Tuning for spatiotemporal frequency and speed in directionally selective neurons of macaque striate cortex. Priebe, N. J, Lisberger, S. G, & Movshon, J A. The Journal of neuroscience : the official journal of the Society for Neuroscience, 26(11):2941–50, March, 2006.
Tuning for spatiotemporal frequency and speed in directionally selective neurons of macaque striate cortex. [link]Paper  doi  abstract   bibtex   
We recorded the responses of direction-selective simple and complex cells in the primary visual cortex (V1) of anesthetized, paralyzed macaque monkeys. When studied with sine-wave gratings, almost all simple cells in V1 had responses that were separable for spatial and temporal frequency: the preferred temporal frequency did not change and preferred speed decreased as a function of the spatial frequency of the grating. As in previous recordings from the middle temporal visual area (MT), approximately one-quarter of V1 complex cells had separable responses to spatial and temporal frequency, and one-quarter were "speed tuned" in the sense that preferred speed did not change as a function of spatial frequency. Half fell between these two extremes. Reducing the contrast of the gratings caused the population of V1 complex cells to become more separable in their tuning for spatial and temporal frequency. Contrast dependence is explained by the contrast gain of the neurons, which was relatively higher for gratings that were either both of high or both of low temporal and spatial frequency. For stimuli that comprised two spatially superimposed sine-wave gratings, the preferred speeds and tuning bandwidths of V1 neurons could be predicted from the sum of the responses to the component gratings presented alone, unlike neurons in MT that showed nonlinear interactions. We conclude that spatiotemporal modulation of contrast gain creates speed tuning from separable inputs in V1 complex cells. Speed tuning in MT could be primarily inherited from V1, but processing that occurs after V1 and possibly within MT computes selective combinations of speed-tuned signals of special relevance for downstream perceptual and motor mechanisms.
@article{Priebe2006,
	title = {Tuning for spatiotemporal frequency and speed in directionally selective neurons of macaque striate cortex.},
	volume = {26},
	issn = {1529-2401},
	url = {http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2532672&tool=pmcentrez&rendertype=abstract},
	doi = {10.1523/JNEUROSCI.3936-05.2006},
	abstract = {We recorded the responses of direction-selective simple and complex cells in the primary visual cortex (V1) of anesthetized, paralyzed macaque monkeys. When studied with sine-wave gratings, almost all simple cells in V1 had responses that were separable for spatial and temporal frequency: the preferred temporal frequency did not change and preferred speed decreased as a function of the spatial frequency of the grating. As in previous recordings from the middle temporal visual area (MT), approximately one-quarter of V1 complex cells had separable responses to spatial and temporal frequency, and one-quarter were "speed tuned" in the sense that preferred speed did not change as a function of spatial frequency. Half fell between these two extremes. Reducing the contrast of the gratings caused the population of V1 complex cells to become more separable in their tuning for spatial and temporal frequency. Contrast dependence is explained by the contrast gain of the neurons, which was relatively higher for gratings that were either both of high or both of low temporal and spatial frequency. For stimuli that comprised two spatially superimposed sine-wave gratings, the preferred speeds and tuning bandwidths of V1 neurons could be predicted from the sum of the responses to the component gratings presented alone, unlike neurons in MT that showed nonlinear interactions. We conclude that spatiotemporal modulation of contrast gain creates speed tuning from separable inputs in V1 complex cells. Speed tuning in MT could be primarily inherited from V1, but processing that occurs after V1 and possibly within MT computes selective combinations of speed-tuned signals of special relevance for downstream perceptual and motor mechanisms.},
	number = {11},
	urldate = {2013-08-29},
	journal = {The Journal of neuroscience : the official journal of the Society for Neuroscience},
	author = {Priebe, Nicholas J and Lisberger, Stephen G and Movshon, J Anthony},
	month = mar,
	year = {2006},
	pmid = {16540571},
	keywords = {\#nosource, Action Potentials, Animals, Brain Mapping, Macaca fascicularis, Microelectrodes, Motion Perception, Motion Perception: physiology, Neurons, Neurons: physiology, Photic Stimulation, Retina, Retina: physiology, Temporal Lobe, Temporal Lobe: physiology, Time Perception, Time Perception: physiology, Vision, Monocular, Vision, Monocular: physiology, Visual Cortex, Visual Cortex: cytology, Visual Cortex: physiology},
	pages = {2941--50},
}

Downloads: 0