Larkin, Paul; Mesagno, Christopher; Berry, Jason; Spittle, Michael; Harvey, Jack
Decision-making is a central component of the in-game performance of Australian football umpires; however, current umpire training focuses largely on physiological development with decision-making skills development conducted via explicit lecture-style meetings with limited practice devoted to making actual decisions. Therefore, this study investigated the efficacy of a video-based training programme, aimed to provide a greater amount of contextualised visual experiences without explicit instruction, to improve decision-making skills of umpires. Australian football umpires (n = 52) were recruited from metropolitan and regional Division 1 competitions. Participants were randomly assigned to an intervention or control group and classified according to previous umpire game experience (i.e., experienced; less experienced). The intervention group completed a 12-week video-based decision-making training programme, with decision-making performance assessed at pre-training, and 1-week retention and 3-week retention periods. The control group did not complete any video-based training. Results indicated a significant Group (intervention; Control) × Test interaction (F(1, 100) = 3.98; P = 0.02, partial ῆ(2) = 0.074), with follow-up pairwise comparisons indicating significant within-group differences over time for the intervention group. In addition, decision-making performance of the less experienced umpires in the intervention group significantly improved (F(2, 40) = 5.03, P = 0.01, partial ῆ(2) = 0.201). Thus, video-based training programmes may be a viable adjunct to current training programmes to hasten decision-making development, especially for less experienced umpires.
Klusemann, Markus J; Pyne, David B; Fay, Tristan S; Drinkwater, Eric J
Junior basketball athletes require a well-designed resistance training program to improve their physical development. Lack of expert supervision and resistance training in junior development pathways may be overcome by implementing an online video-based program. The aim of this study was to compare the magnitude of improvement (change) in physical performance and strength and functional movement patterns of junior basketball athletes using either a fully supervised or an online video-based resistance training program. Thirty-eight junior basketball athletes (males, n = 17; age, 14 ± 1 year; height, 1.79 ± 0.10 m; mass, 67 ± 12 kg; females, n = 21; age, 15 ± 1 year; height, 1.70 ± 0.07 m; mass, 62 ± 8 kg) were randomly assigned into a supervised resistance training group (SG, n = 13), video training group (VG, n = 13) or control group (CG, n = 12) and participated in a 6-week controlled experimental trial. Pre- and posttesting included measures of physical performance (20-m sprint, step-in vertical jump, agility, sit and reach, line drill, and Yo-Yo intermittent recovery level 1), strength (15 s push-up and pull-up), and functional movement screening (FMS). Both SG and VG achieved 3-5% ± 2-4% (mean ± 90% confidence limits) greater improvements in several physical performance measures (vertical jump height, 20-m sprint time, and Yo-Yo endurance performance) and a 28 ± 21% greater improvement in push-up strength compared with the CG. The SG attained substantially larger gains in FMS scores over both the VG (12 ± 10%) and CG (13 ± 8%). Video-based training appears to be a viable option to improve physical performance and strength in junior basketball athletes. Qualified supervision is recommended to improve functional movement patterns in junior athletes.
Conkey, Curtis A; Bowers, Clint; Cannon-Bowers, Janis; Sanchez, Alicia
Multimedia training methods have traditionally relied heavily on video-based technologies, and significant research has shown these to be very effective training tools. However, production of video is time and resource intensive. Machinima technologies are based on videogaming technology. Machinima technology allows videogame technology to be manipulated into unique scenarios based on entertainment or training and practice applications. Machinima is the converting of these unique scenarios into video vignettes that tell a story. These vignettes can be interconnected with branching points in much the same way that education videos are interconnected as vignettes between decision points. This study addressed the effectiveness of machinima-based soft-skills education using avatar actors versus the traditional video teaching application using human actors in the training of frontline healthcare workers. This research also investigated the difference between presence reactions when using avatar actor-produced video vignettes as compared with human actor-produced video vignettes. Results indicated that the difference in training and/or practice effectiveness is statistically insignificant for presence, interactivity, quality, and the skill of assertiveness. The skill of active listening presented a mixed result indicating the need for careful attention to detail in situations where body language and facial expressions are critical to communication. This study demonstrates that a significant opportunity exists for the exploitation of avatar actors in video-based instruction.
Ricciotti, Hope A; Freret, Taylor S; Aluko, Ashley; McKeon, Bri Anne; Haviland, Miriam J; Newman, Lori R
To pilot a short video-based resident-as-teacher training toolkit and assess its effect on resident teaching skills in clinical settings. A video-based resident-as-teacher training toolkit was previously developed by educational experts at Beth Israel Deaconess Medical Center, Harvard Medical School. Residents were recruited from two academic hospitals, watched two videos from the toolkit ("Clinical Teaching Skills" and "Effective Clinical Supervision"), and completed an accompanying self-study guide. A novel assessment instrument for evaluating the effect of the toolkit on teaching was created through a modified Delphi process. Before and after the intervention, residents were observed leading a clinical teaching encounter and scored using the 15-item assessment instrument. The primary outcome of interest was the change in number of skills exhibited, which was assessed using the Wilcoxon signed-rank test. Twenty-eight residents from two academic hospitals were enrolled, and 20 (71%) completed all phases of the study. More than one third of residents who volunteered to participate reported no prior formal teacher training. After completing two training modules, residents demonstrated a significant increase in the median number of teaching skills exhibited in a clinical teaching encounter, from 7.5 (interquartile range 6.5-9.5) to 10.0 (interquartile range 9.0-11.5; Passessed, there were significant improvements in asking for the learner's perspective (P=.01), providing feedback (P=.005), and encouraging questions (P=.046). Using a resident-as-teacher video-based toolkit was associated with improvements in teaching skills in residents from multiple specialties.
Full Text Available Background: Within nursing, Emotional intelligence (EI means the ability of nurses or nursing students to understand not only their own feelings and reactions, but also, and more importantly, the feelings and reactions of the patients in their care. EI plays an important part in forming successful human relationships as a part of emotional labour. Emotional labour is important in establishing therapeutic nurse–patient relationships but carries the risk of ‘burnout’ if prolonged or intense. Objective/Purpose: The assessment of students' views and perceptions of video-based training as an opportunity to develop emotional intelligence. Material and methods: Data about the video-based training in relation to EI were collected, after the completion of the reflection assignments, using semi-structured interviews and reflective sheets (ALACT model /acronym of the basic phases and steps/ - Action, Looking back on the action, Awareness of essential aspects, Creating alternative methods of action, Trial. The study included 46 students in total (post-graduate student Intensive care nurses in two sequential academic years (2012/13 n = 15 and 2013/14 n = 31. Results: The results showed that students in both cohorts considered video as an effective tool for carrying out self-evaluations and development of EI. The usefulness of video and peer-feedback for other reflection processes differed in students' view. Most students (80% appreciated the opportunity of viewing some unusual situations from clinical practice and appropriate ways of communicating. Some students (17% stated that they needed more time for similar teaching activities. Conclusion: 80% of all the students considered video-based training generally useful for all the reflection processes and improvement of EI; however they also indicated some limitations (i.e. time consuming teaching method. The study demonstrated that student-centric pedagogies and reflective activities on student learning
Zhang, Qiang; Li, Baoxin
A proper temporal model is essential to analysis tasks involving sequential data. In computer-assisted surgical training, which is the focus of this study, obtaining accurate temporal models is a key step towards automated skill-rating. Conventional learning approaches can have only limited success in this domain due to insufficient amount of data with accurate labels. We propose a novel formulation termed Relative Hidden Markov Model and develop algorithms for obtaining a solution under this formulation. The method requires only relative ranking between input pairs, which are readily available from training sessions in the target application, hence alleviating the requirement on data labeling. The proposed algorithm learns a model from the training data so that the attribute under consideration is linked to the likelihood of the input, hence supporting comparing new sequences. For evaluation, synthetic data are first used to assess the performance of the approach, and then we experiment with real videos from a widely-adopted surgical training platform. Experimental results suggest that the proposed approach provides a promising solution to video-based motion skill evaluation. To further illustrate the potential of generalizing the method to other applications of temporal analysis, we also report experiments on using our model on speech-based emotion recognition.
Milazzo, Nicolas; Farrow, Damian; Fournier, Jean F
This study investigated the effect of a 12-session, implicit perceptual-motor training program on decision-making skills and visual search behavior of highly skilled junior female karate fighters (M age = 15.7 years, SD = 1.2). Eighteen participants were required to make (physical or verbal) reaction decisions to various attacks within different fighting scenarios. Fighters' performance and eye movements were assessed before and after the intervention, and during acquisition through the use of video-based and on-mat decision-making tests. The video-based test revealed that following training, only the implicit perceptual-motor group (n = 6) improved their decision-making accuracy significantly compared to a matched motor training (placebo, n = 6) group and a control group (n = 6). Further, the implicit training group significantly changed their visual search behavior by focusing on fewer locations for longer durations. In addition, the session-by-session analysis showed no significant improvement in decision accuracy between training session 1 and all the other sessions, except the last one. Coaches should devote more practice time to implicit learning approaches during perceptual-motor training program to achieve significant decision-making improvements and more efficient visual search strategy with elite athletes. © The Author(s) 2016.
De Niear, Matthew A; Gupta, Pranjal B; Baum, Sarah H; Wallace, Mark T
The temporal relationship between auditory and visual cues is a fundamental feature in the determination of whether these signals will be integrated. The window of perceived simultaneity (TBW) is a construct that describes the epoch of time during which asynchronous auditory and visual stimuli are likely to be perceptually bound. Recently, a number of studies have demonstrated the capacity for perceptual training to enhance temporal acuity for audiovisual stimuli (i.e., narrow the TBW). These studies, however, have only examined multisensory perceptual learning that develops in response to feedback that is provided when making judgments on simple, low-level audiovisual stimuli (i.e., flashes and beeps). Here we sought to determine if perceptual training was capable of altering temporal acuity for audiovisual speech. Furthermore, we also explored whether perceptual training with simple or complex audiovisual stimuli generalized across levels of stimulus complexity. Using a simultaneity judgment (SJ) task, we measured individuals' temporal acuity (as estimated by the TBW) prior to, immediately following, and one week after four consecutive days of perceptual training. We report that temporal acuity for audiovisual speech stimuli is enhanced following perceptual training using speech stimuli. Additionally, we find that changes in temporal acuity following perceptual training do not generalize across the levels of stimulus complexity in this study. Overall, the results suggest that perceptual training is capable of enhancing temporal acuity for audiovisual speech in adults, and that the dynamics of the changes in temporal acuity following perceptual training differ between simple audiovisual stimuli and more complex audiovisual speech stimuli. Copyright © 2017. Published by Elsevier Inc.
Ryan A Stevenson
Full Text Available The process of integrating information across sensory modalities is highly dependent upon the temporal coincidence of the inputs. Audiovisual information is integrated within a range of temporal offsets, known as the temporal binding window (TBW, which varies between individuals. Three particular findings relating to TBW have led us to a novel approach to address sensory integration impairments in children with autism. The first is that autistic children have an atypically wide TBW, as measured through manipulations of audiovisual illusions. Second, an individual's TBW is related to their ability to perceptually fuse audiovisual inputs, particularly as seen in the McGurk effect; the narrower the right TBW, the stronger the McGurk effect. The third finding is that the TBW is plastic. Through perceptual feedback training, our lab showed that individuals' right TBW can be narrowed. These three findings, which we will present, lead to a study of perceptual feedback training in autistic children, who may have the ability to narrow their TBW, with a possible positive impact on their ability to integrate multisensory information, specifically speech. We will conclude with the presentation of behavioral and electrophysiological data illustrating an atypical relationship between the TBW and perceptual fusion in ASD.
Cohen, Yamit; Daikhin, Luba; Ahissar, Merav
What do we learn when we practice a simple perceptual task? Many studies have suggested that we learn to refine or better select the sensory representations of the task-relevant dimension. Here we show that learning is specific to the trained structural regularities. Specifically, when this structure is modified after training with a fixed temporal structure, performance regresses to pretraining levels, even when the trained stimuli and task are retained. This specificity raises key questions as to the importance of low-level sensory modifications in the learning process. We trained two groups of participants on a two-tone frequency discrimination task for several days. In one group, a fixed reference tone was consistently presented in the first interval (the second tone was higher or lower), and in the other group the same reference tone was consistently presented in the second interval. When following training, these temporal protocols were switched between groups, performance of both groups regressed to pretraining levels, and further training was needed to attain postlearning performance. ERP measures, taken before and after training, indicated that participants implicitly learned the temporal regularity of the protocol and formed an attentional template that matched the trained structure of information. These results are consistent with Reverse Hierarchy Theory, which posits that even the learning of simple perceptual tasks progresses in a top-down manner, hence can benefit from temporal regularities at the trial level, albeit at the potential cost that learning may be specific to these regularities.
David P Broadbent
Full Text Available Anticipation of opponent actions, through the use of advanced (i.e., pre-event kinematic information, can be trained using video-based temporal occlusion. Typically, this involves isolated opponent skills/shots presented as trials in a random order. However, two different areas of research concerning representative task design and contextual (non-kinematic information, suggest this structure of practice restricts expert performance. The aim of this study was to examine the effect of a sequential structure of practice during video-based training of anticipatory behavior in tennis, as well as the transfer of these skills to the performance environment.In a pre-practice-retention-transfer design, participants viewed life-sized video of tennis rallies across practice in either a sequential order (sequential group, in which participants were exposed to opponent skills/shots in the order they occur in the sport, or a non-sequential (non-sequential group random order.In the video-based retention test, the sequential group was significantly more accurate in their anticipatory judgments when the retention condition replicated the sequential structure compared to the non-sequential group. In the non-sequential retention condition, the non-sequential group was more accurate than the sequential group. In the field-based transfer test, overall decision time was significantly faster in the sequential group compared to the non-sequential group.Findings highlight the benefits of a sequential structure of practice for the transfer of anticipatory behavior in tennis. We discuss the role of contextual information, and the importance of representative task design, for the testing and training of perceptual-cognitive skills in sport.
Lebrecht, Sophie; Pierce, Lara J; Tarr, Michael J; Tanaka, James W
Implicit racial bias denotes socio-cognitive attitudes towards other-race groups that are exempt from conscious awareness. In parallel, other-race faces are more difficult to differentiate relative to own-race faces--the "Other-Race Effect." To examine the relationship between these two biases, we trained Caucasian subjects to better individuate other-race faces and measured implicit racial bias for those faces both before and after training. Two groups of Caucasian subjects were exposed equally to the same African American faces in a training protocol run over 5 sessions. In the individuation condition, subjects learned to discriminate between African American faces. In the categorization condition, subjects learned to categorize faces as African American or not. For both conditions, both pre- and post-training we measured the Other-Race Effect using old-new recognition and implicit racial biases using a novel implicit social measure--the "Affective Lexical Priming Score" (ALPS). Subjects in the individuation condition, but not in the categorization condition, showed improved discrimination of African American faces with training. Concomitantly, subjects in the individuation condition, but not the categorization condition, showed a reduction in their ALPS. Critically, for the individuation condition only, the degree to which an individual subject's ALPS decreased was significantly correlated with the degree of improvement that subject showed in their ability to differentiate African American faces. Our results establish a causal link between the Other-Race Effect and implicit racial bias. We demonstrate that training that ameliorates the perceptual Other-Race Effect also reduces socio-cognitive implicit racial bias. These findings suggest that implicit racial biases are multifaceted, and include malleable perceptual skills that can be modified with relatively little training.
Full Text Available BACKGROUND: Implicit racial bias denotes socio-cognitive attitudes towards other-race groups that are exempt from conscious awareness. In parallel, other-race faces are more difficult to differentiate relative to own-race faces--the "Other-Race Effect." To examine the relationship between these two biases, we trained Caucasian subjects to better individuate other-race faces and measured implicit racial bias for those faces both before and after training. METHODOLOGY/PRINCIPAL FINDINGS: Two groups of Caucasian subjects were exposed equally to the same African American faces in a training protocol run over 5 sessions. In the individuation condition, subjects learned to discriminate between African American faces. In the categorization condition, subjects learned to categorize faces as African American or not. For both conditions, both pre- and post-training we measured the Other-Race Effect using old-new recognition and implicit racial biases using a novel implicit social measure--the "Affective Lexical Priming Score" (ALPS. Subjects in the individuation condition, but not in the categorization condition, showed improved discrimination of African American faces with training. Concomitantly, subjects in the individuation condition, but not the categorization condition, showed a reduction in their ALPS. Critically, for the individuation condition only, the degree to which an individual subject's ALPS decreased was significantly correlated with the degree of improvement that subject showed in their ability to differentiate African American faces. CONCLUSIONS/SIGNIFICANCE: Our results establish a causal link between the Other-Race Effect and implicit racial bias. We demonstrate that training that ameliorates the perceptual Other-Race Effect also reduces socio-cognitive implicit racial bias. These findings suggest that implicit racial biases are multifaceted, and include malleable perceptual skills that can be modified with relatively little training.
Norton, Daniel J.; McBain, Ryan K.; Ongur, Dost; Chen, Yue
Schizophrenia patients exhibit perceptual and cognitive deficits, including in visual motion processing. Given that cognitive systems depend upon perceptual inputs, improving patients' perceptual abilities may be an effective means of cognitive intervention. In healthy people, motion perception can be enhanced through perceptual learning, but it…
Jimenez-Reyes, P; Pareja-Blanco, F; Cuadrado-Peñafiel, V; Morcillo, J A; Párraga, J A; González-Badillo, J J
This study aimed to analyze perceptual, metabolic and mechanical responses to sprint training sessions. 9 male high-level sprinters performed 40 m running sprints up to a loss of 3% in speed, with 4 min rests between sets. Perceptual (rating of perceived exertion, RPE), mechanical (speed and countermovement jump height loss) and metabolic (blood lactate and ammonia) parameters were measured pre-exercise and after each sprint was performed. Relationships between the variables were calculated with a 90% confidence interval. Jump height loss showed almost perfect relationships with both blood lactate (r=0.96 (0.95 to 0.97)) and ammonia (r=0.95 (0.94 to 0.95)), whereas speed loss, number of sprints performed and RPE values showed large-very large relationships with blood lactate and ammonia. Furthermore, an almost perfect curvilinear relationship was observed between lactate and ammonia concentrations (R(2)=0.96 (0.95 to 0.97)). These results suggest that countermovement jump (CMJ) height can be used to quantify the fatigue induced during a typical sprint training session, and may prove a useful tool to facilitate individualized load monitoring. The results indicate that the CMJ is a better monitor of metabolic fatigue than traditional measures. © Georg Thieme Verlag KG Stuttgart · New York.
Chen, Yi-Nan; Lin, Chin-Kai; Wei, Ta-Sen; Liu, Chi-Hsin; Wuang, Yee-Pay
This study compared the effectiveness of three approaches to improving visual perception among preschool children 4-6 years old with developmental delays: multimedia visual perceptual group training, multimedia visual perceptual individual training, and paper visual perceptual group training. A control group received no special training. This study employed a pretest-posttest control group of true experimental design. A total of 64 children 4-6 years old with developmental delays were randomized into four groups: (1) multimedia visual perceptual group training (15 subjects); (2) multimedia visual perceptual individual training group (15 subjects); paper visual perceptual group training (19 subjects); and (4) a control group (15 subjects) with no visual perceptual training. Forty minute training sessions were conducted once a week for 14 weeks. The Test of Visual Perception Skills, third edition, was used to evaluate the effectiveness of the intervention. Paired-samples t-test showed significant differences pre- and post-test among the three groups, but no significant difference was found between the pre-test and post-test scores among the control group. ANOVA results showed significant differences in improvement levels among the four study groups. Scheffe post hoc test results showed significant differences between: group 1 and group 2; group 1 and group 3; group 1 and the control group; and group 2 and the control group. No significant differences were reported between group 2 and group 3, and group 3 and the control group. The results showed all three therapeutic programs produced significant differences between pretest and posttest scores. The training effect on the multimedia visual perceptual group program and the individual program was greater than the developmental effect Both the multimedia visual perceptual group training program and the multimedia visual perceptual individual training program produced significant effects on visual perception. The
Lametti, Daniel R; Krol, Sonia A; Shiller, Douglas M; Ostry, David J
The perception of speech is notably malleable in adults, yet alterations in perception seem to have little impact on speech production. However, we hypothesized that speech perceptual training might immediately influence speech motor learning. To test this, we paired a speech perceptual-training task with a speech motor-learning task. Subjects performed a series of perceptual tests designed to measure and then manipulate the perceptual distinction between the words head and had. Subjects then produced head with the sound of the vowel altered in real time so that they heard themselves through headphones producing a word that sounded more like had. In support of our hypothesis, the amount of motor learning in response to the voice alterations depended on the perceptual boundary acquired through perceptual training. The studies show that plasticity in adults' speech perception can have immediate consequences for speech production in the context of speech learning. © The Author(s) 2014.
Caserta, Ryan J; Young, Jessica; Janelle, Christopher M
The purpose of the study was to determine whether multidimensional perceptual-cognitive skills training, including situational awareness, anticipation, and decision making, improves on-court performance in older adults when compared with a physical training program, including stroke and footwork development. Senior tennis players (N = 27) were randomly assigned to one of three groups: perceptual-cognitive skills training, technique-footwork training, or no training. Results indicated that participants receiving perceptual-cognitive skills training had significantly faster response speeds, higher percentage of accurate responses, and higher percentage of performance decision making in posttest match situations. Findings provide clear evidence that perceptual-cognitive skills can be trained in aged individuals. Implications and suggestions for future research are offered.
Magnor, Marcus A
Driven by consumer-market applications that enjoy steadily increasing economic importance, graphics hardware and rendering algorithms are a central focus of computer graphics research. Video-based rendering is an approach that aims to overcome the current bottleneck in the time-consuming modeling process and has applications in areas such as computer games, special effects, and interactive TV. This book offers an in-depth introduction to video-based rendering, a rapidly developing new interdisciplinary topic employing techniques from computer graphics, computer vision, and telecommunication en
Benoit, Charles-Etienne; Dalla Bella, Simone; Farrugia, Nicolas; Obrig, Hellmuth; Mainka, Stefan; Kotz, Sonja A
It is well established that auditory cueing improves gait in patients with idiopathic Parkinson's disease (IPD). Disease-related reductions in speed and step length can be improved by providing rhythmical auditory cues via a metronome or music. However, effects on cognitive aspects of motor control have yet to be thoroughly investigated. If synchronization of movement to an auditory cue relies on a supramodal timing system involved in perceptual, motor, and sensorimotor integration, auditory cueing can be expected to affect both motor and perceptual timing. Here, we tested this hypothesis by assessing perceptual and motor timing in 15 IPD patients before and after a 4-week music training program with rhythmic auditory cueing. Long-term effects were assessed 1 month after the end of the training. Perceptual and motor timing was evaluated with a battery for the assessment of auditory sensorimotor and timing abilities and compared to that of age-, gender-, and education-matched healthy controls. Prior to training, IPD patients exhibited impaired perceptual and motor timing. Training improved patients' performance in tasks requiring synchronization with isochronous sequences, and enhanced their ability to adapt to durational changes in a sequence in hand tapping tasks. Benefits of cueing extended to time perception (duration discrimination and detection of misaligned beats in musical excerpts). The current results demonstrate that auditory cueing leads to benefits beyond gait and support the idea that coupling gait to rhythmic auditory cues in IPD patients relies on a neuronal network engaged in both perceptual and motor timing.
Iwarsson, Jenny; Petersen, Niels Reinholt
Objectives/Hypothesis: This study investigates the effect of consensus training of listeners on intrarater and interrater reliability and agreement of perceptual voice analysis. The use of such training, including a reference voice sample, could be assumed to make the internal standards held...... in memory common and more robust, which is of great importance to reduce the variability of auditory perceptual ratings. Study Design: A prospective design with testing before and after training. Methods: Thirteen students of audiologopedics served as listening subjects. The ratings were made using...... a multidimensional protocol with four-point equal-appearing interval scales. The stimuli consisted of text reading by authentic dysphonic patients. The consensus training for each perceptual voice parameter included (1) definition, (2) underlying physiology, (3) presentation of carefully selected sound examples...
Martín-Hernández, Juan; Ruiz-Aguado, Jorge; Herrero, Azael Juan
.01). No between-group differences were found at any time point. In summary, BFRT induces a high perceptual response to training. However, this perceptual response is rapidly attenuated, leading to values similar to those experienced during HIT. Low load BFRT should not be limited to highly motivated individuals......The purpose of this study was to determine the adaptive response of ratings of perceived exertion (RPE) and pain over six consecutive training sessions. Thirty subjects were assigned to either a blood flow restricted training group (BFRT) or a high intensity group (HIT). BFRT group performed four...
Oudejans, R.R.D.; Pijpers, J.R.
In two experiments, we examined whether training with anxiety can prevent choking in experts performing perceptual-motor tasks. In Experiment 1, 17 expert basketball players practised free throws over a 5-week period with or without induced anxiety. Only after training with anxiety did performance
Qian, Miao K.; Quinn, Paul C.; Heyman, Gail D.; Pascalis, Olivier; Fu, Genyue; Lee, Kang
Two studies with preschool-age children examined the effectiveness of perceptual individuation training at reducing racial bias (Study 1, N = 32; Study 2, N = 56). We found that training preschool-age children to individuate other-race faces resulted in a reduction in implicit racial bias while mere exposure to other-race faces produced no such…
Abernethy, Bruce; Schorer, Jorg; Jackson, Robin C.; Hagemann, Norbert
The comparative efficacy of different perceptual training approaches for the improvement of anticipation was examined using a goalkeeping task from European handball that required the rapid prediction of shot direction. Novice participants (N = 60) were assigned equally to four different training groups and two different control groups (a placebo…
Mandarin Chinese lexical tones pose difficulties for non-native speakers whose first languages contrast or do not contrast lexical tones. In this study, both tone language and non-tone language speaking learners of Mandarin Chinese were trained for three weeks to identify the four Mandarin lexical tones. One group took the production training with both visual and audio feedback using Kay Sona Speech II software. The target tones produced by native Mandarin speakers were played back through a pair of headphones and the pitch contours of the target tones were displayed on the computer screen on the top window to be compared with the trainees productions which appear in real time in the bottom window. Another group of participants took the perceptual training only with four-way forced choice identification tasks with immediate feedback. The same training tokens were used in both training modes. Pretest and post test data in perception and production were collected from both groups and were compared for effectiveness of training procedures.
Lynne E Bernstein
Full Text Available Speech perception under audiovisual conditions is well known to confer benefits to perception such as increased speed and accuracy. Here, we investigated how audiovisual training might benefit or impede auditory perceptual learning speech degraded by vocoding. In Experiments 1 and 3, participants learned paired associations between vocoded spoken nonsense words and nonsense pictures in a protocol with a fixed number of trials. In Experiment 1, paired-associates (PA audiovisual (AV training of one group of participants was compared with audio-only (AO training of another group. When tested under AO conditions, the AV-trained group was significantly more accurate than the AO-trained group. In addition, pre- and post-training AO forced-choice consonant identification with untrained nonsense words showed that AV-trained participants had learned significantly more than AO participants. The pattern of results pointed to their having learned at the level of the auditory phonetic features of the vocoded stimuli. Experiment 2, a no-training control with testing and re-testing on the AO consonant identification, showed that the controls were as accurate as the AO-trained participants in Experiment 1 but less accurate than the AV-trained participants. In Experiment 3, PA training alternated AV and AO conditions on a list-by-list basis within participants, and training was to criterion (92% correct. PA training with AO stimuli was reliably more effective than training with AV stimuli. We explain these discrepant results in terms of the so-called "reverse hierarchy theory" of perceptual learning and in terms of the diverse multisensory and unisensory processing resources available to speech perception. We propose that early audiovisual speech integration can potentially impede auditory perceptual learning; but visual top-down access to relevant auditory features can promote auditory perceptual learning.
Bernstein, Lynne E; Auer, Edward T; Eberhardt, Silvio P; Jiang, Jintao
Speech perception under audiovisual (AV) conditions is well known to confer benefits to perception such as increased speed and accuracy. Here, we investigated how AV training might benefit or impede auditory perceptual learning of speech degraded by vocoding. In Experiments 1 and 3, participants learned paired associations between vocoded spoken nonsense words and nonsense pictures. In Experiment 1, paired-associates (PA) AV training of one group of participants was compared with audio-only (AO) training of another group. When tested under AO conditions, the AV-trained group was significantly more accurate than the AO-trained group. In addition, pre- and post-training AO forced-choice consonant identification with untrained nonsense words showed that AV-trained participants had learned significantly more than AO participants. The pattern of results pointed to their having learned at the level of the auditory phonetic features of the vocoded stimuli. Experiment 2, a no-training control with testing and re-testing on the AO consonant identification, showed that the controls were as accurate as the AO-trained participants in Experiment 1 but less accurate than the AV-trained participants. In Experiment 3, PA training alternated AV and AO conditions on a list-by-list basis within participants, and training was to criterion (92% correct). PA training with AO stimuli was reliably more effective than training with AV stimuli. We explain these discrepant results in terms of the so-called "reverse hierarchy theory" of perceptual learning and in terms of the diverse multisensory and unisensory processing resources available to speech perception. We propose that early AV speech integration can potentially impede auditory perceptual learning; but visual top-down access to relevant auditory features can promote auditory perceptual learning.
Bernstein, Lynne E.; Auer, Edward T.; Eberhardt, Silvio P.; Jiang, Jintao
Speech perception under audiovisual (AV) conditions is well known to confer benefits to perception such as increased speed and accuracy. Here, we investigated how AV training might benefit or impede auditory perceptual learning of speech degraded by vocoding. In Experiments 1 and 3, participants learned paired associations between vocoded spoken nonsense words and nonsense pictures. In Experiment 1, paired-associates (PA) AV training of one group of participants was compared with audio-only (AO) training of another group. When tested under AO conditions, the AV-trained group was significantly more accurate than the AO-trained group. In addition, pre- and post-training AO forced-choice consonant identification with untrained nonsense words showed that AV-trained participants had learned significantly more than AO participants. The pattern of results pointed to their having learned at the level of the auditory phonetic features of the vocoded stimuli. Experiment 2, a no-training control with testing and re-testing on the AO consonant identification, showed that the controls were as accurate as the AO-trained participants in Experiment 1 but less accurate than the AV-trained participants. In Experiment 3, PA training alternated AV and AO conditions on a list-by-list basis within participants, and training was to criterion (92% correct). PA training with AO stimuli was reliably more effective than training with AV stimuli. We explain these discrepant results in terms of the so-called “reverse hierarchy theory” of perceptual learning and in terms of the diverse multisensory and unisensory processing resources available to speech perception. We propose that early AV speech integration can potentially impede auditory perceptual learning; but visual top-down access to relevant auditory features can promote auditory perceptual learning. PMID:23515520
Kellman, Philip J
Recent advances in the learning sciences offer remarkable potential to improve medical education and maximize the benefits of emerging medical technologies. This article describes 2 major innovation areas in the learning sciences that apply to simulation and other aspects of medical learning: Perceptual learning (PL) and adaptive learning technologies. PL technology offers, for the first time, systematic, computer-based methods for teaching pattern recognition, structural intuition, transfer, and fluency. Synergistic with PL are new adaptive learning technologies that optimize learning for each individual, embed objective assessment, and implement mastery criteria. The author describes the Adaptive Response-Time-based Sequencing (ARTS) system, which uses each learner's accuracy and speed in interactive learning to guide spacing, sequencing, and mastery. In recent efforts, these new technologies have been applied in medical learning contexts, including adaptive learning modules for initial medical diagnosis and perceptual/adaptive learning modules (PALMs) in dermatology, histology, and radiology. Results of all these efforts indicate the remarkable potential of perceptual and adaptive learning technologies, individually and in combination, to improve learning in a variety of medical domains. Reprint & Copyright © 2013 Association of Military Surgeons of the U.S.
Silvio P Eberhardt
Full Text Available In a series of studies we have been investigating how multisensory training affects unisensory perceptual learning with speech stimuli. Previously, we reported that Aaudiovisual training with speech stimuli can promote auditory-only perceptual learning in normal-hearing adults but can impede learning in congenitally deaf adults with late-acquired cochlear implants. Here, impeder and promoter effects were sought in normal-hearing adults who participated in lipreading training. In Experiment 1, visual-only (VO training on paired associations between CVCVC nonsense word videos and nonsense pictures demonstrated that VO words could be learned to a high level of accuracy even by poor lipreaders. In Experiment 2, visual-auditory (VA training in the same paradigm but with the addition of synchronous vocoded acoustic speech impeded VO learning of the stimuli in the paired-associates paradigm. In Experiment 3, the vocoded auditory-only (AO stimuli were shown to be less informative than the VO speech. Experiment 4 combined vibrotactile speech stimuli with the visual stimuli during training. Vibrotactile stimuli were shown to promote visual perceptual learning in participants whose training scores were similar. In Experiment 5, no-training controls were used to show that training with visual speech carried over to consonant identification of untrained CVCVC stimuli but not to lipreading words in sentences. Across this and previous studies, multisensory training effects depended on the functional relationship between pathways engaged during training. Two principles are proposed to account for stimulus effects: (1 Stimuli presented to the trainee’s primary perceptual pathway will impede learning by a lower-rank pathway. (2 Stimuli presented to the trainee’s lower rank perceptual pathway will promote learning by a higher-rank pathway. The mechanisms supporting these principles are discussed in light of multisensory reverse hierarchy theory.
Eberhardt, Silvio P; Auer, Edward T; Bernstein, Lynne E
In a series of studies we have been investigating how multisensory training affects unisensory perceptual learning with speech stimuli. Previously, we reported that audiovisual (AV) training with speech stimuli can promote auditory-only (AO) perceptual learning in normal-hearing adults but can impede learning in congenitally deaf adults with late-acquired cochlear implants. Here, impeder and promoter effects were sought in normal-hearing adults who participated in lipreading training. In Experiment 1, visual-only (VO) training on paired associations between CVCVC nonsense word videos and nonsense pictures demonstrated that VO words could be learned to a high level of accuracy even by poor lipreaders. In Experiment 2, visual-auditory (VA) training in the same paradigm but with the addition of synchronous vocoded acoustic speech impeded VO learning of the stimuli in the paired-associates paradigm. In Experiment 3, the vocoded AO stimuli were shown to be less informative than the VO speech. Experiment 4 combined vibrotactile speech stimuli with the visual stimuli during training. Vibrotactile stimuli were shown to promote visual perceptual learning. In Experiment 5, no-training controls were used to show that training with visual speech carried over to consonant identification of untrained CVCVC stimuli but not to lipreading words in sentences. Across this and previous studies, multisensory training effects depended on the functional relationship between pathways engaged during training. Two principles are proposed to account for stimulus effects: (1) Stimuli presented to the trainee's primary perceptual pathway will impede learning by a lower-rank pathway. (2) Stimuli presented to the trainee's lower rank perceptual pathway will promote learning by a higher-rank pathway. The mechanisms supporting these principles are discussed in light of multisensory reverse hierarchy theory (RHT).
Anne S Berry
Full Text Available Normal aging is associated with a degradation of perceptual abilities and a decline in higher-level cognitive functions, notably working memory. To remediate age-related deficits, cognitive training programs are increasingly being developed. However, it is not yet definitively established if, and by what mechanisms, training ameliorates effects of cognitive aging. Furthermore, a major factor impeding the success of training programs is a frequent failure of training to transfer benefits to untrained abilities. Here, we offer the first evidence of direct transfer-of-benefits from perceptual discrimination training to working memory performance in older adults. Moreover, using electroencephalography to evaluate participants before and after training, we reveal neural evidence of functional plasticity in older adult brains, such that training-induced modifications in early visual processing during stimulus encoding predict working memory accuracy improvements. These findings demonstrate the strength of the perceptual discrimination training approach by offering clear psychophysical evidence of transfer-of-benefit and a neural mechanism underlying cognitive improvement.
Benoit, Charles-Etienne; Dalla Bella, Simone; Farrugia, Nicolas; Obrig, Hellmuth; Mainka, Stefan; Kotz, Sonja A.
It is well established that auditory cueing improves gait in patients with idiopathic Parkinson’s disease (IPD). Disease-related reductions in speed and step length can be improved by providing rhythmical auditory cues via a metronome or music. However, effects on cognitive aspects of motor control have yet to be thoroughly investigated. If synchronization of movement to an auditory cue relies on a supramodal timing system involved in perceptual, motor, and sensorimotor integration, auditory cueing can be expected to affect both motor and perceptual timing. Here, we tested this hypothesis by assessing perceptual and motor timing in 15 IPD patients before and after a 4-week music training program with rhythmic auditory cueing. Long-term effects were assessed 1 month after the end of the training. Perceptual and motor timing was evaluated with a battery for the assessment of auditory sensorimotor and timing abilities and compared to that of age-, gender-, and education-matched healthy controls. Prior to training, IPD patients exhibited impaired perceptual and motor timing. Training improved patients’ performance in tasks requiring synchronization with isochronous sequences, and enhanced their ability to adapt to durational changes in a sequence in hand tapping tasks. Benefits of cueing extended to time perception (duration discrimination and detection of misaligned beats in musical excerpts). The current results demonstrate that auditory cueing leads to benefits beyond gait and support the idea that coupling gait to rhythmic auditory cues in IPD patients relies on a neuronal network engaged in both perceptual and motor timing. PMID:25071522
Full Text Available It is well established that auditory cueing improves gait in patients with Idiopathic Parkinson’s Disease (IPD. Disease-related reductions in speed and step length can be improved by providing rhythmical auditory cues via a metronome or music. However, effects on cognitive aspects of motor control have yet to be thoroughly investigated. If synchronization of movement to an auditory cue relies on a supramodal timing system involved in perceptual, motor and sensorimotor integration, auditory cueing can be expected to affect both motor and perceptual timing. Here we tested this hypothesis by assessing perceptual and motor timing in 15 IPD patients before and after a four-week music training program with rhythmic auditory cueing. Long-term effects were assessed one month after the end of the training. Perceptual and motor timing was evaluated with the Battery for the Assessment of Auditory Sensorimotor and Timing Abilities (BAASTA and compared to that of age-, gender-, and education-matched healthy controls. Prior to training, IPD patients exhibited impaired perceptual and motor timing. Training improved patients’ performance in tasks requiring synchronization with isochronous sequences, and enhanced their ability to adapt to durational changes in a sequence in hand tapping tasks. Benefits of cueing extended to time perception (duration discrimination and detection of misaligned beats in musical excerpts. The current results demonstrate that auditory cueing leads to benefits beyond gait and support the idea that coupling gait to rhythmic auditory cues in IPD patients relies on a neuronal network engaged in both perceptual and motor timing.
Conrod, Beverley E.; Overbury, Olga
This study evaluated the effects of perceptual training and psychological counseling on adjustment to vision loss in 49 elderly persons (mean age 70) with low vision. Overall, both interventions improved the participants' visual functioning and beliefs about the loss of vision, and follow-up interviews revealed that these improvements were…
The present study attempted to investigate the effect of perceptual-motor training on attention in children with autism spectrum disorders. The participants (20 girls and 20 boys) were divided into experimental and control groups. They were selected from among 85 subjects after primary tests to be matched. The design of the study was…
Wang, Zhengke; Cheng-Lai, Alice; Song, Yan; Cutting, Laurie; Jiang, Yuzheng; Lin, Ou; Meng, Xiangzhi; Zhou, Xiaolin
Learning to read involves discriminating between different written forms and establishing connections with phonology and semantics. This process may be partially built upon visual perceptual learning, during which the ability to process the attributes of visual stimuli progressively improves with practice. The present study investigated to what extent Chinese children with developmental dyslexia have deficits in perceptual learning by using a texture discrimination task, in which participants were asked to discriminate the orientation of target bars. Experiment l demonstrated that, when all of the participants started with the same initial stimulus-to-mask onset asynchrony (SOA) at 300 ms, the threshold SOA, adjusted according to response accuracy for reaching 80% accuracy, did not show a decrement over 5 days of training for children with dyslexia, whereas this threshold SOA steadily decreased over the training for the control group. Experiment 2 used an adaptive procedure to determine the threshold SOA for each participant during training. Results showed that both the group of dyslexia and the control group attained perceptual learning over the sessions in 5 days, although the threshold SOAs were significantly higher for the group of dyslexia than for the control group; moreover, over individual participants, the threshold SOA negatively correlated with their performance in Chinese character recognition. These findings suggest that deficits in visual perceptual processing and learning might, in part, underpin difficulty in reading Chinese. Copyright © 2014 John Wiley & Sons, Ltd.
Tzeng, Christina Y.; Alexander, Jessica E.D.; Sidaras, Sabrina K.; Nygaard, Lynne C.
Foreign-accented speech contains multiple sources of variation that listeners learn to accommodate. Extending previous findings showing that exposure to high-variation training facilitates perceptual learning of accented speech, the current study examines to what extent the structure of training materials affects learning. During training, native adult speakers of American English transcribed sentences spoken in English by native Spanish-speaking adults. In Experiment 1, training stimuli were blocked by speaker, sentence, or randomized with respect to speaker and sentence (Variable training). At test, listeners transcribed novel English sentences produced by Spanish-accented speakers. Listeners’ transcription accuracy was highest in the Variable condition, suggesting that varying both speaker identity and sentence across training trials enabled listeners to generalize their learning to novel speakers and linguistic content. Experiment 2 assessed the extent to which ordering of training tokens by a single factor, speaker intelligibility, would facilitate speaker-independent accent learning, finding that listeners’ test performance did not reliably differ across conditions. Overall, these results suggest that the structure of training exposure, specifically trial-by-trial variation on both speaker’s voice and linguistic content, facilitates learning of the systematic properties of accented speech. The current findings suggest a crucial role of training structure in optimizing perceptual learning. Beyond characterizing the types of variation listeners encode in their representations of spoken utterances, theories of spoken language processing should incorporate the role of training structure in learning lawful variation in speech. PMID:27399829
Deveau, Jenni; Lovcik, Gary; Seitz, Aaron R
Perception is the window through which we understand all information about our environment, and therefore deficits in perception due to disease, injury, stroke or aging can have significant negative impacts on individuals' lives. Research in the field of perceptual learning has demonstrated that vision can be improved in both normally seeing and visually impaired individuals, however, a limitation of most perceptual learning approaches is their emphasis on isolating particular mechanisms. In the current study, we adopted an integrative approach where the goal is not to achieve highly specific learning but instead to achieve general improvements to vision. We combined multiple perceptual learning approaches that have individually contributed to increasing the speed, magnitude and generality of learning into a perceptual-learning based video-game. Our results demonstrate broad-based benefits of vision in a healthy adult population. Transfer from the game includes; improvements in acuity (measured with self-paced standard eye-charts), improvement along the full contrast sensitivity function, and improvements in peripheral acuity and contrast thresholds. The use of this type of this custom video game framework built up from psychophysical approaches takes advantage of the benefits found from video game training while maintaining a tight link to psychophysical designs that enable understanding of mechanisms of perceptual learning and has great potential both as a scientific tool and as therapy to help improve vision. Copyright © 2014 Elsevier B.V. All rights reserved.
Wang, Rui; Zhang, Jun-Yun; Klein, Stanley A; Levi, Dennis M; Yu, Cong
Perceptual learning, a process in which training improves visual discrimination, is often specific to the trained retinal location, and this location specificity is frequently regarded as an indication of neural plasticity in the retinotopic visual cortex. However, our previous studies have shown that "double training" enables location-specific perceptual learning, such as Vernier learning, to completely transfer to a new location where an irrelevant task is practiced. Here we show that Vernier learning can be actuated by less location-specific orientation or motion-direction learning to transfer to completely untrained retinal locations. This "piggybacking" effect occurs even if both tasks are trained at the same retinal location. However, piggybacking does not occur when the Vernier task is paired with a more location-specific contrast-discrimination task. This previously unknown complexity challenges the current understanding of perceptual learning and its specificity/transfer. Orientation and motion-direction learning, but not contrast and Vernier learning, appears to activate a global process that allows learning transfer to untrained locations. Moreover, when paired with orientation or motion-direction learning, Vernier learning may be "piggybacked" by the activated global process to transfer to other untrained retinal locations. How this task-specific global activation process is achieved is as yet unknown. © 2014 ARVO.
Martín-Hernández, Juan; Ruiz-Aguado, Jorge; Herrero, Azael J; Loenneke, Jeremy P; Aagaard, Per; Cristi-Montero, Carlos; Menéndez, Héctor; Marín, Pedro J
Martín-Hernández, J, Ruiz-Aguado, J, Herrero, AJ, Loenneke, JP, Aagaard, P, Cristi-Montero, C, Menéndez, H, and Marín, PJ. Adaptation of perceptual responses to low-load blood flow restriction training. J Strength Cond Res 31(3): 765-772, 2017-The purpose of this study was to determine the adaptive response of ratings of perceived exertion (RPE) and pain over 6 consecutive training sessions. Thirty subjects were assigned to either a blood flow restriction training (BFRT) group or a high-intensity resistance training (HIT) group. Blood flow-restricted training group performed 4 sets (30 + 15 + 15 + 15, respectively) of unilateral leg extension at an intensity of 20% one repetition maximum (1RM) while a restrictive cuff was applied to the most proximal part of the leg. The HIT group performed 3 sets of 8 repetitions with 85% 1RM. Ratings of perceived exertion and pain were assessed immediately after each exercise set along the 6 training sessions and were then averaged to obtain the overall RPE and pain per session. Statistical analyses showed significant main effects for group (p ≤ 0.05) and time (p training, comparable with that observed with HIT. However, this response becomes attenuated with continuous practice, leading to moderate values of RPE and pain. Perceptual responses may not limit the application of BFRT to highly motivated individuals.
Klostermann, André; Vater, Christian; Kredel, Ralf; Hossner, Ernst-Joachim
.... Consequently, after a preparatory study on the identification of appropriate visual cues for life-size displays, a perceptual-training experiment on decision-making in beach volleyball was conducted...
Tzeng, Christina Y; Alexander, Jessica E D; Sidaras, Sabrina K; Nygaard, Lynne C
Foreign-accented speech contains multiple sources of variation that listeners learn to accommodate. Extending previous findings showing that exposure to high-variation training facilitates perceptual learning of accented speech, the current study examines to what extent the structure of training materials affects learning. During training, native adult speakers of American English transcribed sentences spoken in English by native Spanish-speaking adults. In Experiment 1, training stimuli were blocked by speaker, sentence, or randomized with respect to speaker and sentence (Variable training). At test, listeners transcribed novel English sentences produced by unfamiliar Spanish-accented speakers. Listeners' transcription accuracy was highest in the Variable condition, suggesting that varying both speaker identity and sentence across training trials enabled listeners to generalize their learning to novel speakers and linguistic content. Experiment 2 assessed the extent to which ordering of training tokens by a single factor, speaker intelligibility, would facilitate speaker-independent accent learning, finding that listeners' test performance did not reliably differ from that in the no-training control condition. Overall, these results suggest that the structure of training exposure, specifically trial-to-trial variation on both speaker's voice and linguistic content, facilitates learning of the systematic properties of accented speech. The current findings suggest a crucial role of training structure in optimizing perceptual learning. Beyond characterizing the types of variation listeners encode in their representations of spoken utterances, theories of spoken language processing should incorporate the role of training structure in learning lawful variation in speech. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
Bernard, Jean-Baptiste; Arunkumar, Amit; Chung, Susana T L
In a previous study, Chung, Legge, and Cheung (2004) showed that training using repeated presentation of trigrams (sequences of three random letters) resulted in an increase in the size of the visual span (number of letters recognized in a glance) and reading speed in the normal periphery. In this study, we asked whether we could optimize the benefit of trigram training on reading speed by using trigrams more specific to the reading task (i.e., trigrams frequently used in the English language) and presenting them according to their frequencies of occurrence in normal English usage and observers' performance. Averaged across seven observers, our training paradigm (4 days of training) increased the size of the visual span by 6.44 bits, with an accompanied 63.6% increase in the maximum reading speed, compared with the values before training. However, these benefits were not statistically different from those of Chung, Legge, and Cheung (2004) using a random-trigram training paradigm. Our findings confirm the possibility of increasing the size of the visual span and reading speed in the normal periphery with perceptual learning, and suggest that the benefits of training on letter recognition and maximum reading speed may not be linked to the types of letter strings presented during training. Copyright © 2012 Elsevier Ltd. All rights reserved.
Esther Gómez Lacabex
Full Text Available http://dx.doi.org/10.5007/2175-8026.2008n55p173 This study examines the ability to identify the English phonological contrast full vowel-schwa by Spanish learners of English after two different types of training: auditory and articulatory. Perceptual performance was measured in isolated words in order to investigate the effect of training and in sentences to study the robustness of acquisition in generalizing to a context which was not used during training. Subjects were divided into three groups: two experimental groups, one undergoing perceptual training and one undergoing production based training, and a control group. Both experimental groups' perception of the reduced vowel improved significantly after training. Results indicated that students were able to generalize their reduced vowel identification abilities to the new context. The control group did not show any significant improvement. Our findings agree with studies that have demonstrated positive effects of phonetic training (Derwing. Munro & Wiebe, 1998; Rochet, 1995; Cenoz & García Lecumberri, 1995, 1999. Interestingly, the results also support the facilitating view between perception and production since production training proved beneficial in the development of perceptual abilities (Catford & Pisoni, 1970; Mathews, 1997. Finally, our data showed that training resulted in robust learning, since students were able generalize their improved perceptual abilities to a new context.
Esther Gómez Lacabex
Full Text Available This study examines the ability to identify the English phonological contrast full vowel-schwa by Spanish learners of English after two different types of training: auditory and articulatory. Perceptual performance was measured in isolated words in order to investigate the effect of training and in sentences to study the robustness of acquisition in generalizing to a context which was not used during training. Subjects were divided into three groups: two experimental groups, one undergoing perceptual training and one undergoing production based training, and a control group. Both experimental groups' perception of the reduced vowel improved significantly after training. Results indicated that students were able to generalize their reduced vowel identification abilities to the new context. The control group did not show any significant improvement. Our findings agree with studies that have demonstrated positive effects of phonetic training (Derwing. Munro & Wiebe, 1998; Rochet, 1995; Cenoz & García Lecumberri, 1995, 1999. Interestingly, the results also support the facilitating view between perception and production since production training proved beneficial in the development of perceptual abilities (Catford & Pisoni, 1970; Mathews, 1997. Finally, our data showed that training resulted in robust learning, since students were able generalize their improved perceptual abilities to a new context.
Full Text Available Recent major political uprisings are indicating the extent to which social learning Web 2.0 technologies, can infl uence change in informal learning settings. Recognition and a discussion of the potential of that infl uence in formal learning settings have only just begun. This article describes a study of an international distance learning project in 2004, using a variety of Web 2.0 technologies, including video-based web conferencing, that sought to initiate and respond to this urgent need for dialogue in the research. Self-selected participants took part in a 5-week English as a foreign language (EFL program, a joint NATO sponsored Canadian and Romanian Ministry of Defense-supported initiative. Clear evidence of linguistic knowledge construction and of important changes to participants’ learner identities, indicates the power of these technologies to support the kind of learning that can lead to the development of global citizens and the skills they will increasingly require in the 21st century.
Ubiratã Kickhöfel Alves
Full Text Available In this study, we investigate the effectiveness of perceptual training, administered to Argentinean learners, in the perception and production of word-initial voiceless stops in English. 24 participants were divided into 3 groups: (i Group 1, which participated in 3 training sessions; (ii Group 2, which, besides performing the same training tasks, was explicitly informed about the target item; (iii Group 3 (control. All participants took part in a pre-test, a post-test and a delayed post-test. In all these phases, they participated in a consonant identification task and took part in a reading exercise. Our results show a significant increase of both experimental groups in identification. As for production, Group 2 exhibited a significant increase in /p/ and /t/ after training. These results are indicative of the effectiveness of perceptual training tasks in helping learners focus on Voice Onset Time.
Full Text Available The capacity to process complex dynamic scenes is of critical importance in real life. For instance, travelling through a crowd while avoiding collisions and maintaining orientation and good motor control requires fluent and continuous perceptual-cognitive processing. It is well documented that effects of healthy aging can influence perceptual-cognitive processes (Faubert, 2002 and that the efficiency of such processes can improve with training even for older adults (Richards et al., 2006. Here we assess the capacity of older observers to learn complex dynamic visual scenes by using the 3D-multiple object tracking speed threshold protocol (Faubert & Sidebottom, 2012. Results show that this capacity is significantly affected by healthy aging but that perceptual-cognitive training can significantly reduce age-related effects in older individuals, who show an identical learning function to younger healthy adults. Data support the notion that plasticity in healthy older persons is maintained for processing complex dynamic scenes.
Ghaffarvand Mokari, Payam; Werner, Stefan
The present study attempts to extend the research on the effects of phonetic training on the production and perception of second-language (L2) vowels. We also examined whether success in learning L2 vowels through high-variability intensive phonetic training is related to the learners' general musical abilities. Forty Azerbaijani learners of Standard Southern British English participated in a pre-test/training/post-test setting. Discrimination and production tests were used in pre- and post-tests. The participants' musical ability was evaluated through three musical aptitude tests. Results revealed a significant improvement in the discrimination and production of L2 vowels after training. However, the lack of a one-to-one relationship between production and perception gains suggests distinct representations underlying L2 speech perception and production. There was no significant correlation between overall musical ability scores and L2 vowel learning, however, results revealed a correlation between discrimination improvements and tonal memory. This suggests tonal memory facilitates the perceptual learning of the novel phonological structure of L2.
Full Text Available Previous behavioral studies have shown that human perceptual learning (PL occurs not only within active training sessions but also between sessions when no actual training is conducted. Once acquired, the learning effect can last for a long term, from months to even years, without further training (Karni et al, Nature, 1993. It's not clear, however, whether fast (within-session and slow (between-session visual PL involves different neural mechanisms, and whether both contribute to the long-term preservation. Recently, by observing the time course of learning-associated ERP changes over a period of six months, we found that fast and slow learning involved distinct ERP changes, which played different role on the preservation of PL: while the ERP changes associated with fast learning can only last for a short term (several days, those associated with slow learning can be retained for a long-term (several months after training has been stopped. We have observed these findings in two distinct visual tasks: line orientation detection (Qu et al., Neuropsychologia, 2010 and vernier tasks (Ding et al., in preparation so far. A general model of PL was proposed based on our findings and literatures.
Deveau, Jenni; Lovcik, Gary; Seitz, Aaron R
... impacts on individuals' lives. Research in the field of perceptual learning has demonstrated that vision can be improved in both normally seeing and visually impaired individuals, however, a limitation of most perceptual learning...
Hopwood, M.; Mann, D.L.; Farrow, D.; Neilsen, T.
This study examined the effectiveness of visual-perceptual training for improving fielding performance in cricket. Twelve highly-skilled cricket players completed a video-based decision-making test and an in-situ fielding test before and after a six-week training intervention. During this period,
Wood, Milton E.
The purpose of the effort was to determine the benefits to be derived from the adaptive training technique of automatically adjusting task difficulty as a function of a student skill during early learning of a complex perceptual motor task. A digital computer provided the task dynamics, scoring, and adaptive control of a second-order, two-axis,…
Full Text Available Visual Perception is the mind’s ability to interpret or give meaning to what is seen with the eyes (WCED 2006. Grade Reception Phase (R teachers, of five and six year-old learners, need to impart Visual Perceptual Skills (VPS during visual training for pre-reading. These prereading activities in Grade R support early reading progress in Grade 1, which is critical for improving basic literacy and numeracy education in South Africa. A quality Grade R programme which can deliver these visual training outcomes depends on a progressive model for effective pre- and in-service professional development of teachers. A model implemented via academic-governmental collaboration. This article seeks to describe and recommend best practices of such professional development. The recommendations are based on an overview of the current Grade R professional development landscape, a brief exposition of the Subject Content Knowledge (SCK of VPS, a document analysis of the Curriculum and Assessment Policy Statement (CAPS curriculum and, finally, a case study with a discourse analysis involving four Grade R teachers.
Full Text Available A number of previous studies have examined music-related plasticity in terms of multi-sensory and motor integration but little is known about the functional and effective connectivity patterns of spontaneous intrinsic activity in these systems during the resting state in musicians. Using functional connectivity and Granger causal analysis, functional and effective connectivity among the motor and multi-sensory (visual, auditory and somatosensory cortices were evaluated using resting-state functional magnetic resonance imaging (fMRI in musicians and non-musicians. The results revealed that functional connectivity was significantly increased in the motor and multi-sensory cortices of musicians. Moreover, the Granger causality results demonstrated a significant increase outflow-inflow degree in the auditory cortex with the strongest causal outflow pattern of effective connectivity being found in musicians. These resting state fMRI findings indicate enhanced functional integration among the lower-level perceptual and motor networks in musicians, and may reflect functional consolidation (plasticity resulting from long-term musical training, involving both multi-sensory and motor functional integration.
