FOPR test: a virtual reality-based technique to assess field of perception and field of regard in hemispatial neglect.

BACKGROUND: We previously proposed a novel virtual reality-based method to assess human field of perception (FOP) and field of regard (FOR), termed the FOPR test. This study assessed the diagnostic validity of the FOPR test for hemispatial neglect (HSN). METHODS: We included 19 stroke patients with a lesion in the right hemisphere and with HSN (HSN+SS), 22 stroke patients with a lesion in the right hemisphere and without HSN (HSN-SS), and 22 healthy controls aged 19-65 years. The success rate (SR) and response time (RT) in the FOPR test for both FOP and FOR were assessed (FOP-SR, FOR-SR, FOP-RT, and FOR-RT, respectively). Using a Bland-Altman plot, agreements between the FOPR test and conventional tests were confirmed, and the FOPR test accuracy was verified using the support vector machine (SVM). Measured values were analysed using ANOVA and Kruskall-Wallis tests for group comparison. RESULTS: The Bland-Altman plot showed good agreement between FOPR test and conventional tests; individuals within 95% agreement limits were within the range of 94.8-100.0%. The SVM classification accuracy, using FOP and FOR variables from the left hemispace, ranged from 83.3 to 100.0% in a binary classification (HSN vs non-HSN). The FOPR test demonstrated differences in SR and RT for both FOP and FOR across the groups. CONCLUSION: The FOPR test was valid for the HSN diagnosis and provided quantitative and intuitive information regarding visuospatial function. Furthermore, it might enhance our understanding of visuospatial function including HSN by applying the time relative component and concepts of perception and exploration, FOP and FOR. TRIAL REGISTRATION: NCT03463122. Registered 13 March 2018, retrospectively registered.

Development and validation of a computer-based measure of symmetry and arranging behavior in obsessive-compulsive disorder: a preliminary study.

OBJECTIVE: While compulsive ordering and arranging, and a preoccupation with symmetry are common presentations of obsessive-compulsive disorder (OCD), little attention has been given to these types of symptoms in the assessment of patients with OCD. The goal of the present study was to develop and evaluate psychometric properties for the objective and quantitative measurement of compulsive symptoms related to symmetry and arranging. METHODS: Thirty-five normal volunteers performed computer-simulated environment tasks under four different conditions with or without a target and distraction. Primary dependent variables included several indices of time and manipulation of arranging behaviors. We evaluated the validity of the task by comparing the novel behavioral measures with standardized measures such as the Symmetry, Ordering and Arranging Questionnaire (SOAQ), Obsessive Compulsive Inventory-Revised (OCI-R), Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), Barratt Impulsiveness Scale (BIS-11), and Quality of Life Scale (WHOQOL). RESULTS: We found a significant positive correlation between the arrangement time (time to complete the task) with the SOAQ score and the "ordering" subscore of the OCI-R. In addition, the number of manipulations was positively correlated with the SOAQ score and the "ordering" subscore of the OCI-R. There were no significant correlations between behavioral parameters and other scales measuring constructs less relevant to the symptoms of OCD related to ordering/symmetry. There was only a significant main effect of the target on the arrangement time. CONCLUSION: This study demonstrates the good convergent and discriminant validity of this task as a novel behavioral measure for the assessment of arranging compulsion symptoms. We can infer from the results that subjects are likely to spend more time in compulsive arranging when the target for the task is given.

Feasibility of hemispatial neglect rehabilitation with virtual reality-based visual exploration therapy among patients with stroke: randomised controlled trial.

