Referenced in: none

Automatically associated channels: TASK1

Title: NMDA receptor antagonist ketamine impairs feature integration in visual perception.

Authors: Julia D I Meuwese, Anouk M van Loon, H Steven Scholte, Philipp B Lirk, Nienke C C Vulink, Markus W Hollmann, Victor A F Lamme

Journal, date & volume: PLoS ONE, 2013 , 8, e79326

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/24223927

Abstract
Recurrent interactions between neurons in the visual cortex are crucial for the integration of image elements into coherent objects, such as in figure-ground segregation of textured images. Blocking N-methyl-D-aspartate (NMDA) receptors in monkeys can abolish neural signals related to figure-ground segregation and feature integration. However, it is unknown whether this also affects perceptual integration itself. Therefore, we tested whether ketamine, a non-competitive NMDA receptor antagonist, reduces feature integration in humans. We administered a subanesthetic dose of ketamine to healthy subjects who performed a texture discrimination task in a placebo-controlled double blind within-subject design. We found that ketamine significantly impaired performance on the texture discrimination task compared to the placebo condition, while performance on a control fixation task was much less impaired. This effect is not merely due to task difficulty or a difference in sedation levels. We are the first to show a behavioral effect on feature integration by manipulating the NMDA receptor in humans.