geraci, Marilla; Blair, R J R; Pine, Daniel S; Grillon, Christian; Blair, Karina S

2016-03-30

There is preliminary data indicating that patients with generalized anxiety disorder (GAD) show impairment on decision-making tasks requiring the appropriate representation of reinforcement value. The current study aimed to extend this literature using the passive avoidance (PA) learning task, where the participant has to learn to respond to stimuli that engender reward and avoid responding to stimuli that engender punishment. Six stimuli engendering reward and six engendering punishment are presented once per block for 10 blocks of trials. Thirty-nine medication-free patients with GAD and 29 age-, IQ and gender matched healthy comparison individuals performed the task. In addition, indexes of social functioning as assessed by the Global Assessment of Functioning (GAF) scale were obtained to allow for correlational analyzes of potential relations between cognitive and social impairments. The results revealed a Group-by-Error Type-by-Block interaction; patients with GAD committed significantly more commission (passive avoidance) errors than comparison individuals in the later blocks (blocks 7,8, and 9). In addition, the extent of impairment on these blocks was associated with their functional impairment as measured by the GAF scale. These results link GAD with anomalous decision-making and indicate that a potential problem in reinforcement representation may contribute to the severity of expression of their disorder. Copyright © 2016. Published by Elsevier Ireland Ltd.

Middle latency response correlates of single and double deviant stimuli in a multi-feature paradigm.

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Althen, H; Huotilainen, M; Grimm, S; Escera, C

2016-01-01

This study aimed to test single and double deviance-related modulations of the middle latency response (MLR) and the applicability of the optimum-2 multi-feature paradigm. The MLR and the MMN to frequency, intensity and double-feature deviants of an optimum-2 multi-feature paradigm and the MMN to double-feature deviants of an oddball paradigm were recorded in young adults. Double deviants elicited significant enhancements of the Nb and Pb MLR waves compared with the waves elicited by standard stimuli. These enhancements equalled approximately the sum of the numerical amplitude differences elicited by the single deviants. In contrast, the MMN to double deviants did not show such additivity. MMNs elicited by double deviants of the multi-feature and the oddball paradigm showed no significant difference in amplitude or latency. The optimum-2 multi-feature paradigm is suitable for recording double deviance-related modulations of the MLR. Interspersed intensity and frequency deviants in the standard trace of the optimum-2 condition multi-feature paradigm did not weaken the double MMN. The optimum-2 multi-feature paradigm could be especially beneficial for clinical studies on early deviance-related modulations in the MLR, due to its optimized utilization of the recording time. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Viewing pain and happy faces elicited similar changes in postural body sway.

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Juan Gea

Full Text Available Affective facial expressions are potent social cues that can induce relevant physiological changes, as well as behavioral dispositions in the observer. Previous studies have revealed that angry faces induced significant reductions in body sway as compared with neutral and happy faces, reflecting an avoidance behavioral tendency as freezing. The expression of pain is usually considered an unpleasant stimulus, but also a relevant cue for delivering effective care and social support. Nevertheless, there are few data about behavioral dispositions elicited by the observation of pain expressions in others. The aim of the present research was to evaluate approach-avoidance tendencies by using video recordings of postural body sway when participants were standing and observing facial expressions of pain, happy and neutral. We hypothesized that although pain faces would be rated as more unpleasant than the other faces, they would provoke significant changes in postural body sway as compared to neutral facial expressions. Forty healthy female volunteers (mean age 25 participated in the study. Amplitude of forward movements and backward movements in the anterior-posterior and medial-lateral axes were obtained. Statistical analyses revealed that pain faces were the most unpleasant stimuli, and that both happy and pain faces were more arousing than neutral ones. Happy and pain faces also elicited greater amplitude of body sway in the anterior-posterior axes as compared with neutral faces. In addition, significant positive correlations were found between body sway elicited by pain faces and pleasantness and empathic ratings, suggesting that changes in postural body sway elicited by pain faces might be associated with approach and cooperative behavioral responses.

A Review of the Relationship between Novelty, Intrinsic Motivation and Reinforcement Learning

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Siddique Nazmul

2017-11-01

Full Text Available This paper presents a review on the tri-partite relationship between novelty, intrinsic motivation and reinforcement learning. The paper first presents a literature survey on novelty and the different computational models of novelty detection, with a specific focus on the features of stimuli that trigger a Hedonic value for generating a novelty signal. It then presents an overview of intrinsic motivation and investigations into different models with the aim of exploring deeper co-relationships between specific features of a novelty signal and its effect on intrinsic motivation in producing a reward function. Finally, it presents survey results on reinforcement learning, different models and their functional relationship with intrinsic motivation.

Cognitive conflict increases processing of negative, task-irrelevant stimuli.

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Ligeza, Tomasz S; Wyczesany, Miroslaw

2017-10-01

The detection of cognitive conflict is thought to trigger adjustments in executive control. It has been recently shown that cognitive conflict increases processing of stimuli that are relevant to the ongoing task and that these modulations are exerted by the dorsolateral prefrontal cortex (DLPFC). However, it is still unclear whether such control influences are unspecific and might also affect the processing of task-irrelevant stimuli. The aim of the study was to examine if cognitive conflict affects processing of neutral and negative, task-irrelevant pictures. Participants responded to congruent (non-conflict) or to incongruent (conflict-eliciting) trials of a modified flanker task. Each response was followed by a presentation of a neutral or negative picture. The late positive potential (LPP) in response to picture presentation was used to assess the level of picture processing after conflict vs non-conflict trials. Connectivity between the DLPFC and attentional and perceptual areas during picture presentation was analysed to check if the DLPFC might be a source of these modulations. ERP results showed an effect of cognitive conflict only on processing of negative pictures: LPP in response to negative pictures was increased after conflict trials, whereas LPP in response to neutral pictures remained unchanged. Cortical connectivity analysis showed that conflict trials intensified information flow from the DLPFC towards attentional and perceptual regions. Results suggest that cognitive conflict increases processing of task-irrelevant stimuli; however, they must display high biological salience. Increase in cognitive control exerted by the DLPFC over attentional and perceptual regions is a probable mechanism of the effect. Copyright © 2017 Elsevier B.V. All rights reserved.

Mechanism of norepinephrine release elicited by renal nerve stimulation, veratridine and potassium chloride in the isolated rat kidney

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el-Din, M.M.; Malik, K.U.

1987-01-01

We have investigated the mechanism by which renal nerve stimulation (RNS), veratridine (Vt) and KCl promote release of norepinephrine in the isolated rat kidney perfused with Tyrode's solution and prelabeled with [ 3 H]norepinephrine by examining the overflow of tritium elicited by these stimuli during 1) extracellular Ca++ depletion, 2) alterations in extracellular Na+ concentration and 3) administration of tetrodotoxin, amiloride, LiCl and calcium channel blockers. RNS (1-4 Hz), Vt (15-90 nmol) and KCl (150-500 mumol) produced renal vasoconstriction and enhanced the tritium overflow in a frequency- and concentration-dependent manner, respectively. Omission of Ca++ (1.8 mM) from the perfusion fluid abolished the renal vasoconstriction and the increase in tritium overflow elicited by RNA and KCl and substantially reduced that caused by Vt. Lowering the Na+ concentration in the perfusion medium (from 150 to 25 mM) reduced the overflow of tritium and the renal vasoconstriction caused by RNS (2 Hz) or Vt (45 nmol); the increase in tritium overflow in response to these stimuli was positively correlated with extracellular Na+ (25-150 mM). In contrast, KCl-induced tritium overflow was negatively correlated with extracellular Na+ concentration. Tetrodotoxin (0.3 microM) abolished the effect of RNS and Vt, but not that of KCl, to increase overflow of tritium and to produce renal vasoconstriction. Administration of amiloride (180 microM) enhanced the overflow of tritium but attenuated the associated renal vasoconstriction produced by RNS, Vt and KCl. Replacement of NaCl (75 mM) with equimolar concentration of LiCl enhanced the overflow of tritium elicited by RNS, Vt and KCl; the associated renal vasoconstriction remained unaltered

Different types of theta rhythmicity are induced by social and fearful stimuli in a network associated with social memory.

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Tendler, Alex; Wagner, Shlomo

2015-02-16

Rhythmic activity in the theta range is thought to promote neuronal communication between brain regions. In this study, we performed chronic telemetric recordings in socially behaving rats to monitor electrophysiological activity in limbic brain regions linked to social behavior. Social encounters were associated with increased rhythmicity in the high theta range (7-10 Hz) that was proportional to the stimulus degree of novelty. This modulation of theta rhythmicity, which was specific for social stimuli, appeared to reflect a brain-state of social arousal. In contrast, the same network responded to a fearful stimulus by enhancement of rhythmicity in the low theta range (3-7 Hz). Moreover, theta rhythmicity showed different pattern of coherence between the distinct brain regions in response to social and fearful stimuli. We suggest that the two types of stimuli induce distinct arousal states that elicit different patterns of theta rhythmicity, which cause the same brain areas to communicate in different modes.

Neural systems underlying aversive conditioning in humans with primary and secondary reinforcers

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Mauricio R Delgado

2011-05-01

Full Text Available Money is a secondary reinforcer commonly used across a range of disciplines in experimental paradigms investigating reward learning and decision-making. The effectiveness of monetary reinforcers during aversive learning and its neural basis, however, remains a topic of debate. Specifically, it is unclear if the initial acquisition of aversive representations of monetary losses depends on similar neural systems as more traditional aversive conditioning that involves primary reinforcers. This study contrasts the efficacy of a biologically defined primary reinforcer (shock and a socially defined secondary reinforcer (money during aversive learning and its associated neural circuitry. During a two-part experiment, participants first played a gambling game where wins and losses were based on performance to gain an experimental bank. Participants were then exposed to two separate aversive conditioning sessions. In one session, a primary reinforcer (mild shock served as an unconditioned stimulus (US and was paired with one of two colored squares, the conditioned stimuli (CS+ and CS-, respectively. In another session, a secondary reinforcer (loss of money served as the US and was paired with one of two different CS. Skin conductance responses were greater for CS+ compared to CS- trials irrespective of type of reinforcer. Neuroimaging results revealed that the striatum, a region typically linked with reward-related processing, was found to be involved in the acquisition of aversive conditioned response irrespective of reinforcer type. In contrast, the amygdala was involved during aversive conditioning with primary reinforcers, as suggested by both an exploratory fMRI analysis and a follow-up case study with a patient with bilateral amygdala damage. Taken together, these results suggest that learning about potential monetary losses may depend on reinforcement learning related systems, rather than on typical structures involved in more biologically based

The content of lexical stimuli and self-reported physiological state modulate error-related negativity amplitude.

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Benau, Erik M; Moelter, Stephen T

2016-09-01

The Error-Related Negativity (ERN) and Correct-Response Negativity (CRN) are brief event-related potential (ERP) components-elicited after the commission of a response-associated with motivation, emotion, and affect. The Error Positivity (Pe) typically appears after the ERN, and corresponds to awareness of having committed an error. Although motivation has long been established as an important factor in the expression and morphology of the ERN, physiological state has rarely been explored as a variable in these investigations. In the present study, we investigated whether self-reported physiological state (SRPS; wakefulness, hunger, or thirst) corresponds with ERN amplitude and type of lexical stimuli. Participants completed a SRPS questionnaire and then completed a speeded Lexical Decision Task with words and pseudowords that were either food-related or neutral. Though similar in frequency and length, food-related stimuli elicited increased accuracy, faster errors, and generated a larger ERN and smaller CRN than neutral words. Self-reported thirst correlated with improved accuracy and smaller ERN and CRN amplitudes. The Pe and Pc (correct positivity) were not impacted by physiological state or by stimulus content. The results indicate that physiological state and manipulations of lexical content may serve as important avenues for future research. Future studies that apply more sensitive measures of physiological and motivational state (e.g., biomarkers for satiety) or direct manipulations of satiety may be a useful technique for future research into response monitoring. Copyright © 2016 Elsevier Inc. All rights reserved.

Differential autoshaping to common and distinctive elements of positive and negative discriminative stimuli.

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Wasserman, E A; Anderson, P A

1974-11-01

The learning by hungry pigeons of a discrimination between two successively presented compound visual stimuli was investigated using a two-key autoshaping procedure. Common and distinctive stimulus elements were simultaneously presented on separate keys and either followed by food delivery, S+, or not, S-. The subjects acquired both between-trial and within-trial discriminations. On S+ trials, pigeons pecked the distinctive stimulus more than the common stimulus; before responding ceased on S- trials, they pecked the common stimulus more than the distinctive one. Mastery of the within-display discrimination during S+ trials preceded mastery of the between-trials discrimination. These findings extend the Jenkins-Sainsbury analysis of discriminations based upon a single distinguishing feature to discriminations in which common and distinctive elements are associated with both the positive and negative discriminative stimuli. The similarity of these findings to other effects found in autoshaping-approach to signals that forecast reinforcement and withdrawal from signals that forecast nonreinforcement-is also discussed.

Responding for sucrose and wheel-running reinforcement: effect of body weight manipulation.

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Belke, Terry W

2004-02-27

As body weight increases, the excitatory strength of a stimulus signaling an opportunity to run should weaken to a greater degree than that of a stimulus signaling an opportunity to eat. To test this hypothesis, six male albino Wistar rats were placed in running wheels and exposed to a fixed interval 30-s schedule that produced either a drop of 15% sucrose solution or the opportunity to run for 15s as reinforcing consequences for lever pressing. Each reinforcer type was signaled by a different stimulus. The effect of varying body weight on responding maintained by these two reinforcers was investigated by systematically increasing and decreasing post-session food amounts. The initial body weight was 335 g. Body weights were increased to approximately 445 g and subsequently returned to 335 g. As body weight increased, overall and local lever-pressing rates decreased while post-reinforcement pauses lengthened. Analysis of post-reinforcement pauses and local lever-pressing rates in terms of transitions between successive reinforcers revealed that local response rates in the presence of stimuli signaling upcoming wheel and sucrose reinforcers were similarly affected. However, pausing in the presence of the stimulus signaling a wheel-running reinforcer lengthened to a greater extent than did pausing in the presence of the stimulus signaling sucrose. This result suggests that as body weight approaches ad-lib levels, the likelihood of initiation of responding to obtain an opportunity to run approaches zero and the animal "rejects" the opportunity to run in a manner similar to the rejection of less preferred food items in studies of food selectivity.

Assessing appetitive, aversive, and negative ethanol-mediated reinforcement through an immature rat model.

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Pautassi, Ricardo M; Nizhnikov, Michael E; Spear, Norman E

2009-06-01

The motivational effects of drugs play a key role during the transition from casual use to abuse and dependence. Ethanol reinforcement has been successfully studied through Pavlovian and operant conditioning in adult rats and mice genetically selected for their ready acceptance of ethanol. Another model for studying ethanol reinforcement is the immature (preweanling) rat, which consumes ethanol and exhibits the capacity to process tactile, odor and taste cues and transfer information between different sensorial modalities. This review describes the motivational effects of ethanol in preweanling, heterogeneous non-selected rats. Preweanlings exhibit ethanol-mediated conditioned taste avoidance and conditioned place aversion. Ethanol's appetitive effects, however, are evident when using first- and second-order conditioning and operant procedures. Ethanol also devalues the motivational representation of aversive stimuli, suggesting early negative reinforcement. It seems that preweanlings are highly sensitive not only to the aversive motivational effects of ethanol but also to its positive and negative (anti-anxiety) reinforcement potential. The review underscores the advantages of using a developing rat to evaluate alcohol's motivational effects.

Functional Alterations of Postcentral Gyrus Modulated by Angry Facial Expressions during Intraoral Tactile Stimuli in Patients with Burning Mouth Syndrome: A Functional Magnetic Resonance Imaging Study

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Yoshino, Atsuo; Okamoto, Yasumasa; Doi, Mitsuru; Okada, Go; Takamura, Masahiro; Ichikawa, Naho; Yamawaki, Shigeto

2017-01-01

Previous findings suggest that negative emotions could influence abnormal sensory perception in burning mouth syndrome (BMS). However, few studies have investigated the underlying neural mechanisms associated with BMS. We examined activation of brain regions in response to intraoral tactile stimuli when modulated by angry facial expressions. We performed functional magnetic resonance imaging on a group of 27 BMS patients and 21 age-matched healthy controls. Tactile stimuli were presented during different emotional contexts, which were induced via the continuous presentation of angry or neutral pictures of human faces. BMS patients exhibited higher tactile ratings and greater activation in the postcentral gyrus during the presentation of tactile stimuli involving angry faces relative to controls. Significant positive correlations between changes in brain activation elicited by angry facial images in the postcentral gyrus and changes in tactile rating scores by angry facial images were found for both groups. For BMS patients, there was a significant positive correlation between changes in tactile-related activation of the postcentral gyrus elicited by angry facial expressions and pain intensity in daily life. Findings suggest that neural responses in the postcentral gyrus are more strongly affected by angry facial expressions in BMS patients, which may reflect one possible mechanism underlying impaired somatosensory system function in this disorder. PMID:29163243

Functional Alterations of Postcentral Gyrus Modulated by Angry Facial Expressions during Intraoral Tactile Stimuli in Patients with Burning Mouth Syndrome: A Functional Magnetic Resonance Imaging Study

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Atsuo Yoshino

2017-11-01

Full Text Available Previous findings suggest that negative emotions could influence abnormal sensory perception in burning mouth syndrome (BMS. However, few studies have investigated the underlying neural mechanisms associated with BMS. We examined activation of brain regions in response to intraoral tactile stimuli when modulated by angry facial expressions. We performed functional magnetic resonance imaging on a group of 27 BMS patients and 21 age-matched healthy controls. Tactile stimuli were presented during different emotional contexts, which were induced via the continuous presentation of angry or neutral pictures of human faces. BMS patients exhibited higher tactile ratings and greater activation in the postcentral gyrus during the presentation of tactile stimuli involving angry faces relative to controls. Significant positive correlations between changes in brain activation elicited by angry facial images in the postcentral gyrus and changes in tactile rating scores by angry facial images were found for both groups. For BMS patients, there was a significant positive correlation between changes in tactile-related activation of the postcentral gyrus elicited by angry facial expressions and pain intensity in daily life. Findings suggest that neural responses in the postcentral gyrus are more strongly affected by angry facial expressions in BMS patients, which may reflect one possible mechanism underlying impaired somatosensory system function in this disorder.

High-Caloric and Chocolate Stimuli Processing in Healthy Humans: An Integration of Functional Imaging and Electrophysiological Findings

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Deyar Asmaro

2014-01-01

Full Text Available There has been a great deal of interest in understanding how the human brain processes appetitive food cues, and knowing how such cues elicit craving responses is particularly relevant when current eating behavior trends within Westernized societies are considered. One substance that holds a special place with regard to food preference is chocolate, and studies that used functional magnetic resonance imaging (fMRI and event-related potentials (ERPs have identified neural regions and electrical signatures that are elicited by chocolate cue presentations. This review will examine fMRI and ERP findings from studies that used high-caloric food and chocolate cues as stimuli, with a focus on responses observed in samples of healthy participants, as opposed to those with eating-related pathology. The utility of using high-caloric and chocolate stimuli as a means of understanding the human reward system will also be highlighted, as these findings may be particularly important for understanding processes related to pathological overeating and addiction to illicit substances. Finally, research from our own lab that focused on chocolate stimulus processing in chocolate cravers and non-cravers will be discussed, as the approach used may help bridge fMRI and ERP findings so that a more complete understanding of appetitive stimulus processing in the temporal and spatial domains may be established.

High-Caloric and Chocolate Stimuli Processing in Healthy Humans: An Integration of Functional Imaging and Electrophysiological Findings

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Asmaro, Deyar; Liotti, Mario

2014-01-01

There has been a great deal of interest in understanding how the human brain processes appetitive food cues, and knowing how such cues elicit craving responses is particularly relevant when current eating behavior trends within Westernized societies are considered. One substance that holds a special place with regard to food preference is chocolate, and studies that used functional magnetic resonance imaging (fMRI) and event-related potentials (ERPs) have identified neural regions and electrical signatures that are elicited by chocolate cue presentations. This review will examine fMRI and ERP findings from studies that used high-caloric food and chocolate cues as stimuli, with a focus on responses observed in samples of healthy participants, as opposed to those with eating-related pathology. The utility of using high-caloric and chocolate stimuli as a means of understanding the human reward system will also be highlighted, as these findings may be particularly important for understanding processes related to pathological overeating and addiction to illicit substances. Finally, research from our own lab that focused on chocolate stimulus processing in chocolate cravers and non-cravers will be discussed, as the approach used may help bridge fMRI and ERP findings so that a more complete understanding of appetitive stimulus processing in the temporal and spatial domains may be established. PMID:24434747

Severity of dependence modulates smokers' neuronal cue reactivity and cigarette craving elicited by tobacco advertisement.

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Vollstädt-Klein, Sabine; Kobiella, Andrea; Bühler, Mira; Graf, Caroline; Fehr, Christoph; Mann, Karl; Smolka, Michael N

2011-01-01

Smoking-related cues elicit craving and mesocorticolimbic brain activation in smokers. Severity of nicotine dependence seems to moderate cue reactivity, but the direction and mechanisms of its influence remains unclear. Although tobacco control policies demand a ban on tobacco advertising, cue reactivity studies in smokers so far have not employed tobacco advertisement as experimental stimuli. We investigated whether tobacco advertisement elicits cue reactivity at a behavioral (subjective craving) and a neural level (using functional magnetic resonance imaging) in 22 smokers and 21 never-smokers. Moreover, we studied the influence of severity of dependence on cue reactivity. In smokers, tobacco advertisement elicited substantially more craving than control advertisement whereas never-smokers reported no cue induced craving. Surprisingly, neuronal cue reactivity did not differ between smokers and never-smokers. Moderately dependent smokers' craving increased over the course of the experiment, whereas highly dependent smokers' craving was unaffected. Moderately dependent smokers' brain activity elicited by tobacco advertisement was higher in the amygdala, hippocampus, putamen and thalamus compared with highly dependent smokers. Furthermore, limbic brain activation predicted picture recognition rates after the scanning session, even in never-smokers. Our findings show that tobacco advertisement elicits cigarette craving and neuronal cue reactivity primarily in moderately dependent smokers, indicating that they might be particularly responsive towards external smoking-related cues. On the other hand, neuronal cue reactivity and cigarette craving in highly dependent smokers is more likely triggered by internal cues such as withdrawal symptoms. Tobacco advertisement seems to likewise appeal to smokers and non-smokers, clarifying the potential danger especially for young non-smokers. © 2010 The Authors, Addiction Biology © 2010 Society for the Study of Addiction.

Optimizing microstimulation using a reinforcement learning framework.

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Brockmeier, Austin J; Choi, John S; Distasio, Marcello M; Francis, Joseph T; Príncipe, José C

2011-01-01

The ability to provide sensory feedback is desired to enhance the functionality of neuroprosthetics. Somatosensory feedback provides closed-loop control to the motor system, which is lacking in feedforward neuroprosthetics. In the case of existing somatosensory function, a template of the natural response can be used as a template of desired response elicited by electrical microstimulation. In the case of no initial training data, microstimulation parameters that produce responses close to the template must be selected in an online manner. We propose using reinforcement learning as a framework to balance the exploration of the parameter space and the continued selection of promising parameters for further stimulation. This approach avoids an explicit model of the neural response from stimulation. We explore a preliminary architecture--treating the task as a k-armed bandit--using offline data recorded for natural touch and thalamic microstimulation, and we examine the methods efficiency in exploring the parameter space while concentrating on promising parameter forms. The best matching stimulation parameters, from k = 68 different forms, are selected by the reinforcement learning algorithm consistently after 334 realizations.

How does the adult attachment affect human’s recognition to love-related and sex-related stimuli: an ERP study

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Juan eHou

2016-05-01

Full Text Available In the present study, we investigated the relationship among three emotion-motivation systems (adult attachment, romantic love and sex. We recorded Event-related potentials (ERPs in 37 healthy volunteers who had experienced romantic love while they viewed SEX, LOVE, FRIEND, SPORT and NEUTRAL images. We also measured adult attachment styles, level of passionate love and sexual attitudes. As expected, results showed that, firstly, response to love-related image-stimuli and sex-related image-stimuli on the electrophysiological data significantly different on N1, N2 and PSW components. Secondly, the different adult attachment styles affected individuals’ recognition processing in response to love-related and sex-related images, especially, to sex-related images. Further analysis showed that voltages elicited by fearful attachment style individuals were significantly lower than voltages elicited by secure and dismissing attachment style individuals on sex-related images at frontal sites, on N1 and N2 components. Thirdly, from behavior data, we found that adult attachment styles were not significantly related to any dimension of sexual attitudes but were significantly related to passionate love scale total points. Thus, the behavior results were not in line with the electrophysiological results. The present study proved that adult attachment styles might mediate individuals’ lust and attraction systems.

False memories to emotional stimuli are not equally affected in right- and left-brain-damaged stroke patients.

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Buratto, Luciano Grüdtner; Zimmermann, Nicolle; Ferré, Perrine; Joanette, Yves; Fonseca, Rochele Paz; Stein, Lilian Milnitsky

2014-10-01

Previous research has attributed to the right hemisphere (RH) a key role in eliciting false memories to visual emotional stimuli. These results have been explained in terms of two right-hemisphere properties: (i) that emotional stimuli are preferentially processed in the RH and (ii) that visual stimuli are represented more coarsely in the RH. According to this account, false emotional memories are preferentially produced in the RH because emotional stimuli are both more strongly and more diffusely activated during encoding, leaving a memory trace that can be erroneously reactivated by similar but unstudied emotional items at test. If this right-hemisphere hypothesis is correct, then RH damage should result in a reduction in false memories to emotional stimuli relative to left-hemisphere lesions. To investigate this possibility, groups of right-brain-damaged (RBD, N=15), left-brain-damaged (LBD, N=15) and healthy (HC, N=30) participants took part in a recognition memory experiment with emotional (negative and positive) and non-emotional pictures. False memories were operationalized as incorrect responses to unstudied pictures that were similar to studied ones. Both RBD and LBD participants showed similar reductions in false memories for negative pictures relative to controls. For positive pictures, however, false memories were reduced only in RBD patients. The results provide only partial support for the right-hemisphere hypothesis and suggest that inter-hemispheric cooperation models may be necessary to fully account for false emotional memories. Copyright © 2014 Elsevier Inc. All rights reserved.

Visual sexual stimuli – cue or reward? A key for interpreting brain imaging studies on human sexual behaviors

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Mateusz Gola

2016-08-01

Full Text Available There is an increasing number of neuroimaging studies using visual sexual stimuli (VSS for human sexuality studies, including emerging field of research on compulsive sexual behaviors. A central question in this field is whether behaviors such as extensive pornography consumption share common brain mechanisms with widely studied substance and behavioral addictions. Depending on how VSS are conceptualized, different predictions can be formulated within the frameworks of Reinforcement Learning or Incentive Salience Theory, where a crucial distinction is made between conditioned (cue and unconditioned (reward stimuli (related to reward anticipation vs reward consumption, respectively. Surveying 40 recent human neuroimaging studies we show existing ambiguity about the conceptualization of VSS. Therefore, we feel that it is important to address the question of whether VSS should be considered as cues (conditioned stimuli or rewards (unconditioned stimuli. Here we present our own perspective, which is that in most laboratory settings VSS play a role of reward (unconditioned stimuli, as evidenced by: 1. experience of pleasure while watching VSS, possibly accompanied by genital reaction 2. reward-related brain activity correlated with these pleasurable feelings in response to VSS, 3. a willingness to exert effort to view VSS similarly as for other rewarding stimuli such as money, and/or 4. conditioning for cues (CS predictive for. We hope that this perspective paper will initiate a scientific discussion on this important and overlooked topic and increase attention for appropriate interpretations of results of human neuroimaging studies using VSS.

An online brain-computer interface based on shifting attention to concurrent streams of auditory stimuli

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Hill, N. J.; Schölkopf, B.

2012-04-01

We report on the development and online testing of an electroencephalogram-based brain-computer interface (BCI) that aims to be usable by completely paralysed users—for whom visual or motor-system-based BCIs may not be suitable, and among whom reports of successful BCI use have so far been very rare. The current approach exploits covert shifts of attention to auditory stimuli in a dichotic-listening stimulus design. To compare the efficacy of event-related potentials (ERPs) and steady-state auditory evoked potentials (SSAEPs), the stimuli were designed such that they elicited both ERPs and SSAEPs simultaneously. Trial-by-trial feedback was provided online, based on subjects' modulation of N1 and P3 ERP components measured during single 5 s stimulation intervals. All 13 healthy subjects were able to use the BCI, with performance in a binary left/right choice task ranging from 75% to 96% correct across subjects (mean 85%). BCI classification was based on the contrast between stimuli in the attended stream and stimuli in the unattended stream, making use of every stimulus, rather than contrasting frequent standard and rare ‘oddball’ stimuli. SSAEPs were assessed offline: for all subjects, spectral components at the two exactly known modulation frequencies allowed discrimination of pre-stimulus from stimulus intervals, and of left-only stimuli from right-only stimuli when one side of the dichotic stimulus pair was muted. However, attention modulation of SSAEPs was not sufficient for single-trial BCI communication, even when the subject's attention was clearly focused well enough to allow classification of the same trials via ERPs. ERPs clearly provided a superior basis for BCI. The ERP results are a promising step towards the development of a simple-to-use, reliable yes/no communication system for users in the most severely paralysed states, as well as potential attention-monitoring and -training applications outside the context of assistive technology.

An online brain-computer interface based on shifting attention to concurrent streams of auditory stimuli

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Hill, N J; Schölkopf, B

2012-01-01

We report on the development and online testing of an EEG-based brain-computer interface (BCI) that aims to be usable by completely paralysed users—for whom visual or motor-system-based BCIs may not be suitable, and among whom reports of successful BCI use have so far been very rare. The current approach exploits covert shifts of attention to auditory stimuli in a dichotic-listening stimulus design. To compare the efficacy of event-related potentials (ERPs) and steady-state auditory evoked potentials (SSAEPs), the stimuli were designed such that they elicited both ERPs and SSAEPs simultaneously. Trial-by-trial feedback was provided online, based on subjects’ modulation of N1 and P3 ERP components measured during single 5-second stimulation intervals. All 13 healthy subjects were able to use the BCI, with performance in a binary left/right choice task ranging from 75% to 96% correct across subjects (mean 85%). BCI classification was based on the contrast between stimuli in the attended stream and stimuli in the unattended stream, making use of every stimulus, rather than contrasting frequent standard and rare “oddball” stimuli. SSAEPs were assessed offline: for all subjects, spectral components at the two exactly-known modulation frequencies allowed discrimination of pre-stimulus from stimulus intervals, and of left-only stimuli from right-only stimuli when one side of the dichotic stimulus pair was muted. However, attention-modulation of SSAEPs was not sufficient for single-trial BCI communication, even when the subject’s attention was clearly focused well enough to allow classification of the same trials via ERPs. ERPs clearly provided a superior basis for BCI. The ERP results are a promising step towards the development of a simple-to-use, reliable yes/no communication system for users in the most severely paralysed states, as well as potential attention-monitoring and -training applications outside the context of assistive technology. PMID:22333135

Suppression of bulboreticular unit responses to noxious stimuli by analgesic mesencephalic stimulation.

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Morrow, T J; Casey, K L

1983-01-01

The responses of 302 neurons in the medial medullary reticular formation (MRF) to a variety of noxious and innocuous somatic stimuli were studied in anesthetized and awake rats. In addition, the effects of analgesic electrical stimulation in the mesencephalon (MES) on unit responses were examined. Tail shock was the most effective stimulus, exciting more than 80% of all units recorded. This stimulus was considered separately during data analysis, since it could not be classified as noxious or innocuous. Noxious somatic stimuli (including pinch, firm pressure, pin prick, and radiant heating of the tail above 45 degrees C were especially effective in eliciting discharge in a significant fraction of all cells in both awake (123/205) and anesthetized (45/97) animals. Nociceptive neurons could be classified as nociceptive specific (NS) or wide dynamic range (WDR) depending on their responses to all somatic stimuli tested. Nociceptive neurons showed no preferential anatomical distribution. Most neurons, including those responsive to noxious inputs, exhibited large, often bilateral receptive fields which frequently covered the tail, one or more limbs, and extensive areas of the body or head. Electrical stimulation within or adjacent to the mesencephalic periaqueductal gray matter depressed the spontaneous and evoked discharge of MRF neurons in both acute and chronic preparations. This inhibition showed a significant preference (p less than 0.001, chi-square statistic) for units that were excited by somatic and especially noxious stimuli. No units were facilitated by MES stimulation. In the awake rat, unit suppression closely followed the time course and level of MES-induced analgesia. Excitability data from the acute experiments suggest that this response inhibition may be the result of a direct action on MRF neurons. Anesthesia severely depressed the spontaneous discharge of MRF neurons as well as the activity evoked by innocuous somatic stimulation. Our data suggest

Unconscious neural processing differs with method used to render stimuli invisible

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Sergey Victor Fogelson

2014-06-01

Full Text Available Visual stimuli can be kept from awareness using various methods. The extent of processing that a given stimulus receives in the absence of awareness is typically used to make claims about the role of consciousness more generally. The neural processing elicited by a stimulus, however, may also depend on the method used to keep it from awareness, and not only on whether the stimulus reaches awareness. Here we report that the method used to render an image invisible has a dramatic effect on how category information about the unseen stimulus is encoded across the human brain. We collected fMRI data while subjects viewed images of faces and tools, that were rendered invisible using either continuous flash suppression (CFS or chromatic flicker fusion (CFF. In a third condition, we presented the same images under normal fully visible viewing conditions. We found that category information about visible images could be extracted from patterns of fMRI responses throughout areas of neocortex known to be involved in face or tool processing. However, category information about stimuli kept from awareness using CFS could be recovered exclusively within occipital cortex, whereas information about stimuli kept from awareness using CFF was also decodable within temporal and frontal regions. We conclude that unconsciously presented objects are processed differently depending on how they are rendered subjectively invisible. Caution should therefore be used in making generalizations on the basis of any one method about the neural basis of consciousness or the extent of information processing without consciousness.

Unconscious neural processing differs with method used to render stimuli invisible.

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Fogelson, Sergey V; Kohler, Peter J; Miller, Kevin J; Granger, Richard; Tse, Peter U

2014-01-01

Visual stimuli can be kept from awareness using various methods. The extent of processing that a given stimulus receives in the absence of awareness is typically used to make claims about the role of consciousness more generally. The neural processing elicited by a stimulus, however, may also depend on the method used to keep it from awareness, and not only on whether the stimulus reaches awareness. Here we report that the method used to render an image invisible has a dramatic effect on how category information about the unseen stimulus is encoded across the human brain. We collected fMRI data while subjects viewed images of faces and tools, that were rendered invisible using either continuous flash suppression (CFS) or chromatic flicker fusion (CFF). In a third condition, we presented the same images under normal fully visible viewing conditions. We found that category information about visible images could be extracted from patterns of fMRI responses throughout areas of neocortex known to be involved in face or tool processing. However, category information about stimuli kept from awareness using CFS could be recovered exclusively within occipital cortex, whereas information about stimuli kept from awareness using CFF was also decodable within temporal and frontal regions. We conclude that unconsciously presented objects are processed differently depending on how they are rendered subjectively invisible. Caution should therefore be used in making generalizations on the basis of any one method about the neural basis of consciousness or the extent of information processing without consciousness.

Differential autoshaping to common and distinctive elements of positive and negative discriminative stimuli1

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Wasserman, Edward A.; Anderson, Patricia A.

1974-01-01

The learning by hungry pigeons of a discrimination between two successively presented compound visual stimuli was investigated using a two-key autoshaping procedure. Common and distinctive stimulus elements were simultaneously presented on separate keys and either followed by food delivery, S+, or not, S−. The subjects acquired both between-trial and within-trial discriminations. On S+ trials, pigeons pecked the distinctive stimulus more than the common stimulus; before responding ceased on S− trials, they pecked the common stimulus more than the distinctive one. Mastery of the within-display discrimination during S+ trials preceded mastery of the between-trials discrimination. These findings extend the Jenkins-Sainsbury analysis of discriminations based upon a single distinguishing feature to discriminations in which common and distinctive elements are associated with both the positive and negative discriminative stimuli. The similarity of these findings to other effects found in autoshaping—approach to signals that forecast reinforcement and withdrawal from signals that forecast nonreinforcement—is also discussed. PMID:16811812

Open Source Tools for Temporally Controlled Rodent Behavior Suitable for Electrophysiology and Optogenetic Manipulations

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Nicola Solari

2018-05-01

Full Text Available Understanding how the brain controls behavior requires observing and manipulating neural activity in awake behaving animals. Neuronal firing is timed at millisecond precision. Therefore, to decipher temporal coding, it is necessary to monitor and control animal behavior at the same level of temporal accuracy. However, it is technically challenging to deliver sensory stimuli and reinforcers as well as to read the behavioral responses they elicit with millisecond precision. Presently available commercial systems often excel in specific aspects of behavior control, but they do not provide a customizable environment allowing flexible experimental design while maintaining high standards for temporal control necessary for interpreting neuronal activity. Moreover, delay measurements of stimulus and reinforcement delivery are largely unavailable. We combined microcontroller-based behavior control with a sound delivery system for playing complex acoustic stimuli, fast solenoid valves for precisely timed reinforcement delivery and a custom-built sound attenuated chamber using high-end industrial insulation materials. Together this setup provides a physical environment to train head-fixed animals, enables calibrated sound stimuli and precisely timed fluid and air puff presentation as reinforcers. We provide latency measurements for stimulus and reinforcement delivery and an algorithm to perform such measurements on other behavior control systems. Combined with electrophysiology and optogenetic manipulations, the millisecond timing accuracy will help interpret temporally precise neural signals and behavioral changes. Additionally, since software and hardware provided here can be readily customized to achieve a large variety of paradigms, these solutions enable an unusually flexible design of rodent behavioral experiments.

Open Source Tools for Temporally Controlled Rodent Behavior Suitable for Electrophysiology and Optogenetic Manipulations.

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Solari, Nicola; Sviatkó, Katalin; Laszlovszky, Tamás; Hegedüs, Panna; Hangya, Balázs

2018-01-01

Understanding how the brain controls behavior requires observing and manipulating neural activity in awake behaving animals. Neuronal firing is timed at millisecond precision. Therefore, to decipher temporal coding, it is necessary to monitor and control animal behavior at the same level of temporal accuracy. However, it is technically challenging to deliver sensory stimuli and reinforcers as well as to read the behavioral responses they elicit with millisecond precision. Presently available commercial systems often excel in specific aspects of behavior control, but they do not provide a customizable environment allowing flexible experimental design while maintaining high standards for temporal control necessary for interpreting neuronal activity. Moreover, delay measurements of stimulus and reinforcement delivery are largely unavailable. We combined microcontroller-based behavior control with a sound delivery system for playing complex acoustic stimuli, fast solenoid valves for precisely timed reinforcement delivery and a custom-built sound attenuated chamber using high-end industrial insulation materials. Together this setup provides a physical environment to train head-fixed animals, enables calibrated sound stimuli and precisely timed fluid and air puff presentation as reinforcers. We provide latency measurements for stimulus and reinforcement delivery and an algorithm to perform such measurements on other behavior control systems. Combined with electrophysiology and optogenetic manipulations, the millisecond timing accuracy will help interpret temporally precise neural signals and behavioral changes. Additionally, since software and hardware provided here can be readily customized to achieve a large variety of paradigms, these solutions enable an unusually flexible design of rodent behavioral experiments.

Caffeine increases the motivation to obtain non-drug reinforcers in rats

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Sheppard, A. Brianna; Gross, Skyler C.; Pavelka, Sarah A.; Hall, Melanie J.; Palmatier, Matthew I.

2012-01-01

BACKGROUND Caffeine is widely considered to be a reinforcer in humans, but this effect is difficult to measure in non-human animals. We hypothesized that caffeine may have dual reinforcing effects comparable to nicotine - limited primary reinforcing effects, but potent reinforcement enhancing effects. The present studies tested this hypothesis by investigating the effect of caffeine on responding for non-drug rewards. METHODS In two experiments, rats were shaped to respond on a progressive ratio (PR) schedule for sucrose solution (20% w/v; Experiment 1) or a fixed ratio 2 (FR2) schedule for a moderately reinforcing visual stimulus (VS; Experiment 2). Pretreatment with various doses of caffeine (0–50 mg/kg, intraperitoneal injection) were administered prior to tests over successive week days (M-F). In Experiment 1, acute administration of low-moderate caffeine doses (6.25–25 mg/kg) increased responding for sucrose under the PR schedule. This effect of caffeine declined over the initial 15 test days. In Experiment 2, only acute pretreatment with 12.5 mg/kg caffeine increased responding for the visual stimulus and complete tolerance to this effect of caffeine was observed over the 15 days of testing. In follow up tests we found that abstinence periods of 4 and 8 days resulted in incomplete recovery of the enhancing effects of caffeine. CONCLUSION The findings suggest that caffeine enhances the reinforcing effects of non-drug stimuli, but that the pharmacological profile of these effects may differ from other psychomotor stimulants. PMID:22336397

Switching neuronal state: optimal stimuli revealed using a stochastically-seeded gradient algorithm.

