Animacy Processing in Autism: Event-Related Potentials Reflect Social Functioning Skills

Abstract

Though previous studies with autistic individuals have provided behavioral evidence of animacy perception difficulties, the spatio-temporal dynamics of animacy processing in autism remain underexplored. This study investigated how animacy is neurally encoded in autistic adults, and whether potential deficits in animacy processing have cascading deleterious effects on their social functioning skills. We employed a picture naming paradigm that recorded accuracy and response latencies to animate and inanimate pictures in young autistic adults and age- and IQ-matched healthy individuals, while also employing high-density EEG analysis to map the spatio-temporal dynamics of animacy processing. Participants' social skills were also assessed through a social comprehension task. The autistic adults exhibited lower accuracy than controls on the animate pictures of the task and also exhibited altered brain responses, including larger and smaller N100 amplitudes than controls on inanimate and animate stimuli, respectively. At late stages of processing, there were shorter slow negative wave latencies for the autistic group as compared to controls for the animate trials only. The autistic individuals' altered brain responses negatively correlated with their social difficulties. The results suggest deficits in brain responses to animacy in the autistic group, which were related to the individuals' social functioning skills.

Keywords: animacy; autism; event-related potentials; picture naming; social skills.

Figure 1

The picture naming task procedure.

Figure 2

Accuracy (%) in animate trials in the autistic and control groups.

Figure 3

Accuracy (%) in inanimate trials in the autistic and control groups.

Figure 4

Grand-average ERPs from the picture naming task. The blue and red lines represent the control’s and the target/autistic group’s ERP responses across the animate (solid line) stimuli and the inanimate (dashed line) stimuli.

Figure 5

Correlation between the autistic adults’ left frontotemporal slow positive wave amplitudes on the inanimate trials and their scores in the social comprehension task.

Figure 6

Correlation between the autistic adults’ response latencies on the animate trials of the picture naming task and their scores in the social comprehension task.