Luo, Cheng; Guo, Zhi-wei; Lai, Yong-xiu; Liao, Wei; Liu, Qiang; Kendrick, Keith M; Yao, De-zhong; Li, Hong
A number of previous studies have examined music-related plasticity in terms of multi-sensory and motor integration but little is known about the functional and effective connectivity patterns of spontaneous intrinsic activity in these systems during the resting state in musicians. Using functional connectivity and Granger causal analysis, functional and effective connectivity among the motor and multi-sensory (visual, auditory and somatosensory) cortices were evaluated using resting-state functional magnetic resonance imaging (fMRI) in musicians and non-musicians. The results revealed that functional connectivity was significantly increased in the motor and multi-sensory cortices of musicians. Moreover, the Granger causality results demonstrated a significant increase outflow-inflow degree in the auditory cortex with the strongest causal outflow pattern of effective connectivity being found in musicians. These resting state fMRI findings indicate enhanced functional integration among the lower-level perceptual and motor networks in musicians, and may reflect functional consolidation (plasticity) resulting from long-term musical training, involving both multi-sensory and motor functional integration.
Gabay, Yafit; Karni, Avi; Banai, Karen
Speech perception can improve substantially with practice (perceptual learning) even in adults. Here we compared the effects of four training protocols that differed in whether and how task difficulty was changed during a training session, in terms of the gains attained and the ability to apply (transfer) these gains to previously un-encountered items (tokens) and to different talkers. Participants trained in judging the semantic plausibility of sentences presented as time-compressed speech and were tested on their ability to reproduce, in writing, the target sentences; trail-by-trial feedback was afforded in all training conditions. In two conditions task difficulty (low or high compression) was kept constant throughout the training session, whereas in the other two conditions task difficulty was changed in an adaptive manner (incrementally from easy to difficult, or using a staircase procedure). Compared to a control group (no training), all four protocols resulted in significant post-training improvement in the ability to reproduce the trained sentences accurately. However, training in the constant-high-compression protocol elicited the smallest gains in deciphering and reproducing trained items and in reproducing novel, untrained, items after training. Overall, these results suggest that training procedures that start off with relatively little signal distortion ("easy" items, not far removed from standard speech) may be advantageous compared to conditions wherein severe distortions are presented to participants from the very beginning of the training session.
Full Text Available Speech perception can improve substantially with practice (perceptual learning even in adults. Here we compared the effects of four training protocols that differed in whether and how task difficulty was changed during a training session, in terms of the gains attained and the ability to apply (transfer these gains to previously un-encountered items (tokens and to different talkers. Participants trained in judging the semantic plausibility of sentences presented as time-compressed speech and were tested on their ability to reproduce, in writing, the target sentences; trail-by-trial feedback was afforded in all training conditions. In two conditions task difficulty (low or high compression was kept constant throughout the training session, whereas in the other two conditions task difficulty was changed in an adaptive manner (incrementally from easy to difficult, or using a staircase procedure. Compared to a control group (no training, all four protocols resulted in significant post-training improvement in the ability to reproduce the trained sentences accurately. However, training in the constant-high-compression protocol elicited the smallest gains in deciphering and reproducing trained items and in reproducing novel, untrained, items after training. Overall, these results suggest that training procedures that start off with relatively little signal distortion ("easy" items, not far removed from standard speech may be advantageous compared to conditions wherein severe distortions are presented to participants from the very beginning of the training session.
Wang, Rui; Zhang, Jun-Yun; Klein, Stanley A.; Levi, Dennis M.; Yu, Cong
Perceptual learning, a process in which training improves visual discrimination, is often specific to the trained retinal location, and this location specificity is frequently regarded as an indication of neural plasticity in the retinotopic visual cortex. However, our previous studies have shown that “double training” enables location-specific perceptual learning, such as Vernier learning, to completely transfer to a new location where an irrelevant task is practiced. Here we show that Vernier learning can be actuated by less location-specific orientation or motion-direction learning to transfer to completely untrained retinal locations. This “piggybacking” effect occurs even if both tasks are trained at the same retinal location. However, piggybacking does not occur when the Vernier task is paired with a more location-specific contrast-discrimination task. This previously unknown complexity challenges the current understanding of perceptual learning and its specificity/transfer. Orientation and motion-direction learning, but not contrast and Vernier learning, appears to activate a global process that allows learning transfer to untrained locations. Moreover, when paired with orientation or motion-direction learning, Vernier learning may be “piggybacked” by the activated global process to transfer to other untrained retinal locations. How this task-specific global activation process is achieved is as yet unknown. PMID:25398974
Wan, Yi-Ting; Chiang, Ching-Sui; Chen, Sharon Chia-Ju; Wuang, Yee-Pay
This study investigated the effectiveness of the Computerized Visual Perception Training (CVPT) program on individuals with Down syndrome (DS, mean age=13.17±4.35years, age range: 6.54-20.75 years). All participants have mild intellectual disability classified by the standard IQ measures (mean=61.2, ranges from 55 to 68). Both the Test of Visual Perceptual Skill- Third Edition (TVPS-3) and functional magnetic resonance imaging (fMRI) were used to evaluate the training outcomes. Results of TVPS-3 and fMRI showed that DS group had visual perceptual deficits and abnormal neural networks related to visual organization. The results showed that DS intervention group had significant improvements on TVPS-3 after intervention. The fMRI results indicated more activation in superior and inferior parietal lobes (spatial manipulation), as well as precentral gyrus and dorsal premotor cortex (motor imagery) in DS intervention group. The CVPT program was effective in improving visual perceptual functions and enhancing associated cortical activations in DS. Copyright © 2017 Elsevier Ltd. All rights reserved.
Chaabène, H.; Franchini, E.; Tourny, C.; Chamari, K.; Coquart, J.
Objective The aim of the present study was to examine the influence of karate practice level (national vs international level) and sex (women vs men) on physiological and perceptual responses in three modern karate training modalities (tactical-technical (TT), technical-development (TD), and randori). Method The study included 18 karatekas participating in an eight-session training camp of four TT, two TD, and two randori. During each session, the percentage of maximal heart rate (HR), blood lactate concentration [La-], and rating of perceived exertion (RPE) were assessed. Results The main results showed that the percentage of maximal HR was significantly higher in women than in men regardless of practice level or training modality (70.3 ± 4.1 vs 66.2 ± 6.3, respectively). Moreover, [La-] and RPE were significantly lower in international-level karatekas compared with their national-level counterparts whatever the sex or training modality ([La-] = 11.4 ± 2.6 vs 8.3 ± 2.4 mmol · L-1 and RPE = 3.6 ± 1.2 vs 4.3 ± 1.5, respectively). Last, physiological and perceptual responses were significantly higher during randori in comparison with TT and TD for both sexes. Conclusion The combination of [La-] and RPE thus seems to be a good indicator for discriminating between national- and international-level karatekas, and randori seems to be an effective means to reproduce official karate sparring. PMID:25177098
Full Text Available Objective: The aim of the present study was to examine the influence of karate practice level (national vs international level and sex (women vs men on physiological and perceptual responses in three modern karate training modalities (tactical-technical (TT, technical-development (TD, and randori. Method: The study included 18 karatekas participating in an eight-session training camp of four TT, two TD, and two randori. During each session, the percentage of maximal heart rate (HR, blood lactate concentration [La-], and rating of perceived exertion (RPE were assessed. Results: The main results showed that the percentage of maximal HR was significantly higher in women than in men regardless of practice level or training modality (70.3 ± 4.1 vs 66.2 ± 6.3, respectively. Moreover, [La-] and RPE were significantly lower in international-level karatekas compared with their national-level counterparts whatever the sex or training modality ([La-] = 11.4 ± 2.6 vs 8.3 ± 2.4 mmol · L-1 and RPE = 3.6 ± 1.2 vs 4.3 ± 1.5, respectively. Last, physiological and perceptual responses were significantly higher during randori in comparison with TT and TD for both sexes. Conclusion: The combination of [La-] and RPE thus seems to be a good indicator for discriminating between national- and international-level karatekas, and randori seems to be an effective means to reproduce official karate sparring.
Friar, John T.
Two factors of predicted learning disorders were investigated: (1) inability to maintain appropriate classroom behavior (BEH), (2) perceptual discrimination deficit (PERC). Three groups of first-graders (BEH, PERC, normal control) were administered measures of impulse control, distractability, auditory discrimination, and visual discrimination.…
Galvin, K L; Blamey, P J; Cowan, R S; Oerlemans, M; Clark, G M
The Tickle Talker is an electrotactile speech perception device. Subjects were evaluated using the device in various tactile-alone and tactile-visual contexts to assess the generalization to other contexts of tactile-alone perceptual skills. The subjects were from a group of six normally hearing subjects who had previously received 12 to 33 h of tactile-alone word recognition training and had learned an average vocabulary of 50 words [Galvin et al., J. Acoust. Soc. Am. 106, 1084-1089 (1999)]. The tactile-alone evaluation contexts were sentences, unfamiliar talkers, and untrained words. The tactile-visual evaluation contexts were closed-set words, open-set words, and open-set sentences. Tactile-alone perceptual skills were generalized to unfamiliar speakers, sentences, and untrained words, though scores indicated that generalization was not complete. In contrast, the generalization of skills to tactile-visual contexts was minimal or absent. The potential value of tactile-alone training for hearing-impaired users of the Tickle Talker is discussed.
Full Text Available For perceptual-cognitive skill training, a variety of intervention methods has been proposed, including the so-called colour-cueing method which aims on superior gaze-path learning by applying visual markers. However, recent findings challenge this method, especially, with regards to its actual effects on gaze behaviour. Consequently, after a preparatory study on the identification of appropriate visual cues for life-size displays, a perceptual-training experiment on decision-making in beach volleyball was conducted, contrasting two cueing interventions (functional vs. dysfunctional gaze path with a conservative control condition (anticipation-related instructions. Gaze analyses revealed learning effects for the dysfunctional group only. Regarding decision-making, all groups showed enhanced performance with largest improvements for the control group followed by the functional and the dysfunctional group. Hence, the results confirm cueing effects on gaze behaviour, but they also question its benefit for enhancing decision-making. However, before completely denying the method’s value, optimisations should be checked regarding, for instance, cueing-pattern characteristics and gaze-related feedback.
Murphy, Alistair P; Duffield, Rob; Kellett, Aaron; Reid, Machar
High-performance tennis environments aim to prepare athletes for competitive demands through simulated-match scenarios and drills. With a dearth of direct comparisons between training and tournament demands, the current investigation compared the perceptual and technical characteristics of training drills, simulated match play, and tournament matches. Data were collected from 18 high-performance junior tennis players (gender: 10 male, 8 female; age 16 ± 1.1 y) during 6 ± 2 drill-based training sessions, 5 ± 2 simulated match-play sessions, and 5 ± 3 tournament matches from each participant. Tournament matches were further distinguished by win or loss and against seeded or nonseeded opponents. Notational analysis of stroke and error rates, winners, and serves, along with rating of perceived physical exertion (RPE) and mental exertion was measured postsession. Repeated-measures analyses of variance and effect-size analysis revealed that training sessions were significantly shorter in duration than tournament matches (P .05; d = 1.26, d = 1.05, respectively). Mental exertion in training was lower than in both simulated match play and tournaments (P > .05; d = 1.10, d = 0.86, respectively). Stroke rates during tournaments exceeded those observed in training (P .05, d preparation.
Bate, Sarah; Bennetts, Rachel; Mole, Joseph A; Ainge, James A; Gregory, Nicola J; Bobak, Anna K; Bussunt, Amanda
In this paper we describe the case of EM, a female adolescent who acquired prosopagnosia following encephalitis at the age of eight. Initial neuropsychological and eye-movement investigations indicated that EM had profound difficulties in face perception as well as face recognition. EM underwent 14 weeks of perceptual training in an online programme that attempted to improve her ability to make fine-grained discriminations between faces. Following training, EM's face perception skills had improved, and the effect generalised to untrained faces. Eye-movement analyses also indicated that EM spent more time viewing the inner facial features post-training. Examination of EM's face recognition skills revealed an improvement in her recognition of personally-known faces when presented in a laboratory-based test, although the same gains were not noted in her everyday experiences with these faces. In addition, EM did not improve on a test assessing the recognition of newly encoded faces. One month after training, EM had maintained the improvement on the eye-tracking test, and to a lesser extent, her performance on the familiar faces test. This pattern of findings is interpreted as promising evidence that the programme can improve face perception skills, and with some adjustments, may at least partially improve face recognition skills.
Bernstein, Lynne E.; Eberhardt, Silvio P.; Auer, Edward T.
Training with audiovisual (AV) speech has been shown to promote auditory perceptual learning of vocoded acoustic speech by adults with normal hearing. In Experiment 1, we investigated whether AV speech promotes auditory-only (AO) perceptual learning in prelingually deafened adults with late-acquired cochlear implants. Participants were assigned to learn associations between spoken disyllabic C(=consonant)V(=vowel)CVC non-sense words and non-sense pictures (fribbles), under AV and then AO (AV-AO; or counter-balanced AO then AV, AO-AV, during Periods 1 then 2) training conditions. After training on each list of paired-associates (PA), testing was carried out AO. Across all training, AO PA test scores improved (7.2 percentage points) as did identification of consonants in new untrained CVCVC stimuli (3.5 percentage points). However, there was evidence that AV training impeded immediate AO perceptual learning: During Period-1, training scores across AV and AO conditions were not different, but AO test scores were dramatically lower in the AV-trained participants. During Period-2 AO training, the AV-AO participants obtained significantly higher AO test scores, demonstrating their ability to learn the auditory speech. Across both orders of training, whenever training was AV, AO test scores were significantly lower than training scores. Experiment 2 repeated the procedures with vocoded speech and 43 normal-hearing adults. Following AV training, their AO test scores were as high as or higher than following AO training. Also, their CVCVC identification scores patterned differently than those of the cochlear implant users. In Experiment 1, initial consonants were most accurate, and in Experiment 2, medial consonants were most accurate. We suggest that our results are consistent with a multisensory reverse hierarchy theory, which predicts that, whenever possible, perceivers carry out perceptual tasks immediately based on the experience and biases they bring to the task. We
Lev, Maria; Gilaie-Dotan, Sharon; Gotthilf-Nezri, Dana; Yehezkel, Oren; Brooks, Joseph L.; Perry, Anat; Bentin, Shlomo; Bonneh, Yoram; Polat, Uri
Long-term deprivation of normal visual inputs can cause perceptual impairments at various levels of visual function, from basic visual acuity deficits, through mid-level deficits such as contour integration and motion coherence, to high-level face and object agnosia. Yet it is unclear whether training during adulthood, at a post-developmental…
Dosher, Barbara; Lu, Zhong-Lin
Visual perceptual learning through practice or training can significantly improve performance on visual tasks. Originally seen as a manifestation of plasticity in the primary visual cortex, perceptual learning is more readily understood as improvements in the function of brain networks that integrate processes, including sensory representations, decision, attention, and reward, and balance plasticity with system stability. This review considers the primary phenomena of perceptual learning, theories of perceptual learning, and perceptual learning's effect on signal and noise in visual processing and decision. Models, especially computational models, play a key role in behavioral and physiological investigations of the mechanisms of perceptual learning and for understanding, predicting, and optimizing human perceptual processes, learning, and performance. Performance improvements resulting from reweighting or readout of sensory inputs to decision provide a strong theoretical framework for interpreting perceptual learning and transfer that may prove useful in optimizing learning in real-world applications.
Ghaffarvand Mokari, Payam; Werner, Stefan
The present study attempts to extend the research on the effects of phonetic training on the production and perception of second-language (L2) vowels. We also examined whether success in learning L2 vowels through high-variability intensive phonetic training is related to the learners' general musical abilities. Forty Azerbaijani learners of…
Full Text Available In a previous report we showed that cognitive training fostering auditory-verbal discrimination and working memory normalized magnetoencephalographic (MEG M50 gating ratio in schizophrenia patients. The present analysis addressed whether training effects on M50 ratio and task performance are mediated by changes in brain oscillatory activity. Such evidence should improve understanding of the role of oscillatory activity in phenomena such as M50 ratio, the role of dysfunctional oscillatory activity in processing abnormalities in schizophrenia, and mechanisms of action of cognitive training.Time-locked and non-time-locked oscillatory activity was measured together with M50 ratio in a paired-click design before and after a 4-week training of 36 patients randomly assigned to specific cognitive exercises (CE or standard (comparison cognitive training (CP. Patient data were compared to those of 15 healthy controls who participated in two MEG measurements 4 weeks apart without training. Training led to more time-locked gamma-band response and more non-time-locked alpha-band desynchronization, moreso after CE than after CP. Only after CE, increased alpha desynchronization was associated with normalized M50 ratio and with improved verbal memory performance. Thus, both types of cognitive training normalized gamma activity, associated with improved stimulus encoding. More targeted training of auditory-verbal discrimination and memory additionally normalized alpha desynchronization, associated with improved elaborative processing. The latter presumably contributes to improved auditory gating and cognitive function.Results suggest that dysfunctional interplay of ocillatory activity that may contribute to auditory processing disruption in schizophrenia can be modified by targeted training.
Cassey, Peter J; Gaut, Garren; Steyvers, Mark; Brown, Scott D
Theory development in both psychology and neuroscience can benefit by consideration of both behavioral and neural data sets. However, the development of appropriate methods for linking these data sets is a difficult statistical and conceptual problem. Over the past decades, different linking approaches have been employed in the study of perceptual decision-making, beginning with rudimentary linking of the data sets at a qualitative, structural level, culminating in sophisticated statistical approaches with quantitative links. We outline a new approach, in which a single model is developed that jointly addresses neural and behavioral data. This approach allows for specification and testing of quantitative links between neural and behavioral aspects of the model. Estimating the model in a Bayesian framework allows both data sets to equally inform the estimation of all model parameters. The use of a hierarchical model architecture allows for a model, which accounts for and measures the variability between neurons. We demonstrate the approach by re-analysis of a classic data set containing behavioral recordings of decision-making with accompanying single-cell neural recordings. The joint model is able to capture most aspects of both data sets, and also supports the analysis of interesting questions about prediction, including predicting the times at which responses are made, and the corresponding neural firing rates.
Bao, Tianlong; Ding, Chunhui; Karmoshi, Saleem; Zhu, Ming
Face recognition has been widely studied recently while video-based face recognition still remains a challenging task because of the low quality and large intra-class variation of video captured face images. In this paper, we focus on two scenarios of video-based face recognition: 1)Still-to-Video(S2V) face recognition, i.e., querying a still face image against a gallery of video sequences; 2)Video-to-Still(V2S) face recognition, in contrast to S2V scenario. A novel method was proposed in this paper to transfer still and video face images to an Euclidean space by a carefully designed convolutional neural network, then Euclidean metrics are used to measure the distance between still and video images. Identities of still and video images that group as pairs are used as supervision. In the training stage, a joint loss function that measures the Euclidean distance between the predicted features of training pairs and expanding vectors of still images is optimized to minimize the intra-class variation while the inter-class variation is guaranteed due to the large margin of still images. Transferred features are finally learned via the designed convolutional neural network. Experiments are performed on COX face dataset. Experimental results show that our method achieves reliable performance compared with other state-of-the-art methods.
Wouters, Pieter; Tabbers, Huib; Paas, Fred
textabstractIn this review we argue that interactivity can be effective in video-based models to engage learners in relevant cognitive processes. We do not treat modeling as an isolated instructional method but adopted the social cognitive model of sequential skill acquisition in which learners start with observation and finish with independent, self-regulated performance. Moreover, we concur with the notion that interactivity should emphasize the cognitive processes that learners engage in w...
Full Text Available Background: the aim of this pilot study was to evaluate whether proprioceptive-motor training using the Wii Balance Board (WBB might improve postural sway in healthy subjects.Methods: twenty-five healthy subjects were trained for six weeks (two sessions per week with 5 “video games”: Wii Fit Plus (WFP program. Before and after training: Basic Balance, Single-leg Balance, Agility, Stability and Motion (lower limb: right-left and both leg were measured using the Wii Balance Board.Results: the Wilcoxon Test showed improvements at the end of the training program compared to the baseline conditions. Basic Balance increased during the WFP (33.33% and was associated with a 19.92% decrease in center of pressure (COP lenght. The Single-leg Balance results incremented after the WFP (left 29.09% vs. right 47.92% and accompanied by a decrement in COP (left 28.71% vs. right 30.45%. The values for the Agility test increased both in WFP and COP (28.57% and 58.57%, respectively. The Stability test scores increased in the WFP (66.67% along with a consequent decrease in COP (10.53%. Finally, the Motion test values increased in the WFP (73.17%, whilst COP for this test decreased (12.02%. These results indicate that 6 weeks of virtual training produced a good adaptability. Younger participants (<20 years demonstrated to be more responsive to dynamic stimulation with respect to those >20 years.Conclusions: significant improvements in all participants were observed, indicating that virtual training can influence posture and balance in healthy people. Because of its characteristics of low cost and easy availability, a portable system for balance training for everyone offers the possibility to more readily measure motor skill and to gauge improvement.
Montgomery, Paul G; Hopkins, Will G
Australian Football is an intense team sport played over ~120 min on a weekly basis. To determine the effects of game and training load on muscle soreness and the time frame of soreness dissipation, 64 elite Australian Football players (age 23.8 ± 1.8 y, height 183.9 ± 3.8 cm, weight 83.2 ± 5.0 kg; mean ± SD) recorded perceptions of muscle soreness, game intensity, and training intensity on scales of 1-10 on most mornings for up to 3 competition seasons. Playing and training times were also recorded in minutes. Data were analyzed with a mixed linear model, and magnitudes of effects on soreness were evaluated by standardization. All effects had acceptably low uncertainty. Game and training-session loads were 790 ± 182 and 229 ± 98 intensity-minutes (mean ± SD), respectively. General muscle soreness was 4.6 ± 1.1 units on d 1 postgame and fell to 1.9 ± 1.0 by d 6. There was a small increase in general muscle soreness (0.22 ± 0.07-0.50 ± 0.13 units) in the 3 d after high-load games relative to low-load games. Other soreness responses showed similar timelines and magnitudes of change. Training sessions made only small contributions to soreness over the 3 d after each session. Practitioners should be aware of these responses when planning weekly training and recovery programs, as it appears that game-related soreness dissipates after 3 d regardless of game load and increased training loads in the following week produce only small increases in soreness.
Schorer, Jörg; Loffing, Florian; Hagemann, Norbert; Baker, Joseph
Left-handed performers seem to enjoy an advantage in interactive sports. Researchers suggest this is predominantly due to the relative scarcity of left-handers compared with right-handers. Such negative frequency-dependent advantages are likely to appear in inefficient game-play behaviour against left-handed opponents such as reduced ability to correctly anticipate left-handers' action intentions. We used a pre-post retention design to test whether such negative frequency-dependent perceptual effects can be reversed via effective training. In a video-based test, 30 handball novices anticipated the shot outcome of temporally occluded handball penalties thrown by right- and left-handed players. Between the pre- and post-tests, participants underwent a perceptual training programme to improve prediction accuracy, followed by an unfilled retention test one week later. Participants were divided into two hand-specific training groups (i.e. only right- or left-handed shots were presented during training) and a mixed group (i.e. both right- and left-handed shots were presented). Our results support the negative frequency-dependent advantage hypothesis, as hand-specific perceptual training led to side-specific improvement of anticipation skills. Similarly, findings provide experimental evidence to support the contention that negatively frequency-dependent selection mechanisms contributed to the maintenance of the handedness polymorphism.
Fitschen, P J; Kistler, B M; Jeong, J H; Chung, H R; Wu, P T; Walsh, M J; Wilund, K R
Blood flow restriction (BFR) exercise may be an alternative form of resistance training; however, a side of effect of BFR resistance exercise is acute muscle pain. Typically, BFR exercise studies restrict blood flow with a cuff continuously during the exercise bout, including rest periods. However, others have used intermittent BFR where the cuff is inflated only during sets. We performed two studies to compare intermittent and continuous BFR exercise. In study one, eleven subjects randomly proceeded through three treatments of unilateral leg extensions to failure: (i) continuous BFR, (ii) intermittent BFR and (iii) control (exercise without BFR). Pain measurements were taken immediately after each set. In study two, subjects (n = 32) underwent a 5-week resistance training programme after random assignment to one of the three conditions. Lean mass and strength were assessed at baseline and after training. Continuous BFR resulted in significantly greater pain than intermittent BFR or control. Both BFR conditions resulted in significantly fewer repetitions to failure than control. This suggests that an acute bout of intermittent BFR exercise may produce as much muscle fatigue as an acute bout of continuous BFR exercise, but with less pain. With training, maximal knee extension (P = 0·033) and maximum knee flexion (P = 0·007) strength increased among all groups. There were no significant differences between groups in strength or lean mass. These results suggest that short-term low-load resistance training increases muscle strength to a similar extent as low-load resistance training without BFR. © 2013 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.
Antigone S Papavasiliou
Full Text Available Antigone S Papavasiliou, Irene Nikaina, Ioanna Rizou, Stratos AlexandrouDepartment of Neurology, Pendeli Children’s Hospital, Athens, GreeceAbstract: Attention deficit hyperactivity disorder (ADHD is treated with stimulants and psycho-educational remedial programs despite limited literature support for the latter. This study aimed to examine changes in a “Test of Visual Perceptual Skills” (TVPS that has not been previously reported in children with ADHD enrolled in such a program.Methods: Sixteen children, 7–11 years old, with ADHD were involved in occupational therapy and special education geared towards attention training. Six months later methylphenidate 1 mg/kg/day was prescribed. It was not taken by eight children because of family choice. The TVPS was given twice, upon diagnosis, and 8 months post-intervention. The groups were compared by a repeated measures analysis of variance (ANOVA with medication as a between groups factor and test-retest scores as within factor.Results: All children demonstrated increases in total scores in the second measurement. Medicated children scored higher but ANOVA showed a nonsignificant F for the two groups, medicated and unmedicated (F = 0.0031, p = 0.9563, indicating a non-differential effect of the two levels of treatment. It revealed a significant F for the pre- and post-treatment total TVPS scores (F = 30.91, p < 0.0001 indicating a significant difference between pre- and post-treatment tests. The interaction between pre-post treatment and level of treatment (medicated–unmedicated was nonsignificant (F = 2.20, p = 0.1604.Conclusion: TVPS scores improved in all children following intervention. Medicated children did better, but differences were nonsignificant.Keywords: ADHD, stimulants, psycho-educational therapy, TVPS
Video-based teaching material is a rich and powerful medium being used in computer assisted learning. This paper aimed to assess the learning outcomes and student nurses' acceptance and satisfaction with the video-based lectures versus the traditional method of teaching human anatomy and physiology courses.
de Souza Ana Cláudia Silva
Full Text Available Abstract Background There is an accumulating body of evidence indicating that neuronal functional specificity to basic sensory stimulation is mutable and subject to experience. Although fMRI experiments have investigated changes in brain activity after relative to before perceptual learning, brain activity during perceptual learning has not been explored. This work investigated brain activity related to auditory frequency discrimination learning using a variational Bayesian approach for source localization, during simultaneous EEG and fMRI recording. We investigated whether the practice effects are determined solely by activity in stimulus-driven mechanisms or whether high-level attentional mechanisms, which are linked to the perceptual task, control the learning process. Results The results of fMRI analyses revealed significant attention and learning related activity in left and right superior temporal gyrus STG as well as the left inferior frontal gyrus IFG. Current source localization of simultaneously recorded EEG data was estimated using a variational Bayesian method. Analysis of current localized to the left inferior frontal gyrus and the right superior temporal gyrus revealed gamma band activity correlated with behavioral performance. Conclusions Rapid improvement in task performance is accompanied by plastic changes in the sensory cortex as well as superior areas gated by selective attention. Together the fMRI and EEG results suggest that gamma band activity in the right STG and left IFG plays an important role during perceptual learning.
Abrahamse, E.L.; Noordzij, Matthijs Leendert
Within various contexts, such as sports and the military, training programs are being designed to effectively and efficiently guide perceptual-motor skill acquisition. Even though this notion is often underestimated, the design of such training programs may greatly benefit from findings and theories
Angehrn, Albert; Maxwell, Katrina
Angehrn, A. A., & Maxwell, K. (2008). TENTube: A video-based connection tool supporting competence development. In H. W. Sligte & R. Koper (Eds.), Proceedings of the 4th TENCompetence Open Workshop. Empowering Learners for Lifelong Competence Development: pedagogical, organisational and
Ripamonti, Caterina; Westland, Stephen
We suggest that color constancy and perceptual transparency might be explained by the same underlying mechanism. For color constancy, Foster and Nascimento (1994) found that cone-excitation ratios between surfaces seen under one illuminant and cone-excitation ratios between the same surfaces seen under a different illuminant were almost constant. In the case of perceptual transparency we also found that cone-excitation ratios between surfaces illuminated directly and cone-excitation ratios between the same surfaces seen through a transparent filter were almost invariant (Westland and Ripamonti, 2000). We compare the ability of the cone-excitation-ratio invariance model to predict perceptual transparency with an alternative model based on convergence in color space (D'Zmura et al., 1997). Psychophysical data are reported from experiments where by subjects were asked to select which of two stimuli represented a Mondrian image partially covered by a homogeneous transparent filter. One of the stimuli was generated from the convergence model and the other was a modified version of the first stimulus such that the cone- excitation ratios were perfectly invariant. Subjects consistently selected the invariant stimulus confirming our hypothesis that perception of transparency is predicted by the degree of deviation frm an invariant ratio for the cone excitations.
Ahmet, Akgul; Gamze, Kus; Rustem, Mustafaoglu; Sezen, Karaborklu Argut
Visual signs draw more attention during the learning process. Video is one of the most effective tool including a lot of visual cues. This systematic review set out to explore the influence of video in surgical education. We reviewed the current evidence for the video-based surgical education methods, discuss the advantages and disadvantages on the teaching of technical and nontechnical surgical skills. This systematic review was conducted according to the guidelines defined in the preferred reporting items for systematic reviews and meta-analyses statement. The electronic databases: the Cochrane Library, Medline (PubMED), and ProQuest were searched from their inception to the 30 January 2016. The Medical Subject Headings (MeSH) terms and keywords used were "video," "education," and "surgery." We analyzed all full-texts, randomised and nonrandomised clinical trials and observational studies including video-based education methods about any surgery. "Education" means a medical resident's or student's training and teaching process; not patients' education. We did not impose restrictions about language or publication date. A total of nine articles which met inclusion criteria were included. These trials enrolled 507 participants and the total number of participants per trial ranged from 10 to 172. Nearly all of the studies reviewed report significant knowledge gain from video-based education techniques. The findings of this systematic review provide fair to good quality studies to demonstrate significant gains in knowledge compared with traditional teaching. Additional video to simulator exercise or 3D animations has beneficial effects on training time, learning duration, acquisition of surgical skills, and trainee's satisfaction. Video-based education has potential for use in surgical education as trainees face significant barriers in their practice. This method is effective according to the recent literature. Video should be used in addition to standard techniques
Lynne E Bernstein
Full Text Available Training with audiovisual (AO speech can promote auditory perceptual learning of vocoded acoustic speech by adults with normal hearing. Pre-/perilingually deafened adults rely on visual speech even when they also use a cochlear implant. This study investigated whether visual speech promotes auditory perceptual learning in these cochlear implant users. In Experiment 1, 28 prelingually deafened adults with late-acquired cochlear implants were assigned to learn paired associations between spoken disyllabic C(=consonantV(=vowelCVC nonsense words and nonsense pictures (fribbles, under AV and then under auditory-only (AO (or counter-balanced AO then AV training conditions. After training on each list of paired-associates (PA, testing was carried out AO. Across AV and AO training, AO PA test scores improved as did identification of consonants in untrained CVCVC stimuli. However, whenever PA training was carried out with AV stimuli, AO test scores were steeply reduced. Experiment 2 repeated the experiment with 43 normal-hearing adults. Their AO tests scores did not drop following AV PA training and even increased relative to scores following AO training. Normal-hearing participants' consonant identification scores improved also but with a pattern that contrasted with cochlear implant users’: Normal hearing adults were most accurate for medial consonants, and in contrast cochlear implant users were most accurate for initial consonants. The results are interpreted within a multisensory reverse hierarchy theory, which predicts that perceptual tasks are carried out whenever possible based on immediate high-level perception without scrutiny of lower-level features. The theory implies that, based on their bias towards visual speech, cochlear implant participants learned the PAs with greater reliance on vision to the detriment of auditory perceptual learning. Normal-hearing participants' learning took advantage of the concurrence between auditory and visual
White, Mark G.
A video-based format was used during a graduate seminar course designed to educate students on the nature of catalysis, to help transfer information among students working on similar problems, and to improve communication skills. The mechanics of and student reaction to this seminar course are discussed. (JN)
Bard, Chantal; And Others
Tested children's transfer of training in performance of coincidence-anticipation task. At an experimental apparatus, children attempted to intercept a fixed or moving target by pressing a button or by sliding a disk (the criterion task). Found that improved accuracy in intercepting the moving target by sliding the disk occurred only when children…
Hu, Yue-Yung; Mazer, Laura M; Yule, Steven J; Arriaga, Alexander F; Greenberg, Caprice C; Lipsitz, Stuart R; Gawande, Atul A; Smink, Douglas S
Surgical expertise demands technical and nontechnical skills. Traditionally, surgical trainees acquired these skills in the operating room; however, operative time for residents has decreased with duty hour restrictions. As in other professions, video analysis may help maximize the learning experience. To develop and evaluate a postoperative video-based coaching intervention for residents. In this mixed methods analysis, 10 senior (postgraduate year 4 and 5) residents were videorecorded operating with an attending surgeon at an academic tertiary care hospital. Each video formed the basis of a 1-hour one-on-one coaching session conducted by the operative attending; although a coaching framework was provided, participants determined the specific content collaboratively. Teaching points were identified in the operating room and the video-based coaching sessions; iterative inductive coding, followed by thematic analysis, was performed. Teaching points made in the operating room were compared with those in the video-based coaching sessions with respect to initiator, content, and teaching technique, adjusting for time. Among 10 cases, surgeons made more teaching points per unit time (63.0 vs 102.7 per hour) while coaching. Teaching in the video-based coaching sessions was more resident centered; attendings were more inquisitive about residents' learning needs (3.30 vs 0.28, P = .04), and residents took more initiative to direct their education (27% [198 of 729 teaching points] vs 17% [331 of 1977 teaching points], P coaching is a novel and feasible modality for supplementing intraoperative learning. Objective evaluation demonstrates that video-based coaching may be particularly useful for teaching higher-level concepts, such as decision making, and for individualizing instruction and feedback to each resident.
Kilduff Liam P
Full Text Available Abstract Background The present study examined putative modulators and indices of brain serotonergic and dopaminergic function, perceptual responses, and endurance exercise performance following caffeine co-ingested with a high fat meal. Methods Trained humans (n = 10 performed three constant-load cycling tests at 73% of maximal oxygen uptake (VO2max until exhaustion at 10°C remove space throughout. Prior to the first test, subjects consumed a 90% carbohydrate meal (Control trial and for the remaining two tests, a 90% fat meal with (FC trial and without (F trial caffeine. Results Time to exhaustion was not different between the F and FC trials (P > 0.05; [Control trial: 116(88-145 min; F trial: 122(96-144 min; FC trial: 127(107-176 min]. However, leg muscular discomfort during exercise was significantly lower on the FC relative to F trial (P P > 0.05 with the exception of plasma free-Trp:LNAA ratio which was higher at 90 min and at exhaustion during the FC trial (P Conclusions Neither brain 5-HT nor DA systems would appear to be implicated in the fatigue process when exercise is performed without significant thermoregulatory stress, thus indicating fatigue development during exercise in relatively cold temperatures to occur predominantly due to glycogen depletion.
Karimi Moonaghi, Hossein; Hasanzadeh, Farzaneh; Shamsoddini, Somayyeh; Emamimoghadam, Zahra; Ebrahimzadeh, Saeed
Adherence to diet and fluids is the cornerstone of patients undergoing hemodialysis. By informing hemodialysis patients we can help them have a proper diet and reduce mortality and complications of toxins. Face to face education is one of the most common methods of training in health care system. But advantages of video- based education are being simple and cost-effective, although this method is virtual. Seventy-five hemodialysis patients were divided randomly into face to face and video-based education groups. A training manual was designed based on Orem's self-care model. Content of training manual was same in both the groups. In the face to face group, 2 educational sessions were accomplished during dialysis with a 1-week time interval. In the video-based education group, a produced film, separated to 2 episodes was presented during dialysis with a 1-week time interval. An Attitude questionnaire was completed as a pretest and at the end of weeks 2 and 4. SPSS software version 11.5 was used for analysis. Attitudes about fluid and diet adherence at the end of weeks 2 and 4 are not significantly different in face to face or video-based education groups. The patients' attitude had a significant difference in face to face group between the 3 study phases (pre-, 2, and 4 weeks postintervention). The same results were obtained in 3 phases of video-based education group. Our findings showed that video-based education could be as effective as face to face method. It is recommended that more investment be devoted to video-based education.
Dagnaes-Hansen, Julia; Mahmood, Oria; Bube, Sarah
OBJECTIVE: Direct observation in assessment of clinical skills is prone to bias, demands the observer to be present at a certain location at a specific time, and is time-consuming. Video-based assessment could remove the risk of bias, increase flexibility, and reduce the time spent on assessment....... This study investigated if video-based assessment was a reliable tool for cystoscopy and if direct observers were prone to bias compared with video-raters. DESIGN: This study was a blinded observational trial. Twenty medical students and 9 urologists were recorded during 2 cystoscopies and rated by a direct...... observer and subsequently by 2 blinded video-raters on a global rating scale (GRS) for cystoscopy. Both intrarater and interrater reliability were explored. Furthermore, direct observer bias was explored by a paired samples t-test. RESULTS: Intrarater reliability calculated by Pearson's r was 0...
Ömer Faruk VURAL
Full Text Available Video-based learning has been extensively incorporated to enhance instruction. The advanced communication technology has greatly increased the possibilities and relative value of delivering instructional video content in onlineeducation applications. Simple watching instructional video often results in poor learning outcomes. Therefore, current video-based learning resources are used in combination with other teaching methods. Concept mapping, one of teaching methods, can provide another form of this type of interactivity and may enhance the active learning capacity. The new learning tool, which consisted of video viewer, supporting text, and interactive concept map, was developed to investigate the effect of time spent interacting with the learning tool by creating concept maps relate to student achievement. The study results showed that there was no relationship found between student achievement and time spent interacting with the learning tool
Winston, Karin; Grendarova, Petra; Rabi, Doreen
This study reviews the published literature on the use of video-based decision aids (DA) for patients. The authors describe the areas of medicine in which video-based patient DA have been evaluated, the medical decisions targeted, their reported impact, in which countries studies are being conducted, and publication trends. The literature review was conducted systematically using Medline, Embase, CINAHL, PsychInfo, and Pubmed databases from inception to 2016. References of identified studies were reviewed, and hand-searches of relevant journals were conducted. 488 studies were included and organized based on predefined study characteristics. The most common decisions addressed were cancer screening, risk reduction, advance care planning, and adherence to provider recommendations. Most studies had sample sizes of fewer than 300, and most were performed in the United States. Outcomes were generally reported as positive. This field of study was relatively unknown before 1990s but the number of studies published annually continues to increase. Videos are largely positive interventions but there are significant remaining knowledge gaps including generalizability across populations. Clinicians should consider incorporating video-based DA in their patient interactions. Future research should focus on less studied areas and the mechanisms underlying effective patient decision aids. Copyright © 2017 Elsevier B.V. All rights reserved.
Adhikari, Sam; Stark, David E
This paper presents a video-based eye-tracking method, ideally deployed via a mobile device or laptop-based webcam, as a tool for measuring brain function. Eye movements and pupillary motility are tightly regulated by brain circuits, are subtly perturbed by many disease states, and are measurable using video-based methods. Quantitative measurement of eye movement by readily available webcams may enable early detection and diagnosis, as well as remote/serial monitoring, of neurological and neuropsychiatric disorders. We successfully extracted computational and semantic features for 14 testing sessions, comprising 42 individual video blocks and approximately 17,000 image frames generated across several days of testing. Here, we demonstrate the feasibility of collecting video-based eye-tracking data from a standard webcam in order to assess psychomotor function. Furthermore, we were able to demonstrate through systematic analysis of this data set that eye-tracking features (in particular, radial and tangential variance on a circular visual-tracking paradigm) predict performance on well-validated psychomotor tests. © 2017 New York Academy of Sciences.
The effectiveness of video-based training of an electronic medical record system: An exploratory study on computer literate health workers in rural Uganda : Ändamålsenligheten hos videobaserad undervisning av ett elektroniskt patientjournalsystem: en explorativ studie av datorvana sjukvårdsarbetare på Ugandas landsbygd
Aims The purpose of this study is to explore the possibilities for video-based learning of computer systems in the field of medical education in rural sub-Saharan Africa. Background Low-income countries are forced to perform healthcare services with resources already spread too thin. The use of electronic medical records can increase the cost-effectiveness of delivering healthcare services, but the low computer literacy in sub-Saharan Africa is an obstacle necessary to overcome. E-learning an...
Yoo, M S; Son, Y J; Kim, Y S; Park, J H
This research was performed to investigate the effects of video-based self-assessment on the ability of nursing students to accurately measure vital signs, their communication skills, and their satisfaction. This research was conducted between March 2007 and June 2007 as a quasi-experimental control-group, pretest-posttest design. The study population was composed of 40 second-year student nurses who enrolled in a fundamentals of nursing course of a college of nursing, Ajou University in Korea. Results of the research indicate that there was a statistically significant difference in exam scores for assessing long-term memory video-review group demonstrating higher scores. Student satisfaction was also significantly higher in the video-review group than in the control group. These results may suggest video-based self-assessment is a beneficial and effective instructional method of training undergraduate nursing students to develop awareness of their strengths and weaknesses, and to improve their clinical and communication skills.
Full Text Available Load Theory (Lavie, 1995; 2005 states that the level of perceptual load in a task (i.e. the amount of information involved in processing task-relevant stimuli determines the efficiency of selective attention. There is evidence that perceptual load affects distractor processing, with increased inattentional blindness under high load. Given that high load can result in individuals failing to report seeing obvious objects, it is conceivable that load may also impair memory for the scene. The current study is the first to assess the effect of perceptual load on eyewitness memory. Across three experiments (two video-based and one in a driving simulator, the effect of perceptual load on eyewitness memory was assessed. The results showed that eyewitnesses were less accurate under high load, in particular for peripheral details. For example, memory for the central character in the video was not affected by load but memory for a witness who passed by the window at the edge of the scene was significantly worse under high load. High load memories were also more open to suggestion, showing increased susceptibility to leading questions. High visual perceptual load also affected recall for auditory information, illustrating a possible cross-modal perceptual load effect on memory accuracy. These results have implications for eyewitness memory researchers and forensic professionals.
Lindsay, C J; Moore, D W; Anderson, A; Dillenburger, K
The aim of this paper is to bridge the gap between the corpus of imitation research and video-based intervention (VBI) research, and consider the impact imitation skills may be having on VBI outcomes and highlight potential areas for improving efficacy. A review of the imitation literature was conducted focusing on imitation skill deficits in children with autism followed by a critical review of the video modelling literature focusing on pre-intervention assessment of imitation skills and the impact imitation deficits may have on VBI outcomes. Children with autism have specific imitation deficits, which may impact VBI outcomes. Imitation training or procedural modifications made to videos may accommodate for these deficits. There are only six studies where VBI researchers have taken pre-intervention imitation assessments using an assortment of imitation measures. More research is required to develop a standardised multi-dimensional imitation assessment battery that can better inform VBI.
Davies-Thompson, Jodie; Fletcher, Kimberley; Hills, Charlotte; Pancaroglu, Raika; Corrow, Sherryse L; Barton, Jason J S
Despite many studies of acquired prosopagnosia, there have been only a few attempts at its rehabilitation, all in single cases, with a variety of mnemonic or perceptual approaches, and of variable efficacy. In a cohort with acquired prosopagnosia, we evaluated a perceptual learning program that incorporated variations in view and expression, which was aimed at training perceptual stages of face processing with an emphasis on ecological validity. Ten patients undertook an 11-week face training program and an 11-week control task. Training required shape discrimination between morphed facial images, whose similarity was manipulated by a staircase procedure to keep training near a perceptual threshold. Training progressed from blocks of neutral faces in frontal view through increasing variations in view and expression. Whereas the control task did not change perception, training improved perceptual sensitivity for the trained faces and generalized to new untrained expressions and views of those faces. There was also a significant transfer to new faces. Benefits were maintained over a 3-month period. Training efficacy was greater for those with more perceptual deficits at baseline. We conclude that perceptual learning can lead to persistent improvements in face discrimination in acquired prosopagnosia. This reflects both acquisition of new skills that can be applied to new faces as well as a degree of overlearning of the stimulus set at the level of 3-D expression-invariant representations.
The video coding and distribution approach presented in this paper has two key characteristics that make it ideal for integration of video communication services over common broadband digital networks. The modular multi-resolution nature of the coding scheme provides the necessary flexibility to accommodate future advances in video technology as well as robust distribution over various network environments. This paper will present an efficient and scalable coding scheme for video communications. The scheme is capable of encoding and decoding video signals in a hierarchical, multilayer fashion to provide video at differing quality grades. Subsequently, the utilization of this approach to enable efficient bandwidth sharing and robust distribution of video signals in multipoint communications is presented. Coding and distribution architectures are discussed which include multi-party communications in a multi-window fashion within ATM environments. Furthermore, under the limited capabilities typical of wideband/broadband access networks, this architecture accommodates important video-based service applications such as Interactive Distance Learning.
Albert A Angehrn
Full Text Available The vast majority of knowledge management initiatives fail because they do not take sufficiently into account the emotional, psychological and social needs of individuals. Only if users see real value for themselves will they actively use and contribute their own knowledge to the system, and engage with other users. Connection dynamics can make this easier, and even enjoyable, by connecting people and bringing them closer through shared experiences such as playing a game together. A higher connectedness of people to other people, and to relevant knowledge assets, will motivate them to participate more actively and increase system usage. In this paper, we describe the design of TENTube, a video-based connection tool we are developing to support competence development. TENTube integrates rich profiling and network visualization and navigation with agent-enhanced game-like connection dynamics.
The human motion contains valuable information in many situations and people frequently perform an unconscious analysis of the motion of other people to understand their actions, intentions, and state of mind. An automatic analysis of human motion will facilitate many applications and thus has...... received great interest from both industry and research communities. The focus of this thesis is on video-based analysis of human motion and the thesis presents work within three overall topics, namely foreground segmentation, action recognition, and human pose estimation. Foreground segmentation is often...... the first important step in the analysis of human motion. By separating foreground from background the subsequent analysis can be focused and efficient. This thesis presents a robust background subtraction method that can be initialized with foreground objects in the scene and is capable of handling...
Full Text Available The flourishing of studies on the neural correlates of decision-making calls for an appraisal of the relation between perceptual decisions and conscious perception. By exploiting the long integration time of noisy motion stimuli, and by forcing human observers to make difficult speeded decisions--sometimes a blind guess--about stimulus direction, we traced the temporal buildup of motion discrimination capability and perceptual awareness, as assessed trial by trial through direct rating. We found that both increased gradually with motion coherence and viewing time, but discrimination was systematically leading awareness, reaching a plateau much earlier. Sensitivity and criterion changes contributed jointly to the slow buildup of perceptual awareness. It made no difference whether motion discrimination was accomplished by saccades or verbal responses. These findings suggest that perceptual awareness emerges on the top of a developing or even mature perceptual decision. We argue that the middle temporal (MT cortical region does not confer us the full phenomenic depth of motion perception, although it may represent a precursor stage in building our subjective sense of visual motion.
Aaron V Berard
Full Text Available Playing certain types of video games for a long time can improve a wide range of mental processes, from visual acuity to cognitive control. Frequent gamers have also displayed generalized improvements in perceptual learning. In the Texture Discrimination Task (TDT, a widely used perceptual learning paradigm, participants report the orientation of a target embedded in a field of lines and demonstrate robust over-night improvement. However, changing the orientation of the background lines midway through TDT training interferes with overnight improvements in overall performance on TDT. Interestingly, prior research has suggested that this effect will not occur if a one-hour break is allowed in between the changes. These results have suggested that after training is over, it may take some time for learning to become stabilized and resilient against interference. Here, we tested whether frequent gamers have faster stabilization of perceptual learning compared to non-gamers and examined the effect of daily video game playing on interference of training of TDT with one background orientation on perceptual learning of TDT with a different background orientation. As a result, we found that non-gamers showed overnight performance improvement only on one background orientation, replicating previous results with the interference in TDT. In contrast, frequent gamers demonstrated overnight improvements in performance with both background orientations, suggesting that they are better able to overcome interference in perceptual learning. This resistance to interference suggests that video game playing not only enhances the amplitude and speed of perceptual learning but also leads to faster and/or more robust stabilization of perceptual learning.
Berard, Aaron V.; Cain, Matthew S.; Watanabe, Takeo; Sasaki, Yuka
Playing certain types of video games for a long time can improve a wide range of mental processes, from visual acuity to cognitive control. Frequent gamers have also displayed generalized improvements in perceptual learning. In the Texture Discrimination Task (TDT), a widely used perceptual learning paradigm, participants report the orientation of a target embedded in a field of lines and demonstrate robust over-night improvement. However, changing the orientation of the background lines midway through TDT training interferes with overnight improvements in overall performance on TDT. Interestingly, prior research has suggested that this effect will not occur if a one-hour break is allowed in between the changes. These results have suggested that after training is over, it may take some time for learning to become stabilized and resilient against interference. Here, we tested whether frequent gamers have faster stabilization of perceptual learning compared to non-gamers and examined the effect of daily video game playing on interference of training of TDT with one background orientation on perceptual learning of TDT with a different background orientation. As a result, we found that non-gamers showed overnight performance improvement only on one background orientation, replicating previous results with the interference in TDT. In contrast, frequent gamers demonstrated overnight improvements in performance with both background orientations, suggesting that they are better able to overcome interference in perceptual learning. This resistance to interference suggests that video game playing not only enhances the amplitude and speed of perceptual learning but also leads to faster and/or more robust stabilization of perceptual learning. PMID:25807394
Lalonde, Kaylah; Holt, Rachael Frush
This study used the auditory evaluation framework [Erber (1982). Auditory Training (Alexander Graham Bell Association, Washington, DC)] to characterize the influence of visual speech on audiovisual (AV) speech perception in adults and children at multiple levels of perceptual processing. Six- to eight-year-old children and adults completed auditory and AV speech perception tasks at three levels of perceptual processing (detection, discrimination, and recognition). The tasks differed in the level of perceptual processing required to complete them. Adults and children demonstrated visual speech influence at all levels of perceptual processing. Whereas children demonstrated the same visual speech influence at each level of perceptual processing, adults demonstrated greater visual speech influence on tasks requiring higher levels of perceptual processing. These results support previous research demonstrating multiple mechanisms of AV speech processing (general perceptual and speech-specific mechanisms) with independent maturational time courses. The results suggest that adults rely on both general perceptual mechanisms that apply to all levels of perceptual processing and speech-specific mechanisms that apply when making phonetic decisions and/or accessing the lexicon. Six- to eight-year-old children seem to rely only on general perceptual mechanisms across levels. As expected, developmental differences in AV benefit on this and other recognition tasks likely reflect immature speech-specific mechanisms and phonetic processing in children. PMID:27106318
Full Text Available Action video game playing substantially improves visual performance; however, the source of this improvement remains unclear. Here we use the equivalent external noise technique to characterize the mechanism by which action video games may facilitate performance (Lu & Dosher, 1998. In first study, Action Video Game Players (VGPs and Non-Action Video Game Players (NVGPs performed a foveal orientation identification task at different external noise levels. VGPs showed lower thresholds than NVGPs with a marked difference at different noise levels. Perceptual Template Model fitting indicated that there were an 11% additive noise reduction and a 25% external noise exclusion. The causal effect of action video game playing was confirmed in a following 50 hour training study, This work establishes that playing action video games leads to robust internal addictive and external noise exclusion, consistent with the use of better matched perceptual templates. To investigate the discrepancy between our results and previous fovea perceptual learning research (Lu et al, 2004, same stimuli in previous experiment were used in perceptual learning experiment and we find same perceptual template improvement pattern. This suggest both action video game playing and perceptual learning could lead to better perceptual template.
Valdez, Connie A; Paulsen, Susan
To (1) describe the development of a Video-based Clinical Examination (VCE) as a formal testing format to evaluate student ability to make an accurate pharmaceutical assessment and recommendation, and (2) determine student perception of the VCE testing format. Descriptive study of first-year pharmacy students. One hundred and twenty-nine students were included in the study. Students perceived that the VCE testing format provided a real life/interactive environment but felt rushed as the video segments of the patient/pharmacist interaction occurred quickly. Based on the findings of this project, we will continue to pursue further research related to validity, reliability and application of VCEs. However, the University of Colorado will continue to incorporate VCEs in the performance based evaluations in the Professional Skills Development 1 course, as it appears to be an effective stepping-stone for first-year students to begin developing their active listening, higher level learning and problem-solving skills. Results of this project will be shared with the faculty and curriculum committee at the University of Colorado School of Pharmacy to encourage further use and research of VCEs in other courses.
Abdollahian, Golnaz; Delp, Edward J.
Although considerable work has been done in management of "structured" video such as movies, sports, and television programs that has known scene structures, "unstructured" video analysis is still a challenging problem due to its unrestricted nature. The purpose of this paper is to address issues in the analysis of unstructured video and in particular video shot by a typical unprofessional user (i.e home video). We describe how one can make use of camera motion information for unstructured video analysis. A new concept, "camera viewing direction," is introduced as the building block of home video analysis. Motion displacement vectors are employed to temporally segment the video based on this concept. We then find the correspondence between the camera behavior with respect to the subjective importance of the information in each segment and describe how different patterns in the camera motion can indicate levels of interest in a particular object or scene. By extracting these patterns, the most representative frames, keyframes, for the scenes are determined and aggregated to summarize the video sequence.
Spyrou, Evaggelos; Iakovidis, Dimitris K.
The wireless capsule endoscope is a swallowable medical device equipped with a miniature camera enabling the visual examination of the gastrointestinal (GI) tract. It wirelessly transmits thousands of images to an external video recording system, while its location and orientation are being tracked approximately by external sensor arrays. In this paper we investigate a video-based approach to tracking the capsule endoscope without requiring any external equipment. The proposed method involves extraction of speeded up robust features from video frames, registration of consecutive frames based on the random sample consensus algorithm, and estimation of the displacement and rotation of interest points within these frames. The results obtained by the application of this method on wireless capsule endoscopy videos indicate its effectiveness and improved performance over the state of the art. The findings of this research pave the way for a cost-effective localization and travel distance measurement of capsule endoscopes in the GI tract, which could contribute in the planning of more accurate surgical interventions.
Quadflieg, Norbert; Schädler, Daniela; Naab, Silke; Fichter, Manfred M
This paper presents the results of a randomized controlled trial measuring the efficacy of a video-based skills training to decrease burden and psychological distress in caregivers of inpatients treated for an eating disorder in specialized hospital units. Two hundred eighty-five caregivers were randomized to either the video intervention (N = 147) or the control group (N = 138). Caregivers' primary outcomes were assessed via Eating Disorder Symptom Impact Scale, Accommodation and Enabling Scale and General Health Questionnaire-12 at baseline and three-months follow-up. Acceptability of the intervention was high. Receiving additional external professional help like psychotherapy or clinical counselling was identified as a moderator contributing to the efficacy of the intervention. Caregivers' burden (Eating Disorder Symptom Impact Scale) and psychological distress (General Health Questionnaire-12) were reduced by the intervention but not caregivers' accommodating behaviours (Accommodation and Enabling Scale). The video training is a promising approach and effective supplement for caregivers of patients with an eating disorder. Additional professional help to caregivers increases the effectiveness of the intervention. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association.
.... Attention may affect the perceived clarity of visual displays and improve performance. In this project, a powerful external noise method was developed to identify and characterize the effect of attention on perceptual performance in visual tasks...
.... Attention may affect the perceived clarity of visual displays and improve performance. In this project, a powerful external noise method was developed to identify and characterize the effect of attention on perceptual performance in visual tasks...