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Chang, Joshua; Paydarfar, David

2014-12-01

Inducing a switch in neuronal state using energy optimal stimuli is relevant to a variety of problems in neuroscience. Analytical techniques from optimal control theory can identify such stimuli; however, solutions to the optimization problem using indirect variational approaches can be elusive in models that describe neuronal behavior. Here we develop and apply a direct gradient-based optimization algorithm to find stimulus waveforms that elicit a change in neuronal state while minimizing energy usage. We analyze standard models of neuronal behavior, the Hodgkin-Huxley and FitzHugh-Nagumo models, to show that the gradient-based algorithm: (1) enables automated exploration of a wide solution space, using stochastically generated initial waveforms that converge to multiple locally optimal solutions; and (2) finds optimal stimulus waveforms that achieve a physiological outcome condition, without a priori knowledge of the optimal terminal condition of all state variables. Analysis of biological systems using stochastically-seeded gradient methods can reveal salient dynamical mechanisms underlying the optimal control of system behavior. The gradient algorithm may also have practical applications in future work, for example, finding energy optimal waveforms for therapeutic neural stimulation that minimizes power usage and diminishes off-target effects and damage to neighboring tissue.

Conditioned Stimuli’s Role in Relapse: Pre-Clinical Research on Pavlovian Instrumental Transfer

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Lamb, R.J.; Schindler, W.; Pinkston, Jonathan W.

2016-01-01

Rationale and Objective Pavlovian learning is central to many theories of addiction. In these theories, stimuli paired with drug ingestion become Conditioned Stimuli (CS) and subsequently elicit drug-seeking and -taking. However in most relevant studies, Pavlovian and instrumental learning are confounded. This confound may be avoided in Pavlovian-Instrumental-Transfer (PIT) procedures. In PIT, Pavlovian and instrumental learning are established separately, and then combined. In order to better understand the role of CSs in addiction, we review the relevant studies using PIT. Findings We identified seven articles examining PIT effects of ethanol- or cocaine-paired CSs. Under at least one condition six of these articles reported CS-elicited increases in responding previously maintained by drug. However, the only study using the optimal control condition failed to find a CS-elicited increase. Two studies examining CS specificity found the CS also increased responding maintained by a different reinforcer. Two studies examined if CSs elicit increases in actual drug-taking. Both failed to find CS-elicited increases, i.e., no study shows CS-elicited increases in actual drug-taking. Further, CS-elicited increases in extinguished responding are short-lived. Conclusions These findings are not entirely consistent with Pavlovian learning playing a central role in addiction. However, design issues can explain most of these inconsistencies. Studies without these design issues are needed. Additionally, existing theories hypothesize drug-paired CSs increase drug-taking by increasing motivation, by eliciting conditioned responses that make drug-seeking more probable, or by a combination of these. Work distinguishing between these mechanisms would also be useful. PMID:26800688

Visual Sexual Stimuli-Cue or Reward? A Perspective for Interpreting Brain Imaging Findings on Human Sexual Behaviors.

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Gola, Mateusz; Wordecha, Małgorzata; Marchewka, Artur; Sescousse, Guillaume

2016-01-01

There is an increasing number of neuroimaging studies using visual sexual stimuli (VSS), especially within the emerging field of research on compulsive sexual behaviors (CSB). A central question in this field is whether behaviors such as excessive pornography consumption share common brain mechanisms with widely studied substance and behavioral addictions. Depending on how VSS are conceptualized, different predictions can be formulated within the frameworks of Reinforcement Learning or Incentive Salience Theory, where a crucial distinction is made between conditioned and unconditioned stimuli (related to reward anticipation vs. reward consumption, respectively). Surveying 40 recent human neuroimaging studies we show existing ambiguity about the conceptualization of VSS. Therefore, we feel that it is important to address the question of whether VSS should be considered as conditioned stimuli (cue) or unconditioned stimuli (reward). Here we present our own perspective, which is that in most laboratory settings VSS play a role of reward, as evidenced by: (1) experience of pleasure while watching VSS, possibly accompanied by genital reaction; (2) reward-related brain activity correlated with these pleasurable feelings in response to VSS; (3) a willingness to exert effort to view VSS similarly as for other rewarding stimuli such as money; and (4) conditioning for cues predictive of VSS. We hope that this perspective article will initiate a scientific discussion on this important and overlooked topic and increase attention for appropriate interpretations of results of human neuroimaging studies using VSS.

How we learn to make decisions: rapid propagation of reinforcement learning prediction errors in humans.

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Krigolson, Olav E; Hassall, Cameron D; Handy, Todd C

2014-03-01

Our ability to make decisions is predicated upon our knowledge of the outcomes of the actions available to us. Reinforcement learning theory posits that actions followed by a reward or punishment acquire value through the computation of prediction errors-discrepancies between the predicted and the actual reward. A multitude of neuroimaging studies have demonstrated that rewards and punishments evoke neural responses that appear to reflect reinforcement learning prediction errors [e.g., Krigolson, O. E., Pierce, L. J., Holroyd, C. B., & Tanaka, J. W. Learning to become an expert: Reinforcement learning and the acquisition of perceptual expertise. Journal of Cognitive Neuroscience, 21, 1833-1840, 2009; Bayer, H. M., & Glimcher, P. W. Midbrain dopamine neurons encode a quantitative reward prediction error signal. Neuron, 47, 129-141, 2005; O'Doherty, J. P. Reward representations and reward-related learning in the human brain: Insights from neuroimaging. Current Opinion in Neurobiology, 14, 769-776, 2004; Holroyd, C. B., & Coles, M. G. H. The neural basis of human error processing: Reinforcement learning, dopamine, and the error-related negativity. Psychological Review, 109, 679-709, 2002]. Here, we used the brain ERP technique to demonstrate that not only do rewards elicit a neural response akin to a prediction error but also that this signal rapidly diminished and propagated to the time of choice presentation with learning. Specifically, in a simple, learnable gambling task, we show that novel rewards elicited a feedback error-related negativity that rapidly decreased in amplitude with learning. Furthermore, we demonstrate the existence of a reward positivity at choice presentation, a previously unreported ERP component that has a similar timing and topography as the feedback error-related negativity that increased in amplitude with learning. The pattern of results we observed mirrored the output of a computational model that we implemented to compute reward

The influence of pain-related expectations on intensity perception of non-painful somatosensory stimuli.

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Zaman, Jonas; Wiech, Katja; Claes, Nathalie; Van Oudenhove, Lukas; Van Diest, Ilse; Vlaeyen, Johan W S

2018-04-03

The extent to which pain-related expectations, known to affect pain perception, also affect perception of non-painful sensations remains unclear, as well as the potential role of unpredictability in this context. In a proprioceptive fear conditioning paradigm, various arm extension movements were associated with predictable and unpredictable electrocutaneous pain or its absence. During a subsequent test phase non-painful electrocutaneous stimuli with a high or low intensity were presented during movement execution. We used hierarchical drift diffusion modeling to examine the influence of expecting pain on the perceptual decision-making process underlying intensity perception of non-painful sensations. In the first experiment (n=36), the pain stimulus was never presented during the test phase after conditioning. In the second experiment (n=39), partial reinforcement was adopted to prevent extinction of pain expectations. In both experiments, movements that were associated with (un)predictable pain led to higher pain-expectancy, self-reported fear, unpleasantness and arousal, as compared to movements that were never paired with pain (effect sizes ηp ranging from .119 - .557; all p-values threat of the pain US remained present - we found that the expectation of pain affected decision-making. Compared to the no pain condition, an a priori decision-making bias towards the high intensity decision threshold was found with the strongest bias during unpredictable pain (effect sizes ηp ranging from .469 - .504; all p-values affects inferential processes for subsequent painful but also for non-painful bodily stimuli, with unpredictability moderating these effects, and only when the threat of pain remains present due to partial reinforcement.

Computer-animated stimuli to measure motion sensitivity: constraints on signal design in the Jacky dragon.

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Woo, Kevin L; Rieucau, Guillaume; Burke, Darren

2017-02-01

Identifying perceptual thresholds is critical for understanding the mechanisms that underlie signal evolution. Using computer-animated stimuli, we examined visual speed sensitivity in the Jacky dragon Amphibolurus muricatus , a species that makes extensive use of rapid motor patterns in social communication. First, focal lizards were tested in discrimination trials using random-dot kinematograms displaying combinations of speed, coherence, and direction. Second, we measured subject lizards' ability to predict the appearance of a secondary reinforcer (1 of 3 different computer-generated animations of invertebrates: cricket, spider, and mite) based on the direction of movement of a field of drifting dots by following a set of behavioural responses (e.g., orienting response, latency to respond) to our virtual stimuli. We found an effect of both speed and coherence, as well as an interaction between these 2 factors on the perception of moving stimuli. Overall, our results showed that Jacky dragons have acute sensitivity to high speeds. We then employed an optic flow analysis to match the performance to ecologically relevant motion. Our results suggest that the Jacky dragon visual system may have been shaped to detect fast motion. This pre-existing sensitivity may have constrained the evolution of conspecific displays. In contrast, Jacky dragons may have difficulty in detecting the movement of ambush predators, such as snakes and of some invertebrate prey. Our study also demonstrates the potential of the computer-animated stimuli technique for conducting nonintrusive tests to explore motion range and sensitivity in a visually mediated species.

Nogo stimuli do not receive more attentional suppression or response inhibition than neutral stimuli: evidence from the N2pc, PD and N2 components in a spatial cueing paradigm

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Caroline eBarras

2016-05-01

Full Text Available It has been claimed that stimuli sharing the color of the nogo-target are suppressed because of the strong incentive to not process the nogo-target, but we failed to replicate this finding. Participants searched for a color singleton in the target display and indicated its shape when it was in the go color. If the color singleton in the target display was in the nogo color, they had to withhold the response. The target display was preceded by a cue display that also contained a color singleton (the cue. The cue was either in the color of the go or nogo target, or it was in an unrelated, neutral color. With cues in the go color, reaction times (RTs were shorter when the cue appeared at the same location as the target compared to when it appeared at a different location. Also, electrophysiological recordings showed that an index of attentional selection, the N2pc, was elicited by go cues. Surprisingly, we failed to replicate cueing costs for cues in the nogo color that were originally reported by Anderson and Folk (2012. Consistently, we also failed to find an electrophysiological index of attentional suppression (the PD for cues in the nogo color. Further, fronto-central ERPs to the cue display showed the same negativity for nogo and neutral stimuli relative to go stimuli, which is at odds with response inhibition and conflict monitoring accounts of the Nogo-N2. Thus, the modified cueing paradigm employed here provides little evidence that features associated with nogo-targets are suppressed at the level of attention or response selection. Rather, nogo-stimuli are efficiently ignored and attention is focused on features that require a response.

Disrupted expected value signaling in youth with disruptive behavior disorders to environmental reinforcers.

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White, Stuart F; Fowler, Katherine A; Sinclair, Stephen; Schechter, Julia C; Majestic, Catherine M; Pine, Daniel S; Blair, R James

2014-05-01

Youth with disruptive behavior disorders (DBD), including conduct disorder (CD) and oppositional defiant disorder (ODD), have difficulties in reinforcement-based decision making, the neural basis of which is poorly understood. Studies examining decision making in youth with DBD have revealed reduced reward responses within the ventromedial prefrontal cortex/orbitofrontal cortex (vmPFC/OFC), increased responses to unexpected punishment within the vmPFC and striatum, and reduced use of expected value information in the anterior insula cortex and dorsal anterior cingulate cortex during the avoidance of suboptimal choices. Previous work has used only monetary reinforcement. The current study examined whether dysfunction in youth with DBD during decision making extended to environmental reinforcers. A total of 30 youth (15 healthy youth and 15 youth with DBD) completed a novel reinforcement-learning paradigm using environmental reinforcers (physical threat images, e.g., striking snake image; contamination threat images, e.g., rotting food; appetitive images, e.g., puppies) while undergoing functional magnetic resonance imaging (fMRI). Behaviorally, healthy youth were significantly more likely to avoid physical threat, but not contamination threat, stimuli than youth with DBD. Imaging results revealed that youth with DBD showed significantly reduced use of expected value information in the bilateral caudate, thalamus, and posterior cingulate cortex during the avoidance of suboptimal responses. The current data suggest that youth with DBD show deficits to environmental reinforcers similar to the deficits seen to monetary reinforcers. Importantly, this deficit was unrelated to callous-unemotional (CU) traits, suggesting that caudate impairment may be a common deficit across youth with DBD. Published by Elsevier Inc.

Immediate processing of erotic stimuli in paedophilia and controls: a case control study.

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Habermeyer, Benedikt; Esposito, Fabrizio; Händel, Nadja; Lemoine, Patrick; Klarhöfer, Markus; Mager, Ralph; Dittmann, Volker; Seifritz, Erich; Graf, Marc

2013-03-19

Most neuroimaging studies investigating sexual arousal in paedophilia used erotic pictures together with a blocked fMRI design and long stimulus presentation time. While this approach allows the detection of sexual arousal, it does not enable the assessment of the immediate processing of erotically salient stimuli. Our study aimed to identify neuronal networks related to the immediate processing of erotic stimuli in heterosexual male paedophiles and healthy age-matched controls. We presented erotic pictures of prepubescent children and adults in an event related fMRI-design to eight paedophilic subjects and age-matched controls. Erotic pictures of females elicited more activation in the right temporal lobe, the right parietal lobe and both occipital lobes and erotic pictures of children activated the right dorsomedial prefrontal cortex in both groups. An interaction of sex, age and group was present in the right anteriolateral oribitofrontal cortex. Our event related study design confirmed that erotic pictures activate some of the brain regions already known to be involved in the processing of erotic pictures when these are presented in blocks. In addition, it revealed that erotic pictures of prepubescent children activate brain regions critical for choosing response strategies in both groups, and that erotically salient stimuli selectively activate a brain region in paedophilic subjects that had previously been attributed to reward and punishment, and that had been shown to be implicated in the suppression of erotic response and deception.

Modification of sudden onset auditory ERP by involuntary attention to visual stimuli.

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Oray, Serkan; Lu, Zhong-Lin; Dawson, Michael E

2002-03-01

To investigate the cross-modal nature of the exogenous attention system, we studied how involuntary attention in the visual modality affects ERPs elicited by sudden onset of events in the auditory modality. Relatively loud auditory white noise bursts were presented to subjects with random and long inter-trial intervals. The noise bursts were either presented alone, or paired with a visual stimulus with a visual to auditory onset asynchrony of 120 ms. In a third condition, the visual stimuli were shown alone. All three conditions, auditory alone, visual alone, and paired visual/auditory, were randomly inter-mixed and presented with equal probabilities. Subjects were instructed to fixate on a point in front of them without task instructions concerning either the auditory or visual stimuli. ERPs were recorded from 28 scalp sites throughout every experimental session. Compared to ERPs in the auditory alone condition, pairing the auditory noise bursts with the visual stimulus reduced the amplitude of the auditory N100 component at Cz by 40% and the auditory P200/P300 component at Cz by 25%. No significant topographical change was observed in the scalp distributions of the N100 and P200/P300. Our results suggest that involuntary attention to visual stimuli suppresses early sensory (N100) as well as late cognitive (P200/P300) processing of sudden auditory events. The activation of the exogenous attention system by sudden auditory onset can be modified by involuntary visual attention in a cross-model, passive prepulse inhibition paradigm.

Perceiving, imaging, and preferring physiognomic stimuli.

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Lindauer, M S

1986-01-01

Physiognomic color responses in perception, imagery, and affect were investigated. Maluma and taketa, nonsense stimuli defined by many investigators as physiognomic, were utilized as prototypical physiognomic stimuli, along with eight other stimuli of various sorts. In Experiment 1, 22 subjects matched the colors of the stimuli; in Experiment 2, 27 subjects reported their imagery to the stimuli; and in Experiment 3, 16 subjects gave their color preferences for the stimuli. The Munsell sets of colors were employed throughout. Significant differences between the physiognomic and other stimuli were found on the brightness and saturation of color matches, images, and preferences. Other differences (e.g., the latency of color images) were also present. Distinctions were also noted between the two physiognomic stimuli. These results support the priority of innate and perceptual processes in physiognomy over those of learning and memory, although some ambiguities still remain.

Long-term memory of color stimuli in the jungle crow (Corvus macrorhynchos).

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Bogale, Bezawork Afework; Sugawara, Satoshi; Sakano, Katsuhisa; Tsuda, Sonoko; Sugita, Shoei

2012-03-01

Wild-caught jungle crows (n = 20) were trained to discriminate between color stimuli in a two-alternative discrimination task. Next, crows were tested for long-term memory after 1-, 2-, 3-, 6-, and 10-month retention intervals. This preliminary study showed that jungle crows learn the task and reach a discrimination criterion (80% or more correct choices in two consecutive sessions of ten trials) in a few trials, and some even in a single session. Most, if not all, crows successfully remembered the constantly reinforced visual stimulus during training after all retention intervals. These results suggest that jungle crows have a high retention capacity for learned information, at least after a 10-month retention interval and make no or very few errors. This study is the first to show long-term memory capacity of color stimuli in corvids following a brief training that memory rather than rehearsal was apparent. Memory of visual color information is vital for exploitation of biological resources in crows. We suspect that jungle crows could remember the learned color discrimination task even after a much longer retention interval.

Behavior of reinforced concrete beams reinforced with GFRP bars

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D. H. Tavares

Full Text Available The use of fiber reinforced polymer (FRP bars is one of the alternatives presented in recent studies to prevent the drawbacks related to the steel reinforcement in specific reinforced concrete members. In this work, six reinforced concrete beams were submitted to four point bending tests. One beam was reinforced with CA-50 steel bars and five with glass fiber reinforced polymer (GFRP bars. The tests were carried out in the Department of Structural Engineering in São Carlos Engineering School, São Paulo University. The objective of the test program was to compare strength, reinforcement deformation, displacement, and some anchorage aspects between the GFRP-reinforced concrete beams and the steel-reinforced concrete beam. The results show that, even though four GFRP-reinforced concrete beams were designed with the same internal tension force as that with steel reinforcement, their capacity was lower than that of the steel-reinforced beam. The results also show that similar flexural capacity can be achieved for the steel- and for the GFRP-reinforced concrete beams by controlling the stiffness (reinforcement modulus of elasticity multiplied by the bar cross-sectional area - EA and the tension force of the GFRP bars.

Stimuli-Responsive Polymeric Nanoparticles.

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Liu, Xiaolin; Yang, Ying; Urban, Marek W

2017-07-01

There is increasing evidence that stimuli-responsive nanomaterials have become significantly critical components of modern materials design and technological developments. Recent advances in synthesis and fabrication of stimuli-responsive polymeric nanoparticles with built-in stimuli-responsive components (Part A) and surface modifications of functional nanoparticles that facilitate responsiveness (Part B) are outlined here. The synthesis and construction of stimuli-responsive spherical, core-shell, concentric, hollow, Janus, gibbous/inverse gibbous, and cocklebur morphologies are discussed in Part A, with the focus on shape, color, or size changes resulting from external stimuli. Although inorganic/metallic nanoparticles exhibit many useful properties, including thermal or electrical conductivity, catalytic activity, or magnetic properties, their assemblies and formation of higher order constructs are often enhanced by surface modifications. Section B focuses on selected surface reactions that lead to responsiveness achieved by decorating nanoparticles with stimuli-responsive polymers. Although grafting-to and grafting-from dominate these synthetic efforts, there are opportunities for developing novel synthetic approaches facilitating controllable recognition, signaling, or sequential responses. Many nanotechnologies utilize a combination of organic and inorganic phases to produce ceramic or metallic nanoparticles. One can envision the development of new properties by combining inorganic (metals, metal oxides) and organic (polymer) phases into one nanoparticle designated as "ceramers" (inorganics) and "metamers" (metallic). © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Psychogenic chemical sensitivity: psychogenic pseudoseizures elicited by provocation challenges with fragrances.

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Staudenmayer, H; Kramer, R E

1999-08-01

A middle-aged woman with a 10-year history of disability attributed to chemical sensitivities complained that exposure to specific fragrances immediately elicited seizures. Video-EEG monitoring was performed in a hospital neurodiagnostic laboratory during provocative challenge studies employing fragrances identified by the patient as reliably inducing symptoms. The baseline clinical EEG was normal. Immediately after each provocation with air deodorant and perfume, she consistently showed both generalized tonic/clonic and multifocal myoclonic jerking, at times was nonresponsive, spoke with slurred speech, and complained of right-sided paralysis and lethargy. None of these events were associated with any EEG abnormalities. Psychological assessment (MMPI-2, MCMI-II) revealed personality traits that predisposed her to somatization and beliefs about environmental sensitivities. The convulsions were a manifestation of psychogenic pseudoseizures that had been iatrogenically reinforced.

Valuation of Go Stimuli or Devaluation of No-Go Stimuli? Evidence of an Increased Preference for Attended Go Stimuli Following a Go/No-Go Task.

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Inoue, Kazuya; Sato, Nobuya

2017-01-01

Attentional inhibition that occurs during discrimination tasks leads to the negative evaluation of distractor stimuli. This phenomenon, known as the distractor devaluation effect also occurs when go/no-go tasks require response inhibition. However, it remains unclear whether there are interactions between attention and response controls when the distractor devaluation effect occurs. The aims of this study were to investigate whether attention to stimuli in the go/no-go task plays a facilitative role in distractor devaluation through response inhibition, and to clarify whether this effect reflects a decreased preference for no-go stimuli. Participants evaluated the preference for pictures before and after a go/no-go task. In Experiments 1 and 2, they made a go or no-go response depending on the category of pictures displayed (gummy candies or rice crackers), whereas in Experiment 3 they did on the basis digit category, even or odd numbers, superimposed on such pictures. Experiments 1 and 2 demonstrated that the pictures presented as no-go stimuli in the preceding go/no-go task were evaluated as less positive than the pictures presented as go stimuli. This devaluation effect reflected an increased preference for the go stimuli but not a decreased preference for the no-go stimuli. Experiment 3 indicated that response inhibition did not affect the preference for the pictures that had not received attention in a preceding go/no-go task. These results suggest that although attention plays an important role in differential ratings for go and no-go stimuli, such differences, in fact, reflect the valuation of go stimuli.

Operant conditioning of neural activity in freely behaving monkeys with intracranial reinforcement.

Science.gov (United States)

Eaton, Ryan W; Libey, Tyler; Fetz, Eberhard E

2017-03-01

activity-dependent stimuli to an intracranial reinforcement site (nucleus accumbens). We conditioned increased firing rates with the monkeys seated in a training booth and also, for the first time, during free behavior in a cage using an autonomous head-fixed BCI. Copyright © 2017 the American Physiological Society.

A comparison of five elicitation techniques for elicitation of attributes of low involvement products

DEFF Research Database (Denmark)

Bech-Larsen, Tino; Nielsen, Niels Asger

1999-01-01

of dimensions directed from theories of consumer buying behaviour. Although a number of differences between the techniques are identified in the study, the main findings are that the robustness of the different techniques for attribute elicitation is considerable Udgivelsesdato: JUN......The critical first step for most instruments used in analysing consumer choice and motivation is the identification of product attributes which are important to the consumer and for which there are differences among the available product alternatives. A number of techniques, ranging from...... the complex elicitation of idiosyncratic attributes or simpler picking procedures, has been developed to elicitate such attributes. The purpose of the study presented here is to com-pare attributes of a low involvement product, viz. vegetable oil, elicited by five different techniques on a number...

Effect of Size Change and Brightness Change of Visual Stimuli on Loudness Perception and Pitch Perception of Auditory Stimuli

Directory of Open Access Journals (Sweden)

Syouya Tanabe

2011-10-01

Full Text Available People obtain a lot of information from visual and auditory sensation on daily life. Regarding the effect of visual stimuli on perception of auditory stimuli, studies of phonological perception and sound localization have been made in great numbers. This study examined the effect of visual stimuli on perception in loudness and pitch of auditory stimuli. We used the image of figures whose size or brightness was changed as visual stimuli, and the sound of pure tone whose loudness or pitch was changed as auditory stimuli. Those visual and auditory stimuli were combined independently to make four types of audio-visual multisensory stimuli for psychophysical experiments. In the experiments, participants judged change in loudness or pitch of auditory stimuli, while they judged the direction of size change or the kind of a presented figure in visual stimuli. Therefore they cannot neglect visual stimuli while they judged auditory stimuli. As a result, perception in loudness and pitch were promoted significantly around their difference limen, when the image was getting bigger or brighter, compared with the case in which the image had no changes. This indicates that perception in loudness and pitch were affected by change in size and brightness of visual stimuli.

The use of positive reinforcement in training zebra sharks (Stegostoma fasciatum).

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Marranzino, Ashley

2013-01-01

Positive reinforcement training (PRT) was used on 4 adult zebra sharks, Stegostoma fasciatum, housed at the Downtown Aquarium, Denver, to determine the ability of zebra sharks to become desensitized to various stimuli associated with veterinary procedures. One male and 3 female sharks were trained for 12 weeks. As a result of PRT, all 4 zebra sharks were desensitized to staying within a closed holding tank off of the main exhibit, the presence of multiple trainers in the closed holding tank, and tactile stimulation. One of the 4 zebra sharks was also successfully desensitized to the presence of a stretcher being brought into the holding tank. All of these procedures are common in veterinary examinations, and it is hoped that desensitization to these stimuli will reduce the stress associated with examinations. The training accomplished has allowed for easier maintenance of the zebra sharks by the aquarium staff and an improvement in the care of the sharks.

Autoshaping the pigeon's gape response: acquisition and topography as a function of reinforcer type and magnitude.

Science.gov (United States)

Allan, R W; Zeigler, H P

1994-09-01

The pigeon's key-pecking response is experimentally dissociable into transport (head movement) and gape (jaw movement) components. During conditioning of the key-pecking response, both components come under the control of the conditioned stimulus. To study the acquisition of gape conditioned responses and to clarify the contribution of unconditioned stimulus (reinforcer) variables to the form of the response, gape and key-contact responses were recorded during an autoshaping procedure and reinforcer properties were systematically varied. One group of 8 pigeons was food deprived and subgroups of 2 birds each were exposed to four different pellet sizes as reinforcers, each reinforcer signaled by a keylight conditioned stimulus. A second group was water deprived and received water reinforcers paired with the conditioned stimulus. Water- or food-deprived control groups received appropriate water or food reinforcers that were randomly delivered with respect to the keylight stimulus. Acquisition of the conditioned gape response frequently preceded key-contact responses, and gape conditioned responses were generally elicited at higher rates than were key contacts. The form of the conditioned gape was similar to, but not identical with, the form of the unconditioned gape. The gape component is a critical topographical feature of the conditioned key peck, a sensitive measure of conditioning during autoshaping, and an important source of the observed similarities in the form of conditioned and consummatory responses.

Group behavioural responses of Atlantic salmon (Salmo salar L. to light, infrasound and sound stimuli.

Directory of Open Access Journals (Sweden)

Samantha Bui

Full Text Available Understanding species-specific flight behaviours is essential in developing methods of guiding fish spatially, and requires knowledge on how groups of fish respond to aversive stimuli. By harnessing their natural behaviours, the use of physical manipulation or other potentially harmful procedures can be minimised. We examined the reactions of sea-caged groups of 50 salmon (1331 ± 364 g to short-term exposure to visual or acoustic stimuli. In light experiments, fish were exposed to one of three intensities of blue LED light (high, medium and low or no light (control. Sound experiments included exposure to infrasound (12 Hz, a surface disturbance event, the combination of infrasound and surface disturbance, or no stimuli. Groups that experienced light, infrasound, and the combination of infrasound and surface disturbance treatments, elicited a marked change in vertical distribution, where fish dived to the bottom of the sea-cage for the duration of the stimulus. Light treatments, but not sound, also reduced the total echo-signal strength (indicative of swim bladder volume after exposure to light, compared to pre-stimulus levels. Groups in infrasound and combination treatments showed increased swimming activity during stimulus application, with swimming speeds tripled compared to that of controls. In all light and sound treatments, fish returned to their pre-stimulus swimming depths and speeds once exposure had ceased. This work establishes consistent, short-term avoidance responses to these stimuli, and provides a basis for methods to guide fish for aquaculture applications, or create avoidance barriers for conservation purposes. In doing so, we can achieve the manipulation of group position with minimal welfare impacts, to create more sustainable practices.

A comparison of sound quality judgments for monaural and binaural hearing aid processed stimuli.

Science.gov (United States)

Balfour, P B; Hawkins, D B

1992-10-01

Fifteen adults with bilaterally symmetrical mild and/or moderate sensorineural hearing loss completed a paired-comparison task designed to elicit sound quality preference judgments for monaural/binaural hearing aid processed signals. Three stimuli (speech-in-quiet, speech-in-noise, and music) were recorded separately in three listening environments (audiometric test booth, living room, and a music/lecture hall) through hearing aids placed on a Knowles Electronics Manikin for Acoustics Research. Judgments were made on eight separate sound quality dimensions (brightness, clarity, fullness, loudness, nearness, overall impression, smoothness, and spaciousness) for each of the three stimuli in three listening environments. Results revealed a distinct binaural preference for all eight sound quality dimensions independent of listening environment. Binaural preferences were strongest for overall impression, fullness, and spaciousness. Stimulus type effect was significant only for fullness and spaciousness, where binaural preferences were strongest for speech-in-quiet. After binaural preference data were obtained, subjects ranked each sound quality dimension with respect to its importance for binaural listening relative to monaural. Clarity was ranked highest in importance and brightness was ranked least important. The key to demonstration of improved binaural hearing aid sound quality may be the use of a paired-comparison format.

Temporal attention for visual food stimuli in restrained eaters.

Science.gov (United States)

Neimeijer, Renate A M; de Jong, Peter J; Roefs, Anne

2013-05-01

Although restrained eaters try to limit their food intake, they often fail and indulge in exactly those foods that they want to avoid. A possible explanation is a temporal attentional bias for food cues. It could be that for these people food stimuli are processed relatively efficiently and require less attentional resources to enter awareness. Once a food stimulus has captured attention, it may be preferentially processed and granted prioritized access to limited cognitive resources. This might help explain why restrained eaters often fail in their attempts to restrict their food intake. A Rapid Serial Visual Presentation task consisting of dual and single target trials with food and neutral pictures as targets and/or distractors was administered to restrained (n=40) and unrestrained (n=40) eaters to study temporal attentional bias. Results indicated that (1) food cues did not diminish the attentional blink in restrained eaters when presented as second target; (2) specifically restrained eaters showed an interference effect of identifying food targets on the identification of preceding neutral targets; (3) for both restrained and unrestrained eaters, food cues enhanced the attentional blink; (4) specifically in restrained eaters, food distractors elicited an attention blink in the single target trials. In restrained eaters, food cues get prioritized access to limited cognitive resources, even if this processing priority interferes with their current goals. This temporal attentional bias for food stimuli might help explain why restrained eaters typically have difficulties maintaining their diet rules. Copyright © 2012 Elsevier Ltd. All rights reserved.

Neural correlates of derived relational responding on tests of stimulus equivalence

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Cataldo Michael F

2008-02-01

Full Text Available Abstract Background An essential component of cognition and language involves the formation of new conditional relations between stimuli based upon prior experiences. Results of investigations on transitive inference (TI highlight a prominent role for the medial temporal lobe in maintaining associative relations among sequentially arranged stimuli (A > B > C > D > E. In this investigation, medial temporal lobe activity was assessed while subjects completed "Stimulus Equivalence" (SE tests that required deriving conditional relations among stimuli within a class (A ≡ B ≡ C. Methods Stimuli consisted of six consonant-vowel-consonant triads divided into two classes (A1, B1, C1; A2, B2, C2. A simultaneous matching-to-sample task and differential reinforcement were employed during pretraining to establish the conditional relations A1:B1 and B1:C1 in class 1 and A2:B2 and B2:C2 in class 2. During functional neuroimaging, recombined stimulus pairs were presented and subjects judged (yes/no whether stimuli were related. SE tests involved presenting three different types of within-class pairs: Symmetrical (B1 A1; C1 B1; B2 A2; C2 B2, and Transitive (A1 C1; A2 C2 and Equivalence (C1 A1; C2 A2 relations separated by a nodal stimulus. Cross-class 'Foils' consisting of unrelated stimuli (e.g., A1 C2 were also presented. Results Relative to cross-class Foils, Transitive and Equivalence relations requiring inferential judgments elicited bilateral activation in the anterior hippocampus while Symmetrical relations elicited activation in the parahippocampus. Relative to each derived relation, Foils generally elicited bilateral activation in the parahippocampus, as well as in frontal and parietal lobe regions. Conclusion Activation observed in the hippocampus to nodal-dependent derived conditional relations (Transitive and Equivalence relations highlights its involvement in maintaining relational structure and flexible memory expression among stimuli within a

Braided reinforced composite rods for the internal reinforcement of concrete

Science.gov (United States)

Gonilho Pereira, C.; Fangueiro, R.; Jalali, S.; Araujo, M.; Marques, P.

2008-05-01

This paper reports on the development of braided reinforced composite rods as a substitute for the steel reinforcement in concrete. The research work aims at understanding the mechanical behaviour of core-reinforced braided fabrics and braided reinforced composite rods, namely concerning the influence of the braiding angle, the type of core reinforcement fibre, and preloading and postloading conditions. The core-reinforced braided fabrics were made from polyester fibres for producing braided structures, and E-glass, carbon, HT polyethylene, and sisal fibres were used for the core reinforcement. The braided reinforced composite rods were obtained by impregnating the core-reinforced braided fabric with a vinyl ester resin. The preloading of the core-reinforced braided fabrics and the postloading of the braided reinforced composite rods were performed in three and two stages, respectively. The results of tensile tests carried out on different samples of core-reinforced braided fabrics are presented and discussed. The tensile and bending properties of the braided reinforced composite rods have been evaluated, and the results obtained are presented, discussed, and compared with those of conventional materials, such as steel.

Requirements Elicitation Problems: A Literature Analysis

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Bill Davey

2015-06-01

Full Text Available Requirements elicitation is the process through which analysts determine the software requirements of stakeholders. Requirements elicitation is seldom well done, and an inaccurate or incomplete understanding of user requirements has led to the downfall of many software projects. This paper proposes a classification of problem types that occur in requirements elicitation. The classification has been derived from a literature analysis. Papers reporting on techniques for improving requirements elicitation practice were examined for the problem the technique was designed to address. In each classification the most recent or prominent techniques for ameliorating the problems are presented. The classification allows the requirements engineer to be sensitive to problems as they arise and the educator to structure delivery of requirements elicitation training.

Belief Elicitation in Experiments

DEFF Research Database (Denmark)

Blanco, Mariana; Engelmann, Dirk; Koch, Alexander

Belief elicitation in economics experiments usually relies on paying subjects according to the accuracy of stated beliefs in addition to payments for other decisions. Such incentives, however, allow risk-averse subjects to hedge with their stated beliefs against adverse outcomes of other decisions......-belief elicitation treatment using a financial investment frame, where hedging arguably would be most natural....

Object habituation in horses: The effect of voluntary vs. negatively reinforced approach to frightening stimuli

DEFF Research Database (Denmark)

Christensen, Janne Winther

2013-01-01

of the horses (NR group) were negatively reinforced by a familiar human handler to approach a collection of novel objects in a test arena. The other half were individually released in the arena and were free to explore the objects (VOL group). On the next day, the horses were exposed to the objects again...... without a human handler, to investigate the rate of habituation. Behavioural and heart rate responses were recorded. Results: All VOL horses initially avoided the unknown objects, whereas the handler was able to get all NR horses to approach and stand next to the objects within the first 2 min session...

Flexural reinforced concrete member with FRP reinforcement

OpenAIRE

Putzolu, Mariana

2017-01-01

One of the most problematic point in construction is the durability of the concrete especially related to corrosion of the steel reinforcement. Due to this problem the construction sector, introduced the use of Fiber Reinforced Polymer, the main fibers used in construction are Glass, Carbon and Aramid. In this study, the author aim to analyse the flexural behaviour of concrete beams reinforced with FRP. This aim is achieved by the analysis of specimens reinforced with GFRP bars, with theoreti...

Effects of sucrose concentration and water deprivation on Pavlovian conditioning and responding for conditioned reinforcement.

Science.gov (United States)

Tabbara, Rayane I; Maddux, Jean-Marie N; Beharry, Priscilla F; Iannuzzi, Jessica; Chaudhri, Nadia

2016-04-01

An appetitive Pavlovian conditioned stimulus (CS) can predict an unconditioned stimulus (US) and acquire incentive salience. We tested the hypothesis that US intensity and motivational state of the subject would influence Pavlovian learning and impact the attribution of incentive salience to an appetitive Pavlovian CS. To this end, we examined the effects of sucrose concentration and water deprivation on the acquisition of Pavlovian conditioning and responding for a conditioned reinforcer. Male Long-Evans rats (Harlan; 220-240 g) receiving 3% (3S) or 20% (20S) sucrose were either non-water deprived or given water for 1 hr per day. During Pavlovian conditioning sessions, half the rats in each concentration and deprivation condition received a 10-s CS paired with 0.2 ml of sucrose (16 trials/session; 3.2 ml/session). The remainder received unpaired CS and US presentations. Entries into a port where sucrose was delivered were recorded. Next, responding for conditioned reinforcement was tested, wherein pressing an active lever produced the CS and pressing an inactive lever had no consequences. CS-elicited port entries increased, and latency to the first CS-elicited port entry decreased across sessions in paired groups. Water deprivation augmented these effects, whereas sucrose concentration had no significant impact on behavior. Responding for conditioned reinforcement was observed in the 20S water-deprived, paired group. Thus, water deprivation can facilitate the acquisition of Pavlovian conditioning, potentially by enhancing motivational state, and a high-intensity US and a high motivational state can interact to heighten the attribution of incentive salience to an appetitive Pavlovian CS. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Eliciting extra prominence in read-speech tasks: The effects of different text-highlighting methods on acoustic cues to perceived prominence

DEFF Research Database (Denmark)

Berger, Stephanie; Niebuhr, Oliver; Fischer, Kerstin

2018-01-01

The research initiative Innovating Speech EliCitation Techniques (INSPECT) aims to describe and quantify how recording methods, situations and materials influence speech produc-tion in lab-speech experiments. On this basis, INSPECT aims to develop methods that reliably stimulate specific patterns...... and styles of speech, like expressive or conversational speech or different types emphatic accents. The present study investigates if and how different text highlighting methods (yellow background, bold, capital letter, italics, and underlining) make speakers reinforce the level of perceived prominence...

Do animals and furniture items elicit different brain responses in human infants?

Science.gov (United States)

Jeschonek, Susanna; Marinovic, Vesna; Hoehl, Stefanie; Elsner, Birgit; Pauen, Sabina

2010-11-01

One of the earliest categorical distinctions to be made by preverbal infants is the animate-inanimate distinction. To explore the neural basis for this distinction in 7-8-month-olds, an equal number of animal and furniture pictures was presented in an ERP-paradigm. The total of 118 pictures, all looking different from each other, were presented in a semi-randomized order for 1000ms each. Infants' brain responses to exemplars from both categories differed systematically regarding the negative central component (Nc: 400-600ms) at anterior channels. More specifically, the Nc was enhanced for animals in one subgroup of infants, and for furniture items in another subgroup of infants. Explorative analyses related to categorical priming further revealed category-specific differences in brain responses in the late time window (650-1550ms) at right frontal channels: Unprimed stimuli (preceded by a different-category item) elicited a more positive response as compared to primed stimuli (preceded by a same-category item). In sum, these findings suggest that the infant's brain discriminates exemplars from both global domains. Given the design of our task, we conclude that processes of category identification are more likely to account for our findings than processes of on-line category formation during the experimental session. Copyright © 2009 Elsevier B.V. All rights reserved.

Emotional stimuli and motor conversion disorder

NARCIS (Netherlands)

Voon, V.; Brezing, C.; Gallea, C.; Ameli, R.; Roelofs, K.; LaFrance, W.C.; Hallett, M.

2010-01-01

Conversion disorder is characterized by neurological signs and symptoms related to an underlying psychological issue. Amygdala activity to affective stimuli is well characterized in healthy volunteers with greater amygdala activity to both negative and positive stimuli relative to neutral stimuli,

Sleep deprivation affects reactivity to positive but not negative stimuli.

Science.gov (United States)

Pilcher, June J; Callan, Christina; Posey, J Laura

2015-12-01

The current study examined the effects of partial and total sleep deprivation on emotional reactivity. Twenty-eight partially sleep-deprived participants and 31 totally sleep-deprived participants rated their valence and arousal responses to positive and negative pictures across four testing sessions during the day following partial sleep deprivation or during the night under total sleep deprivation. The results suggest that valence and arousal ratings decreased under both sleep deprivation conditions. In addition, partial and total sleep deprivation had a greater negative effect on positive events than negative events. These results suggest that sleep-deprived persons are more likely to respond less to positive events than negative events. One explanation for the current findings is that negative events could elicit more attentive behavior and thus stable responding under sleep deprivation conditions. As such, sleep deprivation could impact reactivity to emotional stimuli through automated attentional and self-regulatory processes. Copyright © 2015 Elsevier Inc. All rights reserved.

Emotional Stimuli and Motor Conversion Disorder

Science.gov (United States)

Voon, Valerie; Brezing, Christina; Gallea, Cecile; Ameli, Rezvan; Roelofs, Karin; LaFrance, W. Curt, Jr.; Hallett, Mark

2010-01-01

Conversion disorder is characterized by neurological signs and symptoms related to an underlying psychological issue. Amygdala activity to affective stimuli is well characterized in healthy volunteers with greater amygdala activity to both negative and positive stimuli relative to neutral stimuli, and greater activity to negative relative to…

Eliciting Sound Memories.

