Local or global hierarchical visual processing in nine- and twelve-month old infants (2013)

Undergraduate: Margaret O'Brien

Faculty Advisor: J. Steven Reznick
Department: Psychology & Neuroscience

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Previous research suggests that adults see objects in their perceptual worlds first as a global whole before noticing aspects of objects¿ local parts, and that infants younger than 12 months see objects first as local parts before mentally ¿assembling¿ them into global wholes. Finding when this switch occurs could be important in the field of research on Autism Spectrum Disorder (ASD) because research suggests children with ASD never make the switch, keeping their local-oriented perceptual bias as adults. This study used an infant-controlled habituation paradigm to assess local and global biases of 9- and 12-month old infants in two different ways: 1) a visual habituation procedure with images on a computer screen, and 2) a manual habituation procedure with physical toys. Local versus Global preferences were assessed using three indexes: 1) visual habituation visual attention, 2) manual habituation visual attention, and 3) manual habituation manual attention. Results suggest a slightly global preference for 12-month-olds and a slightly local preference for 9-month-olds. There is also a trend for females to become globally-oriented earlier than males and for the global bias to start earlier in manual than visual capacities. Although most of these results were not statistically significant, the trends were very promising and consistent with the previous research.