Background: Hemispatial neglect (HSN) was diagnosed using a virtual reality-based test (FOPR test) that explores the field of perception (FOP) and field of regard (FOR). Here, we developed virtual reality-visual exploration therapy (VR-VET) combining elements from the FOPR test and visual exploration therapy (VET) and examined its efficacy for HSN rehabilitation following stroke. Methods: Eleven participants were randomly assigned to different groups, training with VR-VET first then waiting without VR-VET training (TW), or vice versa (WT). The TW group completed 20 sessions of a VR-VET program using a head-mounted display followed by 4 weeks of waiting, while the WT group completed the opposite regimen. Clinical HSN measurements [line bisection test (LBT), star cancellation test (SCT), Catherine Bergego Scale (CBS), CBS perceptual-attentional (CBS-PA), and CBS motor-explanatory (CBS-ME)] and FOPR tests [response time (RT), success rate (SR), and head movement (HM) for both FOP and FOR] were assessed by blinded face-to-face assessments. Results: Five and six participants were allocated to the TW and WT groups, respectively, and no dropout occurred throughout the study. VR-VET considerably improved LBT scores, FOR variables (FOR-RT, FOR-SR), FOP-LEFT variables (FOP-LEFT-RT, FOP-LEFT-SR), and FOR-LEFT variables (FOR-LEFT-RT, FOR-LEFT-SR) compared to waiting without VR-VET. Additionally, VR-VET extensively improved FOP-SR, CBS, and CBS-PA, where waiting failed to make a significant change. The VR-VET made more improvements in the left hemispace than in the right hemispace in FOP-RT, FOP-SR, FOR-RT, and FOR-SR. Conclusion: The observed improvements in clinical assessments and FOPR tests represent the translatability of these improvements to real-world function and the multi-dimensional effects of VR-VET training. Clinical trial registration: https://clinicaltrials.gov/ct2/show/NCT03463122, identifier NCT03463122.

Impact of Personalized Avatars and Motion Synchrony on Embodiment and Users' Subjective Experience: Empirical Study.

BACKGROUND: Embodiment through a virtual avatar is a key element for people to feel that they are in the virtual world. OBJECTIVE: This study aimed to elucidate the interaction between 2 methods of eliciting embodiment through a virtual avatar: motion synchronization and appearance similarity between a human and avatar, to understand embodiment (agency, body ownership, and self-location) and subjective experience (presence, simulator sickness, and emotion) in virtual reality. METHODS: Using a full-body motion capture system, 24 participants experienced their virtual avatars with a 3D-scanned face and size-matched body from a first-person perspective. This study used a 2 (motion; sync and async) × 2 (appearance; personalized and generic) within-subject design. RESULTS: The results indicated that agency and body ownership increased when motion and appearance were matched, whereas self-location, presence, and emotion were affected by motion only. Interestingly, if the avatar's appearance was similar to the participants (personalized avatar), they formed an agency toward the avatar's motion that was not performed by themselves. CONCLUSIONS: Our findings would be applicable in the field of behavioral therapy, rehabilitation, and entertainment applications, by eliciting higher agency with a personalized avatar.

Evaluating attention deficit hyperactivity disorder symptoms in children and adolescents through tracked head movements in a virtual reality classroom: The effect of social cues with different sensory modalities.

Background: Attention deficit hyperactivity disorder (ADHD) is clinically diagnosed; however, quantitative analysis to statistically analyze the symptom severity of children with ADHD via the measurement of head movement is still in progress. Studies focusing on the cues that may influence the attention of children with ADHD in classroom settings, where children spend a considerable amount of time, are relatively scarce. Virtual reality allows real-life simulation of classroom environments and thus provides an opportunity to test a range of theories in a naturalistic and controlled manner. The objective of this study was to investigate the correlation between participants' head movements and their reports of inattention and hyperactivity, and to investigate how their head movements are affected by different social cues of different sensory modalities. Methods: Thirty-seven children and adolescents with (n = 20) and without (n = 17) ADHD were recruited for this study. All participants were assessed for diagnoses, clinical symptoms, and self-reported symptoms. A virtual reality-continuous performance test (VR-CPT) was conducted under four conditions: (1) control, (2) no-cue, (3) visual cue, and (4) visual/audio cue. A quantitativecomparison of the participants' head movements was conducted in three dimensions (pitch [head nods], yaw [head turns], and roll [lateral head inclinations]) using a head-mounted display (HMD) in a VR classroom environment. Task-irrelevant head movements were analyzed separately, considering the dimension of movement needed to perform the VR-CPT. Results: The magnitude of head movement, especially task-irrelevant head movement, significantly correlated with the current standard of clinical assessment in the ADHD group. Regarding the four conditions, head movement showed changes according to the complexity of social cues in both the ADHD and healthy control (HC) groups. Conclusion: Children and adolescents with ADHD showed decreasing task-irrelevant movements in the presence of social stimuli toward the intended orientation. As a proof-of-concept study, this study preliminarily identifies the potential of VR as a tool to understand and investigate the classroom behavior of children with ADHD in a controlled, systematic manner.

Development of a computer-based behavioral assessment of checking behavior in obsessive-compulsive disorder.