Silverman, Julian; King, Catherine
Two studies employing rod-and-frame test (RFT) and a size-estimation measure of "extensiveness of scanning reported. Results indicated perceptual differentiation interpretation of RFT performance erroneous for certain kinds of Ss. (Author)
In a pioneering set of experiments, Rosch investigated the colour processing of a remote traditional culture. It was concluded that colours form universally natural and salient categories. However, our own cross-cultural research, backed up by neuropsychological data and interference studies, indicates that perceptual categories are derived from the words in the speaker's language. The new data support a rather strong version of the Whorfian view that perceptual categories are organized by the linguistic systems of our mind.
Davidoff, Jules B.
In a pioneering set of experiments, Rosch investigated the colour processing of a remote traditional culture. It was concluded that colours form universally natural and salient categories. However, our own cross-cultural research, backed up by neuropsychological data and interference studies, indicates that perceptual categories are derived from the words in the speaker's language. The new data support a rather strong version of the Whorfian view that perceptual categories are organized by th...
Rydell, Robert J; Shiffrin, Richard M; Boucher, Kathryn L; Van Loo, Katie; Rydell, Michael T
Stereotype threat (ST) refers to a situation in which a member of a group fears that her or his performance will validate an existing negative performance stereotype, causing a decrease in performance. For example, reminding women of the stereotype "women are bad at math" causes them to perform more poorly on math questions from the SAT and GRE. Performance deficits can be of several types and be produced by several mechanisms. We show that ST prevents perceptual learning, defined in our task as an increasing rate of search for a target Chinese character in a display of such characters. Displays contained two or four characters and half of these contained a target. Search rate increased across a session of training for a control group of women, but not women under ST. Speeding of search is typically explained in terms of learned "popout" (automatic attraction of attention to a target). Did women under ST learn popout but fail to express it? Following training, the women were shown two colored squares and asked to choose the one with the greater color saturation. Superimposed on the squares were task-irrelevant Chinese characters. For women not trained under ST, the presence of a trained target on one square slowed responding, indicating that training had caused the learning of an attention response to targets. Women trained under ST showed no slowing, indicating that they had not learned such an attention response.
Print-based instructional materials have been more popular than any other medium for teaching practical skills during the delivery of technical and vocational education and training via distance learning. However, the approach has its shortcomings and in recent times alternatives have been sought. The comparative instructional effectiveness of one such alternative is the focus of this paper. The study sought to examine the instructional effectiveness of video-based instructional materials vis...
Aidan Peter Murphy
Full Text Available The visual system exploits past experience at multiple timescales to resolve perceptual ambiguity in the retinal image. For example, perception of a bistable stimulus can be biased towards one interpretation over another when preceded by a brief presentation of a disambiguated version of the stimulus (positive priming or through intermittent presentations of the ambiguous stimulus (stabilization. Similarly, prior presentations of unambiguous stimuli can be used to explicitly train a long-lasting association between a percept and a retinal location (perceptual association. These phenonema have typically been regarded as independent processes, with short-term biases attributed to perceptual memory and longer-term biases described as associative learning. Here we tested for interactions between these two forms of experience-dependent perceptual bias and demonstrate that short-term processes strongly influence long-term outcomes. We first demonstrate that the establishment of long-term perceptual contingencies does not require explicit training by unambiguous stimuli, but can arise spontaneously during the periodic presentation of brief, ambiguous stimuli. Using rotating Necker cube stimuli, we observed enduring, retinotopically specific perceptual biases that were expressed from the outset and remained stable for up to forty minutes, consistent with the known phenomenon of perceptual stabilization. Further, bias was undiminished after a break period of five minutes, but was readily reset by interposed periods of continuous, as opposed to periodic, ambiguous presentation. Taken together, the results demonstrate that perceptual biases can arise naturally and may principally reflect the brain’s tendency to favor recent perceptual interpretation at a given retinal location. Further, they suggest that an association between retinal location and perceptual state, rather than a physical stimulus, is sufficient to generate long-term biases in perceptual
Full Text Available Print-based instructional materials have been more popular than any other medium for teaching practical skills during the delivery of technical and vocational education and training via distance learning. However, the approach has its shortcomings and in recent times alternatives have been sought. The comparative instructional effectiveness of one such alternative is the focus of this paper. The study sought to examine the instructional effectiveness of video-based instructional materials vis-à-vis traditional print-based instructional materials for teaching distance learners of a Block-Laying and Concreting practical skills programme. An experimental design was used and participants were randomly assigned to two treatment groups: Users of video-based instructional materials or users of print-based instructional materials. A researcher-designed performance test and an achievement test of 20 multiple-choice items were used to collect data from 34 participants who used print-based instructional materials and 35 participants who used video-based instructional materials to learn practical skills. The instruments were based on the instructional objectives of lessons on mortar and wall finish. Pilot test data for the achievement test yielded Cronbach’s alpha of 0.84. Descriptive statistics and t-test at a 0.05 level of significance were used to analyse the data. The results indicated that the two instructional materials were pedagogically equivalent in terms of theoretical knowledge acquired. Practical skills acquired, however, were significantly higher among users of video-based instructional materials. Finally, users of video-based instructional materials displayed significantly superior craftsmanship.
Andersen, Kenneth Jay; Schraefel, M. C.; Brandt, M.
Workplace interventions have shown beneficial results of resistance training for chronic pain in the neck, shoulder, and arm. However, studies have relied on experienced exercise instructors, which may not be an available resource at most workplaces. The objective of this study is to evaluate...... the technical performance level of upper limb rehabilitation exercises following video-based versus personalized exercise instruction. We recruited 38 laboratory technicians and office workers with neck/shoulder pain for a two-week exercise training period receiving either (1) personal and video or (2) video...... only instruction in four typical neck/shoulder/arm rehabilitation exercises using elastic tubing. At a 2-week follow-up, the participants' technical execution was assessed by two blinded physical therapists using a reliable error assessment tool. The error assessment was based on ordinal deviation...
Shiller, Douglas M; Rochon, Marie-Lyne
Auditory feedback plays an important role in children's speech development by providing the child with information about speech outcomes that is used to learn and fine-tune speech motor plans. The use of auditory feedback in speech motor learning has been extensively studied in adults by examining oral motor responses to manipulations of auditory feedback during speech production. Children are also capable of adapting speech motor patterns to perceived changes in auditory feedback; however, it is not known whether their capacity for motor learning is limited by immature auditory-perceptual abilities. Here, the link between speech perceptual ability and the capacity for motor learning was explored in two groups of 5- to 7-year-old children who underwent a period of auditory perceptual training followed by tests of speech motor adaptation to altered auditory feedback. One group received perceptual training on a speech acoustic property relevant to the motor task while a control group received perceptual training on an irrelevant speech contrast. Learned perceptual improvements led to an enhancement in speech motor adaptation (proportional to the perceptual change) only for the experimental group. The results indicate that children's ability to perceive relevant speech acoustic properties has a direct influence on their capacity for sensory-based speech motor adaptation.
Shiller, Douglas M.; Rochon, Marie-Lyne
Auditory feedback plays an important role in children’s speech development by providing the child with information about speech outcomes that is used to learn and fine-tune speech motor plans. The use of auditory feedback in speech motor learning has been extensively studied in adults by examining oral motor responses to manipulations of auditory feedback during speech production. Children are also capable of adapting speech motor patterns to perceived changes in auditory feedback, however it is not known whether their capacity for motor learning is limited by immature auditory-perceptual abilities. Here, the link between speech perceptual ability and the capacity for motor learning was explored in two groups of 5–7-year-old children who underwent a period of auditory perceptual training followed by tests of speech motor adaptation to altered auditory feedback. One group received perceptual training on a speech acoustic property relevant to the motor task while a control group received perceptual training on an irrelevant speech contrast. Learned perceptual improvements led to an enhancement in speech motor adaptation (proportional to the perceptual change) only for the experimental group. The results indicate that children’s ability to perceive relevant speech acoustic properties has a direct influence on their capacity for sensory-based speech motor adaptation. PMID:24842067
Full Text Available Human sensory systems allow individuals to see, hear, touch, and interact with the surrounding physical environment. Understanding human perception and its limit enables us to better exploit the psychophysics of human perceptual systems to design more efficient, adaptive algorithms and develop perceptually-inspired computational models. In this talk, I will survey some of recent efforts on perceptually-inspired computing with applications to crowd simulation and multimodal interaction. In particular, I will present data-driven personality modeling based on the results of user studies, example-guided physics-based sound synthesis using auditory perception, as well as perceptually-inspired simplification for multimodal interaction. These perceptually guided principles can be used to accelerating multi-modal interaction and visual computing, thereby creating more natural human-computer interaction and providing more immersive experiences. I will also present their use in interactive applications for entertainment, such as video games, computer animation, and shared social experience. I will conclude by discussing possible future research directions.
Hyun, Dai-Kyung; Ryu, Seung-Jin; Lee, Hae-Yeoun; Lee, Heung-Kyu
.... Nevertheless, there is little research being done on forgery of surveillance videos. This paper proposes a forensic technique to detect forgeries of surveillance video based on sensor pattern noise (SPN...
Albert, Guillaume; Renaud, Patrice; Chartier, Sylvain; Renaud, Lise; Sauvé, Louise; Bouchard, Stéphane
More and more immersive environments are developed to provide support for learning or training purposes. Ecological validity of such environments is usually based on learning performance comparisons between virtual environments and their genuine counterparts. Little is known about learning processes occurring in immersive environments. A new technique is proposed for testing perceptual learning during virtual immersion. This methodology relies upon eye-tracking technologies to analyze gaze behavior recorded in relation to virtual objects' features and tasks' requirements. It is proposed that perceptual learning mechanisms engaged could be detected through eye movements. In this study, nine subjects performed perceptual learning tasks in virtual immersion. Results obtained indicated that perceptual learning influences gaze behavior dynamics. More precisely, analysis revealed that fixation number and variability in fixation duration varied with perceptual learning level. Such findings could contribute in shedding light on learning mechanisms as well as providing additional support for validating virtual learning environments.
Michael J Proulx
Full Text Available A sensory substitution device for blind persons aims to provide the missing visual input by converting images into a form that another modality can perceive, such as sound. Here I will discuss the perceptual learning and attentional mechanisms necessary for interpreting sounds produced by a device (The vOICe in a visuospatial manner. Although some aspects of the conversion, such as relating vertical location to pitch, rely on natural crossmodal mappings, the extensive training required suggests that synthetic mappings are required to generalize perceptual learning to new objects and environments, and ultimately to experience visual qualia. Here I will discuss the effects of the conversion and training on perception and attention that demonstrate the synthetic nature of learning the crossmodal mapping. Sensorimotor experience may be required to facilitate learning, develop expertise, and to develop a form of synthetic synaesthesia.
Zyłowska, Aleksandra; Kossek, Marcin; Wawrzyniak, Małgorzata
This study is an introductory investigation of cognitive frames, focused on perceptual frames divided into information and formal perceptual frames, which were studied based on sub-additivity of frequency estimations. It was postulated that different presentations of a response scale would result in different percentage estimates of time spent watching TV or using the Internet. The results supported the existence of perceptual frames that influence the perception process and indicated that information perceptual frames had a stronger effect than formal frames. The measures made possible the exploration of the operation of perceptual frames and also outlined the relations between heuristics and cognitive frames.
Rumbach, Anna F
To determine the prevalence and nature of both acute and chronic voice problems experienced by group fitness instructors (GFIs) and gather information about the level of education currently being received by fitness professionals, the source of their education, and their opinion on mandatory voice training to highlight potential training needs. Prospective self-completion questionnaire design. A total of 361 GFIs (81 males and 280 females), aged between 18 and 67 years currently active in the Australian fitness industry completed a self-report questionnaire distributed via SurveyMonkey. The prevalence of self-reported acute and chronic voice symptoms was high at 78.95% and 70.91%, respectively. Partial voice loss and hoarseness while instructing was experienced most often (57.62%), followed by partial voice loss and hoarseness immediately after instructing (46.81%). Aphonia after teaching was less frequently reported (9.97%). Over 25% of the total cohort reported chronic voice symptoms of increased hoarseness (39.61%), difficulty with high notes (31.58%), strained voice (32.13%), and limited singing range (27.7%). Only 30% of GFIs reported having received any voice education, with even fewer respondents (10%) receiving any practical voice training, despite 98.06% agreeing that formal voice education should be covered as a standard topic in all official GFI training. The results of this study confirm that voice problems represent a significant occupational hazard for GFIs. Speech-language pathologists and other voice professionals should consider taking a proactive stance in understanding the vocal demands of the profession and engage in training for instructors to prevent both acute and chronic voice problems. Copyright © 2013 The Voice Foundation. Published by Mosby, Inc. All rights reserved.
Bele, Irene Velsvik
This study focuses on speaking voice quality in male teachers (n = 35) and male actors (n = 36), who represent untrained and trained voice users, because we wanted to investigate normal and supranormal voices. In this study, both substantial and methodologic aspects were considered. It includes a method for perceptual voice evaluation, and a basic issue was rater reliability. A listening group of 10 listeners, 7 experienced speech-language therapists, and 3 speech-language therapist students evaluated the voices by 15 vocal characteristics using VA scales. Two sets of voice signals were investigated: text reading (2 loudness levels) and sustained vowel (3 levels). The results indicated a high interrater reliability for most perceptual characteristics. Connected speech was evaluated more reliably, especially at the normal level, but both types of voice signals were evaluated reliably, although the reliability for connected speech was somewhat higher than for vowels. Experienced listeners tended to be more consistent in their ratings than did the student raters. Some vocal characteristics achieved acceptable reliability even with a smaller panel of listeners. The perceptual characteristics grouped in 4 factors reflected perceptual dimensions.
Kellman, Philip J.; Garrigan, Patrick
We consider perceptual learning: experience-induced changes in the way perceivers extract information. Often neglected in scientific accounts of learning and in instruction, perceptual learning is a fundamental contributor to human expertise and is crucial in domains where humans show remarkable levels of attainment, such as language, chess, music, and mathematics. In Section 2, we give a brief history and discuss the relation of perceptual learning to other forms of learning. We consider in Section 3 several specific phenomena, illustrating the scope and characteristics of perceptual learning, including both discovery and fluency effects. We describe abstract perceptual learning, in which structural relationships are discovered and recognized in novel instances that do not share constituent elements or basic features. In Section 4, we consider primary concepts that have been used to explain and model perceptual learning, including receptive field change, selection, and relational recoding. In Section 5, we consider the scope of perceptual learning, contrasting recent research, focused on simple sensory discriminations, with earlier work that emphasized extraction of invariance from varied instances in more complex tasks. Contrary to some recent views, we argue that perceptual learning should not be confined to changes in early sensory analyzers. Phenomena at various levels, we suggest, can be unified by models that emphasize discovery and selection of relevant information. In a final section, we consider the potential role of perceptual learning in educational settings. Most instruction emphasizes facts and procedures that can be verbalized, whereas expertise depends heavily on implicit pattern recognition and selective extraction skills acquired through perceptual learning. We consider reasons why perceptual learning has not been systematically addressed in traditional instruction, and we describe recent successful efforts to create a technology of perceptual
Lehmann, Ronny; Seitz, Anke; Bosse, Hans Martin; Lutz, Thomas; Huwendiek, Sören
Physical examination skills are crucial for a medical doctor. The physical examination of children differs significantly from that of adults. Students often have only limited contact with pediatric patients to practice these skills. In order to improve the acquisition of pediatric physical examination skills during bedside teaching, we have developed a combined video-based training concept, subsequently evaluating its use and perception. Fifteen videos were compiled, demonstrating defined physical examination sequences in children of different ages. Students were encouraged to use these videos as preparation for bedside teaching during their pediatric clerkship. After bedside teaching, acceptance of this approach was evaluated using a 10-item survey, asking for the frequency of video use and the benefits to learning, self-confidence, and preparation of bedside teaching as well as the concluding OSCE. N=175 out of 299 students returned survey forms (58.5%). Students most frequently used videos, either illustrating complete examination sequences or corresponding focus examinations frequently assessed in the OSCE. Students perceived the videos as a helpful method of conveying the practical process and preparation for bedside teaching as well as the OSCE, and altogether considered them a worthwhile learning experience. Self-confidence at bedside teaching was enhanced by preparation with the videos. The demonstration of a defined standardized procedural sequence, explanatory comments, and demonstration of infrequent procedures and findings were perceived as particularly supportive. Long video segments, poor alignment with other curricular learning activities, and technical problems were perceived as less helpful. Students prefer an optional individual use of the videos, with easy technical access, thoughtful combination with the bedside teaching, and consecutive standardized practice of demonstrated procedures. Preparation with instructional videos combined with bedside
Respiratory muscle training extends exercise tolerance without concomitant change to peak oxygen uptake: physiological, performance and perceptual responses derived from the same incremental exercise test.
Edwards, A M
There is conjecture over the efficacy of respiratory muscle training (RMT). The aim of this study was to establish whether or not exercise tolerance, physical performance and effort perceptions are influenced by RMT. Thirty-six healthy males (age 24 ± 4) agreed to participate (experimental group (EXP) n = 18, control (CON) n = 18). RMT was performed using an inspiratory pressure-threshold training device at either 55% (EXP) or 10% (CON) of maximal inspiratory effort. Measurements of spirometry and maximal static inspiratory mouth pressure were taken before and after 4 weeks of RMT in addition to an incremental test to volitional exhaustion for the determination of: (i) V˙O(2) peak; (ii) maximal velocity at volitional exhaustion (vV˙O(2) peak)); (iii) time to volitional exhaustion; and (iv) effort perceptions. There were no differences in spirometry, but mean maximal static inspiratory mouth pressure increased significantly in EXP (P incremental exercise and demonstrated a significant flattening (plateau) of V˙O(2) after training. This suggests that RMT may promote an improved performance outcome vV˙O(2) peak probably as a result of blunted afferent sensations reducing the perceived discomfort of exercise at high ventilatory loads. © 2013 The Author. Respirology © 2013 Asian Pacific Society of Respirology.
Luiz Affonso Guedes
Full Text Available Wireless sensor networks typically consist of a great number of tiny low-cost electronic devices with limited sensing and computing capabilities which cooperatively communicate to collect some kind of information from an area of interest. When wireless nodes of such networks are equipped with a low-power camera, visual data can be retrieved, facilitating a new set of novel applications. The nature of video-based wireless sensor networks demands new algorithms and solutions, since traditional wireless sensor networks approaches are not feasible or even efficient for that specialized communication scenario. The coverage problem is a crucial issue of wireless sensor networks, requiring specific solutions when video-based sensors are employed. In this paper, it is surveyed the state of the art of this particular issue, regarding strategies, algorithms and general computational solutions. Open research areas are also discussed, envisaging promising investigation considering coverage in video-based wireless sensor networks.
Costa, Daniel G; Guedes, Luiz Affonso
Wireless sensor networks typically consist of a great number of tiny low-cost electronic devices with limited sensing and computing capabilities which cooperatively communicate to collect some kind of information from an area of interest. When wireless nodes of such networks are equipped with a low-power camera, visual data can be retrieved, facilitating a new set of novel applications. The nature of video-based wireless sensor networks demands new algorithms and solutions, since traditional wireless sensor networks approaches are not feasible or even efficient for that specialized communication scenario. The coverage problem is a crucial issue of wireless sensor networks, requiring specific solutions when video-based sensors are employed. In this paper, it is surveyed the state of the art of this particular issue, regarding strategies, algorithms and general computational solutions. Open research areas are also discussed, envisaging promising investigation considering coverage in video-based wireless sensor networks.
Zhou, Peipei; Ding, Qinghai; Luo, Haibo; Hou, Xinglin
Violent interaction detection is of vital importance in some video surveillance scenarios like railway stations, prisons or psychiatric centres. Existing vision-based methods are mainly based on hand-crafted features such as statistic features between motion regions, leading to a poor adaptability to another dataset. En lightened by the development of convolutional networks on common activity recognition, we construct a FightNet to represent the complicated visual violence interaction. In this paper, a new input modality, image acceleration field is proposed to better extract the motion attributes. Firstly, each video is framed as RGB images. Secondly, optical flow field is computed using the consecutive frames and acceleration field is obtained according to the optical flow field. Thirdly, the FightNet is trained with three kinds of input modalities, i.e., RGB images for spatial networks, optical flow images and acceleration images for temporal networks. By fusing results from different inputs, we conclude whether a video tells a violent event or not. To provide researchers a common ground for comparison, we have collected a violent interaction dataset (VID), containing 2314 videos with 1077 fight ones and 1237 no-fight ones. By comparison with other algorithms, experimental results demonstrate that the proposed model for violent interaction detection shows higher accuracy and better robustness.
Barbot, Antoine; Liu, Sirui; Kimchi, Ruth; Carrasco, Marisa
Perceptual organization and selective attention are two crucial processes that influence how we perceive visual information. The former structures complex visual inputs into coherent units, whereas the later selects relevant information. Attention and perceptual organization can modulate each other, affecting visual processing and performance in various tasks and conditions. Here, we tested whether attention can alter the way multiple elements appear to be perceptually organized. We manipulated covert spatial attention using a rapid serial visual presentation task, and measured perceptual organization of two multielements arrays organized by luminance similarity as rows or columns, at both the attended and unattended locations. We found that the apparent perceptual organization of the multielement arrays is intensified when attended and attenuated when unattended. We ruled out response bias as an alternative explanation. These findings reveal that attention enhances the appearance of perceptual organization, a midlevel vision process, altering the way we perceive our visual environment.
Full Text Available Perceptual hash functions provide a tool for fast and reliable identification of content. We present new audio hash functions based on summarization of the time-frequency spectral characteristics of an audio document. The proposed hash functions are based on the periodicity series of the fundamental frequency and on singular-value description of the cepstral frequencies. They are found, on one hand, to perform very satisfactorily in identification and verification tests, and on the other hand, to be very resilient to a large variety of attacks. Moreover, we address the issue of security of hashes and propose a keying technique, and thereby a key-dependent hash function.
Bennett, Kyle D.; Aljehany, Mashal Salman; Altaf, Enas Mohammednour
Video-based instruction (VBI) has a substantial amount of research supporting its use with individuals with autism spectrum disorder and other developmental disabilities. However, it has typically been implemented as a treatment package containing multiple interventions. Additionally, there are procedural variations of VBI. Thus, it is difficult…
Golubovich, Juliya; Seybert, Jacob; Martin-Raugh, Michelle; Naemi, Bobby; Vega, Ronald P.; Roberts, Richard D.
Accurate appraisal of others' behavior is critical for the production of skilled interpersonal behavior. We used an ecologically valid methodology, a video-based situational judgment test with true-false items, to assess the accuracy with which students (N = 947) perceive the interpersonal behavior of actors involved in workplace situations.…
Bødker, Susanne; Grønbæk, Kaj; Trigg, Randal
on a fine-grained video-based analysis of a single prototyping session, and focuses on the effects of an open-ended style of interaction between users and designers around a prototype. An analysis of focus shifts, initiative and storytelling during the session is brought to bear on the question of whether...
Hada, Yoshiaki; Ogata, Hiroaki; Yano, Yoneo
This paper focuses on an online video based correction system for language learning. The prototype system using the proposed model supports learning between a native English teacher and a non-native learner using a videoconference system. It extends the videoconference system so that it can record the conversation of a learning scene. If a teacher…
This study investigated whether video-based materials can facilitate second language learners' text comprehension at the levels of macrostructure and microstructure. Three classes inclusive of 98 Chinese-speaking university students joined this study. The three classes were randomly assigned to three treatment groups: on-screen text (T Group),…
Blomqvist, Minna T.; Luhtanen, Pekka; Laakso, Lauri; Keskinen, Esko
Reports the development and validation of video-based game-understanding tests in badminton for elementary and secondary students. The tests included different sequences that simulated actual game situations. Players had to solve tactical problems by selecting appropriate solutions and arguments for their decisions. Results suggest that the test…
Martín, Estefanía; Gértrudix, Manuel; Urquiza-Fuentes, Jaime; Haya, Pablo A.
This paper describes two datasets extracted from a video-based educational experience using a social and collaborative platform. The length of the trial was 3 months. It involved 111 students from two different courses. Twenty-nine came from Computer Engineering (CE) course and 82 from Media and Communication (M&C) course. They were organised…
In the past decade, there has been important progress in the development and validation of video-based instruments that enable the systematic assessment of teaching competence with large samples of teachers, across multiple settings and populations, and by researchers other than the developers. This commentary focuses on the methodological…
Bryan, Craig J.; Dhillon-Davis, Luther E.; Dhillon-Davis, Kieran K.
In light of continuing concerns about iatrogenic effects associated with suicide prevention efforts utilizing video-based media, the impact of emotionally-charged videos on two vulnerable subgroups--suicidal viewers and suicide survivors--was explored. Following participation in routine suicide education as a part of the U.S. Air Force Suicide…
Nelson, Lee J.; Potrac, Paul; Groom, Ryan
The aim of this paper was to provide some rich insights into how an elite ice-hockey player responded to his coaches' pedagogical delivery of video-based feedback sessions. Data for this study were gathered through a series of in-depth, semi-structured interviews and a reflective log relating to those interviews. The interviews were transcribed…
Gambari, Amosa Isiaka; Yaki, Akawo Angwal; Gana, Eli S.; Ughovwa, Queen Eguono
The study examined the effects of video-based multimedia instruction on secondary school students' achievement and retention in biology. In Nigeria, 120 students (60 boys and 60 girls) were randomly selected from four secondary schools assigned either into one of three experimental groups: Animation + Narration; Animation + On-screen Text;…
Saito, Kazuya; Akiyama, Yuka
This study examined the impact of video-based conversational interaction on the longitudinal development (one academic semester) of second language production by college-level Japanese English-as-a-foreign-language learners. Students in the experimental group engaged in weekly dyadic conversation exchanges with native speakers in the United States…
Atienza, Mercedes; Cantero, Jose L; Stickgold, Robert
Perceptual learning can develop over extended periods, with slow, at times sleep-dependent, improvement seen several days after training. As a result, performance can become more automatic, that is, less dependent on voluntary attention. This study investigates whether the brain correlates of this enhancement of automaticity are sleep-dependent. Event-related potentials produced in response to complex auditory stimuli were recorded while subjects' attention was focused elsewhere. We report here that following training on an auditory discrimination task, performance continued to improve, without significant further training, for 72 hr. At the same time, several event-related potential components became evident 48-72 hr after training. Posttraining sleep deprivation prevented neither the continued performance improvement nor the slow development of cortical dynamics related to an enhanced familiarity with the task. However, those brain responses associated with the automatic shift of attention to unexpected stimuli failed to develop. Thus, in this auditory learning paradigm, posttraining sleep appears to reduce the voluntary attentional effort required for successful perceptual discrimination by facilitating the intrusion of a potentially meaningful stimulus into one's focus of attention for further evaluation.
Noëlle Junod Perron
Full Text Available Introduction: Medical students at the Faculty of Medicine, University of Geneva, Switzerland, have the opportunity to practice clinical skills with simulated patients during formative sessions in preparation for clerkships. These sessions are given in two formats: 1 direct observation of an encounter followed by verbal feedback (direct feedback and 2 subsequent review of the videotaped encounter by both student and supervisor (video-based feedback. The aim of the study was to evaluate whether content and process of feedback differed between both formats. Methods: In 2013, all second- and third-year medical students and clinical supervisors involved in formative sessions were asked to take part in the study. A sample of audiotaped feedback sessions involving supervisors who gave feedback in both formats were analyzed (content and process of the feedback using a 21-item feedback scale. Results: Forty-eight audiotaped feedback sessions involving 12 supervisors were analyzed (2 direct and 2 video-based sessions per supervisor. When adjusted for the length of feedback, there were significant differences in terms of content and process between both formats; the number of communication skills and clinical reasoning items addressed were higher in the video-based format (11.29 vs. 7.71, p=0.002 and 3.71 vs. 2.04, p=0.010, respectively. Supervisors engaged students more actively during the video-based sessions than during direct feedback sessions (self-assessment: 4.00 vs. 3.17, p=0.007; active problem-solving: 3.92 vs. 3.42, p=0.009. Students made similar observations and tended to consider that the video feedback was more useful for improving some clinical skills. Conclusion: Video-based feedback facilitates discussion of clinical reasoning, communication, and professionalism issues while at the same time actively engaging students. Different time and conceptual frameworks may explain observed differences. The choice of feedback format should depend on
Li, Jia; Xia, Changqun; Chen, Xiaowu
Image-based salient object detection (SOD) has been extensively studied in past decades. However, video-based SOD is much less explored due to the lack of large-scale video datasets within which salient objects are unambiguously defined and annotated. Toward this end, this paper proposes a video-based SOD dataset that consists of 200 videos. In constructing the dataset, we manually annotate all objects and regions over 7,650 uniformly sampled keyframes and collect the eye-tracking data of 23 subjects who free-view all videos. From the user data, we find that salient objects in a video can be defined as objects that consistently pop-out throughout the video, and objects with such attributes can be unambiguously annotated by combining manually annotated object/region masks with eye-tracking data of multiple subjects. To the best of our knowledge, it is currently the largest dataset for videobased salient object detection. Based on this dataset, this paper proposes an unsupervised baseline approach for video-based SOD by using saliencyguided stacked autoencoders. In the proposed approach, multiple spatiotemporal saliency cues are first extracted at the pixel, superpixel and object levels. With these saliency cues, stacked autoencoders are constructed in an unsupervised manner that automatically infers a saliency score for each pixel by progressively encoding the high-dimensional saliency cues gathered from the pixel and its spatiotemporal neighbors. In experiments, the proposed unsupervised approach is compared with 31 state-of-the-art models on the proposed dataset and outperforms 30 of them, including 19 imagebased classic (unsupervised or non-deep learning) models, six image-based deep learning models, and five video-based unsupervised models. Moreover, benchmarking results show that the proposed dataset is very challenging and has the potential to boost the development of video-based SOD.
Wendt, Mike; Luna-Rodriguez, Aquiles; Jacobsen, Thomas
In a variety of conflict paradigms, target and distractor stimuli are defined in terms of perceptual features. Interference evoked by distractor stimuli tends to be reduced when the ratio of congruent to incongruent trials is decreased, suggesting conflict-induced perceptual filtering (i.e., adjusting the processing weights assigned to stimuli…
Full Text Available Perceptual skills can improve dramatically even with minimal practice. A major and practical benefit of learning, however, is in transferring the improvement on the trained task to untrained tasks or stimuli, yet the mechanisms underlying this process are still poorly understood. Reduction of internal noise has been proposed as a mechanism of perceptual learning, and while we have evidence that frequency discrimination (FD learning is due to a reduction of internal noise, the source of that noise was not determined. In this study, we examined whether reducing the noise associated with neural phase locking to tones can explain the observed improvement in behavioural thresholds. We compared FD training between two tone durations (15 and 100 ms that straddled the temporal integration window of auditory nerve fibers upon which computational modeling of phase locking noise was based. Training on short tones resulted in improved FD on probe tests of both the long and short tones. Training on long tones resulted in improvement only on the long tones. Simulations of FD learning, based on the computational model and on signal detection theory, were compared with the behavioral FD data. We found that improved fidelity of phase locking accurately predicted transfer of learning from short to long tones, but also predicted transfer from long to short tones. The observed lack of transfer from long to short tones suggests the involvement of a second mechanism. Training may have increased the temporal integration window which could not transfer because integration time for the short tone is limited by its duration. Current learning models assume complex relationships between neural populations that represent the trained stimuli. In contrast, we propose that training-induced enhancement of the signal-to-noise ratio offers a parsimonious explanation of learning and transfer that easily accounts for asymmetric transfer of learning.
Huurneman, Bianca; Boonstra, F Nienke; Cox, Ralf F A; van Rens, Ger; Cillessen, Antonius H N
This study investigated whether visual perceptual learning can improve near visual acuity and reduce foveal crowding effects in four- to nine-year-old children with visual impairment. Participants were 45 children with visual impairment and 29 children with normal vision. Children with visual impairment were divided into three groups: a magnifier group (n = 12), a crowded perceptual learning group (n = 18), and an uncrowded perceptual learning group (n = 15). Children with normal vision also were divided in three groups, but were measured only at baseline. Dependent variables were single near visual acuity (NVA), crowded NVA, LH line 50% crowding NVA, number of trials, accuracy, performance time, amount of small errors, and amount of large errors. Children with visual impairment trained during six weeks, two times per week, for 30 minutes (12 training sessions). After training, children showed significant improvement of NVA in addition to specific improvements on the training task. The crowded perceptual learning group showed the largest acuity improvements (1.7 logMAR lines on the crowded chart, P visual impairment benefit from perceptual training. While task-specific improvements were observed in all training groups, transfer to crowded NVA was largest in the crowded perceptual learning group. To our knowledge, this is the first study to provide evidence for the improvement of NVA by perceptual learning in children with visual impairment. (http://www.trialregister.nl number, NTR2537.).
Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.
This instructor's guide contains the materials required to teach four competency-based course units of instruction in installing compressed natural gas (CNG) systems in motor vehicles. It is designed to accompany an instructional videotape (not included) on CNG installation. The following competencies are covered in the four instructional units:…
Leonardo A. Mercado
Full Text Available In this paper, we explore the benefits to teacher evaluation when video-based self-observation is done by teachers as a vehicle for individual, reflective practice. We explore how it was applied systematically at the Instituto Cultural Peruano Norteamericano (ICPNA bi-national center in Lima, Peru among hundreds of English as a foreign language (EFL teachers in two institution-wide initiatives that have relied on self-observation through video professional development. In these cases, we provide a descriptive framework for each initiative as well as information on what was ultimately achieved by teachers, supervisors and the institution as a whole. We conclude with recommendations for implementing video-based self-evaluation.
AKINCI, Gökay; Polat, Ediz; Koçak, Orhan Murat
Eye pupil detection systems have become increasingly popular in image processing and computer vision applications in medical systems. In this study, a video-based eye pupil detection system is developed for diagnosing bipolar disorder. Bipolar disorder is a condition in which people experience changes in cognitive processes and abilities, including reduced attentional and executive capabilities and impaired memory. In order to detect these abnormal behaviors, a number of neuropsychologi...
Mota, Paulo; Carvalho, Nuno; Carvalho-Dias, Emanuel; João Costa, Manuel; Correia-Pinto, Jorge; Lima, Estevão
Since the end of the XIX century, teaching of surgery has remained practically unaltered until now. With the dawn of video-assisted laparoscopy, surgery has faced new technical and learning challenges. Due to technological advances, from Internet access to portable electronic devices, the use of online resources is part of the educational armamentarium. In this respect, videos have already proven to be effective and useful, however the best way to benefit from these tools is still not clearly defined. To assess the importance of video-based learning, using an electronic questionnaire applied to residents and specialists of different surgical fields. Importance of video-based learning was assessed in a sample of 141 subjects, using a questionnaire distributed by a GoogleDoc online form. We found that 98.6% of the respondents have already used videos to prepare for surgery. When comparing video sources by formation status, residents were found to use Youtube significantly more often than specialists (p didactic illustrations and procedure narration than specialists (p < 0.001). On the other hand, specialists prized surgeon's technical skill and the presence of tips and tricks much more than residents (p < 0.001). Video-based learning is currently a hallmark of surgical preparation among residents and specialists working in Portugal. Based on these findings we believe that the creation of quality and scientifically accurate videos, and subsequent compilation in available video-libraries appears to be the future landscape for video-based learning. Copyright © 2017 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.
Huang, Zhiwu; Shan, Shiguang; Wang, Ruiping; Zhang, Haihong; Lao, Shihong; Kuerban, Alifu; Chen, Xilin
Face recognition with still face images has been widely studied, while the research on video-based face recognition is inadequate relatively, especially in terms of benchmark datasets and comparisons. Real-world video-based face recognition applications require techniques for three distinct scenarios: 1) Videoto-Still (V2S); 2) Still-to-Video (S2V); and 3) Video-to-Video (V2V), respectively, taking video or still image as query or target. To the best of our knowledge, few datasets and evaluation protocols have benchmarked for all the three scenarios. In order to facilitate the study of this specific topic, this paper contributes a benchmarking and comparative study based on a newly collected still/video face database, named COX(1) Face DB. Specifically, we make three contributions. First, we collect and release a largescale still/video face database to simulate video surveillance with three different video-based face recognition scenarios (i.e., V2S, S2V, and V2V). Second, for benchmarking the three scenarios designed on our database, we review and experimentally compare a number of existing set-based methods. Third, we further propose a novel Point-to-Set Correlation Learning (PSCL) method, and experimentally show that it can be used as a promising baseline method for V2S/S2V face recognition on COX Face DB. Extensive experimental results clearly demonstrate that video-based face recognition needs more efforts, and our COX Face DB is a good benchmark database for evaluation.
Liu, Hao; Lu, Jiwen; Feng, Jianjiang; Zhou, Jie
In this paper, we propose a two-stream transformer networks (TSTN) approach for video-based face alignment. Unlike conventional image-based face alignment approaches which cannot explicitly model the temporal dependency in videos and motivated by the fact that consistent movements of facial landmarks usually occur across consecutive frames, our TSTN aims to capture the complementary information of both the spatial appearance on still frames and the temporal consistency information across frames. To achieve this, we develop a two-stream architecture, which decomposes the video-based face alignment into spatial and temporal streams accordingly. Specifically, the spatial stream aims to transform the facial image to the landmark positions by preserving the holistic facial shape structure. Accordingly, the temporal stream encodes the video input as active appearance codes, where the temporal consistency information across frames is captured to help shape refinements. Experimental results on the benchmarking video-based face alignment datasets show very competitive performance of our method in comparisons to the state-of-the-arts.
Amitay, Sygal; Halliday, Lorna; Taylor, Jenny; Sohoglu, Ediz; Moore, David R
Although feedback on performance is generally thought to promote perceptual learning, the role and necessity of feedback remain unclear. We investigated the effect of providing varying amounts of positive feedback while listeners attempted to discriminate between three identical tones on learning frequency discrimination. Using this novel procedure, the feedback was meaningless and random in relation to the listeners' responses, but the amount of feedback provided (or lack thereof) affected learning. We found that a group of listeners who received positive feedback on 10% of the trials improved their performance on the task (learned), while other groups provided either with excess (90%) or with no feedback did not learn. Superimposed on these group data, however, individual listeners showed other systematic changes of performance. In particular, those with lower non-verbal IQ who trained in the no feedback condition performed more poorly after training. This pattern of results cannot be accounted for by learning models that ascribe an external teacher role to feedback. We suggest, instead, that feedback is used to monitor performance on the task in relation to its perceived difficulty, and that listeners who learn without the benefit of feedback are adept at self-monitoring of performance, a trait that also supports better performance on non-verbal IQ tests. These results show that 'perceptual' learning is strongly influenced by top-down processes of motivation and intelligence.
Full Text Available BACKGROUND: Although feedback on performance is generally thought to promote perceptual learning, the role and necessity of feedback remain unclear. We investigated the effect of providing varying amounts of positive feedback while listeners attempted to discriminate between three identical tones on learning frequency discrimination. METHODOLOGY/PRINCIPAL FINDINGS: Using this novel procedure, the feedback was meaningless and random in relation to the listeners' responses, but the amount of feedback provided (or lack thereof affected learning. We found that a group of listeners who received positive feedback on 10% of the trials improved their performance on the task (learned, while other groups provided either with excess (90% or with no feedback did not learn. Superimposed on these group data, however, individual listeners showed other systematic changes of performance. In particular, those with lower non-verbal IQ who trained in the no feedback condition performed more poorly after training. CONCLUSIONS/SIGNIFICANCE: This pattern of results cannot be accounted for by learning models that ascribe an external teacher role to feedback. We suggest, instead, that feedback is used to monitor performance on the task in relation to its perceived difficulty, and that listeners who learn without the benefit of feedback are adept at self-monitoring of performance, a trait that also supports better performance on non-verbal IQ tests. These results show that 'perceptual' learning is strongly influenced by top-down processes of motivation and intelligence.
Bejjanki, Vikranth R.; Beck, Jeffrey M.; Lu, Zhong-Lin; Pouget, Alexandre
Extensive training on simple tasks like fine orientation discrimination results in large improvements in performance, a form of learning known as perceptual learning. Previous neural models have argued that perceptual learning is the result of sharpening and amplification of tuning curves in early visual areas. However, these models are at odds with the conclusions of psychophysical experiments manipulating external noise, which argue for improved decision making, presumably in later visual areas. Here, we explore the possibility that perceptual learning for fine orientation discrimination is due to improved probabilistic inference in early visual areas. We show that this mechanism captures both the changes in response properties observed in early visual areas and the changes in performance observed in psychophysical experiments. We also suggest that sharpening and amplification of tuning curves may play only a minor role in improving performance, in comparison to the role played by the reshaping of inter-neuronal correlations. PMID:21460833
Han, Xiaoguang; Fu, Hongbo; Zheng, Hanlin; Liu, Ligang; Wang, Jue
Stop-motion is a well-established animation technique but is often laborious and requires craft skills. A new video-based system can animate the vast majority of everyday objects in stop-motion style, more flexibly and intuitively. Animators can perform and capture motions continuously instead of breaking them into increments and shooting one still picture per increment. More important, the system permits direct hand manipulation without resorting to rigs, achieving more natural object control for beginners. The system's key component is two-phase keyframe-based capturing and processing, assisted by computer vision techniques. With this system, even amateurs can generate high-quality stop-motion animations.
Full Text Available Research of visual perceptual learning has illuminated the flexibility of processing in the visual system and provides insights into therapeutic approaches to remediating some components of low vision. A key observation from research of perceptual learning is that effects of training are often highly specific to the attributes of the trained stimuli. This observation has been a blessing to basic research, providing important constraints to models of learning, but is a curse to translational research, which has the goal of creating therapies that generalize widely across visual tasks and stimuli. Here we suggest that the curse of specificity can be overcome by adopting a different experimental framework than is standard in the field. Namely, translational studies should integrate many approaches together and sacrifice mechanistic understanding to gain clinical relevance. To validate this argument, we review research from our lab and others, and also present new data, that together shows how perceptual learning on basic stimuli can lead to improvements on standard vision tests as well as real world vision use such as improved reading and even improved sports performance. Furthermore, we show evidence that this integrative approach to perceptual learning can ameliorate effects of presbyopia and provides promise to improve visual function for individuals suffering from low vision.
Skewes, Joshua C; Jegindø, Else-Marie; Gebauer, Line
Autistic people are better at perceiving details. Major theories explain this in terms of bottom-up sensory mechanisms or in terms of top-down cognitive biases. Recently, it has become possible to link these theories within a common framework. This framework assumes that perception is implicit neural inference, combining sensory evidence with prior perceptual knowledge. Within this framework, perceptual differences may occur because of enhanced precision in how sensory evidence is represented or because sensory evidence is weighted much higher than prior perceptual knowledge. In this preliminary study, we compared these models using groups with high and low autistic trait scores (Autism-Spectrum Quotient). We found evidence supporting the cognitive bias model and no evidence for the enhanced sensory precision model. © The Author(s) 2014.
Green, C Shawn; Li, Renjie; Bavelier, Daphne
Action video games have been shown to enhance behavioral performance on a wide variety of perceptual tasks, from those that require effective allocation of attentional resources across the visual scene, to those that demand the successful identification of fleetingly presented stimuli. Importantly, these effects have not only been shown in expert action video game players, but a causative link has been established between action video game play and enhanced processing through training studies. Although an account based solely on attention fails to capture the variety of enhancements observed after action game playing, a number of models of perceptual learning are consistent with the observed results, with behavioral modeling favoring the hypothesis that avid video game players are better able to form templates for, or extract the relevant statistics of, the task at hand. This may suggest that the neural site of learning is in areas where information is integrated and actions are selected; yet changes in low-level sensory areas cannot be ruled out. Copyright © 2009 Cognitive Science Society, Inc.
Tsodyks, Misha; Gilbert, Charles
Sensory perception is a learned trait. The brain strategies we use to perceive the world are constantly modified by experience. With practice, we subconsciously become better at identifying familiar objects or distinguishing fine details in our environment. Current theoretical models simulate some properties of perceptual learning, but neglect the underlying cortical circuits. Future neural network models must incorporate the top-down alteration of cortical function by expectation or perceptual tasks. These newly found dynamic processes are challenging earlier views of static and feedforward processing of sensory information. PMID:15483598
Barton, Robert; Lemley, Corey; French, Paul
Recent advancements in computing technology have drastically improved the interface between computers and video equipment, thus allowing for the improvement of video-based motion analysis. However, analysis of video data remains susceptible to errors caused by lens distortion, angular distortion, descaling, and discretization. In previous work, methods were developed to correct for some of these errors. This paper presents several improvements to these corrections, as well as additional methods to increase accuracy, including: 1) improvement of the measurement of lens distortion, 2) automation of the lens distortion correction technique, 3) a simulation method to test the correction of lens distortion error, 4) creation of an algorithm to correct for angular distortion, and 5) refinement of a two camera system to correct for descaling error. The methods were tested in the context of the measurement of the air resistance force on a high-speed projectile. This allowed for the determination of the onset of turbulent flow. These significant improvements in accuracy have made video-based analysis an even more powerful tool for the study of motion.
Bulan, Orhan; Loce, Robert P.; Wu, Wencheng; Wang, YaoRong; Bernal, Edgar A.; Fan, Zhigang
Urban parking management is receiving significant attention due to its potential to reduce traffic congestion, fuel consumption, and emissions. Real-time parking occupancy detection is a critical component of on-street parking management systems, where occupancy information is relayed to drivers via smart phone apps, radio, Internet, on-road signs, or global positioning system auxiliary signals. Video-based parking occupancy detection systems can provide a cost-effective solution to the sensing task while providing additional functionality for traffic law enforcement and surveillance. We present a video-based on-street parking occupancy detection system that can operate in real time. Our system accounts for the inherent challenges that exist in on-street parking settings, including illumination changes, rain, shadows, occlusions, and camera motion. Our method utilizes several components from video processing and computer vision for motion detection, background subtraction, and vehicle detection. We also present three traffic law enforcement applications: parking angle violation detection, parking boundary violation detection, and exclusion zone violation detection, which can be integrated into the parking occupancy cameras as a value-added option. Our experimental results show that the proposed parking occupancy detection method performs in real-time at 5 frames/s and achieves better than 90% detection accuracy across several days of videos captured in a busy street block under various weather conditions such as sunny, cloudy, and rainy, among others.
Full Text Available Objective The purpose of this paper is to describe the use of video-based observation research methods in primary care environment and highlight important methodological considerations and provide practical guidance for primary care and human factors researchers conducting video studies to understand patient–clinician interaction in primary care settings.Methods We reviewed studies in the literature which used video methods in health care research, and we also used our own experience based on the video studies we conducted in primary care settings.Results This paper highlighted the benefits of using video techniques, such as multi-channel recording and video coding, and compared “unmanned” video recording with the traditional observation method in primary care research. We proposed a list that can be followed step by step to conduct an effective video study in a primary care setting for a given problem. This paper also described obstacles, researchers should anticipate when using video recording methods in future studies.Conclusion With the new technological improvements, video-based observation research is becoming a promising method in primary care and HFE research. Video recording has been under-utilised as a data collection tool because of confidentiality and privacy issues. However, it has many benefits as opposed to traditional observations, and recent studies using video recording methods have introduced new research areas and approaches.
Full Text Available In this paper, we suggest that case-based resources, which are used for assisting cognition during problem solving, can be structured around the work of narratives in social cultural psychology. Theories and other research methods have proposed structures within narratives and stories which may be useful to the design of case-based resources. Moreover, embedded within cases are stories which are contextually rich, supporting the epistemological groundings of situated cognition. Therefore the purposes of this paper are to discuss possible frameworks of case-stories; derive design principles as to what constitutes a good case story or narrative; and suggest how technology can support story-based learning. We adopt video-based Computer-Supported Collaborative Learning (CSCL technology to support problem solving with case-stories learning scenarios. Our hypothesis in this paper is that well-designed case-based resources are able to aid in the cognitive processes undergirding problem solving and meaning making. We also suggest the use of an emerging video-based collaborative learning technology to support such an instructional strategy.
Full Text Available The study aims at developing and exploring a novel video-based assessment that captures classroom management expertise (CME of teachers and for which statistical results are provided. CME measurement is conceptualized by using four video clips that refer to typical classroom management situations in which teachers are heavily challenged (involving the challenges to manage transitions, instructional time, student behavior, and instructional feedback and by applying three cognitive demands posed on respondents when responding to test items related to the video clips (accuracy of perception, holistic perception, and justification of action. Research questions are raised regarding reliability, testlet effects (related to the four video clips applied for measurement, intercorrelations of cognitive demands, and criterion-related validity of the instrument. Evidence is provided that (1 using a video-based assessment CME can be measured in a reliable way, (2 the CME total score represents a general ability that is only slightly influenced by testlet effects related to the four video clips, (3 the three cognitive demands conceptualized for the measurement of CME are highly intercorrelated, and (4 the CME measure is positively correlated with declarative-conceptual general pedagogical knowledge (medium effect size, whereas it shows only small size correlations with non-cognitive teacher variables.
Asan, Onur; Montague, Enid
The purpose of this paper is to describe the use of video-based observation research methods in primary care environment and highlight important methodological considerations and provide practical guidance for primary care and human factors researchers conducting video studies to understand patient-clinician interaction in primary care settings. We reviewed studies in the literature which used video methods in health care research, and we also used our own experience based on the video studies we conducted in primary care settings. This paper highlighted the benefits of using video techniques, such as multi-channel recording and video coding, and compared "unmanned" video recording with the traditional observation method in primary care research. We proposed a list that can be followed step by step to conduct an effective video study in a primary care setting for a given problem. This paper also described obstacles, researchers should anticipate when using video recording methods in future studies. With the new technological improvements, video-based observation research is becoming a promising method in primary care and HFE research. Video recording has been under-utilised as a data collection tool because of confidentiality and privacy issues. However, it has many benefits as opposed to traditional observations, and recent studies using video recording methods have introduced new research areas and approaches.
Xi, Jie; Jia, Wu-Li; Feng, Li-Xia; Lu, Zhong-Lin; Huang, Chang-Bing
Amblyopia is a developmental disorder that results in both monocular and binocular deficits. Although traditional treatment in clinical practice (i.e., refractive correction, or occlusion by patching and penalization of the fellow eye) is effective in restoring monocular visual acuity, there is little information on how binocular function, especially stereopsis, responds to traditional amblyopia treatment. We aim to evaluate the effects of perceptual learning on stereopsis in observers with amblyopia in the current study. Eleven observers (21.1 ± 5.1 years, six females) with anisometropic or ametropic amblyopia were trained to judge depth in 10 to 13 sessions. Red-green glasses were used to present three different texture anaglyphs with different disparities but a fixed exposure duration. Stereoacuity was assessed with the Fly Stereo Acuity Test and visual acuity was assessed with the Chinese Tumbling E Chart before and after training. Averaged across observers, training significantly reduced disparity threshold from 776.7″ to 490.4″ (P amblyopia. These results, together with previous evidence, suggest that structured monocular and binocular training might be necessary to fully recover degraded visual functions in amblyopia. Chinese Abstract.
Grzeczkowski, Lukasz; Cretenoud, Aline; Herzog, Michael H; Mast, Fred W
Perceptual learning is usually assumed to occur within sensory areas or when sensory evidence is mapped onto decisions. Subsequent procedural and motor processes, involved in most perceptual learning experiments, are thought to play no role in the learning process. Here, we show that this is not the case. Observers trained with a standard three-line bisection task and indicated the offset direction of the central line by pressing either a left or right push button. Before and after training, observers adjusted the central line of the same bisection stimulus using a computer mouse. As expected, performance improved through training. Surprisingly, learning did not transfer to the untrained mouse adjustment condition. The same was true for the opposite, i.e., training with mouse adjustments did not transfer to the push button condition. We found partial transfer when observers adjusted the central line with two different adjustment procedures. We suggest that perceptual learning is specific to procedural motor aspects beyond visual processing. Our results support theories were visual stimuli are coded together with their corresponding actions.
de Kok, I.A.; Poppe, Ronald Walter; Heylen, Dirk K.J.
We introduce Iterative Perceptual Learning (IPL), a novel approach for learning computational models for social behavior synthesis from corpora of human-human interactions. The IPL approach combines perceptual evaluation with iterative model refinement. Human observers rate the appropriateness of
de Kok, I.A.; Poppe, Ronald Walter; Heylen, Dirk K.J.
We introduce Iterative Perceptual Learning (IPL), a novel approach to learn computational models for social behavior synthesis from corpora of human–human interactions. IPL combines perceptual evaluation with iterative model refinement. Human observers rate the appropriateness of synthesized
Huurneman, Bianca; Boonstra, F Nienke; Goossens, Jeroen
To identify predictors of sensitivity to perceptual learning on a computerized, near-threshold letter discrimination task in children with infantile nystagmus (idiopathic IN: n = 18; oculocutaneous albinism accompanied by IN: n = 18). Children were divided into two age-, acuity-, and diagnosis-matched training groups: a crowded (n = 18) and an uncrowded training group (n = 18). Training consisted of 10 sessions spread out over 5 weeks (grand total of 3500 trials). Baseline performance, age, diagnosis, training condition, and perceived pleasantness of training (training joy) were entered as linear regression predictors of training-induced changes on a single- and a crowded-letter task. An impressive 57% of the variability in improvements of single-letter visual acuity was explained by age, training condition, and training joy. Being older and training with uncrowded letters were associated with larger single-letter visual acuity improvements. More training joy was associated with a larger gain from the uncrowded training and a smaller gain from the crowded training. Fifty-six percent of the variability in crowded-letter task improvements was explained by baseline performance, age, diagnosis, and training condition. After regressing out the variability induced by training condition, baseline performance, and age, perceptual learning proved more effective for children with idiopathic IN than for children with albinism accompanied by IN. Training gains increased with poorer baseline performance in idiopaths, but not in children with albinism accompanied by IN. Age and baseline performance, but not training joy, are important prognostic factors for the effect of perceptual learning in children with IN. However, their predictive value for achieving improvements in single-letter acuity and crowded letter acuity, respectively, differs between diagnostic subgroups and training condition. These findings may help with personalized treatment of individuals likely to benefit
Kawabe, Takahiro; Maruya, Kazushi; Nishida, Shin’ya
Human vision has a remarkable ability to perceive two layers at the same retinal locations, a transparent layer in front of a background surface. Critical image cues to perceptual transparency, studied extensively in the past, are changes in luminance or color that could be caused by light absorptions and reflections by the front layer, but such image changes may not be clearly visible when the front layer consists of a pure transparent material such as water. Our daily experiences with transparent materials of this kind suggest that an alternative potential cue of visual transparency is image deformations of a background pattern caused by light refraction. Although previous studies have indicated that these image deformations, at least static ones, play little role in perceptual transparency, here we show that dynamic image deformations of the background pattern, which could be produced by light refraction on a moving liquid’s surface, can produce a vivid impression of a transparent liquid layer without the aid of any other visual cues as to the presence of a transparent layer. Furthermore, a transparent liquid layer perceptually emerges even from a randomly generated dynamic image deformation as long as it is similar to real liquid deformations in its spatiotemporal frequency profile. Our findings indicate that the brain can perceptually infer the presence of “invisible” transparent liquids by analyzing the spatiotemporal structure of dynamic image deformation, for which it uses a relatively simple computation that does not require high-level knowledge about the detailed physics of liquid deformation. PMID:26240313
Kellman, Philip J.; Massey, Christine M.
Recent research indicates that perceptual learning (PL)--experience-induced changes in the way perceivers extract information--plays a larger role in complex cognitive tasks, including abstract and symbolic domains, than has been understood in theory or implemented in instruction. Here, we describe the involvement of PL in complex cognitive tasks…
Hsieh, Po-Jang; Colas, Jaron T.
A retinally stabilized object readily undergoes perceptual fading and disappears from consciousness. This startling phenomenon is commonly believed to arise from local bottom-up sensory adaptation to edge information that occurs early in the visual pathway, such as in the lateral geniculate nucleus of the thalamus or retinal ganglion cells. Here…
Trzcinski, Natalie K; Gomez-Ramirez, Manuel; Hsiao, Steven S.
Continuous training enhances perceptual discrimination and promotes neural changes in areas encoding the experienced stimuli. This type of experience-dependent plasticity has been demonstrated in several sensory and motor systems. Particularly, non-human primates trained to detect consecutive tactile bar indentations across multiple digits showed expanded excitatory receptive fields (RFs) in somatosensory cortex. However, the perceptual implications of these anatomical changes remain undetermined. Here, we trained human participants for nine days on a tactile task that promoted expansion of multi-digit RFs. Participants were required to detect consecutive indentations of bar stimuli spanning multiple digits. Throughout the training regime we tracked participants’ discrimination thresholds on spatial (grating orientation) and temporal tasks on the trained and untrained hands in separate sessions. We hypothesized that training on the multi-digit task would decrease perceptual thresholds on tasks that require stimulus processing across multiple digits, while also increasing thresholds on tasks requiring discrimination on single digits. We observed an increase in orientation thresholds on a single-digit. Importantly, this effect was selective for the stimulus orientation and hand used during multi-digit training. We also found that temporal acuity between digits improved across trained digits, suggesting that discriminating the temporal order of multi-digit stimuli can transfer to temporal discrimination of other tactile stimuli. These results suggest that experience-dependent plasticity following perceptual learning improves and interferes with tactile abilities in manners predictive of the task and stimulus features used during training. PMID:27422224
Aggarwal, R.; Grantcharov, T.; Moorthy, K.