Science.gov (United States)

Harris, Anna

2015-11-01

Sensory experiences are often considered triggers of memory, most famously a little French cake dipped in lime blossom tea. Sense memory can also be evoked in public history research through techniques of elicitation. In this article I reflect on different social science methods for eliciting sound memories such as the use of sonic prompts, emplaced interviewing, and sound walks. I include examples from my research on medical listening. The article considers the relevance of this work for the conduct of oral histories, arguing that such methods "break the frame," allowing room for collaborative research connections and insights into the otherwise unarticulatable.

Study on reinforced concrete beams with helical transverse reinforcement

Science.gov (United States)

Kaarthik Krishna, N.; Sandeep, S.; Mini, K. M.

2018-02-01

In a Reinforced Concrete (R.C) structure, major reinforcement is used for taking up tensile stresses acting on the structure due to applied loading. The present paper reports the behavior of reinforced concrete beams with helical reinforcement (transverse reinforcement) subjected to monotonous loading by 3-point flexure test. The results were compared with identically similar reinforced concrete beams with rectangular stirrups. During the test crack evolution, load carrying capacity and deflection of the beams were monitored, analyzed and compared. Test results indicate that the use of helical reinforcement provides enhanced load carrying capacity and a lower deflection proving to be more ductile, clearly indicating the advantage in carrying horizontal loads. An analysis was also carried out using ANSYS software in order to compare the test results of both the beams.

Olfactory cues are subordinate to visual stimuli in a neotropical generalist weevil.

Directory of Open Access Journals (Sweden)

Fernando Otálora-Luna

Full Text Available The tropical root weevil Diaprepes abbreviatus is a major pest of multiple crops in the Caribbean Islands and has become a serious constraint to citrus production in the United States. Recent work has identified host and conspecific volatiles that mediate host- and mate-finding by D. abbreviatus. The interaction of light, color, and odors has not been studied in this species. The responses of male and female D. abbreviatus to narrow bandwidths of visible light emitted by LEDs offered alone and in combination with olfactory stimuli were studied in a specially-designed multiple choice arena combined with a locomotion compensator. Weevils were more attracted to wavelengths close to green and yellow compared with blue or ultraviolet, but preferred red and darkness over green. Additionally, dim green light was preferred over brighter green. Adult weevils were also attracted to the odor of its citrus host + conspecifics. However, the attractiveness of citrus + conspecific odors disappeared in the presence of a green light. Photic stimulation induced males but not females to increase their speed. In the presence of light emitted by LEDs, turning speed decreased and path straightness increased, indicating that weevils tended to walk less tortuously. Diaprepes abbreviatus showed a hierarchy between chemo- and photo-taxis in the series of experiments presented herein, where the presence of the green light abolished upwind anemotaxis elicited by the pheromone + host plant odor. Insight into the strong responses to visual stimuli of chemically stimulated insects may be provided when the amount of information supplied by vision and olfaction is compared, as the information transmission capacity of compound eyes is estimated to be several orders of magnitude higher compared with the olfactory system. Subordination of olfactory responses by photic stimuli should be considered in the design of strategies aimed at management of such insects.

The neural response to maternal stimuli: an ERP study.

Directory of Open Access Journals (Sweden)

Lili Wu

Full Text Available Mothers are important to all humans. Research has established that maternal information affects individuals' cognition, emotion, and behavior. We measured event-related potentials (ERPs to examine attentional and evaluative processing of maternal stimuli while participants completed a Go/No-go Association Task that paired mother or others words with good or bad evaluative words. Behavioral data showed that participants responded faster to mother words paired with good than the mother words paired with bad but showed no difference in response to these others across conditions, reflecting a positive evaluation of mother. ERPs showed larger P200 and N200 in response to mother than in response to others, suggesting that mother attracted more attention than others. In the subsequent time window, mother in the mother + bad condition elicited a later and larger late positive potential (LPP than it did in the mother + good condition, but this was not true for others, also suggesting a positive evaluation of mother. These results suggest that people differentiate mother from others during initial attentional stage, and evaluative mother positively during later stage.

Mate call as reward: Acoustic communication signals can acquire positive reinforcing values during adulthood in female zebra finches (Taeniopygia guttata).

Science.gov (United States)

Hernandez, Alexandra M; Perez, Emilie C; Mulard, Hervé; Mathevon, Nicolas; Vignal, Clémentine

2016-02-01

Social stimuli can have rewarding properties and promote learning. In birds, conspecific vocalizations like song can act as a reinforcer, and specific song variants can acquire particular rewarding values during early life exposure. Here we ask if, during adulthood, an acoustic signal simpler and shorter than song can become a reward for a female songbird because of its particular social value. Using an operant choice apparatus, we showed that female zebra finches display a preferential response toward their mate's calls. This reinforcing value of mate's calls could be involved in the maintenance of the monogamous pair-bond of the zebra finch. (c) 2016 APA, all rights reserved).

REINFORCED COMPOSITE PANEL

DEFF Research Database (Denmark)

2003-01-01

A composite panel having front and back faces, the panel comprising facing reinforcement, backing reinforcement and matrix material binding to the facing and backing reinforcements, the facing and backing reinforcements each independently comprising one or more reinforcing sheets, the facing rein...... by matrix material, the facing and backing reinforcements being interconnected to resist out-of-plane relative movement. The reinforced composite panel is useful as a barrier element for shielding structures, equipment and personnel from blast and/or ballistic impact damage....

Effects of Vigabatrin, an Irreversible GABA Transaminase Inhibitor, on Ethanol Reinforcement and Ethanol Discriminative Stimuli in Mice

Science.gov (United States)

Griffin, William C.; Nguyen, Shaun A.; Deleon, Christopher P.; Middaugh, Lawrence D.

2012-01-01

We tested the hypothesis that the irreversible gamma-amino butyric acid (GABA) transaminase inhibitor, γ-vinyl GABA (Vigabatrin; VGB) would reduce ethanol reinforcement and enhance the discriminative stimulus effect of ethanol, effectively reducing ethanol intake. The present studies used adult C57BL/6J (B6) mice in well-established operant, two-bottle choice consumption, locomotor activity and ethanol discrimination procedures, to examine comprehensively the effects of VGB on ethanol-supported behaviors. VGB dose-dependently reduced operant responding for ethanol as well as ethanol consumption for long periods of time. Importantly, a low dose (200 mg/kg) of VGB was selective for reducing ethanol responding without altering intake of food or water reinforcement. Higher VGB doses (>200 mg/kg) still reduced ethanol intake, but also significantly increased water consumption and, more modestly, increased food consumption. While not affecting locomotor activity on its own, VGB interacted with ethanol to reduce the stimulatory effects of ethanol on locomotion. Finally, VGB (200 mg/kg) significantly enhanced the discriminative stimulus effects of ethanol as evidenced by significant left-ward and up-ward shifts in ethanol generalization curves. Interestingly, VGB treatment was associated with slight increases in blood ethanol concentrations. The reduction in ethanol intake by VGB appears to be related to the ability of VGB to potentiate the pharmacological effects of ethanol. PMID:22336593

Expert Panel Elicitation

Energy Technology Data Exchange (ETDEWEB)

Jensen, M. [Swedish Radiation Protection Authority, Stockholm (Sweden). Dept. of Waste Management and Environmental Protection; Hora, S.C. [Univ. of Hawaii, Hilo, HI (United States)

2005-09-15

Scientists are now frequently in a situation where data cannot be easily assessed, since they may have conflicting or uncertain sources. While expert judgment reflects private choices, it is possible both reduce the personal aspect as well as in crease confidence in the judgments by using formal protocols for choice and elicitation of experts. A full-scale elicitation made on seismicity following glaciation, now in its late phase and presented here in a preliminary form, illustrates the value of the technique and some essential issues in connection with the decision to launch such a project. The results show an unusual low variation between the experts.

Use of frontal lobe hemodynamics as reinforcement signals to an adaptive controller.

Directory of Open Access Journals (Sweden)

Marcello M DiStasio

Full Text Available Decision-making ability in the frontal lobe (among other brain structures relies on the assignment of value to states of the animal and its environment. Then higher valued states can be pursued and lower (or negative valued states avoided. The same principle forms the basis for computational reinforcement learning controllers, which have been fruitfully applied both as models of value estimation in the brain, and as artificial controllers in their own right. This work shows how state desirability signals decoded from frontal lobe hemodynamics, as measured with near-infrared spectroscopy (NIRS, can be applied as reinforcers to an adaptable artificial learning agent in order to guide its acquisition of skills. A set of experiments carried out on an alert macaque demonstrate that both oxy- and deoxyhemoglobin concentrations in the frontal lobe show differences in response to both primarily and secondarily desirable (versus undesirable stimuli. This difference allows a NIRS signal classifier to serve successfully as a reinforcer for an adaptive controller performing a virtual tool-retrieval task. The agent's adaptability allows its performance to exceed the limits of the NIRS classifier decoding accuracy. We also show that decoding state desirabilities is more accurate when using relative concentrations of both oxyhemoglobin and deoxyhemoglobin, rather than either species alone.

Reinforcement Magnitude: An Evaluation of Preference and Reinforcer Efficacy

OpenAIRE

Trosclair-Lasserre, Nicole M; Lerman, Dorothea C; Call, Nathan A; Addison, Laura R; Kodak, Tiffany

2008-01-01

Consideration of reinforcer magnitude may be important for maximizing the efficacy of treatment for problem behavior. Nonetheless, relatively little is known about children's preferences for different magnitudes of social reinforcement or the extent to which preference is related to differences in reinforcer efficacy. The purpose of the current study was to evaluate the relations among reinforcer magnitude, preference, and efficacy by drawing on the procedures and results of basic experimenta...

Binocular Combination of Second-Order Stimuli

Science.gov (United States)

Zhou, Jiawei; Liu, Rong; Zhou, Yifeng; Hess, Robert F.

2014-01-01

Phase information is a fundamental aspect of visual stimuli. However, the nature of the binocular combination of stimuli defined by modulations in contrast, so-called second-order stimuli, is presently not clear. To address this issue, we measured binocular combination for first- (luminance modulated) and second-order (contrast modulated) stimuli using a binocular phase combination paradigm in seven normal adults. We found that the binocular perceived phase of second-order gratings depends on the interocular signal ratio as has been previously shown for their first order counterparts; the interocular signal ratios when the two eyes were balanced was close to 1 in both first- and second-order phase combinations. However, second-order combination is more linear than previously found for first-order combination. Furthermore, binocular combination of second-order stimuli was similar regardless of whether the carriers in the two eyes were correlated, anti-correlated, or uncorrelated. This suggests that, in normal adults, the binocular phase combination of second-order stimuli occurs after the monocular extracting of the second-order modulations. The sensory balance associated with this second-order combination can be obtained from binocular phase combination measurements. PMID:24404180

[Choice between probability and value of alimentary reinforcement as means for revealing individual typological features of dog behavior].

Science.gov (United States)

Chilingarian, L I

2005-01-01

Individual typological features of behavior of dogs were investigated by the method of choice between the low-valuable food available constantly and food of high quality presented with low probability. Animals were subjected to instrumental conditioning with the same conditioned stimuli but different types of reinforcement. Depression of a white pedal was always reinforced with meat-bread-crumb mixture, depression of a black pedal was reinforced with two pieces of liver (with probabilities of 100, 40, 33, 20, or 0%). The choice of reinforcement depended on probability of valuable food and individual typological features of the nervous system of a dog. Decreasing the probability of the reinforcement value to 40-20% revealed differences in behavior of dogs. Dogs of the first group, presumably with the weak type of the nervous system, more frequently pressed the white pedal (always reinforced) than the black pedal thus "avoiding a situation of risk" to receive an empty cup. They displayed symptoms of neurosis: whimper, refusals of food or of the choice of reinforcement, and obtrusive movements. Dogs of the second group, presumably with the strong type of the nervous system, more frequently pressed the black pedal (more valuable food) for the low-probability reward until they obtained the valuable food. They did not show neurosis symptoms and were not afraid of "situation of risk". A decrease in probability of the valuable reinforcement increased a percentage of long-latency depressions of pedals. It can be probably suggested that this phenomenon was associated with increasing involvement of cognitive processes, when contributions of the assessments of probability and value of the reinforcement to decision making became approximately equal. Choice between the probability and value of alimentary reinforcement is a good method for revealing individual typological features of dogs.

The impact of high- and low-preference stimuli on vocational and academic performances of youths with severe disabilities.

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Graff, Richard B; Gibson, Lenwood; Galiatsatos, G Tracey

2006-01-01

Pictorial and tangible paired-stimulus preference assessments were compared with 4 adolescents with developmental disabilities. In the tangible assessment, two stimuli were placed in front of the participant on each trial; in the pictorial assessment, two line drawings were placed in front of the participant on each trial. Approach responses were recorded for each assessment. The assessments generated similar preference hierarchies for all participants. Reinforcer assessments confirmed that response rates were higher when access to high-preference items was available than when low-preference items were available. Implications for assessing preferences and selecting items to be used in training programs are discussed.

Reinforced sulphur concrete

NARCIS (Netherlands)

2014-01-01

Reinforced sulphur concrete wherein one or more metal reinforcing members are in contact with sulphur concrete is disclosed. The reinforced sulphur concrete comprises an adhesion promoter that enhances the interaction between the sulphur and the one or more metal reinforcing members.

Elicitation of ostomy pouch preferences

DEFF Research Database (Denmark)

Bonnichsen, Ole

2011-01-01

Background: Previous studies about patients who have undergone ostomy surgery commonly address the issues of the surgery, complications, preoperative counseling, quality of life, and psychosocial changes following surgery. Only a limited number of studies deal with how technical improvements...... in stoma care would affect patients and, to the author's knowledge, the present study is the first to elicit preferences for potential improvements in ostomy pouches in the form of monetary values. Objective: This article examines and measures Swedish patients' preferences for potential improvements...... in ostomy pouch attributes. The theory, study design, elicitation procedure, and resulting preference structure of the sample is described. Methods: A discrete-choice experiment (DCE) was used to elicit preferences. Respondents were asked to choose between alternatives in choice sets, in which each...

A SYSTEMATIC LITERATURE REVIEW ABOUT SOFTWARE REQUIREMENTS ELICITATION

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LENIS R. WONG

2017-02-01

Full Text Available Requirements Elicitation is recognized as one of the most important activity in software development process as it has direct impact on its success. Although there are many proposals for improving this task, still there are issues which have to be solved. This paper aims to identify the current status of the latest researches related to software requirements elicitation through general framework for literature review, in order to answer the following research questions: Q1 What aspects have been covered by different proposal of requirements elicitation? Q2 What activities of the requirements elicitation process have been covered? And Q3 What factors influence on requirements elicitation and how? A cross-analysis of the outcome was performed. One of the results showed that requirements elicitation process needs improvements.

Can persons with dementia be engaged with stimuli?

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Cohen-Mansfield, Jiska; Marx, Marcia S; Dakheel-Ali, Maha; Regier, Natalie G; Thein, Khin

2010-04-01

To determine which stimuli are 1) most engaging 2) most often refused by nursing home residents with dementia, and 3) most appropriate for persons who are more difficult to engage with stimuli. Participants were 193 residents of seven Maryland nursing homes. All participants had a diagnosis of dementia. Stimulus engagement was assessed by the Observational Measure of Engagement. The most engaging stimuli were one-on-one socializing with a research assistant, a real baby, personalized stimuli based on the person's self-identity, a lifelike doll, a respite video, and envelopes to stamp. Refusal of stimuli was higher among those with higher levels of cognitive function and related to the stimulus' social appropriateness. Women showed more attention and had more positive attitudes for live social stimuli, simulated social stimuli, and artistic tasks than did men. Persons with comparatively higher levels of cognitive functioning were more likely to be engaged in manipulative and work tasks, whereas those with low levels of cognitive functioning spent relatively more time responding to social stimuli. The most effective stimuli did not differ for those most likely to be engaged and those least likely to be engaged. Nursing homes should consider both having engagement stimuli readily available to residents with dementia, and implementing a socialization schedule so that residents receive one-on-one interaction. Understanding the relationship among type of stimulus, cognitive function, and acceptance, attention, and attitude toward the stimuli can enable caregivers to maximize the desired benefit for persons with dementia.

Sex differences in brain activation to emotional stimuli: a meta-analysis of neuroimaging studies.

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Stevens, Jennifer S; Hamann, Stephan

2012-06-01

Substantial sex differences in emotional responses and perception have been reported in previous psychological and psychophysiological studies. For example, women have been found to respond more strongly to negative emotional stimuli, a sex difference that has been linked to an increased risk of depression and anxiety disorders. The extent to which such sex differences are reflected in corresponding differences in regional brain activation remains a largely unresolved issue, however, in part because relatively few neuroimaging studies have addressed this issue. Here, by conducting a quantitative meta-analysis of neuroimaging studies, we were able to substantially increase statistical power to detect sex differences relative to prior studies, by combining emotion studies which explicitly examined sex differences with the much larger number of studies that examined only women or men. We used an activation likelihood estimation approach to characterize sex differences in the likelihood of regional brain activation elicited by emotional stimuli relative to non-emotional stimuli. We examined sex differences separately for negative and positive emotions, in addition to examining all emotions combined. Sex differences varied markedly between negative and positive emotion studies. The majority of sex differences favoring women were observed for negative emotion, whereas the majority of the sex differences favoring men were observed for positive emotion. This valence-specificity was particularly evident for the amygdala. For negative emotion, women exhibited greater activation than men in the left amygdala, as well as in other regions including the left thalamus, hypothalamus, mammillary bodies, left caudate, and medial prefrontal cortex. In contrast, for positive emotion, men exhibited greater activation than women in the left amygdala, as well as greater activation in other regions including the bilateral inferior frontal gyrus and right fusiform gyrus. These meta

Redox rhythm reinforces the circadian clock to gate immune response.

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Zhou, Mian; Wang, Wei; Karapetyan, Sargis; Mwimba, Musoki; Marqués, Jorge; Buchler, Nicolas E; Dong, Xinnian

2015-07-23

Recent studies have shown that in addition to the transcriptional circadian clock, many organisms, including Arabidopsis, have a circadian redox rhythm driven by the organism's metabolic activities. It has been hypothesized that the redox rhythm is linked to the circadian clock, but the mechanism and the biological significance of this link have only begun to be investigated. Here we report that the master immune regulator NPR1 (non-expressor of pathogenesis-related gene 1) of Arabidopsis is a sensor of the plant's redox state and regulates transcription of core circadian clock genes even in the absence of pathogen challenge. Surprisingly, acute perturbation in the redox status triggered by the immune signal salicylic acid does not compromise the circadian clock but rather leads to its reinforcement. Mathematical modelling and subsequent experiments show that NPR1 reinforces the circadian clock without changing the period by regulating both the morning and the evening clock genes. This balanced network architecture helps plants gate their immune responses towards the morning and minimize costs on growth at night. Our study demonstrates how a sensitive redox rhythm interacts with a robust circadian clock to ensure proper responsiveness to environmental stimuli without compromising fitness of the organism.

Reinforcement Magnitude: An Evaluation of Preference and Reinforcer Efficacy

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Trosclair-Lasserre, Nicole M.; Lerman, Dorothea C.; Call, Nathan A.; Addison, Laura R.; Kodak, Tiffany

2008-01-01

Consideration of reinforcer magnitude may be important for maximizing the efficacy of treatment for problem behavior. Nonetheless, relatively little is known about children's preferences for different magnitudes of social reinforcement or the extent to which preference is related to differences in reinforcer efficacy. The purpose of the current…

Autoshaping Chicks with Heat Reinforcement: The Role of Stimulus-Reinforcer and Response-Reinforcer Relations

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Wasserman, Edward A.; And Others

1975-01-01

The present series of experiments attempted to analyze more fully the contributions of stimulus-reinforcer and response-reinforcer relations to autoshaping within a single conditioning situation. (Author)

Chronic alcohol intake abolishes the relationship between dopamine synthesis capacity and learning signals in the ventral striatum

DEFF Research Database (Denmark)

Deserno, Lorenz; Beck, Anne; Huys, Quentin J. M.

2015-01-01

Drugs of abuse elicit dopamine release in the ventral striatum, possibly biasing dopamine-driven reinforcement learning towards drug-related reward at the expense of non-drug-related reward. Indeed, in alcohol-dependent patients, reactivity in dopaminergic target areas is shifted from non-drug......-related stimuli towards drug-related stimuli. Such ‘hijacked’ dopamine signals may impair flexible learning from non-drug-related rewards, and thus promote craving for the drug of abuse. Here, we used functional magnetic resonance imaging to measure ventral striatal activation by reward prediction errors (RPEs......) during a probabilistic reversal learning task in recently detoxified alcohol-dependent patients and healthy controls (N = 27). All participants also underwent 6-[18F]fluoro-DOPA positron emission tomography to assess ventral striatal dopamine synthesis capacity. Neither ventral striatal activation...

Multi-Variate EEG Analysis as a Novel Tool to Examine Brain Responses to Naturalistic Music Stimuli.

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Irene Sturm

Full Text Available Note onsets in music are acoustic landmarks providing auditory cues that underlie the perception of more complex phenomena such as beat, rhythm, and meter. For naturalistic ongoing sounds a detailed view on the neural representation of onset structure is hard to obtain, since, typically, stimulus-related EEG signatures are derived by averaging a high number of identical stimulus presentations. Here, we propose a novel multivariate regression-based method extracting onset-related brain responses from the ongoing EEG. We analyse EEG recordings of nine subjects who passively listened to stimuli from various sound categories encompassing simple tone sequences, full-length romantic piano pieces and natural (non-music soundscapes. The regression approach reduces the 61-channel EEG to one time course optimally reflecting note onsets. The neural signatures derived by this procedure indeed resemble canonical onset-related ERPs, such as the N1-P2 complex. This EEG projection was then utilized to determine the Cortico-Acoustic Correlation (CACor, a measure of synchronization between EEG signal and stimulus. We demonstrate that a significant CACor (i can be detected in an individual listener's EEG of a single presentation of a full-length complex naturalistic music stimulus, and (ii it co-varies with the stimuli's average magnitudes of sharpness, spectral centroid, and rhythmic complexity. In particular, the subset of stimuli eliciting a strong CACor also produces strongly coordinated tension ratings obtained from an independent listener group in a separate behavioral experiment. Thus musical features that lead to a marked physiological reflection of tone onsets also contribute to perceived tension in music.

Examining Recall Memory in Infancy and Early Childhood Using the Elicited Imitation Paradigm.

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Lukowski, Angela F; Milojevich, Helen M

2016-04-28

The ability to recall the past allows us to report on details of previous experiences, from the everyday to the significant. Because recall memory is commonly assessed using verbal report paradigms in adults, studying the development of this ability in preverbal infants and children proved challenging. Over the past 30 years, researchers have developed a non-verbal means of assessing recall memory known as the elicited or deferred imitation paradigm. In one variant of the procedure, participants are presented with novel three-dimensional stimuli for a brief baseline period before a researcher demonstrates a series of actions that culminate in an end- or goal-state. The participant is allowed to imitate the demonstrated actions immediately, after a delay, or both. Recall performance is then compared to baseline or to performance on novel control sequences presented at the same session; memory can be assessed for the individual target actions and the order in which they were completed. This procedure is an accepted analogue to the verbal report techniques used with adults, and it has served to establish a solid foundation of the nature of recall memory in infancy and early childhood. In addition, the elicited or deferred imitation procedure has been modified and adapted to answer questions relevant to other aspects of cognitive functioning. The broad utility and application of imitation paradigms is discussed, along with limitations of the approach and directions for future research.

Developing Affective Mental Imagery Stimuli with Multidimensional Scaling

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Matthew J. Facciani

2015-06-01

Full Text Available The goal of this paper is to provide an example of how multidimensional scaling (MDS can be used for stimuli development. The study described in this paper illustrates this process by developing affective mental imagery stimuli using the circumplex model of affect as a guide. The circumplex model of affect argues that all emotions can be described in terms of two underlying primary dimensions: valence and arousal (Russel, 1980. We used MDS to determine if affective mental imagery stimuli obtained from verbal prompts could be separated by arousal and valence to create four distinct categories (high –positive, low-positive, high-negative, and low-negative as seen in other stimuli. 60 students from the University of South Carolina participated in the first experiment to evaluate three sets of stimuli. After being analyzed using MDS, selected stimuli were then assessed again in a second experiment to validate their robust valence and arousal distinctions. The second experiment was conducted with 34 subjects to validate 40 of the best stimuli from experiment 1. It was found that mental imagery stimuli can produce a reliable affective response for the dimensions of valence and arousal and that MDS can be an effective tool for stimuli development.

Automatic and deliberate affective associations with sexual stimuli in women with lifelong vaginismus before and after therapist-aided exposure treatment.

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Melles, Reinhilde J; ter Kuile, Moniek M; Dewitte, Marieke; van Lankveld, Jacques J D M; Brauer, Marieke; de Jong, Peter J

2014-03-01

The intense fear response to vaginal penetration in women with lifelong vaginismus, who have never been able to experience coitus, may reflect negative automatic and deliberate appraisals of vaginal penetration stimuli which might be modified by exposure treatment. The aim of this study is to examine whether (i) sexual stimuli elicit relatively strong automatic and deliberate threat associations in women with vaginismus, as well as relatively negative automatic and deliberate global affective associations, compared with symptom-free women; and (ii) these automatic and more deliberate attitudes can be modified by therapist-aided exposure treatment. A single target Implicit Association Test (st-IAT) was used to index automatic threat associations, and an Affective Simon Task (AST) to index global automatic affective associations. Participants were women with lifelong vaginismus (N = 68) and women without sexual problems (N = 70). The vaginismus group was randomly allocated to treatment (n = 34) and a waiting list control condition (n = 34). Indices of automatic threat were obtained by the st-IAT and automatic global affective associations by the AST, visual analogue scales (VAS) were used to assess deliberate appraisals of the sexual pictures (fear and global positive affect). More deliberate fear and less global positive affective associations with sexual stimuli were found in women with vaginismus. Following therapist-aided exposure treatment, the strength of fear was strongly reduced, whereas global positive affective associations were strengthened. Automatic associations did not differ between women with and without vaginismus and did not change following treatment. Relatively stronger negative (threat or global affect) associations with sexual stimuli in vaginismus appeared restricted to the deliberate level. Therapist-aided exposure treatment was effective in reducing subjective fear of sexual penetration stimuli and led to more global positive affective

Functional neuroimaging studies in addiction: multisensory drug stimuli and neural cue reactivity.

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Yalachkov, Yavor; Kaiser, Jochen; Naumer, Marcus J

2012-02-01

Neuroimaging studies on cue reactivity have substantially contributed to the understanding of addiction. In the majority of studies drug cues were presented in the visual modality. However, exposure to conditioned cues in real life occurs often simultaneously in more than one sensory modality. Therefore, multisensory cues should elicit cue reactivity more consistently than unisensory stimuli and increase the ecological validity and the reliability of brain activation measurements. This review includes the data from 44 whole-brain functional neuroimaging studies with a total of 1168 subjects (812 patients and 356 controls). Correlations between neural cue reactivity and clinical covariates such as craving have been reported significantly more often for multisensory than unisensory cues in the motor cortex, insula and posterior cingulate cortex. Thus, multisensory drug cues are particularly effective in revealing brain-behavior relationships in neurocircuits of addiction responsible for motivation, craving awareness and self-related processing. Copyright © 2011 Elsevier Ltd. All rights reserved.

Auditory Motion Elicits a Visual Motion Aftereffect.

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Berger, Christopher C; Ehrsson, H Henrik

2016-01-01

The visual motion aftereffect is a visual illusion in which exposure to continuous motion in one direction leads to a subsequent illusion of visual motion in the opposite direction. Previous findings have been mixed with regard to whether this visual illusion can be induced cross-modally by auditory stimuli. Based on research on multisensory perception demonstrating the profound influence auditory perception can have on the interpretation and perceived motion of visual stimuli, we hypothesized that exposure to auditory stimuli with strong directional motion cues should induce a visual motion aftereffect. Here, we demonstrate that horizontally moving auditory stimuli induced a significant visual motion aftereffect-an effect that was driven primarily by a change in visual motion perception following exposure to leftward moving auditory stimuli. This finding is consistent with the notion that visual and auditory motion perception rely on at least partially overlapping neural substrates.

Auditory Motion Elicits a Visual Motion Aftereffect

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Christopher C. Berger

2016-12-01

Full Text Available The visual motion aftereffect is a visual illusion in which exposure to continuous motion in one direction leads to a subsequent illusion of visual motion in the opposite direction. Previous findings have been mixed with regard to whether this visual illusion can be induced cross-modally by auditory stimuli. Based on research on multisensory perception demonstrating the profound influence auditory perception can have on the interpretation and perceived motion of visual stimuli, we hypothesized that exposure to auditory stimuli with strong directional motion cues should induce a visual motion aftereffect. Here, we demonstrate that horizontally moving auditory stimuli induced a significant visual motion aftereffect—an effect that was driven primarily by a change in visual motion perception following exposure to leftward moving auditory stimuli. This finding is consistent with the notion that visual and auditory motion perception rely on at least partially overlapping neural substrates.

Genomic Signatures of Reinforcement

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Austin G. Garner

2018-04-01

Full Text Available Reinforcement is the process by which selection against hybridization increases reproductive isolation between taxa. Much research has focused on demonstrating the existence of reinforcement, yet relatively little is known about the genetic basis of reinforcement or the evolutionary conditions under which reinforcement can occur. Inspired by reinforcement’s characteristic phenotypic pattern of reproductive trait divergence in sympatry but not in allopatry, we discuss whether reinforcement also leaves a distinct genomic pattern. First, we describe three patterns of genetic variation we expect as a consequence of reinforcement. Then, we discuss a set of alternative processes and complicating factors that may make the identification of reinforcement at the genomic level difficult. Finally, we consider how genomic analyses can be leveraged to inform if and to what extent reinforcement evolved in the face of gene flow between sympatric lineages and between allopatric and sympatric populations of the same lineage. Our major goals are to understand if genome scans for particular patterns of genetic variation could identify reinforcement, isolate the genetic basis of reinforcement, or infer the conditions under which reinforcement evolved.

Genomic Signatures of Reinforcement

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Goulet, Benjamin E.

2018-01-01

Reinforcement is the process by which selection against hybridization increases reproductive isolation between taxa. Much research has focused on demonstrating the existence of reinforcement, yet relatively little is known about the genetic basis of reinforcement or the evolutionary conditions under which reinforcement can occur. Inspired by reinforcement’s characteristic phenotypic pattern of reproductive trait divergence in sympatry but not in allopatry, we discuss whether reinforcement also leaves a distinct genomic pattern. First, we describe three patterns of genetic variation we expect as a consequence of reinforcement. Then, we discuss a set of alternative processes and complicating factors that may make the identification of reinforcement at the genomic level difficult. Finally, we consider how genomic analyses can be leveraged to inform if and to what extent reinforcement evolved in the face of gene flow between sympatric lineages and between allopatric and sympatric populations of the same lineage. Our major goals are to understand if genome scans for particular patterns of genetic variation could identify reinforcement, isolate the genetic basis of reinforcement, or infer the conditions under which reinforcement evolved. PMID:29614048

Enhancement of a visual reinforcer by D-amphetamine and nicotine in adult rats: relation to habituation and food restriction.

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Wright, Jennifer M; Ren, Suelynn; Constantin, Annie; Clarke, Paul B S

2018-03-01

Nicotine and D-amphetamine can strengthen reinforcing effects of unconditioned visual stimuli. We investigated whether these reinforcement-enhancing effects reflect a slowing of stimulus habituation and depend on food restriction. Adult male rats pressed an active lever to illuminate a cue light during daily 60-min sessions. Depending on the experiment, rats were challenged with fixed or varying doses of D-amphetamine (0.25-2 mg/kg IP) and nicotine (0.025-0.2 mg/kg SC) or with the tobacco constituent norharman (0.03-10 μg/kg IV). Experiment 1 tested for possible reinforcement-enhancing effects of D-amphetamine and norharman. Experiment 2 investigated whether nicotine and amphetamine inhibited the spontaneous within-session decline in lever pressing. Experiment 3 assessed the effects of food restriction. Amphetamine (0.25-1 mg/kg) and nicotine (0.1 mg/kg) increased active lever pressing specifically (two- to threefold increase). The highest doses of nicotine and amphetamine also affected inactive lever responding (increase and decrease, respectively). With the visual reinforcer omitted, responding was largely extinguished. Neither drug appeared to slow habituation, as assessed by the within-session decline in lever pressing, and reinforcement-enhancing effects still occurred if the drugs were given after this decline had occurred. Food restriction enhanced the reinforcement-enhancing effect of amphetamine but not that of nicotine. Responding remained goal-directed after several weeks of testing. Low doses of D-amphetamine and nicotine produced reinforcement enhancement even in free-feeding subjects, independent of the spontaneous within-session decline in responding. Reinforcement enhancement by amphetamine, but not nicotine, was enhanced by concurrent subchronic food restriction.

Heart rate responses provide an objective evaluation of human disturbance stimuli in breeding birds.

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Ellenberg, Ursula; Mattern, Thomas; Seddon, Philip J

2013-01-01

Intuition is a poor guide for evaluating the effects of human disturbance on wildlife. Using the endangered Yellow-eyed penguin, Megadyptes antipodes, as an example, we show that heart rate responses provide an objective tool to evaluate human disturbance stimuli and encourage the wider use of this simple and low-impact approach. Yellow-eyed penguins are a flagship species for New Zealand's wildlife tourism; however, unregulated visitor access has recently been associated with reduced breeding success and lower first year survival. We measured heart rate responses of Yellow-eyed penguins via artificial eggs to evaluate a range of human stimuli regularly occurring at their breeding sites. We found the duration of a stimulus to be the most important factor, with elevated heart rate being sustained while a person remained within sight. Human activity was the next important component; a simulated wildlife photographer, crawling slowly around during his stay, elicited a significantly higher heart rate response than an entirely motionless human spending the same time at the same distance. Stimuli we subjectively might perceive as low impact, such as the careful approach of a 'wildlife photographer', resulted in a stronger response than a routine nest-check that involved lifting a bird up to view nest contents. A single, slow-moving human spending 20 min within 2 m from the nest may provoke a response comparable to that of 10 min handling a bird for logger deployment. To reduce cumulative impact of disturbance, any human presence in the proximity of Yellow-eyed penguins needs to be kept at a minimum. Our results highlight the need for objective quantification of the effects of human disturbance in order to provide a sound basis for guidelines to manage human activity around breeding birds.

Virtual reality stimuli for force platform posturography.

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Tossavainen, Timo; Juhola, Martti; Ilmari, Pyykö; Aalto, Heikki; Toppila, Esko

2002-01-01

People relying much on vision in the control of posture are known to have an elevated risk of falling. Dependence on visual control is an important parameter in the diagnosis of balance disorders. We have previously shown that virtual reality methods can be used to produce visual stimuli that affect balance, but suitable stimuli need to be found. In this study the effect of six different virtual reality stimuli on the balance of 22 healthy test subjects was evaluated using force platform posturography. According to the tests two of the stimuli have a significant effect on balance.

Precise Control over the Rheological Behavior of Associating Stimuli-Responsive Block Copolymer Gels

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Jérémy Brassinne

2015-12-01

Full Text Available “Smart” materials have considerably evolved over the last few years for specific applications. They rely on intelligent macromolecules or (supra-molecular motifs to adapt their structure and properties in response to external triggers. Here, a supramolecular stimuli-responsive polymer gel is constructed from heterotelechelic double hydrophilic block copolymers that incorporate thermo-responsive sequences. These macromolecular building units are synthesized via a three-step controlled radical copolymerization and then hierarchically assembled to yield coordination micellar hydrogels. The dynamic mechanical properties of this particular class of materials are studied in shear flow and finely tuned via temperature changes. Notably, rheological experiments show that structurally reinforcing the micellar network nodes leads to precise tuning of the viscoelastic response and yield behavior of the material. Hence, they constitute promising candidates for specific applications, such as mechano-sensors.

Structural Behavior of Concrete Beams Reinforced with Basalt Fiber Reinforced Polymer (BFRP) Bars

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Ovitigala, Thilan

The main challenge for civil engineers is to provide sustainable, environmentally friendly and financially feasible structures to the society. Finding new materials such as fiber reinforced polymer (FRP) material that can fulfill the above requirements is a must. FRP material was expensive and it was limited to niche markets such as space shuttles and air industry in the 1960s. Over the time, it became cheaper and spread to other industries such as sporting goods in the 1980-1990, and then towards the infrastructure industry. Design and construction guidelines are available for carbon fiber reinforced polymer (CFRP), aramid fiber reinforced polymer (AFRP) and glass fiber reinforced polymer (GFRP) and they are currently used in structural applications. Since FRP is linear elastic brittle material, design guidelines for the steel reinforcement are not valid for FRP materials. Corrosion of steel reinforcement affects the durability of the concrete structures. FRP reinforcement is identified as an alternative to steel reinforcement in corrosive environments. Although basalt fiber reinforced polymer (BFRP) has many advantages over other FRP materials, but limited studies have been done. These studies didn't include larger BFRP bar diameters that are mostly used in practice. Therefore, larger beam sizes with larger BFRP reinforcement bar diameters are needed to investigate the flexural and shear behavior of BFRP reinforced concrete beams. Also, shear behavior of BFRP reinforced concrete beams was not yet studied. Experimental testing of mechanical properties and bond strength of BFRP bars and flexural and shear behavior of BFRP reinforced concrete beams are needed to include BFRP reinforcement bars in the design codes. This study mainly focuses on the use of BFRP bars as internal reinforcement. The test results of the mechanical properties of BFRP reinforcement bars, the bond strength of BFRP reinforcement bars, and the flexural and shear behavior of concrete beams

Predicting dynamic range and intensity discrimination for electrical pulse-train stimuli using a stochastic auditory nerve model: the effects of stimulus noise.

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Xu, Yifang; Collins, Leslie M

2005-06-01

This work investigates dynamic range and intensity discrimination for electrical pulse-train stimuli that are modulated by noise using a stochastic auditory nerve model. Based on a hypothesized monotonic relationship between loudness and the number of spikes elicited by a stimulus, theoretical prediction of the uncomfortable level has previously been determined by comparing spike counts to a fixed threshold, Nucl. However, no specific rule for determining Nucl has been suggested. Our work determines the uncomfortable level based on the excitation pattern of the neural response in a normal ear. The number of fibers corresponding to the portion of the basilar membrane driven by a stimulus at an uncomfortable level in a normal ear is related to Nucl at an uncomfortable level of the electrical stimulus. Intensity discrimination limens are predicted using signal detection theory via the probability mass function of the neural response and via experimental simulations. The results show that the uncomfortable level for pulse-train stimuli increases slightly as noise level increases. Combining this with our previous threshold predictions, we hypothesize that the dynamic range for noise-modulated pulse-train stimuli should increase with additive noise. However, since our predictions indicate that intensity discrimination under noise degrades, overall intensity coding performance may not improve significantly.

Reward-associated stimuli capture the eyes in spite of strategic attentional set.

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Hickey, Clayton; van Zoest, Wieske

2013-11-01

Theories of reinforcement learning have proposed that the association of reward to visual stimuli may cause these objects to become fundamentally salient and thus attention-drawing. A number of recent studies have investigated the oculomotor correlates of this reward-priming effect, but there is some ambiguity in this literature regarding the involvement of top-down attentional set. Existing paradigms tend to create a situation where participants are actively looking for a reward-associated stimulus before subsequently showing that this selective bias sustains when it no longer has strategic purpose. This perseveration of attentional set is potentially different in nature than the direct impact of reward proposed by theory. Here we investigate the effect of reward on saccadic selection in a paradigm where strategic attentional set is decoupled from the effect of reward. We find that during search for a uniquely oriented target, the receipt of reward following selection of a target characterized by an irrelevant unique color causes subsequent stimuli characterized by this color to be preferentially selected. Importantly, this occurs regardless of whether the color characterizes the target or distractor. Other analyses demonstrate that only features associated with correct selection of the target prime the target representation, and that the magnitude of this effect can be predicted by variability in saccadic indices of feedback processing. These results add to a growing literature demonstrating that reward guides visual selection, often in spite of our strategic efforts otherwise. Copyright © 2013 Elsevier B.V. All rights reserved.

Pleasurable music affects reinforcement learning according to the listener

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Gold, Benjamin P.; Frank, Michael J.; Bogert, Brigitte; Brattico, Elvira

2013-01-01

Mounting evidence links the enjoyment of music to brain areas implicated in emotion and the dopaminergic reward system. In particular, dopamine release in the ventral striatum seems to play a major role in the rewarding aspect of music listening. Striatal dopamine also influences reinforcement learning, such that subjects with greater dopamine efficacy learn better to approach rewards while those with lesser dopamine efficacy learn better to avoid punishments. In this study, we explored the practical implications of musical pleasure through its ability to facilitate reinforcement learning via non-pharmacological dopamine elicitation. Subjects from a wide variety of musical backgrounds chose a pleasurable and a neutral piece of music from an experimenter-compiled database, and then listened to one or both of these pieces (according to pseudo-random group assignment) as they performed a reinforcement learning task dependent on dopamine transmission. We assessed musical backgrounds as well as typical listening patterns with the new Helsinki Inventory of Music and Affective Behaviors (HIMAB), and separately investigated behavior for the training and test phases of the learning task. Subjects with more musical experience trained better with neutral music and tested better with pleasurable music, while those with less musical experience exhibited the opposite effect. HIMAB results regarding listening behaviors and subjective music ratings indicate that these effects arose from different listening styles: namely, more affective listening in non-musicians and more analytical listening in musicians. In conclusion, musical pleasure was able to influence task performance, and the shape of this effect depended on group and individual factors. These findings have implications in affective neuroscience, neuroaesthetics, learning, and music therapy. PMID:23970875

Are We Afraid of Different Categories of Stimuli in Identical Ways? Evidence from Skin Conductance Responses

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Yang, Jiongjiong

2013-01-01

Studies have shown that emotional pictures attract more attention than neutral pictures, and pictures of living stimuli have similar advantage in driving attention (vs. nonliving). However, factors of emotion, category and picture context are usually mixed so that whether living and nonliving categories elicit different skin conductance (SC) responses, in both conscious and unconscious conditions, remains to be clarified. In this study, participants were presented with negative and neutral pictures denoting different living and nonliving concepts in conscious (Experiments 1 and 2) and unconscious conditions (40ms, Experiment 3) when their SC responses were measured. The picture context was manipulated in Experiments 2 and 3 as half including human-related information. In three experiments, the emotional levels of different categories were matched in different and identical cohorts of participants. The results showed that living pictures in a negative, high-arousing dimension elicited stronger SC responses than nonliving pictures. When nonhuman animals and inanimate objects were compared, the increased SC responses to animals was obtained only for negative pictures without human contexts in the conscious condition, but regardless of human context in the unconscious condition. These results suggested that contextual information and level of conscious awareness are important to modulate the animate advantage in emotional processing. PMID:24039879

Adapting without reinforcement.