OBJECTIVE: The goal of the current study was to develop and obtain preliminary psychometric data for a computer-based behavioral measure of compulsive checking behavior in a sample of patients with obsessive-compulsive disorder (OCD). METHOD: We examined performance on a novel behavioral measure in 30 patients with OCD and 27 matched healthy controls. In the computerized assessment, participants navigated through two virtual environments (home and office) using a joystick and head-mounted display. The experiment consisted of three phases: training, distraction, and the main task. After the training and distraction phases, participants were instructed to check the virtual environments freely as if they were in their natural environment. Primary dependent variables in the current study included several indices of frequency and duration of checking behaviors. We examined construct validity for the task by comparing the novel behavioral measures with standardized self-report and interviewer-rated measures. RESULTS: Results indicated that (1) OCD patients demonstrated significantly greater problems with compulsive checking compared to controls, and (2) performance on the task was positively correlated with both self-reported symptoms and interviewer-rated measures associated with OCD. CONCLUSIONS: This study provides preliminary data to support the use of this task as a new possible behavioral measure of compulsive checking behavior in OCD. If we merge the traditional behavioral research with this novel and ecologically valid method, it could improve the assessment of OCD in both clinical and research setting.

Development of a computer based symmetry arrangement symptoms measures in obsessive-compulsive disorder.

BACKGROUND: Epidemiological studies indicated that compulsive ordering and arranging, and a preoccupation with symmetry are common presentations of obsessive-compulsive disorder (OCD). OBJECTIVE: The goal of the current study was to develop and obtain preliminary psychometric data for the objective and quantitative measurement of symmetry and arrangement symptoms in OCD. METHOD: Twenty-eight normal volunteers were administered computer based assessment tasks with 4 different conditions with or without target and distraction. Primary dependent variables included several indices of time and click of arranging behaviors. Construct validity for the task was examined by comparing the novel behavioral measures with standardized measures such as Symmetry, Ordering and Arranging Questionnaire (SOAQ), Obsessive Compulsive Inventory-Revised (OCI-R), Beck depression Inventory (BDI), Beck Anxiety Inventory (BAI) and Quality of life scale (QOL). RESULT: We found significant positive correlation between behavioral parameters and standardized scales for OCD (total time and SOAQ: r(2)=0.623, P<0.001; total number of clicks and 'ordering' subscore of OCI-R: r(2)>=0.541, P<0.01). There was no significant correlation between behavioral parameters and other scales measuring constructs less relevant to ordering and arranging. A main effect of target only was observed on behavioral parameters. CONCLUSION: This study therefore provides preliminary data to support the use of this task as a novel behavioral measure of compulsive symptoms related with symmetry, ordering and arranging.

Measuring recognition of body changes over time: A human-computer interaction tool using dynamic morphing and body ownership illusion.

Measuring body image is crucial at both personal and social levels. Previous studies have attempted to quantitatively measure body image but methods for measuring body change recognition over time have not yet been established. The present study proposes a novel human-computer interaction technique using dynamic morphing and body ownership illusion, and we conducted a user study to investigate how body ownership illusion and gender would affect to body change recognition. The results showed that a participant's body change recognition was weak when the body ownership illusion was strong. In addition, female participants were less sensitive than male participants. With our proposed technique, we demonstrated that we were able to quantitatively measure body change recognition and our empirical data indicated that body change recognition varied depending on body ownership illusion and gender, suggesting that our methodology could not only be used in future body image studies but also in eating disorder treatments.

Controlling the Sense of Embodiment for Virtual Avatar Applications: Methods and Empirical Study.

BACKGROUND: The sense of embodiment (SoE) is the feeling of one's own body, and research on the SoE extends from the rubber hand illusion to the full-body ownership illusion with a virtual avatar. OBJECTIVE: The key to utilizing a virtual avatar is understanding and controlling the SoE, and it can be extended to several medical applications. In this study, we aimed to clarify these aspects by considering the following three subcomponents of SoE: sense of agency, ownership, and self-location. METHODS: We defined a human avatar (HA), point light avatar (PLA), and out-of-body point light avatar (OBPLA) and compared them in three user studies. In study 1, 28 participants were recruited and the three avatar conditions (HA, PLA, and OBPLA) were compared. In study 2, 29 new participants were recruited, and there were two avatar conditions (HA ad PLA) and two motion synchrony conditions (synchrony and asynchrony). In study 3, 29 other participants were recruited, and there were two avatar conditions (PLA and OBPLA) and two motion synchrony conditions (synchrony and asynchrony). Dependent measures included sense of agency, ownership, and self-location; emotional response; presence; and simulator sickness. RESULTS: The findings of study 1 showed that the three avatar generation methodologies can control the sense of ownership and self-location in a stepwise manner while maintaining a high sense of agency. In studies 2 and 3, we found dependencies among the three subcomponents of SoE and observed that they affected users' subjective experiences. CONCLUSIONS: Our findings may have implications for boosting the effects of virtual avatar applications in medical areas, by understanding and controlling the SoE with a full-body illusion.