Objective: To determine the feasibility, validity, inter-rater, and intertest reliability of 4 previously published video-based rating scales, for technical skills assessment on a benchmark laparoscopic procedure. Summary Background Data: Assessment of technical skills is crucial to the demonstra......Objective: To determine the feasibility, validity, inter-rater, and intertest reliability of 4 previously published video-based rating scales, for technical skills assessment on a benchmark laparoscopic procedure. Summary Background Data: Assessment of technical skills is crucial...... patients within 2 Academic Surgical Departments. All patients had a diagnosis of biliary colic. Surgical technical skills were rated posthoc in a blinded manner by 2 experienced observers on 4 video-based rating scales. The different scales used had been developed to assess generic or procedure...
Wang, Qia; Lobzhanidze, Alex; Jang, Hyun; Zeng, Wenjun; Shang, Yi; Yang, Jingyu
Smartphones are becoming popular nowadays not only because of its communication functionality but also, more importantly, its powerful sensing and computing capability. In this paper, we describe a novel and accurate image and video based remote target localization and tracking system using the Android smartphones, by leveraging its built-in sensors such as camera, digital compass, GPS, etc. Even though many other distance estimation or localization devices are available, our all-in-one, easy-to-use localization and tracking system on low cost and commodity smartphones is first of its kind. Furthermore, smartphones' exclusive user-friendly interface has been effectively taken advantage of by our system to facilitate low complexity and high accuracy. Our experimental results show that our system works accurately and efficiently.
Wu, Pei-Hsun; Agarwal, Ashutosh; Hess, Henry; Khargonekar, Pramod P.; Tseng, Yiider
Abstract The fidelity of the trajectories obtained from video-based particle tracking determines the success of a variety of biophysical techniques, including in situ single cell particle tracking and in vitro motility assays. However, the image acquisition process is complicated by system noise, which causes positioning error in the trajectories derived from image analysis. Here, we explore the possibility of reducing the positioning error by the application of a Kalman filter, a powerful algorithm to estimate the state of a linear dynamic system from noisy measurements. We show that the optimal Kalman filter parameters can be determined in an appropriate experimental setting, and that the Kalman filter can markedly reduce the positioning error while retaining the intrinsic fluctuations of the dynamic process. We believe the Kalman filter can potentially serve as a powerful tool to infer a trajectory of ultra-high fidelity from noisy images, revealing the details of dynamic cellular processes. PMID:20550894
Full Text Available This paper presents a parallel TBB-CUDA implementation for the acceleration of single-Gaussian distribution model, which is effective for background removal in the video-based fire detection system. In this framework, TBB mainly deals with initializing work of the estimated Gaussian model running on CPU, and CUDA performs background removal and adaption of the model running on GPU. This implementation can exploit the combined computation power of TBB-CUDA, which can be applied to the real-time environment. Over 220 video sequences are utilized in the experiments. The experimental results illustrate that TBB+CUDA can achieve a higher speedup than both TBB and CUDA. The proposed framework can effectively overcome the disadvantages of limited memory bandwidth and few execution units of CPU, and it reduces data transfer latency and memory latency between CPU and GPU.
Wang, Jiayun; Zu, Jian; Wang, Likang
In this paper, considering the atmospheric refractive index, we present an approach to extract the recording date and geo-location from videos, based on the alteration of the shadow length. The paper carefully takes different information (photographed date, the length of the selected object) of the given video into consideration and forms a comprehensive approach to extract the temporal and spatial information of the given video. On the basis of this approach, we analyze the shadow length data of a chosen object from a real video and extract the temporal and spatial information of the video. Compared with the actual information, the error is less than 1%, which proves the validity of our approach.
Dinse, Hubert R; Kattenstroth, J C; Lenz, M; Tegenthoff, M; Wolf, O T
Cortisol, the primary glucocorticoid (GC) in humans, influences neuronal excitability and plasticity by acting on mineralocorticoid and glucocorticoid receptors. Cellular studies demonstrated that elevated GC levels affect neuronal plasticity, for example through a reduction of hippocampal long-term potentiation (LTP). At the behavioural level, after treatment with GCs, numerous studies have reported impaired hippocampal function, such as impaired memory retrieval. In contrast, relatively little is known about the impact of GCs on cortical plasticity and perceptual learning in adult humans. Therefore, in this study, we explored the impact of elevated GC levels on human perceptual learning. To this aim, we used a training-independent learning approach, where lasting changes in human perception can be induced by applying passive repetitive sensory stimulation (rss), the timing of which was determined from cellular LTP studies. In our placebo-controlled double-blind study, we used tactile LTP-like stimulation to induce improvements in tactile acuity (spatial two-point discrimination). Our results show that a single administration of hydrocortisone (30mg) completely blocked rss-induced changes in two-point discrimination. In contrast, the placebo group showed the expected rss-induced increase in two-point discrimination of over 14%. Our data demonstrate that high GC levels inhibit rss-induced perceptual learning. We suggest that the suppression of LTP, as previously reported in cellular studies, may explain the perceptual learning impairments observed here. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.
Full Text Available The primary visual cortex (V1 is pre-wired to facilitate the extraction of behaviorally important visual features. Collinear edge detectors in V1, for instance, mutually enhance each other to improve the perception of lines against a noisy background. The same pre-wiring that facilitates line extraction, however, is detrimental when subjects have to discriminate the brightness of different line segments. How is it possible to improve in one task by unsupervised practicing, without getting worse in the other task? The classical view of perceptual learning is that practicing modulates the feedforward input stream through synaptic modifications onto or within V1. However, any rewiring of V1 would deteriorate other perceptual abilities different from the trained one. We propose a general neuronal model showing that perceptual learning can modulate top-down input to V1 in a task-specific way while feedforward and lateral pathways remain intact. Consistent with biological data, the model explains how context-dependent brightness discrimination is improved by a top-down recruitment of recurrent inhibition and a top-down induced increase of the neuronal gain within V1. Both the top-down modulation of inhibition and of neuronal gain are suggested to be universal features of cortical microcircuits which enable perceptual learning.
Full Text Available Color camera characterization, mapping outputs from the camera sensors to an independent color space, such as \\(XYZ\\, is an important step in the camera processing pipeline. Until now, this procedure has been primarily solved by using a \\(3 \\times 3\\ matrix obtained via a least-squares optimization. In this paper, we propose to use the spherical sampling method, recently published by Finlayson al., to perform a perceptual color characterization. In particular, we search for the \\(3 \\times 3\\ matrix that minimizes three different perceptual errors, one pixel based and two spatially based. For the pixel-based case, we minimize the CIE \\(\\Delta E\\ error, while for the spatial-based case, we minimize both the S-CIELAB error and the CID error measure. Our results demonstrate an improvement of approximately 3for the \\(\\Delta E\\ error, 7& for the S-CIELAB error and 13% for the CID error measures.
Lenay, Charles; Stewart, John
WORK AIMED AT STUDYING SOCIAL COGNITION IN AN INTERACTIONIST PERSPECTIVE OFTEN ENCOUNTERS SUBSTANTIAL THEORETICAL AND METHODOLOGICAL DIFFICULTIES: identifying the significant behavioral variables; recording them without disturbing the interaction; and distinguishing between: (a) the necessary and sufficient contributions of each individual partner for a collective dynamics to emerge; (b) features which derive from this collective dynamics and escape from the control of the individual partners; and (c) the phenomena arising from this collective dynamics which are subsequently appropriated and used by the partners. We propose a minimalist experimental paradigm as a basis for this conceptual discussion: by reducing the sensory inputs to a strict minimum, we force a spatial and temporal deployment of the perceptual activities, which makes it possible to obtain a complete recording and control of the dynamics of interaction. After presenting the principles of this minimalist approach to perception, we describe a series of experiments on two major questions in social cognition: recognizing the presence of another intentional subject; and phenomena of imitation. In both cases, we propose explanatory schema which render an interactionist approach to social cognition clear and explicit. Starting from our earlier work on perceptual crossing we present a new experiment on the mechanisms of reciprocal recognition of the perceptual intentionality of the other subject: the emergent collective dynamics of the perceptual crossing can be appropriated by each subject. We then present an experimental study of opaque imitation (when the subjects cannot see what they themselves are doing). This study makes it possible to characterize what a properly interactionist approach to imitation might be. In conclusion, we draw on these results, to show how an interactionist approach can contribute to a fully social approach to social cognition.
Zhang, Jun-Yun; Cong, Lin-Juan; Klein, Stanley A; Levi, Dennis M; Yu, Cong
We investigated whether perceptual learning in adults with amblyopia could be enabled to transfer completely to an orthogonal orientation, which would suggest that amblyopic perceptual learning results mainly from high-level cognitive compensation, rather than plasticity in the amblyopic early visual brain. Nineteen adults (mean age = 22.5 years) with anisometropic and/or strabismic amblyopia were trained following a training-plus-exposure (TPE) protocol. The amblyopic eyes practiced contrast, orientation, or Vernier discrimination at one orientation for six to eight sessions. Then the amblyopic or nonamblyopic eyes were exposed to an orthogonal orientation via practicing an irrelevant task. Training was first performed at a lower spatial frequency (SF), then at a higher SF near the cutoff frequency of the amblyopic eye. Perceptual learning was initially orientation specific. However, after exposure to the orthogonal orientation, learning transferred to an orthogonal orientation completely. Reversing the exposure and training order failed to produce transfer. Initial lower SF training led to broad improvement of contrast sensitivity, and later higher SF training led to more specific improvement at high SFs. Training improved visual acuity by 1.5 to 1.6 lines (P orientations to enable learning transfer. Therefore, perceptual learning may improve amblyopic vision mainly through rule-based cognitive compensation.
Williams, Virginia P; Bishop-Fitzpatrick, Lauren; Lane, James D; Gwyther, Lisa P; Ballard, Edna L; Vendittelli, Analise P; Hutchins, Tiffany C; Williams, Redford B
To determine whether video-based coping skills (VCS) training with telephone coaching reduces psychosocial and biological markers of distress in primary caregivers of a relative with Alzheimer's disease or related dementia (ADRD). A controlled clinical trial was conducted with 116 ADRD caregivers who were assigned, alternately as they qualified for the study, to a Wait List control condition or the VCS training arm in which they viewed two modules/week of a version of the Williams LifeSkills Video adapted for ADRD family care contexts, did the exercises and homework for each module presented in an accompanying Workbook, and received one telephone coaching call per week for 5 weeks on each week's two modules. Questionnaire-assessed depressive symptoms, state and trait anger and anxiety, perceived stress, hostility, caregiver self-efficacy, salivary cortisol across the day and before and after a stress protocol, and blood pressure and heart rate during a stress protocol were assessed before VCS training, 7 weeks after training was completed, and at 3 months' and 6 months' follow-up. Compared with controls, participants who received VCS training plus telephone coaching showed significantly greater improvements in depressive symptoms, trait anxiety, perceived stress, and average systolic and diastolic blood pressures that were maintained over the 6-month follow-up period. VCS training augmented by telephone coaching reduced psychosocial and biological indicators of distress in ADRD caregivers. Future studies should determine the long-term benefits to mental and physical health from this intervention. http://www.clinicaltrials.gov; #NCT00396285.
Seitz, Aaron R; Yamagishi, Noriko; Werner, Birgit; Goda, Naokazu; Kawato, Mitsuo; Watanabe, Takeo
For more than a century, the process of stabilization has been a central issue in the research of learning and memory. Namely, after a skill or memory is acquired, it must be consolidated before it becomes resistant to disruption by subsequent learning. Although it is clear that there are many cases in which learning can be disrupted, it is unclear when learning something new disrupts what has already been learned. Herein, we provide two answers to this question with the demonstration that perceptual learning of a visual stimulus disrupts or interferes with the consolidation of a previously learned visual stimulus. In this study, we trained subjects on two different hyperacuity tasks and determined whether learning of the second task disrupted that of the first. We first show that disruption of learning occurs between visual stimuli presented at the same orientation in the same retinotopic location but not for the same stimuli presented at retinotopically disparate locations or different orientations at the same location. Second, we show that disruption from stimuli in the same retinotopic location is ameliorated if the subjects wait for 1 h before training on the second task. These results indicate that disruption, at least in visual learning, is specific to features of the tasks and that a temporal delay of 1 h can stabilize visual learning. This research shows that visual learning is susceptible to disruption and elucidates the processes by which the brain can consolidate learning and thus protect what is learned from being overwritten.
Sarani, Abdullah; Behtash, Esmail Zare; Nezhad Arani, Saieed Moslemi
This study aims at finding the effect of video-based tasks in improving the listening comprehension ability of Iranian pre-intermediate EFL (English Foreign Language) learners. After determining the level of learners, an experimental and control group, each of 20 participants, were nominated to contribute to the study. From the time the pre-test…
Zydney, Janet Mannheimer; Hooper, Simon
Educators can use video to gain invaluable information about their students. A concern is that collecting videos online can create an increased security risk for children. The purpose of this article is to provide ethical and legal guidelines for designing video-based apps for mobile devices and the web. By reviewing the literature, law, and code…
Vogler, Anna-Marietha; Prediger, Susanne
Video is often used in professional development courses to sensitize mathematics teachers to students' thinking and issues of classroom interaction. This article presents an approach that incorporates students' perspectives on mathematics classroom interactions into video-based professional development in order to enhance teachers' reflection on…
Pappas, Ilias O.; Giannakos, Michail N.; Mikalef, Patrick
The use of video-based open educational resources is widespread, and includes multiple approaches to implementation. In this paper, the term "with-video assignments" is introduced to portray video learning resources enhanced with assignments. The goal of this study is to examine the factors that influence students' intention to adopt…
Musdal, Hande; Shiner, Brian; Chen, Techieh; Ceyhan, Mehmet E; Watts, Bradley V; Benneyan, James
Post-traumatic stress disorder (PTSD) is associated with poor health but there is a gap between need and receipt of care. It is useful to understand where to optimally locate in-person care and where video-based PTSD care would be most useful to minimize access to care barriers, care outside the Veterans Affairs system, and total costs. We developed a service location systems engineering model based on 2010 to 2020 projected care needs for veterans across New England to help determine where to best locate and use in-person and video-based care. This analysis determined specific locations and capacities of each type of PTSD care relative to patient home locations to help inform allocation of mental health resources. Not surprisingly Massachusetts, Connecticut, and Rhode Island are well suited for in-person care, whereas some rural areas of Maine, Vermont, and New Hampshire where in-patient services are infeasible could be better served by video-based care than external care, if the latter is even available. Results in New England alone suggest a potential $3,655,387 reduction in average annual total costs by shifting 9.73% of care to video-based treatment, with an average 12.6 miles travel distance for the remaining in-person care. Reprint & Copyright © 2014 Association of Military Surgeons of the U.S.
Full Text Available Long-term music training can positively impact speech processing. A recent framework developed to explain such cross-domain plasticity posits that music training-related advantages in speech processing are due to shared cognitive and perceptual processes between music and speech. Although perceptual and cognitive processing advantages due to music training have been independently demonstrated, to date no study has examined perceptual and cognitive processing within the context of a single task. The present study examines the impact of long-term music training on speech learning from a rigorous, computational perspective derived from signal detection theory. Our computational models provide independent estimates of cognitive and perceptual processing in native English-speaking musicians (n=15, mean age= 25 years and non-musicians (n=15, mean age= 23 years learning to categorize non-native lexical pitch patterns (Mandarin tones. Musicians outperformed non-musicians in this task. Model-based analyses suggested that musicians shifted from simple unidimensional decision strategies to more optimal multidimensional decision strategies sooner than non-musicians. In addition, musicians used optimal decisional strategies more often than non-musicians. However, musicians and non-musicians who used multidimensional strategies showed no difference in performance. We estimated parameters that quantify the magnitude of perceptual variability along two dimensions that are critical for tone categorization: pitch height and pitch direction. Both musicians and non-musicians showed a decrease in perceptual variability along the pitch height dimension, but only musicians showed a significant reduction in perceptual variability along the pitch direction dimension. Notably, these advantages persisted during a generalization phase, when no feedback was provided. These results provide an insight into the mechanisms underlying the musician advantage observed in non
Smayda, Kirsten E; Chandrasekaran, Bharath; Maddox, W Todd
Long-term music training can positively impact speech processing. A recent framework developed to explain such cross-domain plasticity posits that music training-related advantages in speech processing are due to shared cognitive and perceptual processes between music and speech. Although perceptual and cognitive processing advantages due to music training have been independently demonstrated, to date no study has examined perceptual and cognitive processing within the context of a single task. The present study examines the impact of long-term music training on speech learning from a rigorous, computational perspective derived from signal detection theory. Our computational models provide independent estimates of cognitive and perceptual processing in native English-speaking musicians (n = 15, mean age = 25 years) and non-musicians (n = 15, mean age = 23 years) learning to categorize non-native lexical pitch patterns (Mandarin tones). Musicians outperformed non-musicians in this task. Model-based analyses suggested that musicians shifted from simple unidimensional decision strategies to more optimal multidimensional (MD) decision strategies sooner than non-musicians. In addition, musicians used optimal decisional strategies more often than non-musicians. However, musicians and non-musicians who used MD strategies showed no difference in performance. We estimated parameters that quantify the magnitude of perceptual variability along two dimensions that are critical for tone categorization: pitch height and pitch direction. Both musicians and non-musicians showed a decrease in perceptual variability along the pitch height dimension, but only musicians showed a significant reduction in perceptual variability along the pitch direction dimension. Notably, these advantages persisted during a generalization phase, when no feedback was provided. These results provide an insight into the mechanisms underlying the musician advantage observed in non-native speech learning.
Perceptual features are qualitative features used to describe music properties in relation to human perception instead of typical musical theory concepts such as pitches and chords. This report describes a music discovery platform which uses three different methods of music playlist generation to investigate if and how perceptual features work when used for music discovery. One method abstracts away the complexity of perceptual features and the other two lets users use them directly. Two user...
Scalability features embedded within the video sequences allows for streaming over heterogeneous networks to a variety of end devices. Compressive sensing techniques that will allow for lowering the complexity increase the robustness of the video scalability are reviewed. Human visual system models are often used in establishing perceptual metrics that would evaluate quality of video. Combining of perceptual and compressive sensing approach outlined from recent investigations. The performance and the complexity of different scalability techniques are evaluated. Application of perceptual models to evaluation of the quality of compressive sensing scalability is considered in the near perceptually lossless case and to the appropriate coding schemes is reviewed.
Bejjanki, Vikranth R; Zhang, Ruyuan; Li, Renjie; Pouget, Alexandre; Green, C Shawn; Lu, Zhong-Lin; Bavelier, Daphne
The field of perceptual learning has identified changes in perceptual templates as a powerful mechanism mediating the learning of statistical regularities in our environment. By measuring threshold-vs.-contrast curves using an orientation identification task under varying levels of external noise, the perceptual template model (PTM) allows one to disentangle various sources of signal-to-noise changes that can alter performance. We use the PTM approach to elucidate the mechanism that underlies the wide range of improvements noted after action video game play. We show that action video game players make use of improved perceptual templates compared with nonvideo game players, and we confirm a causal role for action video game play in inducing such improvements through a 50-h training study. Then, by adapting a recent neural model to this task, we demonstrate how such improved perceptual templates can arise from reweighting the connectivity between visual areas. Finally, we establish that action gamers do not enter the perceptual task with improved perceptual templates. Instead, although performance in action gamers is initially indistinguishable from that of nongamers, action gamers more rapidly learn the proper template as they experience the task. Taken together, our results establish for the first time to our knowledge the development of enhanced perceptual templates following action game play. Because such an improvement can facilitate the inference of the proper generative model for the task at hand, unlike perceptual learning that is quite specific, it thus elucidates a general learning mechanism that can account for the various behavioral benefits noted after action game play.
Gothberg, June E.
The purpose of this study was to examine the equivalence or non-inferiority for comparisons of telephone focus group venue to face-to-face focus group venue, Internet video-based focus group venue to face-to-face focus group venue, and Internet video-based focus group venue to telephone focus group venue. Research questions examined the…
Camilleri, Rebecca; Pavan, Andrea; Campana, Gianluca
It has recently been demonstrated how perceptual learning, that is an improvement in a sensory/perceptual task upon practice, can be boosted by concurrent high-frequency transcranial random noise stimulation (tRNS). It has also been shown that perceptual learning can generalize and produce an improvement of visual functions in participants with mild refractive defects. By using three different groups of participants (single-blind study), we tested the efficacy of a short training (8 sessions) using a single Gabor contrast-detection task with concurrent hf-tRNS in comparison with the same training with sham stimulation or hf-tRNS with no concurrent training, in improving visual acuity (VA) and contrast sensitivity (CS) of individuals with uncorrected mild myopia. A short training with a contrast detection task is able to improve VA and CS only if coupled with hf-tRNS, whereas no effect on VA and marginal effects on CS are seen with the sole administration of hf-tRNS. Our results support the idea that, by boosting the rate of perceptual learning via the modulation of neuronal plasticity, hf-tRNS can be successfully used to reduce the duration of the perceptual training and/or to increase its efficacy in producing perceptual learning and generalization to improved VA and CS in individuals with uncorrected mild myopia. Copyright © 2016 Elsevier Ltd. All rights reserved.
Lau, K H Vincent; Farooque, Pue; Leydon, Gary; Schwartz, Michael L; Sadler, R Mark; Moeller, Jeremy J
The video-based lecture (VBL), an important component of the flipped classroom (FC) and massive open online course (MOOC) approaches to medical education, has primarily been evaluated through direct learner feedback. Evaluation may be enhanced through learner analytics (LA) - analysis of quantitative audience usage data generated by video-sharing platforms. We applied LA to an experimental series of ten VBLs on electroencephalography (EEG) interpretation, uploaded to YouTube in the model of a publicly accessible MOOC. Trends in view count; total percentage of video viewed and audience retention (AR) (percentage of viewers watching at a time point compared to the initial total) were examined. The pattern of average AR decline was characterized using regression analysis, revealing a uniform linear decline in viewership for each video, with no evidence of an optimal VBL length. Segments with transient increases in AR corresponded to those focused on core concepts, indicative of content requiring more detailed evaluation. We propose a model for applying LA at four levels: global, series, video, and feedback. LA may be a useful tool in evaluating a VBL series. Our proposed model combines analytics data and learner self-report for comprehensive evaluation.
Horswill, Mark S; Hill, Andrew; Wetton, Mark
In 2008, the state of Queensland in Australia introduced a video-based hazard perception test as part of the licensing process for new drivers. A key validity check for such a test is whether scores are associated with crash involvement. We present data demonstrating that drivers who failed the hazard perception test (based on a ROC curve-derived pass mark) were 25% [95% confidence interval (CI) 6%, 48%] more likely to be involved in an active crash (defined as a crash occurring while the driver's vehicle was moving but they were not engaged in parking or reversing) during a one year period following the test (controlling for driving exposure, age, and sex). Failing drivers were also 17% (95% CI 6%, 29%) more likely to have been involved in active crashes prior to the test, in the period since obtaining their provisional license. These data support the proposal that the hazard perception test is a valid measure of crash-related driving performance. Copyright © 2015 Elsevier Ltd. All rights reserved.
Amosa Isiaka Gambari, PhD
Full Text Available The study examined the effects of video-based multimedia instruction on secondary school students' achievement and retention in biology. In Nigeria, 120 students (60 boys and 60 girls were randomly selected from four secondary schools assigned either into one of three experimental groups: Animation + Narration; Animation + On-screen Text; Animation + Narration + On-screen Text or a control group. The pretest, posttest experimental, and control group design was adopted. A 50-item multiple-choice objective test termed Biology Achievement Test (BAT was used for collecting data. The validated BAT was tested for reliability using Kuder Richardson (KR20, which yielded 0.89. T-test, analysis of covariance (ANCOVA, and Scheffe’s post-hoc analysis were used in determining the significant differences among the four groups. The results showed that there was no statistically significant difference among the experimental groups. Generally, students under multimedia instruction performed better than their colleagues in the conventional teaching method. However, students in conventional teaching method had better retention than other groups.
Wenzlaff, Frederike; Briken, Peer; Dekker, Arne
Although eye tracking has been used for decades, it has gained popularity in the area of sex research only recently. The aim of this article is to examine the potential merits of eye tracking for this field. We present a systematic review of the current use of video-based eye-tracking technology in this area, evaluate the findings, and identify future research opportunities. A total of 34 relevant studies published between 2006 and 2014 were identified for inclusion by means of online databases and other methods. We grouped them into three main areas of research: body perception and attractiveness, forensic research, and sexual orientation. Despite the methodological and theoretical differences across the studies, eye tracking has been shown to be a promising tool for sex research. The article suggests there is much potential for further studies to employ this technique because it is noninvasive and yet still allows for the assessment of both conscious and unconscious perceptional processes. Furthermore, eye tracking can be implemented in investigations of various theoretical backgrounds, ranging from biology to the social sciences.
Anishchenko, S.; Beylin, D.; Stepanov, P.; Stepanov, A.; Weinberg, I. N.; Schaeffer, S.; Zavarzin, V.; Shaposhnikov, D.; Smith, M. F.
Unintentional head motion during Positron Emission Tomography (PET) data acquisition can degrade PET image quality and lead to artifacts. Poor patient compliance, head tremor, and coughing are examples of movement sources. Head motion due to patient non-compliance can be an issue with the rise of amyloid brain PET in dementia patients. To preserve PET image resolution and quantitative accuracy, head motion can be tracked and corrected in the image reconstruction algorithm. While fiducial markers can be used, a contactless approach is preferable. A video-based head motion tracking system for a dedicated portable brain PET scanner was developed. Four wide-angle cameras organized in two stereo pairs are used for capturing video of the patient's head during the PET data acquisition. Facial points are automatically tracked and used to determine the six degree of freedom head pose as a function of time. The presented work evaluated the newly designed tracking system using a head phantom and a moving American College of Radiology (ACR) phantom. The mean video-tracking error was 0.99±0.90 mm relative to the magnetic tracking device used as ground truth. Qualitative evaluation with the ACR phantom shows the advantage of the motion tracking application. The developed system is able to perform tracking with accuracy close to millimeter and can help to preserve resolution of brain PET images in presence of movements.
Love, Elyse M; Manalo, Iviensan F; Chen, Suephy C; Chen, Kuang-Ho; Stoff, Benjamin K
Several treatment options exist for uncomplicated basal cell carcinoma. Standardized and effective informed consent is difficult in busy dermatology clinics. We investigated whether an educational video depicting 3 treatment options for uncomplicated basal cell carcinoma-excision, electrodessication and curettage, and topical therapy-before standard in-office informed consent affected patient knowledge and consent time compared with standard in-office consent alone. Patients were randomized to receive video education plus verbal discussion (video) or standard verbal discussion alone (control). Both groups completed baseline and final knowledge assessments. The primary outcome measure was change in knowledge scores between groups. Secondary outcomes were patient satisfaction, physician satisfaction, and informed consent time. In all, 32 eligible patients (16 control, 16 video) from an academic institution and affiliate Department of Veterans Affairs Medical Center dermatology clinics participated. The video group had significantly greater gains in knowledge compared with the control group (mean ± SD: 9 ± 3.6 vs 2.9 ± 2.2) (P = .0048). There was no significant difference in total consent time between groups. Patients and physicians were highly satisfied with the video. Small sample size and slight methodological difference between recruitment sites are limitations. Video-based education for basal cell carcinoma improved patient knowledge with no additional physician time when compared with standard communication. Published by Elsevier Inc.
Hua, Hong; Krishnaswamy, Prasanna; Rolland, Jannick P.
Head pose is utilized to approximate a user’s line-of-sight for real-time image rendering and interaction in most of the 3D visualization applications using head-mounted displays (HMD). The eye often reaches an object of interest before the completion of most head movements. It is highly desirable to integrate eye-tracking capability into HMDs in various applications. While the added complexity of an eyetracked-HMD (ET-HMD) imposes challenges on designing a compact, portable, and robust system, the integration offers opportunities to improve eye tracking accuracy and robustness. In this paper, based on the modeling of an eye imaging and tracking system, we examine the challenges and identify parametric requirements for video-based pupil-glint tracking methods in an ET-HMD design, and predict how these parameters may affect the tracking accuracy, resolution, and robustness. We further present novel methods and associated algorithms that effectively improve eye-tracking accuracy and extend the tracking range.
Patki, Aniruddha; Puscas, Liana
To determine whether instructional videos modeling examples of "good" and "bad" patient communication skills are useful as an educational tool for improving resident-patient communication. Retrospective study in which resident participants in the module gave survey responses indicating perceived utility of the exercise. Tertiary academic medical center. A total of 11 otolaryngology trainees from postgraduate year 1-5 who attended the course over 2 separate sessions and provided feedback on the benefits of the module. All 11 residents attended both sessions. Of 22 total survey responses, 21 found that the videos were "realistic and engaging" and were a true representation of commonly encountered clinical scenarios. Residents identified multiple themes and behaviors distinguishing "good" vs "bad" communication with patients and felt they could incorporate these into daily practice. A perceived weakness was the lack of opportunity for "role playing" with a video-based module as opposed to standardized patients. Instructional videos, when realistic, are useful for modeling effective patient communication skills for residents. By watching the videos, residents are able to identify specific techniques they can incorporate into their daily practice. Copyright © 2015 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.
Arnason, Arni; Tenga, Albin; Engebretsen, Lars; Bahr, Roald
The mechanisms for football injuries are largely unknown. To describe the characteristics of injury situations in elite male football using a video-based method called football incident analysis. Prospective cohort study. During the 1999 season, videotapes from 52 matches in the Icelandic elite football league were reviewed. Incidents (N = 95) were recorded when the match was interrupted by the referee because of a suspected injury. Team physical therapists recorded injuries prospectively (N = 28 time-loss injuries). Duels caused 84 of the incidents, mostly tackling duels (n = 54). The exposed player's attention appeared to be focused away from the opponent in 93% of the cases. The 3 main mechanisms observed were (1) breakdown attacks, tackling from the side or the front, attention focused on the ball (24%); (2) defensive tackling duels, attention focused on the ball or low ball control (20%); and (3) heading duels, attention focused on the ball in the air (13%). Most incidents and injuries occurred during breakdown attacks and when a player was involved in tackling duels. Player attention appeared to be focused mainly on the ball, not on the opponent challenging him to gain ball possession.
touch accuracy. (a) (b) (c) Figure 1: Computerized perceptual motor training (a) The training station includes a padded antimicrobial ...photographs of walking or road scenes, or videos taken from the point of view of a car driver (extracted from driver training videos from the UK Hazard...visual open loop aftereffects were larger and more resistant to decay than closed loop,29 presumably as a consequence of the lack of visual feedback
Zhang, Yu-Xuan; Tang, Ding-Lan; Moore, David R.; Amitay, Sygal
Medical rehabilitation involving behavioral training can produce highly successful outcomes, but those successes are obtained at the cost of long periods of often tedious training, reducing compliance. By contrast, arcade-style video games can be entertaining and highly motivating. We examine here the impact of video game play on contiguous perceptual training. We alternated several periods of auditory pure-tone frequency discrimination (FD) with the popular spatial visual-motor game Tetris p...
Banai, Karen; Lavner, Yizhar
Time-compressed speech, a form of rapidly presented speech, is harder to comprehend than natural speech, especially for non-native speakers. Although it is possible to adapt to time-compressed speech after a brief exposure, it is not known whether additional perceptual learning occurs with further practice. Here, we ask whether multiday training on time-compressed speech yields more learning than that observed during the initial adaptation phase and whether the pattern of generalization following successful learning is different than that observed with initial adaptation only. Two groups of non-native Hebrew speakers were tested on five different conditions of time-compressed speech identification in two assessments conducted 10-14 days apart. Between those assessments, one group of listeners received five practice sessions on one of the time-compressed conditions. Between the two assessments, trained listeners improved significantly more than untrained listeners on the trained condition. Furthermore, the trained group generalized its learning to two untrained conditions in which different talkers presented the trained speech materials. In addition, when the performance of the non-native speakers was compared to that of a group of naïve native Hebrew speakers, performance of the trained group was equivalent to that of the native speakers on all conditions on which learning occurred, whereas performance of the untrained non-native listeners was substantially poorer. Multiday training on time-compressed speech results in significantly more perceptual learning than brief adaptation. Compared to previous studies of adaptation, the training induced learning is more stimulus specific. Taken together, the perceptual learning of time-compressed speech appears to progress from an initial, rapid adaptation phase to a subsequent prolonged and more stimulus specific phase. These findings are consistent with the predictions of the Reverse Hierarchy Theory of perceptual
Full Text Available Perceptual adaptation allows humans to understand a variety of accented speech. We investigated whether perceptual adaptation to accented speech is facilitated if listeners can see a speaker’s facial and mouth movements. In Study 1, participants listened to sentences in a novel accent and underwent a period of training with audiovisual or audio-only speech cues, presented in quiet or in background noise. A control group also underwent training with visual-only (speech-reading cues. We observed no significant difference in perceptual adaptation between any of the groups. To address a number of remaining questions, we carried out a second study using a different accent, speaker and experimental design, in which participants listened to sentences in a non-native (Japanese accent with audiovisual or audio-only cues, without separate training. Participants’ eye gaze was recorded to verify that they looked at the speaker’s face during audiovisual trials. Recognition accuracy was significantly better for audiovisual than audio-only stimuli; however, no statistical difference in perceptual adaptation was observed between the two modalities. Furthermore, Bayesian analysis suggested that the data supported the null hypothesis. Our results suggest that although the availability of visual speech cues may be immediately beneficial for recognition of unfamiliar accented speech in noise, they do not improve perceptual adaptation.
Carlo Ghirardi, Gian; Romano, Raffaele
Theories including a collapse mechanism have been presented various years ago. They are based on a modification of standard quantum mechanics in which nonlinear and stochastic terms are added to the evolution equation. Their principal merits derive from the fact that they are mathematically precise schemes accounting, on the basis of a unique universal dynamical principle, both for the quantum behavior of microscopic systems as well as for the reduction associated to measurement processes and for the classical behavior of macroscopic objects. Since such theories qualify themselves not as new interpretations but as modifications of the standard theory they can be, in principle, tested against quantum mechanics. Recently, various investigations identifying possible crucial test have been discussed. In spite of the extreme difficulty to perform such tests it seems that recent technological developments allow at least to put precise limits on the parameters characterizing the modifications of the evolution equation. Here we will simply mention some of the recent investigations in this direction, while we will mainly concentrate our attention to the way in which collapse theories account for definite perceptual process. The differences between the case of reductions induced by perceptions and those related to measurement procedures by means of standard macroscopic devices will be discussed. On this basis, we suggest a precise experimental test of collapse theories involving conscious observers. We make plausible, by discussing in detail a toy model, that the modified dynamics can give rise to quite small but systematic errors in the visual perceptual process.
Chiang, I-Ping; Lin, Chih-Ying; Wang, Kaisheng M
Many companies have launched their products or services online as a new business focus, but only a few of them have survived the competition and made profits. The most important key to an online business's success is to create "brand value" for the customers. Although the concept of online brand has been discussed in previous studies, there is no empirical study on the measurement of online branding. As Web 2.0 emerges to be critical to online branding, the purpose of this study was to measure Taiwan's major Web sites with a number of personality traits to build a perceptual map for online brands. A pretest identified 10 most representative online brand perceptions. The results of the correspondence analysis showed five groups in the perceptual map. This study provided a practical view of the associations and similarities among online brands for potential alliance or branding strategies. The findings also suggested that brand perceptions can be used with identified consumer needs and behaviors to better position online services. The brand perception map in the study also contributed to a better understanding of the online brands in Taiwan.
Holcomb, Lynn; Berger, Leonard
A study was conducted to determine any perceptual differences toward quality circles in a chemical plant. It also tried to determine if any perceptual differences that might be found could be related to attitudes toward the circles themselves or the attitudes toward circle members. Length of service was also a factor. (CT)
Cratty, Bryant J.
Addressed to elementary school and special class teachers, the text presents research-based information on perceptual-motor behavior and education, including movement and the human personality, research guidelines, and movement activities in general education. Special education is considered and perceptual motor abilities are discussed with…
Vonk, Matthew; Bohacek, Peter; Militello, Cheryl; Iverson, Ellen
This study focuses on student development of two important laboratory skills in the context of introductory college-level physics. The first skill, which we call model making, is the ability to analyze a phenomenon in a way that produces a quantitative multimodal model. The second skill, which we call model breaking, is the ability to critically evaluate if the behavior of a system is consistent with a given model. This study involved 116 introductory physics students in four different sections, each taught by a different instructor. All of the students within a given class section participated in the same instruction (including labs) with the exception of five activities performed throughout the semester. For those five activities, each class section was split into two groups; one group was scaffolded to focus on model-making skills and the other was scaffolded to focus on model-breaking skills. Both conditions involved direct measurement videos. In some cases, students could vary important experimental parameters within the video like mass, frequency, and tension. Data collected at the end of the semester indicate that students in the model-making treatment group significantly outperformed the other group on the model-making skill despite the fact that both groups shared a common physical lab experience. Likewise, the model-breaking treatment group significantly outperformed the other group on the model-breaking skill. This is important because it shows that direct measurement video-based instruction can help students acquire science-process skills, which are critical for scientists, and which are a key part of current science education approaches such as the Next Generation Science Standards and the Advanced Placement Physics 1 course.
Wang, Fang; Huang, Jing; Lv, Yaping; Ma, Xiaoli; Yang, Bin; Wang, Encong; Du, Boqi; Li, Wu; Song, Yan
Visual perceptual learning has been shown to be highly specific to the retinotopic location and attributes of the trained stimulus. Recent psychophysical studies suggest that these specificities, which have been associated with early retinotopic visual cortex, may in fact not be inherent in perceptual learning and could be related to higher-order brain functions. Here we provide direct electrophysiological evidence in support of this proposition. In a series of event-related potential (ERP) experiments, we recorded high-density electroencephalography (EEG) from human adults over the course of learning in a texture discrimination task (TDT). The results consistently showed that the earliest C1 component (68-84ms), known to reflect V1 activity driven by feedforward inputs, was not modulated by learning regardless of whether the behavioral improvement is location specific or not. In contrast, two later posterior ERP components (posterior P1 and P160-350) over the occipital cortex and one anterior ERP component (anterior P160-350) over the prefrontal cortex were progressively modified day by day. Moreover, the change of the anterior component was closely correlated with improved behavioral performance on a daily basis. Consistent with recent psychophysical and imaging observations, our results indicate that perceptual learning can mainly involve changes in higher-level visual cortex as well as in the neural networks responsible for cognitive functions such as attention and decision making. Copyright © 2015 Elsevier Inc. All rights reserved.
Full Text Available This exploratory study intends to model kinematics learning of a pair of student teachers when exposed to prescribed teaching strategies in a video-based laboratory. Two student teachers were chosen from the Francophone B.Ed. program of the Faculty of Education of a Canadian university. The study method consisted of having the participants interact with a video-based laboratory to complete two activities for learning properties of acceleration in rectilinear motion. Time limits were placed on the learning activities during which the researcher collected detailed multimodal information from the student teachers' answers to questions, the graphs they produced from experimental data, and the videos taken during the learning sessions. As a result, we describe the learning approach each one followed, the evidence of conceptual change and the difficulties they face in tackling various aspects of the accelerated motion. We then specify advantages and limits of our research and propose recommendations for further study.
Currently, many placement-based health programme students within the UK are supported through face-to-face visits from university staff. Whilst cited in literature as being of value, the face-to-face nature of this contact is not supported. Alternatives including video-based communications methods offer the potential for cost effective, environmentally responsible support. However, in order to establish the fitness for purpose of alternative approaches, the content and purpose of current supp...
Sofia Backåberg; Mikael Rask; Christina Gummesson; David Brunt
The aim of this study is to describe an interactive model developed for movement awareness in a practical learning situation and to explore the use of video-based digital feedback and reflective enquiry in this model among nursing students. Sixteen students participated in individual interactive video sessions with a facilitator, who encouraged the students to reflect upon their own movements. Qualitative analysis showed that movement patterns were visualized, and that movement awareness and ...
Thomas W Weickert
Full Text Available Previous studies of perceptual category learning in patients with schizophrenia generally demonstrate impaired perceptual category learning; however, traditional cognitive studies have often failed to address the relationship of different cortical regions to perceptually based category learning and judgments in healthy participants and patients with schizophrenia. In the present study, perceptual category learning was examined in 26 patients with schizophrenia and 25 healthy participants using a dot-pattern category learning task. In the training phase, distortions of a prototypical dot-pattern were presented. In the test phase, participants were shown the prototype, low and high distortions of the prototype, and random dot-patterns. Participants were required to indicate whether the presented dot pattern was a member of the category of dot patterns previously presented during the study phase. Patients with schizophrenia displayed an impaired ability to make judgments regarding marginal members of novel, perceptually-based categories relative to healthy participants. Category judgment also showed opposite patterns of strong, significant correlations with behavioral measures of prefrontal cortex function in patients relative to healthy participants. These results suggest that impaired judgments regarding novel, perceptually based category membership may be due to abnormal prefrontal cortex function in patients with schizophrenia.
Hordacre, Brenton; Immink, Maarten A; Ridding, Michael C; Hillier, Susan
The purpose of this study was to manipulate psychological stress and anxiety to investigate effects on ensuing perceptual-motor learning. Thirty-six participants attended two experimental sessions separated by 24h. In the first session, participants were randomized to either a mental arithmetic task known to increase stress and anxiety levels or a control condition and subsequently completed training on a speeded precision pinch task. Learning of the pinch task was assessed at the second session. Those exposed to the high stress-anxiety mental arithmetic task prior to training reported elevated levels of both stress and anxiety and demonstrated shorter movement times and improved retention of movement accuracy and movement variability. Response execution processes appear to benefit from elevated states of stress and anxiety immediately prior to training even when elicited by an unrelated task. Copyright © 2016 Elsevier B.V. All rights reserved.
Full Text Available As video-based instructional materials become available to distance learners to learn practical skills at a distance, it is important to assess the instructional effectiveness of these materials and to understand how students respond to them. This paper is the second part of a larger exploratory study that assessed the instructional effectiveness of video-based instructional materials for teaching distance learners practical skills in block-laying and concreting and how learners respond to these instructional materials. Specifically, this paper aims to assess learners’ acceptance and satisfaction with the materials. It also aims to determine whether levels of learner satisfaction and acceptance differ according to study centres. Data were collected from 71 respondents at three study centres using a self-completion questionnaire comprising 17 Likert-type items. The data were analyzed using descriptive statistics, ANOVA, and Scheffe’s post hoc test at a 0.05 level of significance. Learners appeared positive about their learning experiences with the use of video-based instructional materials to learn practical skills at a distance as they rated highly all the items assessing their acceptance and satisfaction. Results of item-by-item ANOVA regarding learner acceptance indicated that the respondents, categorized according to study centres, exhibited similar levels of acceptance for nine of the ten items. For learner satisfaction, there were no statistically significant differences for six of the seven items. Thus, learners of different study centres exhibited about the same level of acceptance and satisfaction.
Decreasing sprint duration from 20 to 10 s during reduced-exertion high-intensity interval training (REHIT) attenuates the increase in maximal aerobic capacity but has no effect on affective and perceptual responses.
Nalcakan, Gulbin R; Songsorn, Preeyaphorn; Fitzpatrick, Ben L; Yuzbasioglu, Yasin; Brick, Noel E; Metcalfe, Richard S; Vollaard, Niels Bj
Recent studies have demonstrated that modifying the 'classic' 6x30-s 'all-out' sprint interval training (SIT) protocol by incorporating either shorter sprints (6x10-s or 15-s sprints) or fewer sprints (e.g. 2x20-s sprints; reduced-exertion high-intensity interval training (REHIT)) does not attenuate the training-induced improvements in maximal aerobic capacity (V̇O2max). The aim of the present study was to determine whether reducing the sprint duration in the REHIT protocol from 20 s to 10 s per sprint influences acute affective responses and the change in V̇O2max following training. Thirty-six sedentary or recreationally active participants (17 women; mean±SD age: 22±3 y, BMI: 24.5±4.6 kg·m-2, V̇O2max: 37±8 mL·kg-1·min-1) were randomised to a group performing a 'standard' REHIT protocol involving 2x20-s sprints or a group who performed 2x10-s sprints. V̇O2max was determined before and after 6 weeks of 3 weekly training sessions. Acute affective responses and perceived exertion were assessed during training. Greater increases in V̇O2max were observed for the group performing 20-s sprints (2.77±0.75 to 3.04±0.75 L·min-1; +10%) compared to the group performing 10-s sprints (2.58±0.57 vs. 2.67±3.04 L·min-1; +4%; group×time interaction effect: ps to 10 s attenuates improvements in V̇O2max, and does not result in more positive affective responses or lower perceived exertion.
Queen, Jennifer S.; Nygaard, Lynne C.
Previous research suggests that as listeners become familiar with a speaker's vocal style, they are better able to understand that speaker. This study investigated one possible mechanism by which this talker familiarity benefit arises. Listeners' vowel spaces were measured using a perceptual discrimination test both before and after they were trained to identify a group of speakers by name. Listeners identified either the same speakers whose vowels they discriminated or a different group of speakers. Differences in the learnability and the intelligibility of the two speaking groups were observed. The speaker group that was harder to identify also had vowels that were harder to discriminate. Changes in the listeners' vowel spaces were determined by examining multidimensional scaling solutions of their responses during the discrimination tests. All listeners became better at discriminating vowels. However, only listeners who heard different speakers during identification training and vowel discrimination exhibited a shift in their vowel spaces after training. This suggests that encountering new voices in an unrelated, nonlinguistic task acts to alter the perceptual context and may affect the structure of linguistic representation. Together, these results suggest a link between linguistic and nonlinguistic information in representations for spoken language.
Bocast, Christopher S.
A portfolio dissertation that began as acoustic ecology and matured into perceptual ecology, centered on ecomusicology, bioacoustics, and translational audio-based media works with environmental perspectives. The place of music in Western eco-cosmology through time provides a basis for structuring an environmental history of human sound perception. That history suggests that music may stabilize human mental activity, and that an increased musical practice may be essential for the human project. An overview of recent antecedents preceding the emergence of acoustic ecology reveals structural foundations from 20th century culture that underpin modern sound studies. The contextual role that Aldo Leopold, Jacob von Uexkull, John Cage, Marshall McLuhan, and others played in anticipating the development of acoustic ecology as an interdiscipline is detailed. This interdisciplinary aspect of acoustic ecology is defined and defended, while new developments like soundscape ecology are addressed, though ultimately sound studies will need to embrace a broader concept of full-spectrum "sensory" or "perceptual" ecology. The bioacoustic fieldwork done on spawning sturgeon emphasized this necessity. That study yielded scientific recordings and spectrographic analyses of spawning sounds produced by lake sturgeon, Acipenser fulvescens, during reproduction in natural habitats in the Lake Winnebago watershed in Wisconsin. Recordings were made on the Wolf and Embarrass River during the 2011-2013 spawning seasons. Several specimens were dissected to investigate possible sound production mechanisms; no sonic musculature was found. Drumming sounds, ranging from 5 to 7 Hz fundamental frequency, verified the infrasonic nature of previously undocumented "sturgeon thunder". Other characteristic noises of sturgeon spawning including low-frequency rumbles and hydrodynamic sounds were identified. Intriguingly, high-frequency signals resembling electric organ discharges were discovered. These
Butts, Sydney C; Truong, Alan; Forde, Christina; Stefanov, Dimitre G; Marrinan, Eileen
To assess the ability of otolaryngology residents to rate the hypernasal resonance of patients with velopharyngeal dysfunction. We hypothesize that experience (postgraduate year [PGY] level) and training will result in improved ratings of speech samples. Prospective cohort study. Otolaryngology training programs at 2 academic medical centers. Thirty otolaryngology residents (PGY 1-5) were enrolled in the study. All residents rated 30 speech samples at 2 separate times. Half the residents completed a training module between the rating exercises, with the other half serving as a control group. Percentage agreement with the expert rating of each speech sample and intrarater reliability were calculated for each resident. Analysis of covariance was used to model accuracy at session 2. The median percentage agreement at session 1 was 53.3% for all residents. At the second session, the median scores were 53.3% for the control group and 60% for the training group, but this difference was not statistically significant. Intrarater reliability was moderate for both groups. Residents were more accurate in their ratings of normal and severely hypernasal speech. There was no correlation between rating accuracy and PGY level. Score at session 1 positively correlated with score at session 2. Perceptual training of otolaryngology residents has the potential to improve their ratings of hypernasal speech. Length of time in residency may not be best predictor of perceptual skill. Training modalities incorporating practice with hypernasal speech samples could improve rater skills and should be studied more extensively. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.
needs within the education environment and that many schools are under-supplied in terms of resources and equipment. It is recommended that these teachers receive inservice training on learners’ perceptual motor development and that the Department of Education should provide schools with resources and equipment to prevent these deficiencies in the education system.
Fields, Lanny; Fitzer, Adrienne; Shamoun, Kimberly; Matneja, Priya; Watanabe, Mari; Tittelbach, Danielle
After training conditional discriminations among selected stimuli from two perceptual classes, the emergence of novel relations involving other members of both classes was assessed using cross-class probes. The cross-class probes were presented using one of four different testing schedules. In the 2/9 test, nine different probes were presented in…
Aziz Aadam, A; Wani, Sachin; Kahi, Charles; Kaltenbach, Tonya; Oh, Young; Edmundowicz, Steven; Peng, Jie; Rademaker, Alfred; Patel, Swati; Kushnir, Vladimir; Venu, Mukund; Soetikno, Roy; Keswani, Rajesh N
The management of complex colorectal polyps varies in practice. Accurate descriptions of the endoscopic appearance by using a standardized classification system (Paris classification) and size for complex colon polyps may guide subsequent providers regarding curative endoscopic resection vs. need for surgery. The accuracy of this assessment is not well defined. Furthermore, the factors associated with decisions for endoscopic vs. surgical management are unclear. To characterize the accuracy of physician assessment of polyp morphology, size, and suspicion for malignancy among physician subspecialists performing colonoscopy and colon surgery. In addition, we aimed to assess the influence of these polyp characteristics as well as physician type and patient demographics on recommendations for endoscopic vs. surgical resection of complex colorectal polyps. An online video-based survey was sent to gastroenterologists (GIs) and gastrointestinal surgeons affiliated with six tertiary academic centers. The survey consisted of high-definition video clips (30-60 s) of six complex colorectal polyps (one malignant) and clinical histories. Respondents were blinded to histology. Respondents were queried regarding polyp characteristics, suspicion for malignancy, and recommendations for resection. The survey response rate was 154/317 (49%). Seventy-eight percent of respondents were attending physicians (91 GIs and 29 surgeons) and 22% were GI trainees. Sixteen percent of respondents self-identified as specialists in complex polypectomy. Accurate estimation of polyp size was poor (28.4%) with moderate interobserver agreement (k=0.52). Accuracy for Paris classification was 47.5%, also with moderate interobserver agreement (k=0.48). Specialists in complex polypectomy were most accurate, whereas surgeons were the least accurate in assigning Paris classification (66.0 vs. 28.7%, Ppolyp morphology (polypoid vs. nonpolypoid), polyp location (right vs. left colon), or patient ASA class. In
Paro, John A M; Nazareli, Rahim; Gurjala, Anadev; Berger, Aaron; Lee, Gordon K
Professionals in a variety of specialties use video-based review as a method of constant self-evaluation. We believe critical self-reflection will allow a surgical trainee to identify methods for improvement throughout residency and beyond. We have used 2 new popular technologies to evaluate their role in accomplishing the previously mentioned objectives. Our group investigated Google Glass and GoPro cameras. Medical students, residents, and faculty were invited to wear each of the devices during a scheduled operation. After the case, each participant was asked to comment on a number of features of the device including comfort, level of distraction/interference with operating, ease of video acquisition, and battery life. Software and hardware specifications were compiled and compared by the authors. A "proof-of-concept" was also performed using the video-conferencing abilities of Google Glass to perform a simulated flap check. The technical specifications of the 2 cameras favor GoPro over Google Glass. Glass records in 720p with 5-MP still shots, and the GoPro records in 1080p with 12-MP still shots. Our tests of battery life showed more than 2 hours of continuous video with GoPro, and less than 1 hour for Glass. Favorable features of Google Glass included comfort and relative ease of use; they could not comfortably wear loupes while operating, and would have preferred longer hands-free video recording. The GoPro was slightly more cumbersome and required a nonsterile team member to activate all pictures or video; however, loupes could be worn. Google Glass was successfully used in the hospital for a simulated flap check, with overall audio and video being transmitted--fine detail was lost, however. There are benefits and limitations to each of the devices tested. Google Glass is in its infancy and may gain a larger intraoperative role in the future. We plan to use Glass as a way for trainees to easily acquire intraoperative footage as a means to "review tape" and
Full Text Available Increase in number of elderly people who are living independently needs especial care in the form of healthcare monitoring systems. Recent advancements in depth video technologies have made human activity recognition (HAR realizable for elderly healthcare applications. In this paper, a depth video-based novel method for HAR is presented using robust multi-features and embedded Hidden Markov Models (HMMs to recognize daily life activities of elderly people living alone in indoor environment such as smart homes. In the proposed HAR framework, initially, depth maps are analyzed by temporal motion identification method to segment human silhouettes from noisy background and compute depth silhouette area for each activity to track human movements in a scene. Several representative features, including invariant, multi-view differentiation and spatiotemporal body joints features were fused together to explore gradient orientation change, intensity differentiation, temporal variation and local motion of specific body parts. Then, these features are processed by the dynamics of their respective class and learned, modeled, trained and recognized with specific embedded HMM having active feature values. Furthermore, we construct a new online human activity dataset by a depth sensor to evaluate the proposed features. Our experiments on three depth datasets demonstrated that the proposed multi-features are efficient and robust over the state of the art features for human action and activity recognition.
Full Text Available Our ability to listen selectively to single sound sources in complex auditory environments is termed ‘auditory stream segregation.’ This ability is affected by peripheral disorders such as hearing loss, as well as plasticity in central processing such as occurs with musical training. Brain plasticity induced by musical training can enhance the ability to segregate sound, leading to improvements in a variety of auditory abilities. The melody segregation ability of 12 cochlear-implant recipients was tested using a new method to determine the perceptual distance needed to segregate a simple 4-note melody from a background of interleaved random-pitch distractor notes. In experiment 1, participants rated the difficulty of segregating the melody from distracter notes. Four physical properties of the distracter notes were changed. In experiment 2, listeners were asked to rate the dissimilarity between melody patterns whose notes differed on the four physical properties simultaneously. Multidimensional scaling analysis transformed the dissimilarity ratings into perceptual distances. Regression between physical and perceptual cues then derived the minimal perceptual distance needed to segregate the melody.The most efficient streaming cue for CI users was loudness. For the normal hearing listeners without musical backgrounds, a greater difference on the perceptual dimension correlated to the temporal envelope is needed for stream segregation in CI users. No differences in streaming efficiency were found between the perceptual dimensions linked to the F0 and the spectral envelope.Combined with our previous results in normally-hearing musicians and non-musicians, the results show that differences in training as well as differences in peripheral auditory processing (hearing impairment and the use of a hearing device influences the way that listeners use different acoustic cues for segregating interleaved musical streams.
Folker, Joanne; Murdoch, Bruce; Cahill, Louise; Delatycki, Martin; Corben, Louise; Vogel, Adam
The aims of this study were to: (1) evaluate the perceptual speech dimensions, speech intelligibility and dysarthria severity of a group of individuals diagnosed with Friedreich's ataxia (FRDA); (2...
Caras, Melissa L.; Sanes, Dan H.
Sensory pathways display heightened plasticity during development, yet the perceptual consequences of early experience are generally assessed in adulthood. This approach does not allow one to identify transient perceptual changes that may be linked to the central plasticity observed in juvenile animals. Here, we determined whether a brief period of bilateral auditory deprivation affects sound perception in developing and adult gerbils. Animals were reared with bilateral earplugs, either from ...
