Unsupervised Natural Experience Rapidly Alters Invariant Object Representation in Visual Cortex.

Li N, Dicarlo JJ.
Science. 2008 Sep 12;321(5895):1502-1507

Object recognition is challenging because each object produces myriad retinal images. Responses of neurons from the inferior temporal cortex (IT) are selective to different objects, yet tolerant ("invariant") to changes in object position, scale, and pose. How does the brain construct this neuronal tolerance? We report a form of neuronal learning that suggests the underlying solution. Targeted alteration of the natural temporal contiguity of visual experience caused specific changes in IT position tolerance. This unsupervised temporal slowness learning (UTL) was substantial, increased with experience, and was significant in single IT neurons after just 1 hour. Together with previous theoretical work and human object perception experiments, we speculate that UTL may reflect the mechanism by which the visual stream builds and maintains tolerant object representations.

PMID: 18787171

Full text: http://www.sciencemag.org/cgi/reprint/321/5895/1502.pdf