Elsevier

Vision Research

Volume 51, Issue 5, 2 March 2011, Pages 470-478
Vision Research

Orientation tuning in the visual cortex of 3-month-old human infants

https://doi.org/10.1016/j.visres.2011.01.003Get rights and content
Under an Elsevier user license
open archive

Abstract

Sensitivity to orientation is critical for making a whole and complete picture of the world. We measured the orientation tuning of mechanisms in the visual cortex of typically developing 3-month-olds and adults using a nonlinear analysis of the two-input steady-state Visually Evoked Potential (VEP). Two gratings, one a fixed test and the other a variable orientation masker were tagged with distinct temporal frequencies and the corresponding evoked responses were measured at the harmonics of the test and masker frequencies and at a frequency equal to the sum of the two stimulus frequencies. The magnitude of the sum frequency component depended strongly on the relative orientation of the test and masker in both infants and adults. The VEP tuning bandwidths of the 3-month-olds measured at the sum frequency were similar to those of adults, suggesting that behavioral immaturities in functions such as orientation discrimination and contour integration may result from other immaturities in long-range lateral projections or feedback mechanisms.

Research highlights

► Orientation tuning in human infants and adults was recorded via VEP. ► Infant VEP bandwidths were found to be within a factor of two adults’ bandwidths. ► Smaller stimuli were found to increase the VEP orientation tuning bandwidths.

Keywords

Orientation tuning
Visually Evoked Potential
Receptive field
Non-classical surround

Cited by (0)