Esin, R G; Khairullin, I Kh; Mukhametova, E R; Esin, O R
To study persistent postural perceptual dizziness (PPPD) in outpatients with benign paroxysmal positional vertigo (BPPV) and patients with presbiataxia (PAt). Eighty-four patients with PPPD, including 14 with Meniere's disease (MD), 19 with BPPV, 17 with a history of ischemic stroke (IS) in the vertebrobasilar system and 34 with Pat, were examined. For the diagnosis of anxiety, the original 15-point questionnaire with the Likert Scale structure was used. Patients received anvifen (aminophenylbutyric acid hydrochloride) in dose of 250 mg 3 times a day for 6 weeks. Results and сonclusion. The most common trigger of PPPD was sleep deprivation. The highest level of anxiety was identified in the PAt group (19,5±2,89). There was a good effect of the drug: it reduced anxiety in all patients studied. The quality of sleep was improved as well. The authors recommend anvifen as the drug of choice in patients with PPPD during vestibular rehabilitation and cognitive-behavioral therapy.
Ludwig, Casimir J H; Evens, David R
We tested an information foraging framework to characterize the mechanisms that drive active (visual) sampling behavior in decision problems that involve multiple sources of information. Experiments 1 through 3 involved participants making an absolute judgment about the direction of motion of a single random dot motion pattern. In Experiment 4, participants made a relative comparison between 2 motion patterns that could only be sampled sequentially. Our results show that: (a) Information (about noisy motion information) grows to an asymptotic level that depends on the quality of the information source; (b) The limited growth is attributable to unequal weighting of the incoming sensory evidence, with early samples being weighted more heavily; (c) Little information is lost once a new source of information is being sampled; and (d) The point at which the observer switches from 1 source to another is governed by online monitoring of his or her degree of (un)certainty about the sampled source. These findings demonstrate that the sampling strategy in perceptual decision-making is under some direct control by ongoing cognitive processing. More specifically, participants are able to track a measure of (un)certainty and use this information to guide their sampling behavior. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Lu, Zhong-Lin; Chu, Wilson; Dosher, Barbara Anne; Lee, Sophia
Eye-transfer tests, external noise manipulations, and observer models were used to systematically characterize learning mechanisms in judging motion direction of moving objects in visual periphery (Experiment 1) and fovea (Experiment 2) and to investigate the degree of transfer of the learning mechanisms from trained to untrained eyes. Perceptual learning in one eye was measured over 10 practice sessions. Subsequent learning in the untrained eye was assessed in five transfer sessions. We characterized the magnitude of transfer of each learning mechanism to the untrained eye by separately analyzing the magnitude of subsequent learning in low and high external noise conditions. In both experiments, we found that learning in the trained eye reduced contrast thresholds uniformly across all of the external noise levels: 47 +/- 10% and 62 +/- 8% in experiments 1 and 2, respectively. Two mechanisms, stimulus enhancement and template retuning, accounted for the observed performance improvements. The degree of transfer to the untrained eye depended on the amount of external noise added to the signal stimuli: In high external noise conditions, learning transferred completely to the untrained eye in both experiments. In low external noise conditions, there was only partial transfer of learning: 63% in experiment 1 and 54% in experiment 2. The results suggest that template retuning, which is effective in high external noise conditions, is mostly binocular, whereas stimulus enhancement, which is effective in low external noise displays, is largely monocular. The two independent mechanisms underlie perceptual learning of motion direction identification in monocular and binocular motion systems.
Carter, Olivia L; Pettigrew, John D
Perceptual rivalry is an oscillation of conscious experience that takes place despite univarying. if ambiguous, sensory input. Much current interest is focused on the controversy over the neural site of binocular rivalry, a variety of perceptual rivalry for which a number of different cortical regions have been implicated. Debate continues over the relative role of higher levels of processing compared with primary visual cortex and the suggestion that different forms of rivalry involve different cortical areas. Here we show that the temporal pattern of disappearance and reappearance in motion-induced blindness (MIB) (Bonneh et al, 2001 Nature 411 798-801) is highly correlated with the pattern of oscillation reported during binocular rivalry in the same individual. This correlation holds over a wide range of inter-individual variation. Temporal similarity in the two phenomena was strikingly confirmed by the effects of the hallucinogen LSD, which produced the same, extraordinary, pattern of increased rhythmicity in both kinds of perceptual oscillation. Furthermore. MIB demonstrates the two properties previously considered characteristic of binocular rivalry. Namely the distribution of dominance periods can be approximated by a gamma distribution and, in line with Levelt's second proposition of binocular rivalry, predominance of one perceptual phase can be increased through a reduction in the predominance time of the opposing phase. We conclude that (i) MIB is a form of perceptual rivalry, and (ii) there may be a common oscillator responsible for timing aspects of all forms of perceptual rivalry.
Full Text Available Workplace interventions have shown beneficial results of resistance training for chronic pain in the neck, shoulder, and arm. However, studies have relied on experienced exercise instructors, which may not be an available resource at most workplaces. The objective of this study is to evaluate the technical performance level of upper limb rehabilitation exercises following video-based versus personalized exercise instruction. We recruited 38 laboratory technicians and office workers with neck/shoulder pain for a two-week exercise training period receiving either (1 personal and video or (2 video only instruction in four typical neck/shoulder/arm rehabilitation exercises using elastic tubing. At a 2-week follow-up, the participants’ technical execution was assessed by two blinded physical therapists using a reliable error assessment tool. The error assessment was based on ordinal deviation of joint position from the ideal position of the shoulder, elbow, and wrist in a single plane by visual observation. Of the four exercises only unilateral shoulder external rotation had a higher normalized error score in the V group of 22.19 (9.30 to 12.64 (6.94 in the P group (P=0.002. For the remaining three exercises the normalized error score did not differ. In conclusion, when instructing simple exercises to reduce musculoskeletal pain the use of video material is a cost-effective solution that can be implemented easily in corporations with challenging work schedules not allowing for a fixed time of day to go see a personal trainer.
Addison, Paul S; Jacquel, Dominique; Foo, David M H; Antunes, André; Borg, Ulf R
The physiologic information contained in the video photoplethysmogram is well documented. However, extracting this information during challenging conditions requires new analysis techniques to capture and process the video image streams to extract clinically useful physiologic parameters. We hypothesized that heart rate, respiratory rate, and oxygen saturation trending can be evaluated accurately from video information during acute hypoxia. Video footage was acquired from multiple desaturation episodes during a porcine model of acute hypoxia using a standard visible light camera. A novel in-house algorithm was used to extract photoplethysmographic cardiac pulse and respiratory information from the video image streams and process it to extract a continuously reported video-based heart rate (HRvid), respiratory rate (RRvid), and oxygen saturation (SvidO2). This information was then compared with HR and oxygen saturation references from commercial pulse oximetry and the known rate of respiration from the ventilator. Eighty-eight minutes of data were acquired during 16 hypoxic episodes in 8 animals. A linear mixed-effects regression showed excellent responses relative to a nonhypoxic reference signal with slopes of 0.976 (95% confidence interval [CI], 0.973-0.979) for HRvid; 1.135 (95% CI, 1.101-1.168) for RRvid, and 0.913 (95% CI, 0.905-0.920) for video-based oxygen saturation. These results were obtained while maintaining continuous uninterrupted vital sign monitoring for the entire study period. Video-based monitoring of HR, RR, and oxygen saturation may be performed with reasonable accuracy during acute hypoxic conditions in an anesthetized porcine hypoxia model using standard visible light camera equipment. However, the study was conducted during relatively low motion. A better understanding of the effect of motion and the effect of ambient light on the video photoplethysmogram may help refine this monitoring technology for use in the clinical environment.
Full Text Available Introduction: Various different learning methods are available for planning tuition regarding the introduction to surgical hand disinfection. These learning methods should help to organise and deal with this topic. The use of a video film is an alternative to conventional tuition due to the real presentation possibilities of practical demonstration. Objective: This study examines by way of comparison which form of communication is more effective for learning and applying surgical hand disinfection for medical students in their first year of studies: video-based instruction or conventional tuition. Methodology: A total of 50 first-year medical students were randomly allocated either to the “Conventional Instruction” (CI study group or to the “Video-based Instruction” (VI study group. The conventional instruction was carried out by an experienced nurse preceptor/nurse educator for the operating theatre who taught the preparatory measures and the actual procedure in a two-minute lesson. The second group watched a two-minute video sequence with identical content. Afterwards, both groups demonstrated practically the knowledge they had acquired at an individual practical test station. The quality (a of the preparation and (b of the procedure as well as (c the quality of the results was assessed by 6 blind experts using a check list. The acceptability of the respective teaching method was also asked about using a questionnaire.Results: The group performance did not differ either in the preparation (=-78, <0.44 or in the quality (=-99, <0.34. With respect to performance, it was possible to demonstrate a strong treatment effect. In the practical (=-3.33, <0.002, =0.943 and in the total score (=-2.65, <0.011, =0.751, the group with video-based instruction achieved a significantly better result. In response to the question as to which of the two learning methods they would prefer, the significant majority (60.4% of students stated video instruction
Haque, Mohammad Ahsanul; Irani, Ramin; Nasrollahi, Kamal
Physical fatigue reveals the health condition of a person at for example health checkup, fitness assessment or rehabilitation training. This paper presents an efficient noncontact system for detecting non-localized physi-cal fatigue from maximal muscle activity using facial videos acquired...
Mulligan, Neil W.; Dew, Ilana T. Z.
The generation manipulation has been critical in delineating differences between implicit and explicit memory. In contrast to past research, the present experiments indicate that generating from a rhyme cue produces as much perceptual priming as does reading. This is demonstrated for 3 visual priming tasks: perceptual identification, word-fragment…
Helle, Laura; Nivala, Markus; Kronqvist, Pauliina; Ericsson, K Anders; Lehtinen, Erno
OBJECTIVES There has been long-standing controversy regarding aptitude testing and selection for medical education. Visual perception is considered particularly important for detecting signs of disease as part of diagnostic procedures in, for example, microscopic pathology, radiology and dermatology and as a component of perceptual motor skills in medical procedures such as surgery. In 1968 the Perceptual Ability Test (PAT) was introduced in dental education. The aim of the present pilot study was to explore possible predictors of performance in diagnostic classification based on microscopic observation in the context of an undergraduate pathology course. METHODS A pre- and post-test of diagnostic classification performance, test of visual perceptual skill (Test of Visual Perceptual Skills, 3rd edition [TVPS-3]) and a self-report instrument of personality (Big Five Personality Inventory) were administered. In addition, data on academic performance (performance in histology and cell biology, a compulsory course taken the previous year, in addition to performance on the microscopy examination and final examination) were collected. RESULTS The results indicated that one personality factor (Conscientiousness) and one element of visual perceptual ability (spatial relationship awareness) predicted performance on the pre-test. The only factor to predict performance on the post-test was performance on the pre-test. Similarly, the microscopy examination score was predicted by the pre-test score, in addition to the histology and cell biology grade. The course examination score was predicted by two personality factors (Conscientiousness and lack of Openness) and the histology and cell biology grade. CONCLUSIONS Visual spatial ability may be related to performance in the initial phase of training in microscopic pathology. However, from a practical point of view, medical students are able to learn basic microscopic pathology using worked-out examples, independently of measures
Ditye, Thomas; Kanai, Ryota; Bahrami, Bahador; Muggleton, Neil G; Rees, Geraint; Walsh, Vincent
Practice-dependent changes in brain structure can occur in task relevant brain regions as a result of extensive training in complex motor tasks and long-term cognitive training but little is known about the impact of visual perceptual learning on brain structure. Here we studied the effect of five days of visual perceptual learning in a motion-color conjunction search task using anatomical MRI. We found rapid changes in gray matter volume in the right posterior superior temporal sulcus, an area sensitive to coherently moving stimuli, that predicted the degree to which an individual's performance improved with training. Furthermore, behavioral improvements were also predicted by volumetric changes in an extended white matter region underlying the visual cortex. These findings point towards quick and efficient plastic neural mechanisms that enable the visual brain to deal effectively with changing environmental demands. Copyright © 2013 Elsevier Inc. All rights reserved.
Krüger, Andreas; Edelmann-Nusser, Jürgen
This study aims at determining the accuracy of a full body inertial measurement system in a real skiing environment in comparison with an optical video based system. Recent studies have shown the use of inertial measurement systems for the determination of kinematical parameters in alpine skiing. However, a quantitative validation of a full body inertial measurement system for the application in alpine skiing is so far not available. For the purpose of this study, a skier performed a test-run equipped with a full body inertial measurement system in combination with a DGPS. In addition, one turn of the test-run was analyzed by an optical video based system. With respect to the analyzed angles, a maximum mean difference of 4.9° was measured. No differences in the measured angles between the inertial measurement system and the combined usage with a DGPS were found. Concerning the determination of the skier's trajectory, an additional system (e.g., DGPS) must be used. As opposed to optical methods, the main advantages of the inertial measurement system are the determination of kinematical parameters without the limitation of restricted capture volume, and small time costs for the measurement preparation and data analysis.
Full Text Available Introduction: Interprofessional collaboration is crucial to the optimization of patient care.Aim: This paper aims to provide recommendations for implementing an innovative constructivist educational concept with the core element of video-based self-assessment.Methodology: A course for students in medicine, physiotherapy, and nursing was developed through interprofessional, cross-institutional collaboration. The course consisted of We evaluated the preparation and implementation of the three courses conducted thus far. Concrete recommendations for implementation were made based on evaluation sheets (students, open discussions (tutors, instructors, institutions and recorded meeting minutes (project managers, project participants.Results: Basic recommendations for implementation include: selecting appropriate criteria for self-assessment and a simulated situation that offers members of each professional group an equal opportunity to act in the role play. In terms of administrative implementation we recommend early coordination among the professions and educational institutions regarding the target groups, scheduling and attendance policy to ensure participant recruitment across all professions. Procedural planning should include developing teaching materials, such as the case vignette and treatment scenario, and providing technical equipment that can be operated intuitively in order to ensure efficient recording.Conclusion: These recommendations serve as an aid for implementing an innovative constructivist educational concept with video-based self-assessment at its core.
Aghdasi, Hadi S.; Abbaspour, Maghsoud; Moghadam, Mohsen Ebrahimi; Samei, Yasaman
Technological progress in the fields of Micro Electro-Mechanical Systems (MEMS) and wireless communications and also the availability of CMOS cameras, microphones and small-scale array sensors, which may ubiquitously capture multimedia content from the field, have fostered the development of low-cost limited resources Wireless Video-based Sensor Networks (WVSN). With regards to the constraints of video-based sensor nodes and wireless sensor networks, a supporting video stream is not easy to implement with the present sensor network protocols. In this paper, a thorough architecture is presented for video transmission over WVSN called Energy-efficient and high-Quality Video transmission Architecture (EQV-Architecture). This architecture influences three layers of communication protocol stack and considers wireless video sensor nodes constraints like limited process and energy resources while video quality is preserved in the receiver side. Application, transport, and network layers are the layers in which the compression protocol, transport protocol, and routing protocol are proposed respectively, also a dropping scheme is presented in network layer. Simulation results over various environments with dissimilar conditions revealed the effectiveness of the architecture in improving the lifetime of the network as well as preserving the video quality. PMID:27873772
Dahmen, Uta; Schulze, Christine; Schindler, Claudia; Wick, Katharina; Schwartze, Dominique; Veit, Andrea; Smolenski, Ulrich
Interprofessional collaboration is crucial to the optimization of patient care. This paper aims to provide recommendations for implementing an innovative constructivist educational concept with the core element of video-based self-assessment. A course for students in medicine, physiotherapy, and nursing was developed through interprofessional, cross-institutional collaboration. The course consisted of drawing on prior knowledge about the work done by each professional group in regard to a specific clinical scenario and an interprofessional treatment situation, filming a role play of this treatment situation, and a structured self-assessment of the role play. We evaluated the preparation and implementation of the three courses conducted thus far. Concrete recommendations for implementation were made based on evaluation sheets (students), open discussions (tutors, instructors, institutions) and recorded meeting minutes (project managers, project participants). Basic recommendations for implementation include: selecting appropriate criteria for self-assessment and a simulated situation that offers members of each professional group an equal opportunity to act in the role play. In terms of administrative implementation we recommend early coordination among the professions and educational institutions regarding the target groups, scheduling and attendance policy to ensure participant recruitment across all professions. Procedural planning should include developing teaching materials, such as the case vignette and treatment scenario, and providing technical equipment that can be operated intuitively in order to ensure efficient recording. These recommendations serve as an aid for implementing an innovative constructivist educational concept with video-based self-assessment at its core.
Full Text Available Perceptual decision making in which decisions are reached primarily from extracting and evaluating sensory information requires close interactions between the sensory system and decision-related networks in the brain. Uncertainty pervades every aspect of this process and can be considered related to either the stimulus signal or decision criterion. Here, we investigated the learning-induced reduction of both the signal and criterion uncertainty in two perceptual decision tasks based on two Glass pattern stimulus sets. This was achieved by manipulating spiral angle and signal level of radial and concentric Glass patterns. The behavioral results showed that the participants trained with a task based on criterion comparison improved their categorization accuracy for both tasks, whereas the participants who were trained on a task based on signal detection improved their categorization accuracy only on their trained task. We fitted the behavioral data with a computational model that can dissociate the contribution of the signal and criterion uncertainties. The modeling results indicated that the participants trained on the criterion comparison task reduced both the criterion and signal uncertainty. By contrast, the participants who were trained on the signal detection task only reduced their signal uncertainty after training. Our results suggest that the signal uncertainty can be resolved by training participants to extract signals from noisy environments and to discriminate between clear signals, which are evidenced by reduced perception variance after both training procedures. Conversely, the criterion uncertainty can only be resolved by the training of fine discrimination. These findings demonstrate that uncertainty in perceptual decision-making can be reduced with training but that the reduction of different types of uncertainty is task-dependent.
Spruit, E.N.; Band, G.P.H.; Hamming, J.F.; Ridderinkhof, K.R.
This literature review covers the choices to consider in training complex procedural, perceptual and motor skills. In particular, we focus on laparoscopic surgery. An overview is provided of important training factors modulating the acquisition, durability, transfer, and efficiency of trained
Ulrich, Philip I N; Wilkinson, David T; Ferguson, Heather J; Smith, Laura J; Bindemann, Markus; Johnston, Robert A; Schmalzl, Laura
Developmental prosopagnosia (DP) is commonly associated with the failure to properly perceive individuating facial properties, notably those conveying configural or holistic content. While this may indicate that the primary impairment is perceptual, it is conceivable that some cases of DP are instead caused by a memory impairment, with any perceptual complaint merely allied rather than causal. To investigate this possibility, we administered a battery of face perception tasks to 11 individuals who reported that their face recognition difficulties disrupt daily activity and who also performed poorly on two formal tests of face recognition. Group statistics identified, relative to age- and gender-matched controls, difficulties in apprehending global-local relations and the holistic properties of faces, and in matching across viewpoints, but these were mild in nature and were not consistently evident at the level of individual participants. Six of the 11 individuals failed to show any evidence of perceptual impairment. In the remaining five individuals, no single perceptual deficit, or combination of deficits, was necessary or sufficient for poor recognition performance. These data suggest that some cases of DP are better explained by a memorial rather than perceptual deficit, and highlight the relevance of the apperceptive/associative distinction more commonly applied to the allied syndrome of acquired prosopagnosia.
Zhang, Hong; Li, Yuecheng; Chen, Hao; Yuan, Ding; Sun, Mingui
Recent years, although great efforts have been made to improve its performance, few Histogram equalization (HE) methods take human visual perception (HVP) into account explicitly. The human visual system (HVS) is more sensitive to edges than brightness. This paper proposes to take use of this nature intuitively and develops a perceptual contrast enhancement approach with dynamic range adjustment through histogram modification. The use of perceptual contrast connects the image enhancement problem with the HVS. To pre-condition the input image before the HE procedure is implemented, a perceptual contrast map (PCM) is constructed based on the modified Difference of Gaussian (DOG) algorithm. As a result, the contrast of the image is sharpened and high frequency noise is suppressed. A modified Clipped Histogram Equalization (CHE) is also developed which improves visual quality by automatically detecting the dynamic range of the image with improved perceptual contrast. Experimental results show that the new HE algorithm outperforms several state-of-the-art algorithms in improving perceptual contrast and enhancing details. In addition, the new algorithm is simple to implement, making it suitable for real-time applications. PMID:24339452
Ghadiyaram, Deepti; Bovik, Alan C.
Current top-performing blind perceptual image quality prediction models are generally trained on legacy databases of human quality opinion scores on synthetically distorted images. Therefore, they learn image features that effectively predict human visual quality judgments of inauthentic and usually isolated (single) distortions. However, real-world images usually contain complex composite mixtures of multiple distortions. We study the perceptually relevant natural scene statistics of such authentically distorted images in different color spaces and transform domains. We propose a “bag of feature maps” approach that avoids assumptions about the type of distortion(s) contained in an image and instead focuses on capturing consistencies—or departures therefrom—of the statistics of real-world images. Using a large database of authentically distorted images, human opinions of them, and bags of features computed on them, we train a regressor to conduct image quality prediction. We demonstrate the competence of the features toward improving automatic perceptual quality prediction by testing a learned algorithm using them on a benchmark legacy database as well as on a newly introduced distortion-realistic resource called the LIVE In the Wild Image Quality Challenge Database. We extensively evaluate the perceptual quality prediction model and algorithm and show that it is able to achieve good-quality prediction power that is better than other leading models. PMID:28129417
Lwin, Albert Thein; Lwin, Thein; Naing, Phyu; Oo, Yee; Kidd, David; Cerullo, Marcelo; Posen, Joshua; Hlaing, Kyaw; Yenokyan, Gayane; Thinn, Kyi Kyi; Soe, Zaw Wai; Stevens, Kent A
To compare self-directed interactive video-based instruction (IVBI) with instructor-led teaching in the acquisition of basic surgical skills by House Surgeons at University of Medicine 1, Yangon. A prospective, 1:1 randomized controlled trial was conducted. Participants were randomized into 2 teaching arms: (1) self-directed IVBI or (2) instructor-led teaching. Self-directed IVBI participants were provided with a portable DVD player that could play, fast forward, rewind, and skip through skills modules. Participants in the instructor-led teaching group were taught in small groups by standardized instructors. Pretesting and posttesting of 1-handed knot tie, 2-handed knot tie, vertical mattress suture, and instrument tie was performed using the Objective Structured Assessment of Technical Skills (OSATS). Students randomized to self-directed IVBI completed an exit survey to assess satisfaction. Demographic data were collected of all participants. University of Medicine 1, Yangon, Myanmar. Fifty participants were randomly selected from 78 eligible House Surgeons who were enrolled in their basic surgery rotation. Demographic characteristics and baseline skills were comparable in participants randomized to IVBI and instructor-led teaching. Mean OSATS score increased from pretest to posttest in both groups (p following statements on the exit survey: further expansion of IVBI into other skills modules and integration of IVBI into training curriculum. IVBI is noninferior to instructor-led teaching of surgical skills based on OSATS scores. House Surgeons highly rated self-directed IVBI. Self-directed IVBI has the potential to significantly reduce the personnel required for skills teaching and may serve as a long-term learning adjunct in low-resource settings. Copyright © 2017. Published by Elsevier Inc.
Schlipsing, Marc; Salmen, Jan; Tschentscher, Marc
Computer-aided sports analysis is demanded by coaches and the media. Image processing and machine learning techniques that allow for "live" recognition and tracking of players exist. But these methods are far from collecting and analyzing event data fully autonomously. To generate accurate results...... collection, annotation, and learning as an offline task. A semi-automatic labeling of training data and robust learning given few examples from unbalanced classes are required. We present a real-time system acquiring and analyzing video sequences from soccer matches. It estimates each player's position...
Suggests specific ways in which the classroom teacher can teach to a child's perceptual and instructional weakness through his strengths. Notes that the goal is to provide instruction in the subject area, not just in perceptual skills. Bibliography. (RW)
Das, V. E.; Thomas, C. W.; Zivotofsky, A. Z.; Leigh, R. J.
Video-based eye-tracking systems are especially suited to studying eye movements during naturally occurring activities such as locomotion, but eye velocity records suffer from broad band noise that is not amenable to conventional filtering methods. We evaluated the effectiveness of combined median and moving-average filters by comparing prefiltered and postfiltered records made synchronously with a video eye-tracker and the magnetic search coil technique, which is relatively noise free. Root-mean-square noise was reduced by half, without distorting the eye velocity signal. To illustrate the practical use of this technique, we studied normal subjects and patients with deficient labyrinthine function and compared their ability to hold gaze on a visual target that moved with their heads (cancellation of the vestibulo-ocular reflex). Patients and normal subjects performed similarly during active head rotation but, during locomotion, patients held their eyes more steadily on the visual target than did subjects.
Addison, Paul S; Jacquel, Dominique; Foo, David M H; Borg, Ulf R
The robust monitoring of heart rate from the video-photoplethysmogram (video-PPG) during challenging conditions requires new analysis techniques. The work reported here extends current research in this area by applying a motion tolerant algorithm to extract high quality video-PPGs from a cohort of subjects undergoing marked heart rate changes during a hypoxic challenge, and exhibiting a full range of skin pigmentation types. High uptimes in reported video-based heart rate (HRvid) were targeted, while retaining high accuracy in the results. Ten healthy volunteers were studied during a double desaturation hypoxic challenge. Video-PPGs were generated from the acquired video image stream and processed to generate heart rate. HRvid was compared to the pulse rate posted by a reference pulse oximeter device (HRp). Agreement between video-based heart rate and that provided by the pulse oximeter was as follows: Bias = - 0.21 bpm, RMSD = 2.15 bpm, least squares fit gradient = 1.00 (Pearson R = 0.99, p < 0.0001), with a 98.78% reporting uptime. The difference between the HRvid and HRp exceeded 5 and 10 bpm, for 3.59 and 0.35% of the reporting time respectively, and at no point did these differences exceed 25 bpm. Excellent agreement was found between the HRvid and HRp in a study covering the whole range of skin pigmentation types (Fitzpatrick scales I-VI), using standard room lighting and with moderate subject motion. Although promising, further work should include a larger cohort with multiple subjects per Fitzpatrick class combined with a more rigorous motion and lighting protocol.
Serpell, Benjamin G; Young, Warren B; Ford, Matthew
Agility is an open motor skill; requiring change of direction speed (CODS) and perceptual and decision-making ability. The aim of this study was to determine whether the perceptual and decision-making component of agility can be trained. Fifteen rugby league players were tested on a sport-specific reactive agility test (RAT) and a CODS test. Players were then allocated to a training group (n = 8) or a nontraining group (n = 7). The training group underwent 3 weeks of reactive agility training that was designed to enhance perceptual and decision-making ability. After 3 weeks, all players were tested again. The training group's mean reactive agility time was 1.92 ± 0.17 seconds preintervention and 1.66 ± 0.14 seconds postintervention. The nontraining group's mean reactive agility time was 1.89 ± 0.16 and 1.87 ± 0.15 seconds, respectively. Mean CODS time for the training group was 1.64 ± 0.15 seconds preintervention and 1.66 ± 0.14 seconds postintervention. The nontraining group's mean CODS time was 1.61 ± 0.12 and 1.62 ± 0.12 seconds. Mean perception and response time for the training group, measured on the RAT, was 0.33 ± 0.33 seconds preintervention and 0.04 ± 0.22 seconds postintervention. The nontraining group's values were 0.34 ± 0.20 and 0.27 ± 0.28 seconds, respectively (results are ±σ). Differences in mean reactive agility time and perception and response time from pre to postintervention for the training group were statistically significant, as were differences in those values between the training and nontraining group post intervention. All other comparisons were not. Results from this study suggest that the perceptual and decision-making components of agility are trainable. Coaches should incorporate some open motor skills training in their programs when training agility.
Horton, Jonathan C; Fahle, Manfred; Mulder, Theo; Trauzettel-Klosinski, Susanne
The capacity for functional restitution after brain damage is quite different in the sensory and motor systems. This series of presentations highlights the potential for adaptation, plasticity, and perceptual learning from an interdisciplinary perspective. The chances for restitution in the primary visual cortex are limited. Some patterns of visual field loss and recovery after stroke are common, whereas others are impossible, which can be explained by the arrangement and plasticity of the cortical map. On the other hand, compensatory mechanisms are effective, can occur spontaneously, and can be enhanced by training. In contrast to the human visual system, the motor system is highly flexible. This is based on special relationships between perception and action and between cognition and action. In addition, the healthy adult brain can learn new functions, e.g. increasing resolution above the retinal one. The significance of these studies for rehabilitation after brain damage will be discussed.
Volk, Christer Peter; Bech, Søren; Pedersen, Torben Holm
In this study the characteristics of compact loudspeakers in a stereo setup were investigated. Perceptual evaluations of eleven loudspeakers were conducted on the basis of six selected sensory descriptors, chosen by experienced listeners during consensus meetings. Based on an analysis of the perc...
Olsen, Sune L.; Agerkvist, Finn T.; MacDonald, Ewen
While non-linear distortion in loudspeakers decreases audio quality, the perceptual consequences can vary substantially. This paper investigates the metric Rnonlin  which was developed to predict subjective measurements of sound quality in nonlinear systems. The generalisability of the metric...
Pappas, Thrasyvoulos N.; Tartter, Vivien C.; Seward, Andrew G.; Genzer, Boris; Gourgey, Karen; Kretzschmar, Ilona
We propose a new approach for converting graphical and pictorial information into tactile patterns that can be displayed in a static or dynamic tactile device. The key components of the proposed approach are (1) an algorithm that segments a scene into perceptually uniform segments; (2) a procedure for generating perceptually distinct tactile patterns; and (3) a mapping of the visual textures of the segments into tactile textures that convey similar concepts. We used existing digital halftoning and other techniques to generate a wide variety of tactile textures. We then conducted formal and informal subjective tests with sighted (but visually blocked) and visually-impaired subjects to determine the ability of human tactile perception to perceive differences among them. In addition to generating perceptually distinguishable tactile patterns, our goal is to identify significant dimensions of tactile texture perception, which will make it possible to map different visual attributes into independent tactile attributes. Our experimental results indicate that it is poosible to generate a number of perceptually distinguishable tactile patterns, and that different dimensions of tactile texture perception can indeed be identified.
The purpose of this study was to determine if a perceptual-motor intervention would improve the symptoms associated with DCD. Children (N=76) with DCD between the ages of five and eight years, participated in this study. The study had a pre-/post-test experimental design (n=36) with a control group (n=40).
Troncoso, Xoana G; Macknik, Stephen L; Martinez-Conde, Susana
Artificial scotomas positioned within peripheral dynamic noise fade perceptually during visual fixation (that is, the surrounding dynamic noise appears to fill-in the scotoma). Because the scotomas' edges are continuously refreshed by the dynamic noise background, this filling-in effect cannot be explained by low-level adaptation mechanisms (such as those that may underlie classical Troxler fading). We recently showed that microsaccades counteract Troxler fading and drive first-order visibility during fixation (S. Martinez-Conde, S. L. Macknik, X. G. Troncoso, & T. A. Dyar, 2006). Here we set out to determine whether microsaccades may counteract the perceptual filling-in of artificial scotomas and thus drive second-order visibility. If so, microsaccades may not only counteract low-level adaptation but also play a role in higher perceptual processes. We asked subjects to indicate, via button press/release, whether an artificial scotoma presented on a dynamic noise background was visible or invisible at any given time. The subjects' eye movements were simultaneously measured with a high precision video system. We found that increases in microsaccade production counteracted the perception of filling-in, driving the visibility of the artificial scotoma. Conversely, decreased microsaccades allowed perceptual filling-in to take place. Our results show that microsaccades do not solely overcome low-level adaptation mechanisms but they also contribute to maintaining second-order visibility during fixation.
Lamata, Pablo; Gomez, Enrique J; Hernández, Félix Lamata; Oltra Pastor, Alfonso; Sanchez-Margallo, Francisco Miquel; Del Pozo Guerrero, Francisco
Human perceptual capabilities related to the laparoscopic interaction paradigm are not well known. Its study is important for the design of virtual reality simulators, and for the specification of augmented reality applications that overcome current limitations and provide a supersensing to the surgeon. As part of this work, this article addresses the study of laparoscopic pulling forces. Two definitions are proposed to focalize the problem: the perceptual fidelity boundary, limit of human perceptual capabilities, and the Utile fidelity boundary, that encapsulates the perceived aspects actually used by surgeons to guide an operation. The study is then aimed to define the perceptual fidelity boundary of laparoscopic pulling forces. This is approached with an experimental design in which surgeons assess the resistance against pulling of four different tissues, which are characterized with both in vivo interaction forces and ex vivo tissue biomechanical properties. A logarithmic law of tissue consistency perception is found comparing subjective valorizations with objective parameters. A model of this perception is developed identifying what the main parameters are: the grade of fixation of the organ, the tissue stiffness, the amount of tissue bitten, and the organ mass being pulled. These results are a clear requirement analysis for the force feedback algorithm of a virtual reality laparoscopic simulator. Finally, some discussion is raised about the suitability of augmented reality applications around this surgical gesture.
Auvray, Malika; Rohde, Marieke
Researchers in social cognition increasingly realize that many phenomena cannot be understood by investigating offline situations only, focusing on individual mechanisms and an observer perspective. There are processes of dynamic emergence specific to online situations, when two or more persons are engaged in a real-time interaction that are more than just the sum of the individual capacities or behaviors, and these require the study of online social interaction. Auvray et al.'s (2009) perceptual crossing paradigm offers possibly the simplest paradigm for studying such online interactions: two persons, a one-dimensional space, one bit of information, and a yes/no answer. This study has provoked a lot of resonance in different areas of research, including experimental psychology, computer/robot modeling, philosophy, psychopathology, and even in the field of design. In this article, we review and critically assess this body of literature. We give an overview of both behavioral experimental research and simulated agent modeling done using the perceptual crossing paradigm. We discuss different contexts in which work on perceptual crossing has been cited. This includes the controversy about the possible constitutive role of perceptual crossing for social cognition. We conclude with an outlook on future research possibilities, in particular those that could elucidate the link between online interaction dynamics and individual social cognition. PMID:22723776
Toet, A.; IJspeert, J.K.
Human perceptual performance was tested with images of nighttime outdoor scenes. The scenes were registered both with a dual band (visual and near infrared) image intensified low-light CCD camera (DII) and with a thermal middle wavelength band (3-5 μm) infrared (IR) camera. Fused imagery was
Research is reviewed on eye movements during reading, on the perceptual span and control of eye movements during normal reading, and on the nature of eye movements in dyslexia. Rather than the cause of dyslexia, eye movements are said to reflect underlying cognitive or neurological problems. (CL)
Overvliet, K.E.; Sayim, B.
Since the early phenomenological demonstrations of Gestalt principles, one of the major challenges of Gestalt psychology has been to quantify these principles. Here, we show that contextual modulation, i.e. the influence of context on target perception, can be used as a tool to quantify perceptual
Overvliet, K. E.; Sayim, B.
Since the early phenomenological demonstrations of Gestalt principles, one of the major challenges of Gestalt psychology has been to quantify these principles. Here, we show that contextual modulation, i.e. the influence of context on target perception, can be used as a tool to quantify perceptual
Sanes, Dan H.
Sensory pathways display heightened plasticity during development, yet the perceptual consequences of early experience are generally assessed in adulthood. This approach does not allow one to identify transient perceptual changes that may be linked to the central plasticity observed in juvenile animals. Here, we determined whether a brief period of bilateral auditory deprivation affects sound perception in developing and adult gerbils. Animals were reared with bilateral earplugs, either from postnatal day 11 (P11) to postnatal day 23 (P23) (a manipulation previously found to disrupt gerbil cortical properties), or from P23-P35. Fifteen days after earplug removal and restoration of normal thresholds, animals were tested on their ability to detect the presence of amplitude modulation (AM), a temporal cue that supports vocal communication. Animals reared with earplugs from P11-P23 displayed elevated AM detection thresholds, compared with age-matched controls. In contrast, an identical period of earplug rearing at a later age (P23-P35) did not impair auditory perception. Although the AM thresholds of earplug-reared juveniles improved during a week of repeated testing, a subset of juveniles continued to display a perceptual deficit. Furthermore, although the perceptual deficits induced by transient earplug rearing had resolved for most animals by adulthood, a subset of adults displayed impaired performance. Control experiments indicated that earplugging did not disrupt the integrity of the auditory periphery. Together, our results suggest that P11-P23 encompasses a critical period during which sensory deprivation disrupts central mechanisms that support auditory perceptual skills. SIGNIFICANCE STATEMENT Sensory systems are particularly malleable during development. This heightened degree of plasticity is beneficial because it enables the acquisition of complex skills, such as music or language. However, this plasticity comes with a cost: nervous system development
Su, Yuling; Lai, Yunpeng; Huang, Wanyi; Tan, Wei; Qu, Zhe; Ding, Yulong
Although some studies showed that training can improve the ability of cross-dimension conjunction search, less is known about the underlying mechanism. Specifically, it remains unclear whether training of visual conjunction search can successfully bind different features of separated dimensions into a new function unit at early stages of visual processing. In the present study, we utilized stimulus specificity and generalization to provide a new approach to investigate the mechanisms underlying perceptual learning (PL) in visual conjunction search. Five experiments consistently showed that after 40 to 50 min of training of color-shape/orientation conjunction search, the ability to search for a certain conjunction target improved significantly and the learning effects did not transfer to a new target that differed from the trained target in both color and shape/orientation features. However, the learning effects were not strictly specific. In color-shape conjunction search, although the learning effect could not transfer to a same-shape different-color target, it almost completely transferred to a same-color different-shape target. In color-orientation conjunction search, the learning effect partly transferred to a new target that shared same color or same orientation with the trained target. Moreover, the sum of transfer effects for the same color target and the same orientation target in color-orientation conjunction search was algebraically equivalent to the learning effect for trained target, showing an additive transfer effect. The different transfer patterns in color-shape and color-orientation conjunction search learning might reflect the different complexity and discriminability between feature dimensions. These results suggested a feature-based attention enhancement mechanism rather than a unitization mechanism underlying the short-term PL of color-shape/orientation conjunction search.
Zhang, Gong-Liang; Li, Hao; Song, Yan; Yu, Cong
The brain site of perceptual learning has been frequently debated. Recent psychophysical evidence for complete learning transfer to new retinal locations and orientations/directions suggests that perceptual learning may mainly occur in high-level brain areas. Contradictorily, ERP C1 changes associated with perceptual learning are cited as evidence for training-induced plasticity in the early visual cortex. However, C1 can be top-down modulated, which suggests the possibility that C1 changes may result from top-down modulation of the early visual cortex by high-level perceptual learning. To single out the potential top-down impact, we trained observers with a peripheral orientation discrimination task and measured C1 changes at an untrained diagonal quadrant location where learning transfer was previously known to be significant. Our assumption was that any C1 changes at this untrained location would indicate top-down modulation of the early visual cortex, rather than plasticity in the early visual cortex. The expected learning transfer was indeed accompanied with significant C1 changes. Moreover, C1 changes were absent in an untrained shape discrimination task with the same stimuli. We conclude that ERP C1 can be top-down modulated in a task-specific manner by high-level perceptual learning, so that C1 changes may not necessarily indicate plasticity in the early visual cortex. Moreover, learning transfer and associated C1 changes may indicate that learning-based top-down modulation can be remapped to early visual cortical neurons at untrained locations to enable learning transfer.
Butler, Pamela D; Thompson, Judy L; Seitz, Aaron R; Deveau, Jenni; Silverstein, Steven M
Few studies have evaluated the effects of visual remediation strategies in schizophrenia despite abundant evidence of visual-processing alterations in this condition. We report preliminary, case-study-based evidence regarding the effects of visual remediation in this population. We describe implementation of a visual-perceptual training program called ULTIMEYES (UE) and initial results through 3 brief case studies of individuals with schizophrenia. UE targets broad-based visual function, including low-level processes (e.g., acuity, contrast sensitivity) as well as higher level visual functions. Three inpatients, recruited from a research unit, participated in at least 38 sessions 3 to 4 times per week for approximately 25 min per session. Contrast sensitivity (a trained task), as well as acuity and perceptual organization (untrained tasks), were assessed before and after the intervention. Levels of progression through the task are also reported. UE was well tolerated by the participants and led to improvements in contrast sensitivity, as well as more generalized gains in visual acuity in all 3 participants and perceptual organization in 2 participants. Symptom profiles were somewhat different for each participant, but all were symptomatic during the intervention. Despite this, they were able to focus on and benefit from training. The adaptive nature of the training was well suited to the slower progression of 2 participants. These case studies set the stage for further research, such as larger, randomized controlled trials of the intervention that include additional assessments of perceptual function and measures of cognition, social cognition, and functional outcomes. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Yin Ping Ng
Full Text Available Mental illness-related stigma is common, and is associated with poorer outcomes in people with mental illness. This study evaluated the attitudes of primary care nurses towards people with mental illness and its associated factors; and the effectiveness of a short video-based contact intervention (VBCI in improving these attitudes using a Malay version of the 15-item Opening Minds Stigma Scale for Healthcare Providers (OMS-HC-15-M.A 5-minute VBCI was developed comprising elements of psychoeducation and interviews of people with mental illness and the people they interact with, relating to experience of mental illness and recovery. A pre-post cross-sectional study was conducted on 206 randomly selected primary care nurses in Penang, Malaysia. The OMS-HC-15-M questionnaire was administered before and immediately after participants viewed the VBCI. The difference in mean pre-post VBCI scores using paired t-tests, effect size and standardised response mean (SRM were obtained. Factors correlating to attitudes were obtained using univariate and multivariate regression analyses.Differences in pre-post VBCI score were statistically significant (p<0.001 with a 14% score reduction, a moderate effect size and SRM at 0.97 (0.85-0.11 and 1.1 (0.97-1.2 respectively. By factoring in the Minimal Detectable Change statistic of 7.76, the VBCI produced a significant improvement of attitudes in 30% of the participants. Factors associated with less stigmatising attitudes at baseline were previous psychiatry-related training, desiring psychiatric training, and positive contact with people with mental illness.This is the first study in Malaysia to show that a brief VBCI is effective in improving attitudes of primary care nurses towards people with mental illness in the immediate term. Further studies are needed to determine if these results can be sustained in the longer term and generalizable to other health care professionals. Qualitative studies are warranted to
Aravamudhan, Radhika; Lotto, Andrew J; Hawks, John W
Williams [(1986). "Role of dynamic information in the perception of coarticulated vowels," Ph.D. thesis, University of Connecticut, Standford, CT] demonstrated that nonspeech contexts had no influence on pitch judgments of nonspeech targets, whereas context effects were obtained when instructed to perceive the sounds as speech. On the other hand, Holt et al. [(2000). "Neighboring spectral content influences vowel identification," J. Acoust. Soc. Am. 108, 710-722] showed that nonspeech contexts were sufficient to elicit context effects in speech targets. The current study was to test a hypothesis that could explain the varying effectiveness of nonspeech contexts: Context effects are obtained only when there are well-established perceptual categories for the target stimuli. Experiment 1 examined context effects in speech and nonspeech signals using four series of stimuli: steady-state vowels that perceptually spanned from /inverted ohm/-/I/ in isolation and in the context of /w/ (with no steady-state portion) and two nonspeech sine-wave series that mimicked the acoustics of the speech series. In agreement with previous work context effects were obtained for speech contexts and targets but not for nonspeech analogs. Experiment 2 tested predictions of the hypothesis by testing for nonspeech context effects after the listeners had been trained to categorize the sounds. Following training, context-dependent categorization was obtained for nonspeech stimuli in the training group. These results are presented within a general perceptual-cognitive framework for speech perception research.
van Ravenzwaaij, Don; Boekel, Wouter; Forstmann, Birte U.; Ratcliff, Roger; Wagenmakers, Eric-Jan
Previous research suggests that playing action video games improves performance on sensory, perceptual, and attentional tasks. For instance, Green, Pouget, and Bavelier (2010) used the diffusion model to decompose data from a motion detection task and estimate the contribution of several underlying psychological processes. Their analysis indicated that playing action video games leads to faster information processing, reduced response caution, and no difference in motor responding. Because perceptual learning is generally thought to be highly context-specific, this transfer from gaming is surprising and warrants corroborative evidence from a large-scale training study. We conducted 2 experiments in which participants practiced either an action video game or a cognitive game in 5 separate, supervised sessions. Prior to each session and following the last session, participants performed a perceptual discrimination task. In the second experiment, we included a third condition in which no video games were played at all. Behavioral data and diffusion model parameters showed similar practice effects for the action gamers, the cognitive gamers, and the nongamers and suggest that, in contrast to earlier reports, playing action video games does not improve the speed of information processing in simple perceptual tasks. PMID:24933517
van Ravenzwaaij, Don; Boekel, Wouter; Forstmann, Birte U; Ratcliff, Roger; Wagenmakers, Eric-Jan
Previous research suggests that playing action video games improves performance on sensory, perceptual, and attentional tasks. For instance, Green, Pouget, and Bavelier (2010) used the diffusion model to decompose data from a motion detection task and estimate the contribution of several underlying psychological processes. Their analysis indicated that playing action video games leads to faster information processing, reduced response caution, and no difference in motor responding. Because perceptual learning is generally thought to be highly context-specific, this transfer from gaming is surprising and warrants corroborative evidence from a large-scale training study. We conducted 2 experiments in which participants practiced either an action video game or a cognitive game in 5 separate, supervised sessions. Prior to each session and following the last session, participants performed a perceptual discrimination task. In the second experiment, we included a third condition in which no video games were played at all. Behavioral data and diffusion model parameters showed similar practice effects for the action gamers, the cognitive gamers, and the nongamers and suggest that, in contrast to earlier reports, playing action video games does not improve the speed of information processing in simple perceptual tasks.
Wiens, Peter D.; Hessberg, Kevin; LoCasale-Crouch, Jennifer; DeCoster, Jamie
The Video Assessment of Interactions and Learning (VAIL), a video-based assessment of teacher understanding of effective teaching strategies and behaviors, was administered to preservice teachers. Descriptive and regression analyzes were conducted to examine trends among participants and identify predictors at the individual level and program…
Hung, Yu-Wan; Higgins, Steve
This study investigates the different learning opportunities enabled by text-based and video-based synchronous computer-mediated communication (SCMC) from an interactionist perspective. Six Chinese-speaking learners of English and six English-speaking learners of Chinese were paired up as tandem (reciprocal) learning dyads. Each dyad participated…
L.A.L. de Meijer (Lonneke); M.Ph. Born (Marise); J. van Zielst (Jaap); H.T. van der Molen (Henk)
textabstractIn a field study conducted in a multi-ethnic selection setting at the Dutch police, we examined the construct validity of a video-based situational judgment test (SJT) aimed to measure the construct of integrity. Integrity is of central importance to productive work performance of police
Park, Sung Youl; Kim, Soo-Wook; Cha, Seung-Bong; Nam, Min-Woo
This study investigated the effectiveness of e-learning by comparing the learning outcomes in conventional face-to-face lectures and e-learning methods. Two video-based e-learning contents were developed based on the rapid prototyping model and loaded onto the learning management system (LMS), which was available at http://www.greenehrd.com.…
Koleza, Eugenia; Pappas, John
In this article, we present the results of a qualitative research project on the effect of motion analysis activities in a Video-Based Laboratory (VBL) on students' understanding of position, velocity and frames of reference. The participants in our research were 48 pre-service teachers enrolled in Education Departments with no previous strong…
Gambari, Amosa Isiaka; Shittu, Ahmed Tajudeen; Daramola, Florence Olutunu; James, Moses
This study examined the effects of video-based cooperative, competitive and individualized instructional strategies on the performance of senior secondary schools' students in geometry in Nigeria. It also examined the influence of gender on students' achievement. Pretest, posttest, experimental control group design was adopted for this study.…
Walsh-Buhi, Eric R.; Helmy, Hannah; Harsch, Kristin; Rella, Natalie; Godcharles, Cheryl; Ogunrunde, Adejoke; Lopez Castillo, Humberto
Objective: This paper reports on a pilot study evaluating the feasibility and acceptability of a text- and mobile video-based intervention to educate women and men attending college about non-daily contraception, with a particular focus on long-acting reversible contraception (LARC). A secondary objective is to describe the process of intervention…
Investigating how visuals affect test takers' performance on video-based L2 listening tests has been the focus of many recent studies. While most existing research has been based on test scores and self-reported verbal data, few studies have examined test takers' viewing behavior (Ockey, 2007; Wagner, 2007, 2010a). To address this gap, in the…
Rothen, Nicolas; Schwartzman, David J; Bor, Daniel; Seth, Anil K
Synesthesia is associated with additional perceptual experiences, which are automatically and consistently triggered by specific inducing stimuli. Synesthesia is also accompanied by more general sensory and cortical changes, including enhanced modality-specific cortical excitability. Extensive cognitive training has been shown to generate synesthesia-like phenomenology but whether these experiences are accompanied by neurophysiological changes characteristic of synesthesia remains unknown. Addressing this question provides a unique opportunity to elucidate the neural basis of perceptual plasticity relevant to conscious experiences. Here we investigate whether extensive training of letter-color associations leads not only to synesthetic experiences, but also to changes in cortical excitability. We confirm that overtraining synesthetic associations results in synesthetic phenomenology. Stroop tasks further reveal synesthesia-like performance following training. Electroencephalography and transcranial magnetic stimulation show, respectively, enhanced visual evoked potentials (in response to untrained patterns) and lower phosphene thresholds, demonstrating specific cortical changes. An active (using letter-symbol training) and a passive control confirmed these results were due to letter-color training and not simply to repeated testing. Summarizing, we demonstrate specific cortical changes, following training-induced acquisition of synesthetic phenomenology that are characteristic of genuine synesthesia. Collectively, our data reveal dramatic plasticity in human visual perception, expressed through a coordinated set of behavioral, neurophysiological, and phenomenological changes. Copyright © 2018 Elsevier Ltd. All rights reserved.
Full Text Available Human sound localization abilities rely on binaural and spectral cues. Spectral cues arise from interactions between the sound wave and the listener’s body (head related transfer function, HRTF. Large individual differences were reported in localization abilities, even in young normal-hearing adults. Several studies have attempted to determine whether localization abilities depend mostly on acoustic cues or on perceptual processes involved in the analysis of these cues. These studies have yielded inconsistent findings, which could result from methodological issues. Here, we measured sound localization performance with normal and modified acoustic cues (i.e., with individual and non-individual HRTFs, respectively in 20 naïve listeners. Test conditions were chosen to address most methodological issues from past studies. Procedural training was provided prior to sound localization tests. The results showed no direct relationship between behavioral results and an acoustical metric (spectral-shape prominence of individual HRTFs. Despite uncertainties due to technical issues with the normalization of the HRTFs, large acoustic differences between individual and non-individual HRTFs seemed to be needed to produce behavioral effects. A subset of 15 listeners then trained in the sound localization task with individual HRTFs. Training included either visual correct-answer feedback (for the test group or no feedback (for the control group, and was assumed to elicit perceptual learning for the test group only. Few listeners from the control group, but most listeners from the test group, showed significant training-induced learning. For the test group, learning was related to pre-training performance (the poorer the pre-training performance, the greater the learning amount and was retained after one month.The results are interpreted as being in favor of a larger contribution of perceptual factors than of acoustic factors to sound localization abilities
Wendt, Mike; Luna-Rodriguez, Aquiles; Kiesel, Andrea; Jacobsen, Thomas
Task performance suffers when an aspect of a stimulus is associated with an incorrect response, thereby evoking cognitive conflict. Such impairment is reduced after recent or frequent conflict occurrence, suggesting attentional adjustment. We examined adjustment to conflict evoked by a temporarily irrelevant S-R rule when participants frequently switched between two semantic classification tasks by manipulating the proportion of conflict trials in one of them. Controlling stimulus-specific presentation frequencies, we found reduced conflict effects under conditions of a higher proportion of conflict trials in the task to which the manipulation was applied, whereas there was no such effect in the other task. Additional analyses demonstrated task-specificity regarding trial-to-trial conflict adjustment. Because conflict was evoked in the absence of perceptually distinct target and distractor stimulus features, these adjustment effects cannot be attributed to perceptual selection. Copyright © 2013 Elsevier B.V. All rights reserved.
Wardle, Susan G; Carlson, Thomas A
The human visual system is usually very successful in segmenting complex natural scenes. During a trip to the Nepalese Himalayas, we observed an impossible example of Nature's beauty: "transparent" mountains. The scene is captured in a photograph in which a pair of mountain peaks viewed in the far distance appear to be transparent. This illusion results from a fortuitous combination of lighting and scene conditions, which induce an erroneous integration of multiple segmentation cues. The illusion unites three classic principles of visual perception: Metelli's constraints for perceptual transparency, the Gestalt principle of good continuation, and depth from contrast and atmospheric scattering. This real-world "failure" of scene segmentation reinforces how ingeniously the human visual system typically integrates complex sources of perceptual information using heuristics based on likelihood as shortcuts to veridical perception.
Marta I Garrido
Full Text Available Surprising events in the environment can impair task performance. This might be due to complete distraction, leading to lapses during which performance is reduced to guessing. Alternatively, unpredictability might cause a graded withdrawal of perceptual resources from the task at hand and thereby reduce sensitivity. Here we attempt to distinguish between these two mechanisms. Listeners performed a novel auditory pitch—duration discrimination, where stimulus loudness changed occasionally and incidentally to the task. Responses were slower and less accurate in the surprising condition, where loudness changed unpredictably, than in the predictable condition, where the loudness was held constant. By explicitly modelling both lapses and changes in sensitivity, we found that unpredictable changes diminished sensitivity but did not increase the rate of lapses. These findings suggest that background environmental uncertainty can disrupt goal-directed behaviour. This graded processing strategy might be adaptive in potentially threatening contexts, and reflect a flexible system for automatic allocation of perceptual resources.
Kee, Eric; Farid, Hany
In recent years, advertisers and magazine editors have been widely criticized for taking digital photo retouching to an extreme. Impossibly thin, tall, and wrinkle- and blemish-free models are routinely splashed onto billboards, advertisements, and magazine covers. The ubiquity of these unrealistic and highly idealized images has been linked to eating disorders and body image dissatisfaction in men, women, and children. In response, several countries have considered legislating the labeling of retouched photos. We describe a quantitative and perceptually meaningful metric of photo retouching. Photographs are rated on the degree to which they have been digitally altered by explicitly modeling and estimating geometric and photometric changes. This metric correlates well with perceptual judgments of photo retouching and can be used to objectively judge by how much a retouched photo has strayed from reality.
Susan G. Wardle
Full Text Available The human visual system is usually very successful in segmenting complex natural scenes. During a trip to the Nepalese Himalayas, we observed an impossible example of Nature's beauty: “transparent” mountains. The scene is captured in a photograph in which a pair of mountain peaks viewed in the far distance appear to be transparent. This illusion results from a fortuitous combination of lighting and scene conditions, which induce an erroneous integration of multiple segmentation cues. The illusion unites three classic principles of visual perception: Metelli's constraints for perceptual transparency, the Gestalt principle of good continuation, and depth from contrast and atmospheric scattering. This real-world “failure” of scene segmentation reinforces how ingeniously the human visual system typically integrates complex sources of perceptual information using heuristics based on likelihood as shortcuts to veridical perception.
Full Text Available Work aimed at studying social cognition in an interactionist perspective often encounters substantial theoretical and methodological difficulties: identifying the significant behavioural variables; recording them without disturbing the interaction; and distinguishing between:(a the necessary and sufficient contributions of each individual partner for a collective dynamics to emerge ;(b features which derive from this collective dynamics and escape from the control of the individual partners ;(c the phenomena arising from this collective dynamics which are subsequently appropriated and used by the partners.We propose a minimalist experimental paradigm as a basis for this conceptual discussion: by reducing the sensory inputs to a strict minimum, we force a spatial and temporal deployment of the perceptual activities, which makes it possible to obtain a complete recording and control of the dynamics of interaction. After presenting the principles of this minimalist approach to perception, we describe a series of experiments on two major questions in social cognition: recognizing the presence of another intentional subject; and phenomena of imitation. In both cases, we propose explanatory schema which render an interactionist approach to social cognition clear and explicit.Starting from our earlier work on perceptual crossing we present a new experiment on the mechanisms of reciprocal recognition of the perceptual intentionality of the other subject: the emergent collective dynamics of the perceptual crossing can be appropriated by each subject. We then present an experimental study of opaque imitation (when the subjects cannot see what they themselves are doing. This study makes it possible to characterize what a properly interactionist approach to imitation might be. In conclusion, we draw on these results, to show how an interactionist approach can contribute to a fully social approach to social cognition.
