Purchase this article with an account.
Robert A. Frazor, Valerio Mante, Vincent Bonin, Matteo Carandini; Dynamics of spatial frequency tuning in lateral geniculate nucleus. Journal of Vision 2005;5(8):428. doi: 10.1167/5.8.428.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Neurons in primary visual cortex (V1) exhibit changes in spatial frequency tuning through time [1, 2]: a neuron's preference shifts from low frequencies early in the response to higher frequencies later in the response. This shift is accompanied by a narrowing of tuning bandwidth . It has been proposed  that such phenomena might originate in Lateral Geniculate Nucleus (LGN). LGN neurons have center-surround receptive fields with the response of the surround delayed relative to that of the center. If neurons respond linearly, spatial frequency tuning is expected to be low-pass early on in the response, and become band-pass only later. We tested this hypothesis by measuring spatial frequency tuning dynamics in 147 LGN neurons in anesthetized, paralyzed cats using reverse correlation in the spatial frequency domain . We found that the preferred spatial frequency typically shifts from lower to higher frequencies through time. The median shift is ∼0.75 octaves over a time period of 40 ms, slightly smaller than the ∼1 octave over 30 ms observed in V1 . Furthermore, the tuning bandwidth of the neurons typically narrows over this same period: the median narrowing of tuning is ∼0.2 octaves. In many cases, the preferred tuning shifts back towards lower spatial frequencies even later in the response, because the receptive field surround alone is contributing to the response. Thus, the dynamics of spatial frequency tuning observed in LGN may contribute to those seen in V1 but alone may be insufficient to explain them.
. Ringach Bredfeldt. J Neurosci., 2002
. Albrecht Frazor. J Neurophysiol. 2004
. Peterson Allen Freeman. Soc Neurosci Abs, 2004
This PDF is available to Subscribers Only