scholarly journals Variability of the relative preference for stimulus orientation and direction of movement in some units of the cat visual cortex (areas 17 and 18).

1975 ◽  
Vol 245 (2) ◽  
pp. 305-324 ◽  
Author(s):  
I M Donaldson ◽  
J R Nash
Keyword(s):  
Visual Cortex ◽  
Stimulus Orientation ◽  
Relative Preference ◽  
Cat Visual Cortex ◽  
Direction Of Movement ◽  
Areas 17 And 18

scholarly journals Laminar processing of stimulus orientation in cat visual cortex

2002 ◽  
Vol 540 (1) ◽  
pp. 321-333 ◽  
Author(s):  
Luis M. Martinez ◽  
José‐Manuel Alonso ◽  
R. Clay Reid ◽  
Judith A. Hirsch
Keyword(s):  
Visual Cortex ◽  
Stimulus Orientation ◽  
Cat Visual Cortex

Temporal-frequency tuning of direction selectivity in cat visual cortex

1992 ◽  
Vol 8 (4) ◽  
pp. 365-372 ◽  
Author(s):  
Alan B. Saul ◽  
Allen L. Humphrey
Keyword(s):  
Visual Cortex ◽  
Frequency Tuning ◽  
Temporal Frequency ◽  
Direction Selectivity ◽  
Half Cycle ◽  
Low Frequencies ◽  
Preferred Direction ◽  
Cat Visual Cortex ◽  
Cortical Responses ◽  
Areas 17 And 18

AbstractResponses of 71 cells in areas 17 and 18 of the cat visual cortex were recorded extracellularly while stimulating with gratings drifting in each direction across the receptive field at a series of temporal frequencies. Direction selectivity was most prominent at temporal frequencies of 1–2 Hz. In about 20% of the total population, the response in the nonpreferred direction increased at temporal frequencies of around 4 Hz and direction selectivity was diminished or lost. In a few cells the preferred direction reversed.One consequence of this behavior was a tendency for the preferred direction to have lower optimal temporal frequencies than the nonpreferred direction. Across the population, the preferred direction was tuned almost an octave lower. In spite of this, temporal resolution was similar in the two directions. It appeared that responses in the nonpreferred direction were suppressed at low frequencies, then recovered at higher frequencies.This phenomenon might reflect the convergence in visual cortex of lagged and nonlagged inputs from the lateral geniculate nucleus. These afferents fire about a quarter-cycle apart (i.e. are in temporal quadrature) at low temporal frequencies, but their phase difference increases to a half-cycle by about 4 Hz. Such timing differences could underlie the prevalence of direction-selective cortical responses at 1 and 2 Hz and the loss of direction selectivity in many cells by 4 or 8 Hz.

Geniculate input to cat visual cortex: a comparison of area 19 with areas 17 and 18

1980 ◽  
Vol 44 (4) ◽  
pp. 804-826 ◽  
Author(s):  
B. Dreher ◽  
A. G. Leventhal ◽  
P. T. Hale
Keyword(s):  
Visual Cortex ◽  
Area 19 ◽  
Cat Visual Cortex ◽  
Areas 17 And 18

Nonlinearity of spatial summation in simple cells of areas 17 and 18 of cat visual cortex

1991 ◽  
Vol 66 (5) ◽  
pp. 1667-1679 ◽  
Author(s):  
D. Ferster ◽  
B. Jagadeesh
Keyword(s):  
Visual Cortex ◽  
Spatial Frequency ◽  
Spatial Summation ◽  
Area 17 ◽  
Simple Cells ◽  
Area 18 ◽  
Cat Visual Cortex ◽  
Spatial Frequencies ◽  
Areas 17 And 18 ◽  
Y Cells

1. Nonlinearity of spatial summation in areas 17 and 18 of cat visual cortex was compared with the type of spatial nonlinearity that differentiates X and Y cells in the lateral geniculate nucleus (LGN) and retina. The comparisons were made to examine to what extent the information from X and Y cells may remain separated in higher visual centers. 2. Responses of simple cells in areas 17 and 18 were recorded while stationary, optimally oriented sinewave gratings were sinusoidally modulated within the receptive field of the cell. Both the spatial frequency and spatial phase of the stimulus were varied. 3. Y cells in the retina and LGN are defined by the presence of a specific form of spatial nonlinearity. When tested with contrast-modulated sinewave gratings of spatial frequencies about three-fold greater than the optimal, their responses are dominated by a frequency-doubled component. The amplitude of the frequency-doubled component is not dependent on the spatial phase of the stimulus. 4. Many simple cells in the cortex showed a form of spatial nonlinearity similar to the defining nonlinearity found in retinal and geniculate Y cells. A frequency-doubled response dominated at spatial frequencies more than threefold greater than the optimal spatial frequency. When this response was present, it was phase independent. 5. More than 50% of the simple cells in area 18 showed the Y-like spatial nonlinearity. Fewer than 10% of the simple cells in area 17 showed the Y-like spatial nonlinearity. 6. The virtual absence of Y-like nonlinearity in area 17 and its relative abundance in area 18 suggest that the functional separation between the parallel X and Y pathways remains distinct within areas 17 and 18 of cat visual cortex.

scholarly journals Prediction of Orientation Selectivity from Receptive Field Architecture in Simple Cells of Cat Visual Cortex

Neuron ◽  
2001 ◽  
Vol 30 (1) ◽  
pp. 263-274 ◽  
Author(s):  
Ilan Lampl ◽  
Jeffrey S. Anderson ◽  
Deda C. Gillespie ◽  
David Ferster
Keyword(s):  
Visual Cortex ◽  
Receptive Field ◽  
Orientation Selectivity ◽  
Simple Cells ◽  
Cat Visual Cortex
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