Keller, E; Rothenberger, A; Göpfert, M
In the present study 3 hypotheses were investigated: first, the notion that an aphasic impairment of vowel perception is not associated with particular aphasic syndromes or lesion sites, second, that it is a disorder comparable to a general impairment of perception in a normal speaker caused by some form of interference, and third, that perceptual phonemic discrimination is a separate process from the phonemic discriminative function necessary for speech production. The hypotheses were tested by means of a vowel discrimination test administered to 50 German-speaking aphasic patients (roughly equally divided between Broca's, mixed non-fluent, Wernicke's and mixed fluent groups); the same test, masked by white noise at -10 dB was also administered to 20 normal native speakers of German. Results were in support of all 3 hypotheses. First, aphasic patients' error patterns were similar across fluent and nonfluent groups and for all lesion sites. Second, the error distributions of aphasics with slight auditory impairment resembled those of normal subjects in the -10 dB white noise condition, while distributions of aphasics with severe auditory impairment were indicative of an added component of guessing behaviour. And third, the patients' performance on the discrimination task differed from that shown on a comparable repetition test. (It was argued that repetition involves a patient's expressive capacity in addition to his perceptual capacity). The differentiation of perceptual and expressive phonemic discrimination was further supported by an analysis of the speech errors occurring in the spontaneous (purely expressive) speech and in the repetition (expressive plus perceptual) tasks of 16 French Canadian and 5 English Canadian aphasics.
the input syllabic rhythm; the frequencies and relative phases of the oscillations determine the processing time frames that control the decoding...entirely on phonetic and syllabic decoding devoid of meaning. This narrow focus makes it difficult to link the perceptual data displayed in Ghitza...and that there is a huge range of variation in intrinsic decoding ability, depending on the phonetic, syllabic and syntactic properties of individual
Visual perception is a complex process requiring interaction between the receptors in the eye that sense the stimulus and the neural system and the brain that are responsible for communicating and interpreting the sensed visual information. This process involves several physical, neural, and cognitive phenomena whose understanding is essential to design effective and computationally efficient imaging solutions. Building on advances in computer vision, image and video processing, neuroscience, and information engineering, perceptual digital imaging greatly enhances the capabilities of tradition
Astle, Andrew T.; Webb, Ben S.; McGraw, Paul V.
Background Amblyopia presents early in childhood and affects approximately 3% of western populations. The monocular visual acuity loss is conventionally treated during the “critical periods” of visual development by occluding or penalising the fellow eye to encourage use of the amblyopic eye. Despite the measurable success of this approach in many children, substantial numbers of people still suffer with amblyopia later in life because either they were never diagnosed in childhood, did not respond to the original treatment, the amblyopia was only partially remediated, or their acuity loss returned after cessation of treatment. Purpose In this review, we consider whether the visual deficits of this largely overlooked amblyopic group are amenable to conventional and innovative therapeutic interventions later in life, well beyond the age at which treatment is thought to be effective. Recent findings There is a considerable body of evidence that residual plasticity is present in the adult visual brain and this can be harnessed to improve function in adults with amblyopia. Perceptual training protocols have been developed to optimise visual gains in this clinical population. Results thus far are extremely encouraging: marked visual improvements have been demonstrated, the perceptual benefits transfer to new visual tasks and appear to be relatively enduring. The essential ingredients of perceptual training protocols are being incorporated into video game formats, facilitating home-based interventions. Summary Many studies support perceptual training as a tool for improving vision in amblyopes beyond the critical period. Should this novel form of treatment stand up to the scrutiny of a randomised controlled trial, clinicians may need to re-evaluate their therapeutic approach to adults with amblyopia. PMID:21981034
Heinrich, S P
The idea of compensating or even rectifying refractive errors and presbyopia with the help of vision training is not new. For most approaches, however, scientific evidence is insufficient. A currently promoted method is "perceptual learning", which is assumed to improve stimulus processing in the brain. The basic phenomena of perceptual learning have been demonstrated by a multitude of studies. Some of these specifically address the case of refractive errors and presbyopia. However, many open questions remain, in particular with respect to the transfer of practice effects to every-day vision. At present, the method should therefore be judged with caution.
Full Text Available Inferring causality is a fundamental feature of human cognition that allows us to theorize about and predict future states of the world. Michotte suggested that humans automatically perceive causality based on certain perceptual features of events. However, individual differences in judgments of perceptual causality cast doubt on Michotte’s view. To gain insights in the neural basis of individual difference in the perception of causality, our participants judged causal relationships in animations of a blue ball colliding with a red ball (a launching event while fMRI-data were acquired. Spatial continuity and temporal contiguity were varied parametrically in these stimuli. We did not find consistent brain activation differences between trials judged as caused and those judged as non-caused, making it unlikely that humans have universal instantiation of perceptual causality in the brain. However, participants were slower to respond to and showed greater neural activity for violations of causality, suggesting that humans are biased to expect causal relationships when moving objects appear to interact. Our participants demonstrated considerable individual differences in their sensitivity to spatial and temporal characteristics in perceiving causality. These qualitative differences in sensitivity to time or space in perceiving causality were instantiated in individual differences in activation of the left basal ganglia or right parietal lobe, respectively. Thus, the perception that the movement of one object causes the movement of another is triggered by elemental spatial and temporal sensitivities, which themselves are instantiated in specific distinct neural networks.
Full Text Available Absolute pitch (AP is the rare ability of musicians to identify the pitch of tonal sound without external reference. While there have been behavioral and neuroimaging studies on the characteristics of AP, how the AP is implemented in human brains remains largely unknown. AP can be viewed as comprising of two subprocesses: perceptual (processing auditory input to extract a pitch chroma and associative (linking an auditory representation of pitch chroma with a verbal/non-verbal label. In this review, we focus on the nature of the perceptual subprocess of AP. Two different models on how the perceptual subprocess works have been proposed: either via absolute pitch categorization (APC or based on absolute pitch memory (APM. A major distinction between the two views is that whether the AP uses unique auditory processing (i.e., APC that exists only in musicians with AP or it is rooted in a common phenomenon (i.e., APM, only with heightened efficiency. We review relevant behavioral and neuroimaging evidence that supports each notion. Lastly, we list open questions and potential ideas to address them.
Full Text Available Researchers in social cognition increasingly realize that many phenomena cannot be understood by investigating offline situations only, focusing on individual mechanisms and an observer perspective. There are processes of dynamic emergence specific to online situations, when two or more persons are engaged in a real-time interaction that are more than just the sum of the individual capacities or behaviours, and these require the study of online social interaction. Auvray et al.’s (2009 perceptual crossing paradigm offers possibly the simplest paradigm for studying such online interactions: two persons, a one-dimensional space, one bit of information, and a yes/no answer. Despite, or maybe because of its simplicity, this study has provoked a lot of resonance in different areas of research, including experimental psychology, computer/robot modelling, philosophy, more recently psychopathology, and even in the field of design. In this article, we review and critically assess this body of literature. We give an overview over work on the perceptual crossing paradigm, both concerning behavioural experiments and computational agent modelling, and review the different contexts in which it has been referred to. We discuss the controversy about the possible constitutive role of perceptual crossing for social cognition and other theoretical contexts in which the research has been cited, offering our own interpretation. We conclude with an outlook on future research possibilities, in particular those that could elucidate the link between online interaction dynamics and individual social cognition.
Yang, Huan; Fang, Yuming; Lin, Weisi
Research on screen content images (SCIs) becomes important as they are increasingly used in multi-device communication applications. In this paper, we present a study on perceptual quality assessment of distorted SCIs subjectively and objectively. We construct a large-scale screen image quality assessment database (SIQAD) consisting of 20 source and 980 distorted SCIs. In order to get the subjective quality scores and investigate, which part (text or picture) contributes more to the overall visual quality, the single stimulus methodology with 11 point numerical scale is employed to obtain three kinds of subjective scores corresponding to the entire, textual, and pictorial regions, respectively. According to the analysis of subjective data, we propose a weighting strategy to account for the correlation among these three kinds of subjective scores. Furthermore, we design an objective metric to measure the visual quality of distorted SCIs by considering the visual difference of textual and pictorial regions. The experimental results demonstrate that the proposed SCI perceptual quality assessment scheme, consisting of the objective metric and the weighting strategy, can achieve better performance than 11 state-of-the-art IQA methods. To the best of our knowledge, the SIQAD is the first large-scale database published for quality evaluation of SCIs, and this research is the first attempt to explore the perceptual quality assessment of distorted SCIs.
Plack, Christopher J; Barker, Daphne; Prendergast, Garreth
Dramatic results from recent animal experiments show that noise exposure can cause a selective loss of high-threshold auditory nerve fibers without affecting absolute sensitivity permanently. This cochlear neuropathy has been described as hidden hearing loss, as it is not thought to be detectable using standard measures of audiometric threshold. It is possible that hidden hearing loss is a common condition in humans and may underlie some of the perceptual deficits experienced by people with clinically normal hearing. There is some evidence that a history of noise exposure is associated with difficulties in speech discrimination and temporal processing, even in the absence of any audiometric loss. There is also evidence that the tinnitus experienced by listeners with clinically normal hearing is associated with cochlear neuropathy, as measured using Wave I of the auditory brainstem response. To date, however, there has been no direct link made between noise exposure, cochlear neuropathy, and perceptual difficulties. Animal experiments also reveal that the aging process itself, in the absence of significant noise exposure, is associated with loss of auditory nerve fibers. Evidence from human temporal bone studies and auditory brainstem response measures suggests that this form of hidden loss is common in humans and may have perceptual consequences, in particular, regarding the coding of the temporal aspects of sounds. Hidden hearing loss is potentially a major health issue, and investigations are ongoing to identify the causes and consequences of this troubling condition. © The Author(s) 2014.
Full Text Available Healthy individuals tend to weigh in more the left than the right side of visual space in a variety of contexts, ranging from pseudoneglect to perceptual asymmetries for faces. Among the common explanations proposed for the attentional and perceptual advantages of the left visual field, a link with the prevalence of right-handedness in humans has never been suggested, although some evidence seems to converge in favor of a bias of spatial attention towards the region most likely coincident with another person’s right hand during a face-to-face interaction. Such a bias might imply an increased efficiency in monitoring both communicative and aggressive acts, the right limb being more used than the left in both types of behaviour. Although attentional and perceptual asymmetries could be linked to right-handedness at the level of phylogeny because of the evolutionarily advantage of directing attention towards the region where others’ dominant hand usually operates, it is also legitimate to question whether, at the ontogenetic level, frequent exposure to right-handed individuals may foster leftward biases. These views are discussed in the light of extant literature, and a number of tests are proposed in order to assess our hypotheses.
Gordon, Matthew; Jany, Carmen; Nash, Carlos
Differences between languages in the stress-attracting properties of various syllable types (syllable weight) are associated with phonetic differences. Certain languages that preferentially stress CVC syllables (i.e., treat CVC as heavy) fail to display substantial vowel shortening in CVC, unlike languages that treat CVC as non-stress-attracting or light [Broselow et al. (1997)]. Furthermore, CVC has greater energy (intensity integrated over time) in languages in which it is heavy relative to languages with light CVC [Gordon (2002)]. This paper compares multiple potential acoustic and perceptual correlates of syllable weight. A representative cross section of syllable types in words uttered by speakers of four languages was recorded. In two languages (Arabic, Hindi), CVC is heavy; in two languages (Mongolian, Malayalam), CVC is light. Three measurements were taken: duration of the syllable rime, acoustic intensity integrated over the rime, and a measure of perceptual energy of the rime incorporating various factors (e.g., temporal integration and adaptation, bandpass filtering). Results thus far indicate that a measure of prominence factoring in both intensity and duration better distinguishes languages on the basis of weight criterion than a simple measure of duration. The perceptual energy measure provides a slightly better fit than acoustic energy. [Work supported by NSF.
Full Text Available A recent study showed that adaptation to causal events (collisions in adults caused subsequent events to be less likely perceived as causal. In this study, we examined if a similar negative adaptation effect for perceptual causality occurs in children, both typically developing and with autism. Previous studies have reported diminished adaptation for face identity, facial configuration and gaze direction in children with autism. To test whether diminished adaptive coding extends beyond high-level social stimuli (such as faces and could be a general property of autistic perception, we developed a child-friendly paradigm for adaptation of perceptual causality. We compared the performance of 22 children with autism with 22 typically developing children, individually matched on age and ability (IQ scores. We found significant and equally robust adaptation aftereffects for perceptual causality in both groups. There were also no differences between the two groups in their attention, as revealed by reaction times and accuracy in a change-detection task. These findings suggest that adaptation to perceptual causality in autism is largely similar to typical development and, further, that diminished adaptive coding might not be a general characteristic of autism at low levels of the perceptual hierarchy, constraining existing theories of adaptation in autism.
Karaminis, Themelis; Turi, Marco; Neil, Louise; Badcock, Nicholas A; Burr, David; Pellicano, Elizabeth
A recent study showed that adaptation to causal events (collisions) in adults caused subsequent events to be less likely perceived as causal. In this study, we examined if a similar negative adaptation effect for perceptual causality occurs in children, both typically developing and with autism. Previous studies have reported diminished adaptation for face identity, facial configuration and gaze direction in children with autism. To test whether diminished adaptive coding extends beyond high-level social stimuli (such as faces) and could be a general property of autistic perception, we developed a child-friendly paradigm for adaptation of perceptual causality. We compared the performance of 22 children with autism with 22 typically developing children, individually matched on age and ability (IQ scores). We found significant and equally robust adaptation aftereffects for perceptual causality in both groups. There were also no differences between the two groups in their attention, as revealed by reaction times and accuracy in a change-detection task. These findings suggest that adaptation to perceptual causality in autism is largely similar to typical development and, further, that diminished adaptive coding might not be a general characteristic of autism at low levels of the perceptual hierarchy, constraining existing theories of adaptation in autism.
Karaminis, Themelis; Turi, Marco; Neil, Louise; Badcock, Nicholas A.; Burr, David; Pellicano, Elizabeth
A recent study showed that adaptation to causal events (collisions) in adults caused subsequent events to be less likely perceived as causal. In this study, we examined if a similar negative adaptation effect for perceptual causality occurs in children, both typically developing and with autism. Previous studies have reported diminished adaptation for face identity, facial configuration and gaze direction in children with autism. To test whether diminished adaptive coding extends beyond high-level social stimuli (such as faces) and could be a general property of autistic perception, we developed a child-friendly paradigm for adaptation of perceptual causality. We compared the performance of 22 children with autism with 22 typically developing children, individually matched on age and ability (IQ scores). We found significant and equally robust adaptation aftereffects for perceptual causality in both groups. There were also no differences between the two groups in their attention, as revealed by reaction times and accuracy in a change-detection task. These findings suggest that adaptation to perceptual causality in autism is largely similar to typical development and, further, that diminished adaptive coding might not be a general characteristic of autism at low levels of the perceptual hierarchy, constraining existing theories of adaptation in autism. PMID:25774507
Dastageeri, H.; Storz, M.; Koukofikis, A.; Knauth, S.; Coors, V.
Providing mobile location-based information for pedestrians faces many challenges. On one hand the accuracy of localisation indoors and outdoors is restricted due to technical limitations of GPS and Beacons. Then again only a small display is available to display information as well as to develop a user interface. Plus, the software solution has to consider the hardware characteristics of mobile devices during the implementation process for aiming a performance with minimum latency. This paper describes our approach by including a combination of image tracking and GPS or Beacons to ensure orientation and precision of localisation. To communicate the information on Points of Interest (POIs), we decided to choose Augmented Reality (AR). For this concept of operations, we used besides the display also the acceleration and positions sensors as a user interface. This paper especially goes into detail on the optimization of the image tracking algorithms, the development of the video-based AR player for the Android platform and the evaluation of videos as an AR element in consideration of providing a good user experience. For setting up content for the POIs or even generate a tour we used and extended the Open Geospatial Consortium (OGC) standard Augmented Reality Markup Language (ARML).
Gomella, L G; Albertsen, P C; Benson, M C; Forman, J D; Soloway, M S
Increased consumerism, patient empowerment, and autonomy are creating a health care revolution. In recent years, the public has become better informed and more sophisticated. An extraordinary amount of treatment advice from books, the media, and the Internet is available to patients today, although much of it is confusing or conflicting. Consequently, the traditional, paternalistic doctor-patient relationship is yielding to a more consumerist one. The new dynamic is based on a participatory ethic and a change in the balance of power. This shared decision-making creates a true partnership between professionals and patients, in which each contributes equally to decisions about treatment or care. Evidence suggests that in diseases such as prostate cancer, where there may be a number of appropriate treatment options for a particular patient, shared decision-making may lead to improved clinical and quality-of-life outcomes. This article explores the evolving relationship between the physician and patient, the pros and cons of shared decision-making, and the use of video technology in the clinical setting. The authors review the use of medical decision aids, including a video-based educational program called CHOICES, in the treatment of prostate cancer and other diseases.
Full Text Available Currently, many placement-based health programme students within the UK are supported through face-to-face visits from university staff. Whilst cited in literature as being of value, the face-to-face nature of this contact is not supported. Alternatives including video-based communications methods offer the potential for cost effective, environmentally responsible support. However, in order to establish the fitness for purpose of alternative approaches, the content and purpose of current support needs to be understood. This project aimed to investigate student perceptions of the ideal content and purpose of clinical support visits, and alternatives to the current face-to-face approach. Fifty-six Physiotherapy undergraduate students responded to questionnaires with a further nine participating in a follow-up focus group. Participants emphasised the value of the visit in guiding learning, ensuring progression and resolving arising issues, and highlighted concerns over alternative approaches. Focus group participants discussed the importance of personal and professional confidence in directing requirements for support, and went on to propose a menu of options for methods of communication. Whilst limited in some applications, video technologies may be one of the options. Overall, however, this project supports the need for consideration of individualised learning journeys within curriculum planning.
Full Text Available Technological progress in the fields of Micro Electro-Mechanical Systems (MEMS and wireless communications and also the availability of CMOS cameras, microphones and small-scale array sensors, which may ubiquitously capture multimedia content from the field, have fostered the development of low-cost limited resources Wireless Video-based Sensor Networks (WVSN. With regards to the constraints of videobased sensor nodes and wireless sensor networks, a supporting video stream is not easy to implement with the present sensor network protocols. In this paper, a thorough architecture is presented for video transmission over WVSN called Energy-efficient and high-Quality Video transmission Architecture (EQV-Architecture. This architecture influences three layers of communication protocol stack and considers wireless video sensor nodes constraints like limited process and energy resources while video quality is preserved in the receiver side. Application, transport, and network layers are the layers in which the compression protocol, transport protocol, and routing protocol are proposed respectively, also a dropping scheme is presented in network layer. Simulation results over various environments with dissimilar conditions revealed the effectiveness of the architecture in improving the lifetime of the network as well as preserving the video quality.
Aghdasi, Hadi S; Abbaspour, Maghsoud; Moghadam, Mohsen Ebrahimi; Samei, Yasaman
Technological progress in the fields of Micro Electro-Mechanical Systems (MEMS) and wireless communications and also the availability of CMOS cameras, microphones and small-scale array sensors, which may ubiquitously capture multimedia content from the field, have fostered the development of low-cost limited resources Wireless Video-based Sensor Networks (WVSN). With regards to the constraints of videobased sensor nodes and wireless sensor networks, a supporting video stream is not easy to implement with the present sensor network protocols. In this paper, a thorough architecture is presented for video transmission over WVSN called Energy-efficient and high-Quality Video transmission Architecture (EQV-Architecture). This architecture influences three layers of communication protocol stack and considers wireless video sensor nodes constraints like limited process and energy resources while video quality is preserved in the receiver side. Application, transport, and network layers are the layers in which the compression protocol, transport protocol, and routing protocol are proposed respectively, also a dropping scheme is presented in network layer. Simulation results over various environments with dissimilar conditions revealed the effectiveness of the architecture in improving the lifetime of the network as well as preserving the video quality.
Armstrong, April W; Idriss, Nayla Z; Kim, Randie H
To compare online video and pamphlet education at improving patient comprehension and adherence to sunscreen use, and to assess patient satisfaction with the two educational approaches. In a randomized controlled trial, 94 participants received either online, video-based education or pamphlet-based education that described the importance and proper use of sunscreen. Sun protective knowledge and sunscreen application behaviors were assessed at baseline and 12 weeks after group-specific intervention. Participants in both groups had similar levels of baseline sunscreen knowledge. Post-study analysis revealed significantly greater improvement in the knowledge scores from video group members compared to the pamphlet group (p=0.003). More importantly, video group participants reported greater sunscreen adherence (peducation vehicle more useful and appealing than the pamphlet group (peducational tool for teaching sun protective knowledge and encouraging sunscreen use than written materials. More effective patient educational methods to encourage sun protection activities, such as regular sunscreen use, have the potential to increase awareness and foster positive, preventative health behaviors against skin cancers. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.
Full Text Available Providing mobile location-based information for pedestrians faces many challenges. On one hand the accuracy of localisation indoors and outdoors is restricted due to technical limitations of GPS and Beacons. Then again only a small display is available to display information as well as to develop a user interface. Plus, the software solution has to consider the hardware characteristics of mobile devices during the implementation process for aiming a performance with minimum latency. This paper describes our approach by including a combination of image tracking and GPS or Beacons to ensure orientation and precision of localisation. To communicate the information on Points of Interest (POIs, we decided to choose Augmented Reality (AR. For this concept of operations, we used besides the display also the acceleration and positions sensors as a user interface. This paper especially goes into detail on the optimization of the image tracking algorithms, the development of the video-based AR player for the Android platform and the evaluation of videos as an AR element in consideration of providing a good user experience. For setting up content for the POIs or even generate a tour we used and extended the Open Geospatial Consortium (OGC standard Augmented Reality Markup Language (ARML.
Full Text Available Introduction: Speech recognition in adverse listening conditions becomes more difficult as we age, particularly for individuals with age-related hearing loss (ARHL. Whether these difficulties can be eased with training remains debated, because it is not clear whether the outcomes are sufficiently general to be of use outside of the training context. The aim of the current study was to compare training-induced learning and generalization between normal-hearing older adults and those with ARHL.Methods: 56 listeners (60-72 y/o, 35 participants with ARHL and 21 normal hearing adults participated in the study. The study design was a cross over design with three groups (immediate-training, delayed-training and no-training group. Trained participants received 13 sessions of home-based auditory training over the course of 4 weeks. Three adverse listening conditions were targeted: (1 Speech-in-noise (2 time compressed speech and (3 competing speakers, and the outcomes of training were compared between normal and ARHL groups. Pre- and post-test sessions were completed by all participants. Outcome measures included tests on all of the trained conditions as well as on a series of untrained conditions designed to assess the transfer of learning to other speech and non-speech conditions. Results: Significant improvements on all trained conditions were observed in both ARHL and normal-hearing groups over the course of training. Normal hearing participants learned more than participants with ARHL in the speech-in-noise condition, but showed similar patterns of learning in the other conditions. Greater pre- to post-test changes were observed in trained than in untrained listeners on all trained conditions. In addition, the ability of trained listeners from the ARHL group to discriminate minimally different pseudowords in noise also improved with training. Conclusions: ARHL did not preclude auditory perceptual learning but there was little generalization to
Kennedy, A M; Boyle, E M; Traynor, O; Walsh, T; Hill, A D K
There is considerable interest in the identification and assessment of underlying aptitudes or innate abilities that could potentially predict excellence in the technical aspects of operating. However, before the assessment of innate abilities is introduced for high-stakes assessment (such as competitive selection into surgical training programs), it is essential to determine that these abilities are stable and unchanging and are not influenced by other factors, such as the use of video games. The aim of this study was to investigate whether experience playing video games will predict psychomotor performance on a laparoscopic simulator or scores on tests of visuospatial and perceptual abilities, and to examine the correlation, if any, between these innate abilities. Institutional ethical approval was obtained. Thirty-eight undergraduate medical students with no previous surgical experience were recruited. All participants completed a self-reported questionnaire that asked them to detail their video game experience. They then underwent assessment of their psychomotor, visuospatial, and perceptual abilities using previously validated tests. The results were analyzed using independent samples t tests to compare means and linear regression curves for subsequent analysis. Students who played video games for at least 7 hours per week demonstrated significantly better psychomotor skills than students who did not play video games regularly. However, there was no difference on measures of visuospatial and perceptual abilities. There was no correlation between psychomotor tests and visuospatial or perceptual tests. Regular video gaming correlates positively with psychomotor ability, but it does not seem to influence visuospatial or perceptual ability. This study suggests that video game experience might be beneficial to a future career in surgery. It also suggests that relevant surgical skills may be gained usefully outside the operating room in activities that are not
Swan, Kristen; Myers, Emily
Adults tend to perceive speech sounds from their native language as members of distinct and stable categories; however, they fail to perceive differences between many non-native speech sounds without a great deal of training. The present study investigates the effects of categorization training on adults' ability to discriminate non-native phonetic contrasts. It was hypothesized that only individuals who successfully learned the appropriate categories would show selective improvements in discriminating between-category contrasts. Participants were trained to categorize progressively narrow phonetic contrasts across one of two non-native boundaries, with discrimination pre- and post-tests completed to measure the effects of training on participants' perceptual sensitivity. Results suggest that changes in adults' ability to discriminate a non-native contrast depend on their successful learning of the relevant category structure. Furthermore, post-training identification functions show that changes in perceptual categories specifically correspond to their relative placement of the category boundary. Taken together, these results indicate that learning to assign category labels to a non-native speech continuum is sufficient to induce discontinuous perception of between- versus within-category contrasts.
Full Text Available Visual perceptual learning (VPL can improve spatial vision in normally sighted and visually impaired individuals. Although previous studies of humans and large animals have explored the neural basis of VPL, elucidation of the underlying cellular and molecular mechanisms remains a challenge. Owing to the advantages of molecular genetic and optogenetic manipulations, the mouse is a promising model for providing a mechanistic understanding of VPL. Here, we thoroughly evaluated the effects and properties of VPL on spatial vision in C57BL/6J mice using a two-alternative, forced-choice visual water task. Briefly, the mice underwent prolonged training at near the individual threshold of contrast or spatial frequency (SF for pattern discrimination or visual detection for 35 consecutive days. Following training, the contrast-threshold trained mice showed an 87% improvement in contrast sensitivity (CS and a 55% gain in visual acuity (VA. Similarly, the SF-threshold trained mice exhibited comparable and long-lasting improvements in VA and significant gains in CS over a wide range of SFs. Furthermore, learning largely transferred across eyes and stimulus orientations. Interestingly, learning could transfer from a pattern discrimination task to a visual detection task, but not vice versa. We validated that this VPL fully restored VA in adult amblyopic mice and old mice. Taken together, these data indicate that mice, as a species, exhibit reliable VPL. Intrinsic signal optical imaging revealed that mice with perceptual training had higher cut-off SFs in primary visual cortex (V1 than those without perceptual training. Moreover, perceptual training induced an increase in the dendritic spine density in layer 2/3 pyramidal neurons of V1. These results indicated functional and structural alterations in V1 during VPL. Overall, our VPL mouse model will provide a platform for investigating the neurobiological basis of VPL.
Fabian A. Soto
Full Text Available Determining whether perceptual properties are processed independently is an important goal in perceptual science, and tools to test independence should be widely available to experimental researchers. The best analytical tools to test for perceptual independence are provided by General Recognition Theory (GRT, a multidimensional extension of signal detection theory. Unfortunately, there is currently a lack of software implementing GRT analyses that is ready-to-use by experimental psychologists and neuroscientists with little training in computational modeling. This paper presents grtools, an R package developed with the explicit aim of providing experimentalists with the ability to perform full GRT analyses using only a couple of command lines. We describe the software and provide a practical tutorial on how to perform each of the analyses available in grtools. We also provide advice to researchers on best practices for experimental design and interpretation of results when applying GRT and grtools
Full Text Available Previous research suggests that high functioning children with Autism Spectrum Disorder (ASD sometimes have problems learning categories, but often appear to perform normally in categorization tasks. The deficits that individuals with ASD show when learning categories have been attributed to executive dysfunction, general deficits in implicit learning, atypical cognitive strategies, or abnormal perceptual biases and abilities. Several of these psychological explanations for category learning deficits have been associated with neural abnormalities such as cortical underconnectivity. The present study evaluated how well existing neurally-based theories account for atypical perceptual category learning shown by high functioning children with ASD across multiple category learning tasks involving novel, abstract shapes. Consistent with earlier results, children’s performances revealed two distinct patterns of learning and generalization associated with ASD: one was indistinguishable from performance in typically developing children; the other revealed dramatic impairments. These two patterns were evident regardless of training regimen or stimulus set. Surprisingly, some children with ASD showed both patterns. Simulations of perceptual category learning could account for the two observed patterns in terms of differences in neural plasticity. However, no current psychological or neural theory adequately explains why a child with ASD might show such large fluctuations in category learning ability across training conditions or stimulus sets.
Mano, Hiroaki; Yoshida, Wako; Shibata, Kazuhisa; Zhang, Suyi; Koltzenburg, Martin; Kawato, Mitsuo; Seymour, Ben
The location of a sensory cortex for temperature perception remains a topic of substantial debate. Both the parietal-opercular (SII) and posterior insula have been consistently implicated in thermosensory processing, but neither region has yet been identified as the locus of fine temperature discrimination. Using a perceptual learning paradigm in male and female humans, we show improvement in discrimination accuracy for subdegree changes in both warmth and cool detection over 5 d of repetitive training. We found that increases in discriminative accuracy were specific to the temperature (cold or warm) being trained. Using structural imaging to look for plastic changes associated with perceptual learning, we identified symmetrical increases in gray matter volume in the SII cortex. Furthermore, we observed distinct, adjacent regions for cold and warm discrimination, with cold discrimination having a more anterior locus than warm. The results suggest that thermosensory discrimination is supported by functionally and anatomically distinct temperature-specific modules in the SII cortex.SIGNIFICANCE STATEMENT We provide behavioral and neuroanatomical evidence that perceptual learning is possible within the temperature system. We show that structural plasticity localizes to parietal-opercular (SII), and not posterior insula, providing the best evidence to date resolving a longstanding debate about the location of putative "temperature cortex." Furthermore, we show that cold and warm pathways are behaviorally and anatomically dissociable, suggesting that the temperature system has distinct temperature-dependent processing modules. Copyright © 2017 Mano et al.
Lu, Zhong-Lin; Chu, Wilson; Dosher, Barbara Anne; Lee, Sophia
We combined the external noise paradigm, the Perceptual Template Model approach, and transfer tests to investigate the mechanisms and eye-specificity of perceptual learning of Gabor orientation in visual periphery. Coupled with a fixation task, discriminating a 5 from an S in a rapid small character string at fixation, contrast thresholds were estimated for each of eight external noise levels at two performance criteria using 3/1 and 2/1 staircases. Perceptual learning in one eye was measured over 10 practice sessions, followed by five sessions of practice in the new eye to assess transfer. We found that monocular learning improved performance (reduced contrast thresholds) with virtually equal magnitude across a wide range of external noise levels with no significant change in central task performance. Based on measurements of learning effects at two performance criterion levels, we identified a mixture of stimulus enhancement and external noise exclusion as the mechanism of perceptual learning underlying the observed improvements. Perceptual learning in the trained eye generalized completely to the untrained eye. We related the transfer patterns to known physiology and psychophysics on orientation direction coding.
Wilms, Inge Linda; Nielsen, Simon
Visual perception serves as the basis for much of the higher level cognitive processing as well as human activity in general. Here we present normative estimates for the following components of visual perception: the visual perceptual threshold, the visual short-term memory capacity and the visual...... perceptual encoding/decoding speed (processing speed) of visual short-term memory based on an assessment of 91 healthy subjects aged 60-75. The estimates are presented at total sample level as well as at gender level. The estimates were modelled from input from a whole-report assessment based on A Theory...... speed of Visual Short-term Memory (VTSM) but not the capacity of VSTM nor the visual threshold. The estimates will be useful for future studies into the effects of various types of intervention and training on cognition in general and visual attention in particular....
Roseli Saraiva Moreira Bittar; Eliane Maria Dias von Söhsten Lins
INTRODUCTION: Persistent postural-perceptual dizziness is the dizziness that lasts for over three months with no clinical explanation for its persistence. The patient's motor response pattern presents changes and most patients manifest significant anxiety. OBJECTIVE: To evaluate the clinical characteristics of patients with persistent postural and perceptual dizziness. METHODS: statistical analysis of clinical aspects of patients with persistent postural-perceptual dizziness. RESULTS: 81 pati...
Full Text Available The present paper provides a short critical review of the theory of perceptual load. It closely examines the basic tenets and assumptions of the theory and identifies major conceptual and methodological problems that have been largely ignored in the literature. The discussion focuses on problems in the definition of the concept of perceptual load, on the circularity in the characterization and manipulation of perceptual load and the confusion between the concept of perceptual load and its operationalization. The paper also selectively reviews evidence supporting the theory as well as inconsistent evidence which proposed alternative dominant factors influencing the efficacy of attentional selection.
Guerra, Ricardo Oliveira; Oliveira, Bruna Silva; Alvarado, Beatriz Eugenia; Curcio, Carmen Lucia; Rejeski, W Jack; Marsh, Anthony P; Ip, Edward H; Barnard, Ryan T; Guralnik, Jack M; Zunzunegui, Maria Victoria
To assess the reliability and the validity of Portuguese- and Spanish-translated versions of the video-based short-form Mobility Assessment Tool in assessing self-reported mobility, and to provide evidence for the applicability of these videos in elderly Latin American populations as a complement to physical performance measures. The sample consisted of 300 elderly participants (150 from Brazil, 150 from Colombia) recruited at neighborhood social centers. Mobility was assessed with the Mobility Assessment Tool, and compared with the Short Physical Performance Battery score and self-reported functional limitations. Reliability was calculated using intraclass correlation coefficients. Multiple linear regression analyses were used to assess associations among mobility assessment tools and health, and sociodemographic variables. A significant gradient of increasing Mobility Assessment Tool score with better physical function was observed for both self-reported and objective measures, and in each city. Associations between self-reported mobility and health were strong, and significant. Mobility Assessment Tool scores were lower in women at both sites. Intraclass correlation coefficients of the Mobility Assessment Tool were 0.94 (95% confidence interval 0.90-0.97) in Brazil and 0.81 (95% confidence interval 0.66-0.91) in Colombia. Mobility Assessment Tool scores were lower in Manizales than in Natal after adjustment by Short Physical Performance Battery, self-rated health and sex. These results provide evidence for high reliability and good validity of the Mobility Assessment Tool in its Spanish and Portuguese versions used in Latin American populations. In addition, the Mobility Assessment Tool can detect mobility differences related to environmental features that cannot be captured by objective performance measures. © 2013 Japan Geriatrics Society.
Full Text Available Recognizing others’ emotional states is crucial for effective social interaction. While most facial emotion recognition tasks use explicit prompts that trigger consciously controlled processing, emotional faces are almost exclusively processed implicitly in real life. Recent attempts in social cognition suggest a dual process perspective, whereby explicit and implicit processes largely operate independently. However, due to differences in methodology the direct comparison of implicit and explicit social cognition has remained a challenge.Here, we introduce a new tool to comparably measure implicit and explicit processing aspects comprising basic and complex emotions in facial expressions. We developed two video-based tasks with similar answer formats to assess performance in respective facial emotion recognition processes: Face Puzzle, implicit and explicit. To assess the tasks’ sensitivity to atypical social cognition and to infer interrelationship patterns between explicit and implicit processes in typical and atypical development, we included healthy adults (NT, n= 24 and adults with autism spectrum disorder (ASD, n = 24.Item analyses yielded good reliability of the new tasks. Group-specific results indicated sensitivity to subtle social impairments in high-functioning ASD. Correlation analyses with established implicit and explicit socio-cognitive measures were further in favor of the tasks’ external validity. Between group comparisons provide first hints of differential relations between implicit and explicit aspects of facial emotion recognition processes in healthy compared to ASD participants. In addition, an increased magnitude of between group differences in the implicit task was found for a speed-accuracy composite measure. The new Face Puzzle tool thus provides two new tasks to separately assess explicit and implicit social functioning, for instance, to measure subtle impairments as well as potential improvements due to social
Waldron, Nicholas; Johnson, Claire E; Saul, Peter; Waldron, Heidi; Chong, Jeffrey C; Hill, Anne-Marie; Hayes, Barbara
Advance cardiopulmonary resuscitation (CPR) decision-making and escalation of care discussions are variable in routine clinical practice. We aimed to explore physician barriers to advance CPR decision-making in an inpatient hospital setting and develop a pragmatic intervention to support clinicians to undertake and document routine advance care planning discussions. Two focus groups, which involved eight consultants and ten junior doctors, were conducted following a review of the current literature. A subsequent iterative consensus process developed two intervention elements: (i) an updated 'Goals of Patient Care' (GOPC) form and process; (ii) an education video and resources for teaching advance CPR decision-making and communication. A multidisciplinary group of health professionals and policy-makers with experience in systems development, education and research provided critical feedback. Three key themes emerged from the focus groups and the literature, which identified a structure for the intervention: (i) knowing what to say; (ii) knowing how to say it; (iii) wanting to say it. The themes informed the development of a video to provide education about advance CPR decision-making framework, improving communication and contextualising relevant clinical issues. Critical feedback assisted in refining the video and further guided development and evolution of a medical GOPC approach to discussing and recording medical treatment and advance care plans. Through an iterative process of consultation and review, video-based education and an expanded GOPC form and approach were developed to address physician and systemic barriers to advance CPR decision-making and documentation. Implementation and evaluation across hospital settings is required to examine utility and determine effect on quality of care.
Qi, Yonggang; Guo, Jun; Li, Yi
Gestalt principles, a set of conjoining rules derived from hu- man visual studies, have been known to play an important role in computer vision. Many applications such as image segmentation, contour grouping and scene understanding of- ten rely on such rules to work. However, the problem of Gestalt...... the importance of Gestalt rules by solving a learning to rank problem, and formulate a multi-label graph-cuts algo- rithm to group image primitives while taking into account the learned Gestalt confliction. Our experiment results confirm the existence of Gestalt confliction in perceptual grouping and demonstrate...
Watson, Andrew B.
A perceptual-components architecture for digital video partitions the image stream into signal components in a manner analogous to that used in the human visual system. These components consist of achromatic and opponent color channels, divided into static and motion channels, further divided into bands of particular spatial frequency and orientation. Bits are allocated to an individual band in accord with visual sensitivity to that band and in accord with the properties of visual masking. This architecture is argued to have desirable features such as efficiency, error tolerance, scalability, device independence, and extensibility.
Volk, Christer Peter; Pedersen, Torben Holm; Bech, Søren
This study tested a framework for modelling of sensory descriptors (words) differentiating headphones. Six descriptors were included in a listening test with recordings of the sound reproductions of seven prototype headphones. A comprehensive data quality analysis investigated both the performance...... of the listeners and the suitability of the descriptors for modelling. Additionally, two strategies were utilised for modelling metrics describing these descriptors, both relying on specific loudness stimations of the listening test stimuli. The stability of the initially found metrics was tested to quantify...... the potential of the metrics for future predictions within the perceptual space spanned by the headphones....
Heald, Shannon L. M.; Van Hedger, Stephen C.; Nusbaum, Howard C.
In our auditory environment, we rarely experience the exact acoustic waveform twice. This is especially true for communicative signals that have meaning for listeners. In speech and music, the acoustic signal changes as a function of the talker (or instrument), speaking (or playing) rate, and room acoustics, to name a few factors. Yet, despite this acoustic variability, we are able to recognize a sentence or melody as the same across various kinds of acoustic inputs and determine meaning based on listening goals, expectations, context, and experience. The recognition process relates acoustic signals to prior experience despite variability in signal-relevant and signal-irrelevant acoustic properties, some of which could be considered as “noise” in service of a recognition goal. However, some acoustic variability, if systematic, is lawful and can be exploited by listeners to aid in recognition. Perceivable changes in systematic variability can herald a need for listeners to reorganize perception and reorient their attention to more immediately signal-relevant cues. This view is not incorporated currently in many extant theories of auditory perception, which traditionally reduce psychological or neural representations of perceptual objects and the processes that act on them to static entities. While this reduction is likely done for the sake of empirical tractability, such a reduction may seriously distort the perceptual process to be modeled. We argue that perceptual representations, as well as the processes underlying perception, are dynamically determined by an interaction between the uncertainty of the auditory signal and constraints of context. This suggests that the process of auditory recognition is highly context-dependent in that the identity of a given auditory object may be intrinsically tied to its preceding context. To argue for the flexible neural and psychological updating of sound-to-meaning mappings across speech and music, we draw upon examples
Shannon L. M. Heald
Full Text Available In our auditory environment, we rarely experience the exact acoustic waveform twice. This is especially true for communicative signals that have meaning for listeners. In speech and music, the acoustic signal changes as a function of the talker (or instrument, speaking (or playing rate, and room acoustics, to name a few factors. Yet, despite this acoustic variability, we are able to recognize a sentence or melody as the same across various kinds of acoustic inputs and determine meaning based on listening goals, expectations, context, and experience. The recognition process relates acoustic signals to prior experience despite variability in signal-relevant and signal-irrelevant acoustic properties, some of which could be considered as “noise” in service of a recognition goal. However, some acoustic variability, if systematic, is lawful and can be exploited by listeners to aid in recognition. Perceivable changes in systematic variability can herald a need for listeners to reorganize perception and reorient their attention to more immediately signal-relevant cues. This view is not incorporated currently in many extant theories of auditory perception, which traditionally reduce psychological or neural representations of perceptual objects and the processes that act on them to static entities. While this reduction is likely done for the sake of empirical tractability, such a reduction may seriously distort the perceptual process to be modeled. We argue that perceptual representations, as well as the processes underlying perception, are dynamically determined by an interaction between the uncertainty of the auditory signal and constraints of context. This suggests that the process of auditory recognition is highly context-dependent in that the identity of a given auditory object may be intrinsically tied to its preceding context. To argue for the flexible neural and psychological updating of sound-to-meaning mappings across speech and music, we
Jonathan R Folstein
Full Text Available Category learning facilitates perception along relevant stimulus dimensions, even when tested in a discrimination task that does not require categorization. While this general phenomenon has been demonstrated previously, perceptual facilitation along dimensions has been documented by measuring different specific phenomena in different studies using different kinds of objects. Across several object domains, there is support for acquired distinctiveness, the stretching of a perceptual dimension relevant to learned categories. Studies using faces and studies using simple separable visual dimensions have also found evidence of acquired equivalence, the shrinking of a perceptual dimension irrelevant to learned categories, and categorical perception, the local stretching across the category boundary. These later two effects are rarely observed with complex non-face objects. Failures to find these effects with complex non-face objects may have been because the dimensions tested previously were perceptually integrated. Here we tested effects of category learning with non-face objects categorized along dimensions that have been found to be processed by different areas of the brain, shape and motion. While we replicated acquired distinctiveness, we found no evidence for acquired equivalence or categorical perception.
Besken, Miri; Mulligan, Neil W.
Judgments of learning (JOLs) are sometimes influenced by factors that do not impact actual memory performance. One recent proposal is that perceptual fluency during encoding affects metamemory and is a basis of metacognitive illusions. In the present experiments, participants identified aurally presented words that contained inter-spliced silences…
Larcombe, Stephanie J; Kennard, Chris; Bridge, Holly
Repeated practice of a specific task can improve visual performance, but the neural mechanisms underlying this improvement in performance are not yet well understood. Here we trained healthy participants on a visual motion task daily for 5 days in one visual hemifield. Before and after training, we used functional magnetic resonance imaging (fMRI) to measure the change in neural activity. We also imaged a control group of participants on two occasions who did not receive any task training. While in the MRI scanner, all participants completed the motion task in the trained and untrained visual hemifields separately. Following training, participants improved their ability to discriminate motion direction in the trained hemifield and, to a lesser extent, in the untrained hemifield. The amount of task learning correlated positively with the change in activity in the medial superior temporal (MST) area. MST is the anterior portion of the human motion complex (hMT+). MST changes were localized to the hemisphere contralateral to the region of the visual field, where perceptual training was delivered. Visual areas V2 and V3a showed an increase in activity between the first and second scan in the training group, but this was not correlated with performance. The contralateral anterior hippocampus and bilateral dorsolateral prefrontal cortex (DLPFC) and frontal pole showed changes in neural activity that also correlated with the amount of task learning. These findings emphasize the importance of MST in perceptual learning of a visual motion task. Hum Brain Mapp 39:145-156, 2018. © 2017 Wiley Periodicals, Inc. © 2017 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.
Full Text Available The auditory system of adult listeners has been shown to accommodate to altered spectral cues to sound location which presumably provides the basis for recalibration to changes in the shape of the ear over a life time. Here we review the role of auditory and non-auditory inputs to the perception of sound location and consider a range of recent experiments looking at the role of non-auditory inputs in the process of accommodation to these altered spectral cues. A number of studies have used small ear moulds to modify the spectral cues that result in significant degradation in localization performance. Following chronic exposure (10-60 days performance recovers to some extent and recent work has demonstrated that this occurs for both audio-visual and audio-only regions of space. This begs the questions as to the teacher signal for this remarkable functional plasticity in the adult nervous system. Following a brief review of influence of the motor state in auditory localisation, we consider the potential role of auditory-motor learning in the perceptual recalibration of the spectral cues. Several recent studies have considered how multi-modal and sensory-motor feedback might influence accommodation to altered spectral cues produced by ear moulds or through virtual auditory space stimulation using non-individualised spectral cues. The work with ear moulds demonstrates that a relatively short period of training involving sensory-motor feedback (5 – 10 days significantly improved both the rate and extent of accommodation to altered spectral cues. This has significant implications not only for the mechanisms by which this complex sensory information is encoded to provide a spatial code but also for adaptive training to altered auditory inputs. The review concludes by considering the implications for rehabilitative training with hearing aids and cochlear prosthesis.
Jones, Tudor Griffith, III
The purpose of this study was to determine the effect of video-based science instruction and accompanying activity-based instruction on the knowledge, attitudes, and behavioral intentions of high school students' use of seat belts. Secondarily, the purpose was to determine order effects and interactions between the two treatments used in the study: video-based instruction and hands-on activity-based instruction. The study used Ajzen and Fishbein's theory of reasoned action to investigate the factors influencing high school students' behavioral intentions regarding seat belt use. This study used a pretest-posttest-posttest treatment design. Data were collected on 194 students in high school introductory biology and chemistry classes in Gainesville, Florida. Ten intact high school science classes (eight treatment and two control) took pretests and posttests measuring physics knowledge, attitudes, and behavioral intentions toward seat belt use prior to and after participating in the two treatments. The treatment group students participated in at least 500 minutes of instructional time divided among five lessons over 10 instructional days. All participants were pretested on physics knowledge, attitudes, and behavioral intentions toward seat belt use prior to two treatments. Treatment A was defined as participating in one 50-minute video-based instructional lesson. Treatment B was defined as participating in four hands-on science activities regarding crash-related physics concepts. Cronbach's coefficient alpha was used for analysis of the researcher-designed instruments, and ANOVA was used to analyze the data. The results of the analyses (p behavioral intentions regarding seat belts use. The treatment sequence did not result in significantly greater (p behavioral intentions regarding seat belt use. The results of this study indicate that video-based instruction and activity-based instruction can positively change knowledge and behavioral intentions related to seat belt
Full Text Available Some theorists hold that the human perceptual system has a component that receives input only from units lower in the perceptual hierarchy. This thesis, that we shall here refer to as the encapsulation thesis, has been at the center of a continuing debate for the past few decades. Those who deny the encapsulation thesis often rely on the large body of psychological findings that allegedly suggest that perception is influenced by factors such as the beliefs, desires, goals, and the expectations of the perceiver. Proponents of the encapsulation thesis, however, often argue that, when correctly interpreted, these psychological findings are compatible with the thesis. In our view, the debate over the significance and the correct interpretation of these psychological findings has reached an impasse. We hold that this impasse is due to the methodological limitations over psychophysical experiments, and it is very unlikely that such experiments, on their own, could yield results that would settle the debate. After defending this claim, we argue that integrating data from cognitive neuroscience resolves the debate in favor of those who deny the encapsulation thesis.
Moser, Jean-Frederic; Staub, Rene; Tompkin, Wayne R.
The criteria by which optically variable devices are judged are aesthetic, semantic, security, ergonomic, and physical/chemical. This paper addresses ergonomic aspects which relate to the human vision and perceptual-cognitive system. Applying some pertinent rules may help greatly to improve the image visual information for easier, more straight-forward reception of a persistent security message. We consider two important aspects of the human visual system that help to determine the ergonomic response to visual displays created using optical diffraction. The human visual system aspect treats the retinal source of information, which is the retinal signal produced when an image of the external world is projected on the retina. The other aspect is the underlying information-processing mechanism of our brains and its constructive operations, which yields the final perceptual information. In this paper we consider information processing methods hidden in the biology of our cognition system. Findings on the relationship between physiology and psychology, sensory results and the activities of the optic pathway and subjective brightness sensations can be applied directly in designing images. Some effects are demonstrated by video tape.
Iliana M. Vargas
Full Text Available In some circumstances, accurate recognition of repeated images in an explicit memory test is driven by implicit memory. We propose that this “implicit recognition” results from perceptual fluency that influences responding without awareness of memory retrieval. Here we examined whether recognition would vary if images appeared in the same or different visual hemifield during learning and testing. Kaleidoscope images were briefly presented left or right of fixation during divided-attention encoding. Presentation in the same visual hemifield at test produced higher recognition accuracy than presentation in the opposite visual hemifield, but only for guess responses. These correct guesses likely reflect a contribution from implicit recognition, given that when the stimulated visual hemifield was the same at study and test, recognition accuracy was higher for guess responses than for responses with any level of confidence. The dramatic difference in guessing accuracy as a function of lateralized perceptual overlap between study and test suggests that implicit recognition arises from memory storage in visual cortical networks that mediate repetition-induced fluency increments.
Kellnhofer, Petr; Ritschel, Tobias; Myszkowski, Karol; Seidel, Hans-Peter
Predicting human visual perception has several applications such as compression, rendering, editing, and retargeting. Current approaches, however, ignore the fact that the human visual system compensates for geometric transformations, e.g., we see that an image and a rotated copy are identical. Instead, they will report a large, false-positive difference. At the same time, if the transformations become too strong or too spatially incoherent, comparing two images gets increasingly difficult. Between these two extrema, we propose a system to quantify the effect of transformations, not only on the perception of image differences but also on saliency and motion parallax. To this end, we first fit local homographies to a given optical flow field, and then convert this field into a field of elementary transformations, such as translation, rotation, scaling, and perspective. We conduct a perceptual experiment quantifying the increase of difficulty when compensating for elementary transformations. Transformation entropy is proposed as a measure of complexity in a flow field. This representation is then used for applications, such as comparison of nonaligned images, where transformations cause threshold elevation, detection of salient transformations, and a model of perceived motion parallax. Applications of our approach are a perceptual level-of-detail for real-time rendering and viewpoint selection based on perceived motion parallax.
Vargas, Iliana M; Voss, Joel L; Paller, Ken A
In some circumstances, accurate recognition of repeated images in an explicit memory test is driven by implicit memory. We propose that this "implicit recognition" results from perceptual fluency that influences responding without awareness of memory retrieval. Here we examined whether recognition would vary if images appeared in the same or different visual hemifield during learning and testing. Kaleidoscope images were briefly presented left or right of fixation during divided-attention encoding. Presentation in the same visual hemifield at test produced higher recognition accuracy than presentation in the opposite visual hemifield, but only for guess responses. These correct guesses likely reflect a contribution from implicit recognition, given that when the stimulated visual hemifield was the same at study and test, recognition accuracy was higher for guess responses than for responses with any level of confidence. The dramatic difference in guessing accuracy as a function of lateralized perceptual overlap between study and test suggests that implicit recognition arises from memory storage in visual cortical networks that mediate repetition-induced fluency increments.
Full Text Available The perceptual hash algorithm is a technique to authenticate the integrity of images. While a few scholars have worked on mono-spectral image perceptual hashing, there is limited research on multispectral image perceptual hashing. In this paper, we propose a perceptual hash algorithm for the content authentication of a multispectral remote sensing image based on the synthetic characteristics of each band: firstly, the multispectral remote sensing image is preprocessed with band clustering and grid partition; secondly, the edge feature of the band subsets is extracted by band fusion-based edge feature extraction; thirdly, the perceptual feature of the same region of the band subsets is compressed and normalized to generate the perceptual hash value. The authentication procedure is achieved via the normalized Hamming distance between the perceptual hash value of the recomputed perceptual hash value and the original hash value. The experiments indicated that our proposed algorithm is robust compared to content-preserved operations and it efficiently authenticates the integrity of multispectral remote sensing images.
This document describes the methods employed in, the information gathered during, and the current status of this project. The project attempted to (1) identify those perceptual skills that appear to be directly related to the basic classroom tasks of reading and arithmetic at the primary level, (2) identify perceptual skills that relate directly…
Li, Haishan; He, Qingshun
Ambiguity tolerance and perceptual learning styles are the two influential elements showing individual differences in EFL learning. This research is intended to explore the relationship between Chinese EFL learners' ambiguity tolerance and their preferred perceptual learning styles. The findings include (1) the learners are sensitive to English…
Full Text Available There is increasing evidence from response time experiments that language statistics and perceptual simulations both play a role in conceptual processing. In an EEG experiment we compared neural activity in cortical regions commonly associated with linguistic processing and visual perceptual processing to determine to what extent symbolic and embodied accounts of cognition applied. Participants were asked to determine the semantic relationship of word pairs (e.g., sky – ground or to determine their iconic relationship (i.e., if the presentation of the pair matched their expected physical relationship. A linguistic bias was found towards the semantic judgment task and a perceptual bias was found towards the iconicity judgment task. More importantly, conceptual processing involved activation in brain regions associated with both linguistic and perceptual processes. When comparing the relative activation of linguistic cortical regions with perceptual cortical regions, the effect sizes for linguistic cortical regions were larger than those for the perceptual cortical regions early in a trial with the reverse being true later in a trial. These results map upon findings from other experimental literature and provide further evidence that processing of concept words relies both on language statistics and on perceptual simulations, whereby linguistic processes precede perceptual simulation processes.
Forster, Sophie; Lavie, Nilli
Perceptual load is a key determinant of distraction by task-irrelevant stimuli (e.g., Lavie, N. (2005). "Distracted and confused?: Selective attention under load." "Trends in Cognitive Sciences," 9, 75-82). Here we establish the role of perceptual load in determining an internal form of distraction by task-unrelated thoughts (TUTs or…
van Elk, M.
Previous studies have shown that one’s prior beliefs have a strong effect on perceptual decision-making and attentional processing. The present study extends these findings by investigating how individual differences in paranormal and conspiracy beliefs are related to perceptual and attentional
Sheridan, Heather; Reingold, Eyal M.
The present experiments examined perceptual specificity effects using a rereading paradigm. Eye movements were monitored while participants read the same target word twice, in two different low-constraint sentence frames. The congruency of perceptual processing was manipulated by either presenting the target word in the same distortion typography…
Lansford, Kaitlin L; Liss, Julie M; Norton, Rebecca E
In this investigation, the construct of perceptual similarity was explored in the dysarthrias. Specifically, we employed an auditory free-classification task to determine whether listeners could cluster speakers by perceptual similarity, whether the clusters mapped to acoustic metrics, and whether the clusters were constrained by dysarthria subtype diagnosis. Twenty-three listeners blinded to speakers' medical and dysarthria subtype diagnoses participated. The task was to group together (drag and drop) the icons corresponding to 33 speakers with dysarthria on the basis of how similar they sounded. Cluster analysis and multidimensional scaling (MDS) modeled the perceptual dimensions underlying similarity. Acoustic metrics and perceptual judgments were used in correlation analyses to facilitate interpretation of the derived dimensions. Six clusters of similar-sounding speakers and 3 perceptual dimensions underlying similarity were revealed. The clusters of similar-sounding speakers were not constrained by dysarthria subtype diagnosis. The 3 perceptual dimensions revealed by MDS were correlated with metrics for articulation rate, intelligibility, and vocal quality, respectively. This study shows (a) feasibility of a free-classification approach for studying perceptual similarity in dysarthria, (b) correspondence between acoustic and perceptual metrics to clusters of similar-sounding speakers, and (c) similarity judgments transcended dysarthria subtype diagnosis.
