Recognizing Biological Motion and Emotions from Point-Light Displays in Autism Spectrum Disorders

<div><p>One of the main characteristics of Autism Spectrum Disorder (ASD) are problems with social interaction and communication. Here, we explored ASD-related alterations in ‘reading’ body language of other humans. Accuracy and reaction times were assessed from two observational tasks involving the recognition of ‘biological motion’ and ‘emotions’ from point-light displays (PLDs). Eye movements were recorded during the completion of the tests. Results indicated that typically developed-participants were more accurate than ASD-subjects in recognizing biological motion or emotions from PLDs. No accuracy differences were revealed on two control-tasks (involving the indication of color-changes in the moving point-lights). Group differences in reaction times existed on all tasks, but effect sizes were higher for the biological and emotion recognition tasks. Biological motion recognition abilities were related to a person’s ability to recognize emotions from PLDs. However, ASD-related atypicalities in emotion recognition could not entirely be attributed to more basic deficits in biological motion recognition, suggesting an additional ASD-specific deficit in recognizing the emotional dimension of the point light displays. Eye movements were assessed during the completion of tasks and results indicated that ASD-participants generally produced more saccades and shorter fixation-durations compared to the control-group. However, especially for emotion recognition, these altered eye movements were associated with reductions in task-performance.</p></div

Accuracy of the tone-counting task during the automatization task during single- and dual-task writing.

<p>Mean and standard errors are presented. For accuracy of the tone-writing task (%) a significant Time x Task interaction was found (F = 9.17, p<0.01), showing improved performance in dual-task accuracy from the pre to post and pre to retention tests in both groups. * indicates significant increase with p<0.05.</p

Across all participants, <b>figure 4</b> displays the linear fits for the relationship between accuracy on the <i>Emotion recognition test</i> (y-axis) and eye movements (x-axis) (saccades/second (A); fixation duration (B)).

<p>Dotted lines denote 0.95 confidence intervals.</p

Coefficient of variation of the writing amplitude on the transfer task during the pre, post and retention tests for both groups.

<p>Mean and standard errors are presented. For COV_ampl a significant main effect of time was found (F = 5.54, p = 0.03), showing improvements in variability of amplitude from pre to retention test in both groups. * indicates significant decrease with p<0.05.</p

Eye movements.

<p>Saccades/second (<b>A–B</b>), and fixation durations (<b>C–D</b>) are displayed for all tests as a function of participant group (Autism spectrum disorders (<b>ASD</b>); Typically developed (<b>TD</b>)). Vertical lines denote ±standard error.</p

Writing tasks that were assessed by means of the touch-sensitive writing tablet.

<p>(A) Single-task writing with visual target zones, (B) Single-task writing without visual target zones, (C) Dual-task writing, (D) Single-task tone counting. The small circle indicates the starting point of the writing sequence and the colored target zones indicate the requested writing amplitude in the conditions with cues.</p

Exemplary point light display.

<p>(<b>A</b>) Photograph of the male actor with the 12 markers attached to the body and (<b>B</b>) the corresponding point light figure.</p

Writing amplitude on the transfer task in the presence and absence of cues for both groups.

<p>Mean and standard errors are presented. For writing amplitude (% of target size) a significant Group x Cue interaction was found (F = 4.42, p = 0.04), showing improved performance in the presence of cues in the PD+FOG only. * indicates significant increase with p<0.05.</p

Clinical characteristics of patients with Parkinson with and without FOG.

<p>Clinical characteristics of patients with Parkinson with and without FOG.</p

Across all participants, <b>figure 5</b> displays the linear fits for the relationship between scores on the social responsiveness scale (SRS) (x-axis) and accuracy (y-axis) on the <i>Biological motion recognition test</i> (A) and the <i>Emotion recognition test</i> (B).

<p>Dotted lines denote 0.95 confidence intervals.</p