Impact of Body Size Match to an Avatar on the Body Ownership Illusion and User's Subjective Experience.

The current study sought to investigate the effects of matching body movement and body size between an avatar and a participant on the body ownership illusion (BOI), the body size illusion, the sense of presence, simulator sickness, and emotional responses within an immersive virtual reality (IVR). Forty participants experienced their life-sized virtual avatars from a first-person perspective using a full-body motion-capture system. The experiment used a 2 (Motion: Synchrony and Asynchrony) × 2 (Size: Matched and Unmatched) within-subject design. Each participant completed a self-reported questionnaire that evaluated BOI, body size illusion, presence, simulator sickness, and emotional valence. Results showed that matching participant's motion to that of an avatar increased the BOI and sense of presence, while reducing simulator sickness. Furthermore, participants reported more positive emotions when motion was synchronized to the virtual avatar. Most notably, synchronizing body movement between participants and avatars resulted in strong body size illusion even when the body size of an avatar was larger than the one of a participant. To the best of our knowledge, this is the first study to directly link synchronization of user motion and body size to a virtual avatar with user's subjective experience (BOI, body size illusion, sense of presence, simulator sickness, and valence) in IVR. Our findings suggest beneficial effects of synchronized body motion and matched body size between a user and avatar on user's subjective experience in IVR, which can possibly boost the effects of virtual reality applications in the fields of entertainment, psychotherapy, and education.

Feasibility of a Virtual Reality Program in Managing Test Anxiety: A Pilot Study.

Test anxiety has been a growing problem in school-aged children, especially for students in East-Asian countries where the pressure for academic achievement is high. These students are more vulnerable to academic stress, which could further lead to anxiety disorders. For this reason, this study examined the feasibility of virtual reality (VR) test anxiety program in managing anxiety in students. A total of 22 typically developing children with varying levels of test anxiety and no history of psychiatric illnesses participated in the study (mean age = 11.6 and standard deviation [SD] = 1.84). A self-reported questionnaire measuring test anxiety, state-trait anxiety, and depression was administered. Heart rate (HR) variability and subjective anxiety were also measured to examine the changes during each of the anxiety-inducing (Exam 1 and Exam 2) and meditation (Med 1 and Med 2) sessions in the program. There was a significant difference in self-perceived anxiety during the program (p < 0.001), as well as a significant main effect of time on the standard deviation of R-R interval (p = 0.002). In addition, a significant relationship between changes in HR and perceived anxiety during Exam 1 (p = 0.003), Med 1 (p < 0.001), and Med 2 (p = 0.011) was found. In conclusion, this work demonstrates the feasibility of the virtual environment to induce different levels of anxiety and explores the potential use of VR program as a viable method to manage the negative emotion in students. This work shows the potential of technology-enhanced tools in addressing psychological problems in school-aged children. Further study is needed to validate the use of the program in clinical practice.

Joint Attention Virtual Classroom: A Preliminary Study.

OBJECTIVE: Previous studies have suggested that a virtual classroom is immersive and ecologically valid neuropsychological assessment, but those studies have limited components for social attentions. Therefore, the objective in the current study is the development of a joint attention virtual reality (JA-VR) classroom to incorporate social attentions between a participant and a virtual avatar teacher. METHODS: Fifty-eight participants were recruited for current study (25 for pilot and 33 for main studies; 32.8% female, n=19; age: M=24.5, SD=4.0). We suggested a JA-VR classroom, and compared it with previous methods including a VR classroom without JA components. We conducted attention experiments with AX-version of continuous performance tasks. RESULTS: Our results suggest that the new JA-VR classroom had convergent validity with previous methods, and that the JA-VR classroom promoted attentional processing among participants better than both old VR and non-VR measures. CONCLUSION: We add an important social attention concept to the virtual classroom, and believe that this work is an methodological foundation for the study of social attention in school life. We hope it ultimately help people with mental handicaps in social attention.

