Table 4.
Descriptive statistics for webcam-collected performance measures across cases with and without Intellectual Disability (ID).
| No ID n=224 |
ID n=151 |
|||||
|---|---|---|---|---|---|---|
| M (sd) | M (sd) | Raw Δ | t (p) | Cohen’s d | ||
| Overall Attention (%) | 82.1 (14) | 70.5 (17) | +11.6% (1.8 min total) | 7.1 (<.001) | .75 | |
| Attentional Scanning (Count) | 11.6 (3.4) | 7.9 (2.5) | +3.7 glances to each target | 9.9 (<.001) | 1.20 | |
| Positive Emotion (%) | 6.4 (8.7) | 10.3 (9.1) | −3.9% intensity | −4.2 (<.001) | −.44 | |
| Negative Emotion (%) | 2.2 (3.0) | 3.4 (4.1) | −1.2% intensity | −3.3 (.001) | −.35 | |
| Social Attention (z) | −.02 (1.0) | −1.52 (1.3) | +1.5 control SDs | 11.9 (<.001) | 1.14 | |
| Social Preference (FD) | 1.4 (0.3) | 1.2 (0.3) | +0.2 seconds per AOI | 6.0 (<.001) | .68 | |
| Face Preference (FD) | 1.3 (0.8) | 0.8 (0.5) | +0.5 seconds per AOI | 6.1 (<.001) | .70 | |
| Non-social Preference (FD) | 1.1 (0.4) | 1.2 (0.4) | −0.1 seconds per AOI | −2.1 (.038) | −.24 | |
| Receptive Vocabulary (FD) | 41.9 (25.7) | 17.1 (13.6) | +24.8 seconds to all targets | 10.1 (<.001) | 1.13 | |
| Speed to Faces (TFF) | 7.2 (2.1) | 8.0 (1.8) | −0.8 seconds per AOI | −3.3 (<.001) | −.37 | |
| Speed to Object (TFF) | 4.9 (1.3) | 6.1 (1.2) | −1.2 seconds per AOI | −7.2 (<.001) | −.87 | |
| Reading Accuracy (FD) | 37.9 (22.8) | 16.6 (14.1) | +21.3 seconds to all targets | 9.2 (<.001) | 1.06 | |
Note. ID=Intellectual disability (defined as parent-report of ID/GDD or estimated IQ<170). Overall attention (%) is the percentage of time on screen throughout all stimulus paradigms. Count=sum of glances to all targets averaged across stimuli. TFF=time to first fixation – values represent averages across all stimuli, including those that were not fixated where the length of the stimulus was imputed. AOI=area-of-interest. Values for positive and negative emotion represent estimated intensities with a range of 0–100%. Higher values are preferable for all measures except Speed to Faces and Speed to Objects where higher values indicate slower time to the AOIs, Non-Social Preference where higher values indicate a preference for non-social information, and Positive and Negative Emotion measures where higher scores simply indicate more expressiveness. Social attention is presented as a z-score (based on the neurotypical control mean) because this measure is created by averaging multiple different metrics (fixation duration, fixation count, and time-to-first fixation) after standardization.