Negative Emotionality Disrupts Pattern Separation in Adults Diagnosed with Autism Spectrum Disorders

Background:  Cognitive function is frequently and broadly disrupted in autism spectrum disorder (ASD) in areas of cognitive control, attention, and memory. However, many questions of specificity remain: which cognitive functions are disrupted for which individuals in which dimensions of function. Growing evidence indicates that significant levels of anxiety in ASD may be associated with difficulties in cognitive decision making in a circuit involving amygdala, hippocampus, and medial frontal lobes.  

Objectives:  This study aims to discover how pattern separation memory—the ability to keep sets of similar memories distinct from each other--is affected by emotion regulation in ASD.

Methods:  Participants for the memory task included 70 adults ages 17 to 36, including 25 adults diagnosed with an ASD and 45, age- and IQ-matched college student controls. There were no significant between-group differences in age or Full Scale IQ. Participants viewed digital images of everyday objects appearing one at a time. Three categories of images appeared in random order: One group of images (foils) only appeared once during the experiment. A second group of images (repeats) appeared twice throughout the study. The final group (lures) consisted of paired images that were visually and conceptually similar but not identical to previously-shown images. For each image, participants were asked to determine if the image was new, old, or similar. 42 participants (24 ASD and 18 Control) completed an additional battery of emotion symptom questionnaires. 

Results:  On the memory task, the ASD and control groups performed similarly when responding to novel “foil” stimuli. However, when responding to “repeat” stimuli, the ASD group chose “new” and “similar” (incorrect answers) significantly more often than controls. The ASD group also chose “new” more often than controls for the “lure” stimuli. Analysis of these errors in relation to the survey data showed significant associations between the repeat-as-new and lure-as-new choices with cognitive worry, state and trait anxiety, depression, and BAS activation arousal score. The control group had no such correlations between memory scores and emotion regulation measures. 

Conclusions:  The ASD group’s increased tendency to identify as “new” many stimuli that were either identical or very similar to ones seen before seems to indicate particular problems with memory. Some of this trouble may reflect distraction due to emotion regulation difficulties in the ASD group. We have previously suggested that decision making in autism reflects a risk-avoidance strategy that may be in play here, in that the ASD group tries to avoid being tricked by new stimuli and thus oversamples from that choice. This unique association between negative emotionality and everyday cognitive memory skills suggests the need for further exploration of memory substrates in ASD but also for intervention tailored to a risk-avoidance style.