Development of Virtual Reality Continuous Performance Test Utilizing Social Cues for Children and Adolescents with Attention-Deficit/Hyperactivity Disorder.

Virtual reality (VR) neuropsychological assessments have the potential for the ecological measurement of attention. We analyzed the newly developed VR continuous performance test (VR-CPT) for Korean children with attention-deficit/hyperactivity disorder (ADHD) and typically developing children (TDC). To identify specific features of a virtual environment that influence the attention performance of children, we investigated whether the presence of a virtual teacher and social cues in the VR environment affects their attention performance. A total of 38 participants (18 TDC and 20 ADHD children and adolescents) were recruited for VR-CPT testing. Bivariate correlational analysis was conducted to examine the associations between the results of the VR-CPT and ADHD questionnaires to determine the capacity of VR-CPT to mirror real-life attention behaviors. Mixed-design analysis of variables was conducted to compare the effects of the social aspects of the VR-CPT on attention performance in groups. There were significant associations between ADHD rating scores and the omission error, commission error, reaction time (RT), reaction time variability (RTV), and total accuracy of the VR-CPT in the ADHD group. In addition, the ADHD group exhibited comparable performance with the TDC group for all measures of the VR-CPT. Also there seemed to be a trend of decreasing RTV when a virtual teacher with social cues was present compared with the equipment control condition in the ADHD group. Performance in the VR-CPT program was associated with behavioral measures of ADHD symptoms. Adding social aspects to a VR environment commonly encountered by children and adolescents has the potential to make a difference in the attention performance of youths with ADHD.

Spatial Learning and Memory Using a Radial Arm Maze with a Head-Mounted Display.

OBJECTIVE: A radial arm maze (RAM) is an essential tool for assessing spatial learning and memory. Although this tool is widely used to study deficits in spatial memory in animal models, it has several restrictions that prevent its adaptation to human research and training. Therefore, we developed a head-mounted-display RAM (HMD-RAM) program for humans and verified its validity by comparing it to the results obtained by previous RAM studies. We also compared the HMD and a flat monitor as experimental devices. METHODS: Forty participants were recruited for the current study (Study 1: 20 participants with the HMD device; Study 2: 20 participants with the flat monitor). They navigated a virtual room as a first-person viewer and used environmental landmarks to remember their spatial position and orientation. The main dependent measures were working memory error, reference memory error, detection time, travel distance, and participant's head movements. To validate the program, participants also conducted neuropsychological assessments and self-reported measures. RESULTS: The results for HMD-RAM tasks were consistent with the results of previous research conducted on animals, and the HMD elicited a higher sense of presence, immersion, and simulator sickness than the flat monitor. According to post-experiment questions on navigation strategy, creating landmarks was important when people were discovering locations in their environment, and an HMD was beneficial for better navigation strategy. CONCLUSION: These results suggest that the HMD-RAM is valuable for estimating spatial learning and memory in humans and may be a useful tool for early diagnosis of deficits in spatial learning and memory, including amnestic mild cognitive impairment and Alzheimer's disease.

Virtual environment training system for rehabilitation of stroke patients with unilateral neglect: crossing the virtual street.

In this paper, we propose a system for training of stroke patients with unilateral neglect by using technology of virtual reality (VR). The proposed system is designed to compensate for unilateral neglect. This system contains the calibration of unilateral neglect and the training of this disease. The calibration procedure is implemented by aligning the virtual object at a subjective middle line. The training procedure is implemented by completing the missions that are used to keep the virtual avatar safe during crossing the street in a virtual environment. The results of this study show that the proposed system is effective to train unilateral neglect. The left to right ratio scores extracted from this system gradually decrease as the sessions of training are repeated. To validate the VR system parameters, the parameters are analyzed by correlation with those of traditional unilateral neglect assessment methods (such as the line bisection test and the cancellation test).

Characteristics of social perception assessed in schizophrenia using virtual reality.

Impairment in social skills is one of the few criteria that all individuals diagnosed with schizophrenia must meet. Successful social skills require the coordination of many abilities, including social perception, which involves the decoding and interpretation of social cues from others. In this study, we examined the potential for virtual reality (VR) in social skill training. We attempted to determine if VR can be used to measure social skills and social perception, and to determine which VR parameters are related to schizophrenic symptoms. Some of these results have clear clinical relevance, while other observations need further study. The VR system appears to be useful in assessing the social perception of schizophrenics and normal people, and could be more widely used in the future for social training and in the assessment of social problem-solving abilities, assertiveness skills, and general social skills.