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Kheifets, Aaron; Gallistel, C Randy

2012-11-01

Our data rule out a broad class of behavioral models in which behavioral change is guided by differential reinforcement. To demonstrate this, we showed that the number of reinforcers missed before the subject shifted its behavior was not sufficient to drive behavioral change. What's more, many subjects shifted their behavior to a more optimal strategy even when they had not yet missed a single reinforcer. Naturally, differential reinforcement cannot be said to drive a process that shifts to accommodate to new conditions so adeptly that it doesn't miss a single reinforcer: it would have no input on which to base this shift.

Investigations of timing during the schedule and reinforcement intervals with wheel-running reinforcement.

Science.gov (United States)

Belke, Terry W; Christie-Fougere, Melissa M

2006-11-01

Across two experiments, a peak procedure was used to assess the timing of the onset and offset of an opportunity to run as a reinforcer. The first experiment investigated the effect of reinforcer duration on temporal discrimination of the onset of the reinforcement interval. Three male Wistar rats were exposed to fixed-interval (FI) 30-s schedules of wheel-running reinforcement and the duration of the opportunity to run was varied across values of 15, 30, and 60s. Each session consisted of 50 reinforcers and 10 probe trials. Results showed that as reinforcer duration increased, the percentage of postreinforcement pauses longer than the 30-s schedule interval increased. On probe trials, peak response rates occurred near the time of reinforcer delivery and peak times varied with reinforcer duration. In a second experiment, seven female Long-Evans rats were exposed to FI 30-s schedules leading to 30-s opportunities to run. Timing of the onset and offset of the reinforcement period was assessed by probe trials during the schedule interval and during the reinforcement interval in separate conditions. The results provided evidence of timing of the onset, but not the offset of the wheel-running reinforcement period. Further research is required to assess if timing occurs during a wheel-running reinforcement period.

Enhancing corrosion resistance of reinforced concrete structures with hybrid fiber reinforced concrete

International Nuclear Information System (INIS)

Blunt, J.; Jen, G.; Ostertag, C.P.

2015-01-01

Highlights: • Reinforced concrete beams were subjected to cyclic flexural loading. • Hybrid fiber reinforced composites were effective in reducing corrosion rates. • Crack resistance due to fibers increased corrosion resistance of steel rebar. • Galvanic corrosion measurements underestimated corrosion rates. • Polarization resistance measurements predicted mass loss more accurately. - Abstract: Service loads well below the yield strength of steel reinforcing bars lead to cracking of reinforced concrete. This paper investigates whether the crack resistance of Hybrid Fiber Reinforced Concrete (HyFRC) reduces the corrosion rate of steel reinforcing bars in concrete after cyclic flexural loading. The reinforcing bars were extracted to examine their surface for corrosion and compare microcell and macrocell corrosion mass loss estimates against direct gravimetric measurements. A delay in corrosion initiation and lower active corrosion rates were observed in the HyFRC beam specimens when compared to reinforced specimens containing plain concrete matrices cycled at the same flexural load

Instructed fear stimuli bias visual attention

NARCIS (Netherlands)

Deltomme, Berre; Mertens, G.; Tibboel, Helen; Braem, Senne

We investigated whether stimuli merely instructed to be fear-relevant can bias visual attention, even when the fear relation was never experienced before. Participants performed a dot-probe task with pictures of naturally fear-relevant (snake or spider) or -irrelevant (bird or butterfly) stimuli.

Attribute amnesia is greatly reduced with novel stimuli

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Weijia Chen

2017-11-01

Full Text Available Attribute amnesia is the counterintuitive phenomenon where observers are unable to report a salient aspect of a stimulus (e.g., its colour or its identity immediately after the stimulus was presented, despite both attending to and processing the stimulus. Almost all previous attribute amnesia studies used highly familiar stimuli. Our study investigated whether attribute amnesia would also occur for unfamiliar stimuli. We conducted four experiments using stimuli that were highly familiar (colours or repeated animal images or that were unfamiliar to the observers (unique animal images. Our results revealed that attribute amnesia was present for both sets of familiar stimuli, colour (p < .001 and repeated animals (p = .001; but was greatly attenuated, and possibly eliminated, when the stimuli were unique animals (p = .02. Our data shows that attribute amnesia is greatly reduced for novel stimuli.

Repeated elicitation of the acoustic startle reflex leads to sensitisation in subsequent avoidance behaviour and induces fear conditioning

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Janik Vincent M

2011-04-01

Full Text Available Abstract Background Autonomous reflexes enable animals to respond quickly to potential threats, prevent injury and mediate fight or flight responses. Intense acoustic stimuli with sudden onsets elicit a startle reflex while stimuli of similar intensity but with longer rise times only cause a cardiac defence response. In laboratory settings, habituation appears to affect all of these reflexes so that the response amplitude generally decreases with repeated exposure to the stimulus. The startle reflex has become a model system for the study of the neural basis of simple learning processes and emotional processing and is often used as a diagnostic tool in medical applications. However, previous studies did not allow animals to avoid the stimulus and the evolutionary function and long-term behavioural consequences of repeated startling remain speculative. In this study we investigate the follow-up behaviour associated with the startle reflex in wild-captured animals using an experimental setup that allows individuals to exhibit avoidance behaviour. Results We present evidence that repeated elicitation of the acoustic startle reflex leads to rapid and pronounced sensitisation of sustained spatial avoidance behaviour in grey seals (Halichoerus grypus. Animals developed rapid flight responses, left the exposure pool and showed clear signs of fear conditioning. Once sensitised, seals even avoided a known food source that was close to the sound source. In contrast, animals exposed to non-startling (long rise time stimuli of the same maximum sound pressure habituated and flight responses waned or were absent from the beginning. The startle threshold of grey seals expressed in units of sensation levels was comparable to thresholds reported for other mammals (93 dB. Conclusions Our results demonstrate that the acoustic startle reflex plays a crucial role in mediating flight responses and strongly influences the motivational state of an animal beyond a short

Behavioral sensitivity of Japanese children with and without ADHD to changing reinforcer availability: an experimental study using signal detection methodology.

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Furukawa, Emi; Shimabukuro, Shizuka; Alsop, Brent; Tripp, Gail

2017-09-25

Most research on motivational processes in attention deficit hyperactivity disorder (ADHD) has been undertaken in Western Europe and North America. The extent to which these findings apply to other cultural groups is unclear. The current study evaluated the behavioral sensitivity of Japanese children with and without ADHD to changing reward availability. Forty-one school-aged children, 19 diagnosed with DSM-IV ADHD, completed a signal-detection task in which correct discriminations between two stimuli were associated with different reinforcement frequencies. The response alternative associated with the higher rate of reinforcement switched twice during the task without warning. Both groups of children developed an initial bias toward the more frequently reinforced response alternative. When the reward contingencies switched the response allocation (bias) of the control group children followed suit. The response bias scores of the children with ADHD did not, suggesting impaired tracking of reward availability over time. Japanese children with ADHD adjust their behavioral responses to changing reinforcer availability less than their typically developing peers. This is not explained by poor attention to task or a lack of sensitivity to reward. The current results are consistent with altered sensitivity to changing reward contingencies identified in non-Japanese samples of children with ADHD. Irrespective of their country of origin, children with ADHD will likely benefit from behavioral expectations and reinforcement contingencies being made explicit together with high rates of reinforcement for appropriate behaviors.

Theoretical and numerical analysis of reinforced concrete beams with confinement reinforcement

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R. G. Delalibera

Full Text Available This paper discusses the use of confinement in over-reinforced concrete beams. This reinforcement consists of square stirrups, placed in the compression zone of the beam cross-section, in order to improve its ductility. A parametric numerical study is initially performed, using a finite element computational program that considers the material nonlinearities and the confinement effect. To investigate the influence of the transverse reinforcing ratio on the beam ductility, an experimental program was also conducted. Four over-reinforced beams were tested; three beam specimens with additional transverse reinforcement to confine the beams, and one without it. All specimens were fabricated with a concrete designed for a compressive strength of 25 MPa. The experimental results show that the post-peak ductility factor is proportional to the confining reinforcement ratio, however the same is not observed for the pre-peak ductility factor, which varied randomly with changes in the confining reinforcement ratio. It was also observed from the experiments that the confinement effect tends to be smaller close to the beam neutral axis.

Stimuli-Regulated Smart Polymeric Systems for Gene Therapy

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Ansuja Pulickal Mathew

2017-04-01

Full Text Available The physiological condition of the human body is a composite of different environments, each with its own parameters that may differ under normal, as well as diseased conditions. These environmental conditions include factors, such as pH, temperature and enzymes that are specific to a type of cell, tissue or organ or a pathological state, such as inflammation, cancer or infection. These conditions can act as specific triggers or stimuli for the efficient release of therapeutics at their destination by overcoming many physiological and biological barriers. The efficacy of conventional treatment modalities can be enhanced, side effects decreased and patient compliance improved by using stimuli-responsive material that respond to these triggers at the target site. These stimuli or triggers can be physical, chemical or biological and can be internal or external in nature. Many smart/intelligent stimuli-responsive therapeutic gene carriers have been developed that can respond to either internal stimuli, which may be normally present, overexpressed or present in decreased levels, owing to a disease, or to stimuli that are applied externally, such as magnetic fields. This review focuses on the effects of various internal stimuli, such as temperature, pH, redox potential, enzymes, osmotic activity and other biomolecules that are present in the body, on modulating gene expression by using stimuli-regulated smart polymeric carriers.

Preparation and properties of in-situ growth of carbon nanotubes reinforced hydroxyapatite coating for carbon/carbon composites

Energy Technology Data Exchange (ETDEWEB)

Liu, Shoujie, E-mail: jlliushoujie@126.com; Li, Hejun, E-mail: lihejun@nwpu.edu.cn; Su, Yangyang, E-mail: suyangyang@mail.nwpu.edu.cn; Guo, Qian, E-mail: 1729299905@163.com; Zhang, Leilei, E-mail: zhangleilei@nwpu.edu.cn

2017-01-01

Carbon nanotubes (CNTs) possess excellent mechanical properties for their role playing in reinforcement as imparting strength to brittle hydroxyapatite (HA) bioceramic coating. However, there are few reports relating to the in-situ grown carbon nanotubes reinforced hydroxyapatite (CNTs-HA) coating. Here we demonstrate the potential application in reinforcing biomaterials by an attempt to use in-situ grown of CNTs strengthen HA coating, using a combined method composited of injection chemical vapor deposition (ICVD) and pulsed electrodeposition. The microstructure, phases and chemical compositions of CNTs-HA coatings were characterized by various advanced methods. The scanning electron microscopy (SEM) images indicated that CNTs-HA coatings avoided the inhomogeneous dispersion of CNTs inside HA coating. The result show that the interfacial shear strength between CNTs-HA coating and the C/C composite matrix reaches to 12.86 ± 1.43 MPa. Potenitodynamic polarization and electrochemical impedance spectroscopy (EIS) studies show that the content of CNTs affects the corrosion resistance of CNTs-HA coating. Cell culturing and simulated body fluid test elicit the biocompatibility with living cells and bioactivity of CNTs-HA coatings, respectively. - Highlights: • A novel bioceramic composite coating of hydroxyapatite reinforced with in-situ grown carbon nanotubes was fabricated. • The doping of carbon nanotubes had almost no impact on the biocompatibility of hydroxyapatite coatings. • The doping of carbon nanotubes improved corrosion resistance of hydroxyapatite coatings in simulated human body solution.

Striatal intrinsic reinforcement signals during recognition memory: relationship to response bias and dysregulation in schizophrenia

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Daniel H Wolf

2011-12-01

Full Text Available Ventral striatum (VS is a critical brain region for reinforcement learning and motivation, and VS hypofunction is implicated in psychiatric disorders including schizophrenia. Providing rewards or performance feedback has been shown to activate VS. Intrinisically motivated subjects performing challenging cognitive tasks are likely to engage reinforcement circuitry even in the absence of external feedback or incentives. However, such intrinsic reinforcement responses have received little attention, have not been examined in relation to behavioral performance, and have not been evaluated for impairment in neuropsychiatric disorders such as schizophrenia. Here we used fMRI to examine a challenging 'old' vs. 'new' visual recognition task in healthy subjects and patients with schizophrenia. Targets were unique fractal stimuli previously presented as salient distractors in a visual oddball task, producing incidental memory encoding. Based on the prediction error theory of reinforcement learning, we hypothesized that correct target recognition would activate VS in controls, and that this activation would be greater in subjects with lower expectation of responding correctly as indexed by a more conservative response bias. We also predicted these effects would be reduced in patients with schizophrenia. Consistent with these predictions, controls activated VS and other reinforcement processing regions during correct recognition, with greater VS activation in those with a more conservative response bias. Patients did not show either effect, with significant group differences suggesting hyporesponsivity in patients to internally-generated feedback. These findings highlight the importance of accounting for intrinsic motivation and reward when studying cognitive tasks, and add to growing evidence of reward circuit dysfunction in schizophrenia that may impact cognition and function.

Perceptual mapping of chemesthetic stimuli in naïve assessors.

Science.gov (United States)

Byrnes, Nadia; Nestrud, Michael A; Hayes, John E

2015-06-01

Chemesthetic compounds, responsible for sensations such as burning, cooling, and astringency, are difficult stimuli to work with, especially when the evaluation task requires retasting. Here, we developed a protocol by which chemesthetic compounds can be assessed using sorting. We compared the performance of two cohorts of untrained assessors on this task, one with nose clips and the other without. Similarity matrices were analyzed using multidimensional scaling (MDS) to produce perceptual maps for the two cohorts. Overall, the groupings from the nose open cohort tended to follow a biological basis, consistent with previous findings that suggest compounds that activate a common receptor will elicit similar sensations. The nose-open and nose-pinched cohorts generated significantly different maps. The nose-pinched cohort had a higher variance in the MDS solution than the nose-open group. While the nose-open cohort generated seven clusters, the nose-pinched cohort generated only two clusters, seemingly based on the ready identification of chemesthetic sensations or not. There was less consensus regarding the attributes used to describe the samples in the nose-pinched cohort than in the nose-open cohort as well, as this cohort collectively generated more attributes but fewer were significant in regression.

Axial Compression Tests on Corroded Reinforced Concrete Columns Consolidated with Fibre Reinforced Polymers

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Bin Ding

2017-06-01

Full Text Available Reinforced concrete structure featured by strong bearing capacity, high rigidity, good integrity, good fire resistance, and extensive applicability occupies a mainstream position in contemporary architecture. However, with the development of social economy, people need higher requirements on architectural structure; durability, especially, has been extensively researched. Because of the higher requirement on building material, ordinary reinforced concrete structure has not been able to satisfy the demand. As a result, some new materials and structures have emerged, for example, fibre reinforced polymers. Compared to steel reinforcement, fibre reinforced polymers have many advantages, such as high tensile strength, good durability, good shock absorption, low weight, and simple construction. The application of fibre reinforced polymers in architectural structure can effectively improve the durability of the concrete structure and lower the maintenance, reinforcement, and construction costs in severe environments. Based on the concepts of steel tube concrete, fibre reinforced composite material confined concrete, and fibre reinforced composite material tubed concrete, this study proposes a novel composite structure, i.e., fibre reinforced composite material and steel tube concrete composite structure. The structure was developed by pasting fibre around steel tube concrete and restraining core concrete using fibre reinforced composite material and steel tubes. The bearing capacity and ultimate deformation capacity of the structure was tested using column axial compression test.

A comparison of five methodological variants of emoji questionnaires for measuring product elicited emotional associations: An application with seafood among Chinese consumers.

Science.gov (United States)

Ares, Gastón; Jaeger, Sara R

2017-09-01

Product insights beyond hedonic responses are increasingly sought and include emotional associations. Various word-based questionnaires for direct measurement exist and an emoji variant was recently proposed. Herein, emotion words are replaced with emoji conveying a range of emotions. Further assessment of emoji questionnaires is needed to establish their relevance in food-related consumer research. Methodological research contributes hereto and in the present research the effects of question wording and response format are considered. Specifically, a web study was conducted with Chinese consumers (n=750) using four seafood names as stimuli (mussels, lobster, squid and abalone). Emotional associations were elicited using 33 facial emoji. Explicit reference to "how would you feel?" in the question wording changed product emoji profiles minimally. Consumers selected only a few emoji per stimulus when using CATA (check-all-that-apply) questions, and layout of the CATA question had only a small impact on responses. A comparison of CATA questions with forced yes/no questions and RATA (rate-all-that-apply) questions revealed an increase in frequency of emoji use for yes/no questions, but not a corresponding improvement in sample discrimination. For the stimuli in this research, which elicited similar emotional associations, RATA was probably the best methodological choice, with 8.5 emoji being used per stimulus, on average, and increased sample discrimination relative to CATA (12% vs. 6-8%). The research provided additional support for the potential of emoji surveys as a method for measurement of emotional associations to foods and beverages and began contributing to development of guidelines for implementation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Recall and recognition hypermnesia for Socratic stimuli.

Science.gov (United States)

Kazén, Miguel; Solís-Macías, Víctor M

2016-01-01

In two experiments, we investigate hypermnesia, net memory improvements with repeated testing of the same material after a single study trial. In the first experiment, we found hypermnesia across three trials for the recall of word solutions to Socratic stimuli (dictionary-like definitions of concepts) replicating Erdelyi, Buschke, and Finkelstein and, for the first time using these materials, for their recognition. In the second experiment, we had two "yes/no" recognition groups, a Socratic stimuli group presented with concrete and abstract verbal materials and a word-only control group. Using signal detection measures, we found hypermnesia for concrete Socratic stimuli-and stable performance for abstract stimuli across three recognition tests. The control group showed memory decrements across tests. We interpret these findings with the alternative retrieval pathways (ARP) hypothesis, contrasting it with alternative theories of hypermnesia, such as depth of processing, generation and retrieve-recognise. We conclude that recognition hypermnesia for concrete Socratic stimuli is a reliable phenomenon, which we found in two experiments involving both forced-choice and yes/no recognition procedures.

Stimuli-Responsive Liposomes for Controlled Drug Delivery

KAUST Repository

Li, Wengang

2014-09-01

Liposomes are promising drug delivery vesicles due to their biodegradibility, large volume and biocompatibility towards both hydrophilic and hydrophobic drugs. They suffer, however, from poor stability which limits their use in controlled delivery applications. Herein, a novel method was devised for modification of liposomes with small molecules, polymers or nanoparticles to afford stimuli responsive systems that release on demand and stay relatively stable in the absence of the trigger.. This dissertation discusses thermosensitive, pH sensitive, light sensitive and magnetically triggered liposomes that have been prepared for controlled drug delivery application. RAFT polymerization was utilized for the preparation of thermosensitive liposomes (Cholesterol-PNIPAm) and acid-labile liposomes (DOPE-PAA). With low Mw Cholesterol-PNIPAm, the thermosensitive liposomes proved to be effective for controlled release and decreased the cytotoxicity of PNIPAm by eliciting the polymer doses. By crosslinking the DOPE-PAA on liposome surface with acid-labile diamine linkers, DOPE-PAA liposomes were verified to be sensitive at low pH. The effects of polymer structures (linear or hyperbranched) have also been studied for the stability and release properties of liposomes. Finally, a dual-responsive Au@SPIO embedded liposome hybrid (ALHs) was prepared with light-induced “on-and-off” function by photo-thermal process (visible light) and instant release properties triggered by alternating magnetic field, respectively. The ALH system would be further applied into the cellular imaging field as MRI contrast agent.

The Interview as an Approach to Elicit Requirements

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Luz Marina Iriarte

2013-07-01

Full Text Available In many software projects requirements elicitation is incomplete or inconsistent. One issue that works for this is presented has to be with the requirements engineers use a single method to do it, which can cause a deficiency in the expected results. Among the factors contributing to the success of this stage of the life cycle is an adequate selection of the elicitation technique and other approaches needed. This article describes an experimental study to elicit requirements, in which was applied a combination of methods and techniques, and discusses the advantages of doing it this way. The results obtained allow concluding that to achieve adequate elicitation is necessary to combine several techniques and methods.

Learning Similar Actions by Reinforcement or Sensory-Prediction Errors Rely on Distinct Physiological Mechanisms.

Science.gov (United States)

Uehara, Shintaro; Mawase, Firas; Celnik, Pablo

2017-09-14

Humans can acquire knowledge of new motor behavior via different forms of learning. The two forms most commonly studied have been the development of internal models based on sensory-prediction errors (error-based learning) and success-based feedback (reinforcement learning). Human behavioral studies suggest these are distinct learning processes, though the neurophysiological mechanisms that are involved have not been characterized. Here, we evaluated physiological markers from the cerebellum and the primary motor cortex (M1) using noninvasive brain stimulations while healthy participants trained finger-reaching tasks. We manipulated the extent to which subjects rely on error-based or reinforcement by providing either vector or binary feedback about task performance. Our results demonstrated a double dissociation where learning the task mainly via error-based mechanisms leads to cerebellar plasticity modifications but not long-term potentiation (LTP)-like plasticity changes in M1; while learning a similar action via reinforcement mechanisms elicited M1 LTP-like plasticity but not cerebellar plasticity changes. Our findings indicate that learning complex motor behavior is mediated by the interplay of different forms of learning, weighing distinct neural mechanisms in M1 and the cerebellum. Our study provides insights for designing effective interventions to enhance human motor learning. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Green Software Engineering Adaption In Requirement Elicitation Process

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Umma Khatuna Jannat

2015-08-01

Full Text Available A recent technology investigates the role of concern in the environment software that is green software system. Now it is widely accepted that the green software can fit all process of software development. It is also suitable for the requirement elicitation process. Now a days software companies have used requirements elicitation techniques in an enormous majority. Because this process plays more and more important roles in software development. At the present time most of the requirements elicitation process is improved by using some techniques and tools. So that the intention of this research suggests to adapt green software engineering for the intention of existing elicitation technique and recommend suitable actions for improvement. This research being involved qualitative data. I used few keywords in my searching procedure then searched IEEE ACM Springer Elsevier Google scholar Scopus and Wiley. Find out articles which published in 2010 until 2016. Finding from the literature review Identify 15 traditional requirement elicitations factors and 23 improvement techniques to convert green engineering. Lastly The paper includes a squat review of the literature a description of the grounded theory and some of the identity issues related finding of the necessity for requirements elicitation improvement techniques.

Flexural strength using Steel Plate, Carbon Fiber Reinforced Polymer (CFRP) and Glass Fiber Reinforced Polymer (GFRP) on reinforced concrete beam in building technology

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Tarigan, Johannes; Patra, Fadel Muhammad; Sitorus, Torang

2018-03-01

Reinforced concrete structures are very commonly used in buildings because they are cheaper than the steel structures. But in reality, many concrete structures are damaged, so there are several ways to overcome this problem, by providing reinforcement with Fiber Reinforced Polymer (FRP) and reinforcement with steel plates. Each type of reinforcements has its advantages and disadvantages. In this study, researchers discuss the comparison between flexural strength of reinforced concrete beam using steel plates and Fiber Reinforced Polymer (FRP). In this case, the researchers use Carbon Fiber Reinforced Polymer (CFRP) and Glass Fiber Reinforced Polymer (GFRP) as external reinforcements. The dimension of the beams is 15 x 25 cm with the length of 320 cm. Based on the analytical results, the strength of the beam with CFRP is 1.991 times its initial, GFRP is 1.877 times while with the steel plate is 1.646 times. Based on test results, the strength of the beam with CFRP is 1.444 times its initial, GFRP is 1.333 times while the steel plate is 1.167 times. Based on these test results, the authors conclude that beam with CFRP is the best choice for external reinforcement in building technology than the others.

Perceived emotion genuineness: normative ratings for popular facial expression stimuli and the development of perceived-as-genuine and perceived-as-fake sets.

Science.gov (United States)

Dawel, Amy; Wright, Luke; Irons, Jessica; Dumbleton, Rachael; Palermo, Romina; O'Kearney, Richard; McKone, Elinor

2017-08-01

In everyday social interactions, people's facial expressions sometimes reflect genuine emotion (e.g., anger in response to a misbehaving child) and sometimes do not (e.g., smiling for a school photo). There is increasing theoretical interest in this distinction, but little is known about perceived emotion genuineness for existing facial expression databases. We present a new method for rating perceived genuineness using a neutral-midpoint scale (-7 = completely fake; 0 = don't know; +7 = completely genuine) that, unlike previous methods, provides data on both relative and absolute perceptions. Normative ratings from typically developing adults for five emotions (anger, disgust, fear, sadness, and happiness) provide three key contributions. First, the widely used Pictures of Facial Affect (PoFA; i.e., "the Ekman faces") and the Radboud Faces Database (RaFD) are typically perceived as not showing genuine emotion. Also, in the only published set for which the actual emotional states of the displayers are known (via self-report; the McLellan faces), percepts of emotion genuineness often do not match actual emotion genuineness. Second, we provide genuine/fake norms for 558 faces from several sources (PoFA, RaFD, KDEF, Gur, FacePlace, McLellan, News media), including a list of 143 stimuli that are event-elicited (rather than posed) and, congruently, perceived as reflecting genuine emotion. Third, using the norms we develop sets of perceived-as-genuine (from event-elicited sources) and perceived-as-fake (from posed sources) stimuli, matched on sex, viewpoint, eye-gaze direction, and rated intensity. We also outline the many types of research questions that these norms and stimulus sets could be used to answer.

Comparison of the influence of stimuli color on Steady-State Visual Evoked Potentials

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Richard Junior Manuel Godinez Tello

Full Text Available IntroductionThe main idea of a traditional Steady State Visually Evoked Potentials (SSVEP-BCI is the activation of commands through gaze control. For this purpose, the retina of the eye is excited by a stimulus at a certain frequency. Several studies have shown effects related to different kind of stimuli, frequencies, window lengths, techniques of feature extraction and even classification. So far, none of the previous studies has performed a comparison of performance of stimuli colors through LED technology. This study addresses precisely this important aspect and would be a great contribution to the topic of SSVEP-BCIs. Additionally, the performance of different colors at different frequencies and the visual comfort were evaluated in each case.MethodsLEDs of four different colors (red, green, blue and yellow flickering at four distinct frequencies (8, 11, 13 and 15 Hz were used. Twenty subjects were distributed in two groups performing different protocols. Multivariate Synchronization Index (MSI was the technique adopted as feature extractor.ResultsThe accuracy was gradually enhanced with the increase of the time window. From our observations, the red color provides, in most frequencies, both highest rates of accuracy and Information Transfer Rate (ITR for detection of SSVEP.ConclusionAlthough the red color has presented higher ITR, this color was turned in the less comfortable one and can even elicit epileptic responses according to the literature. For this reason, the green color is suggested as the best choice according to the proposed rules. In addition, this color has shown to be safe and accurate for an SSVEP-BCI.

Needs Elicitation for Novel Pervasive Healthcare Technology

DEFF Research Database (Denmark)

Thorpe, Julia Rosemary; Forchhammer, B. H.; Maier, Anja

2016-01-01

for pervasive healthcare technology, in which established methods for engaging users to elicit their needs can be difficult or even impossible to apply. In this paper we document our needs elicitation process in a relevant example as a method story, and present our findings and reflections on this as the key...

Cortical response tracking the conscious experience of threshold duration visual stimuli indicates visual perception is all or none

Science.gov (United States)

Sekar, Krithiga; Findley, William M.; Poeppel, David; Llinás, Rodolfo R.

2013-01-01

At perceptual threshold, some stimuli are available for conscious access whereas others are not. Such threshold inputs are useful tools for investigating the events that separate conscious awareness from unconscious stimulus processing. Here, viewing unmasked, threshold-duration images was combined with recording magnetoencephalography to quantify differences among perceptual states, ranging from no awareness to ambiguity to robust perception. A four-choice scale was used to assess awareness: “didn’t see” (no awareness), “couldn’t identify” (awareness without identification), “unsure” (awareness with low certainty identification), and “sure” (awareness with high certainty identification). Stimulus-evoked neuromagnetic signals were grouped according to behavioral response choices. Three main cortical responses were elicited. The earliest response, peaking at ∼100 ms after stimulus presentation, showed no significant correlation with stimulus perception. A late response (∼290 ms) showed moderate correlation with stimulus awareness but could not adequately differentiate conscious access from its absence. By contrast, an intermediate response peaking at ∼240 ms was observed only for trials in which stimuli were consciously detected. That this signal was similar for all conditions in which awareness was reported is consistent with the hypothesis that conscious visual access is relatively sharply demarcated. PMID:23509248

Stimuli responsive nanomaterials for controlled release applications

KAUST Repository

Li, Song; Li, Wengang; Khashab, Niveen M.

2012-01-01

applications. Stimuli-responsive nanomaterials guarantee the controlled release of cargo to a given location, at a specific time, and with an accurate amount. In this review, we have combined the major stimuli that are currently used to achieve the ultimate

Experimental analysis of reinforced concrete beams strengthened in bending with carbon fiber reinforced polymer

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M. M. VIEIRA

Full Text Available The use of carbon fiber reinforced polymer (CFRP has been widely used for the reinforcement of concrete structures due to its practicality and versatility in application, low weight, high tensile strength and corrosion resistance. Some construction companies use CFRP in flexural strengthening of reinforced concrete beams, but without anchor systems. Therefore, the aim of this study is analyze, through an experimental program, the structural behavior of reinforced concrete beams flexural strengthened by CFRP without anchor fibers, varying steel reinforcement and the amount of carbon fibers reinforcement layers. Thus, two groups of reinforced concrete beams were produced with the same geometric feature but with different steel reinforcement. Each group had five beams: one that is not reinforced with CFRP (reference and other reinforced with two, three, four and five layers of carbon fibers. Beams were designed using a computational routine developed in MAPLE software and subsequently tested in 4-point points flexural test up to collapse. Experimental tests have confirmed the effectiveness of the reinforcement, ratifying that beams collapse at higher loads and lower deformation as the amount of fibers in the reinforcing layers increased. However, the increase in the number of layers did not provide a significant increase in the performance of strengthened beams, indicating that it was not possible to take full advantage of strengthening applied due to the occurrence of premature failure mode in the strengthened beams for pullout of the cover that could have been avoided through the use of a suitable anchoring system for CFRP.

Reinforcement Schedules in a Verbal Reinforcement Combination and Renection-Impulsivity

OpenAIRE

TAMASE, Koji; UEDA, Masako

1986-01-01

It was predicted that higher proportion of the negative reinforcement "Wrong" than that of the positive reinforcement "Right" in a reinforcement combination will produce higher proportion of the correct response and this trend will be greater in reflective children than in impulsive children. From 140 kindergarten children 30 reflective and 30 impulsive children were selected and they were given a two-hole marble-dropping task. The best performance in the ratio of correct responses was obtain...

Aversive reinforcement improves visual discrimination learning in free-flying honeybees.

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Aurore Avarguès-Weber

Full Text Available BACKGROUND: Learning and perception of visual stimuli by free-flying honeybees has been shown to vary dramatically depending on the way insects are trained. Fine color discrimination is achieved when both a target and a distractor are present during training (differential conditioning, whilst if the same target is learnt in isolation (absolute conditioning, discrimination is coarse and limited to perceptually dissimilar alternatives. Another way to potentially enhance discrimination is to increase the penalty associated with the distractor. Here we studied whether coupling the distractor with a highly concentrated quinine solution improves color discrimination of both similar and dissimilar colors by free-flying honeybees. As we assumed that quinine acts as an aversive stimulus, we analyzed whether aversion, if any, is based on an aversive sensory input at the gustatory level or on a post-ingestional malaise following quinine feeding. METHODOLOGY/PRINCIPAL FINDINGS: We show that the presence of a highly concentrated quinine solution (60 mM acts as an aversive reinforcer promoting rejection of the target associated with it, and improving discrimination of perceptually similar stimuli but not of dissimilar stimuli. Free-flying bees did not use remote cues to detect the presence of quinine solution; the aversive effect exerted by this substance was mediated via a gustatory input, i.e. via a distasteful sensory experience, rather than via a post-ingestional malaise. CONCLUSION: The present study supports the hypothesis that aversion conditioning is important for understanding how and what animals perceive and learn. By using this form of conditioning coupled with appetitive conditioning in the framework of a differential conditioning procedure, it is possible to uncover discrimination capabilities that may remain otherwise unsuspected. We show, therefore, that visual discrimination is not an absolute phenomenon but can be modulated by experience.

Proposal for a Five-Step Method to Elicit Expert Judgment

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Duco Veen

2017-12-01

Full Text Available Elicitation is a commonly used tool to extract viable information from experts. The information that is held by the expert is extracted and a probabilistic representation of this knowledge is constructed. A promising avenue in psychological research is to incorporated experts’ prior knowledge in the statistical analysis. Systematic reviews on elicitation literature however suggest that it might be inappropriate to directly obtain distributional representations from experts. The literature qualifies experts’ performance on estimating elements of a distribution as unsatisfactory, thus reliably specifying the essential elements of the parameters of interest in one elicitation step seems implausible. Providing feedback within the elicitation process can enhance the quality of the elicitation and interactive software can be used to facilitate the feedback. Therefore, we propose to decompose the elicitation procedure into smaller steps with adjustable outcomes. We represent the tacit knowledge of experts as a location parameter and their uncertainty concerning this knowledge by a scale and shape parameter. Using a feedback procedure, experts can accept the representation of their beliefs or adjust their input. We propose a Five-Step Method which consists of (1 Eliciting the location parameter using the trial roulette method. (2 Provide feedback on the location parameter and ask for confirmation or adjustment. (3 Elicit the scale and shape parameter. (4 Provide feedback on the scale and shape parameter and ask for confirmation or adjustment. (5 Use the elicited and calibrated probability distribution in a statistical analysis and update it with data or to compute a prior-data conflict within a Bayesian framework. User feasibility and internal validity for the Five-Step Method are investigated using three elicitation studies.

Protein-surface interactions on stimuli-responsive polymeric biomaterials.

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Cross, Michael C; Toomey, Ryan G; Gallant, Nathan D

2016-03-04

Responsive surfaces: a review of the dependence of protein adsorption on the reversible volume phase transition in stimuli-responsive polymers. Specifically addressed are a widely studied subset: thermoresponsive polymers. Findings are also generalizable to other materials which undergo a similarly reversible volume phase transition. As of 2015, over 100,000 articles have been published on stimuli-responsive polymers and many more on protein-biomaterial interactions. Significantly, fewer than 100 of these have focused specifically on protein interactions with stimuli-responsive polymers. These report a clear trend of increased protein adsorption in the collapsed state compared to the swollen state. This control over protein interactions makes stimuli-responsive polymers highly useful in biomedical applications such as wound repair scaffolds, on-demand drug delivery, and antifouling surfaces. Outstanding questions are whether the protein adsorption is reversible with the volume phase transition and whether there is a time-dependence. A clear understanding of protein interactions with stimuli-responsive polymers will advance theoretical models, experimental results, and biomedical applications.

Affective monitoring: A generic mechanism for affect elicitation

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Hans ePhaf

2012-03-01

Full Text Available In this paper we sketch a new framework for affect elicitation, which is based on previous evolutionary and connectionist modeling and experimental work from our group. Affective monitoring is considered a local match-mismatch process within a module of the neural network. Negative affect is raised instantly by mismatches, incongruency, disfluency, novelty, incoherence, and dissonance, whereas positive affect follows from matches, congruency, fluency, familiarity, coherence, and resonance, at least when an initial mismatch can be solved quickly. Affective monitoring is considered an evolutionary-early conflict and change detection process operating at the same level as, for instance, attentional selection. It runs in parallel and imparts affective flavour to emotional behavior systems, which involve evolutionary-prepared stimuli and action tendencies related to for instance defensive, exploratory, attachment, or appetitive behavior. Positive affect is represented in the networks by high-frequency oscillations, presumably in the gamma band. Negative affect corresponds to more incoherent lower-frequency oscillations, presumably in the theta band. For affect to become conscious, large-scale synchronization of the oscillations over the network and the construction of emotional experiences are required. These constructions involve perceptions of bodily states and action tendencies, but also appraisals as well as efforts to regulate the emotion. Importantly, affective monitoring accompanies every kind of information processing, but conscious emotions, which result from the later integration of affect in a cognitive context, are much rarer events.

Emotion attribution to basic parametric static and dynamic stimuli

NARCIS (Netherlands)

Visch, V.; Goudbeek, M.B.; Cohn, J.; Nijholt, A.; Pantic, P.

2009-01-01

The following research investigates the effect of basic visual stimuli on the attribution of basic emotions by the viewer. In an empirical study (N = 33) we used two groups of visually minimal expressive stimuli: dynamic and static. The dynamic stimuli consisted of an animated circle moving

'Proactive' use of cue-context congruence for building reinforcement learning's reward function.

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Zsuga, Judit; Biro, Klara; Tajti, Gabor; Szilasi, Magdolna Emma; Papp, Csaba; Juhasz, Bela; Gesztelyi, Rudolf

2016-10-28

Reinforcement learning is a fundamental form of learning that may be formalized using the Bellman equation. Accordingly an agent determines the state value as the sum of immediate reward and of the discounted value of future states. Thus the value of state is determined by agent related attributes (action set, policy, discount factor) and the agent's knowledge of the environment embodied by the reward function and hidden environmental factors given by the transition probability. The central objective of reinforcement learning is to solve these two functions outside the agent's control either using, or not using a model. In the present paper, using the proactive model of reinforcement learning we offer insight on how the brain creates simplified representations of the environment, and how these representations are organized to support the identification of relevant stimuli and action. Furthermore, we identify neurobiological correlates of our model by suggesting that the reward and policy functions, attributes of the Bellman equitation, are built by the orbitofrontal cortex (OFC) and the anterior cingulate cortex (ACC), respectively. Based on this we propose that the OFC assesses cue-context congruence to activate the most context frame. Furthermore given the bidirectional neuroanatomical link between the OFC and model-free structures, we suggest that model-based input is incorporated into the reward prediction error (RPE) signal, and conversely RPE signal may be used to update the reward-related information of context frames and the policy underlying action selection in the OFC and ACC, respectively. Furthermore clinical implications for cognitive behavioral interventions are discussed.

Use of Sine Shaped High-Frequency Rhythmic Visual Stimuli Patterns for SSVEP Response Analysis and Fatigue Rate Evaluation in Normal Subjects

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Ahmadreza Keihani

2018-05-01

Full Text Available Background: Recent EEG-SSVEP signal based BCI studies have used high frequency square pulse visual stimuli to reduce subjective fatigue. However, the effect of total harmonic distortion (THD has not been considered. Compared to CRT and LCD monitors, LED screen displays high-frequency wave with better refresh rate. In this study, we present high frequency sine wave simple and rhythmic patterns with low THD rate by LED to analyze SSVEP responses and evaluate subjective fatigue in normal subjects.Materials and Methods: We used patterns of 3-sequence high-frequency sine waves (25, 30, and 35 Hz to design our visual stimuli. Nine stimuli patterns, 3 simple (repetition of each of above 3 frequencies e.g., P25-25-25 and 6 rhythmic (all of the frequencies in 6 different sequences e.g., P25-30-35 were chosen. A hardware setup with low THD rate (<0.1% was designed to present these patterns on LED. Twenty two normal subjects (aged 23–30 (25 ± 2.1 yrs were enrolled. Visual analog scale (VAS was used for subjective fatigue evaluation after presentation of each stimulus pattern. PSD, CCA, and LASSO methods were employed to analyze SSVEP responses. The data including SSVEP features and fatigue rate for different visual stimuli patterns were statistically evaluated.Results: All 9 visual stimuli patterns elicited SSVEP responses. Overall, obtained accuracy rates were 88.35% for PSD and > 90% for CCA and LASSO (for TWs > 1 s. High frequency rhythmic patterns group with low THD rate showed higher accuracy rate (99.24% than simple patterns group (98.48%. Repeated measure ANOVA showed significant difference between rhythmic pattern features (P < 0.0005. Overall, there was no significant difference between the VAS of rhythmic [3.85 ± 2.13] compared to the simple patterns group [3.96 ± 2.21], (P = 0.63. Rhythmic group had lower within group VAS variation (min = P25-30-35 [2.90 ± 2.45], max = P35-25-30 [4.81 ± 2.65] as well as least individual pattern VAS (P25

Application and Evaluation of an Expert Judgment Elicitation Procedure for Correlations.

