Periodic-pattern-selective cells in monkey visual cortex

Abstract

To study the visual processing of periodic and aperiodic patterns, we have analyzed neuronal responses in areas V1 and V2 of the visual cortex of alert monkeys during behaviorally induced fixation of gaze. Receptive field eccentricities ranged between 0.5 degrees and 4 degrees. We found cells that responded vigorously to gratings, but weakly or not all to bars and edges. In some cells the aperiodic stimuli even reduced the activity below the spontaneous level. The distribution of a bar-grating response index indicated a discrete population of “grating cells” characterized by more than 10-fold superiority of gratings. We estimated that these cells have a frequency of 4% in V1 and 1.6% in V2, and that about 4 million grafting cells of V1 subserve the central 4 degrees of vision. The converse, cells that responded to isolated bars but not to gratings of any periodicity, was also observed. The grating cells of V1 were mostly (23 of 26) found in layers 2, 3, and 4B. They preferred spatial frequencies between 2.6 and 19 cycles/degree (median, 9.3), with tuning widths at half-amplitude between 0.4 and 1.4 octaves (median, 1.0). Their tunings were narrower, and their preferred frequencies higher, than those of other cells on average. Grating cells were also narrowly tuned for orientation. Those of V2 were similarly selective. The responses of grating cells depended critically on the number of cycles of the gratings. With square waves of optimum periodicity responses required a minimum of 2–6 grating cycles and leveled off at 4–14 (median, 7.5). The corresponding receptive field widths were 0.34–2.4 degrees (median, 0.78 degrees) for V1 and 0.72–2.4 degrees (median, 1.4 degrees) for V2. Grating cells typically gave unmodulated responses to drifting gratings, were unselective for direction of motion, and were strongly activated also by stationary gratings. Half of those of V1 were monocular, the others binocular, some showing strong binocular facilitation and disparity sensitivity. Length summation was usually monotonic, but strong end- inhibition was also observed. In contrast to other cells, grating cells were not activated by harmonic components. Spatial-frequency response curves for sine-wave, square-wave, and line gratings were similar. Square-wave gratings of one-third the preferred frequency failed to excite the cells, while the isolated 3f component (f = the fundamental of the square wave) of these gratings evoked strong responses. In spite of the nonlinear features, grating cells had low contrast thresholds.(ABSTRACT TRUNCATED AT 400 WORDS)

Computational model of dot-pattern selective cells

“…These cells belonged to a larger group of cells that they called`texture cells'. The majority of these texture cells responded optimally to gratings, and the description of the cells fully complies with the description of the grating cells given by Von der Heydt et al (1992).…”

“…Von der Heydt et al (1991Heydt et al ( , 1992 reported on the properties of a speci®c type of orientation selective neuron in areas V1 and V2 of the visual cortex of monkeys that they called the grating cell. Similarly to other orientation selective neurons, such as simple, complex and hyper-complex cells, grating cells respond vigorously to a grating of bars of appropriate orientation, position and periodicity.…”

Motion detection, noise reduction, texture suppression, and contour enhancement by spatiotemporal Gabor filters with surround inhibition

“…1999) the majority of orientationselective cells in V1 exhibit surround inhibition that leads to suppression of responses of texture. However, there are also neurons in V1 and V2, called grating cells, that show selective responses to oriented texture (von der Heydt et al 1991(von der Heydt et al , 1992du Buf 2007,Kruizinga andPetkov 1999). Furthermore, there are cells in MT, called wide-field neurons, that prefer large moving texture fields and exhibit no surround inhibition (Allman et al 1985;Born and Tootell 1992;Raiguel et al 1995).…”

Suppression of contour perception by band-limited noise and its relation to nonclassical receptive field inhibition

“…Only in the extreme case of complete suppression will the operator respond exclusively to single bars and not respond to gratings of any periodicity. Such neurons have occasionally been encountered in neurophysiological studies (Schiller et al 1976;von der Heydt et al 1992). At the opposite end of the function continuum of orientation-selective cells, one can find the grating cells (von der Heydt et al 1992), which respond optimally to gratings and, in the extreme case of ''gratingness,'' do not respond to single bars.…”

“…2c was related to the function of a specific type of orientation-selective cell in the primary visual cortex for which the response to an optimal stimulus over the cell's classical (excitatory) receptive field (CRF) is influenced by other stimuli outside that area (Petkov and Kruizinga 1997). In contrast to other orientation-selective neurons, such as simple (Hubel and Wiesel 1968), complex (Hubel and Wiesel 1968), and grating (von der Heydt et al 1992) cells, the concerned type of neuron responds strongly to single bars (of appropriate size and orientation) over its CRF and shows reduced response when a grating is added to the surround. The behavior of such a cell was systematically studied by Blakemore and Tobin (1972).…”