First Advisor

David Beversdorf

Date of Award


Document Type


Degree Name

Bachelor of Science (B.S.) in Biology and University Honors






Spatial ability, Visual perception, Attention, Autistic people, Autism spectrum disorders




Objective: We investigated visuospatial processing in individuals with autism using bisection and quadrisection tasks to evaluate the presence of a possible downward vertical spatial bias that could provide insights into the preference for attending to the mouth in ASD populations.

Methods: Twenty participants with ASD and 20 age, IQ, and sex-matched control participants were recruited (ages 6-23). Participants were asked to bisect, quadrisect from the top, and quadrisect from the bottom vertical lines placed in their left, center, and right visual spaces. Distance from the true midpoint and quadripoint were calculated and compared between the two groups.

Results: No significant difference was found between the ASD and control groups for vertical line bisections or bottom quadrisections. However, ASD participants had a greater deviation above the true top quadripoint than control participants for top quadrisections (t(37)=1.74, p=0.045).

Conclusion: Our results indicate that there is no downward spatial bias in ASD populations, and thus attentional biases are likely not contributing to the mouth preference exhibited by individuals with ASD. Rather, for the top quadrisections there is an upward bias in the ASD group. This may be due to the more local attentional demands of the quadrisection task but needs further investigation.


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An undergraduate honors thesis submitted in partial fulfillment of the requirements for the degree of Bachelor of Science in University Honors and Biology & Public Health Studies: Pre-Clinical Health Science.

Persistent Identifier