RT Journal Article
SR Electronic
T1 Motion-Sensitive Responses in Visual Area V4 in the Absence of Primary Visual Cortex
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 18740
OP 18745
DO 10.1523/JNEUROSCI.3923-13.2013
VO 33
IS 48
A1 Michael C. Schmid
A1 Joscha T. Schmiedt
A1 Andrew J. Peters
A1 Richard C. Saunders
A1 Alexander Maier
A1 David A. Leopold
YR 2013
UL http://www.jneurosci.org/content/33/48/18740.abstract
AB Neurons in cortical ventral-stream area V4 are thought to contribute to important aspects of visual processing by integrating information from primary visual cortex (V1). However, how V4 neurons respond to visual stimulation after V1 injury remains unclear: While electrophysiological investigation of V4 neurons during reversible V1 inactivation suggests that virtually all responses are eliminated (Girard et al., 1991), fMRI in humans and monkeys with permanent lesions shows reliable V1-independent activity (Baseler et al., 1999; Goebel et al., 2001; Schmid et al., 2010). To resolve this apparent discrepancy, we longitudinally assessed neuronal functions of macaque area V4 using chronically implanted electrode arrays before and after creating a permanent aspiration lesion in V1. During the month after lesioning, we observed weak yet significant spiking activity in response to stimuli presented to the lesion-affected part of the visual field. These V1-independent responses showed sensitivity for motion and likely reflect the effect of V1-bypassing geniculate input into extrastriate areas.