Visual attention

Background

There are many reports of differences in visual attention in autism compared to typical individuals, both experimentally and anecdotally. One frequent observation is that individuals with autism can focus excessively on certain stimuli in their environment, and that these stimuli can seem quite irrelevant to typical individuals. Another common observation is that individuals with autism show acute attention to fine detail. However, it is also frequently reported that individuals with autism can be highly distractible.

Attention to detail

Perhaps the most influential finding which highlighted the excessive attention to detail as a research question was the initial studies showing that children with autism can perform better than typical individuals on the Embedded Figures task. This requires picking out a small stimulus from a surrounding context. One possible reason for this ability that we have explored is that individuals with autism are better able to discriminate the small figure from other similar figures in the surrounding background. In order to investigate this further, we gave children with and without autism a series of visual search tasks, which required participants to search for a conjunctive target amongst distracters. We also varied how similar the target was to the distracters, and found that children with autism showed superior performance, even when the target and distracters were highly similar.

Top down attentional control

We have also used computerised visual attention tasks to assess whether the way in which information is presented can affect selective attention in children with autism. We have found that the amount of irrelevant information presented on a computer screen affects selection of relevant information in the same way for both typical children and children with autism. We have also found that like typical children, children with autism are more distracted by task irrelevant information that shares features with their current goals. These findings suggest that selective attention can be quite typical in children with autism. However, further studies have shown that selective attention performance can depend on the type of information presented.

Stimulus specific attentional differences

We have found that children with autism show typical attentional modulation of static information, but have difficulty with modulating dynamic information. For example, we found that both typical children and children with autism were more distracted by irrelevant colour distracters (static stimuli) when colour formed part of their current goals compared to when it did not. Typical children showed the same pattern for abrupt onset distracters (dynamic stimuli) whilst children with autism did not. Children with autism were only slightly distracted by stimuli with an abrupt onset, even when abrupt onset formed part of their current goals. We are currently investigating if this results from perceptual or attentional differences.

Related reading

Shah, A., & Frith, U. (1983). An islet of ability in autistic children: A research note. Journal of Child Psychology and Psychiatry, 24, pp.613-620.

Jolliffe, T., & Baron-Cohen, S. (1997). Are prople with autism and Asperger's Syndrome faster than normal on the embedded figures test? Journal of Child Psychology and Psychiatry, 38, pp.527-534.

Plaisted, K.C. (2001). Reduced generalization: An alternative to weak central coherence. In: Burack, J.A., Charman, A., Yirmiya, N., & Zelazo, P.R. (Eds). Development and Autism: Perspectives from theory and research. Lawrence Erlbaum Associates, New Jersey.

Plaisted, K.C., O'Riordan, M.A.F., & Baron-Cohen, S. (1998). Enhanced visual search for a conjunctive target in autism: a research note. Journal of Child Psychology and Psychiatry, 39, pp.777-783.

O'Riordan, M.A.F. & Plaisted, KC (2001). Enhanced discrimination in autism. Quarterly Journal of Experimental Psychology, Section A, 54, pp.961-979

O'Riordan, M.A.F., Plaisted K.C., Driver, J., & Baron-Cohen, S. (2001). Superior visual search in autism. Journal of Experimental Psychology: Human Perception and Performance, 27, pp.719-730.

O'Riordan, M.A.F. (2004). Superior visual search in adults with autism. Autism, 8, pp.229-248.

Greenaway, R. & Plaisted, K. (in press). Top-down attentional modulation in autistic spectrum disorders is stimulus specific. Psychological Science.