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Zondervan-Zwijnenburg, Mariëlle; van de Schoot-Hubeek, Wenneke; Lek, Kimberley; Hoijtink, Herbert; van de Schoot, Rens

2017-01-01

The purpose of the current study was to apply and evaluate a procedure to elicit expert judgments about correlations, and to update this information with empirical data. The result is a face-to-face group elicitation procedure with as its central element a trial roulette question that elicits experts' judgments expressed as distributions. During the elicitation procedure, a concordance probability question was used to provide feedback to the experts on their judgments. We evaluated the elicitation procedure in terms of validity and reliability by means of an application with a small sample of experts. Validity means that the elicited distributions accurately represent the experts' judgments. Reliability concerns the consistency of the elicited judgments over time. Four behavioral scientists provided their judgments with respect to the correlation between cognitive potential and academic performance for two separate populations enrolled at a specific school in the Netherlands that provides special education to youth with severe behavioral problems: youth with autism spectrum disorder (ASD), and youth with diagnoses other than ASD. Measures of face-validity, feasibility, convergent validity, coherence, and intra-rater reliability showed promising results. Furthermore, the current study illustrates the use of the elicitation procedure and elicited distributions in a social science application. The elicited distributions were used as a prior for the correlation, and updated with data for both populations collected at the school of interest. The current study shows that the newly developed elicitation procedure combining the trial roulette method with the elicitation of correlations is a promising tool, and that the results of the procedure are useful as prior information in a Bayesian analysis.

Effects of Auditory Stimuli on Visual Velocity Perception

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Michiaki Shibata

2011-10-01

Full Text Available We investigated the effects of auditory stimuli on the perceived velocity of a moving visual stimulus. Previous studies have reported that the duration of visual events is perceived as being longer for events filled with auditory stimuli than for events not filled with auditory stimuli, ie, the so-called “filled-duration illusion.” In this study, we have shown that auditory stimuli also affect the perceived velocity of a moving visual stimulus. In Experiment 1, a moving comparison stimulus (4.2∼5.8 deg/s was presented together with filled (or unfilled white-noise bursts or with no sound. The standard stimulus was a moving visual stimulus (5 deg/s presented before or after the comparison stimulus. The participants had to judge which stimulus was moving faster. The results showed that the perceived velocity in the auditory-filled condition was lower than that in the auditory-unfilled and no-sound conditions. In Experiment 2, we investigated the effects of auditory stimuli on velocity adaptation. The results showed that the effects of velocity adaptation in the auditory-filled condition were weaker than those in the no-sound condition. These results indicate that auditory stimuli tend to decrease the perceived velocity of a moving visual stimulus.

CCSI Risk Estimation: An Application of Expert Elicitation

Energy Technology Data Exchange (ETDEWEB)

Engel, David W.; Dalton, Angela C.

2012-10-01

The Carbon Capture Simulation Initiative (CCSI) is a multi-laboratory simulation-driven effort to develop carbon capture technologies with the goal of accelerating commercialization and adoption in the near future. One of the key CCSI technical challenges is representing and quantifying the inherent uncertainty and risks associated with developing, testing, and deploying the technology in simulated and real operational settings. To address this challenge, the CCSI Element 7 team developed a holistic risk analysis and decision-making framework. The purpose of this report is to document the CCSI Element 7 structured systematic expert elicitation to identify additional risk factors. We review the significance of and established approaches to expert elicitation, describe the CCSI risk elicitation plan and implementation strategies, and conclude by discussing the next steps and highlighting the contribution of risk elicitation toward the achievement of the overarching CCSI objectives.

Management of Reinforcement Corrosion

DEFF Research Database (Denmark)

Küter, André; Geiker, Mette Rica; Møller, Per

Reinforcement corrosion is the most important cause for deterioration of reinforced concrete structures, both with regard to costs and consequences. Thermodynamically consistent descriptions of corrosion mechanisms are expected to allow the development of innovative concepts for the management...... of reinforcement corrosion....

Visual and auditory stimuli associated with swallowing. An fMRI study

International Nuclear Information System (INIS)

Kawai, Takeshi; Watanabe, Yutaka; Tonogi, Morio; Yamane, Gen-yuki; Abe, Shinichi; Yamada, Yoshiaki; Callan, Akiko

2009-01-01

We focused on brain areas activated by audiovisual stimuli related to swallowing motions. In this study, three kinds of stimuli related to human swallowing movement (auditory stimuli alone, visual stimuli alone, or audiovisual stimuli) were presented to the subjects, and activated brain areas were measured using functional MRI (fMRI) and analyzed. When auditory stimuli alone were presented, the supplementary motor area was activated. When visual stimuli alone were presented, the premotor and primary motor areas of the left and right hemispheres and prefrontal area of the left hemisphere were activated. When audiovisual stimuli were presented, the prefrontal and premotor areas of the left and right hemispheres were activated. Activation of Broca's area, which would have been characteristic of mirror neuron system activation on presentation of motion images, was not observed; however, activation of brain areas related to swallowing motion programming and performance was verified for auditory, visual and audiovisual stimuli related to swallowing motion. These results suggest that audiovisual stimuli related to swallowing motion could be applied to the treatment of patients with dysphagia. (author)

Oral Conditioned Cues Can Enhance or Inhibit Ethanol (EtOH)-Seeking and EtOH-Relapse Drinking by Alcohol-Preferring (P) Rats.

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Knight, Christopher P; Hauser, Sheketha R; Deehan, Gerald A; Toalston, Jamie E; McBride, William J; Rodd, Zachary A

2016-04-01

Conditioned cues can elicit drug-seeking in both humans and rodents. The majority of preclinical research has employed excitatory conditioned cues (stimuli present throughout the availability of a reinforcer), but oral consumption of alcohol is similar to a conditional stimuli (presence of stimuli is paired with the delivery of the reinforcer) approach. The current experiments attempted to determine the effects of conditional stimuli (both excitatory and inhibitory) on the expression of context-induced ethanol (EtOH)-seeking. Alcohol-preferring (P) rats self-administered EtOH and water in standard 2-lever operant chambers. A flavor was added to the EtOH solution (CS+) during the EtOH self-administration sessions. After 10 weeks, rats underwent extinction training (7 sessions), followed by a 2-week home cage period. Another flavor was present during extinction (CS-). Rats were exposed to a third flavor in a non-drug-paired environment (CS(0)). EtOH-seeking was assessed in the presence of no cue, CS+, CS-, or CS(0) in the dipper previously associated with EtOH self-administration (no EtOH available). Rats were maintained a week in their home cage before being returned to the operant chambers with access to EtOH (flavored with no cue, CS+, CS-, or CS(0)). The results indicated that the presence of the CS+ enhanced EtOH-seeking, while the presence of the CS- suppressed EtOH-seeking. Similarly, adding the CS- flavor to 15% EtOH reduced responding for EtOH while the CS+ enhanced responding for EtOH during relapse testing. Overall, the data indicate that conditional stimuli are effective at altering both EtOH-seeking behavior and EtOH-relapse drinking. Copyright © 2016 by the Research Society on Alcoholism.

Perceptual Sensitivity and Response to Strong Stimuli Are Related

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Anna C. Bolders

2017-09-01

Full Text Available To shed new light on the long-standing debate about the (independence of sensitivity to weak stimuli and overreactivity to strong stimuli, we examined the relation between these tendencies within the neurobehavioral framework of the Predictive and Reactive Control Systems (PARCS theory (Tops et al., 2010, 2014. Whereas previous studies only considered overreactivity in terms of the individual tendency to experience unpleasant affect (punishment reactivity resulting from strong sensory stimulation, we also took the individual tendency to experience pleasant affect (reward reactivity resulting from strong sensory stimulation into account. According to PARCS theory, these temperamental tendencies overlap in terms of high reactivity toward stimulation, but oppose each other in terms of the response orientation (approach or avoid. PARCS theory predicts that both types of reactivity to strong stimuli relate to sensitivity to weak stimuli, but that these relationships are suppressed due to the opposing relationship between reward and punishment reactivity. We measured punishment and reward reactivity to strong stimuli and sensitivity to weak stimuli using scales from the Adult Temperament Questionnaire (Evans and Rothbart, 2007. Sensitivity was also measured more objectively using the masked auditory threshold. We found that sensitivity to weak stimuli (both self-reported and objectively assessed was positively associated with self-reported punishment and reward reactivity to strong stimuli, but only when these reactivity measures were controlled for each other, implicating a mutual suppression effect. These results are in line with PARCS theory and suggest that sensitivity to weak stimuli and overreactivity are dependent, but this dependency is likely to be obscured if punishment and reward reactivity are not both taken into account.

Stimuli-Adaptable Materials

DEFF Research Database (Denmark)

Frankær, Sarah Maria Grundahl

The work presented in this Thesis deals with the development of a stimuli-adaptable polymer material based on the UV-induced dimerisation of cinnamic acid and its derivatives. It is in the nature of an adhesive to adhere very well to its substrate and therefore problems can arise upon removal...

Perception of chemesthetic stimuli in groups who differ by food involvement and culinary experience.

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Byrnes, Nadia; Loss, Christopher R; Hayes, John E

2015-12-01

In the English language, there is generally a limited lexicon when referring to the sensations elicited by chemesthetic stimuli like capsaicin, allyl isothiocyanate, and eugenol, the orally irritating compounds found in chiles, wasabi, and cloves, respectively. Elsewhere, experts and novices have been shown to use language differently, with experts using more precise language. Here, we compare perceptual maps and word usage across three cohorts: experts with formal culinary education, naïve individuals with high Food Involvement Scale (FIS) scores, and naïve individuals with low FIS scores. We hypothesized that increased experience with foods, whether through informal experiential learning or formal culinary education, would have a significant influence on the perceptual maps generated from a sorting task conducted with chemesthetic stimuli, as well as on language use in a descriptive follow-up task to this sorting task. The low- and highFIS non-expert cohorts generated significantly similar maps, though in other respects the highFIS cohort was an intermediate between the lowFIS and expert cohorts. The highFIS and expert cohorts generated more attributes but used language more idiosyncratically than the lowFIS group. Overall, the results from the expert group with formal culinary education differed from the two naïve cohorts both in the perceptual map generated using MDS as well as the mean number of attributes generated. Present data suggest that both formal education and informal experiential learning result in lexical development, but the level and type of learning can have a significant influence on language use and the approach to a sorting task.

Effects of partial reinforcement and time between reinforced trials on terminal response rate in pigeon autoshaping.

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Gottlieb, Daniel A

2006-03-01

Partial reinforcement often leads to asymptotically higher rates of responding and number of trials with a response than does continuous reinforcement in pigeon autoshaping. However, comparisons typically involve a partial reinforcement schedule that differs from the continuous reinforcement schedule in both time between reinforced trials and probability of reinforcement. Two experiments examined the relative contributions of these two manipulations to asymptotic response rate. Results suggest that the greater responding previously seen with partial reinforcement is primarily due to differential probability of reinforcement and not differential time between reinforced trials. Further, once established, differences in responding are resistant to a change in stimulus and contingency. Secondary response theories of autoshaped responding (theories that posit additional response-augmenting or response-attenuating mechanisms specific to partial or continuous reinforcement) cannot fully accommodate the current body of data. It is suggested that researchers who study pigeon autoshaping train animals on a common task prior to training them under different conditions.

Specific Inflammatory Stimuli Lead to Distinct Platelet Responses in Mice and Humans.

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Lea M Beaulieu

Full Text Available Diverse and multi-factorial processes contribute to the progression of cardiovascular disease. These processes affect cells involved in the development of this disease in varying ways, ultimately leading to atherothrombosis. The goal of our study was to compare the differential effects of specific stimuli--two bacterial infections and a Western diet--on platelet responses in ApoE-/- mice, specifically examining inflammatory function and gene expression. Results from murine studies were verified using platelets from participants of the Framingham Heart Study (FHS; n = 1819 participants.Blood and spleen samples were collected at weeks 1 and 9 from ApoE-/- mice infected with Porphyromonas gingivalis or Chlamydia pneumoniae and from mice fed a Western diet for 9 weeks. Transcripts based on data from a Western diet in ApoE-/- mice were measured in platelet samples from FHS using high throughput qRT-PCR.At week 1, both bacterial infections increased circulating platelet-neutrophil aggregates. At week 9, these cells individually localized to the spleen, while Western diet resulted in increased platelet-neutrophil aggregates in the spleen only. Microarray analysis of platelet RNA from infected or Western diet-fed mice at week 1 and 9 showed differential profiles. Genes, such as Serpina1a, Ttr, Fgg, Rpl21, and Alb, were uniquely affected by infection and diet. Results were reinforced in platelets obtained from participants of the FHS.Using both human studies and animal models, results demonstrate that variable sources of inflammatory stimuli have the ability to influence the platelet phenotype in distinct ways, indicative of the diverse function of platelets in thrombosis, hemostasis, and immunity.

Influence of transverse reinforcement on perforation resistance of reinforced concrete slabs under hard missile impact

International Nuclear Information System (INIS)

Orbovic, Nebojsa; Sagals, Genadijs; Blahoianu, Andrei

2015-01-01

This paper describes the work conducted by the Canadian Nuclear Safety Commission (CNSC) related to the influence of transverse reinforcement on perforation capacity of reinforced concrete (RC) slabs under “hard” missile impact (impact with negligible missile deformations). The paper presents the results of three tests on reinforced concrete slabs conducted at VTT Technical Research Centre (Finland), along with the numerical simulations as well as a discussion of the current code provisions related to impactive loading. Transverse reinforcement is widely used for improving the shear and punching strength of concrete structures. However, the effect of this reinforcement on the perforation resistance under localized missile impact is still unclear. The goal of this paper is to fill the gap in the current literature related to this topic. Based on similar tests designed by the authors with missile velocity below perforation velocity, it was expected that transverse reinforcement would improve the perforation resistance. Three slabs were tested under almost identical conditions with the only difference being the transverse reinforcement. One slab was designed without transverse reinforcement, the second one with the transverse reinforcement in form of conventional stirrups with hooks and the third one with the transverse reinforcement in form of T-headed bars. Although the transverse reinforcement reduced the overall damage of the slabs (the rear face scabbing), the conclusion from the tests is that the transverse reinforcement does not have important influence on perforation capacity of concrete slabs under rigid missile impact. The slab with T-headed bars presented a slight improvement compared to the baseline specimen without transverse reinforcement. The slab with conventional stirrups presented slightly lower perforation capacity (higher residual missile velocity) than the slab without transverse reinforcement. In conclusion, the performed tests show slightly

External-stimuli responsive systems for cancer theranostic

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Jianhui Yao

2016-10-01

Full Text Available The upsurge of novel nanomaterials and nanotechnologies has inspired the researchers who are striving for designing safer and more efficient drug delivery systems for cancer therapy. Stimuli responsive nanomaterial offered an alternative to design controllable drug delivery system on account of its spatiotemporally controllable properties. Additionally, external stimuli (light, magnetic field and ultrasound could develop into theranostic applications for personalized medicine use because of their unique characteristics. In this review, we give a brief overview about the significant progresses and challenges of certain external-stimuli responsive systems that have been extensively investigated in drug delivery and theranostics within the last few years.

Attentional bias for positive emotional stimuli: A meta-analytic investigation.

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Pool, Eva; Brosch, Tobias; Delplanque, Sylvain; Sander, David

2016-01-01

Despite an initial focus on negative threatening stimuli, researchers have more recently expanded the investigation of attentional biases toward positive rewarding stimuli. The present meta-analysis systematically compared attentional bias for positive compared with neutral visual stimuli across 243 studies (N = 9,120 healthy participants) that used different types of attentional paradigms and positive stimuli. Factors were tested that, as postulated by several attentional models derived from theories of emotion, might modulate this bias. Overall, results showed a significant, albeit modest (Hedges' g = .258), attentional bias for positive as compared with neutral stimuli. Moderator analyses revealed that the magnitude of this attentional bias varied as a function of arousal and that this bias was significantly larger when the emotional stimulus was relevant to specific concerns (e.g., hunger) of the participants compared with other positive stimuli that were less relevant to the participants' concerns. Moreover, the moderator analyses showed that attentional bias for positive stimuli was larger in paradigms that measure early, rather than late, attentional processing, suggesting that attentional bias for positive stimuli occurs rapidly and involuntarily. Implications for theories of emotion and attention are discussed. (c) 2015 APA, all rights reserved).

Expert elicitation and the problem of detecting undeclared activities

International Nuclear Information System (INIS)

Pilat, Joseph F.; Sylvester, Kori Budlong; Stanbro, William D.

2002-01-01

Measures applicable to the detection of undeclared activities are not well established, and their effectiveness is uncertain. To detect clandestine paths, the IAEA is still developing processes and procedures. As the Agency gains experience with new measures and with integrated safeguards, dealing with such problems may become more experience-based and perhaps more closely parallel the process with current safeguards where detection probabilities for the measures to be utilized on declared paths are well characterized. Whether or not this point will be reached for undeclared and mixed paths, the only tool that appears suitable at present for the purpose of generating a reasonable detection probability that can over time be tested against reality and, if necessary, adjusted is formal expert judgment, or expert elicitation. Formal expert elicitation is a structured process that makes use of people knowledgeable in certain areas to make assessments. To provide a 'proof of principle' of this methodology for presentation to the Agency, experts in nuclear technology, nonproliferation, safeguards and open source information, as well as in formal expert elicitation processes, engaged in three illustrative expert elicitations on assessing information analysis as a means to detect undeclared activities. These elicitations were successful. This paper will discuss the process of and issues raised by the elicitations.

Eliciting and communicating expert judgments: Methodology and application to nuclear safety

International Nuclear Information System (INIS)

Winterfeldt, D. von

1989-01-01

The most ambitious and certainly the most extensive formal expert judgment process was the elicitation of numerous events and uncertain quantities for safety issues in five nuclear power plants in the U.S. The general methodology for formal expert elicitations are described. An overview of the expert elicitation process of NUREG 1150 is provided and the elicitation of probabilities for the interfacing systems loss of coolant accident LOCA (ISL) in PWRs is given as an example of this elicitation process. Some lessons learned from this study are presented. (DG)

Finite element modelling of concrete beams reinforced with hybrid fiber reinforced bars

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Smring, Santa binti; Salleh, Norhafizah; Hamid, NoorAzlina Abdul; Majid, Masni A.

2017-11-01

Concrete is a heterogeneous composite material made up of cement, sand, coarse aggregate and water mixed in a desired proportion to obtain the required strength. Plain concrete does not with stand tension as compared to compression. In order to compensate this drawback steel reinforcement are provided in concrete. Now a day, for improving the properties of concrete and also to take up tension combination of steel and glass fibre-reinforced polymer (GFRP) bars promises favourable strength, serviceability, and durability. To verify its promise and support design concrete structures with hybrid type of reinforcement, this study have investigated the load-deflection behaviour of concrete beams reinforced with hybrid GFRP and steel bars by using ATENA software. Fourteen beams, including six control beams reinforced with only steel or only GFRP bars, were analysed. The ratio and the ordinate of GFRP to steel were the main parameters investigated. The behaviour of these beams was investigated via the load-deflection characteristics, cracking behaviour and mode of failure. Hybrid GFRP-Steel reinforced concrete beam showed the improvement in both ultimate capacity and deflection concomitant to the steel reinforced concrete beam. On the other hand, finite element (FE) modelling which is ATENA were validated with previous experiment and promising the good result to be used for further analyses and development in the field of present study.

Preclinical assessment of the abuse potential of the orexin receptor antagonist, suvorexant.

Science.gov (United States)

Born, Stephanie; Gauvin, David V; Mukherjee, Suman; Briscoe, Richard

2017-06-01

Suvorexant (Belsomra ® ) is a dual orexin receptor antagonist approved for the treatment of insomnia. Because of its pharmacology within the central nervous system, intended therapeutic indication, and first-in-class status, an assessment of suvorexant abuse liability potential was required prior to marketing approval. The nonclinical abuse liability potential studies for suvorexant included: 1) rat drug-dependence model to assess physical dependence following abrupt cessation; 2) rat drug-discrimination model to examine the potential similarity of the interoceptive or subjective effects of suvorexant to those elicited by zolpidem and morphine; 3) self-administration model to assess the relative reinforcing efficacy of suvorexant in rhesus monkeys conditioned to self-administer methohexital. No significant signs of spontaneous drug withdrawal or 'discontinuation syndrome' were observed in rats following abrupt discontinuation of suvorexant. Suvorexant did not elicit complete cross-generalization to either a zolpidem or morphine training/reference stimuli in rats, and suvorexant was devoid of behavioral evidence of positive reinforcing efficacy in monkeys. These nonclinical findings suggested that suvorexant will have low abuse potential in humans. In the final regulatory risk assessment, suvorexant was placed into Schedule IV, likely due to its first-in-class status, its sedative properties, and the outcome of the clinical abuse potential assessment. Copyright © 2017 Elsevier Inc. All rights reserved.

Cue-Elicited Increases in Incentive Salience for Marijuana: Craving, Demand, and Attentional Bias

Science.gov (United States)

Metrik, Jane; Aston, Elizabeth R.; Kahler, Christopher W.; Rohsenow, Damaris J.; McGeary, John E.; Knopik, Valerie S.; MacKillop, James

2016-01-01

Background Incentive salience is a multidimensional construct that includes craving, drug value relative to other reinforcers, and implicit motivation such as attentional bias to drug cues. Laboratory cue reactivity (CR) paradigms have been used to evaluate marijuana incentive salience with measures of craving, but not with behavioral economic measures of marijuana demand or implicit attentional processing tasks. Methods This within-subjects study used a new CR paradigm to examine multiple dimensions of marijuana’s incentive salience and to compare CR-induced increases in craving and demand. Frequent marijuana users (N=93, 34% female) underwent exposure to neutral cues then to lit marijuana cigarettes. Craving, marijuana demand via a marijuana purchase task, and heart rate were assessed after each cue set. A modified Stroop task with cannabis and control words was completed after the marijuana cues as a measure of attentional bias. Results Relative to neutral cues, marijuana cues significantly increased subjective craving and demand indices of intensity (i.e., drug consumed at $0) and Omax (i.e., peak drug expenditure). Elasticity significantly decreased following marijuana cues, reflecting sustained purchase despite price increases. Craving was correlated with demand indices (r’s: 0.23–0.30). Marijuana users displayed significant attentional bias for cannabis-related words after marijuana cues. Cue-elicited increases in intensity were associated with greater attentional bias for marijuana words. Conclusions Greater incentive salience indexed by subjective, behavioral economic, and implicit measures was observed after marijuana versus neutral cues, supporting multidimensional assessment. The study highlights the utility of a behavioral economic approach in detecting cue-elicited changes in marijuana incentive salience. PMID:27515723

Emotional attention for erotic stimuli: Cognitive and brain mechanisms.

Science.gov (United States)

Sennwald, Vanessa; Pool, Eva; Brosch, Tobias; Delplanque, Sylvain; Bianchi-Demicheli, Francesco; Sander, David

2016-06-01

It has long been posited that among emotional stimuli, only negative threatening information modulates early shifts of attention. However, in the last few decades there has been an increase in research showing that attention is also involuntarily oriented toward positive rewarding stimuli such as babies, food, and erotic information. Because reproduction-related stimuli have some of the largest effects among positive stimuli on emotional attention, the present work reviews recent literature and proposes that the cognitive and cerebral mechanisms underlying the involuntarily attentional orientation toward threat-related information are also sensitive to erotic information. More specifically, the recent research suggests that both types of information involuntarily orient attention due to their concern relevance and that the amygdala plays an important role in detecting concern-relevant stimuli, thereby enhancing perceptual processing and influencing emotional attentional processes. © 2015 Wiley Periodicals, Inc.

Investigation of rule control by controlling the effetcts of reinforcement history on human behavior / Investigação do controle por regras e do controle por histórias de reforço sobre o comportamento humano

Directory of Open Access Journals (Sweden)

Luiz Carlos de Albuquerque

2004-01-01

Full Text Available This study investigated the role of experimental history and of relative density of reinforcement on rule following behavior. Sixteen undergraduate students participated. Under a matching-to-sample procedure, with 3 comparison stimuli, the participants were asked to point the comparisons in sequence, according to their dimension, Color, Thickness or Form, in common to the sample. At the beginning of Phases 1, 2, 3 and 4, participants were exposed, respectively, to minimal instructions, a discrepant rule (specifying a non reinforced sequence, a corresponding rule (specifying a TFC sequence and a repeated discrepant rule. Only the CTF sequence was reinforced in all phases. In Phase 3, two sequences, TFC and CTF, were concurrently reinforced (Concurrent FR 2 FR6 and FR2 FR6. Control by rules and by reinforcement history were both observed, under specific conditions. These findings have implications for drawing a distinction between behaviors controlled by rules and those shaped by contingencies.

VEP Responses to Op-Art Stimuli.

Directory of Open Access Journals (Sweden)

Louise O'Hare

Full Text Available Several types of striped patterns have been reported to cause adverse sensations described as visual discomfort. Previous research using op-art-based stimuli has demonstrated that spurious eye movement signals can cause the experience of illusory motion, or shimmering effects, which might be perceived as uncomfortable. Whilst the shimmering effects are one cause of discomfort, another possible contributor to discomfort is excessive neural responses: As striped patterns do not have the statistical redundancy typical of natural images, they are perhaps unable to be encoded efficiently. If this is the case, then this should be seen in the amplitude of the EEG response. This study found that stimuli that were judged to be most comfortable were also those with the lowest EEG amplitude. This provides some support for the idea that excessive neural responses might also contribute to discomfort judgements in normal populations, in stimuli controlled for perceived contrast.

VEP Responses to Op-Art Stimuli.

Science.gov (United States)

O'Hare, Louise; Clarke, Alasdair D F; Pollux, Petra M J

2015-01-01

Several types of striped patterns have been reported to cause adverse sensations described as visual discomfort. Previous research using op-art-based stimuli has demonstrated that spurious eye movement signals can cause the experience of illusory motion, or shimmering effects, which might be perceived as uncomfortable. Whilst the shimmering effects are one cause of discomfort, another possible contributor to discomfort is excessive neural responses: As striped patterns do not have the statistical redundancy typical of natural images, they are perhaps unable to be encoded efficiently. If this is the case, then this should be seen in the amplitude of the EEG response. This study found that stimuli that were judged to be most comfortable were also those with the lowest EEG amplitude. This provides some support for the idea that excessive neural responses might also contribute to discomfort judgements in normal populations, in stimuli controlled for perceived contrast.

Gender differences in identifying emotions from auditory and visual stimuli.

Science.gov (United States)

Waaramaa, Teija

2017-12-01

The present study focused on gender differences in emotion identification from auditory and visual stimuli produced by two male and two female actors. Differences in emotion identification from nonsense samples, language samples and prolonged vowels were investigated. It was also studied whether auditory stimuli can convey the emotional content of speech without visual stimuli, and whether visual stimuli can convey the emotional content of speech without auditory stimuli. The aim was to get a better knowledge of vocal attributes and a more holistic understanding of the nonverbal communication of emotion. Females tended to be more accurate in emotion identification than males. Voice quality parameters played a role in emotion identification in both genders. The emotional content of the samples was best conveyed by nonsense sentences, better than by prolonged vowels or shared native language of the speakers and participants. Thus, vocal non-verbal communication tends to affect the interpretation of emotion even in the absence of language. The emotional stimuli were better recognized from visual stimuli than auditory stimuli by both genders. Visual information about speech may not be connected to the language; instead, it may be based on the human ability to understand the kinetic movements in speech production more readily than the characteristics of the acoustic cues.

Stimuli-responsive nanomaterials for therapeutic protein delivery.

Science.gov (United States)

Lu, Yue; Sun, Wujin; Gu, Zhen

2014-11-28

Protein therapeutics have emerged as a significant role in treatment of a broad spectrum of diseases, including cancer, metabolic disorders and autoimmune diseases. The efficacy of protein therapeutics, however, is limited by their instability, immunogenicity and short half-life. In order to overcome these barriers, tremendous efforts have recently been made in developing controlled protein delivery systems. Stimuli-triggered release is an appealing and promising approach for protein delivery and has made protein delivery with both spatiotemporal- and dosage-controlled manners possible. This review surveys recent advances in controlled protein delivery of proteins or peptides using stimuli-responsive nanomaterials. Strategies utilizing both physiological and external stimuli are introduced and discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

Methods for producing reinforced carbon nanotubes

Science.gov (United States)

Ren, Zhifen [Newton, MA; Wen, Jian Guo [Newton, MA; Lao, Jing Y [Chestnut Hill, MA; Li, Wenzhi [Brookline, MA

2008-10-28

Methods for producing reinforced carbon nanotubes having a plurality of microparticulate carbide or oxide materials formed substantially on the surface of such reinforced carbon nanotubes composite materials are disclosed. In particular, the present invention provides reinforced carbon nanotubes (CNTs) having a plurality of boron carbide nanolumps formed substantially on a surface of the reinforced CNTs that provide a reinforcing effect on CNTs, enabling their use as effective reinforcing fillers for matrix materials to give high-strength composites. The present invention also provides methods for producing such carbide reinforced CNTs.

Time course of brain activation elicited by basic emotions.

Science.gov (United States)

Hot, Pascal; Sequeira, Henrique

2013-11-13

Whereas facial emotion recognition protocols have shown that each discrete emotion has a specific time course of brain activation, there is no electrophysiological evidence to support these findings for emotional induction by complex pictures. Our objective was to specify the differences between the time courses of brain activation elicited by feelings of happiness and, with unpleasant pictures, by feelings of disgust and sadness. We compared event-related potentials (ERPs) elicited by the watching of high-arousing pictures from the International Affective Picture System, selected to induce specific emotions. In addition to a classical arousal effect on late positive components, we found specific ERP patterns for each emotion in early temporal windows (emotion to be associated with different brain processing after 140 ms, whereas happiness and sadness differed in ERPs elicited at the frontal and central sites after 160 ms. Our findings highlight the limits of the classical averaging of ERPs elicited by different emotions inside the same valence and suggest that each emotion could elicit a specific temporal pattern of brain activation, similar to those observed with emotional face recognition.

Stimuli-Responsive Materials for Controlled Release Applications

KAUST Repository

Li, Song

2015-04-01

The controlled release of therapeutics has been one of the major challenges for scientists and engineers during the past three decades. To address this outstanding problem, the design and fabrication of stimuli-responsive materials are pursued to guarantee the controlled release of cargo at a specific time and with an accurate amount. Upon applying different stimuli such as light, magnetic field, heat, pH change, enzymes or redox, functional materials change their physicochemical properties through physical transformation or chemical reactions, allowing the release of payload agents on demand. This dissertation studied three stimuli-responsive membrane systems for controlled release from films of macro sizes to microcapsules of nano sizes. The first membrane system is a polymeric composite film which can decrease and sustain diffusion upon light irradiation. The photo-response of membranes is based on the photoreaction of cinnamic derivatives. The second one is composite membrane which can improve diffusion upon heating. The thermo-response of membranes comes from the volume phase transition ability of hydrogels. The third one is microcapsule which can release encapsulated agents upon light irradiation. The photo-response of capsules results from the photoreaction of nitrobenzyl derivatives. The study on these membrane systems reveals that stimuli-responsive release can be achieved by utilizing different functional materials on either macro or micro level. Based on the abundant family of smart materials, designing and fabricating stimuli-responsive systems shall lead to various advanced release processes on demand for biomedical applications.

Carbon Fiber Reinforced Polymer Grids for Shear and End Zone Reinforcement in Bridge Beams

Science.gov (United States)

2018-01-01

Corrosion of reinforcing steel reduces life spans of bridges throughout the United States; therefore, using non-corroding carbon fiber reinforced polymer (CFRP) reinforcement is seen as a way to increase service life. The use of CFRP as the flexural ...

Perceived duration of visual and tactile stimuli depends on perceived speed

Directory of Open Access Journals (Sweden)

Alice eTomassini

2011-09-01

Full Text Available It is known that the perceived duration of visual stimuli is strongly influenced by speed: faster moving stimuli appear to last longer. To test whether this is a general property of sensory systems we asked participants to reproduce the duration of visual and tactile gratings, and visuo-tactile gratings moving at a variable speed (3.5 – 15 cm/s for three different durations (400, 600 and 800 ms. For both modalities, the apparent duration of the stimulus increased strongly with stimulus speed, more so for tactile than for visual stimuli. In addition, visual stimuli were perceived to last approximately 200 ms longer than tactile stimuli. The apparent duration of visuo-tactile stimuli lay between the unimodal estimates, as the Bayesian account predicts, but the bimodal precision of the reproduction did not show the theoretical improvement. A cross-modal speed-matching task revealed that visual stimuli were perceived to move faster than tactile stimuli. To test whether the large difference in the perceived duration of visual and tactile stimuli resulted from the difference in their perceived speed, we repeated the time reproduction task with visual and tactile stimuli matched in apparent speed. This reduced, but did not completely eliminate the difference in apparent duration. These results show that for both vision and touch, perceived duration depends on speed, pointing to common strategies of time perception.

Audiovisual Rehabilitation in Hemianopia: A Model-Based Theoretical Investigation.

Science.gov (United States)

Magosso, Elisa; Cuppini, Cristiano; Bertini, Caterina

2017-01-01

Hemianopic patients exhibit visual detection improvement in the blind field when audiovisual stimuli are given in spatiotemporally coincidence. Beyond this "online" multisensory improvement, there is evidence of long-lasting, "offline" effects induced by audiovisual training: patients show improved visual detection and orientation after they were trained to detect and saccade toward visual targets given in spatiotemporal proximity with auditory stimuli. These effects are ascribed to the Superior Colliculus (SC), which is spared in these patients and plays a pivotal role in audiovisual integration and oculomotor behavior. Recently, we developed a neural network model of audiovisual cortico-collicular loops, including interconnected areas representing the retina, striate and extrastriate visual cortices, auditory cortex, and SC. The network simulated unilateral V1 lesion with possible spared tissue and reproduced "online" effects. Here, we extend the previous network to shed light on circuits, plastic mechanisms, and synaptic reorganization that can mediate the training effects and functionally implement visual rehabilitation. The network is enriched by the oculomotor SC-brainstem route, and Hebbian mechanisms of synaptic plasticity, and is used to test different training paradigms (audiovisual/visual stimulation in eye-movements/fixed-eyes condition) on simulated patients. Results predict different training effects and associate them to synaptic changes in specific circuits. Thanks to the SC multisensory enhancement, the audiovisual training is able to effectively strengthen the retina-SC route, which in turn can foster reinforcement of the SC-brainstem route (this occurs only in eye-movements condition) and reinforcement of the SC-extrastriate route (this occurs in presence of survived V1 tissue, regardless of eye condition). The retina-SC-brainstem circuit may mediate compensatory effects: the model assumes that reinforcement of this circuit can translate visual

Neural Processing of Emotional Musical and Nonmusical Stimuli in Depression.

Directory of Open Access Journals (Sweden)

Rebecca J Lepping

Full Text Available Anterior cingulate cortex (ACC and striatum are part of the emotional neural circuitry implicated in major depressive disorder (MDD. Music is often used for emotion regulation, and pleasurable music listening activates the dopaminergic system in the brain, including the ACC. The present study uses functional MRI (fMRI and an emotional nonmusical and musical stimuli paradigm to examine how neural processing of emotionally provocative auditory stimuli is altered within the ACC and striatum in depression.Nineteen MDD and 20 never-depressed (ND control participants listened to standardized positive and negative emotional musical and nonmusical stimuli during fMRI scanning and gave subjective ratings of valence and arousal following scanning.ND participants exhibited greater activation to positive versus negative stimuli in ventral ACC. When compared with ND participants, MDD participants showed a different pattern of activation in ACC. In the rostral part of the ACC, ND participants showed greater activation for positive information, while MDD participants showed greater activation to negative information. In dorsal ACC, the pattern of activation distinguished between the types of stimuli, with ND participants showing greater activation to music compared to nonmusical stimuli, while MDD participants showed greater activation to nonmusical stimuli, with the greatest response to negative nonmusical stimuli. No group differences were found in striatum.These results suggest that people with depression may process emotional auditory stimuli differently based on both the type of stimulation and the emotional content of that stimulation. This raises the possibility that music may be useful in retraining ACC function, potentially leading to more effective and targeted treatments.

Elicited vs. voluntary promises

NARCIS (Netherlands)

Ismayilov, H.; Potters, Jan

2017-01-01

We set up an experiment with pre-play communication to study the impact of promise elicitation by trustors from trustees on trust and trustworthiness. When given the opportunity a majority of trustors solicits a promise from the trustee. This drives up the promise making rate by trustees to almost

The neurovestibular challenges of astronauts and balance patients: some past countermeasures and two alternative approaches to elicitation, assessment and mitigation

Directory of Open Access Journals (Sweden)

Ben Lawson

2016-11-01

Full Text Available Astronauts and vestibular patients face analogous challenges to orientation function due to adaptive exogenous (weightlessness-induced or endogenous (pathology-induced alterations in the processing of acceleration stimuli. Given some neurovestibular similarities between these challenges, both affected groups may benefit from shared research approaches and adaptation measurement/improvement strategies. This paper reviews various past strategies and introduces two plausible ground-based approaches, the first of which is a method for eliciting and assessing vestibular adaptation-induced imbalance. Second, we review a strategy for mitigating imbalance associated with vestibular pathology and fostering readaptation. In discussing the first strategy (for imbalance assessment, we review a pilot study wherein imbalance was elicited (among healthy subjects via an adaptive challenge that caused a temporary/reversible disruption. The surrogate vestibular deficit was caused by a brief period of movement-induced adaptation to an altered (rotating gravitoinertial frame of reference. This elicited adaptation and caused imbalance when head movements were made after reentry into the normal (non-rotating frame of reference. We also review a strategy for fall mitigation, viz., a prototype tactile sway feedback device for aiding balance/recovery after disruptions caused by vestibular pathology. We introduce the device and review a preliminary exploration of its effectiveness in aiding clinical balance rehabilitation (discussing the implications for healthy astronauts. Both strategies reviewed in this paper represent cross-disciplinary research spin-offs: the ground-based vestibular challenge and tactile cueing display were derived from aeromedical research to benefit military aviators suffering from flight simulator-relevant aftereffects or inflight spatial disorientation, respectively. These strategies merit further evaluation using clinical and astronaut

Effect of expectation on pain assessment of lower- and higher-intensity stimuli.

Science.gov (United States)

Ružić, Valentina; Ivanec, Dragutin; Modić Stanke, Koraljka

2017-01-01

Pain modulation via expectation is a well-documented phenomenon. So far it has been shown that expectations about effectiveness of a certain treatment enhance the effectiveness of different analgesics and of drug-free pain treatments. Also, studies demonstrate that people assess same-intensity stimuli differently, depending on the experimentally induced expectations regarding the characteristics of the stimuli. Prolonged effect of expectation on pain perception and possible symmetry in conditions of lower- and higher-intensity stimuli is yet to be studied. Aim of this study is to determine the effect of expectation on the perception of pain experimentally induced by the series of higher- and lower-intensity stimuli. 192 healthy participants were assigned to four experimental groups differing by expectations regarding the intensity of painful stimuli series. Expectations of two groups were congruent with actual stimuli; one group expected and received lower-intensity stimuli and the other expected and received higher-intensity stimuli. Expectations of the remaining two groups were not congruent with actual stimuli; one group expected higher-intensity stimuli, but actually received lower-intensity stimuli while the other group expected lower-intensity stimuli, but in fact received higher-intensity ones. Each group received a series of 24 varied-intensity electrical stimuli rated by the participants on a 30° intensity scale. Expectation manipulation had statistically significant effect on pain intensity assessment. When expecting lower-intensity stimuli, the participants underestimated pain intensity and when expecting higher-intensity stimuli, they overestimated pain intensity. The effect size of expectations upon pain intensity assessment was equal for both lower- and higher-intensity stimuli. The obtained results imply that expectation manipulation can achieve the desired effect of decreasing or increasing both slight and more severe pain for a longer period of

Combining noncontingent reinforcement and differential reinforcement schedules as treatment for aberrant behavior.

OpenAIRE

Marcus, B A; Vollmer, T R

1996-01-01

Research has shown that noncontingent reinforcement (NCR) can be an effective behavior-reduction procedure when based on a functional analysis. The effects of NCR may be a result of elimination of the contingency between aberrant behavior and reinforcing consequences (extinction) or frequent and free access to reinforcers that may reduce the participant's motivation to engage in aberrant behaviors or mands. If motivation is momentarily reduced, behavior such as mands may not be sensitive to p...

Degradation of Waterfront Reinforced Concrete Structures

African Journals Online (AJOL)

Key words: Degradation, reinforced concrete, Dar es Salaam port. Abstract—One of the ... especially corrosion of the reinforcement. ... Corrosion of steel reinforcement contributes .... cracks along the line of reinforcement bars and most of the ...

Confinement of Reinforced-Concrete Columns with Non-Code Compliant Confining Reinforcement plus Supplemental Pen-Binder

Directory of Open Access Journals (Sweden)

Anang Kristianto

2012-11-01

Full Text Available One of the important requirements for earthquake resistant building related to confinement is the use of seismic hooks in the hoop or confining reinforcement of reinforced-concrete column elements. However, installation of a confining reinforcement with a 135-degree hook is not easy. Therefore, in practice, many construction workers apply a confining reinforcement with a 90-degreehook (non-code compliant. Based on research and records of recent earthquakes in Indonesia, the use of a non-code compliant confining reinforcement for concrete columns produces structures with poor seismic performance. This paper presents a study that introduces an additional element that is expected to improve the effectiveness of concrete columns confined with a non-code compliant confining reinforcement. The additional element, named a pen-binder, is used to keep the non-code compliant confining reinforcement in place. The effectiveness of this element under pure axial concentric loading was investigatedcomprehensively.The specimens tested in this study were 18 concrete columns,with a cross-section of 170 mm x 170 mm and a height of 480 mm. The main test variables were the material type of the pen-binder, the angle of the hook, and the confining reinforcement configuration.The test results indicate that adding pen-binders can effectively improve the strength and ductility of the column specimens confined with a non-code compliant confining reinforcement

Eliciting expert opinion for economic models: an applied example.