Fair, Joseph; Flom, Ross; Jones, Jacob; Martin, Justin
Six-month-olds reliably discriminate different monkey and human faces whereas 9-month-olds only discriminate different human faces. It is often falsely assumed that perceptual narrowing reflects a permanent change in perceptual abilities. In 3 experiments, ninety-six 12-month-olds' discrimination of unfamiliar monkey faces was examined. Following…
McLean, Blake D; Coutts, Aaron J; Kelly, Vince; McGuigan, Michael R; Cormack, Stuart J
The purpose of this study was to examine the changes in neuromuscular, perceptual and hormonal measures following professional rugby league matches during different length between-match microcycles. Twelve professional rugby league players from the same team were assessed for changes in countermovement jump (CMJ) performance (flight time and relative power), perceptual responses (fatigue, well-being and muscle soreness) and salivary hormone (testosterone [T] and cortisol [C]) levels during 5, 7 and 9 d between-match training microcycles. All training was prescribed by the club coaches and was monitored using the session-RPE method. Lower mean daily training load was completed on the 5 d compared with the 7 and 9 d microcycles. CMJ flight time and relative power, perception of fatigue, overall well-being and muscle soreness were significantly reduced in the 48 h following the match in each microcycle (P values following 4 d in each microcycle. Countermovement jump relative power was lower in the 7 d microcycle in comparison with the 9 d microcycle (P rugby league match but can be recovered to baseline levels within 4 d. These findings show that with appropriate training, it is possible to recover neuromuscular and perceptual measures within 4 d after a rugby league match.
Mulvey, M R; Fawkner, H J; Radford, H; Johnson, M I
Integration of prosthetic limb awareness into body schema is likely to aid manual control of the prosthesis. Physiotherapists and prosthetists use techniques to generate mechanical, visual and/or auditory feedback related to stimulation of the stump and proximal residual limb to improve prosthetic limb awareness. Electrical stimulation of afferent nerves using implanted electrodes can generate sensations of touch, joint movement, and position, in the missing, phantom limbs of amputees. We report here a novel hypothesis that non-invasive transcutaneous electrical nerve stimulation (TENS) could be used to facilitate the process of perceptual embodiment of a prosthesis into the body schema of amputees. Using a modified version of the rubber hand illusion (RHI), we have found that TENS paraesthesiae can be made to feel like it is emanating from a prosthetic hand in healthy participants with intact limbs. In addition, participants reported perceptual embodiment of the prosthetic hand into their body schema, i.e. it felt as if it is part of their body. We predict that projecting TENS paraesthesiae into the prosthetic limb(s) of amputees will provide sufficient sensory input to facilitate perceptual embodiment. This could prove to be a simple and inexpensive training aid to improve ambulation and prosthesis success.
Järvinen, Kati; Laukkanen, Anne-Maria; Geneid, Ahmed
Language shift from native (L1) to foreign language (L2) may affect speaker's voice production and induce vocal fatigue. This study investigates the effects of language shift on voice source and perceptual voice quality. This is a comparative experimental study. Twenty-four subjects were recorded in L1 and L2. Twelve of the subjects were native Finnish speakers and 12 were native English speakers, and the foreign languages were English and Finnish. Two groups were created based on reports of fatigability. Group 1 had the subjects who did not report more vocal fatigue in L2 than in L1, and in group 2 those who reported more vocal fatigue in L2 than in L1. Acoustic analyses by inverse filtering were conducted in L1 and L2. Also, the subjects' voices were perceptually evaluated in both languages. Results show that language shift from L1 to L2 increased perceived pressedness of voice. Acoustic analyses correlated with the perceptual evaluations. Also, the subjects who reported more vocal loading had poorer voice quality, more strenuous voice production, more pressed phonation, and a higher pitch. Voice production was less optimal in L2 than in L1. Speech training given in L2 could be beneficial for people who need to use L2 extensively. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.
Repp, B H
The detectability of a deviation from metronomic timing--of a small local increment in interonset interval (IOI) duration--in a musical excerpt is subject to positional biases, or "timing expectations," that are closely related to the expressive timing (sequence of IOI durations) typically produced by musicians in performance (Repp, 1992b, 1998c, 1998d). Experiment 1 replicated this finding with some changes in procedure and showed that the perception-performance correlation is not the result of formal musical training or availability of a musical score. Experiments 2 and 3 used a synchronization task to examine the hypothesis that participants' perceptual timing expectations are due to systematic modulations in the period of a mental timekeeper that also controls perceptual-motor coordination. Indeed, there was systematic variation in the asynchronies between taps and metronomically timed musical event onsets, and this variation was correlated both with the variations in IOI increment detectability (Experiment 1) and with the typical expressive timing pattern in performance. When the music contained local IOI increments (Experiment 2), they were almost perfectly compensated for on the next tap, regardless of their detectability in Experiment 1, which suggests a perceptual-motor feedback mechanism that is sensitive to subthreshold timing deviations. Overall, the results suggest that aspects of perceived musical structure influence the predictions of mental timekeeping mechanisms, thereby creating a subliminal warping of experienced time.
Arazi, Ayelet; Censor, Nitzan; Dinstein, Ilan
Neural activity during repeated presentations of a sensory stimulus exhibits considerable trial-by-trial variability. Previous studies have reported that trial-by-trial neural variability is reduced (quenched) by the presentation of a stimulus. However, the functional significance and behavioral relevance of variability quenching and the potential physiological mechanisms that may drive it have been studied only rarely. Here, we recorded neural activity with EEG as subjects performed a two-interval forced-choice contrast discrimination task. Trial-by-trial neural variability was quenched by ∼40% after the presentation of the stimulus relative to the variability apparent before stimulus presentation, yet there were large differences in the magnitude of variability quenching across subjects. Individual magnitudes of quenching predicted individual discrimination capabilities such that subjects who exhibited larger quenching had smaller contrast discrimination thresholds and steeper psychometric function slopes. Furthermore, the magnitude of variability quenching was strongly correlated with a reduction in broadband EEG power after stimulus presentation. Our results suggest that neural variability quenching is achieved by reducing the amplitude of broadband neural oscillations after sensory input, which yields relatively more reproducible cortical activity across trials and enables superior perceptual abilities in individuals who quench more. Variability quenching is a phenomenon in which neural variability across trials is reduced by the presentation of a stimulus. Although this phenomenon has been reported across a variety of animal and human studies, its functional significance and behavioral relevance have been examined only rarely. Here, we report novel empirical evidence from humans revealing that variability quenching differs dramatically across individual subjects and explains to a certain degree why some individuals exhibit better perceptual abilities than
Chung, Susana T L
Perceptual learning has been shown to be effective in improving visual functions in the normal adult visual system, as well as in adults with amblyopia. In this study, the feasibility of applying perceptual learning to enhance reading speed in people with long-standing central vision loss was evaluated. Six observers (mean age, 73.8) with long-standing central vision loss practiced an oral sentence-reading task, with words presented sequentially using rapid serial visual presentation (RSVP). A pre-test consisted of measurements of visual acuities, RSVP reading speeds for six print sizes, the location of the preferred retinal locus for fixation (fPRL), and fixation stability. Training consisted of six weekly sessions of RSVP reading, with 300 sentences presented per session. A post-test, identical with the pre-test, followed the training. All observers showed improved RSVP reading speed after training. The improvement averaged 53% (range, 34-70%). Comparisons of pre- and post-test measurements revealed little changes in visual acuity, critical print size, location of the fPRL, and fixation stability. The specificity of the learning effect, and the lack of changes to the fPRL location and fixation stability suggest that the improvements are not due to observers adopting a retinal location with better visual capability, or an improvement in fixation. Rather, the improvements are likely to represent genuine plasticity of the visual system despite the older ages of the observers, coupled with long-standing sensory deficits. Perceptual learning might be an effective way of enhancing visual performance for people with central vision loss.
Kühnis, Jürg; Elmer, Stefan; Meyer, Martin; Jäncke, Lutz
A vast amount of previous work has consistently revealed that professional music training is associated with functional and structural alterations of auditory-related brain regions. Meanwhile, there is also an increasing array of evidence, which shows that musicianship facilitates segmental, as well as supra-segmental aspects of speech processing. Based on this evidence, we addressed a novel research question, namely whether professional music training has an influence on the perceptual learning of speech sounds. In the context of an EEG experiment, we presented auditory pseudoword-chimeras, manipulated in terms of spectral- or envelope-related acoustic information, to a group of professional musicians and non-musicians. During EEG measurements, participants were requested to assign the auditory-presented pseudoword-chimeras to one out of four visually presented templates. As expected, both groups showed behavioural learning effects during the time course of the experiment. These learning effects were associated with an increase in accuracy, a decrease in reaction time, as well as a decrease in the P2-like microstate duration in both groups. Notably, the musicians showed an increased learning performance compared to the controls during the first two runs of the spectral condition. This perceptual learning effect, which varies as a function of musical expertise, was reflected by a reduction of the P2-like microstate duration. Results may mirror transfer effects from musical training to the processing of spectral information in speech sounds. Hence, this study provides first evidence for a relationship between changes in microstates, musical expertise, and perceptual verbal learning mechanisms.
Rahnev, Dobromir; Koizumi, Ai; McCurdy, Li Yan; D’Esposito, Mark; Lau, Hakwan
We live in a continuous environment in which the visual scene changes on a slow timescale. It has been shown that, to exploit such environmental stability, the brain creates a “continuity field” such that objects seen seconds ago influence the perception of current objects. What is unknown is whether a similar mechanism exists at the level of our metacognitive representations. In three experiments we demonstrate a robust inter-task “confidence leak” that cannot be explained by response priming or attentional fluctuations. Observers’ ability to modulate this confidence leak predicted higher capacity for metacognition as well as greater gray matter volume in the prefrontal cortex. A model based on normative principles from Bayesian inference explained the results by postulating that observers subjectively estimate the perceptual signal strength in a stable environment. These results point to the existence of a novel metacognitive mechanism mediated by regions in prefrontal cortex. PMID:26408037
Hartmann, Martin; Lartillot, Olivier; Toiviainen, Petri
As music unfolds in time, structure is recognised and understood by listeners, regardless of their level of musical expertise. A number of studies have found spectral and tonal changes to quite successfully model boundaries between structural sections. However, the effects of musical expertise...... and experimental task on computational modelling of structure are not yet well understood. These issues need to be addressed to better understand how listeners perceive the structure of music and to improve automatic segmentation algorithms. In this study, computational prediction of segmentation by listeners...... was investigated for six musical stimuli via a real-time task and an annotation (non real-time) task. The proposed approach involved computation of novelty curve interaction features and a prediction model of perceptual segmentation boundary density. We found that, compared to non-musicians’, musicians...
Kleiner, Mendel; Larsson, Pontus; Vastfjall, Daniel; Torres, Rendell R.
By using various types of binaural simulation (or ``auralization'') of physical environments, it is now possible to study basic perceptual issues relevant to room acoustics, as well to simulate the acoustic conditions found in concert halls and other auditoria. Binaural simulation of physical spaces in general is also important to virtual reality systems. This presentation will begin with an overview of the issues encountered in the auralization of room and other environments. We will then discuss the influence of various approximations in room modeling, in particular, edge- and surface scattering, on the perceived room response. Finally, we will discuss cross-modal effects, such as the influence of visual cues on the perception of auditory cues, and the influence of cross-modal effects on the judgement of ``perceived presence'' and the rating of room acoustic quality.
O'Donovan, Jonathan J; Furlong, Dermot J
This paper describes the design of a bilinear time-frequency distribution which is a joint model of temporal and spectral masking. The distribution is used to generate temporally evolving excitation patterns of nonstationary signals and systems and is conceived as a tool for acousticians and engineers for perceptual time-frequency analysis. Distribution time and frequency resolutions are controlled by a separable kernel consisting of a set of low-pass time and frequency smoothing windows. These windows are designed by adapting existing psychoacoustic models of auditory resolution, rather than using mathematical window functions. Cross-term interference and windowing clutter are highly suppressed for the distribution, ensuring resolution accuracy over a dynamic range sufficient to encompass that of the auditory system (in excess of 100 dB). Application to the analysis of a synthetic and two real signals are included to demonstrate the approach.
Riaan M. Olivier
Full Text Available Background: Thought disorder and visual-perceptual deficits have been well documented, but their relationships with clinical symptoms and cognitive function remain unclear. Cognitive-perceptual deficits may underscore clinical symptoms in schizophrenia patients. Aim: This study aimed to explore how thought disorder and form perception are related with clinical symptoms and cognitive dysfunction in first-episode schizophrenia. Setting: Forty-two patients with a first-episode of schizophrenia, schizophreniform or schizoaffective disorder were recruited from community clinics and state hospitals in the Cape Town area. Methods: Patients were assessed at baseline with the Rorschach Perceptual Thinking Index (PTI, the Positive and Negative Syndrome Scale (PANSS and the MATRICS Cognitive Consensus Battery (MCCB. Spearman correlational analyses were conducted to investigate relationships between PTI scores, PANSS factor analysis-derived domain scores and MCCB composite and subscale scores. Multiple regression models explored these relationships further. Results: Unexpectedly, poor form perception (X- % was inversely correlated with the severity of PANSS positive symptoms (r = -0.42, p = 0.02. Good form perception (XA% correlated significantly with speed of processing (r = 0.59, p < 0.01, working memory (r = 0.48, p < 0.01 and visual learning (r = 0.55, p < 0.01. PTI measures of thought disorder did not correlate significantly with PANSS symptom scores or cognitive performance. Conclusions: Form perception is associated with positive symptoms and impairment in executive function during acute psychosis. These findings suggest that there may be clinical value in including sensory-perceptual processing tasks in cognitive remediation and social cognitive training programmes for schizophrenia patients.
Ono, Kentaro; Altmann, Christian F; Matsuhashi, Masao; Mima, Tatsuya; Fukuyama, Hidenao
Perceptual grouping is the process of organizing sounds into perceptually meaningful elements. Psychological studies have found that tones presented as a regular frequency or temporal pattern are grouped according to gestalt principles, such as similarity, proximity, and good continuity. Predictive coding theory suggests that this process helps create an internal model for the prediction of sounds in a tone sequence and that an omission-related brain response reflects the violation of this prediction. However, it remains unclear which brain areas are related to this process, especially in paying attention to the stimuli. To clarify this uncertainty, the present study investigated the neural correlates of perceptual grouping effects. Using magnetoencephalography (MEG), we recorded the evoked response fields (ERFs) of amateur musicians and nonmusicians to sound omissions in tone sequences with a regular or random pattern of three different frequencies during an omission detection task. Omissions in the regular sequences were detected faster and evoked greater activity in the left Heschl's gyrus (HG), right postcentral gyrus, and bilateral superior temporal gyrus (STG) than did omissions in the irregular sequences. Additionally, an interaction between musical experience and regularity was found in the left HG/STG. Tone-evoked responses did not show this difference, indicating that the expertise effect did not reflect the superior tone processing acquired by amateur musicians due to musical training. These results suggest that perceptual grouping based on repetition of a pattern of frequencies affects the processing of omissions in tone sequences and induces more activation of the bilateral auditory cortex by violating internal models. The interaction in the left HG/STG may suggest different styles of processing for musicians and nonmusicians, although this difference was not reflected at the behavioral level. Copyright © 2014 Elsevier B.V. All rights reserved.
Gong, Mengyuan; Jia, Ke; Li, Sheng
Visual attentional selection is influenced by the value of objects. Previous studies have demonstrated that reward-associated items lead to rapid distraction and associated behavioral costs, which are difficult to override with top-down control. However, it has not been determined whether a perceptually competitive environment could render the reward-driven distraction more susceptible to top-down suppression. Here, we trained both genders of human subjects to associate two orientations with high and low magnitudes of reward. After training, we collected fMRI data while the subjects performed a categorical visual search task. The item in the reward-associated orientation served as the distractor, and the relative physical salience between the target and distractor was carefully controlled to modulate the degree of perceptual competition. The behavioral results showed faster searches in the presence of high, relative to low, reward-associated distractors. However, this effect was evident only if the physical salience of the distractor was higher than that of the target, indicating a context-dependent suppression effect of reward salience that relied on high perceptual competition. By analyzing the fMRI data in primary visual cortex, we found that the behavioral pattern of results could be predicted by the suppressed channel responses tuned to the reward-associated orientation in the distractor location, accompanied by increased responses in the midbrain dopaminergic region. Our results suggest that the learned salience of a reward plays a flexible role in solving perceptual competition, enabling the neural system to adaptively modulate the perceptual representation for behavioral optimization.SIGNIFICANCE STATEMENT The predictiveness principle in learning theory suggests that the stimulus with high predictability of reward receives priority in attentional selection. This selection bias leads to difficulties in changing approach behaviors, and thus becomes an
Michael J. Duncan; Rosanna Gibbard; Leanne M. Raymond; Peter Mundy
This study compared the physiological, perceptual and mechanical responses to kettlebell swings at different loads and swing speeds. Following familiarization 16 strength trained participants (10 males, six females, mean age ± SD = 23 ± 2.9) performed four trials: 2 min kettlebell swings with an 8 kg kettlebell at a fast cadence; 2 min kettlebell swings with an 8 kg kettlebell at a slow cadence; 4 min kettlebell swings with a 4 kg kettlebell at a fast cadence; 4 min kettlebell swings with a 4...
Rafie, Forouzan; Ghasemi, Abdollah; Zamani Jam, Azadeh; Jalali, Shahin
Motor skill impairment has been reported in many studies of autistic adolescents. The aim of this study was to examine the effect of selected physical exercise on Perceptual-motor skills in adolescents with autism. Twenty adolescents with autism that were under special education in Tehran based on their Childhood Autism Rating Scale (CARS) scores and level of abilities were selected. Measurement tool was Bruininks-Oseretsky Test of Motor Proficiency (BOTMP). Selected group motor program in this study includes motor activities, games and sports for adolescents that were performed for 10 weeks. Results showed that selected physical exercise training has significant effects on all of the variables (Pautism.
task/skill type (e.g., cognitive- quantitative reasoning skills, perceptual skills, psychomotor skills ) in order to identify which training methods...Moreover, if a user was interested in only examining part-task training for training psychomotor skills , with far transfer being the focus outcome of...studies examining methods in which to train psychomotor skills ). In sum, this capability enables users to view and examine summary information for only
Alice Kitty Lagas
Full Text Available The selective serotonin reuptake inhibitor fluoxetine significantly enhances adult visual cortex plasticity within the rat. This effect is related to decreased gamma-aminobutyric acid (GABA mediated inhibition and identifies fluoxetine as a potential agent for enhancing plasticity in the adult human brain. We tested the hypothesis that fluoxetine would enhance visual perceptual learning of a motion direction discrimination (MDD task in humans. We also investigated 1 the effect of fluoxetine on visual and motor cortex excitability and 2 the impact of increased GABA mediated inhibition following a single dose of triazolam on post-training MDD task performance. Within a double blind, placebo controlled design, 20 healthy adult participants completed a 19-day course of fluoxetine (n = 10, 20mg per day or placebo (n = 10. Participants were trained on the MDD task over the final five days of fluoxetine administration. Accuracy for the trained MDD stimulus and an untrained MDD stimulus configuration was assessed before and after training, after triazolam and one week after triazolam. Motor and visual cortex excitability was measured using transcranial magnetic stimulation. Fluoxetine did not enhance the magnitude or rate of perceptual learning and full transfer of learning to the untrained stimulus was observed for both groups. After training was complete, trazolam had no effect on trained task performance but significantly impaired untrained task performance. No consistent effects of fluoxetine on cortical excitability were observed. The results do not support the hypothesis that fluoxetine can enhance learning in humans. However, the specific effect of triazolam on MDD task performance for the untrained stimulus suggests that learning and learning transfer relay on dissociable neural mechanisms.
Sundareswara, Rashmi; Schrater, Paul R
Perceptual multistability refers to the phenomenon of spontaneous perceptual switching between two or more likely interpretations of an image. Although frequently explained by processes of adaptation or hysteresis, we show that perceptual switching can arise as a natural byproduct of perceptual decision making based on probabilistic (Bayesian) inference, which interprets images by combining probabilistic models of image formation with knowledge of scene regularities. Empirically, we investigated the effect of introducing scene regularities on Necker cube bistability by flanking the Necker cube with fields of unambiguous cubes that are oriented to coincide with one of the Necker cube percepts. We show that background cubes increase the time spent in percepts most similar to the background. To characterize changes in the temporal dynamics of the perceptual alternations beyond percept durations, we introduce Markov Renewal Processes (MRPs). MRPs provide a general mathematical framework for describing probabilistic switching behavior in finite state processes. Additionally, we introduce a simple theoretical model consistent with Bayesian models of vision that involves searching for good interpretations of an image by sampling a posterior distribution coupled with a decay process that favors recent to old interpretations. The model has the same quantitative characteristics as our human data and variation in model parameters can capture between-subject variation. Because the model produces the same kind of stochastic process found in human perceptual behavior, we conclude that multistability may represent an unavoidable by-product of normal perceptual (Bayesian) decision making with ambiguous images.
Ruchay, Alexey; Kober, Vitaly; Yavtushenko, Evgeniya
In this paper, we propose a perceptual image hash algorithm based on cascade algorithm, which can be applied in image authentication, retrieval, and indexing. Image perceptual hash uses for image retrieval in sense of human perception against distortions caused by compression, noise, common signal processing and geometrical modifications. The main disadvantage of perceptual hash is high time expenses. In the proposed cascade algorithm of image retrieval initializes with short hashes, and then a full hash is applied to the processed results. Computer simulation results show that the proposed hash algorithm yields a good performance in terms of robustness, discriminability, and time expenses.
Savard, Josée; Ivers, Hans; Savard, Marie-Hélène; Morin, Charles M
To assess the short-term efficacy of a video-based cognitive behavioral therapy for insomnia (CBT-I) as compared to a professionally administered CBT-I and to a no-treatment group. Randomized controlled trial. Radio-oncology department of a public hospital affiliated with Université Laval (CHU de Québec). Two hundred forty-two women with breast cancer who had received radiation therapy in the past 18 mo and who had insomnia symptoms or were using hypnotic medications were randomized to: (1) professionally administered CBT-I (PCBT-I; n = 81); (2) video-based CBT-I (VCBT-I; n = 80); and (3) no treatment (CTL; n = 81). PCBT-I composed of six weekly, individual sessions of approximately 50 min; VCBT-I composed of a 60-min animated video + six booklets. Insomnia Severity Index (ISI) total score and sleep parameters derived from a daily sleep diary and actigraphy, collected at pretreatment and posttreatment. PCBT-I and VCBT-I were associated with significantly greater sleep improvements, assessed subjectively, as compared to CTL. However, relative to VCBT-I, PCBT-I was associated with significantly greater improvements of insomnia severity, early morning awakenings, depression, fatigue, and dysfunctional beliefs about sleep. The remission rates of insomnia (ISI behavioral therapy for insomnia (CBT-I) using a video format appears to be a valuable treatment option, but face-to-face sessions remain the optimal format for administering CBT-I efficaciously in patients with breast cancer. Self-help interventions for insomnia may constitute an appropriate entry level as part of a stepped care model. ClinicalTrials.gov Identifier: NCT00674830. Savard J, Ivers H, Savard MH, Morin CM. Is a video-based cognitive behavioral therapy for insomnia as efficacious as a professionally administered treatment in breast cancer? Results of a randomized controlled trial.
Memmert, D.; Hagemann, N.; Althoetmar, R.; Geppert, S.; Seiler, D.
This study uses three experiments with different kinds of training conditions to investigate the "easy-to-hard" principle, context interference conditions, and feedback effects for learning anticipatory skills in badminton. Experiment 1 (N = 60) showed that a training program that gradually increases the difficulty level has no advantage over the…
Magaly M Blas
Full Text Available Although many men who have sex with men (MSM in Peru are unaware of their HIV status, they are frequent users of the Internet, and can be approached by that medium for promotion of HIV testing.We conducted an online randomized controlled trial to compare the effect of HIV-testing motivational videos versus standard public health text, both offered through a gay website. The videos were customized for two audiences based on self-identification: either gay or non-gay men. The outcomes evaluated were 'intention to get tested' and 'HIV testing at the clinic.'In the non-gay identified group, 97 men were randomly assigned to the video-based intervention and 90 to the text-based intervention. Non-gay identified participants randomized to the video-based intervention were more likely to report their intention of getting tested for HIV within the next 30 days (62.5% vs. 15.4%, Relative Risk (RR: 2.77, 95% Confidence Interval (CI: 1.42-5.39. After a mean of 125.5 days of observation (range 42-209 days, 11 participants randomized to the video and none of the participants randomized to text attended our clinic requesting HIV testing (p = 0.001. In the gay-identified group, 142 men were randomized to the video-based intervention and 130 to the text-based intervention. Gay-identified participants randomized to the video were more likely to report intentions of getting an HIV test within 30 days, although not significantly (50% vs. 21.6%, RR: 1.54, 95% CI: 0.74-3.20. At the end of follow up, 8 participants who watched the video and 10 who read the text visited our clinic for HIV testing (Hazard Ratio: 1.07, 95% CI: 0.40-2.85.This study provides some evidence of the efficacy of a video-based online intervention in improving HIV testing among non-gay-identified MSM in Peru. This intervention may be adopted by institutions with websites oriented to motivate HIV testing among similar MSM populations.Clinicaltrials.gov NCT00751192.
Rettberg, Jill Walker
Video-based communication is increasingly common online. This article looks at the hand signs that are used in lip-syncing videos on the app musical.ly and argues that they constitute a codified, non-verbal language of pictograms that is equivalent to emoji in text-based communication. Seeing the lip-syncing videos as performances allows us to situate the hand signs as the latest development in a long history of formalized gestures for theatrical performance. By recognizing this emergent gest...
Ritterband-Rosenbaum, A.; Christensen, M. S.; Nielsen, J. B.
Children with cerebral palsy (CP) show alteration of perceptual and cognitive abilities in addition to motor and sensory deficits, which may include altered sense of agency. The aim of this study was to evaluate whether 20 weeks of internet-based motor, perceptual and cognitive training enhances the ability of CP children to determine whether they…
Van Meel, Chayenne; Daniels, Nicky; de Beeck, Hans Op; Baeck, Annelies
During perceptual learning the visual representations in the brain are altered, but these changes' causal role has not yet been fully characterized. We used transcranial direct current stimulation (tDCS) to investigate the role of higher visual regions in lateral occipital cortex (LO) in perceptual learning with complex objects. We also investigated whether object learning is dependent on the relevance of the objects for the learning task. Participants were trained in two tasks: object recognition using a backward masking paradigm and an orientation judgment task. During both tasks, an object with a red line on top of it were presented in each trial. The crucial difference between both tasks was the relevance of the object: the object was relevant for the object recognition task, but not for the orientation judgment task. During training, half of the participants received anodal tDCS stimulation targeted at the lateral occipital cortex (LO). Afterwards, participants were tested on how well they recognized the trained objects, the irrelevant objects presented during the orientation judgment task and a set of completely new objects. Participants stimulated with tDCS during training showed larger improvements of performance compared to participants in the sham condition. No learning effect was found for the objects presented during the orientation judgment task. To conclude, this study suggests a causal role of LO in relevant object learning, but given the rather low spatial resolution of tDCS, more research on the specificity of this effect is needed. Further, mere exposure is not sufficient to train object recognition in our paradigm.
Kim, Youngjun; van Velsen, Martin; Hill, Jr, Randall W
An important characteristic of a virtual human is the ability to direct its perceptual attention to entities and areas in a virtual environment in a manner that appears believable and serves a functional purpose...
Cortese, Aurelio; Amano, Kaoru; Koizumi, Ai; Kawato, Mitsuo; Lau, Hakwan
A central controversy in metacognition studies concerns whether subjective confidence directly reflects the reliability of perceptual or cognitive processes, as suggested by normative models based on the assumption that neural computations are generally optimal. This view enjoys popularity in the computational and animal literatures, but it has also been suggested that confidence may depend on a late-stage estimation dissociable from perceptual processes. Yet, at least in humans, experimental tools have lacked the power to resolve these issues convincingly. Here, we overcome this difficulty by using the recently developed method of decoded neurofeedback (DecNef) to systematically manipulate multivoxel correlates of confidence in a frontoparietal network. Here we report that bi-directional changes in confidence do not affect perceptual accuracy. Further psychophysical analyses rule out accounts based on simple shifts in reporting strategy. Our results provide clear neuroscientific evidence for the systematic dissociation between confidence and perceptual performance, and thereby challenge current theoretical thinking. PMID:27976739
Uhlhaas, Peter J; Mishara, Aaron L
.... In contrast, general consensus has viewed dysfunctions in basic perceptual processes to be relatively unimportant in the explanation of more complex aspects of the disorder, including changes in self...
STEENKAMP, JBEM; VANTRIJP, HCM; TENBERGE, JMF
The authors describe a compositional perceptual mapping procedure, unrestricted attribute-elicitation mapping (UAM), which allows consumers to describe and rate the brands in their own terminology and thus relaxes the restrictive assumptions of traditional compositional mapping techniques regarding
Uhlhaas, Peter J; Mishara, Aaron L
...-experience and the development of symptoms such as delusions. We present evidence from phenomenology and cognitive neuroscience that changes in the perceptual field in schizophrenia may represent a core impairment...
Full Text Available This paper proposes a blind authentication scheme to identify duplicated regions for copy-move forgery based on perceptual hashing and package clustering algorithms. For all fixed-size image blocks in suspicious images, discrete cosine transform (DCT is used to obtain their DCT coefficient matrixes. Their perceptual hash matrixes and perceptual hash feature vectors are orderly addressed. Moreover, a package clustering algorithm is proposed to replace traditional lexicographic order algorithms for improving the detection precision. Similar blocks can be identified by matching the perceptual hash feature vectors in each package and its adjacent package. The experimental results show that the proposed scheme can locate irregular tampered regions and multiple duplicated regions in suspicious images although they are distorted by some hybrid trace hiding operations, such as adding white Gaussian noise and Gaussian blurring, adjusting contrast ratio, luminance, and hue, and their hybrid operations.
Mossio, Matteo; Taraborelli, Dario
Ecological and sensorimotor theories of perception build on the notion of action-dependent invariants as the basic structures underlying perceptual capacities. In this paper we contrast the assumptions these theories make on the nature of perceptual information modulated by action. By focusing on the question, how movement specifies perceptual information, we show that ecological and sensorimotor theories endorse substantially different views about the role of action in perception. In particular we argue that ecological invariants are characterized with reference to transformations produced in the sensory array by movement: such invariants are transformation-specific but do not imply motor-specificity. In contrast, sensorimotor theories assume that perceptual invariants are intrinsically tied to specific movements. We show that this difference leads to different empirical predictions and we submit that the distinction between motor equivalence and motor-specificity needs further clarification in order to provide a more constrained account of action/perception relations.
Adank, Patricia Martine
In sociolinguistics, language variation in vowel sounds is typically studied using phonetic transcription. Phonetic transcription is carried out by expert listeners, who are capable of perceptually separating (socio-) linguistic variation from anatomical/physiological speaker-related
Nittrouer, Susan; Lowenstein, Joanna H.
The ability to recognize speech involves sensory, perceptual, and cognitive processes. For much of the history of speech perception research, investigators have focused on the first and third of these, asking how much and what kinds of sensory information are used by normal and impaired listeners, as well as how effective amounts of that information are altered by “top-down” cognitive processes. This experiment focused on perceptual processes, asking what accounts for how the sensory informat...
The picture superiority effect, i.e. better memory for pictures than for corresponding words, has been variously ascribed to a conceptual or a perceptual processing advantage. The present study aimed to disentangle perceptual and conceptual contributions. Pictures and words were tested for recognition in both their original formats and translated into participants´ second language. Multinomial Processing Tree (Batchelder & Riefer, 1999) and MINERVA (Hintzman, 1984) models were fitted to t...
Rebecca eRienhoff; Melissa eHopwood; Lennart eFischer; Bernd eStrauss; Joe eBaker; Joerg eSchorer
The quiet eye is a perceptual skill associated with expertise and superior performance; however, little is known about the transfer of quiet eye across domains. We attempted to replicate previous skill-based differences in quiet eye and investigated whether transfer of motor and perceptual skills occurs between similar tasks. Throwing accuracy and quiet eye duration for skilled and less-skilled basketball players were examined in basketball free throw shooting and the transfer task of dart th...
Theodore, Rachel M.; Schmidt, Anna M.
Previous research suggests a perceptual bias exists for native phonotactics [D. Massaro and M. Cohen, Percept. Psychophys. 34, 338-348 (1983)] such that listeners report nonexistent segments when listening to stimuli that violate native phonotactics [E. Dupoux, K. Kakehi, Y. Hirose, C. Pallier, and J. Mehler, J. Exp. Psychol.: Human Percept. Perform. 25, 1568-1578 (1999)]. This study investigated how native-language experience affects second language processing, focusing on how native Spanish speakers perceive the English clusters /st/, /sp/, and /sk/, which represent phonotactically illegal forms in Spanish. To preserve native phonotactics, Spanish speakers often produce prothetic vowels before English words beginning with /s/ clusters. Is the influence of native phonotactics also present in the perception of illegal clusters? A stimuli continuum ranging from no vowel (e.g., ``sku'') to a full vowel (e.g., ``esku'') before the cluster was used. Four final vowel contexts were used for each cluster, resulting in 12 sCV and 12 VsCV nonword endpoints. English and Spanish listeners were asked to discriminate between pairs differing in vowel duration and to identify the presence or absence of a vowel before the cluster. Results will be discussed in terms of implications for theories of second language speech perception.
Koval, O.; Voloshynovskiy, S.; Bas, P.; Cayre, F.
Perceptual hashing has to deal with the constraints of robustness, accuracy and security. After modeling the process of hash extraction and the properties involved in this process, two different security threats are studied, namely the disclosure of the secret feature space and the tampering of the hash. Two different approaches for performing robust hashing are presented: Random-Based Hash (RBH) where the security is achieved using a random projection matrix and Content-Based Hash (CBH) were the security relies on the difficulty to tamper the hash. As for digital watermarking, different security setups are also devised: the Batch Hash Attack, the Group Hash Attack, the Unique Hash Attack and the Sensitivity Attack. A theoretical analysis of the information leakage in the context of Random-Based Hash is proposed. Finally, practical attacks are presented: (1) Minor Component Analysis is used to estimate the secret projection of Random-Based Hashes and (2) Salient point tampering is used to tamper the hash of Content-Based Hashes systems.
Leong, Grace W S; Gorrie, Catherine A; Ng, Karl; Rutkowski, Sue; Waite, Phil M E
To investigate inter-rater and intra-rater reliability of electrical perceptual threshold (EPT) testing in assessing somatosensory function in healthy volunteers. Prospective experimental. Hospital-based spinal cord injuries unit. Cutaneous electrical stimulation of 4 dermatomes at ASIA sensory key points (C3, T1, L3, and S2) was performed on 40 control subjects. The lowest ascending stimulus intensity at which sensation was perceived was recorded as the EPT. Mean EPT values for each dermatome, as determined by 2 testers at 2 time points, were examined and plotted against a normative template. Differences and associations between intra- and inter-rater measurements and left-right measurements were studied. EPT results for 2 people with spinal cord injuries were also examined. EPT measurements from left and right sides, obtained from the 2 time points and 2 testers, were found to be strongly associated, with the exception of left and right side measurements at the S2 dermatome. No significant differences in the mean EPT for tester or time period were found. The intra- and inter-rater reliability was good for all dermatomes tested. Mean EPT measurements fell within the range of a normative template at each of the 4 dermatomes tested. EPT is an objective, reproducible, and quantifiable method of assessing sensation in a control group. However, caution should be applied in certain dermatomes such as S2, where there was large variation between left and right side measurements.
Bang, Duhyeon; Shim, Hyunjung
A depth camera is widely used in various applications because it provides a depth image of the scene in real time. However, due to the limited power consumption, the depth camera presents severe noises, incapable of providing the high quality 3D data. Although the smoothness prior is often employed to subside the depth noise, it discards the geometric details so to degrade the distance resolution and hinder achieving the realism in 3D contents. In this paper, we propose a perceptual-based depth image enhancement technique that automatically recovers the depth details of various textures, using a statistical framework inspired by human mechanism of perceiving surface details by texture priors. We construct the database composed of the high quality normals. Based on the recent studies in human visual perception (HVP), we select the pattern density as a primary feature to classify textures. Upon the classification results, we match and substitute the noisy input normals with high quality normals in the database. As a result, our method provides the high quality depth image preserving the surface details. We expect that our work is effective to enhance the details of depth image from 3D sensors and to provide a high-fidelity virtual reality experience.
Abrahamyan, Arman; Silva, Laura Luz; Dakin, Steven C.; Gardner, Justin L.
When making choices under conditions of perceptual uncertainty, past experience can play a vital role. However, it can also lead to biases that worsen decisions. Consistent with previous observations, we found that human choices are influenced by the success or failure of past choices even in a standard two-alternative detection task, where choice history is irrelevant. The typical bias was one that made the subject switch choices after a failure. These choice history biases led to poorer performance and were similar for observers in different countries. They were well captured by a simple logistic regression model that had been previously applied to describe psychophysical performance in mice. Such irrational biases seem at odds with the principles of reinforcement learning, which would predict exquisite adaptability to choice history. We therefore asked whether subjects could adapt their irrational biases following changes in trial order statistics. Adaptability was strong in the direction that confirmed a subject’s default biases, but weaker in the opposite direction, so that existing biases could not be eradicated. We conclude that humans can adapt choice history biases, but cannot easily overcome existing biases even if irrational in the current context: adaptation is more sensitive to confirmatory than contradictory statistics. PMID:27330086
Victor, Jonathan D; Thengone, Daniel J; Rizvi, Syed M; Conte, Mary M
Local image statistics are important for visual analysis of textures, surfaces, and form. There are many kinds of local statistics, including those that capture luminance distributions, spatial contrast, oriented segments, and corners. While sensitivity to each of these kinds of statistics have been well-studied, much less is known about visual processing when multiple kinds of statistics are relevant, in large part because the dimensionality of the problem is high and different kinds of statistics interact. To approach this problem, we focused on binary images on a square lattice - a reduced set of stimuli which nevertheless taps many kinds of local statistics. In this 10-parameter space, we determined psychophysical thresholds to each kind of statistic (16 observers) and all of their pairwise combinations (4 observers). Sensitivities and isodiscrimination contours were consistent across observers. Isodiscrimination contours were elliptical, implying a quadratic interaction rule, which in turn determined ellipsoidal isodiscrimination surfaces in the full 10-dimensional space, and made predictions for sensitivities to complex combinations of statistics. These predictions, including the prediction of a combination of statistics that was metameric to random, were verified experimentally. Finally, check size had only a mild effect on sensitivities over the range from 2.8 to 14min, but sensitivities to second- and higher-order statistics was substantially lower at 1.4min. In sum, local image statistics form a perceptual space that is highly stereotyped across observers, in which different kinds of statistics interact according to simple rules. Copyright © 2015 Elsevier Ltd. All rights reserved.
Moradi, Zargol; Sui, Jie; Hewstone, Miles; Humphreys, Glyn W
We report a novel effect of in-group bias on a task requiring simple perceptual matching of stimuli. Football fans were instructed to associate the badges of their favorite football team (in-group), a rival team (out-group), and neutral teams with simple geometric shapes. Responses to matching in-group stimuli were more efficient, and discriminability was enhanced, as compared to out-group stimuli (rival and neutral)-a result that occurred even when participants responded only to the (equally familiar) geometric shapes. Across individuals, the in-group bias on shape matching was correlated with measures of group satisfaction, and similar results were found when football fans performed the task, in the context of both the football ground and a laboratory setting. We also observed effects of in-group bias on the response criteria in some but not all of the experiments. In control studies, the advantage for in-group stimuli was not found in an independent sample of participants who were not football fans. This indicates that there was not an intrinsic advantage for the stimuli that were "in-group" for football fans. Also, performance did not differ for familiar versus unfamiliar stimuli without in-group associations. These findings indicate that group identification can affect simple shape matching.
Behler, Oliver; Breckel, Thomas P K; Thiel, Christiane M
Several studies provide evidence that nicotine alleviates the detrimental effects of distracting sensory stimuli. It is been suggested that nicotine may either act as a stimulus filter that prevents irrelevant stimuli entering awareness or by enhancing the attentional focus to relevant stimuli via a boost in processing capacity. To differentiate between these two accounts, we administered nicotine to healthy non-smokers and investigated distractor interference in a visual search task with low and high perceptual load to tax processing capacity. Thirty healthy non-smokers received either 7 mg transdermal nicotine or a matched placebo in a double blind within subject design 1 h prior to performing the visual search task with different fixation distractors. Nicotine reduced interference of incongruent distractors, but only under low-load conditions, where distractor effects were large. No effects of nicotine were observed under high-load conditions. Highly distractible subjects showed the largest effects of nicotine. The findings suggest that nicotine acts primarily as a stimulus filter that prevents irrelevant stimuli from entering awareness in situations of high distractor interference.
Helsen, Werner; Bultynck, Jean-Baptist
The aim of this study was to examine the physical and perceptual-cognitive demands imposed on UEFA top-class referees and assistant referees during the final round of the Euro 2000 Championship. To investigate the physical workload, the heart rates during matches were monitored by short-range radio telemetry and translated to different workloads expressed as a percentage of maximal heart rate. For measurement of the perceptual-cognitive workload, video-recordings of games were used to obtain the average number of observable decisions taken by a referee. On average, referees and assistant referees performed the matches at 85 +/- 5% and 77 +/- 7% of their maximal heart rate, respectively. Over the 31 games, the mean number of observable decisions was 137 (range 104-162), 64% of which were based on communication with the assistant referees and/or the fourth official. To optimize the physical preparation of top-class match officials, the results of this study support the application of intensive and intermittent training sessions, which should place priority on high-intensity aerobic stimuli. In addition, video training is discussed as an additional method for improving match officials' decision making.
Baumann, Oliver; Borra, Ronald J; Bower, James M; Cullen, Kathleen E; Habas, Christophe; Ivry, Richard B; Leggio, Maria; Mattingley, Jason B; Molinari, Marco; Moulton, Eric A; Paulin, Michael G; Pavlova, Marina A; Schmahmann, Jeremy D; Sokolov, Arseny A
Various lines of evidence accumulated over the past 30 years indicate that the cerebellum, long recognized as essential for motor control, also has considerable influence on perceptual processes. In this paper, we bring together experts from psychology and neuroscience, with the aim of providing a succinct but comprehensive overview of key findings related to the involvement of the cerebellum in sensory perception. The contributions cover such topics as anatomical and functional connectivity, evolutionary and comparative perspectives, visual and auditory processing, biological motion perception, nociception, self-motion, timing, predictive processing, and perceptual sequencing. While no single explanation has yet emerged concerning the role of the cerebellum in perceptual processes, this consensus paper summarizes the impressive empirical evidence on this problem and highlights diversities as well as commonalities between existing hypotheses. In addition to work with healthy individuals and patients with cerebellar disorders, it is also apparent that several neurological conditions in which perceptual disturbances occur, including autism and schizophrenia, are associated with cerebellar pathology. A better understanding of the involvement of the cerebellum in perceptual processes will thus likely be important for identifying and treating perceptual deficits that may at present go unnoticed and untreated. This paper provides a useful framework for further debate and empirical investigations into the influence of the cerebellum on sensory perception.
Full Text Available Medical rehabilitation involving behavioral training can produce highly successful outcomes, but those successes are obtained at the cost of long periods of often tedious training, reducing compliance. By contrast, arcade-style video games can be entertaining and highly motivating. We examine here the impact of video game play on contiguous perceptual training. We alternated several periods of auditory pure-tone frequency discrimination (FD with the popular spatial visual-motor game Tetris played in silence. Tetris play alone did not produce any auditory or cognitive benefits. However, when alternated with FD training it enhanced learning of FD and auditory working memory. The learning-enhancing effects of Tetris play cannot be explained simply by the visual-spatial training involved, as the effects were gone when Tetris play was replaced with another visual-spatial task using Tetris-like stimuli but not incorporated into a game environment. The results indicate that game play enhances learning and transfer of the contiguous auditory experiences, pointing to a promising approach for increasing the efficiency and applicability of rehabilitative training.
Zhang, Yu-Xuan; Tang, Ding-Lan; Moore, David R.; Amitay, Sygal
Medical rehabilitation involving behavioral training can produce highly successful outcomes, but those successes are obtained at the cost of long periods of often tedious training, reducing compliance. By contrast, arcade-style video games can be entertaining and highly motivating. We examine here the impact of video game play on contiguous perceptual training. We alternated several periods of auditory pure-tone frequency discrimination (FD) with the popular spatial visual-motor game Tetris played in silence. Tetris play alone did not produce any auditory or cognitive benefits. However, when alternated with FD training it enhanced learning of FD and auditory working memory. The learning-enhancing effects of Tetris play cannot be explained simply by the visual-spatial training involved, as the effects were gone when Tetris play was replaced with another visual-spatial task using Tetris-like stimuli but not incorporated into a game environment. The results indicate that game play enhances learning and transfer of the contiguous auditory experiences, pointing to a promising approach for increasing the efficiency and applicability of rehabilitative training. PMID:28701989
Zhang, Yu-Xuan; Tang, Ding-Lan; Moore, David R; Amitay, Sygal
Medical rehabilitation involving behavioral training can produce highly successful outcomes, but those successes are obtained at the cost of long periods of often tedious training, reducing compliance. By contrast, arcade-style video games can be entertaining and highly motivating. We examine here the impact of video game play on contiguous perceptual training. We alternated several periods of auditory pure-tone frequency discrimination (FD) with the popular spatial visual-motor game Tetris played in silence. Tetris play alone did not produce any auditory or cognitive benefits. However, when alternated with FD training it enhanced learning of FD and auditory working memory. The learning-enhancing effects of Tetris play cannot be explained simply by the visual-spatial training involved, as the effects were gone when Tetris play was replaced with another visual-spatial task using Tetris-like stimuli but not incorporated into a game environment. The results indicate that game play enhances learning and transfer of the contiguous auditory experiences, pointing to a promising approach for increasing the efficiency and applicability of rehabilitative training.
Wisniewski, Matthew G; Radell, Milen L; Church, Barbara A; Mercado, Eduardo
Individuals learn to classify percepts effectively when the task is initially easy and then gradually increases in difficulty. Some suggest that this is because easy-to-discriminate events help learners focus attention on discrimination-relevant dimensions. Here, we tested whether such attentional-spotlighting accounts are sufficient to explain easy-to-hard effects in auditory perceptual learning. In two experiments, participants were trained to discriminate periodic, frequency-modulated (FM) tones in two separate frequency ranges (300-600 Hz or 3000-6000 Hz). In one frequency range, sounds gradually increased in similarity as training progressed. In the other, stimulus similarity was constant throughout training. After training, participants showed better performance in their progressively trained frequency range, even though the discrimination-relevant dimension across ranges was the same. Learning theories that posit experience-dependent changes in stimulus representations and/or the strengthening of associations with differential responses, predict the observed specificity of easy-to-hard effects, whereas attentional-spotlighting theories do not. Calibrating the difficulty and temporal sequencing of training experiences to support more incremental representation-based learning can enhance the effectiveness of practice beyond any benefits gained from explicitly highlighting relevant dimensions.
Matthew G Wisniewski
Full Text Available Individuals learn to classify percepts effectively when the task is initially easy and then gradually increases in difficulty. Some suggest that this is because easy-to-discriminate events help learners focus attention on discrimination-relevant dimensions. Here, we tested whether such attentional-spotlighting accounts are sufficient to explain easy-to-hard effects in auditory perceptual learning. In two experiments, participants were trained to discriminate periodic, frequency-modulated (FM tones in two separate frequency ranges (300-600 Hz or 3000-6000 Hz. In one frequency range, sounds gradually increased in similarity as training progressed. In the other, stimulus similarity was constant throughout training. After training, participants showed better performance in their progressively trained frequency range, even though the discrimination-relevant dimension across ranges was the same. Learning theories that posit experience-dependent changes in stimulus representations and/or the strengthening of associations with differential responses, predict the observed specificity of easy-to-hard effects, whereas attentional-spotlighting theories do not. Calibrating the difficulty and temporal sequencing of training experiences to support more incremental representation-based learning can enhance the effectiveness of practice beyond any benefits gained from explicitly highlighting relevant dimensions.
Full Text Available Perceptual learning has been shown to produce an improvement of visual acuity (VA and contrast sensitivity (CS both in subjects with amblyopia and refractive defects such as myopia or presbyopia. Transcranial random noise stimulation (tRNS has proven to be efficacious in accelerating neural plasticity and boosting perceptual learning in healthy participants. In this study we investigated whether a short behavioural training regime using a contrast detection task combined with online tRNS was as effective in improving visual functions in participants with mild myopia compared to a two-month behavioural training regime without tRNS (Camilleri et al., 2014. After two weeks of perceptual training in combination with tRNS, participants showed an improvement of 0.15 LogMAR in uncorrected VA (UCVA that was comparable with that obtained after eight weeks of training with no tRNS, and an improvement in uncorrected CS (UCCS at various spatial frequencies (whereas no UCCS improvement was seen after eight weeks of training with no tRNS. On the other hand, a control group that trained for two weeks without stimulation did not show any significant UCVA or UCCS improvement. These results suggest that the combination of behavioural and neuromodulatory techniques can be fast and efficacious in improving sight in individuals with mild myopia.
Forsyth, Peta; Pumpa, Kate; Knight, Emma; Miller, Joanna
To investigate the physiological and perceptual effects of three precooling strategies during pre-exercise rest in athletes with a spinal cord injury (SCI). Randomized, counterbalanced. Participants were precooled, then rested for 60 minutes (22.7 ± 0.2°C, 64.2 ± 2.6%RH). National Wheelchair Basketball Training Centre, Australia. Sixteen wheelchair basketball athletes with a SCI. Participants were precooled through; 1) 10 minutes of 15.8°C cold water immersion (CWI), 2) ingestion of 6.8 g/kg-1 of slushie (S) from sports drink; 3) ingestion of 6.8 g/kg-1 of slushie with application of iced towels to the legs, torso and back/arms (ST); or 4) ingestion of 6.8 g/kg-1 of room temperature (22.3°C) sports drink (CON). Core temperature (Tgi), skin temperature (Tsk), heart rate (HR), and thermal and gastrointestinal comfort. Following CWI, a significant reduction in Tgi was observed compared to CON, with a greatest reduction of 1.58°C occurring 40 minutes post-cooling (95% CI [1.07, 2.10]). A significant reduction in Tgi following ST compared to CON was also observed at 20 minutes (0.56°C; [0.03, 1.09]) and 30 minutes (0.56°C; [0.04, 1.09]) post-cooling. Additionally, a significant interaction between impairment level and time was observed for Tgi and HR, demonstrating athletes with a higher level of impairment experienced a greater reduction in HR and significant decrease in rate of decline in Tgi, compared to lesser impaired athletes. CWI and ST can effectively lower body temperature in athletes with a SCI, and may assist in tolerating warm conditions.
Marozeau, Jeremy; McDermott, Hugh J; Swanson, Brett A; McKay, Colette M
In today's cochlear implant (CI) systems, the monopolar (MP) electrode configuration is the most commonly used stimulation mode, requiring only a single current source. However, with an implant that will allow simultaneous activation of multiple independent current sources, it is possible to implement an all-polar (AP) stimulation mode designed to create a focused electrical field. The goal of this experiment was to study the potential benefits of this all-polar mode for reducing uncontrolled electrode interactions compared with the monopolar mode. The five participants who took part in the study were implanted with a research device that was connected via a percutaneous connector to a benchtop stimulator providing 22 independent current sources. The perceptual effects of the AP mode were tested in three experiments. In Experiment 1, the current level difference between loudness-matched sequential and simultaneous stimuli composed of 2 spatially separated pulse trains was measured as function of the electrode separation. Results indicated a strong current-summation interaction for simultaneous stimuli in the MP mode for separations up to at least 4.8 mm. No significant interaction was found in the AP mode beyond a separation of 2.4 mm. In Experiment 2, a forward-masking paradigm was used with fixed equally loud probes in AP and MP modes, and AP maskers presented on different electrode positions. Results indicated a similar spatial masking pattern between modes. In Experiment 3, subjects were asked to discriminate between across-electrode temporal delays. It was hypothesized that discrimination would decrease with electrode separation faster in AP compared to MP modes. However, results showed no difference between the two modes. Overall, the results indicated that the AP mode produced less current spread than MP mode but did not lead to a significant advantage in terms of spread of neuronal excitation at equally loud levels.
Gavin M Bidelman
Full Text Available Psychophysiological evidence suggests that music and language are intimately coupled such that experience/training in one domain can influence processing required in the other domain. While the influence of music on language processing is now well-documented, evidence of language-to-music effects have yet to be firmly established. Here, using a cross-sectional design, we compared the performance of musicians to that of tone-language (Cantonese speakers on tasks of auditory pitch acuity, music perception, and general cognitive ability (e.g., fluid intelligence, working memory. While musicians demonstrated superior performance on all auditory measures, comparable perceptual enhancements were observed for Cantonese participants, relative to English-speaking nonmusicians. These results provide evidence that tone-language background is associated with higher auditory perceptual performance for music listening. Musicians and Cantonese speakers also showed superior working memory capacity relative to nonmusician controls, suggesting that in addition to basic perceptual enhancements, tone-language background and music training might also be associated with enhanced general cognitive abilities. Our findings support the notion that tone language speakers and musically trained individuals have higher performance than English-speaking listeners for the perceptual-cognitive processing necessary for basic auditory as well as complex music perception. These results illustrate bidirectional influences between the domains of music and language.
Bidelman, Gavin M; Hutka, Stefanie; Moreno, Sylvain
Psychophysiological evidence suggests that music and language are intimately coupled such that experience/training in one domain can influence processing required in the other domain. While the influence of music on language processing is now well-documented, evidence of language-to-music effects have yet to be firmly established. Here, using a cross-sectional design, we compared the performance of musicians to that of tone-language (Cantonese) speakers on tasks of auditory pitch acuity, music perception, and general cognitive ability (e.g., fluid intelligence, working memory). While musicians demonstrated superior performance on all auditory measures, comparable perceptual enhancements were observed for Cantonese participants, relative to English-speaking nonmusicians. These results provide evidence that tone-language background is associated with higher auditory perceptual performance for music listening. Musicians and Cantonese speakers also showed superior working memory capacity relative to nonmusician controls, suggesting that in addition to basic perceptual enhancements, tone-language background and music training might also be associated with enhanced general cognitive abilities. Our findings support the notion that tone language speakers and musically trained individuals have higher performance than English-speaking listeners for the perceptual-cognitive processing necessary for basic auditory as well as complex music perception. These results illustrate bidirectional influences between the domains of music and language.
Full Text Available According to perceptual load theory (Lavie, 2005 distractor interference is determined by the availability of attentional resources. If target processing does not exhaust resources (with low perceptual load distractor processing will take place resulting in interference with a primary task; however when target processing uses-up attentional capacity (with high perceptual load interference can be avoided. An alternative account (Tsal & Benoni, 2010 suggests that perceptual load effects can be based on distractor dilution by the mere presence of additional neutral items in high load displays so that the effect is not driven by the amount of attention resources required for target processing. Here we tested whether patients with unilateral neglect or extinction would show dilution effects from neutral items in their contralesional (neglected/extinguished field, even though these items do not impose increased perceptual load on the target and at the same time attract reduced attentional resources compared to stimuli in the ipsilesional field. Thus, such items do not affect the amount of attention resources available for distractor processing. We found that contralesional neutral elements can eliminate distractor interference as strongly as centrally presented ones in neglect/extinction patients, despite contralesional items being less well attended. The data are consistent with an account in terms of perceptual dilution of distracters rather than available resources for distractor processing. We conclude that distractor dilution can underlie the elimination of distractor interference in visual displays.
Sheridan, Heather; Reingold, Eyal M
The present study used eye tracking methodology to examine rereading benefits for spatially transformed text. Eye movements were monitored while participants read the same target word twice, in two different low-constraint sentence frames. The congruency of perceptual processing was manipulated by either applying the same type of transformation to the word during the first and second presentations (i.e., the congruent condition), or employing two different types of transformations across the two presentations of the word (i.e., the incongruent condition). Perceptual specificity effects were demonstrated such that fixation times for the second presentation of the target word were shorter for the congruent condition compared to the incongruent condition. Moreover, we demonstrated an additional perceptually non-specific effect such that second reading fixation times were shorter for the incongruent condition relative to a baseline condition that employed a normal typography (i.e., non-transformed) during the first presentation and a transformation during the second presentation. Both of these effects (i.e., perceptually specific and perceptually non-specific) were similar in magnitude for high and low frequency words, and both effects persisted across a 1 week lag between the first and second readings. We discuss the present findings in the context of the distinction between conscious and unconscious memory, and the distinction between perceptually versus conceptually driven processing. Copyright © 2012 Elsevier Inc. All rights reserved.
