Neural Adaptation during Learning in ERPs to Visual Target Detection in Children with ASD

Background:  Previous fMRI studies have demonstrated reduced neural adaptation in adults with autism spectrum disorder (ASD) during short term learning tasks (Schipul et al., 2012; Schipul & Just, 2015). Reduced neural adaptation may impair learning abilities in ASD and possibly play a role in the emergence of behavioral characteristics of ASD.  However, it is critical to examine the neural processing underlying learning throughout development in ASD. Therefore, in the present study we use electroencephalography (EEG) to examine neural adaptations during learning in children with ASD during performance of a visual target detection task.

Objectives: The current study examines changes in event-related potentials (ERPs) over time during a visual target detection task in children with ASD and typically developing (TD) children, in order to gain insight into neural adaptability in children with ASD.

Methods:  Participants include children with ASD and TD children, ages 8 to 12 years old and with IQs in the normal range. EEG data was collected while participants performed a visual target detection task for 30 minutes. Data was collected from 128 electrode sites and was analyzed using EEGLab.  EEG waveforms were compared for both non-targets (red circle, 85% of trials) and targets (blue square, 15% of trials) between Early and Late blocks of the experiment. Data collection is ongoing and currently includes 10 ASD and 12 TD participants.

Results:  Preliminary results suggest that the ASD group (n=4) and TD group (n=4) show similar EEG waveforms to Non-Targets in Early blocks, but that the ASD group shows a similar pattern in Late blocks, while the TD group shows significant attenuation in Late blocks in both the P1 and N2 (Fig. 1). In response to Targets, the ASD group shows an attenuated P3 response relative to the TD group in Early blocks (Fig. 2). Group adaptations in the response to Targets is currently unclear. Behavioral accuracy and reaction time was similar across groups and well above chance.

Conclusions:  These preliminary findings suggest reduced adaptation over time in ERP responses to visual non-target stimuli in children with ASD. This may reflect reduced neural adaptability in ASD that may affect the learning process throughout development.  Furthermore, we found blunted ERPs to targets in ASD (despite intact behavioral performance). Future analyses will include the full final participant groups and will relate neural measures to clinical measures of ASD symptom severity and sensory features. Reduced neural adaptability in ASD may affect the learning of a variety of behaviors throughout development and may play a role in the emergence of ASD symptoms.