Science.gov (United States)

Leal, José; Wordsworth, Sarah; Legood, Rosa; Blair, Edward

2007-01-01

Expert opinion is considered as a legitimate source of information for decision-analytic modeling where required data are unavailable. Our objective was to develop a practical computer-based tool for eliciting expert opinion about the shape of the uncertainty distribution around individual model parameters. We first developed a prepilot survey with departmental colleagues to test a number of alternative approaches to eliciting opinions on the shape of the uncertainty distribution around individual parameters. This information was used to develop a survey instrument for an applied clinical example. This involved eliciting opinions from experts to inform a number of parameters involving Bernoulli processes in an economic model evaluating DNA testing for families with a genetic disease, hypertrophic cardiomyopathy. The experts were cardiologists, clinical geneticists, and laboratory scientists working with cardiomyopathy patient populations and DNA testing. Our initial prepilot work suggested that the more complex elicitation techniques advocated in the literature were difficult to use in practice. In contrast, our approach achieved a reasonable response rate (50%), provided logical answers, and was generally rated as easy to use by respondents. The computer software user interface permitted graphical feedback throughout the elicitation process. The distributions obtained were incorporated into the model, enabling the use of probabilistic sensitivity analysis. There is clearly a gap in the literature between theoretical elicitation techniques and tools that can be used in applied decision-analytic models. The results of this methodological study are potentially valuable for other decision analysts deriving expert opinion.

Influence of reinforcement's corrosion into hyperstatic reinforced concrete beams: a probabilistic failure scenarios analysis

Directory of Open Access Journals (Sweden)

G. P. PELLIZZER

Full Text Available AbstractThis work aims to study the mechanical effects of reinforcement's corrosion in hyperstatic reinforced concrete beams. The focus is the probabilistic determination of individual failure scenarios change as well as global failure change along time. The limit state functions assumed describe analytically bending and shear resistance of reinforced concrete rectangular cross sections as a function of steel and concrete resistance and section dimensions. It was incorporated empirical laws that penalize the steel yield stress and the reinforcement's area along time in addition to Fick's law, which models the chloride penetration into concrete pores. The reliability theory was applied based on Monte Carlo simulation method, which assesses each individual probability of failure. The probability of global structural failure was determined based in the concept of failure tree. The results of a hyperstatic reinforced concrete beam showed that reinforcements corrosion make change into the failure scenarios modes. Therefore, unimportant failure modes in design phase become important after corrosion start.

Characterization of Ferrofluid-based Stimuli-responsive Elastomers

OpenAIRE

Sandra dePedro; Xavier Munoz-Berbel; Rosalia Rodríguez-Rodríguez; Jordi Sort; Jose Antonio Plaza; Juergen Brugger; Andreu Llobera; Victor J Cadarso

2016-01-01

Stimuli-responsive materials undergo physicochemical and/or structural changes when a specific actuation is applied. They are heterogeneous composites, consisting of a non-responsive matrix where functionality is provided by the filler. Surprisingly, the synthesis of polydimethylsiloxane (PDMS)-based stimuli-responsive elastomers (SRE) has seldomly been presented. Here, we present the structural, biological, optical, magnetic, and mechanical properties of several magnetic SRE (M-SRE) obtained...

Separating discriminative and function-altering effects of verbal stimuli

OpenAIRE

Schlinger, Henry D.

1993-01-01

Ever since Skinner's first discussion of rule-governed behavior, behavior analysts have continued to define rules, either explicitly or implicitly, as verbal discriminative stimuli. Consequently, it is not difficult to find, in the literature on rule-governed behavior, references to stimulus control, antecedent control, or to rules occasioning behavior. However, some verbal stimuli have effects on behavior that are not easily described as discriminative. Such stimuli don't evoke behavior as d...

Natural stimuli improve auditory BCIs with respect to ergonomics and performance

Science.gov (United States)

Höhne, Johannes; Krenzlin, Konrad; Dähne, Sven; Tangermann, Michael

2012-08-01

Moving from well-controlled, brisk artificial stimuli to natural and less-controlled stimuli seems counter-intuitive for event-related potential (ERP) studies. As natural stimuli typically contain a richer internal structure, they might introduce higher levels of variance and jitter in the ERP responses. Both characteristics are unfavorable for a good single-trial classification of ERPs in the context of a multi-class brain-computer interface (BCI) system, where the class-discriminant information between target stimuli and non-target stimuli must be maximized. For the application in an auditory BCI system, however, the transition from simple artificial tones to natural syllables can be useful despite the variance introduced. In the presented study, healthy users (N = 9) participated in an offline auditory nine-class BCI experiment with artificial and natural stimuli. It is shown that the use of syllables as natural stimuli does not only improve the users’ ergonomic ratings; also the classification performance is increased. Moreover, natural stimuli obtain a better balance in multi-class decisions, such that the number of systematic confusions between the nine classes is reduced. Hopefully, our findings may contribute to make auditory BCI paradigms more user friendly and applicable for patients.

Finite element modeling of reinforced concrete beams with a hybrid combination of steel and aramid reinforcement

International Nuclear Information System (INIS)

Hawileh, R.A.

2015-01-01

Highlights: • Modeling of concrete beams reinforced steel and FRP bars. • Developed finite element models achieved good results. • The models are validated via comparison with experimental results. • Parametric studies are performed. - Abstract: Corrosion of steel bars has an adverse effect on the life-span of reinforced concrete (RC) members and is usually associated with crack development in RC beams. Fiber reinforced polymer (FRP) bars have been recently used to reinforce concrete members in flexure due to their high tensile strength and superior corrosion resistance properties. However, FRP materials are brittle in nature, thus RC beams reinforced with such materials would exhibit a less ductile behavior when compared to similar members reinforced with conventional steel reinforcement. Recently, researchers investigated the performance of concrete beams reinforced with a hybrid combination of steel and Aramid Fiber Reinforced Polymer (AFRP) reinforcement to maintain a reasonable level of ductility in such members. The function of the AFRP bars is to increase the load-carrying capacity, while the function of the steel bars is to ensure ductility of the flexural member upon yielding in tension. This paper presents a three-dimensional (3D) finite element (FE) model that predicted the load versus mid-span deflection response of tested RC beams conducted by other researchers with a hybrid combination of steel and AFRP bars. The developed FE models account for the constituent material nonlinearities and bond–slip behavior between the reinforcing bars and adjacent concrete surfaces. It was concluded that the developed models can accurately capture the behavior and predicts the load-carrying capacity of such RC members. In addition, a parametric study is conducted using the validated models to investigate the effect of AFRP bar size, FRP material type, bond–slip action, and concrete compressive strength on the performance of concrete beams when reinforced

Health monitoring of precast bridge deck panels reinforced with glass fiber reinforced polymer (GFRP) bars.

Science.gov (United States)

2012-03-01

The present research project investigates monitoring concrete precast panels for bridge decks that are reinforced with Glass Fiber Reinforced Polymer (GFRP) bars. Due to the lack of long term research on concrete members reinforced with GFRP bars, lo...

Pressurized transient otoacoustic emissions measured using click and chirp stimuli.

Science.gov (United States)

Keefe, Douglas H; Patrick Feeney, M; Hunter, Lisa L; Fitzpatrick, Denis F; Sanford, Chris A

2018-01-01

Transient-evoked otoacoustic emission (TEOAE) responses were measured in normal-hearing adult ears over frequencies from 0.7 to 8 kHz, and analyzed with reflectance/admittance data to measure absorbed sound power and the tympanometric peak pressure (TPP). The mean TPP was close to ambient. TEOAEs were measured in the ear canal at ambient pressure, TPP, and fixed air pressures from 150 to -200 daPa. Both click and chirp stimuli were used to elicit TEOAEs, in which the incident sound pressure level was constant across frequency. TEOAE levels were similar at ambient and TPP, and for frequencies from 0.7 to 2.8 kHz decreased with increasing positive and negative pressures. At 4-8 kHz, TEOAE levels were larger at positive pressures. This asymmetry is possibly related to changes in mechanical transmission through the ossicular chain. The mean TEOAE group delay did not change with pressure, although small changes were observed in the mean instantaneous frequency and group spread. Chirp TEOAEs measured in an adult ear with Eustachian tube dysfunction and TPP of -165 daPa were more robust at TPP than at ambient. Overall, results demonstrate the feasibility and clinical potential of measuring TEOAEs at fixed pressures in the ear canal, which provide additional information relative to TEOAEs measured at ambient pressure.

Video elicitation interviews: a qualitative research method for investigating physician-patient interactions.

Science.gov (United States)

Henry, Stephen G; Fetters, Michael D

2012-01-01

We describe the concept and method of video elicitation interviews and provide practical guidance for primary care researchers who want to use this qualitative method to investigate physician-patient interactions. During video elicitation interviews, researchers interview patients or physicians about a recent clinical interaction using a video recording of that interaction as an elicitation tool. Video elicitation is useful because it allows researchers to integrate data about the content of physician-patient interactions gained from video recordings with data about participants' associated thoughts, beliefs, and emotions gained from elicitation interviews. This method also facilitates investigation of specific events or moments during interactions. Video elicitation interviews are logistically demanding and time consuming, and they should be reserved for research questions that cannot be fully addressed using either standard interviews or video recordings in isolation. As many components of primary care fall into this category, high-quality video elicitation interviews can be an important method for understanding and improving physician-patient interactions in primary care.

Video Elicitation Interviews: A Qualitative Research Method for Investigating Physician-Patient Interactions

Science.gov (United States)

Henry, Stephen G.; Fetters, Michael D.

2012-01-01

We describe the concept and method of video elicitation interviews and provide practical guidance for primary care researchers who want to use this qualitative method to investigate physician-patient interactions. During video elicitation interviews, researchers interview patients or physicians about a recent clinical interaction using a video recording of that interaction as an elicitation tool. Video elicitation is useful because it allows researchers to integrate data about the content of physician-patient interactions gained from video recordings with data about participants’ associated thoughts, beliefs, and emotions gained from elicitation interviews. This method also facilitates investigation of specific events or moments during interactions. Video elicitation interviews are logistically demanding and time consuming, and they should be reserved for research questions that cannot be fully addressed using either standard interviews or video recordings in isolation. As many components of primary care fall into this category, high-quality video elicitation interviews can be an important method for understanding and improving physician-patient interactions in primary care. PMID:22412003

Eliciting and communicating expert judgments: methodology and application to nuclear safety

International Nuclear Information System (INIS)

Winterfeldt, D. von; Commission of the European Communities, Ispra

1989-01-01

Expert judgment has always been used informally in the analysis of complex engineering problems. Increasingly, however, the use of expert judgment has been formalized by eliciting judgments in an explicit, documented and often quantitative way. In nuclear safety studies the need for formal elicitation of expert judgments arises because of the lack of data and experiences, the need to adapt model results to the specific circumstances of a plant, and the large uncertainties surrounding the events and quantities that characterize an accident sequence. The recognition of the need for a formal elicitation of expert judgments has led to one of the most extensive expert elicitation processes to date in the context of the NUREG 1150 study. About 30 safety issues were quantified using expert judgments about probabilities of various uncertain events and quantities, ranging from the failure of a check valve in the cooling system to the pressure built up due to hydrogen production to release fractions of various radionuclides. In total, some 1000 probability distributions were elicited from some 50 experts. This paper first motivates the use of formal expert elicitation in complex engineering studies and describes the methodology of formal expert elicitation. Subsequently, it describes the overall approach of NUREG 1150 and provides an example of the elicitation of the probability of a bypass failure in a pressurized water reactor. The paper ends by discussing some lessons learned, problems encountered and by providing some recommendations

Multi-Functional Stimuli-Responsive Materials

Data.gov (United States)

National Aeronautics and Space Administration — Supramolecular polymers based on non-covalent interactions can display a wide array of stimuli-responsive attributes. They can be tailored to change shape, actuate...

Caregiver preference for reinforcement-based interventions for problem behavior maintained by positive reinforcement.

Science.gov (United States)

Gabor, Anne M; Fritz, Jennifer N; Roath, Christopher T; Rothe, Brittany R; Gourley, Denise A

2016-06-01

Social validity of behavioral interventions typically is assessed with indirect methods or by determining preferences of the individuals who receive treatment, and direct observation of caregiver preference rarely is described. In this study, preferences of 5 caregivers were determined via a concurrent-chains procedure. Caregivers were neurotypical, and children had been diagnosed with developmental disabilities and engaged in problem behavior maintained by positive reinforcement. Caregivers were taught to implement noncontingent reinforcement (NCR), differential reinforcement of alternative behavior (DRA), and differential reinforcement of other behavior (DRO), and the caregivers selected interventions to implement during sessions with the child after they had demonstrated proficiency in implementing the interventions. Three caregivers preferred DRA, 1 caregiver preferred differential reinforcement procedures, and 1 caregiver did not exhibit a preference. Direct observation of implementation in concurrent-chains procedures may allow the identification of interventions that are implemented with sufficient integrity and preferred by caregivers. © 2016 Society for the Experimental Analysis of Behavior.

Long-latency auditory evoked potentials with verbal and nonverbal stimuli.

Science.gov (United States)

Oppitz, Sheila Jacques; Didoné, Dayane Domeneghini; Silva, Débora Durigon da; Gois, Marjana; Folgearini, Jordana; Ferreira, Geise Corrêa; Garcia, Michele Vargas

2015-01-01

Long-latency auditory evoked potentials represent the cortical activity related to attention, memory, and auditory discrimination skills. Acoustic signal processing occurs differently between verbal and nonverbal stimuli, influencing the latency and amplitude patterns. To describe the latencies of the cortical potentials P1, N1, P2, N2, and P3, as well as P3 amplitude, with different speech stimuli and tone bursts, and to classify them in the presence and absence of these data. A total of 30 subjects with normal hearing were assessed, aged 18-32 years old, matched by gender. Nonverbal stimuli were used (tone burst; 1000Hz - frequent and 4000Hz - rare); and verbal (/ba/ - frequent; /ga/, /da/, and /di/ - rare). Considering the component N2 for tone burst, the lowest latency found was 217.45ms for the BA/DI stimulus; the highest latency found was 256.5ms. For the P3 component, the shortest latency with tone burst stimuli was 298.7 with BA/GA stimuli, the highest, was 340ms. For the P3 amplitude, there was no statistically significant difference among the different stimuli. For latencies of components P1, N1, P2, N2, P3, there were no statistical differences among them, regardless of the stimuli used. There was a difference in the latency of potentials N2 and P3 among the stimuli employed but no difference was observed for the P3 amplitude. Copyright © 2015 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Long-latency auditory evoked potentials with verbal and nonverbal stimuli,

Directory of Open Access Journals (Sweden)

Sheila Jacques Oppitz

2015-12-01

Full Text Available ABSTRACT INTRODUCTION: Long-latency auditory evoked potentials represent the cortical activity related to attention, memory, and auditory discrimination skills. Acoustic signal processing occurs differently between verbal and nonverbal stimuli, influencing the latency and amplitude patterns. OBJECTIVE: To describe the latencies of the cortical potentials P1, N1, P2, N2, and P3, as well as P3 amplitude, with different speech stimuli and tone bursts, and to classify them in the presence and absence of these data. METHODS: A total of 30 subjects with normal hearing were assessed, aged 18-32 years old, matched by gender. Nonverbal stimuli were used (tone burst; 1000 Hz - frequent and 4000 Hz - rare; and verbal (/ba/ - frequent; /ga/, /da/, and /di/ - rare. RESULTS: Considering the component N2 for tone burst, the lowest latency found was 217.45 ms for the BA/DI stimulus; the highest latency found was 256.5 ms. For the P3 component, the shortest latency with tone burst stimuli was 298.7 with BA/GA stimuli, the highest, was 340 ms. For the P3 amplitude, there was no statistically significant difference among the different stimuli. For latencies of components P1, N1, P2, N2, P3, there were no statistical differences among them, regardless of the stimuli used. CONCLUSION: There was a difference in the latency of potentials N2 and P3 among the stimuli employed but no difference was observed for the P3 amplitude.

Food-related attentional bias. Word versus pictorial stimuli and the importance of stimuli calorific value in the dot probe task.

Science.gov (United States)

Freijy, Tanya; Mullan, Barbara; Sharpe, Louise

2014-12-01

The primary aim of this study was to extend previous research on food-related attentional biases by examining biases towards pictorial versus word stimuli, and foods of high versus low calorific value. It was expected that participants would demonstrate greater biases to pictures over words, and to high-calorie over low-calorie foods. A secondary aim was to examine associations between BMI, dietary restraint, external eating and attentional biases. It was expected that high scores on these individual difference variables would be associated with a bias towards high-calorie stimuli. Undergraduates (N = 99) completed a dot probe task including matched word and pictorial food stimuli in a controlled setting. Questionnaires assessing eating behaviour were administered, and height and weight were measured. Contrary to predictions, there were no main effects for stimuli type (pictures vs words) or calorific value (high vs low). There was, however, a significant interaction effect suggesting a bias towards high-calorie pictures, but away from high-calorie words; and a bias towards low-calorie words, but away from low-calorie pictures. No associations between attentional bias and any of the individual difference variables were found. The presence of a stimulus type by calorific value interaction demonstrates the importance of stimuli type in the dot probe task, and may help to explain inconsistencies in prior research. Further research is needed to clarify associations between attentional bias and BMI, restraint, and external eating. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of reinforcer magnitude on responding under differential-reinforcement-of-low-rate schedules of rats and pigeons.

Science.gov (United States)

Doughty, Adam H; Richards, Jerry B

2002-07-01

Experiment I investigated the effects of reinforcer magnitude on differential-reinforcement-of-low-rate (DRL) schedule performance in three phases. In Phase 1, two groups of rats (n = 6 and 5) responded under a DRI. 72-s schedule with reinforcer magnitudes of either 30 or 300 microl of water. After acquisition, the water amounts were reversed for each rat. In Phase 2, the effects of the same reinforcer magnitudes on DRL 18-s schedule performance were examined across conditions. In Phase 3, each rat responded unider a DR1. 18-s schedule in which the water amotnts alternated between 30 and 300 microl daily. Throughout each phase of Experiment 1, the larger reinforcer magnitude resulted in higher response rates and lower reinforcement rates. The peak of the interresponse-time distributions was at a lower value tinder the larger reinforcer magnitude. In Experiment 2, 3 pigeons responded under a DRL 20-s schedule in which reinforcer magnitude (1-s or 6-s access to grain) varied iron session to session. Higher response rates and lower reinforcement rates occurred tinder the longer hopper duration. These results demonstrate that larger reinforcer magnitudes engender less efficient DRL schedule performance in both rats and pigeons, and when reinforcer magnitude was held constant between sessions or was varied daily. The present results are consistent with previous research demonstrating a decrease in efficiency as a function of increased reinforcer magnituide tinder procedures that require a period of time without a specified response. These findings also support the claim that DRI. schedule performance is not governed solely by a timing process.

Lingering representations of stimuli influence recall organization

Science.gov (United States)

Chan, Stephanie C.Y.; Applegate, Marissa C.; Morton, Neal W; Polyn, Sean M.; Norman, Kenneth A.

2017-01-01

Several prominent theories posit that information about recent experiences lingers in the brain and organizes memories for current experiences, by forming a temporal context that is linked to those memories at encoding. According to these theories, if the thoughts preceding an experience X resemble the thoughts preceding an experience Y, then X and Y should show an elevated probability of being recalled together. We tested this prediction by using multi-voxel pattern analysis (MVPA) of fMRI data to measure neural evidence for lingering processing of preceding stimuli. As predicted, memories encoded with similar lingering thoughts about the category of preceding stimuli were more likely to be recalled together. Our results demonstrate that the “fading embers” of previous stimuli help to organize recall, confirming a key prediction of computational models of episodic memory. PMID:28132858

Lingering representations of stimuli influence recall organization.

Science.gov (United States)

Chan, Stephanie C Y; Applegate, Marissa C; Morton, Neal W; Polyn, Sean M; Norman, Kenneth A

2017-03-01

Several prominent theories posit that information about recent experiences lingers in the brain and organizes memories for current experiences, by forming a temporal context that is linked to those memories at encoding. According to these theories, if the thoughts preceding an experience X resemble the thoughts preceding an experience Y, then X and Y should show an elevated probability of being recalled together. We tested this prediction by using multi-voxel pattern analysis (MVPA) of fMRI data to measure neural evidence for lingering processing of preceding stimuli. As predicted, memories encoded with similar lingering thoughts about the category of preceding stimuli were more likely to be recalled together. Our results demonstrate that the "fading embers" of previous stimuli help to organize recall, confirming a key prediction of computational models of episodic memory. Copyright © 2017 Elsevier Ltd. All rights reserved.

The mere exposure effect with scene stimuli

OpenAIRE

八木　, 善彦

2016-01-01

　The mere exposure effect refers to the phenomenon where previous exposures to stimuli increasesubsequent affective preference for those stimuli. It has been indicated that with specific stimulus-category（i.e., paintings, matrices, and photographs of scene）, repeated exposure has little or oppositeeffect on affective ratings. In this study, two experiments were conducted in order to explore theeffect of stimulus-category on the mere exposure effects. Photographs of young woman’s（Experiment1）a...

Using frequency tagging to quantify attentional deployment in a visual divided attention task

NARCIS (Netherlands)

Toffanin, Paolo; de Jong, Ritske; Johnson, Addie; Martens, Sander

Frequency tagging is an EEG method based on the quantification of the steady state visual evoked potential (SSVEP) elicited from stimuli which flicker with a distinctive frequency. Because the amplitude of the SSVEP is modulated by attention such that attended stimuli elicit higher SSVEP amplitudes

The usage of carbon fiber reinforcement polymer and glass fiber reinforcement polymer for retrofit technology building

Science.gov (United States)

Tarigan, Johannes; Meka, Randi; Nursyamsi

2018-03-01

Fiber Reinforcement Polymer has been used as a material technology since the 1970s in Europe. Fiber Reinforcement Polymer can reinforce the structure externally, and used in many types of buildings like beams, columns, and slabs. It has high tensile strength. Fiber Reinforcement Polymer also has high rigidity and strength. The profile of Fiber Reinforcement Polymer is thin and light, installation is simple to conduct. One of Fiber Reinforcement Polymer material is Carbon Fiber Reinforcement Polymer and Glass Fiber Reinforcement Polymer. These materials is tested when it is installed on concrete cylinders, to obtain the comparison of compressive strength CFRP and GFRP. The dimension of concrete is diameter of 15 cm and height of 30 cm. It is amounted to 15 and divided into three groups. The test is performed until it collapsed to obtain maximum load. The results of research using CFRP and GFRP have shown the significant enhancement in compressive strength. CFRP can increase the compressive strength of 26.89%, and GFRP of 14.89%. For the comparison of two materials, CFRP is more strengthening than GFRP regarding increasing compressive strength. The usage of CFRP and GFRP can increase the loading capacity.

Vection is modulated by the semantic meaning of stimuli and experimental instructions.

Science.gov (United States)

Ogawa, Masaki; Seno, Takeharu

2014-01-01

Vection strength is modulated by the semantic meanings of stimuli. In experiment 1--even though vection stimuli were of uniform size, color, and luminance--when they also had semantic meaning as falling objects, vection was inhibited. Specifically, stimuli perceived as feathers, petals, and leaves did not effectively induce vection. In experiment 2 we used the downward motion of identical dots to induce vection. Participants observed stimuli while holding either an umbrella or a wooden sword. Results showed that vection was inhibited when participants held the umbrella and the stimuli was perceived as rain or snow falling. The two experiments suggest that vection is modulated by the semantic meaning of stimuli.

The potential for using visual elicitation in understanding preschool ...

African Journals Online (AJOL)

We explore the use of video and photo elicitation in a research study undertaken to understand the way in which preschool teachers perceive and construct their provision of children's educational experiences. We explore the value of visually elicited interviews based on video footage and photographs captured during ...

Reinforced concrete tomography

International Nuclear Information System (INIS)

Mariscotti, M.A.J.; Morixe, M.; Tarela, P.A.; Thieberger, P.

1997-01-01

In this paper we describe the technique of reinforced concrete tomography, its historical background, recent technological developments and main applications. Gamma radiation sensitive plates are imprinted with radiation going through the concrete sample under study, and then processed to reveal the presence of reinforcement and defects in the material density. The three dimensional reconstruction, or tomography, of the reinforcement out of a single gammagraphy is an original development alternative to conventional methods. Re-bar diameters and positions may be determined with an accuracy of ± 1 mm 0.5-1 cm, respectively. The non-destructive character of this technique makes it particularly attractive in cases of inhabited buildings and diagnoses of balconies. (author) [es

Explaining choice option attractiveness by beliefs elicited by the laddering method

DEFF Research Database (Denmark)

Grunert, Klaus G.; Bech-Larsen, Tino

2005-01-01

option. The laddering method is used to elicit beliefs of all three types for a choice between conventional and organic pork. As a benchmark, beliefs were also elicited in the traditional way advocated by Ajzen and Fishbein. Using both sets of beliefs in a subsequent survey, it was shown that the beliefs...... elicited by the laddering method increase explanatory power with regard to choice option attractiveness beyond the beliefs elicited by the Ajzen and Fishbein method, and that this additional explanatory power was due to those beliefs which relate the choice option to concepts with a higher level...

Responsibilities in the Usability Requirements Elicitation Process

Directory of Open Access Journals (Sweden)

Marianella Aveledo

2008-12-01

Full Text Available Like any other software system quality attribute, usability places requirements on software components. In particular, it has been demonstrated that certain usability features have a direct impact throughout the software process. This paper details an approach that looks at how to deal with certain usability features in the early software development stages. In particular, we consider usability features as functional usability requirements using patterns that have been termed usability patterns to elicit requirements. Additionally, we clearly establish the responsibilities of all the players at the usability requirements elicitation stage.

Perceptual multistability in figure-ground segregation using motion stimuli.

Science.gov (United States)

Gori, Simone; Giora, Enrico; Pedersini, Riccardo

2008-11-01

In a series of experiments using ambiguous stimuli, we investigate the effects of displaying ordered, discrete series of images on the dynamics of figure-ground segregation. For low frame presentation speeds, the series were perceived as a sequence of discontinuous, static images, while for high speeds they were perceived as continuous. We conclude that using stimuli varying continuously along one parameter results in stronger hysteresis and reduces spontaneous switching compared to matched static stimuli with discontinuous parameter changes. The additional evidence that the size of the hysteresis effects depended on trial duration is consistent with the stochastic nature of the dynamics governing figure-ground segregation. The results showed that for continuously changing stimuli, alternative figure-ground organizations are resolved via low-level, dynamical competition. A second series of experiments confirmed these results with an ambiguous stimulus based on Petter's effect.

Generating Stimuli for Neuroscience Using PsychoPy.

Science.gov (United States)

Peirce, Jonathan W

2008-01-01

PsychoPy is a software library written in Python, using OpenGL to generate very precise visual stimuli on standard personal computers. It is designed to allow the construction of as wide a variety of neuroscience experiments as possible, with the least effort. By writing scripts in standard Python syntax users can generate an enormous variety of visual and auditory stimuli and can interact with a wide range of external hardware (enabling its use in fMRI, EEG, MEG etc.). The structure of scripts is simple and intuitive. As a result, new experiments can be written very quickly, and trying to understand a previously written script is easy, even with minimal code comments. PsychoPy can also generate movies and image sequences to be used in demos or simulated neuroscience experiments. This paper describes the range of tools and stimuli that it provides and the environment in which experiments are conducted.

Prediction of reinforcement corrosion using corrosion induced cracks width in corroded reinforced concrete beams

International Nuclear Information System (INIS)

Khan, Inamullah; François, Raoul; Castel, Arnaud

2014-01-01

This paper studies the evolution of reinforcement corrosion in comparison to corrosion crack width in a highly corroded reinforced concrete beam. Cracking and corrosion maps of the beam were drawn and steel reinforcement was recovered from the beam to observe the corrosion pattern and to measure the loss of mass of steel reinforcement. Maximum steel cross-section loss of the main reinforcement and average steel cross-section loss between stirrups were plotted against the crack width. The experimental results were compared with existing models proposed by Rodriguez et al., Vidal et al. and Zhang et al. Time prediction models for a given opening threshold are also compared to experimental results. Steel cross-section loss for stirrups was also measured and was plotted against the crack width. It was observed that steel cross-section loss in the stirrups had no relationship with the crack width of longitudinal corrosion cracks. -- Highlights: •Relationship between crack and corrosion of reinforcement was investigated. •Corrosion results of natural process and then corresponds to in-situ conditions. •Comparison with time predicting model is provided. •Prediction of load-bearing capacity from crack pattern was studied

Study of the internal confinement of concrete reinforced (in civil engineering) with woven reinforcement

Science.gov (United States)

Dalal, M.; Goumairi, O.; El Malik, A.

2017-10-01

Concrete is generally the most used material in the field of construction. Despite its extensive use in structures, it represents some drawbacks related to its properties including its low tensile strength and low ductility. To solve this problem, the use of steel reinforcement in concrete structures is possible. Another possibility is the introduction of different types of continuous fibre / staple in the concrete, such as steel fibres or synthetic fibres, to obtain ″Concretes bundles″. Many types of fibre concrete, which have been developed and for many of them, the gain provided by the fibre was rather low and no significant improvement in tensile strength was really reaching. By cons, the ductility was higher than that of ordinary concrete. The objective of this study is to examine concrete reinforcement by inserting reinforcements woven polyester. These are either woven bidirectional (2D) or three-dimensional woven (3D). So we will report the properties of each type of reinforcement and the influence of the method of weaving on the strength reinforcements and on the strength of concrete in which they are incorporated. Such influence should contribute to improving the sustainability and enhancement of reinforcement

The role of pulse shape in motor cortex transcranial magnetic stimulation using full-sine stimuli.

Directory of Open Access Journals (Sweden)

Igor Delvendahl

Full Text Available A full-sine (biphasic pulse waveform is most commonly used for repetitive transcranial magnetic stimulation (TMS, but little is known about how variations in duration or amplitude of distinct pulse segments influence the effectiveness of a single TMS pulse to elicit a corticomotor response. Using a novel TMS device, we systematically varied the configuration of full-sine pulses to assess the impact of configuration changes on resting motor threshold (RMT as measure of stimulation effectiveness with single-pulse TMS of the non-dominant motor hand area (M1. In young healthy volunteers, we (i compared monophasic, half-sine, and full-sine pulses, (ii applied two-segment pulses consisting of two identical half-sines, and (iii manipulated amplitude, duration, and current direction of the first or second full-sine pulse half-segments. RMT was significantly higher using half-sine or monophasic pulses compared with full-sine. Pulses combining two half-sines of identical polarity and duration were also characterized by higher RMT than full-sine stimuli resulting. For full-sine stimuli, decreasing the amplitude of the half-segment inducing posterior-anterior oriented current in M1 resulted in considerably higher RMT, whereas varying the amplitude of the half-segment inducing anterior-posterior current had a smaller effect. These findings provide direct experimental evidence that the pulse segment inducing a posterior-anterior directed current in M1 contributes most to corticospinal pathway excitation. Preferential excitation of neuronal target cells in the posterior-anterior segment or targeting of different neuronal structures by the two half-segments can explain this result. Thus, our findings help understanding the mechanisms of neural stimulation by full-sine TMS.

Extinction and renewal of cue-elicited reward-seeking.

Science.gov (United States)

Bezzina, Louise; Lee, Jessica C; Lovibond, Peter F; Colagiuri, Ben

2016-12-01

Reward cues can contribute to overconsumption of food and drugs and can relapse. The failure of exposure therapies to reduce overconsumption and relapse is generally attributed to the context-specificity of extinction. However, no previous study has examined whether cue-elicited reward-seeking (as opposed to cue-reactivity) is sensitive to context renewal. We tested this possibility in 160 healthy volunteers using a Pavlovian-instrumental transfer (PIT) design involving voluntary responding for a high value natural reward (chocolate). One reward cue underwent Pavlovian extinction in the same (Group AAA) or different context (Group ABA) to all other phases. This cue was compared with a second non-extinguished reward cue and an unpaired control cue. There was a significant overall PIT effect with both reward cues eliciting reward-seeking on test relative to the unpaired cue. Pavlovian extinction substantially reduced this effect, with the extinguished reward cue eliciting less reward-seeking than the non-extinguished reward cue. Most interestingly, extinction of cue-elicited reward-seeking was sensitive to renewal, with extinction less effective for reducing PIT when conducted in a different context. These findings have important implications for extinction-based interventions for reducing maladaptive reward-seeking in practice. Copyright © 2016 Elsevier Ltd. All rights reserved.

Teaching children with autism spectrum disorder to tact olfactory stimuli.

Science.gov (United States)

Dass, Tina K; Kisamore, April N; Vladescu, Jason C; Reeve, Kenneth F; Reeve, Sharon A; Taylor-Santa, Catherine

2018-05-28

Research on tact acquisition by children with autism spectrum disorder (ASD) has often focused on teaching participants to tact visual stimuli. It is important to evaluate procedures for teaching tacts of nonvisual stimuli (e.g., olfactory, tactile). The purpose of the current study was to extend the literature on secondary target instruction and tact training by evaluating the effects of a discrete-trial instruction procedure involving (a) echoic prompts, a constant prompt delay, and error correction for primary targets; (b) inclusion of secondary target stimuli in the consequent portion of learning trials; and (c) multiple exemplar training on the acquisition of item tacts of olfactory stimuli, emergence of category tacts of olfactory stimuli, generalization of category tacts, and emergence of category matching, with three children diagnosed with ASD. Results showed that all participants learned the item and category tacts following teaching, participants demonstrated generalization across category tacts, and category matching emerged for all participants. © 2018 Society for the Experimental Analysis of Behavior.

Minocycline inhibits D-amphetamine-elicited action potential bursts in a central snail neuron.

Science.gov (United States)

Chen, Y-H; Lin, P-L; Wong, R-W; Wu, Y-T; Hsu, H-Y; Tsai, M-C; Lin, M-J; Hsu, Y-C; Lin, C-H

2012-10-25

Minocycline is a second-generation tetracycline that has been reported to have powerful neuroprotective properties. In our previous studies, we found that d-amphetamine (AMPH) elicited action potential bursts in an identifiable RP4 neuron of the African snail, Achatina fulica Ferussac. This study sought to determine the effects of minocycline on the AMPH-elicited action potential pattern changes in the central snail neuron, using the two-electrode voltage clamping method. Extracellular application of AMPH at 300 μM elicited action potential bursts in the RP4 neuron. Minocycline dose-dependently (300-900 μM) inhibited the action potential bursts elicited by AMPH. The inhibitory effects of minocycline on AMPH-elicited action potential bursts were restored by forskolin (50 μM), an adenylate cyclase activator, and by dibutyryl cAMP (N(6),2'-O-Dibutyryladenosine 3',5'-cyclic monophosphate; 1mM), a membrane-permeable cAMP analog. Co-administration of forskolin (50 μM) plus tetraethylammonium chloride (TEA; 5mM) or co-administration of TEA (5mM) plus dibutyryl cAMP (1mM) also elicited action potential bursts, which were prevented and inhibited by minocycline. In addition, minocycline prevented and inhibited forskolin (100 μM)-elicited action potential bursts. Notably, TEA (50mM)-elicited action potential bursts in the RP4 neuron were not affected by minocycline. Minocycline did not affect steady-state outward currents of the RP4 neuron. However, minocycline did decrease the AMPH-elicited steady-state current changes. Similarly, minocycline decreased the effects of forskolin-elicited steady-state current changes. Pretreatment with H89 (N-[2-(p-Bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide dihydrochloride; 10 μM), a protein kinase A inhibitor, inhibited AMPH-elicited action potential bursts and decreased AMPH-elicited steady-state current changes. These results suggest that the cAMP-protein kinase A signaling pathway and the steady-state current are involved in

The Reinforcing Event (RE) Menu

Science.gov (United States)

Addison, Roger M.; Homme, Lloyd E.

1973-01-01

A motivational system, the Contingency Management System, uses contracts in which some amount of defined task behavior is demanded for some interval of reinforcing event. The Reinforcing Event Menu, a list of high probability reinforcing behaviors, is used in the system as a prompting device for the learner and as an aid for the administrator in…

Pedunculopontine tegmental nucleus lesions impair stimulus--reward learning in autoshaping and conditioned reinforcement paradigms.

Science.gov (United States)

Inglis, W L; Olmstead, M C; Robbins, T W

2000-04-01

The role of the pedunculopontine tegmental nucleus (PPTg) in stimulus-reward learning was assessed by testing the effects of PPTg lesions on performance in visual autoshaping and conditioned reinforcement (CRf) paradigms. Rats with PPTg lesions were unable to learn an association between a conditioned stimulus (CS) and a primary reward in either paradigm. In the autoshaping experiment, PPTg-lesioned rats approached the CS+ and CS- with equal frequency, and the latencies to respond to the two stimuli did not differ. PPTg lesions also disrupted discriminated approaches to an appetitive CS in the CRf paradigm and completely abolished the acquisition of responding with CRf. These data are discussed in the context of a possible cognitive function of the PPTg, particularly in terms of lesion-induced disruptions of attentional processes that are mediated by the thalamus.

Increased BOLD Signals Elicited by High Gamma Auditory Stimulation of the Left Auditory Cortex in Acute State Schizophrenia

Directory of Open Access Journals (Sweden)

Hironori Kuga, M.D.

2016-10-01

We acquired BOLD responses elicited by click trains of 20, 30, 40 and 80-Hz frequencies from 15 patients with acute episode schizophrenia (AESZ, 14 symptom-severity-matched patients with non-acute episode schizophrenia (NASZ, and 24 healthy controls (HC, assessed via a standard general linear-model-based analysis. The AESZ group showed significantly increased ASSR-BOLD signals to 80-Hz stimuli in the left auditory cortex compared with the HC and NASZ groups. In addition, enhanced 80-Hz ASSR-BOLD signals were associated with more severe auditory hallucination experiences in AESZ participants. The present results indicate that neural over activation occurs during 80-Hz auditory stimulation of the left auditory cortex in individuals with acute state schizophrenia. Given the possible association between abnormal gamma activity and increased glutamate levels, our data may reflect glutamate toxicity in the auditory cortex in the acute state of schizophrenia, which might lead to progressive changes in the left transverse temporal gyrus.

Steel fiber reinforced concrete

International Nuclear Information System (INIS)

Baloch, S.U.

2005-01-01

Steel-Fiber Reinforced Concrete is constructed by adding short fibers of small cross-sectional size .to the fresh concrete. These fibers reinforce the concrete in all directions, as they are randomly oriented. The improved mechanical properties of concrete include ductility, impact-resistance, compressive, tensile and flexural strength and abrasion-resistance. These uniqlte properties of the fiber- reinforcement can be exploited to great advantage in concrete structural members containing both conventional bar-reinforcement and steel fibers. The improvements in mechanical properties of cementitious materials resulting from steel-fiber reinforcement depend on the type, geometry, volume fraction and material-properties of fibers, the matrix mix proportions and the fiber-matrix interfacial bond characteristics. Effects of steel fibers on the mechanical properties of concrete have been investigated in this paper through a comprehensive testing-programme, by varying the fiber volume fraction and the aspect-ratio (Lid) of fibers. Significant improvements are observed in compressive, tensile, flexural strength and impact-resistance of concrete, accompanied by marked improvement in ductility. optimum fiber-volume fraction and aspect-ratio of steel fibers is identified. Test results are analyzed in details and relevant conclusions drawn. The research is finally concluded with future research needs. (author)

A method to elicit beliefs as most likely intervals

NARCIS (Netherlands)

Schlag, K.H.; van der Weele, J.J.

2015-01-01

We show how to elicit the beliefs of an expert in the form of a "most likely interval", a set of future outcomes that are deemed more likely than any other outcome. Our method, called the Most Likely Interval elicitation rule (MLI), asks the expert for an interval and pays according to how well the

Corrosion of reinforcement bars in steel ibre reinforced concrete structures

DEFF Research Database (Denmark)

Solgaard, Anders Ole Stubbe

and the influence of steel fibres on initiation and propagation of cracks in concrete. Moreover, the impact of fibres on corrosion-induced cover cracking was covered. The impact of steel fibres on propagation of reinforcement corrosion was investigated through studies of their impact on the electrical resistivity...... of concrete, which is known to affect the corrosion process of embedded reinforcement. The work concerning the impact of steel fibres on initiation and propagation of cracks was linked to corrosion initiation and propagation of embedded reinforcement bars via additional studies. Cracks in the concrete cover...... are known to alter the ingress rate of depassivating substances and thereby influence the corrosion process. The Ph.D. study covered numerical as well as experimental studies. Electrochemically passive steel fibres are electrically isolating thus not changing the electrical resistivity of concrete, whereas...

Generating stimuli for neuroscience using PsychoPy

Directory of Open Access Journals (Sweden)

Jonathan W Peirce

2009-01-01

Full Text Available PsychoPy is a software library written in Python, using OpenGL to generate very precise visual stimuli on standard personal computers. It is designed to allow the construction of as wide a variety of neuroscience experiments as possible, with the least effort. By writing scripts in standard Python syntax users can generate an enormous variety of visual and auditory stimuli and can interact with a wide range of external hardware (enabling its use in fMRI, EEG, MEG etc.. The structure of scripts is simple and intuitive. As a result, new experiments can be written very quickly, and trying to understand a previously written script is easy, even with minimal code comments. PsychoPy can also generate movies and image sequences to be used in demos or simulated neuroscience experiments. This paper describes the range of tools and stimuli that it provides and the environment in which experiments are conducted.