Performance-Based Animation Using Constraints for Virtual Object Manipulation.

Optical motion-capture systems can be used to animate characters in real time based on human demonstrations. However, most approaches do not consider the detailed finger movements necessary for object manipulation. The proposed online motion-capture framework encourages natural motions by automatically guiding the avatar's motion toward the desired behavior based on a set of captured reference motions for the same behavior. The proposed motion controller imitates the user's finger and body gestures to enable performance-based animation of human avatars that can manipulate virtual objects in real time.

Brief Report: Joint Attention and Information Processing in Children with Higher Functioning Autism Spectrum Disorders.

Theory suggests that information processing during joint attention may be atypical in children with Autism Spectrum Disorder (ASD). This hypothesis was tested in a study of school-aged children with higher functioning ASD and groups of children with symptoms of ADHD or typical development. The results indicated that the control groups displayed significantly better recognition memory for pictures studied in an initiating joint attention (IJA) rather than responding to joint attention (RJA) condition. This effect was not evident in the ASD group. The ASD group also recognized fewer pictures from the IJA condition than controls, but not the RJA condition. Atypical information processing may be a marker of the continued effects of joint attention disturbance in school aged children with ASD.

Human field of regard, field of view, and attention bias.

BACKGROUND AND OBJECTIVE: Human field of regard (FOR) is an important concept that should be considered along with field of view (FOV) for people with/without handicaps, but previous studies have neglected this aspect of human perception. In the current study, we suggest and test a new virtual reality (VR) software with which to evaluate individual's detection abilities in the human FOR. METHODS: We conducted measurements of human FOV, FOR, and FOR with visual cue (FOR-cue), and we evaluated healthy adults' responses in a first experiment. Participants were asked to detect targets on a head-mounted display (HMD) as quickly as possible in three conditions: (a) FOV: the head rotation doesn't change the view of the screen in the HMD; (b) FOR: the head rotation changes the view of the screen in the HMD; and (c) FOR-cue: same with the FOR condition but an endogenous visual cue indicating the direction of stimulus. To address the need to increase the number of trials in the FOR condition, we also conducted a second experiment with new samples and four times of trial numbers. RESULTS: The participants' detection time results indicated that the FOV condition was faster than the FOR-cue and FOR conditions, and the FOR-cue was faster than the FOR condition. Interestingly, we found a unique characteristic in the FOR conditions that did not exist in the FOV condition: The target responses were faster for the left side than the right side. The results of the second experiment were consistent with the first, and head motion trajectory analysis showed that participants had more movement toward the left side than the right side in the early parts of each trial. CONCLUSIONS: In this study, we suggested a new virtual reality (VR) evaluation technique and measured the human searching pattern in the FOR condition. We found a unique left-side attention bias in the FOR condition, and discussed implication of these results and potential attention bias factors. We believe this work is an important foundation for interactive 3D UI design, and we hope it will help people who have FOR handicaps.

A Virtual Joy-Stick Study of Emotional Responses and Social Motivation in Children with Autism Spectrum Disorder.

A new virtual reality task was employed which uses preference for interpersonal distance to social stimuli to examine social motivation and emotion perception in children with Autism Spectrum Disorders. Nineteen high function children with higher functioning Autism Spectrum Disorder (HFASD) and 23 age, gender, and IQ matched children with typical development (TD) used a joy stick to position themselves closer or further from virtual avatars while attempting to identify six emotions expressed by the avatars, happiness, fear, anger, disgust, sadness, and surprise that were expressed at different levels of intensity. The results indicated that children with HFASD displayed significantly less approach behavior to the positive happy expression than did children with TD, who displayed increases in approach behavior to higher intensities of happy expressions. Alternatively, all groups tended to withdraw from negative emotions to the same extent and there were no diagnostic group differences in accuracy of recognition of any of the six emotions. This pattern of results is consistent with theory that suggests that some children with HFASD display atypical social-approach motivation, or sensitivity to the positive reward value of positive social-emotional events. Conversely, there was little evidence that a tendency to withdraw from social-emotional stimuli, or a failure to process social emotional stimuli, was a component of social behavior task performance in this sample of children with HFASD.