Effects of long-term potentiation in the human visual cortex: a functional magnetic resonance imaging study.
Applying functional magnetic resonance imaging techniques, hemodynamic responses elicited by slowly flashing checkerboards (0.25 Hz) were measured both before and after a block of rapidly presented checkerboards (9 Hz -- a 'photic tetanus') was delivered. It has been shown previously, using electroencephalography, that this photic tetanus potentiates components of the visual-evoked potential. In the present study, hemodynamic responses in the extrastriate visual cortex were significantly increased to checkerboards presented at a low frequency after the administration of the photic tetanus. These results support the idea that long-term potentiation can be demonstrated non-invasively within the human visual cortex and provide evidence that the plastic changes are localized within the secondary visual cortex.
Clapp
Wesley C
WC
Research Centre for Cognitive Neuroscience, University of Auckland, Auckland, New Zealand. w.clapp@auckland.ac.nz
Zaehle
Tino
T
Lutz
Kai
K
Marcar
Val L
VL
Kirk
Ian J
IJ
Hamm
Jeff P
JP
Teyler
Tim J
TJ
Corballis
Michael C
MC
Jancke
Lutz
L
D001931:Brain Mapping; D005074:Evoked Potentials, Visual / Q000502:physiology; D006801:Humans; D017774:Long-Term Potentiation / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D010775:Photic Stimulation; D014793:Visual Cortex / Q000502:physiology*