Tunnel Vision: Sharper Gradient of Spatial Attention in Autism

Abstract

Enhanced perception of detail has long been regarded a hallmark of Autism Spectrum Conditions (ASC), but its origins are unknown. Normal sensitivity on all fundamental perceptual measures -- visual acuity, contrast discrimination, and flicker detection -- are strongly established in the literature. If individuals with ASC do not have superior low-level vision, how is perception of detail enhanced? We argue that this apparent paradox can be resolved by considering visual attention, which is known to enhance basic visual sensitivity, resulting in greater acuity and lower contrast thresholds. Here, we demonstrate that the focus of attention and concomitant enhancement of perception are sharper in human individuals with ASC than matched controls. Using a simple visual acuity task embedded in a standard cueing paradigm, we mapped the spatial and temporal gradients of attentional enhancement by varying the distance and onset time of visual targets relative to an exogenous cue, which obligatorily captures attention. Individuals with ASC demonstrated a greater fall-off in performance with distance from the cue than controls, indicating a sharper spatial gradient of attention. Further, this sharpness was highly correlated with the severity of autistic symptoms in ASC, as well as autistic traits across both ASC and control groups. These findings establish the presence of a form of “tunnel vision” in ASC, with far-reaching implications for our understanding of the social and neurobiological aspects of autism.

A computational perspective on autism

“…S1). Consistent with the findings of Robertson et al (45), the population gain decreased for both models as the distance between the target and attentional cue increased, with faster falloff in the autism model (Fig. 5C).…”

“…Additional simulations examining how changes in the extent of neuronal pooling and the semisaturation constant affect the model responses are shown in SI Appendix, Fig. S3 D and E. It is further interesting to note that our results may explain the apparent conflict between the study by Robertson et al (45) and another recent study suggesting that exogenous spatial attention may not be affected in autism (46). Specifically, because the attentional field was the same for the control and autism models, the differences in their responses were entirely due to the difference in their suppressive field gain terms.…”

“…Recently, Robertson et al (45) found that, as the distance between the attentional cue and target increases (SI Appendix, Fig. S3A), the rate at which performance falls off is greater for subjects with autism than typically developing controls, suggesting there is a sharper gradient of attention in autism, or "tunnel vision."…”

“…S3B). This manipulation is similar to the measures Robertson et al (45) took to match baseline task difficulty across subjects. Importantly, under this condition, the modeling results remained consistent with the psychophysical findings; namely, a steeper gradient in the population gain for the autism than the control model, which increased as the suppressive field gain term decreased (SI Appendix, Fig.…”

Exogenous spatial attention: Evidence for intact functioning in adults with autism spectrum disorder

“…The spatial attention literature in ASD is full of inconsistent findings (for reviews, see Ames & FletcherWatson, 2010;Fan, 2012;Keehn et al, 2013;Simmons et al, 2009). Despite this large body of empirical work, only a handful of previous studies have assessed exogenous spatial attention function in ASD by pairing a peripheral precue with a covert discrimination task (Haist, Adamo, Westerfield, Courchesne, & Townsend, 2005;Iarocci & Burack, 2004;Renner, Grofer, Klinger, & Klinger, 2006;Robertson, Kravitz, Freyberg, BaronCohen, & Baker, 2013;Townsend, Harris, & Courchesne, 1996, task 2). Inconsistent with our results, ASD-associated deficits in exogenous attention were reported in all but one (Iarocci & Burack, 2004) of these previous studies.…”