Algorithms for Reinforcement Learning

CERN Document Server

Szepesvari, Csaba

2010-01-01

Reinforcement learning is a learning paradigm concerned with learning to control a system so as to maximize a numerical performance measure that expresses a long-term objective. What distinguishes reinforcement learning from supervised learning is that only partial feedback is given to the learner about the learner's predictions. Further, the predictions may have long term effects through influencing the future state of the controlled system. Thus, time plays a special role. The goal in reinforcement learning is to develop efficient learning algorithms, as well as to understand the algorithms'

Interpretative bias in spider phobia: Perception and information processing of ambiguous schematic stimuli.

Science.gov (United States)

Haberkamp, Anke; Schmidt, Filipp

2015-09-01

This study investigates the interpretative bias in spider phobia with respect to rapid visuomotor processing. We compared perception, evaluation, and visuomotor processing of ambiguous schematic stimuli between spider-fearful and control participants. Stimuli were produced by gradually morphing schematic flowers into spiders. Participants rated these stimuli related to their perceptual appearance and to their feelings of valence, disgust, and arousal. Also, they responded to the same stimuli within a response priming paradigm that measures rapid motor activation. Spider-fearful individuals showed an interpretative bias (i.e., ambiguous stimuli were perceived as more similar to spiders) and rated spider-like stimuli as more unpleasant, disgusting, and arousing. However, we observed no differences between spider-fearful and control participants in priming effects for ambiguous stimuli. For non-ambiguous stimuli, we observed a similar enhancement for phobic pictures as has been reported previously for natural images. We discuss our findings with respect to the visual representation of morphed stimuli and to perceptual learning processes. Copyright © 2015 Elsevier B.V. All rights reserved.

Presentation of Aural Stimuli to Newborns and Premature Infants: An Audiological Perspective.

Science.gov (United States)

Cassidy

1999-01-01

The purpose of this study was twofold: (a) to examine extant research in the field of music with premature and full term infants in order to identify protocols being used in the presentation of musical stimuli to neonates and (b) to use knowledge gleaned from audiology as a basis for suggesting a standardized protocol for use of musical stimuli with infants. Articles considered appropriate for inclusion in the analysis met the following criteria: (a) presented data for the effects of music on a dependent measure, (b) had subjects who were identified as either premature or term newborns receiving treatment after birth and prior to discharge from the hospital, and (c) used music for some or all of the aural stimuli. Articles (N = 20) were categorized by demographic information, types of aural stimuli, independent variables, dependent measures, and protocol used to present the musical stimuli. Of primary importance to this study was the protocol used in each study to present musical stimuli. Data regarding total duration of stimuli per day, longest duration of stimuli per day, method of stimuli presentation, placement of speakers, decibel level of stimuli, and where;he decibel level was measured reveal that there is no standard protocol being followed with regard to the presentation of aural stimuli. Recommendations include future research on (a) determining a minimum gestational age where music therapy may be appropriate, (b) determining the frequency spectrum perceived by a premature infant, (c) determining the decibel levels reaching the ear drum and assessing appropriate levels for minimum stimulation with maximum results, and (d) carefully considering the method of stimulus presentation as it will have an impact on the decibel level reaching the ear drum of these infants.

Storage of feature conjunctions in transient auditory memory.

Science.gov (United States)

Gomes, H; Bernstein, R; Ritter, W; Vaughan, H G; Miller, J

1997-11-01

The purpose of this study was to determine whether feature conjunctions are stored in transient auditory memory. The mismatch negativity (MMN), an event-related potential that is elicited by stimuli that differ from a series of preceding stimuli, was used in this endeavour. A tone that differed from the preceding series of stimuli in the conjunction of two of its features, both present in preceding stimuli but in different combinations, was found to elicit the MMN. The data are interpreted to indicate that information about the conjunction of features is stored in the memory.

Positive mood broadens visual attention to positive stimuli.

Science.gov (United States)

Wadlinger, Heather A; Isaacowitz, Derek M

2006-03-01

In an attempt to investigate the impact of positive emotions on visual attention within the context of Fredrickson's (1998) broaden-and-build model, eye tracking was used in two studies to measure visual attentional preferences of college students (n=58, n=26) to emotional pictures. Half of each sample experienced induced positive mood immediately before viewing slides of three similarly-valenced images, in varying central-peripheral arrays. Attentional breadth was determined by measuring the percentage viewing time to peripheral images as well as by the number of visual saccades participants made per slide. Consistent with Fredrickson's theory, the first study showed that individuals induced into positive mood fixated more on peripheral stimuli than did control participants; however, this only held true for highly-valenced positive stimuli. Participants under induced positive mood also made more frequent saccades for slides of neutral and positive valence. A second study showed that these effects were not simply due to differences in emotional arousal between stimuli. Selective attentional broadening to positive stimuli may act both to facilitate later building of resources as well as to maintain current positive affective states.

Testing the race model inequality in redundant stimuli with variable onset asynchrony

DEFF Research Database (Denmark)

Gondan, Matthias

2009-01-01

distributions of response times for the single-modality stimuli. It has been derived for synchronous stimuli and for stimuli with stimulus onset asynchrony (SOA). In most experiments with asynchronous stimuli, discrete SOA values are chosen and the race model inequality is separately tested for each SOA. Due...... to SOAs at which the violation of the race model prediction is expected to be large. In addition, the method enables data analysis for experiments in which stimuli are presented with SOA from a continuous distribution rather than in discrete steps.......In speeded response tasks with redundant signals, parallel processing of the signals is tested by the race model inequality. This inequality states that given a race of two signals, the cumulative distribution of response times for redundant stimuli never exceeds the sum of the cumulative...

Generating Stimuli for Neuroscience Using PsychoPy

OpenAIRE

Peirce, Jonathan W.

2009-01-01

PsychoPy is a software library written in Python, using OpenGL to generate very precise visual stimuli on standard personal computers. It is designed to allow the construction of as wide a variety of neuroscience experiments as possible, with the least effort. By writing scripts in standard Python syntax users can generate an enormous variety of visual and auditory stimuli and can interact with a wide range of external hardware (enabling its use in fMRI, EEG, MEG etc.). The structure of scrip...

Effects of response-independent stimuli on fixed-interval and fixed-ratio performance of rats: a model for stressful disruption of cyclical eating patterns.

Science.gov (United States)

Reed, Phil

2011-03-01

Binge eating is often associated with stress-induced disruption of typical eating patterns. Three experiments were performed with the aim of developing a potential model for this effect by investigating the effect of presenting response-independent stimuli on rats' lever-pressing for food reinforcement during both fixed-interval (FI) and fixed-ratio (FR) schedules of reinforcement. In Experiment 1, a response-independent brief tone (500-ms, 105-dB, broadband, noisy signal, ranging up to 16 kHz, with spectral peaks at 3 and 500 Hz) disrupted the performance on an FI 60-s schedule. Responding with the response-independent tone was more vigorous than in the absence of the tone. This effect was replicated in Experiment 2 using a within-subject design, but no such effect was noted when a light was employed as a disrupter. In Experiment 3, a 500-ms tone, but not a light, had a similar effect on rats' performance on FR schedules. This tone-induced effect may represent a release from response-inhibition produced by an aversive event. The implications of these results for modeling binge eating are discussed.

Continuous Reinforced Concrete Beams

DEFF Research Database (Denmark)

Hoang, Cao Linh; Nielsen, Mogens Peter

1996-01-01

This report deals with stress and stiffness estimates of continuous reinforced concrete beams with different stiffnesses for negative and positive moments e.g. corresponding to different reinforcement areas in top and bottom. Such conditions are often met in practice.The moment distribution...

Stimuli-responsive liquid crystalline materials

NARCIS (Netherlands)

Debije, M.G.; Schenning, A.P.H.J.; Hashmi, Saleem

2016-01-01

Stimuli-responsive materials which respond to triggers from the environment by changing their properties are one of the focal points in materials science. For precise functional properties, well-defined hierarchically ordered supramolecular materials are crucial. The self-assembly of liquid crystals

Modelling reinforcement corrosion in concrete

DEFF Research Database (Denmark)

Michel, Alexander; Geiker, Mette Rica; Stang, Henrik

2012-01-01

A physio-chemical model for the simulation of reinforcement corrosion in concrete struc-tures was developed. The model allows for simulation of initiation and subsequent propaga-tion of reinforcement corrosion. Corrosion is assumed to be initiated once a defined critical chloride threshold......, a numerical example is pre-sented, that illustrates the formation of corrosion cells as well as propagation of corrosion in a reinforced concrete structure....

The Reinforcement Learning Competition 2014

OpenAIRE

Dimitrakakis, Christos; Li, Guangliang; Tziortziotis, Nikoalos

2014-01-01

Reinforcement learning is one of the most general problems in artificial intelligence. It has been used to model problems in automated experiment design, control, economics, game playing, scheduling and telecommunications. The aim of the reinforcement learning competition is to encourage the development of very general learning agents for arbitrary reinforcement learning problems and to provide a test-bed for the unbiased evaluation of algorithms.

Parametric Analysis of Presession Exposure to Edible and Nonedible Stimuli

Science.gov (United States)

Sy, Jolene R.; Borrero, John C.

2009-01-01

We assessed the effects of individually defined small, medium, and large periods of presession access to edible and nonedible reinforcers on response rates during sessions in which responding produced access to identical reinforcers. Any presession access to an edible reinforcer decreased response rates for 1 participant, and small and medium…

Origins of food reinforcement in infants12345

Science.gov (United States)

Kong, Kai Ling; Feda, Denise M; Eiden, Rina D; Epstein, Leonard H

2015-01-01

Background: Rapid weight gain in infancy is associated with a higher risk of obesity in children and adults. A high relative reinforcing value of food is cross-sectionally related to obesity; lean children find nonfood alternatives more reinforcing than do overweight/obese children. However, to our knowledge, there is no research on how and when food reinforcement develops. Objective: This study was designed to assess whether the reinforcing value of food and nonfood alternatives could be tested in 9- to 18-mo-old infants and whether the reinforcing value of food and nonfood alternatives is differentially related to infant weight status. Design: Reinforcing values were assessed by using absolute progressive ratio schedules of reinforcement, with presentation of food and nonfood alternatives counterbalanced in 2 separate studies. Two nonfood reinforcers [Baby Einstein–Baby MacDonald shows (study 1, n = 27) or bubbles (study 2, n = 30)] were tested against the baby’s favorite food. Food reinforcing ratio (FRR) was quantified by measuring the reinforcing value of food (Food Pmax) in proportion to the total reinforcing value of food and a nonfood alternative (DVD Pmax or BUB Pmax). Results: Greater weight-for-length z score was associated with a greater FRR of a favorite food in study 1 (FRR-DVD) (r = 0.60, P positively associated with FRR-DVD (r = 0.57, P = 0.009) and FRR-BUB (r = 0.37, P = 0.047). Conclusions: Our newly developed paradigm, which tested 2 different nonfood alternatives, demonstrated that lean infants find nonfood alternatives more reinforcing than do overweight/obese infants. This observation suggests that strengthening the alternative reinforcers may have a protective effect against childhood obesity. This research was registered at clinicaltrials.gov as NCT02229552. PMID:25733636

Analyzing the user behavior towards Electronic Commerce stimuli

OpenAIRE

Carlota Lorenzo-Romero; María-del-Carmen Alarcón-del-Amo

2016-01-01

Based on the Stimulus-Organism-Response paradigm this research analyzes the main differences between the effects of two types of web technologies: Verbal web technology (i.e. navigational structure as utilitarian stimulus) versus nonverbal web technology (music and presentation of products as hedonic stimuli). Specific webmosphere stimuli have not been examined yet as separate variables and their impact on internal and behavioral responses seems unknown. Therefore, the objective of this resea...

Haptic and Audio-visual Stimuli: Enhancing Experiences and Interaction

NARCIS (Netherlands)

Nijholt, Antinus; Dijk, Esko O.; Lemmens, Paul M.C.; Luitjens, S.B.

2010-01-01

The intention of the symposium on Haptic and Audio-visual stimuli at the EuroHaptics 2010 conference is to deepen the understanding of the effect of combined Haptic and Audio-visual stimuli. The knowledge gained will be used to enhance experiences and interactions in daily life. To this end, a

Exploring Visuomotor Priming Following Biological and Non-Biological Stimuli

Science.gov (United States)

Gowen, E.; Bradshaw, C.; Galpin, A.; Lawrence, A.; Poliakoff, E.

2010-01-01

Observation of human actions influences the observer's own motor system, termed visuomotor priming, and is believed to be caused by automatic activation of mirror neurons. Evidence suggests that priming effects are larger for biological (human) as opposed to non-biological (object) stimuli and enhanced when viewing stimuli in mirror compared to…

Application of expert elicitation techniques in human reliability, assessment

International Nuclear Information System (INIS)

Sanyasi Rao, V.V.S.; Saraf, R.K.; Ghosh, A.K.; Kushwaha, H.S.

2006-01-01

Expert elicitation techniques are being used, in the area of technological forecasting, in estimating data needed for analysis when it is either difficult to arrive at the data by experimental means or when it is quite involved to plan and conduct the experiment. In this study, expert elicitation techniques are applied to the evaluation of the frequencies of the various accident sequences that can result from the initiating event (IE) 'High Pressure Process Water (HPPW) system failure' in typical Indian Pressurised Heavy Water Reactor (IPHWR) of the older generation. The Operating Procedure under Emergency Conditions (OPEC) for this IE involves human actions according to a pre-defined procedure. The Human Error Probabilities for all these human actions are obtained using expert elicitation techniques. These techniques aim at eliciting the opinion of the experts in the area of interest with regard to the issue in question. The uncertainty is analysed by employing the measure of dissonance and the most probable range of human error probabilities are arrived at by maximizing this measure. These values are combined using the same procedures mentioned above to yield a distribution representing the uncertainty associated with the predictions. (author)

Do community and autonomy moral violations elicit different emotions?

Science.gov (United States)

Kollareth, Dolichan; Kikutani, Mariko; Shirai, Mariko; Russell, James A

2018-06-11

According to one important set of theories, different domains of immorality are linked to different discrete emotions-panculturally. Violations against the community elicit contempt, whereas violations against an individual elicit anger. To test this theory, American, Indian and Japanese participants (N = 480) indicated contempt and anger reactions (with verbal rating and face selection) to both the types of immorality. To remedy method problems in previous research, community and autonomy violations were created for the same story-frame, by varying the target to be either the community or an individual. Community and autonomy violations did not differ significantly in the emotion elicited: overall, both types of violations elicited more anger than contempt (and more negative emotion of any kind than positive emotion). By verbal rating, Americans and Indians reported more anger than contempt for both types of violation, whereas Japanese reported more contempt than anger for both types. By face selection, the three cultural groups selected anger more than contempt for both types of violation. The results speak against defining distinct domains of morality by their association with distinct emotions. © 2018 International Union of Psychological Science.

Elicitation threshold of cobalt chloride

DEFF Research Database (Denmark)

Fischer, Louise A; Johansen, Jeanne D; Voelund, Aage

2016-01-01

: On the basis of five included studies, the ED10 values of aqueous cobalt chloride ranged between 0.0663 and 1.95 µg cobalt/cm(2), corresponding to 30.8-259 ppm. CONCLUSIONS: Our analysis provides an overview of the doses of cobalt that are required to elicit allergic cobalt contactdermatitis in sensitized...

Effect of hybrid fiber reinforcement on the cracking process in fiber reinforced cementitious composites

DEFF Research Database (Denmark)

Pereira, Eduardo B.; Fischer, Gregor; Barros, Joaquim A.O.

2012-01-01

The simultaneous use of different types of fibers as reinforcement in cementitious matrix composites is typically motivated by the underlying principle of a multi-scale nature of the cracking processes in fiber reinforced cementitious composites. It has been hypothesized that while undergoing...... tensile deformations in the composite, the fibers with different geometrical and mechanical properties restrain the propagation and further development of cracking at different scales from the micro- to the macro-scale. The optimized design of the fiber reinforcing systems requires the objective...... materials is carried out by assessing directly their tensile stress-crack opening behavior. The efficiency of hybrid fiber reinforcements and the multi-scale nature of cracking processes are discussed based on the experimental results obtained, as well as the micro-mechanisms underlying the contribution...

Dopamine modulates reward system activity during subconscious processing of sexual stimuli.

Science.gov (United States)

Oei, Nicole Y L; Rombouts, Serge Arb; Soeter, Roelof P; van Gerven, Joop M; Both, Stephanie

2012-06-01

Dopaminergic medication influences conscious processing of rewarding stimuli, and is associated with impulsive-compulsive behaviors, such as hypersexuality. Previous studies have shown that subconscious subliminal presentation of sexual stimuli activates brain areas known to be part of the 'reward system'. In this study, it was hypothesized that dopamine modulates activation in key areas of the reward system, such as the nucleus accumbens, during subconscious processing of sexual stimuli. Young healthy males (n=53) were randomly assigned to two experimental groups or a control group, and were administered a dopamine antagonist (haloperidol), a dopamine agonist (levodopa), or placebo. Brain activation was assessed during a backward-masking task with subliminally presented sexual stimuli. Results showed that levodopa significantly enhanced the activation in the nucleus accumbens and dorsal anterior cingulate when subliminal sexual stimuli were shown, whereas haloperidol decreased activations in those areas. Dopamine thus enhances activations in regions thought to regulate 'wanting' in response to potentially rewarding sexual stimuli that are not consciously perceived. This running start of the reward system might explain the pull of rewards in individuals with compulsive reward-seeking behaviors such as hypersexuality and patients who receive dopaminergic medication.

Stimuli-responsive magnetic particles for biomedical applications.

Science.gov (United States)

Medeiros, S F; Santos, A M; Fessi, H; Elaissari, A

2011-01-17

In recent years, magnetic nanoparticles have been studied due to their potential applications as magnetic carriers in biomedical area. These materials have been increasingly exploited as efficient delivery vectors, leading to opportunities of use as magnetic resonance imaging (MRI) agents, mediators of hyperthermia cancer treatment and in targeted therapies. Much attention has been also focused on "smart" polymers, which are able to respond to environmental changes, such as changes in the temperature and pH. In this context, this article reviews the state-of-the art in stimuli-responsive magnetic systems for biomedical applications. The paper describes different types of stimuli-sensitive systems, mainly temperature- and pH sensitive polymers, the combination of this characteristic with magnetic properties and, finally, it gives an account of their preparation methods. The article also discusses the main in vivo biomedical applications of such materials. A survey of the recent literature on various stimuli-responsive magnetic gels in biomedical applications is also included. Copyright © 2010 Elsevier B.V. All rights reserved.

Analyzing the User Behavior toward Electronic Commerce Stimuli

OpenAIRE

Lorenzo-Romero, Carlota; Alarcón-del-Amo, María-del-Carmen; Gómez-Borja, Miguel-Ángel

2016-01-01

Based on the Stimulus-Organism-Response paradigm this research analyzes the main differences between the effects of two types of web technologies: Verbal web technology (i.e., navigational structure as utilitarian stimulus) versus non-verbal web technology (music and presentation of products as hedonic stimuli). Specific webmosphere stimuli have not been examined yet as separate variables and their impact on internal and behavioral responses seems unknown. Therefore, the objective of this res...

Modeling Behavioral Experiment Interaction and Environmental Stimuli for a Synthetic C. elegans

Directory of Open Access Journals (Sweden)

Andoni Mujika

2017-12-01

Full Text Available This paper focusses on the simulation of the neural network of the Caenorhabditis elegans living organism, and more specifically in the modeling of the stimuli applied within behavioral experiments and the stimuli that is generated in the interaction of the C. elegans with the environment. To the best of our knowledge, all efforts regarding stimuli modeling for the C. elegansare focused on a single type of stimulus, which is usually tested with a limited subnetwork of the C. elegansneural system. In this paper, we follow a different approach where we model a wide-range of different stimuli, with more flexible neural network configurations and simulations in mind. Moreover, we focus on the stimuli sensation by different types of sensory organs or various sensory principles of the neurons. As part of this work, most common stimuli involved in behavioral assays have been modeled. It includes models for mechanical, thermal, chemical, electrical and light stimuli, and for proprioception-related self-sensed information exchange with the neural network. The developed models have been implemented and tested with the hardware-based Si elegans simulation platform.

Do emotional stimuli enhance or impede recall relative to neutral stimuli? An investigation of two "false memory" tasks.

Science.gov (United States)

Monds, Lauren A; Paterson, Helen M; Kemp, Richard I

2017-09-01

Many eyewitness memory situations involve negative and distressing events; however, many studies investigating "false memory" phenomena use neutral stimuli only. The aim of the present study was to determine how both the Deese-Roediger-McDermott (DRM) procedure and the Misinformation Effect Paradigm tasks were related to each other using distressing and neutral stimuli. Participants completed the DRM (with negative and neutral word lists) and viewed a distressing or neutral film. Misinformation for the film was introduced and memory was assessed. Film accuracy and misinformation susceptibility were found to be greater for those who viewed the distressing film relative to the neutral film. Accuracy responses on both tasks were related, however, susceptibility to the DRM illusion and Misinformation Effect were not. The misinformation findings support the Paradoxical Negative Emotion (PNE) hypothesis that negative stimuli will lead to remembering more accurate details but also greater likelihood of memory distortion. However, the PNE hypothesis was not supported for the DRM results. The findings also suggest that the DRM and Misinformation tasks are not equivalent and may have differences in underlying mechanisms. Future research should focus on more ecologically valid methods of assessing false memory.

Bitter taste stimuli induce differential neural codes in mouse brain.

Directory of Open Access Journals (Sweden)

David M Wilson

Full Text Available A growing literature suggests taste stimuli commonly classified as "bitter" induce heterogeneous neural and perceptual responses. Here, the central processing of bitter stimuli was studied in mice with genetically controlled bitter taste profiles. Using these mice removed genetic heterogeneity as a factor influencing gustatory neural codes for bitter stimuli. Electrophysiological activity (spikes was recorded from single neurons in the nucleus tractus solitarius during oral delivery of taste solutions (26 total, including concentration series of the bitter tastants quinine, denatonium benzoate, cycloheximide, and sucrose octaacetate (SOA, presented to the whole mouth for 5 s. Seventy-nine neurons were sampled; in many cases multiple cells (2 to 5 were recorded from a mouse. Results showed bitter stimuli induced variable gustatory activity. For example, although some neurons responded robustly to quinine and cycloheximide, others displayed concentration-dependent activity (p<0.05 to quinine but not cycloheximide. Differential activity to bitter stimuli was observed across multiple neurons recorded from one animal in several mice. Across all cells, quinine and denatonium induced correlated spatial responses that differed (p<0.05 from those to cycloheximide and SOA. Modeling spatiotemporal neural ensemble activity revealed responses to quinine/denatonium and cycloheximide/SOA diverged during only an early, at least 1 s wide period of the taste response. Our findings highlight how temporal features of sensory processing contribute differences among bitter taste codes and build on data suggesting heterogeneity among "bitter" stimuli, data that challenge a strict monoguesia model for the bitter quality.

Auditory-visual aversive stimuli modulate the conscious experience of fear.

Science.gov (United States)

Taffou, Marine; Guerchouche, Rachid; Drettakis, George; Viaud-Delmon, Isabelle

2013-01-01

In a natural environment, affective information is perceived via multiple senses, mostly audition and vision. However, the impact of multisensory information on affect remains relatively undiscovered. In this study, we investigated whether the auditory-visual presentation of aversive stimuli influences the experience of fear. We used the advantages of virtual reality to manipulate multisensory presentation and to display potentially fearful dog stimuli embedded in a natural context. We manipulated the affective reactions evoked by the dog stimuli by recruiting two groups of participants: dog-fearful and non-fearful participants. The sensitivity to dog fear was assessed psychometrically by a questionnaire and also at behavioral and subjective levels using a Behavioral Avoidance Test (BAT). Participants navigated in virtual environments, in which they encountered virtual dog stimuli presented through the auditory channel, the visual channel or both. They were asked to report their fear using Subjective Units of Distress. We compared the fear for unimodal (visual or auditory) and bimodal (auditory-visual) dog stimuli. Dog-fearful participants as well as non-fearful participants reported more fear in response to bimodal audiovisual compared to unimodal presentation of dog stimuli. These results suggest that fear is more intense when the affective information is processed via multiple sensory pathways, which might be due to a cross-modal potentiation. Our findings have implications for the field of virtual reality-based therapy of phobias. Therapies could be refined and improved by implicating and manipulating the multisensory presentation of the feared situations.

A novel dual-wavelength laser stimulator to elicit transient and tonic nociceptive stimulation.

Science.gov (United States)

Dong, Xiaoxi; Liu, Tianjun; Wang, Han; Yang, Jichun; Chen, Zhuying; Hu, Yong; Li, Yingxin

2017-07-01

This study aimed to develop a new laser stimulator to elicit both transient and sustained heat stimulation with a dual-wavelength laser system as a tool for the investigation of both transient and tonic experimental models of pain. The laser stimulator used a 980-nm pulsed laser to generate transient heat stimulation and a 1940-nm continuous-wave (CW) laser to provide sustained heat stimulation. The laser with 980-nm wavelength can elicit transient pain with less thermal injury, while the 1940-nm CW laser can effectively stimulate both superficial and deep nociceptors to elicit tonic pain. A proportional integral-derivative (PID) temperature feedback control system was implemented to ensure constancy of temperature during heat stimulation. The performance of this stimulator was evaluated by in vitro and in vivo animal experiments. In vitro experiments on totally 120 specimens fresh pig skin included transient heat stimulation by 980-nm laser (1.5 J, 10 ms), sustained heat stimulation by 1940-nm laser (50-55 °C temperature control mode or 1.5 W, 5 min continuous power supply), and the combination of transient/sustained heat stimulation by dual lasers (1.5 J, 10 ms, 980-nm pulse laser, and 1940-nm laser with 50-55 °C temperature control mode). Hemoglobin brushing and wind-cooling methods were tested to find better stimulation model. A classic tail-flick latency (TFL) experiment with 20 Wistar rats was used to evaluate the in vivo efficacy of transient and tonic pain stimulation with 15 J, 100 ms 980-nm single laser pulse, and 1.5 W constant 1940-nm laser power. Ideal stimulation parameters to generate transient pain were found to be a 26.6 °C peak temperature rise and 0.67 s pain duration. In our model of tonic pain, 5 min of tonic stimulation produced a temperature change of 53.7 ± 1.3 °C with 1.6 ± 0.2% variation. When the transient and tonic stimulation protocols were combined, no significant difference was observed depending on the order

Seismic Retrofitting: Reinforced Concrete (RC shear wall versus Reinforcement of RC element by Carbon Fiber Reinforced Polymer (CFRP using PUSHOVER analysis

Directory of Open Access Journals (Sweden)

Yahya RIYAD

2016-12-01

Full Text Available Seismic retrofitting of constructions vulnerable to earthquakes is a current problem of great political and social relevance. During the last sixty years, moderate to severe earthquakes have occurred in Morocco (specifically in Agadir 1960 and Hoceima 2004. Such events have clearly shown the vulnerability of the building stock in particular and of the built environment in general. Hence, it is very much essential to retrofit the vulnerable building to cope up for the next damaging earthquake. In this paper, the focus will be on a comparative study between two techniques of seismic retrofitting, the first one is a reinforcement using carbon fiber reinforced polymer (CFRP applied to RC elements by bonding , and the second one is a reinforcement with a shear wall. For this study, we will use a non-linear static analysis -also known as Pushover analysis - on a reinforced concrete structure consisting of beams and columns, and composed from eight storey with a gross area of 240 m², designed conforming to the Moroccan Seismic code[1].

Stimuli responsive nanomaterials for controlled release applications

KAUST Repository

Li, Song

2012-01-01

The controlled release of therapeutics has been one of the major challenges for scientists and engineers during the past three decades. Coupled with excellent biocompatibility profiles, various nanomaterials have showed great promise for biomedical applications. Stimuli-responsive nanomaterials guarantee the controlled release of cargo to a given location, at a specific time, and with an accurate amount. In this review, we have combined the major stimuli that are currently used to achieve the ultimate goal of controlled and targeted release by "smart" nanomaterials. The most heavily explored strategies include (1) pH, (2) enzymes, (3) redox, (4) magnetic, and (5) light-triggered release.

[The P300-based brain-computer interface: presentation of the complex "flash + movement" stimuli].

Science.gov (United States)

Ganin, I P; Kaplan, A Ia

2014-01-01

The P300 based brain-computer interface requires the detection of P300 wave of brain event-related potentials. Most of its users learn the BCI control in several minutes and after the short classifier training they can type a text on the computer screen or assemble an image of separate fragments in simple BCI-based video games. Nevertheless, insufficient attractiveness for users and conservative stimuli organization in this BCI may restrict its integration into real information processes control. At the same time initial movement of object (motion-onset stimuli) may be an independent factor that induces P300 wave. In current work we checked the hypothesis that complex "flash + movement" stimuli together with drastic and compact stimuli organization on the computer screen may be much more attractive for user while operating in P300 BCI. In 20 subjects research we showed the effectiveness of our interface. Both accuracy and P300 amplitude were higher for flashing stimuli and complex "flash + movement" stimuli compared to motion-onset stimuli. N200 amplitude was maximal for flashing stimuli, while for "flash + movement" stimuli and motion-onset stimuli it was only a half of it. Similar BCI with complex stimuli may be embedded into compact control systems requiring high level of user attention under impact of negative external effects obstructing the BCI control.

Improvement of Requirement Elicitation Process through Cognitive Psychology

Directory of Open Access Journals (Sweden)

Sana Fatima

2017-06-01

Full Text Available Proper requirement elicitation is necessary for client satisfaction along with the overall project success, but requirement engineers face problems in understanding user requirements and the users of the required system fail to make requirement engineering team understand what they actually want. It is then responsibility of requirement engineers to extract proper requirements. This paper discusses how to use cognitive psychology and learning style models (LSM to understand the psychology of clients. Moreover, it also discusses usage of proper elicitation technique according to one’s learning style and gather the right requirements.

Roll motion stimuli : sensory conflict, perceptual weighting and motion sickness

NARCIS (Netherlands)

Graaf, B. de; Bles, W.; Bos, J.E.

1998-01-01

In an experiment with seventeen subjects interactions of visual roll motion stimuli and vestibular body tilt stimuli were examined in determining the subjective vertical. Interindi-vidual differences in weighting the visual information were observed, but in general visual and vestibular responses

TRAC-Monterey FY16 Work Program Development and Report of Research Elicitation

Science.gov (United States)

2016-01-01

any changes to priorities or additional projects that require immediate research. Work Program; Research Elicitation Unclassified UU UU UU UU 35 MAJ...conduct analysis for the Army. 1 Marks, Chris, Nesbitt, Peter. TRAC FY14 Research Requirements Elicitation . Technical Report TRAC-M-TM-13-059. 700 Dyer... Requirements Elicitation Interviews Interview Guide: 1. Describe a research requirement in the areas of topics, techniques, and methodologies. 2

A Dual-Stimuli-Responsive Sodium-Bromine Battery with Ultrahigh Energy Density.

Science.gov (United States)

Wang, Faxing; Yang, Hongliu; Zhang, Jian; Zhang, Panpan; Wang, Gang; Zhuang, Xiaodong; Cuniberti, Gianaurelio; Feng, Xinliang

2018-06-01

Stimuli-responsive energy storage devices have emerged for the fast-growing popularity of intelligent electronics. However, all previously reported stimuli-responsive energy storage devices have rather low energy densities (energy density, electrochromic effect, and fast thermal response is demonstrated. Remarkably, the fabricated Na//Br 2 battery exhibits a large operating voltage of 3.3 V and an energy density up to 760 Wh kg -1 , which outperforms those for the state-of-the-art stimuli-responsive electrochemical energy storage devices. This work offers a promising approach for designing multi-stimuli-responsive and high-energy rechargeable batteries without sacrificing the electrochemical performance. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Neurophysiological evidence (ERPs) for hemispheric processing of facial expressions of emotions: Evidence from whole face and chimeric face stimuli.

Science.gov (United States)

Damaskinou, Nikoleta; Watling, Dawn

2018-05-01

This study was designed to investigate the patterns of electrophysiological responses of early emotional processing at frontocentral sites in adults and to explore whether adults' activation patterns show hemispheric lateralization for facial emotion processing. Thirty-five adults viewed full face and chimeric face stimuli. After viewing two faces, sequentially, participants were asked to decide which of the two faces was more emotive. The findings from the standard faces and the chimeric faces suggest that emotion processing is present during the early phases of face processing in the frontocentral sites. In particular, sad emotional faces are processed differently than neutral and happy (including happy chimeras) faces in these early phases of processing. Further, there were differences in the electrode amplitudes over the left and right hemisphere, particularly in the early temporal window. This research provides supporting evidence that the chimeric face test is a test of emotion processing that elicits right hemispheric processing.

Pattern visual evoked potentials elicited by organic electroluminescence screen.

Science.gov (United States)

Matsumoto, Celso Soiti; Shinoda, Kei; Matsumoto, Harue; Funada, Hideaki; Sasaki, Kakeru; Minoda, Haruka; Iwata, Takeshi; Mizota, Atsushi

2014-01-01

To determine whether organic electroluminescence (OLED) screens can be used as visual stimulators to elicit pattern-reversal visual evoked potentials (p-VEPs). Checkerboard patterns were generated on a conventional cathode-ray tube (S710, Compaq Computer Co., USA) screen and on an OLED (17 inches, 320 × 230 mm, PVM-1741, Sony, Tokyo, Japan) screen. The time course of the luminance changes of each monitor was measured with a photodiode. The p-VEPs elicited by these two screens were recorded from 15 eyes of 9 healthy volunteers (22.0 ± 0.8 years). The OLED screen had a constant time delay from the onset of the trigger signal to the start of the luminescence change. The delay during the reversal phase from black to white for the pattern was 1.0 msec on the cathode-ray tube (CRT) screen and 0.5 msec on the OLED screen. No significant differences in the amplitudes of P100 and the implicit times of N75 and P100 were observed in the p-VEPs elicited by the CRT and the OLED screens. The OLED screen can be used as a visual stimulator to elicit p-VEPs; however the time delay and the specific properties in the luminance change must be taken into account.

FOAM CONCRETE REINFORCEMENT BY BASALT FIBRES

Directory of Open Access Journals (Sweden)

Zhukov Aleksey Dmitrievich

2012-10-01

Full Text Available The authors demonstrate that the foam concrete performance can be improved by dispersed reinforcement, including methods that involve basalt fibres. They address the results of the foam concrete modeling technology and assess the importance of technology-related parameters. Reinforcement efficiency criteria are also provided in the article. Dispersed reinforcement improves the plasticity of the concrete mix and reduces the settlement crack formation rate. Conventional reinforcement that involves metal laths and rods demonstrates its limited application in the production of concrete used for thermal insulation and structural purposes. Dispersed reinforcement is preferable. This technology contemplates the infusion of fibres into porous mixes. Metal, polymeric, basalt and glass fibres are used as reinforcing components. It has been identified that products reinforced by polypropylene fibres demonstrate substantial abradability and deformability rates even under the influence of minor tensile stresses due to the low adhesion strength of polypropylene in the cement matrix. The objective of the research was to develop the type of polypropylene of D500 grade that would demonstrate the operating properties similar to those of Hebel and Ytong polypropylenes. Dispersed reinforcement was performed by the basalt fibre. This project contemplates an autoclave-free technology to optimize the consumption of electricity. Dispersed reinforcement is aimed at the reduction of the block settlement in the course of hardening at early stages of their operation, the improvement of their strength and other operating properties. Reduction in the humidity rate of the mix is based on the plasticizing properties of fibres, as well as the application of the dry mineralization method. Selection of optimal parameters of the process-related technology was performed with the help of G-BAT-2011 Software, developed at Moscow State University of Civil Engineering. The authors also

Attentional load modulates responses of human primary visual cortex to invisible stimuli.

Science.gov (United States)

Bahrami, Bahador; Lavie, Nilli; Rees, Geraint

2007-03-20

Visual neuroscience has long sought to determine the extent to which stimulus-evoked activity in visual cortex depends on attention and awareness. Some influential theories of consciousness maintain that the allocation of attention is restricted to conscious representations [1, 2]. However, in the load theory of attention [3], competition between task-relevant and task-irrelevant stimuli for limited-capacity attention does not depend on conscious perception of the irrelevant stimuli. The critical test is whether the level of attentional load in a relevant task would determine unconscious neural processing of invisible stimuli. Human participants were scanned with high-field fMRI while they performed a foveal task of low or high attentional load. Irrelevant, invisible monocular stimuli were simultaneously presented peripherally and were continuously suppressed by a flashing mask in the other eye [4]. Attentional load in the foveal task strongly modulated retinotopic activity evoked in primary visual cortex (V1) by the invisible stimuli. Contrary to traditional views [1, 2, 5, 6], we found that availability of attentional capacity determines neural representations related to unconscious processing of continuously suppressed stimuli in human primary visual cortex. Spillover of attention to cortical representations of invisible stimuli (under low load) cannot be a sufficient condition for their awareness.

A history of alternative reinforcement reduces stimulus generalization of ethanol-seeking in a rat recovery model

Science.gov (United States)

Ginsburg, Brett C.; Lamb, R. J.

2012-01-01

BACKGROUND Longer periods of recovery reduce the likelihood of relapse, which may be due to a reduced ability of various stimuli to occasion alcohol or drug seeking. However, this hypothesis remains largely uninvestigated. METHODS Here we assessed the ability of intermediate stimuli to occasion responding for ethanol in rats trained to discriminate an 8kHz tone signaling a food fixed-ratio (FR) of 5 and an ethanol FR5, from a 16kHz tone signaling a food FR150 and ethanol FR5. In the presence of the 8kHz tone responding for food predominates, and in the presence of the 16 kHz tone, responding for ethanol predominates. RESULTS In the context of alternation between these conditions, varying the tone from 8 to 16kHz produces a graded increase in ethanol (versus food) responding, consistent with a stimulus generalization function. A recent history of responding under food-predominant choice conditions, either during the test session or in the four sessions that precede it shifts the generalization function downwards. Extending this history to nine sessions shifts the curve further downwards. The stimulus generalization function was similar in a separate group, trained with different relative ratios for food and ethanol, but with similar behavioral allocation under each discriminative stimulus. Finally, withholding access to food and ethanol for 4 or 16 sessions did not affect the stimulus generalization gradient. CONCLUSION These results suggest that longer histories of reinforced alternative behavior might reduce the likelihood of relapse by decreasing the control exerted over alcohol- or drug-seeking by stimuli similar to those that previously occasioned alcohol- or drug-seeking. PMID:23122598

The possibility of using high strength reinforced concrete

International Nuclear Information System (INIS)

Miura, Nobuaki

1991-01-01

There is recently much research about and developments in reinforced concrete using high strength concrete and reinforcement. As a result, some high-rise buildings and nuclear buildings have been constructed with such concrete. Reinforced concrete will be stronger in the future, but there is a limit to its strength defined by the character of the materials and also by the character of the reinforced concrete members made of the concrete and reinforcement. This report describes the merits and demerits of using high strength reinforced concrete. (author)

Reinforced concrete wall under hydrogen detonation

International Nuclear Information System (INIS)

Saarenheimo, A.

2000-11-01

The structural integrity of a reinforced concrete wall in the BWR reactor building under hydrogen detonation conditions has been analysed. Of particular interest is whether the containment integrity can be jeopardised by an external hydrogen detonation. The load carrying capacity of a reinforced concrete wall was studied. The detonation pressure loads were estimated with computerised hand calculations assuming a direct initiation of detonation and applying the strong explosion theory. The results can be considered as rough and conservative estimates for the first shock pressure impact induced by a reflecting detonation wave. Structural integrity may be endangered due to slow pressurisation or dynamic impulse loads associated with local detonations. The static pressure following the passage of a shock front may be relatively high, thus this static or slowly decreasing pressure after a detonation may damage the structure severely. The mitigating effects of the opening of a door on pressure history and structural response were also studied. The non-linear behaviour of the wall was studied under detonations corresponding a detonable hydrogen mass of 0.5 kg and 1.428 kg. Non-linear finite element analyses of the reinforced concrete structure were carried out by the ABAQUS/Explicit program. The reinforcement and its non-linear material behaviour and the tensile cracking of concrete were modelled. Reinforcement was defined as layers of uniformly spaced reinforcing bars in shell elements. In these studies the surrounding structures of the non-linearly modelled reinforced concrete wall were modelled using idealised boundary conditions. Especially concrete cracking and yielding of the reinforcement was monitored during the numerical simulation. (au)

Heightened attentional capture by visual food stimuli in Anorexia Nervosa

NARCIS (Netherlands)

Neimeijer, Renate A.M.; Roefs, Anne; de Jong, Peter J.

The present study was designed to test the hypothesis that anorexia nervosa (AN) patients are relatively insensitive to the attentional capture of visual food stimuli. Attentional avoidance of food might help AN patients to prevent more elaborate processing of food stimuli and the subsequent

Processing of natural temporal stimuli by macaque retinal ganglion cells

NARCIS (Netherlands)

Hateren, J.H. van; Rüttiger, L.; Lee, B.B.

2002-01-01

This study quantifies the performance of primate retinal ganglion cells in response to natural stimuli. Stimuli were confined to the temporal and chromatic domains and were derived from two contrasting environments, one typically northern European and the other a flower show. The performance of the

Under pressure: adolescent substance users show exaggerated neural processing of aversive interoceptive stimuli

NARCIS (Netherlands)

Berk, L.; Stewart, J.L.; May, A.C.; Wiers, R.W.; Davenport, P.W.; Paulus, M.P.; Tapert, S.F.

