Evaluative Conditioning in Persons with ASD

Background:

Studies on individuals with Autism Spectrum Disorder (ASD) report preferences for nonsocial stimuli (i.e., a bell) compared to social stimuli (i.e., a voice; Werner, Dawson, Osterling, & Dinno, 2000).  The capacity for persons with ASD to learn social information, despite this lack of preference, is less clear.  Indeed, findings have been mixed regarding whether individuals with ASD have difficulty distinguishing between emotions (Harms, Martin, & Wallace, 2010; Rump, Giovannelli, Minshew & Strauss, 2009).  Social learning  has been assessed in typically developing individuals through evaluative conditioning and priming tasks, but these tasks have not been extensively used in persons with ASD (Field 2006; Kamio, Wolf, & Fein, 2006).  Evaluative conditioning tasks present a neutral stimulus followed by a stimulus that requires an evaluative judgment (e.g., social stimuli) that is then associated with the neutral stimulus.

Objectives:

For the current study, we used an evaluative conditioning task to test whether persons with ASD show social learning when neutral cartoon characters are associated with faces displaying happy expressions as opposed to angry expressions.  We predicted that individuals with typical development would prefer characters associated with the happy face.  If social learning is impaired in ASD, we predicted that individuals with ASD would show no preference for characters associated with a happy or angry face.

Methods:

Sixteen high functioning young adults with ASD and 15 age-matched young adults with typical development completed a computer task that paired cartoon characters with happy faces, angry faces, or a nonsocial stimulus (i.e., a gray box).  Across 315 trials, each of the 12 cartoon characters was paired with either a happy face, angry face, or gray box approximately 26 times.  After the learning phase, participants completed forced choice/likert ratings indicating which characters they preferred.

Results:

Emotional expression did not affect preferences for either diagnostic group.  However, a significant interaction of diagnosis with social versus nonsocial pairing was indicated, F(1, 29)=4.12, p=.05, η_p²=.12, with significantly higher preferences reflected in the ASD sample for characters paired with nonsocial (gray square) stimuli (M=67.81, SD=17.28) compared to social (faces) stimuli (M=57.48, SD=13.81).  Typically developing participants preferred characters paired with social stimuli (M=59.55, SD=11.68) over nonsocial stimuli (M=50.17, SD=23.69), though this difference was not significant.

Conclusions:

Results of this study suggest that persons with ASD showed evidence of evaluative conditioning, with those characters paired with a nonsocial stimulus being preferred to those characters paired with faces.  That is, learning occurred but individuals with ASD did not show a preference for any characters associated with social stimuli.  While research on preferences for nonsocial stimuli in persons with ASD has largely focused on children, this study lends support for the nonsocial preference continuing into young adulthood and affecting learned information.