Victor, Jonathan D; Rizvi, Syed M; Conte, Mary M
A perceptual space is a mental workspace of points in a sensory domain that supports similarity and difference judgments and enables further processing such as classification and naming. Perceptual spaces are present across sensory modalities; examples include colors, faces, auditory textures, and odors. Color is perhaps the best-studied perceptual space, but it is atypical in two respects. First, the dimensions of color space are directly linked to the three cone absorption spectra, but the dimensions of generic perceptual spaces are not as readily traceable to single-neuron properties. Second, generic perceptual spaces have more than three dimensions. This is important because representing each distinguishable point in a high-dimensional space by a separate neuron or population is unwieldy; combinatorial strategies may be needed to overcome this hurdle. To study the representation of a complex perceptual space, we focused on a well-characterized 10-dimensional domain of visual textures. Within this domain, we determine perceptual distances in a threshold task (segmentation) and a suprathreshold task (border salience comparison). In N=4 human observers, we find both quantitative and qualitative differences between these sets of measurements. Quantitatively, observers' segmentation thresholds were inconsistent with their uncertainty determined from border salience comparisons. Qualitatively, segmentation thresholds suggested that distances are determined by a coordinate representation with Euclidean geometry. Border salience comparisons, in contrast, indicated a global curvature of the space, and that distances are determined by activity patterns across broadly tuned elements. Thus, our results indicate two representations of this perceptual space, and suggest that they use differing combinatorial strategies. To move from sensory signals to decisions and actions, the brain carries out a sequence of transformations. An important stage in this process is the
Acker, B E; Pastore, R E
In the present study, an accuracy, rather than a reaction time, version of the Garner paradigm was used to evaluate the integrality or separability of major chord components. Tuned (prototype, or P) and mistuned (nonprototype, or NP) sets of root position C-major triads were constructed by holding the C constant in all stimuli and varying the E and G frequencies in 2- and 4-Hz steps. The P stimuli represent small systematic mistunings in the E and G notes relative to an equal-tempered C-major chord. The NP stimuli represent an equivalent range of frequency variation, but relative to a significantly out-of-tune C-major triad. In different experimental sessions, a same-different (AX) task was used to separately evaluate discrimination performance for the E and G frequencies as a function of whether the nontarget frequency (G or E) was fixed or varied in either a correlated or an orthogonal fashion (with the C frequency always held constant). Compared with a fixed baseline condition where only the target frequency changed, both chord components exhibited a significant redundancy gain in the correlated conditions and, to varying degrees, significant interference effects in the orthogonal condition, indicating that the chord components function largely in an integral fashion. Relative to the discrimination of G, discrimination of the E frequency was less influenced by variation in the nontarget (G) frequency, showing that attention, to some degree, could be selectively allocated to the E chord component. In addition, the results were consistent with previous findings that the functional prototype for the major chord category seems to act as a perceptual anchor, rather than as a magnet, and appears to be located in the physiologically defined area of just temperament, as opposed to the more experientially defined area of equal temperament.
Shiman, Leon G.
Confronted with an object of perception, an individual will spontaneously try to identify unambiguously and consistently all its parts; except in rare instances of “illusory phenomena,” he will immediately succeed. This elementary fact is formalized in a law of visual perception. It is used to define sets of stable states for a sensory mode of a biological system. As characterized, stable states are to perception as quantum states are to atomic structure: they represent natural states of physical systems. They are shown to be observable and to have an exact mathematical representation. A class of bounded open subsets of a two-dimensional Euclidean space, whose boundaries are piecewise compact analytic arcs, is used to construct a nontrivial mathematical model for stable states. The finitely many components of this mathematical model of a stable state (image) are mapped onto an object of perception (icon) by perceptual judgments. These judgments, which include the judgment of stability, have an exact interpretation in this model. They unify and make precise such traditional notions of psychology as “Gestalt,” “figureground,” and “(visual) boundary.” Postulates for a general theory of perception are given. They are used to establish a formal relationship between biological and subjective studies of sensory phenomena and so provide a framework in which subjective studies can be used to analyze (their associated) biological processes. In applying these methods to cases, all icons are divided into two classes (the static and dynamic cases). The static case is treated. PMID:273930
Kim, Yong-Hwan; Kang, Dong-Wha; Kim, Dongho; Kim, Hye-Jin; Sasaki, Yuka; Watanabe, Takeo
Visual perceptual learning (VPL) is defined as long-term improvement in performance on a visual-perception task after visual experiences or training. Early studies have found that VPL is highly specific for the trained feature and location, suggesting that VPL is associated with changes in the early visual cortex. However, the generality of visual skills enhancement attributable to action video-game experience suggests that VPL can result from improvement in higher cognitive skills. If so, experience in real-time strategy (RTS) video-game play, which may heavily involve cognitive skills, may also facilitate VPL. To test this hypothesis, we compared VPL between RTS video-game players (VGPs) and non-VGPs (NVGPs) and elucidated underlying structural and functional neural mechanisms. Healthy young human subjects underwent six training sessions on a texture discrimination task. Diffusion-tensor and functional magnetic resonance imaging were performed before and after training. VGPs performed better than NVGPs in the early phase of training. White-matter connectivity between the right external capsule and visual cortex and neuronal activity in the right inferior frontal gyrus (IFG) and anterior cingulate cortex (ACC) were greater in VGPs than NVGPs and were significantly correlated with RTS video-game experience. In both VGPs and NVGPs, there was task-related neuronal activity in the right IFG, ACC, and striatum, which was strengthened after training. These results indicate that RTS video-game experience, associated with changes in higher-order cognitive functions and connectivity between visual and cognitive areas, facilitates VPL in early phases of training. The results support the hypothesis that VPL can occur without involvement of only visual areas. Significance statement: Although early studies found that visual perceptual learning (VPL) is associated with involvement of the visual cortex, generality of visual skills enhancement by action video-game experience
Rooney, Deborah M; Brissman, Inga C; Gauger, Paul G
In continued efforts to maintain standards required for high-stakes examination administration, Society of American Gastrointestinal and Endoscopic Surgeons' Fundamentals of Laparoscopic Surgery (FLS) program requires all prospective test proctors to complete the New FLS Proctor Workshop. As the FLS proctor pool and training evolves, the influence of experience on performance is not clear. In the previous work, we proposed that asynchronous web-based performances might be used to train proctors. In this study, we assessed the accuracy of proctors' ratings from asynchronous web-based performances by comparing the sensitivity and the specificity of ratings from proctors having varied experience levels. A sample of 42 (26% of all registered proctors) FLS proctors (recently trained novice, n = 15; intermediate, n = 20; and expert, n = 7) viewed 2 videotaped, laparoscopic-view FLS performances via the web. The first performance (error) contained 1 predetermined critical performance error in each of the 5 tasks (5 total errors), whereas the second performance (no error) contained no critical errors. For both the performances, participants noted time to complete each of the 5 tasks and any critical errors they observed (dichotomously scored). Participants also completed a demographic section that captured years of experience as a proctor. Using the Kruskal-Wallis test, we compared new trainee, intermediate, and expert proctors' recorded task times for both the performances. The sensitivity and the specificity values were also independently calculated using ratings from the error and the no error performances and then compared using the same test. There were no differences in recorded times across proctor groups for any of the tasks; p = 0.21 and 0.94. Rating sensitivity was 79% (novice), 75% (intermediate), and 83% (expert), with no significant differences across experience levels; p > 0.46. Following removal of the peg transfer task that had particularly low sensitivity
Full Text Available Patients with age-related macular degeneration (AMD or hereditary macular dystrophies (JMD rely on an efficient use of their peripheral visual field. We trained eight AMD and five JMD patients to perform a texture-discrimination task (TDT at their preferred retinal locus (PRL used for fixation. Six training sessions of approximately one hour duration were conducted over a period of approximately 3 weeks. Before, during and after training twelve patients and twelve age-matched controls (the data from two controls had to be discarded later took part in three functional magnetic resonance imaging (fMRI sessions to assess training-related changes in the BOLD response in early visual cortex. Patients benefited from the training measurements as indexed by significant decrease (p=.001 in the stimulus onset asynchrony (SOA between the presentation of the texture target on background and the visual mask, and in a significant location specific effect of the PRL with respect to hit rate (p=.014. The following trends were observed: (i Improvement in Vernier acuity for an eccentric line-bisection task; (ii positive correlation between the development of BOLD signals in early visual cortex and initial fixation stability (r=0.531; (iii positive correlation between the increase in task performance and initial fixation stability (r=0.730. The first two trends were non-significant, whereas the third trend was significant at p=.014, Bonferroni corrected. Consequently, our exploratory study suggests that training on the TDT can enhance eccentric vision in patients with central vision loss. This enhancement is accompanied by a modest alteration in the BOLD response in early visual cortex.
Sabesan, Ramkumar; Barbot, Antoine; Yoon, Geunyoung
Highly aberrated keratoconic (KC) eyes do not elicit the expected visual advantage from customized optical corrections. This is attributed to the neural insensitivity arising from chronic visual experience with poor retinal image quality, dominated by low spatial frequencies. The goal of this study was to investigate if targeted perceptual learning with adaptive optics (AO) can stimulate neural plasticity in these highly aberrated eyes. The worse eye of 2 KC subjects was trained in a contrast threshold test under AO correction. Prior to training, tumbling 'E' visual acuity and contrast sensitivity at 4, 8, 12, 16, 20, 24 and 28 c/deg were measured in both the trained and untrained eyes of each subject with their routine prescription and with AO correction for a 6mm pupil. The high spatial frequency requiring 50% contrast for detection with AO correction was picked as the training frequency. Subjects were required to train on a contrast detection test with AO correction for 1h for 5 consecutive days. During each training session, threshold contrast measurement at the training frequency with AO was conducted. Pre-training measures were repeated after the 5 training sessions in both eyes (i.e., post-training). After training, contrast sensitivity under AO correction improved on average across spatial frequency by a factor of 1.91 (range: 1.77-2.04) and 1.75 (1.22-2.34) for the two subjects. This improvement in contrast sensitivity transferred to visual acuity with the two subjects improving by 1.5 and 1.3 lines respectively with AO following training. One of the two subjects denoted an interocular transfer of training and an improvement in performance with their routine prescription post-training. This training-induced visual benefit demonstrates the potential of AO as a tool for neural rehabilitation in patients with abnormal corneas. Moreover, it reveals a sufficient degree of neural plasticity in normally developed adults who have a long history of abnormal visual
Brooks, Anthony Lewis; Petersson, Eva
This pilot study investigated gesture-based control of video games to promote and motivate self-driven home-based aerobic exercise (AE) training regimes to improve pain threshold associated to fibromyalgia. 10 patients were randomized to 10 sessions each led by a non-medical ‘game-savvy’ Ph...
Xu, Jingping P; He, Zijiang J; Ooi, Teng Leng
Perceptual learning is an important means for the brain to maintain its agility in a dynamic environment. Top-down focal attention, which selects task-relevant stimuli against competing ones in the background, is known to control and select what is learned in adults. Still unknown, is whether the adult brain is able to learn highly visible information beyond the focus of top-down attention. If it is, we should be able to reveal a purely stimulus-driven perceptual learning occurring in functions that are largely determined by the early cortical level, where top-down attention modulation is weak. Such an automatic, stimulus-driven learning mechanism is commonly assumed to operate only in the juvenile brain. We performed perceptual training to reduce sensory eye dominance (SED), a function that taps on the eye-of-origin information represented in the early visual cortex. Two retinal locations were simultaneously stimulated with suprathreshold, dichoptic orthogonal gratings. At each location, monocular cueing triggered perception of the grating images of the weak eye and suppression of the strong eye. Observers attended only to one location and performed orientation discrimination of the gratings seen by the weak eye, while ignoring the highly visible gratings at the second, unattended, location. We found SED was not only reduced at the attended location, but also at the unattended location. Furthermore, other untrained visual functions mediated by higher cortical levels improved. An automatic, stimulus-driven learning mechanism causes synaptic alterations in the early cortical level, with a far-reaching impact on the later cortical levels. Copyright © 2011 Elsevier Ltd. All rights reserved.
between the educational qualifications, computer training and improved professional library activities of the subject (R ... information satisfaction is a subjective or perceptual measure of System. Success and that System usage can be .... The research instruments used for the study was self- developed questionnaire by the ...
Cesare V Parise
Full Text Available Sensory information about the state of the world is generally ambiguous. Understanding how the nervous system resolves such ambiguities to infer the actual state of the world is a central quest for sensory neuroscience. However, the computational principles of perceptual disambiguation are still poorly understood: What drives perceptual decision-making between multiple equally valid solutions? Here we investigate how humans gather and combine sensory information-within and across modalities-to disambiguate motion perception in an ambiguous audiovisual display, where two moving stimuli could appear as either streaming through, or bouncing off each other. By combining psychophysical classification tasks with reverse correlation analyses, we identified the particular spatiotemporal stimulus patterns that elicit a stream or a bounce percept, respectively. From that, we developed and tested a computational model for uni- and multi-sensory perceptual disambiguation that tightly replicates human performance. Specifically, disambiguation relies on knowledge of prototypical bouncing events that contain characteristic patterns of motion energy in the dynamic visual display. Next, the visual information is linearly integrated with auditory cues and prior knowledge about the history of recent perceptual interpretations. What is more, we demonstrate that perceptual decision-making with ambiguous displays is systematically driven by noise, whose random patterns not only promote alternation, but also provide signal-like information that biases perception in highly predictable fashion.
Gramuglia, Andréa Cristina Joia; Tavares, Elaine L M; Rodrigues, Sérgio Augusto; Martins, Regina H G
Vocal nodules constitute the major cause of dysphonia during childhood. Auditory-perceptual and acoustic vocal analyses have been used to differentiate vocal nodules from normal voice in children. To study the value of auditory-perceptual and acoustic vocal analyses in assessments of children with nodules. Diagnostic test study. A comparative study was carried out including 100 children with videolaryngoscopic diagnosis of vocal nodules (nodule group-NG); and 100 children without vocal symptoms and with normal videolaryngoscopic exams (control group-CG). The age range of both groups was between 4 and 11 years. All children underwent auditory-perceptual vocal analyses (GRBASI scale); maximum phonation time and s/z ratio were calculated, and acoustic vocal analysis (MDVP software) were carried out. There was no difference in the values of maximum phonation time and s/z ratio between groups. Auditory-perceptual analysis indicated greater compromising of voice parameters for NG, compared to CG: G (79 versus 24), R (53 versus 3), B (67 versus 23) and S (35 versus 1). The values of acoustic parameters jitter, PPQ, shimmer, APQ, NHR and SPI were higher for NG for CG. The parameter f0 did not differ between groups. Compromising of auditory-perceptual (G, R, B and S) and acoustic vocal parameters (jitter, PPQ, shimmer, APQ, NHR and SPI) was greater for children with nodules than for those of the control group, which makes them important methods for assessing child dysphonia. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
Michiel van Elk
Full Text Available Previous studies have shown that one's prior beliefs have a strong effect on perceptual decision-making and attentional processing. The present study extends these findings by investigating how individual differences in paranormal and conspiracy beliefs are related to perceptual and attentional biases. Two field studies were conducted in which visitors of a paranormal conducted a perceptual decision making task (i.e. the face/house categorization task; Experiment 1 or a visual attention task (i.e. the global/local processing task; Experiment 2. In the first experiment it was found that skeptics compared to believers more often incorrectly categorized ambiguous face stimuli as representing a house, indicating that disbelief rather than belief in the paranormal is driving the bias observed for the categorization of ambiguous stimuli. In the second experiment, it was found that skeptics showed a classical 'global-to-local' interference effect, whereas believers in conspiracy theories were characterized by a stronger 'local-to-global interference effect'. The present study shows that individual differences in paranormal and conspiracy beliefs are associated with perceptual and attentional biases, thereby extending the growing body of work in this field indicating effects of cultural learning on basic perceptual processes.
Roseli Saraiva Moreira Bittar
Full Text Available INTRODUCTION: Persistent postural-perceptual dizziness is the dizziness that lasts for over three months with no clinical explanation for its persistence. The patient's motor response pattern presents changes and most patients manifest significant anxiety. OBJECTIVE: To evaluate the clinical characteristics of patients with persistent postural and perceptual dizziness. METHODS: statistical analysis of clinical aspects of patients with persistent postural-perceptual dizziness. RESULTS: 81 patients, average age: 50.06 ± 12.16 years; female/male ratio: 5.7/1; main reasons for dizziness: visual stimuli (74%, body movements (52%, and sleep deprivation (38%. The most prevalent comorbidities were hypercholesterolemia (31%, migraine headaches (26%, carbohydrate metabolism disorders (22% and cervical syndrome (21%. DHI, State-Trait Anxiety Inventory - Trait, Beck Depression Inventory, and Hospital Anxiety and Depression Scale questionnaires were statistically different (p < 0.05 when compared to controls. 68% demonstrated clinical improvement after treatment with serotonin reuptake inhibitors. CONCLUSION: Persistent postural-perceptual dizziness affects more women than men, with a high associated prevalence of metabolic disorders and migraine. Questionnaires help to identify the predisposition to persistent postural-perceptual dizziness. The prognosis is good with adequate treatment.
de Lange, Floris P; Rahnev, Dobromir A; Donner, Tobias H; Lau, Hakwan
When perceptual decisions are coupled to a specific effector, preparatory motor cortical activity may provide a window into the dynamics of the perceptual choice. Specifically, previous studies have observed a buildup of choice-selective activity in motor regions over time reflecting the integrated sensory evidence provided by visual cortex. Here we ask how this choice-selective motor activity is modified by prior expectation during a visual motion discrimination task. Computational models of decision making formalize decisions as the accumulation of evidence from a starting point to a decision bound. Within this framework, expectation could change the starting point, rate of accumulation, or the decision bound. Using magneto-encephalography in human observers, we specifically tested for changes in the starting point in choice-selective oscillatory activity over motor cortex. Inducing prior expectation about motion direction biased subjects' perceptual judgments as well as the choice-selective motor activity in the 8-30 Hz frequency range before stimulus onset; the individual strength of these behavioral and neural biases were correlated across subjects. In the absence of explicit expectation cues, spontaneous biases in choice-selective activity were evident over motor cortex. These also predicted eventual perceptual choice and were, at least in part, induced by the choice on the previous trial. We conclude that both endogenous and explicitly induced perceptual expectations bias the starting point of decision-related activity, before the accumulation of sensory evidence.
Mukerjee, Amitabha; Sarkar, Mausoom
Hand-engineered definitions of spatial categories are increasingly seen as brittle and spatial concepts in human interactions may need to learn these in terms of perceptually grounded "image schemas". Here, we present a developmental approach for the acquisition of grounded spatial schemas in a perceptual agent. We assume a capability for dynamic visual attention, and perceptual notions of wholeness and proximity. We first learn perceptual-object to linguisticname mappings from simple 2D multi-agent visual streams co-occurring with word-separated utterances. Mutual information based statistical measures are seen to be sufficient to identify nominal participants in a simple discourse, based on a synthetic model of dynamic visual attention. Next, we use this knowledge of nominals to ground the semantics of spatial relations in language.We show that a notion of proximity between perceptual objects is sufficient to obtain a pre-verbal notion of graded spatial poses. Once linguistic data is superimposed on this, simple associative structures lead to distinctions such as "in" or "out". Finally we also show how this can lead to a model of actions, where verbs are learned along with the associated argument structures.
Lincoln, Amy E; Long, Debra L; Swick, Diane; Larsen, Jary; Baynes, Kathleen
The representation of words in sentences can involve the activation and integration of perceptual information. For example, readers who are asked to view pictures of objects relating to a word in a sentence are influenced by perceptual information in the sentence context-readers are faster to respond to a picture of a whole apple after reading, "There is an apple in the bag," than after reading, "There is an apple in the salad." The purpose of this study was to examine how the two cerebral hemispheres use perceptual information about words as a function of sentence context. Patients who had damage to the left or right hemisphere and age-matched control participants read sentences that described, but did not entail, the shape or state of an object. They then made recognition judgments to pictures that either matched or mismatched the perceptual form implied by the sentence. Responses and latencies were examined for a match effect -- faster and more accurate responses to pictures in the match than mismatch condition -- controlling for comprehension ability and lesion size. When comprehension ability and lesion size are properly controlled, left-hemisphere-damaged patients and control participants exhibited the expected match effect, whereas right-hemisphere-damaged participants showed no effect of match condition. These results are consistent with research implicating the right hemisphere in the representation of contextually relevant perceptual information.
Full Text Available Abstract Background Implementing good-quality health and social care requires empowerment of staff members within organizations delivering care. Video Interaction Guidance (VIG is an intervention using positive video feedback to empower staff through reflection on practice. This qualitative study explored the implementation of VIG within an autism care organization in England, from the perspective of staff members undergoing training to deliver VIG. Methods Semi-structured interviews were conducted with a purposive sample of 7 participants working within the organization (5 staff undergoing training to deliver VIG; 2 senior managers influencing co-ordination of training. Participants were asked about their views of VIG and its implementation. The topic guide was informed by Normalization Process Theory (NPT. Data were analysed inductively and emerging issues were related to NPT. Results Five broad themes were identified: (1 participants reported that they and other staff did not understand VIG until they became involved, initially believing it would highlight negative rather than positive practice; (2 enthusiastic feedback from staff who had been involved seemed to encourage other staff to become involved; (3 key implementation challenges included demands of daily work and securing managers’ support; (4 ideas for future practice arising from empowerment through VIG seemed difficult to realise within an organizational culture reportedly unreceptive to creative ideas from staff; (5 individuals’ emotional responses to implementation seemed beyond the reach of NPT, which focused more upon collective processes. Conclusions Implementation of VIG may require recognition that it is not a ‘quick fix’. Peer advocacy may be a fruitful implementation strategy. Senior managers may need to experience VIG to develop their understanding so that they can provide appropriate implementation support. NPT may lack specificity to explain how individual agency
Liston, Dorion B.; Stone, Leland S.
The time that elapses between stimulus onset and the onset of a saccadic eye movement is longer and more variable than can be explained by neural transmission times and synaptic delays (Carpenter, 1981, in: Eye Movements: Cognition & Visual Perception, Earlbaum). In theory, noise underlying response-time (RT) variability could arise at any point along the sensorimotor cascade, from sensory noise arising Vvithin the early visual processing shared Vvith perception to noise in the motor criterion or commands necessary to trigger movements. These two loci for internal noise can be distinguished empirically; sensory internal noise predicts that response time Vvill correlate Vvith perceived stimulus magnitude whereas motor internal noise predicts no such correlation. Methods. We used the data described by Liston and Stone (2008, JNS 28:13866-13875), in which subjects performed a 2AFC saccadic brightness discrimination task and the perceived brightness of the chosen stimulus was then quantified in a second 21FC perceptual task. Results. We binned each subject's data into quartiles for both signal strength (from dimmest to brightest) and RT (from slowest to fastest) and analyzed the trends in perceived brightness. We found significant effects of both signal strength (as expected) and RT on normalized perceived brightness (both p less than 0.0001, 2-way ANOVA), without significant interaction (p = 0.95, 2-way ANOVA). A plot of normalized perceived brightness versus normalized RT show's that more than half of the variance was shared (r2 = 0.56, P less than 0.0001). To rule out any possibility that some signal-strength related artifact was generating this effect, we ran a control analysis on pairs of trials with repeated presentations of identical stimuli and found that stimuli are perceived to be brighter on trials with faster saccades (p less than 0.001, paired t-test across subjects). Conclusion. These data show that shared early visual internal noise jitters perceived
Full Text Available The middle temporal area of the extrastriate visual cortex (area MT is integral to motion perception and is thought to play a key role in the perceptual learning of motion tasks. We have previously found, however, that perceptual learning of a motion discrimination task is possible even when the training stimulus contains locally balanced, motion opponent signals that putatively suppress the response of MT. Assuming at least partial suppression of MT, possible explanations for this learning are that 1 training made MT more responsive by reducing motion opponency, 2 MT remained suppressed and alternative visual areas such as V1 enabled learning and/or 3 suppression of MT increased with training, possibly to reduce noise. Here we used fMRI to test these possibilities. We first confirmed that the motion opponent stimulus did indeed suppress the BOLD response within hMT+ compared to an almost identical stimulus without locally balanced motion signals. We then trained participants on motion opponent or non-opponent stimuli. Training with the motion opponent stimulus reduced the BOLD response within hMT+ and greater reductions in BOLD response were correlated with greater amounts of learning. The opposite relationship between BOLD and behaviour was found at V1 for the group trained on the motion-opponent stimulus and at both V1 and hMT+ for the group trained on the non-opponent motion stimulus. As the average response of many cells within MT to motion opponent stimuli is the same as their response to non-directional flickering noise, the reduced activation of hMT+ after training may reflect noise reduction.
Hoffmann, G; Schmidt, M; Ammon, C
In this study, a video-based infrared camera (IRC) was investigated as a tool to monitor the body temperature of calves. Body surface temperatures were measured contactless using videos from an IRC fixed at a certain location in the calf feeder. The body surface temperatures were analysed retrospectively at three larger areas: the head area (in front of the forehead), the body area (behind forehead) and the area of the entire animal. The rectal temperature served as a reference temperature and was measured with a digital thermometer at the corresponding time point. A total of nine calves (Holstein-Friesians, 8 to 35 weeks old) were examined. The average maximum temperatures of the area of the entire animal (mean±SD: 37.66±0.90°C) and the head area (37.64±0.86°C) were always higher than that of the body area (36.75±1.06°C). The temperatures of the head area and of the entire animal were very similar. However, the maximum temperatures as measured using IRC increased with an increase in calf rectal temperature. The maximum temperatures of each video picture for the entire visible body area of the calves appeared to be sufficient to measure the superficial body temperature. The advantage of the video-based IRC over conventional IR single-picture cameras is that more than one picture per animal can be analysed in a short period of time. This technique provides more data for analysis. Thus, this system shows potential as an indicator for continuous temperature measurements in calves.
Curtis, Henry A; Trang, Karen; Chason, Kevin W; Biddinger, Paul D
Introduction Great demands have been placed on disaster medicine educators. There is a need to develop innovative methods to educate Emergency Physicians in the ever-expanding body of disaster medicine knowledge. The authors sought to demonstrate that video-based learning (VBL) could be a promising alternative to traditional learning methods for teaching disaster medicine core competencies. Hypothesis/Problem The objective was to compare VBL to traditional lecture (TL) for instructing Emergency Medicine residents in the American College of Emergency Physicians (ACEP; Irving, Texas USA) disaster medicine core competencies of patient triage and decontamination. A randomized, controlled pilot study compared two methods of instruction for mass triage, decontamination, and personal protective equipment (PPE). Emergency Medicine resident learning was measured with a knowledge quiz, a Likert scale measuring comfort, and a practical exercise. An independent samples t-test compared the scoring of the VBL with the TL group. Twenty-six residents were randomized to VBL (n=13) or TL (n=13). Knowledge score improvement following video (14.9%) versus lecture (14.1%) did not differ significantly between the groups (P=.74). Comfort score improvement also did not differ (P=.64) between video (18.3%) and lecture groups (15.8%). In the practical skills assessment, the VBL group outperformed the TL group overall (70.4% vs 55.5%; PMedicine residents in the ACEP disaster medicine core competencies of patient triage and decontamination. Curtis HA , Trang K , Chason KW , Biddinger PD . Video-based learning vs traditional lecture for instructing emergency medicine residents in disaster medicine principles of mass triage, decontamination, and personal protective equipment.
Cardoso-Junior, M M; Scarpel, R A
The main focus of risk management is technical and rational analysis about the operational risks and by those imposed by the occupational environment. In this work one seeks to contribute to the risk perception study and to better comprehend how a group of occupational safety students assesses a set of activities and environmental agents. In this way it was used theory sustained by psychometric paradigm and multivariate analysis tools, mainly multidimensional scaling, generalized Procrustes analysis and facets theory, in order to construct the perceptual map of occupational risks. The results obtained showed that the essential characteristics of risks, which were initially splited in 4 facets were detected and maintained in the perceptual map. It was not possible to reveal the cognitive structure of the group, because the variability of the students was too high. Differences among the risks analyzed could not be detected as well in the perceptual map of the group.
van der Helm, Peter A
What is the degree to which knowledge influences visual perceptual processes? This question, which is central to the seeing-versus-thinking debate in cognitive science, is often discussed using examples claimed to be proof of one stance or another. It has, however, also been muddled by the usage of different and unclear definitions of perception. Here, for the well-defined process of perceptual organization, I argue that including speed (or efficiency) into the equation opens a new perspective on the limits of top-down influences of thinking on seeing. While the input of the perceptual organization process may be modifiable and its output enrichable, the process itself seems so fast (or efficient) that thinking hardly has time to intrude and is effective mostly after the fact.
Jabar, Syaheed B; Anderson, Britt
Probability is known to affect perceptual estimations, but an understanding of mechanisms is lacking. Moving beyond binary classification tasks, we had naive participants report the orientation of briefly viewed gratings where we systematically manipulated contingent probability. Participants rapidly developed faster and more precise estimations for high-probability tilts. The shapes of their error distributions, as indexed by a kurtosis measure, also showed a distortion from Gaussian. This kurtosis metric was robust, capturing probability effects that were graded, contextual, and varying as a function of stimulus orientation. Our data can be understood as a probability-induced reduction in the variability or "shape" of estimation errors, as would be expected if probability affects the perceptual representations. As probability manipulations are an implicit component of many endogenous cuing paradigms, changes at the perceptual level could account for changes in performance that might have traditionally been ascribed to "attention." (c) 2015 APA, all rights reserved).
Sohoglu, Ediz; Davis, Matthew H
Human perception is shaped by past experience on multiple timescales. Sudden and dramatic changes in perception occur when prior knowledge or expectations match stimulus content. These immediate effects contrast with the longer-term, more gradual improvements that are characteristic of perceptual learning. Despite extensive investigation of these two experience-dependent phenomena, there is considerable debate about whether they result from common or dissociable neural mechanisms. Here we test single- and dual-mechanism accounts of experience-dependent changes in perception using concurrent magnetoencephalographic and EEG recordings of neural responses evoked by degraded speech. When speech clarity was enhanced by prior knowledge obtained from matching text, we observed reduced neural activity in a peri-auditory region of the superior temporal gyrus (STG). Critically, longer-term improvements in the accuracy of speech recognition following perceptual learning resulted in reduced activity in a nearly identical STG region. Moreover, short-term neural changes caused by prior knowledge and longer-term neural changes arising from perceptual learning were correlated across subjects with the magnitude of learning-induced changes in recognition accuracy. These experience-dependent effects on neural processing could be dissociated from the neural effect of hearing physically clearer speech, which similarly enhanced perception but increased rather than decreased STG responses. Hence, the observed neural effects of prior knowledge and perceptual learning cannot be attributed to epiphenomenal changes in listening effort that accompany enhanced perception. Instead, our results support a predictive coding account of speech perception; computational simulations show how a single mechanism, minimization of prediction error, can drive immediate perceptual effects of prior knowledge and longer-term perceptual learning of degraded speech.
Michael J. Duncan
Full Text Available This study compared the physiological, perceptual and mechanical responses to kettlebell swings at different loads and swing speeds. Following familiarization 16 strength trained participants (10 males, six females, mean age ± SD = 23 ± 2.9 performed four trials: 2 min kettlebell swings with an 8 kg kettlebell at a fast cadence; 2 min kettlebell swings with an 8 kg kettlebell at a slow cadence; 4 min kettlebell swings with a 4 kg kettlebell at a fast cadence; 4 min kettlebell swings with a 4 kg kettlebell at a slow cadence. Repeated measured analysis of variance indicated no significant differences in peak blood lactate or peak net vertical force across loads and cadences (P > 0.05. Significant main effect for time for heart rate indicated that heart rate was higher at the end of each bout than at mid-point (P = 0.001. A significant Load X cadence interaction for rating of perceived exertion (RPE (P = 0.030 revealed that RPE values were significantly higher in the 8 kg slow cadence condition compared to the 4 kg slow (P = 0.002 and 4 kg fast (P = 0.016 conditions. In summary, this study indicates that the physiological and mechanical responses to kettlebell swings at 4 kg and 8 kg loads and at fast and slow cadence were similar, whereas the perceptual response is greater when swinging an 8 kg kettlebell at slow cadence.
Killian, Nathaniel J; Vurro, Milena; Keith, Sarah B; Kyada, Margee J; Pezaris, John S
Visual perceptual grouping, the process of forming global percepts from discrete elements, is experience-dependent. Here we show that the learning time course in an animal model of artificial vision is predicted primarily from the density of visual elements. Three naïve adult non-human primates were tasked with recognizing the letters of the Roman alphabet presented at variable size and visualized through patterns of discrete visual elements, specifically, simulated phosphenes mimicking a thalamic visual prosthesis. The animals viewed a spatially static letter using a gaze-contingent pattern and then chose, by gaze fixation, between a matching letter and a non-matching distractor. Months of learning were required for the animals to recognize letters using simulated phosphene vision. Learning rates increased in proportion to the mean density of the phosphenes in each pattern. Furthermore, skill acquisition transferred from trained to untrained patterns, not depending on the precise retinal layout of the simulated phosphenes. Taken together, the findings suggest that learning of perceptual grouping in a gaze-contingent visual prosthesis can be described simply by the density of visual activation.
Mednick, Sara C; Cai, Denise J; Kanady, Jennifer; Drummond, Sean P A
Caffeine, the world's most common psychoactive substance, is used by approximately 90% of North Americans everyday. Little is known, however, about its benefits for memory. Napping has been shown to increase alertness and promote learning on some memory tasks. We directly compared caffeine (200mg) with napping (60-90min) and placebo on three distinct memory processes: declarative verbal memory, procedural motor skills, and perceptual learning. In the verbal task, recall and recognition for unassociated words were tested after a 7h retention period (with a between-session nap or drug intervention). A second, different, word list was administered post-intervention and memory was tested after a 20min retention period. The non-declarative tasks (finger tapping task (FTT) and texture discrimination task (TDT)) were trained before the intervention and then retested afterwards. Naps enhanced recall of words after a 7h and 20min retention interval relative to both caffeine and placebo. Caffeine significantly impaired motor learning compared to placebo and naps. Napping produced robust perceptual learning compared with placebo; however, naps and caffeine were not significantly different. These findings provide evidence of the limited benefits of caffeine for memory improvement compared with napping. We hypothesize that impairment from caffeine may be restricted to tasks that contain explicit information; whereas strictly implicit learning is less compromised.
Hartmann, Martin; Lartillot, Olivier; Toiviainen, Petri
The perceptual structure of music is a fundamental issue in music psychology that can be systematically addressed via computational models. This study estimated the contribution of spectral, rhythmic and tonal descriptors for prediction of perceptual segmentation across stimuli. In a real-time task......-linear fuzzy integration of basic and interaction descriptors of local musical novelty. We found that musicianship of listeners and segmentation task had an effect on model prediction rate, dimensionality and components. Changes in tonality and rhythm, as well as simultaneous change of these aspects were...... dependency. The role of interactions on perception of musical change has an impact on the study of neural, kinetic and speech stream processing....
Hjortkjær, Jens; Walther-Hansen, Mads
compression. Surprisingly, the results failed to reveal any evidence of the effects of dynamic range compression on subjective preference or perceived depth cues. Perceptual data suggest that listeners are less sensitive than commonly believed to even high levels of compression. As measured in terms...... of differences in the peak-to-average ratio, compression has little perceptual effect other than increased loudness or clipping effects that only occur at high levels of compression. One explanation for the inconsistency between data and belief might result from the fact that compression is frequently...
Volk, Christer Peter; Lavandier, Mathieu; Bech, Søren
The perceptual differences between the sound reproductions of headphones were investigated in a pair-wise comparison study. Two musical excerpts were reproduced over 21 headphones positioned on a mannequin and recorded. The recordings were then processed and reproduced over one set of headphones....... A multidimensional scaling analysis revealed two dominating perceptual dimensions used by the listeners to differentiate the reproductions of the headphones. These dimensions were similar for the two musical excerpts. Objective metrics are proposed to describe them, leading to correlations ranging from 0.89 to 0...
Wan, Yi-Ting; Chiang, Ching-Sui; Chen, Sharon Chia-Ju; Wang, Chih-Chung; Wuang, Yee-Pay
The primary purpose of this study was to investigate the visual perceptual functions measured by the Test of Visual Perceptual Skill-Third Edition (TVPS-3) in Down syndrome (DS). Seventy individuals with DS, seventy with typical development (TD), and forty mental-age-matched participants with intellectual disabilities (ID) were recruited for the assessment session. Significant between-group differences in TVPS-3 were observed between either DS or ID and TD groups. There was no significant difference on TVPS-3 between DS and ID groups. Implications for clinical professionals and recommendations for further research are discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.
Explains for the first time how "computing with words" can aid in making subjective judgments. Lotfi Zadeh, the father of fuzzy logic, coined the phrase "computing with words" (CWW) to describe a methodology in which the objects of computation are words and propositions drawn from a natural language. Perceptual Computing explains how to implement CWW to aid in the important area of making subjective judgments, using a methodology that leads to an interactive device—a "Perceptual Computer"—that propagates random and linguistic uncertainties into the subjective judg
Full Text Available Abstract Background There is increasing focus on patient-centred communicative approaches in medical consultations, but few studies have shown the extent to which patients' positive coping strategies and psychological assets are addressed by general practitioners (GPs on a regular day at the office. This study measures the frequency of GPs' use of questions and comments addressing their patients' coping strategies or resources. Methods Twenty-four GPs were video-recorded in 145 consultations. The consultations were coded using a modified version of the Roter Interaction Analysis System. In this study, we also developed four additional coding categories based on cognitive therapy and solution-focused therapy: attribution, resources, coping, and solution-focused techniques. The reliability between coders was established, a factor analysis was applied to test the relationship between the communication categories, and a tentative validating exercise was performed by reversed coding. Results Cohen's kappa was 0.52 between coders. Only 2% of the utterances could be categorized as resource or coping oriented. Six GPs contributed 59% of these utterances. The factor analysis identified two factors, one task oriented and one patient oriented. Conclusion The frequency of communication about coping and resources was very low. Communication skills training for GPs in this field is required. Further validating studies of this kind of measurement tool are warranted.
Andrew T Astle
Full Text Available Practice helps improve performance on a variety of visual tasks. Previous studies have shown that the magnitude of these improvements is inversely proportional to initial levels of performance, with subjects who perform more poorly at the start tending to improve most during perceptual training. If initial performance levels determine the absolute magnitude of learning, it follows that equating performance at the start of training should lead to equivalent amounts of learning. Here we test this prediction by comparing learning on an abutting Vernier alignment task with stimuli presented at two retinal eccentricities (5 and 15 deg equated in terms of either retinal size (unscaled stimuli or cortical size (scaled stimuli. Prior to learning, unscaled stimuli produced larger alignment thresholds at the more peripheral eccentricity, whereas scaled stimuli produced equivalent alignment thresholds. Consistent with previous work, we found that the magnitude of learning for participants who trained over eight daily sessions with the unscaled stimuli (n=11 was significantly larger at 15 than 5 degrees eccentricity. However, when stimuli were spatially scaled (n=11, we found equivalent amounts of learning at each location. These data suggest differences in the magnitude of learning can be accounted for by differences in the cortical representation of stimuli. Cortical scale may set not only the initial performance level but also the upper limit for the magnitude of performance improvements following training.
Hill-Haas, S V; Coutts, A J; Rowsell, G J; Dawson, B T
The aim of this study was to compare 7 weeks of soccer-specific small-sided game (SSG) and mixed generic fitness training, on selected physiological, perceptual and performance variables. Twenty-five elite youth players were randomly allocated to either a SSG (coach selected) or generic training group (GTG), in a randomised, parallel matched-group design. In addition to normal training, each group completed two fitness training sessions per week of equal duration. Players completed a V O (2 max) treadmill test, Multistage Fitness Test (MSFT), Yo-Yo Intermittent Recovery Test Level 1 (YYIRTL1), 12x20 m test of repeated-sprint ability (RSA) and 20-m sprint test pre and post training. Training heart rate, perceived training intensity and perceptual fatigue measures were recorded throughout the training period. There were no differences in training heart rate or perceptual well-being measures. However, the GTG did perceive their training to be more intense than SSG. There were no changes in either group for V O (2 max), MSFT, RSA or sprint performance. However, there were improvements in YYIRTL1 performance for both groups over time, but not between groups. The results show that both types of training are equally effective at improving pre-season YYIRTL1 performance, despite GTG being perceived to be more intense. Georg Thieme Verlag KG Stuttgart.
Rämö, Jussi; Christensen, Lasse; Bech, Søren
This paper focuses on validating a perceptual distraction model, which aims to predict user’s perceived distraction caused by audio-on-audio interference, e.g., two competing audio sources within the same listening space. Originally, the distraction model was trained with music-on-music stimuli...... that the model performance is equally good in both zones, i.e., with both speech-on-music and music-on-speech stimuli, and comparable to the previous validation round (RMSE approximately 10%). The results further confirm that the distraction model can be used as a valuable tool in evaluating and optimizing...... using a simple loudspeaker setup, consisting of only two loudspeakers, one for the target sound source and the other for the interfering sound source. Recently, the model was successfully validated in a complex personal sound-zone system with speech-on-music stimuli. Second round of validations were...
Seow, Ming-Jung; Asari, Vijayan K
In this paper, we propose the concept of a manifold of color perception through empirical observation that the center-surround properties of images in a perceptually similar environment define a manifold in the high dimensional space. Such a manifold representation can be learned using a novel recurrent neural network based learning algorithm. Unlike the conventional recurrent neural network model in which the memory is stored in an attractive fixed point at discrete locations in the state space, the dynamics of the proposed learning algorithm represent memory as a nonlinear line of attraction. The region of convergence around the nonlinear line is defined by the statistical characteristics of the training data. This learned manifold can then be used as a basis for color correction of the images having different color perception to the learned color perception. Experimental results show that the proposed recurrent neural network learning algorithm is capable of color balance the lighting variations in images captured in different environments successfully.
Rämö, Jussi; Christensen, Lasse; Bech, Søren
This paper focuses on validating a perceptual distraction model, which aims to predict user's perceived distraction caused by audio-on-audio interference. Originally, the distraction model was trained with music targets and interferers using a simple loudspeaker setup, consisting of only two...... loudspeakers. Recently, the model was successfully validated in a complex personal sound-zone system with music targets and speech interferers. In this paper, a second round of validations were conducted by physically altering the sound-zone system and running listening experiments utilizing both of the two...... sound zones within the sound-zone system. Thus, validating the model using a different sound-zone system with both speech-on-music and music-on-speech stimuli sets. The results show that the model performance is equally good in both zones, i.e., with both speech- on-music and music-on-speech stimuli...
Rämö, Jussi; Christensen, Lasse; Bech, Søren
This paper focuses on validating a perceptual distraction model, which aims to predict user’s perceived distraction caused by audio-on-audio interference, e.g., two competing audio sources within the same listening space. Originally, the distraction model was trained with music-on-music stimuli...... using a simple loudspeaker setup, consisting of only two loudspeakers, one for the target sound source and the other for the interfering sound source. Recently, the model was successfully validated in a complex personal sound-zone system with speech-on-music stimuli. Second round of validations were...... conducted by physically altering the sound-zone system and running a set of new listening experiments utilizing two sound zones within the sound-zone system. Thus, validating the model using a different sound-zone system with both speech-on-music and music-on-speech stimuli sets. Preliminary results show...
Ito, J.; Nikolaev, A.R.; Luman, M.; Aukes, M.F.; Nakatani, C.; Leeuwen, C.
According to a widely cited finding by Ellis and Stark (1978 Perception 7 575-581), the duration of eye fixations is longer at the instant of perceptual reversal of an ambiguous figure than before or after the reversal. However, long fixations are more likely to include samples of an independent
Li, Tianhao; Fu, Qian-Jie
Purpose: To determine whether perceptual adaptation improves voice gender discrimination of spectrally shifted vowels and, if so, which acoustic cues contribute to the improvement. Method: Voice gender discrimination was measured for 10 normal-hearing subjects, during 5 days of adaptation to spectrally shifted vowels, produced by processing the…
Korjoukov, I.; Jeurissen, D.; Kloosterman, N.A.; Verhoeven, J.E.; Scholte, H.S.; Roelfsema, P.R.
Visual perception starts with localized filters that subdivide the image into fragments that undergo separate analyses. The visual system has to reconstruct objects by grouping image fragments that belong to the same object. A widely held view is that perceptual grouping occurs in parallel across
Shah, Rahul K; Woodnorth, Geralyn Harvey; Glynn, Amy; Nuss, Roger C
To present the epidemiology and correlation with perceptual analysis of vocal nodules in pediatric patients. Retrospective review of patients seen in a tertiary care pediatric hospital's voice center from 1996 to 2003. Six hundred and forty-six patients were evaluated with videostroboscopic examinations and perceptual analysis of voice characteristics by speech pathologists. Appropriate treatment was based on the pathology identified. Two hundred and fifty-four patients (40%) with an average age of 7.7 years (range 0.1-19.3 years) were identified as having vocal nodules. Of these, 72% were male. Six patients (2%) were under the age of 7 months. Nodules were most commonly found in males, aged 3-10 years old. Evidence of gastro-esophageal reflux disease was found in one-quarter of patients; hyperfunction of the larynx was seen in three-fourths. Hyperfunction of the larynx correlates with the size of vocal nodules. Distortion of the vocal fold mucosal wave was not present. Perceptual analysis revealed positive correlation of the severity of hoarseness, breathiness, straining and aphonia with the size of vocal nodules. The epidemiology and correlation with perceptual voice analysis in pediatric patients with vocal nodules is presented. Hyperfunction of the larynx correlates with nodule size, while the presence of reflux disease does not. The severity of hoarseness, breathiness, straining and aphonia correlates with the size of vocal nodules.
Zylberberg, A.; Roelfsema, Pieter R; Sigman, Mariano
Confidence in a perceptual decision is a judgment about the quality of the sensory evidence. The quality of the evidence depends not only on its strength ('signal') but critically on its reliability ('noise'), but the separate contribution of these quantities to the formation of confidence judgments
Joshi, Suyash Narendra; Jesteadt, Walt
complexes have been shown to produce different outputs at the basilar membrane and different amounts of forward and simultaneous masking. The perceptual weights for loudness did not differ for these two complexes. To determine whether the level rove introduced to obtain weights had changed the fundamental...
Vergeer, M.L.T.; Lier, R.J. van
We show that the flash-induced fading effect can be influenced by grouping based on colour and shape similarity. In flash-induced fading, peripherally presented elements perceptually disappear after a flash has been presented around or next to the element(s) (Kanai and Kamitani, 2003 Journal of
Andrillon, Thomas; Kouider, Sid; Agus, Trevor; Pressnitzer, Daniel
Experience continuously imprints on the brain at all stages of life. The traces it leaves behind can produce perceptual learning , which drives adaptive behavior to previously encountered stimuli. Recently, it has been shown that even random noise, a type of sound devoid of acoustic structure, can trigger fast and robust perceptual learning after repeated exposure . Here, by combining psychophysics, electroencephalography (EEG), and modeling, we show that the perceptual learning of noise is associated with evoked potentials, without any salient physical discontinuity or obvious acoustic landmark in the sound. Rather, the potentials appeared whenever a memory trace was observed behaviorally. Such memory-evoked potentials were characterized by early latencies and auditory topographies, consistent with a sensory origin. Furthermore, they were generated even on conditions of diverted attention. The EEG waveforms could be modeled as standard evoked responses to auditory events (N1-P2) , triggered by idiosyncratic perceptual features acquired through learning. Thus, we argue that the learning of noise is accompanied by the rapid formation of sharp neural selectivity to arbitrary and complex acoustic patterns, within sensory regions. Such a mechanism bridges the gap between the short-term and longer-term plasticity observed in the learning of noise [2, 4-6]. It could also be key to the processing of natural sounds within auditory cortices , suggesting that the neural code for sound source identification will be shaped by experience as well as by acoustics. Copyright © 2015 Elsevier Ltd. All rights reserved.
The Individually Prescribed Instruction (IPI) Model developed by Bolvin and Glaser (1968) is applied to a perceptual development curriculum for children manifesting learning disabilities. The Model utilizes criterion referenced tests for behavioral objectives in four areas: general motor, visual motor, auditory motor, and integrative. Eight units…
The purpose of this individualized perceptual skills curriculum is to ensure that each child acquires facility in processing concrete information before being exposed to abstraction demands of an academic program. The four major curriculum areas described are general motor, visual motor, auditory motor, and integrative. Unit areas are defined,…
Mitchell, Chris; Hall, Geoffrey
We present a review of recent studies of perceptual learning conducted with nonhuman animals. The focus of this research has been to elucidate the mechanisms by which mere exposure to a pair of similar stimuli can increase the ease with which those stimuli are discriminated. These studies establish an important role for 2 mechanisms, one involving inhibitory associations between the unique features of the stimuli, the other involving a long-term habituation process that enhances the relative salience of these features. We then examine recent work investigating equivalent perceptual learning procedures with human participants. Our aim is to determine the extent to which the phenomena exhibited by people are susceptible to explanation in terms of the mechanisms revealed by the animal studies. Although we find no evidence that associative inhibition contributes to the perceptual learning effect in humans, initial detection of unique features (those that allow discrimination between 2 similar stimuli) appears to depend on an habituation process. Once the unique features have been detected, a tendency to attend to those features and to learn about their properties enhances subsequent discrimination. We conclude that the effects obtained with humans engage mechanisms additional to those seen in animals but argue that, for the most part, these have their basis in learning processes that are common to animals and people. In a final section, we discuss some implications of this analysis of perceptual learning for other aspects of experimental psychology and consider some potential applications. (PsycINFO Database Record (c) 2013 APA, all rights reserved).
Bartolucci, Marco; Smith, Andrew T.
Practicing a visual task commonly results in improved performance. Often the improvement does not transfer well to a new retinal location, suggesting that it is mediated by changes occurring in early visual cortex, and indeed neuroimaging and neurophysiological studies both demonstrate that perceptual learning is associated with altered activity…
Bitzer, Sebastian; Bruineberg, Jelle; Kiebel, Stefan J
Even for simple perceptual decisions, the mechanisms that the brain employs are still under debate. Although current consensus states that the brain accumulates evidence extracted from noisy sensory information, open questions remain about how this simple model relates to other perceptual phenomena such as flexibility in decisions, decision-dependent modulation of sensory gain, or confidence about a decision. We propose a novel approach of how perceptual decisions are made by combining two influential formalisms into a new model. Specifically, we embed an attractor model of decision making into a probabilistic framework that models decision making as Bayesian inference. We show that the new model can explain decision making behaviour by fitting it to experimental data. In addition, the new model combines for the first time three important features: First, the model can update decisions in response to switches in the underlying stimulus. Second, the probabilistic formulation accounts for top-down effects that may explain recent experimental findings of decision-related gain modulation of sensory neurons. Finally, the model computes an explicit measure of confidence which we relate to recent experimental evidence for confidence computations in perceptual decision tasks.
Hensley, Wayne E.; Angoli, Marilyn
Both balance and reinforcement theories were used in an examination of the perceptual distortion of height among 146 college debaters. Balance theory predicted that losers would distort winners' heights upward; reinforcement theory predicted that winners would distort losers' heights upward. The results confirmed both predictions. The possibility…
Gratz, Elizabeth W.; Gratz, J. E.
Aims to increase awareness of and sensitivity to perceptual and subliminal communication by focusing on selected applications of them in present day society. The basic theories are (1) communication is used to try to change a person's behavior and (2) it is being used primarily for deception rather than information. (JOW)
Calvo, Manuel G.; Fernandez-Martin, Andres; Nummenmaa, Lauri
Why is a face with a smile but non-happy eyes likely to be interpreted as happy? We used blended expressions in which a smiling mouth was incongruent with the eyes (e.g., angry eyes), as well as genuine expressions with congruent eyes and mouth (e.g., both happy or angry). Tasks involved detection of a smiling mouth (perceptual), categorization of…
Henk, William A.
Behaviorism cannot adequately explain language processing. A synthesis of the psycholinguistic and information processing approaches of cognitive psychology, however, can provide the basis for a speculative analysis of reading, if this synthesis is tempered by a perceptual learning theory of uncertainty reduction. Theorists of information…
Lee, Alice; Gibbon, Fiona E.; O'Donovan, Cliona
Increased tongue-palate contact for perceptually acceptable alveolar stops has been observed in children with speech sound disorders (SSD). This is a retrospective study that further investigated this issue by using quantitative measures to compare the target alveolar stops /t/, /d/ and /n/ produced in words by nine children with SSD (20 tokens of…
Cognitive ability refers to the characteristic approach by the brain in processing information. These can be observed through various aspects of cognition such as intelligence and perceptual ability. Studies have shown that both mental constituents originate from the same neurological substrate in the prefrontal cortex.
Andrew J. Oxenham
Full Text Available Recent physiological studies in several rodent species have revealed that permanent damage can occur to the auditory system after exposure to a noise that produces only a temporary shift in absolute thresholds. The damage has been found to occur in the synapses between the cochlea’s inner hair cells and the auditory nerve, effectively severing part of the connection between the ear and the brain. This synaptopathy has been termed hidden hearing loss because its effects are not thought to be revealed in standard clinical, behavioral, or physiological measures of absolute threshold. It is currently unknown whether humans suffer from similar deficits after noise exposure. Even if synaptopathy occurs in humans, it remains unclear what the perceptual consequences might be or how they should best be measured. Here, we apply a simple theoretical model, taken from signal detection theory, to provide some predictions for what perceptual effects could be expected for a given loss of synapses. Predictions are made for a number of basic perceptual tasks, including tone detection in quiet and in noise, frequency discrimination, level discrimination, and binaural lateralization. The model’s predictions are in line with the empirical observations that a 50% loss of synapses leads to changes in threshold that are too small to be reliably measured. Overall, the model provides a simple initial quantitative framework for understanding and predicting the perceptual effects of synaptopathy in humans.
Library quality is no longer evaluated solely on the value of its collections, as user perceptions of service quality play an increasingly important role in defining overall library value. This paper presents a retooling of the LibQUAL+ survey instrument, blending the gap measurement model with perceptual congruence model studies from information…
Davis, Rebecca A. O.; Bockbrader, Marcia A.; Murphy, Robin R.; Hetrick, William P.; O'Donnell, Brian F.
Case reports and sensory inventories suggest that autism involves sensory processing anomalies. Behavioral tests indicate impaired motion and normal form perception in autism. The present study used first-person accounts to investigate perceptual anomalies and related subjective to psychophysical measures. Nine high-functioning children with…
Rodríguez, Gabriel; Angulo, Rocío
An experiment with human participants established a novel procedure to assess perceptual learning with tactile stimuli. Participants received unsupervised exposure to two sandpaper surfaces differing in roughness (A and B). The ability of the participants to discriminate between the stimuli was subsequently assessed on a same/different test. It…
Poljac, Ervin; de-Wit, Lee; Wagemans, Johan
Humans can rapidly extract object and category information from an image despite surprising limitations in detecting changes to the individual parts of that image. In this article we provide evidence that the construction of a perceptual whole, or Gestalt, reduces awareness of changes to the parts of this object. This result suggests that the…
Scheiter, Katharina; Jarodzka, Halszka
Scheiter, K., & Jarodzka, H. (2011, May). Teaching perceptual skills in clinical diagnostics using digital media. Presentation at the 2nd International Conference “Research in Medical Education”: Shaping diamonds from bench to bedside, Universität Tübingen.
Color image segmentation using perceptual spaces through applets for determining and preventing diseases in chili peppers. JL González-Pérez, MC Espino-Gudiño, J Gudiño-Bazaldúa, JL Rojas-Rentería, V Rodríguez-Hernández, VM Castaño ...
Volk, Christer Peter; Bech, Søren; Pedersen, Torben H.
A literature study was conducted focusing on maximizing objectivity of results from listening evaluations aimed at establishing the relationship between physical and perceptual measurements of loudspeakers. The purpose of the study was to identify and examine factors influencing the objectivity o...
de Jong, Maartje C; Brascamp, Jan W; Kemner, Chantal; van Ee, Raymond; Verstraten, Frans A J
The way we perceive the present visual environment is influenced by past visual experiences. Here we investigated the neural basis of such experience dependency. We repeatedly presented human observers with an ambiguous visual stimulus (structure-from-motion) that can give rise to two distinct perceptual interpretations. Past visual experience is known to influence the perception of such stimuli. We recorded fast dynamics of neural activity shortly after stimulus onset using event-related electroencephalography. The number of previous occurrences of a certain percept modulated early posterior brain activity starting as early as 50 ms after stimulus onset. This modulation developed across hundreds of percept repetitions, reflecting several minutes of accumulating perceptual experience. Importantly, there was no such modulation when the mere number of previous stimulus presentations was considered regardless of how they were perceived. This indicates that the effect depended on previous perception rather than previous visual input. The short latency and posterior scalp location of the effect suggest that perceptual history modified bottom-up stimulus processing in early visual cortex. We propose that bottom-up neural responses to a given visual presentation are shaped, in part, by feedback modulation that occurred during previous presentations, thus allowing these responses to be biased in light of previous perceptual decisions. Copyright © 2014 the authors 0270-6474/14/349970-12$15.00/0.