Affective Responses by Adults with Autism Are Reduced to Social Images but Elevated to Images Related to Circumscribed Interests
Bodfish JW (2012) Affective Responses by Adults with Autism Are Reduced to Social Images but Elevated to Images Related to
Circumscribed Interests. PLoS ONE 7(8): e42457. doi:10.1371/journal.pone.0042457
Affective Responses by Adults with Autism Are Reduced to Social Images but Elevated to Images Related to Circumscribed Interests
Noah J. Sasson 0
Gabriel S. Dichter 0
James W. Bodfish 0
Frank Krueger, George Mason University/Krasnow Institute for Advanced Study, United States of America
0 1 School of Behavioral and Brain Sciences, The University of Texas at Dallas, Richardson, Texas, United States of America, 2 Carolina Institute for Developmental Disabilities, School of Medicine, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina , United States of America
Individuals with autism spectrum disorders (ASD) demonstrate increased visual attention and elevated brain reward circuitry responses to images related to circumscribed interests (CI), suggesting that a heightened affective response to CI may underlie their disproportionate salience and reward value in ASD. To determine if individuals with ASD differ from typically developing (TD) adults in their subjective emotional experience of CI object images, non-CI object images and social images, 213 TD adults and 56 adults with ASD provided arousal ratings (sensation of being energized varying along a dimension from calm to excited) and valence ratings (emotionality varying along dimension of approach to withdrawal) for a series of 114 images derived from previous research on CI. The groups did not differ on arousal ratings for any image type, but ASD adults provided higher valence ratings than TD adults for CI-related images, and lower valence ratings for social images. Even after co-varying the effects of sex, the ASD group, but not the TD group, gave higher valence ratings to CI images than social images. These findings provide additional evidence that ASD is characterized by a preference for certain categories of non-social objects and a reduced preference for social stimuli, and support the dissemination of this image set for examining aspects of the circumscribed interest phenotype in ASD.
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Competing Interests: The authors have declared that no competing interests exist.
. These authors contributed equally to this work.
Introduction
Circumscribed interests (CI) are a characteristic of autism listed
within the restricted and repetitive behavior domain [1] defined by
an intense preoccupation with a narrow range of subjects. CIs
have been described from the earliest characterizations of autism
[2] exist across all levels of symptom severity and intellectual
functioning [3] [4] [5] and are ubiquitous in the disorder an
estimated 88% of individuals with an Autism Spectrum Disorder
(ASD) experience CIs [6]. While this evidence suggests that CIs
constitute an especially pervasive and prevalent clinical
characteristic of the autism phenotype, there remains a paucity of
empirical research in this area relative to other features of the
disorder [7].
The content of CI can differ across individuals and may include
idiosyncratic topics [6]. CI are defined more broadly by a narrow,
restricted, and inflexible response set in contrast to more adaptive
interests (e.g. hobbies) and by heightened motivation to pursue and
remain engaged with the idiosyncratic content which can interfere
with daily functioning [1] [7]. Indeed, despite the significant
challenges stemming from other aspects of the disorder, parents of
children with ASD cite CI as the most difficult characteristic to
manage on a daily basis [8] [9], as they often require extreme
patience, tolerance and accommodation [7]. Additionally, because
CIs may impede the development of functional behaviors [10]
[11] and peer relationships [12], and endure with age to a greater
degree than other autism symptoms [9] [13] [14], they may
represent a persistent and maladaptive characteristic of ASD
meriting greater clinical attention and intervention [15].
The intensity and restricted focus of CI relative to non-CI
stimuli suggest that abnormal cognitive-affective mechanisms may
contribute to elevated rewarded value ascribed to these stimuli in
ASD. Recent behavioral and neuroimaging findings support this
conclusion by indicating that objects related to CI are differentially
processed and prioritized by individuals with ASD. For example,
adults with ASD are characterized by relative hypoactivation in
neural reward circuits while anticipating monetary incentives and
social stimuli but hyperactivation to images related to CI [16] [17].
These findings suggest that the presence of altered functioning of
reward circuitry in ASD may constitute a potential neurobiological
mechanism of CI. Consistent with this conclusion, children and
adolescents with ASD exhibit restricted and preservative attention
to a subset of object stimuli that are common subjects of CI (e.g.,
trains and electronics) [18] [19], b (...truncated)