2015-01-01

Aims: Adolescents with substance use disorders (SUD) exhibit hyposensitivity to pleasant internally generated (interoceptive) stimuli and hypersensitivity to external rewarding stimuli. It is unclear whether similar patterns exist for aversive interoceptive stimuli. We compared activation in the

On the weld strength of in situ tape placed reinforcements on weave reinforced structures

NARCIS (Netherlands)

Grouve, Wouter Johannes Bernardus; Warnet, Laurent; Rietman, Bert; Akkerman, Remko

2012-01-01

Unidirectionally reinforced thermoplastic tapes were welded onto woven fabric reinforced laminates using a laser assisted tape placement process. A mandrel peel setup was used to quantify the interfacial fracture toughness between the tape and the laminate as a measure for weld strength. The tape

Reinforcement Learning State-of-the-Art

CERN Document Server

Wiering, Marco

2012-01-01

Reinforcement learning encompasses both a science of adaptive behavior of rational beings in uncertain environments and a computational methodology for finding optimal behaviors for challenging problems in control, optimization and adaptive behavior of intelligent agents. As a field, reinforcement learning has progressed tremendously in the past decade. The main goal of this book is to present an up-to-date series of survey articles on the main contemporary sub-fields of reinforcement learning. This includes surveys on partially observable environments, hierarchical task decompositions, relational knowledge representation and predictive state representations. Furthermore, topics such as transfer, evolutionary methods and continuous spaces in reinforcement learning are surveyed. In addition, several chapters review reinforcement learning methods in robotics, in games, and in computational neuroscience. In total seventeen different subfields are presented by mostly young experts in those areas, and together the...

Attentional capture by social stimuli in young infants

Directory of Open Access Journals (Sweden)

Maxie eGluckman

2013-08-01

Full Text Available We investigated the possibility that a range of social stimuli capture the attention of 6-month-old infants when in competition with other non-face objects. Infants viewed a series of six-item arrays in which one target item was a face, body part, or animal as their eye movements were recorded. Stimulus arrays were also processed for relative salience of each item in terms of color, luminance, and amount of contour. Targets were rarely the most visually salient items in the arrays, yet infants’ first looks toward all three target types were above chance, and dwell times for targets exceeded other stimulus types. Girls looked longer at faces than did boys, but there were no sex differences for other stimuli. These results are interpreted in a context of learning to discriminate between different classes of animate stimuli, perhaps in line with affordances for social interaction, and origins of sex differences in social attention.

Rule-violations sensitise towards negative and authority-related stimuli.

Science.gov (United States)

Wirth, Robert; Foerster, Anna; Rendel, Hannah; Kunde, Wilfried; Pfister, Roland

2018-05-01

Rule violations have usually been studied from a third-person perspective, identifying situational factors that render violations more or less likely. A first-person perspective of the agent that actively violates the rules, on the other hand, is only just beginning to emerge. Here we show that committing a rule violation sensitises towards subsequent negative stimuli as well as subsequent authority-related stimuli. In a Prime-Probe design, we used an instructed rule-violation task as the Prime and a word categorisation task as the Probe. Also, we employed a control condition that used a rule inversion task as the Prime (instead of rule violations). Probe targets were categorised faster after a violation relative to after a rule-based response if they related to either, negative valence or authority. Inversions, however, primed only negative stimuli and did not accelerate the categorisation of authority-related stimuli. A heightened sensitivity towards authority-related targets thus seems to be specific to rule violations. A control experiment showed that these effects cannot be explained in terms of semantic priming. Therefore, we propose that rule violations necessarily activate authority-related representations that make rule violations qualitatively different from simple rule inversions.

Cortical oscillations modulated by congruent and incongruent audiovisual stimuli.

Science.gov (United States)

Herdman, A T; Fujioka, T; Chau, W; Ross, B; Pantev, C; Picton, T W

2004-11-30

Congruent or incongruent grapheme-phoneme stimuli are easily perceived as one or two linguistic objects. The main objective of this study was to investigate the changes in cortical oscillations that reflect the processing of congruent and incongruent audiovisual stimuli. Graphemes were Japanese Hiragana characters for four different vowels (/a/, /o/, /u/, and /i/). They were presented simultaneously with their corresponding phonemes (congruent) or non-corresponding phonemes (incongruent) to native-speaking Japanese participants. Participants' reaction times to the congruent audiovisual stimuli were significantly faster by 57 ms as compared to reaction times to incongruent stimuli. We recorded the brain responses for each condition using a whole-head magnetoencephalograph (MEG). A novel approach to analysing MEG data, called synthetic aperture magnetometry (SAM), was used to identify event-related changes in cortical oscillations involved in audiovisual processing. The SAM contrast between congruent and incongruent responses revealed greater event-related desynchonization (8-16 Hz) bilaterally in the occipital lobes and greater event-related synchronization (4-8 Hz) in the left transverse temporal gyrus. Results from this study further support the concept of interactions between the auditory and visual sensory cortices in multi-sensory processing of audiovisual objects.

Attentional Capture by Emotional Stimuli Is Modulated by Semantic Processing

Science.gov (United States)

Huang, Yang-Ming; Baddeley, Alan; Young, Andrew W.

2008-01-01

The attentional blink paradigm was used to examine whether emotional stimuli always capture attention. The processing requirement for emotional stimuli in a rapid sequential visual presentation stream was manipulated to investigate the circumstances under which emotional distractors capture attention, as reflected in an enhanced attentional blink…

Entropy-optimal weight constraint elicitation with additive multi-attribute utility models

NARCIS (Netherlands)

Valkenhoef , van Gert; Tervonen, Tommi

2016-01-01

We consider the elicitation of incomplete preference information for the additive utility model in terms of linear constraints on the weights. Eliciting incomplete preferences using holistic pair-wise judgments is convenient for the decision maker, but selecting the best pair-wise comparison is

Eliciting Subjective Probabilities with Binary Lotteries

DEFF Research Database (Denmark)

Harrison, Glenn W.; Martínez-Correa, Jimmy; Swarthout, J. Todd

objective probabilities. Drawing a sample from the same subject population, we find evidence that the binary lottery procedure induces linear utility in a subjective probability elicitation task using the Quadratic Scoring Rule. We also show that the binary lottery procedure can induce direct revelation...

Facilitating tolerance of delayed reinforcement during functional communication training.

Science.gov (United States)

Fisher, W W; Thompson, R H; Hagopian, L P; Bowman, L G; Krug, A

2000-01-01

Few clinical investigations have addressed the problem of delayed reinforcement. In this investigation, three individuals whose destructive behavior was maintained by positive reinforcement were treated using functional communication training (FCT) with extinction (EXT). Next, procedures used in the basic literature on delayed reinforcement and self-control (reinforcer delay fading, punishment of impulsive responding, and provision of an alternative activity during reinforcer delay) were used to teach participants to tolerate delayed reinforcement. With the first case, reinforcer delay fading alone was effective at maintaining low rates of destructive behavior while introducing delayed reinforcement. In the second case, the addition of a punishment component reduced destructive behavior to near-zero levels and facilitated reinforcer delay fading. With the third case, reinforcer delay fading was associated with increases in masturbation and head rolling, but prompting and praising the individual for completing work during the delay interval reduced all problem behaviors and facilitated reinforcer delay fading.

Reinforced Conductive Polyaniline-Paper Composites

Directory of Open Access Journals (Sweden)

Jinhua Yan

2015-05-01

Full Text Available A method for direct aniline interfacial polymerization on polyamideamine-epichlorohydrin (PAE-reinforced paper substrate is introduced in this paper. Cellulose-based papers with and without reinforcement were considered. The polyaniline (PANI-paper composites had surface resistivity lower than 100 Ω/sq after more than 3 polymerizations. Their mechanical strength and thermal stability were analyzed by tensile tests and thermogravimetric analysis (TGA. Fourier transform infrared (FTIR results revealed that there was strong interaction between NH groups in aniline monomers and OH groups in fibers, which did not disappear until after 3 polymerizations. Scanning electron microscopy (SEM and field emission (FE SEM images showed morphological differences between composites using reinforced and untreated base papers. Conductive composites made with PAE-reinforced base paper had both good thermal stability and good mechanical strength, with high conductivity and a smaller PANI amount.

Sample Size for Measuring Grammaticality in Preschool Children from Picture-Elicited Language Samples

Science.gov (United States)

Eisenberg, Sarita L.; Guo, Ling-Yu

2015-01-01

Purpose: The purpose of this study was to investigate whether a shorter language sample elicited with fewer pictures (i.e., 7) would yield a percent grammatical utterances (PGU) score similar to that computed from a longer language sample elicited with 15 pictures for 3-year-old children. Method: Language samples were elicited by asking forty…

Superelastic SMA–FRP composite reinforcement for concrete structures

International Nuclear Information System (INIS)

Wierschem, Nicholas; Andrawes, Bassem

2010-01-01

For many years there has been interest in using fiber-reinforced polymers (FRPs) as reinforcement in concrete structures. Unfortunately, due to their linear elastic behavior, FRP reinforcing bars are never considered for structural damping or dynamic applications. With the aim of improving the ductility and damping capability of concrete structures reinforced with FRP reinforcement, this paper studies the application of SMA–FRP, a relatively novel type of composite reinforced with superelastic shape memory alloy (SMA) wires. The cyclic tensile behavior of SMA–FRP composites are studied experimentally and analytically. Tests of SMA–FRP composite coupons are conducted to determine their constitutive behavior. The experimental results are used to develop and calibrate a uniaxial SMA–FRP analytical model. Parametric and case studies are performed to determine the efficacy of the SMA–FRP reinforcement in concrete structures and the key factors governing its behavior. The results show significant potential for SMA–FRP reinforcement to improve the ductility and damping of concrete structures while still maintaining its elastic characteristic, typical of FRP reinforcement

Positive behavioral contrast across food and alcohol reinforcers.

OpenAIRE

McSweeney, F K; Melville, C L; Higa, J

1988-01-01

The present study examined behavioral contrast during concurrent and multiple schedules that provided food and alcohol reinforcers. Concurrent-schedule contrast occurred in the responding reinforced by food when alcohol reinforcers were removed. It also occurred in the responding reinforced by alcohol when food was removed. Multiple-schedule contrast appeared for food when alcohol reinforcers were removed, but not for alcohol when food was removed. These results show that behavioral contrast ...

Perceptual load modifies processing of unattended stimuli both in the presence and absence of attended stimuli.

Science.gov (United States)

Couperus, J W

2010-11-26

This study explored effects of perceptual load on stimulus processing in the presence and absence of an attended stimulus. Participants were presented with a bilateral or unilateral display and asked to perform a discrimination task at either low or high perceptual load. Electrophysiological responses to stimuli were then compared at the P100 and N100. As in previous studies, perceptual load modified processing of attended and unattended stimuli seen at occipital scalp sites. Moreover, perceptual load modulated attention effects when the attended stimulus was presented at high perceptual load for unilateral displays. However, this was not true when the attended and unattended stimulus appeared simultaneously in bilateral displays. Instead, only a main effect of perceptual load was found. Reductions in processing contralateral to the unattended stimulus at the N100 provide support for Lavie's (1995) theory of selective attention. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Eliciting Information on Sensitive Matters Without Inviting ...

Indian Academy of Sciences (India)

Eliciting Information on Sensitive Matters. Without Inviting Respondents' ... methods based on Randomized Response tech- niques. ... while collecting data on some sensitive issues are well ..... Suppose there is an association of professionals.

Learning to trade via direct reinforcement.

Science.gov (United States)

Moody, J; Saffell, M

2001-01-01

We present methods for optimizing portfolios, asset allocations, and trading systems based on direct reinforcement (DR). In this approach, investment decision-making is viewed as a stochastic control problem, and strategies are discovered directly. We present an adaptive algorithm called recurrent reinforcement learning (RRL) for discovering investment policies. The need to build forecasting models is eliminated, and better trading performance is obtained. The direct reinforcement approach differs from dynamic programming and reinforcement algorithms such as TD-learning and Q-learning, which attempt to estimate a value function for the control problem. We find that the RRL direct reinforcement framework enables a simpler problem representation, avoids Bellman's curse of dimensionality and offers compelling advantages in efficiency. We demonstrate how direct reinforcement can be used to optimize risk-adjusted investment returns (including the differential Sharpe ratio), while accounting for the effects of transaction costs. In extensive simulation work using real financial data, we find that our approach based on RRL produces better trading strategies than systems utilizing Q-learning (a value function method). Real-world applications include an intra-daily currency trader and a monthly asset allocation system for the S&P 500 Stock Index and T-Bills.

Enhancement of shear strength and ductility for reinforced concrete wide beams due to web reinforcement

Directory of Open Access Journals (Sweden)

M. Said

2013-12-01

Full Text Available The shear behavior of reinforced concrete wide beams was investigated. The experimental program consisted of nine beams of 29 MPa concrete strength tested with a shear span-depth ratio equal to 3.0. One of the tested beams had no web reinforcement as a control specimen. The flexure mode of failure was secured for all of the specimens to allow for shear mode of failure. The key parameters covered in this investigation are the effect of the existence, spacing, amount and yield stress of the vertical stirrups on the shear capacity and ductility of the tested wide beams. The study shows that the contribution of web reinforcement to the shear capacity is significant and directly proportional to the amount and spacing of the shear reinforcement. The increase in the shear capacity ranged from 32% to 132% for the range of the tested beams compared with the control beam. High grade steel was more effective in the contribution of the shear strength of wide beams. Also, test results demonstrate that the shear reinforcement significantly enhances the ductility of the wide beams. In addition, shear resistances at failure recorded in this study are compared to the analytical strengths calculated according to the current Egyptian Code and the available international codes. The current study highlights the need to include the contribution of shear reinforcement in the Egyptian Code requirements for shear capacity of wide beams.

Fibre Reinforced Polymer Composites as Internal and External Reinforcements for Building Elements

Directory of Open Access Journals (Sweden)

Cătălin Banu

2008-01-01

Full Text Available During the latest decades fibre reinforced polymer (FRP composite materials have proven valuable properties and suitable to be used in construction of new buildings and in upgrading the existing ones. These materials have covered the road from research laboratory and demonstration projects to implementation in actual structures. Nowadays the civil and structural engineering communities are about to commence the stage in which the use of FRP composites is becoming a routine similar to that of traditional material such as concrete, masonry and wood. Two main issues are presented in this paper, the use of FRP composite materials for new structural members (internal reinforcements and strengthening of existing members (externally bonded reinforcements. The advantages and disadvantages as well as the problems and constraints associated with both issues are discussed in detail mainly related to concrete members.

Simulation of Stimuli-Responsive Polymer Networks

Directory of Open Access Journals (Sweden)

Thomas Gruhn

2013-11-01

Full Text Available The structure and material properties of polymer networks can depend sensitively on changes in the environment. There is a great deal of progress in the development of stimuli-responsive hydrogels for applications like sensors, self-repairing materials or actuators. Biocompatible, smart hydrogels can be used for applications, such as controlled drug delivery and release, or for artificial muscles. Numerical studies have been performed on different length scales and levels of details. Macroscopic theories that describe the network systems with the help of continuous fields are suited to study effects like the stimuli-induced deformation of hydrogels on large scales. In this article, we discuss various macroscopic approaches and describe, in more detail, our phase field model, which allows the calculation of the hydrogel dynamics with the help of a free energy that considers physical and chemical impacts. On a mesoscopic level, polymer systems can be modeled with the help of the self-consistent field theory, which includes the interactions, connectivity, and the entropy of the polymer chains, and does not depend on constitutive equations. We present our recent extension of the method that allows the study of the formation of nano domains in reversibly crosslinked block copolymer networks. Molecular simulations of polymer networks allow the investigation of the behavior of specific systems on a microscopic scale. As an example for microscopic modeling of stimuli sensitive polymer networks, we present our Monte Carlo simulations of a filament network system with crosslinkers.

Cognitive behavioural therapy attenuates the enhanced early facial stimuli processing in social anxiety disorders: an ERP investigation.

Science.gov (United States)

Cao, Jianqin; Liu, Quanying; Li, Yang; Yang, Jun; Gu, Ruolei; Liang, Jin; Qi, Yanyan; Wu, Haiyan; Liu, Xun

2017-07-28

Previous studies of patients with social anxiety have demonstrated abnormal early processing of facial stimuli in social contexts. In other words, patients with social anxiety disorder (SAD) tend to exhibit enhanced early facial processing when compared to healthy controls. Few studies have examined the temporal electrophysiological event-related potential (ERP)-indexed profiles when an individual with SAD compares faces to objects in SAD. Systematic comparisons of ERPs to facial/object stimuli before and after therapy are also lacking. We used a passive visual detection paradigm with upright and inverted faces/objects, which are known to elicit early P1 and N170 components, to study abnormal early face processing and subsequent improvements in this measure in patients with SAD. Seventeen patients with SAD and 17 matched control participants performed a passive visual detection paradigm task while undergoing EEG. The healthy controls were compared to patients with SAD pre-therapy to test the hypothesis that patients with SAD have early hypervigilance to facial cues. We compared patients with SAD before and after therapy to test the hypothesis that the early hypervigilance to facial cues in patients with SAD can be alleviated. Compared to healthy control (HC) participants, patients with SAD had more robust P1-N170 slope but no amplitude effects in response to both upright and inverted faces and objects. Interestingly, we found that patients with SAD had reduced P1 responses to all objects and faces after therapy, but had selectively reduced N170 responses to faces, and especially inverted faces. Interestingly, the slope from P1 to N170 in patients with SAD was flatter post-therapy than pre-therapy. Furthermore, the amplitude of N170 evoked by the facial stimuli was correlated with scores on the interaction anxiousness scale (IAS) after therapy. Our results did not provide electrophysiological support for the early hypervigilance hypothesis in SAD to faces, but

Pattern Visual Evoked Potentials Elicited by Organic Electroluminescence Screen

Directory of Open Access Journals (Sweden)

Celso Soiti Matsumoto

2014-01-01

Full Text Available Purpose. To determine whether organic electroluminescence (OLED screens can be used as visual stimulators to elicit pattern-reversal visual evoked potentials (p-VEPs. Method. Checkerboard patterns were generated on a conventional cathode-ray tube (S710, Compaq Computer Co., USA screen and on an OLED (17 inches, 320 × 230 mm, PVM-1741, Sony, Tokyo, Japan screen. The time course of the luminance changes of each monitor was measured with a photodiode. The p-VEPs elicited by these two screens were recorded from 15 eyes of 9 healthy volunteers (22.0 ± 0.8 years. Results. The OLED screen had a constant time delay from the onset of the trigger signal to the start of the luminescence change. The delay during the reversal phase from black to white for the pattern was 1.0 msec on the cathode-ray tube (CRT screen and 0.5 msec on the OLED screen. No significant differences in the amplitudes of P100 and the implicit times of N75 and P100 were observed in the p-VEPs elicited by the CRT and the OLED screens. Conclusion. The OLED screen can be used as a visual stimulator to elicit p-VEPs; however the time delay and the specific properties in the luminance change must be taken into account.

Strength Characteristics of Reinforced Sandy Soil

OpenAIRE

S. N. Bannikov; Mahamed Al Fayez

2005-01-01

Laboratory tests on determination of reinforced sandy soil strength characteristics (angle of internal friction, specific cohesive force) have been carried out with the help of a specially designed instrument and proposed methodology. Analysis of the obtained results has revealed that cohesive forces are brought about in reinforced sandy soil and an angle of internal soil friction becomes larger in comparison with non-reinforced soil.

Analytical, Numerical and Experimental Examination of Reinforced Composites Beams Covered with Carbon Fiber Reinforced Plastic

Science.gov (United States)

Kasimzade, A. A.; Tuhta, S.

2012-03-01

In the article, analytical, numerical (Finite Element Method) and experimental investigation results of beam that was strengthened with fiber reinforced plastic-FRP composite has been given as comparative, the effect of FRP wrapping number to the maximum load and moment capacity has been evaluated depending on this results. Carbon FRP qualitative dependences have been occurred between wrapping number and beam load and moment capacity for repair-strengthen the reinforced concrete beams with carbon fiber. Shown possibilities of application traditional known analysis programs, for the analysis of Carbon Fiber Reinforced Plastic (CFRP) strengthened structures.

Producing Durable Continuously Reinforced Concrete Pavement using Glass-ceramic Coated Reinforcing Steel

Science.gov (United States)

2010-02-01

reinforcement if the enamel is broken  Embedded cement grains hydrate if enamel is cracked to self-heal with the formation of calcium silicate hydrate Goal...Reinforced Concrete Pavement The 600% volume change in the iron to iron oxide formation put the concrete in tension and it cracks an spalls BUILDING...corrodes prematurely and delaminates the pavement  Moisture and chlorides can move through the natural porosity of concrete and the cracks in the

Constitutive model for reinforced concrete

NARCIS (Netherlands)

Feenstra, P.H.; Borst, de R.

1995-01-01

A numerical model is proposed for reinforced-concrete behavior that combines the commonly accepted ideas from modeling plain concrete, reinforcement, and interaction behavior in a consistent manner. The behavior of plain concrete is govern by fracture-energy-level-based formulation both in tension

Tangible Reinforcers: Bonuses or Bribes?

Science.gov (United States)

O'Leary, K. Daniel; And Others

1972-01-01

Objections to the use of tangible reinforcers, such as prizes, candy, cigarettes, and money, are discussed. Treatment programs using tangible reinforcers are recommended as powerful modifers of behavior to be implemented only after less powerful means of modification have been tried. (Author)

Happiness takes you right: the effect of emotional stimuli on line bisection.

Science.gov (United States)

Cattaneo, Zaira; Lega, Carlotta; Boehringer, Jana; Gallucci, Marcello; Girelli, Luisa; Carbon, Claus-Christian

2014-01-01

Emotion recognition is mediated by a complex network of cortical and subcortical areas, with the two hemispheres likely being differently involved in processing positive and negative emotions. As results on valence-dependent hemispheric specialisation are quite inconsistent, we carried out three experiments with emotional stimuli with a task being sensitive to measure specific hemispheric processing. Participants were required to bisect visual lines that were delimited by emotional face flankers, or to haptically bisect rods while concurrently listening to emotional vocal expressions. We found that prolonged (but not transient) exposition to concurrent happy stimuli significantly shifted the bisection bias to the right compared to both sad and neutral stimuli, indexing a greater involvement of the left hemisphere in processing of positively connoted stimuli. No differences between sad and neutral stimuli were observed across the experiments. In sum, our data provide consistent evidence in favour of a greater involvement of the left hemisphere in processing positive emotions and suggest that (prolonged) exposure to stimuli expressing happiness significantly affects allocation of (spatial) attentional resources, regardless of the sensory (visual/auditory) modality in which the emotion is perceived and space is explored (visual/haptic).

TEACHING SELF-CONTROL WITH QUALITATIVELY DIFFERENT REINFORCERS

OpenAIRE

Passage, Michael; Tincani, Matt; Hantula, Donald A.

2012-01-01

This study examined the effectiveness of using qualitatively different reinforcers to teach self-control to an adolescent boy who had been diagnosed with an intellectual disability. First, he was instructed to engage in an activity without programmed reinforcement. Next, he was instructed to engage in the activity under a two-choice fixed-duration schedule of reinforcement. Finally, he was exposed to self-control training, during which the delay to a more preferred reinforcer was initially sh...

PABRE-Proj: applying patterns in requirements elicitation

OpenAIRE

Palomares Bonache, Cristina; Quer Bosor, Maria Carme; Franch Gutiérrez, Javier

2013-01-01

Software requirement patterns have been proposed as a type of artifact for fostering requirements reuse. In this paper, we present PABRE-Proj, a tool aimed at supporting requirements elicitation and specification. Peer Reviewed

Multisensory stimuli improve relative localisation judgments compared to unisensory auditory or visual stimuli

OpenAIRE

Bizley, Jennifer; Wood, Katherine; Freeman, Laura

2018-01-01

Observers performed a relative localisation task in which they reported whether the second of two sequentially presented signals occurred to the left or right of the first. Stimuli were detectability-matched auditory, visual, or auditory-visual signals and the goal was to compare changes in performance with eccentricity across modalities. Visual performance was superior to auditory at the midline, but inferior in the periphery, while auditory-visual performance exceeded both at all locations....

New bio-active, antimicrobial and adherent coatings of nanostructured carbon double-reinforced with silver and silicon by Matrix-Assisted Pulsed Laser Evaporation for medical applications

Science.gov (United States)

Duta, L.; Ristoscu, C.; Stan, G. E.; Husanu, M. A.; Besleaga, C.; Chifiriuc, M. C.; Lazar, V.; Bleotu, C.; Miculescu, F.; Mihailescu, N.; Axente, E.; Badiceanu, M.; Bociaga, D.; Mihailescu, Ion N.

2018-05-01

We report on Matrix-Assisted Pulsed Laser Evaporation (MAPLE) deposition of Carbon thin films, simple or reinforced with intended concentrations of Ag and Si. A KrF∗ (λ = 248 nm, τFWHM ≤ 25 ns, ν = 10 Hz) excimer laser was used for irradiation. The effect of a post-deposition thermal treatment in vacuum was studied. Besides detailed morphological, compositional, structural and pull-out adherence characterizations, the potential of the carbonaceous films for medical applications was investigated in vitro by anti-biofilm and cytocompatibility assays. The microscopic images evidenced no delaminations. Micro-Raman spectroscopy revealed a graphitization tendency depending on preparation conditions, thermal treatment and reinforcing agents' presence. Adherence values improved considerably after thermal treatment. In vitro biological evaluation showed that the films containing ∼1.85 at.% Ag were non-cytotoxic for MG63 cells, while eliciting a limited antimicrobial activity. The increase of Ag content to 3.6 at.% results in a significant enhancement of antimicrobial activity, whilst maintaining the cytotoxic action and adherence characteristics at acceptable levels. We propose a new class of metamaterials based on C reinforced with Ag and Si obtained by MAPLE for medical applications, i.e. the prevention and treatment of various infections associated with biofilms developed on implants and other medical equipments.

Employers' readiness for the mother-friendly workplace: an elicitation study.

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Bai, Yeon K; Wunderlich, Shahla M; Weinstock, Marni

2012-10-01

Currently over half of mothers of infants under 1-year-old are in the workforce in the United States. These women face challenges to continue breastfeeding when they return to work 3 to 6 months post-partum. This study explored the perspectives of employers on mother-friendly environments to assess their readiness to provide breastfeeding accommodation using the elicitation under the theory of planned behaviour. Researchers conducted phone/in-person interviews with a convenient sample of 20 human resource managers from companies that had 500 or more employees in the New York metropolitan area in 2009. Content analyses identified the common concepts that represent underlying beliefs of the constructs of the theory. The demography of the participants is 40% male and 80% White, with mean ages of 34.3±8.5 years. 'Happy employees' and 'high retention rate and improved loyalty' were the most frequently mentioned (95%) benefits to the company (behavioural beliefs). Supporters of a mother-friendly environment (normative beliefs) in the workplace included 'mothers and expectant mothers (70%)', and 'managers supervising women and new mothers (55%)'. Most frequently mentioned company drawbacks (control beliefs) were 'not cost effective (65%)' and 'time consuming (65%)', followed by 'perception of special favours for some (50%)'. Workplace breastfeeding promotion efforts can be successful by reinforcing positive beliefs and addressing the challenges associated with implementation of breastfeeding accommodation through education and other incentives such as recognition of model companies and tax breaks. The identified beliefs provide a basis for the development of a quantitative instrument to study workplace breastfeeding support further. © 2011 Blackwell Publishing Ltd.

Opposing Subjective Temporal Experiences in Response to Unpredictable and Predictable Fear-Relevant Stimuli

Directory of Open Access Journals (Sweden)

Qian Cui

2018-03-01

Full Text Available Previous studies have found that the durations of fear-relevant stimuli were overestimated compared to those of neutral stimuli, even when the fear-relevant stimuli were only anticipated. The current study aimed to investigate the effect of the predictability of fear-relevant stimuli on sub-second temporal estimations. In Experiments 1a and 1b, a randomized design was employed to render the emotional valence of each trial unpredictable. In Experiments 2a and 2b, we incorporated a block design and a cueing paradigm, respectively, to render the emotional stimuli predictable. Compared with the neutral condition, the estimated blank interval was judged as being shorter under the unpredictable fear-relevant condition, while it was judged as being longer under the predictable fear-relevant condition. In other words, the unpredictable and predictable fear-relevant stimuli led to opposing temporal distortions. These results demonstrated that emotions modulate interval perception during different time processing stages.

Eliciting User Requirements Using Appreciative Inquiry

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Gonzales, Carol Kernitzki

2010-01-01

Many software development projects fail because they do not meet the needs of users, are over-budget, and abandoned. To address this problem, the user requirements elicitation process was modified based on principles of Appreciative Inquiry. Appreciative Inquiry, commonly used in organizational development, aims to build organizations, processes,…

The Motivating Effect of Antecedent Stimuli on the Web Shop: A Conjoint Analysis of the Impact of Antecedent Stimuli at the Point of Online Purchase

Science.gov (United States)

Fagerstrom, Asle

2010-01-01

This article introduces the concept of motivating operation (MO) to the field of online consumer research. A conjoint analysis was conducted to assess the motivating impact of antecedent stimuli on online purchasing. Stimuli tested were in-stock status, price, other customers' reviews, order confirmation procedures, and donation to charity. The…

Reinforcement Learning in Repeated Portfolio Decisions

OpenAIRE

Diao, Linan; Rieskamp, Jörg

2011-01-01

How do people make investment decisions when they receive outcome feedback? We examined how well the standard mean-variance model and two reinforcement models predict people's portfolio decisions. The basic reinforcement model predicts a learning process that relies solely on the portfolio's overall return, whereas the proposed extended reinforcement model also takes the risk and covariance of the investments into account. The experimental results illustrate that people reacted sensitively to...

State-of-the-Art Prescriptive Criteria Weight Elicitation

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Mona Riabacke

2012-01-01

Full Text Available Comparatively few of the vast amounts of decision analytical methods suggested have been widely spread in actual practice. Some approaches have nevertheless been more successful in this respect than others. Quantitative decision making has moved from the study of decision theory founded on a single criterion towards decision support for more realistic decision-making situations with multiple, often conflicting, criteria. Furthermore, the identified gap between normative and descriptive theories seems to suggest a shift to more prescriptive approaches. However, when decision analysis applications are used to aid prescriptive decision-making processes, additional demands are put on these applications to adapt to the users and the context. In particular, the issue of weight elicitation is crucial. There are several techniques for deriving criteria weights from preference statements. This is a cognitively demanding task, subject to different biases, and the elicited values can be heavily dependent on the method of assessment. There have been a number of methods suggested for assessing criteria weights, but these methods have properties which impact their applicability in practice. This paper provides a survey of state-of-the-art weight elicitation methods in a prescriptive setting.

Sexual desire, not hypersexuality, is related to neurophysiological responses elicited by sexual images

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Vaughn R. Steele

2013-07-01

Full Text Available Background: Modulation of sexual desires is, in some cases, necessary to avoid inappropriate or illegal sexual behavior (downregulation of sexual desire or to engage with a romantic partner (upregulation of sexual desire. Some have suggested that those who have difficulty downregulating their sexual desires be diagnosed as having a sexual “addiction”. This diagnosis is thought to be associated with sexual urges that feel out of control, high-frequency sexual behavior, consequences due to those behaviors, and poor ability to reduce those behaviors. However, such symptoms also may be better understood as a non-pathological variation of high sexual desire. Hypersexuals are thought to be relatively sexual reward sensitized, but also to have high exposure to visual sexual stimuli. Thus, the direction of neural responsivity to sexual stimuli expected was unclear. If these individuals exhibit habituation, their P300 amplitude to sexual stimuli should be diminished; if they merely have high sexual desire, their P300 amplitude to sexual stimuli should be increased. Neural responsivity to sexual stimuli in a sample of hypersexuals could differentiate these two competing explanations of symptoms. Methods: Fifty-two (13 female individuals who self-identified as having problems regulating their viewing of visual sexual stimuli viewed emotional (pleasant sexual, pleasant-non-sexual, neutral, and unpleasant photographs while electroencephalography was collected. Results: Larger P300 amplitude differences to pleasant sexual stimuli, relative to neutral stimuli, was negatively related to measures of sexual desire, but not related to measures of hypersexuality. Conclusion: Implications for understanding hypersexuality as high desire, rather than disordered, are discussed.

Dynamism of Stimuli-Responsive Nanohybrids: Environmental Implications

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Jaime Plazas-Tuttle

2015-06-01

Full Text Available Nanomaterial science and design have shifted from generating single passive nanoparticles to more complex and adaptive multi-component nanohybrids. These adaptive nanohybrids (ANHs are designed to simultaneously perform multiple functions, while actively responding to the surrounding environment. ANHs are engineered for use as drug delivery carriers, in tissue-engineered templates and scaffolds, adaptive clothing, smart surface coatings, electrical switches and in platforms for diversified functional applications. Such ANHs are composed of carbonaceous, metallic or polymeric materials with stimuli-responsive soft-layer coatings that enable them to perform such switchable functions. Since ANHs are engineered to dynamically transform under different exposure environments, evaluating their environmental behavior will likely require new approaches. Literature on polymer science has established a knowledge core on stimuli-responsive materials. However, translation of such knowledge to environmental health and safety (EHS of these ANHs has not yet been realized. It is critical to investigate and categorize the potential hazards of ANHs, because exposure in an unintended or shifting environment could present uncertainty in EHS. This article presents a perspective on EHS evaluation of ANHs, proposes a principle to facilitate their identification for environmental evaluation, outlines a stimuli-based classification for ANHs and discusses emerging properties and dynamic aspects for systematic EHS evaluation.

Attention bias towards personally relevant stimuli: the individual emotional Stroop task.

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Wingenfeld, Katja; Bullig, Renate; Mensebach, Christoph; Hartje, Wolfgang; Driessen, Martin; Beblo, Thomas

2006-12-01

The emotional Stroop task is a widely used method for investigating attentional bias towards stimuli due to mood or affect. In general, standardized stimuli are used, which might not be appropriate when investigating individual contextual frameworks. It was investigated whether words chosen to be related to individuals' personal life events would produce more pronounced Stroop interference (as an indicator of attentional bias) than stimuli without any personal relevance. Twenty-six nonclinical subjects, 20 female and 6 male, participated in the study. Mean age was 36.1 yr. (SD = 18.1). All were recruited by means of local advertising. Stimulus material consisted of four word types: personal words related to negative life events with and without current personal relevance, and negative and neutral words without any personal relevance. Words were presented in three blocks. Analysis of variance showed main effects for word type and blocks, with slower reactions in the personally relevant conditions than in the negative, or neutral conditions, and in response to the first blocks as opposed to the last. These findings indicate that regardless of the word valence, personally relevant stimuli evoke more pronounced Stroop interference than do stimuli without personal relevance.

Gaze-independent ERP-BCIs: augmenting performance through location-congruent bimodal stimuli

Science.gov (United States)

Thurlings, Marieke E.; Brouwer, Anne-Marie; Van Erp, Jan B. F.; Werkhoven, Peter

2014-01-01

Gaze-independent event-related potential (ERP) based brain-computer interfaces (BCIs) yield relatively low BCI performance and traditionally employ unimodal stimuli. Bimodal ERP-BCIs may increase BCI performance due to multisensory integration or summation in the brain. An additional advantage of bimodal BCIs may be that the user can choose which modality or modalities to attend to. We studied bimodal, visual-tactile, gaze-independent BCIs and investigated whether or not ERP components’ tAUCs and subsequent classification accuracies are increased for (1) bimodal vs. unimodal stimuli; (2) location-congruent vs. location-incongruent bimodal stimuli; and (3) attending to both modalities vs. to either one modality. We observed an enhanced bimodal (compared to unimodal) P300 tAUC, which appeared to be positively affected by location-congruency (p = 0.056) and resulted in higher classification accuracies. Attending either to one or to both modalities of the bimodal location-congruent stimuli resulted in differences between ERP components, but not in classification performance. We conclude that location-congruent bimodal stimuli improve ERP-BCIs, and offer the user the possibility to switch the attended modality without losing performance. PMID:25249947

Rational and Mechanistic Perspectives on Reinforcement Learning

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Chater, Nick

2009-01-01

This special issue describes important recent developments in applying reinforcement learning models to capture neural and cognitive function. But reinforcement learning, as a theoretical framework, can apply at two very different levels of description: "mechanistic" and "rational." Reinforcement learning is often viewed in mechanistic terms--as…

Conditioned Reinforcement Value and Resistance to Change

Science.gov (United States)

Shahan, Timothy A.; Podlesnik, Christopher A.

2008-01-01

Three experiments examined the effects of conditioned reinforcement value and primary reinforcement rate on resistance to change using a multiple schedule of observing-response procedures with pigeons. In the absence of observing responses in both components, unsignaled periods of variable-interval (VI) schedule food reinforcement alternated with…

Effect of stimuli, transducers and gender on acoustic change complex

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Hemanth N. Shetty

2012-08-01

Full Text Available The objective of this study was to investigate the effect of stimuli, transducers and gender on the latency and amplitude of acoustic change complex (ACC. ACC is a multiple overlapping P1-N1-P2 complex reflecting acoustic changes across the entire stimulus. Fifteen males and 15 females, in the age range of 18 to 25 (mean=21.67 years, having normal hearing participated in the study. The ACC was recorded using the vertical montage. The naturally produced stimuli /sa/ and /si/ were presented through the insert earphone/loud speaker to record the ACC. The ACC obtained from different stimuli presented through different transducers from male/female participants were analyzed using mixed analysis of variance. Dependent t-test and independent t-test were performed when indicated. There was a significant difference in latency of 2N1 at the transition, with latency for /sa/ being earlier; but not at the onset portions of ACC. There was no significant difference in amplitude of ACC between the stimuli. Among the transducers, there was no significant difference in latency and amplitude of ACC, for both /sa/ and /si/ stimuli. Female participants showed earlier latency for 2N1 and larger amplitude of N1 and 2P2 than male participants, which was significant. ACC provides important insight in detecting the subtle spectral changes in each stimulus. Among the transducers, no difference in ACC was noted as the spectra of stimuli delivered were within the frequency response of the transducers. The earlier 2N1 latency and larger N1 and 2P2 amplitudes noticed in female participants could be due to smaller head circumference. The findings of this study will be useful in determining the capacity of the auditory pathway in detecting subtle spectral changes in the stimulus at the level of the auditory cortex.

Product perception from sensory stimuli: the case of vacuum cleaner.

Science.gov (United States)

Almeida e Silva, Caio Márcio; Okimoto, Maria Lúciar R L; Tanure, Raffaela Leane Zenni

2012-01-01

This paper discusses the importance of consideration of different sensory stimuli in the perception of the product. So we conducted an experiment that examined whether there is a difference between the perception of sensory stimuli from artificially isolated. The result is an analysis of the different sensory modalities, relating them to product an between them.

Glass FRP reinforcement in rehabilitation of concrete marine infrastructure

International Nuclear Information System (INIS)

Newhook, John P.

2006-01-01

Fiber reinforced polymer (FRP) reinforcements for concrete structures are gaining wide acceptance as a suitable alternative to steel reinforcements. The primary advantage is that they do not suffer corrosion and hence they promise to be more durable in environments where steel reinforced concrete has a limited life span. Concrete wharves and jetties are examples of structures subjected to such harsh environments and represent the general class of marine infrastructure in which glass FRP (GFRP) reinforcement should be used for improved durability and service life. General design considerations which make glass FRP suitable for use in marine concrete rehabilitation projects are discussed. A case study of recent wharf rehabilitation project in Canada is used to reinforce these considerations. The structure consisted of a GFRP reinforced concrete deck panel and steel - GFRP hybrid reinforced concrete pile cap. A design methodology is developed for the hybrid reinforcement design and verified through testing. The results of a field monitoring program are used to establish the satisfactory field performance of the GFRP reinforcement. The design concepts presented in the paper are applicable to many concrete marine components and other structures where steel reinforcement corrosion is a problem. (author)

Deep brain stimulation of the nucleus accumbens shell attenuates cue-induced reinstatement of both cocaine and sucrose seeking in rats.

Science.gov (United States)

Guercio, Leonardo A; Schmidt, Heath D; Pierce, R Christopher

2015-03-15

Stimuli previously associated with drug taking can become triggers that can elicit craving and lead to relapse of drug-seeking behavior. Here, we examined the influence of deep brain stimulation (DBS) in the nucleus accumbens shell on cue-induced reinstatement of cocaine seeking, an animal model of relapse. Rats were allowed to self-administer cocaine (0.254 mg, i.v.) for 2 h daily for 21 days, with each infusion of cocaine being paired with a cue light. After 21 days of self-administration, cocaine-taking behavior was extinguished by replacing cocaine with saline in the absence of the cue light. Next, during the reinstatement phase, DBS was administered bilaterally into the nucleus accumbens shell through bipolar stainless steel electrodes immediately prior to re-exposure to cues previously associated with cocaine reinforcement. DBS continued throughout the 2 h reinstatement session. Parallel studies examined the influence of accumbens shell DBS on reinstatement induced by cues previously associated with sucrose reinforcement. Results indicated that DBS of the nucleus accumbens shell significantly attenuated cue-induced reinstatement of cocaine and sucrose seeking. Together, these results indicate that DBS of the accumbens shell disrupts cue-induced reinstatement associated with both a drug and a natural reinforcer. Copyright © 2014 Elsevier B.V. All rights reserved.