Visual Response Properties of Neurons in the Parahippocampal Cortex of Monkeys

2003 ◽  
Vol 90 (2) ◽  
pp. 876-886 ◽  
Author(s):  
Nobuya Sato ◽  
Katsuki Nakamura

We examined visual response properties of single neurons in the parahippocampal (PH) cortex of alert monkeys using various visual stimuli (bars, geometrical shapes such as a circle, and images such as a human face) while the monkey fixated a spot for a juice reward. Of the investigated PH neurons 104 of 359 (29%) were found to be visually responsive. The investigation was focused on spatial and object aspects of visual processing. We investigated a visual receptive field (RF) property and a direction selectivity for a moving bar with respect to spatial processing. For half of these PH neurons (53%), the optimal stimulus position, where a visual stimulus elicited the maximal response, located peripherally, that is, with an eccentricity of more than 10 deg. More than 20% of these PH neurons had an RF that does not include the center of gaze. There were neurons in the PH cortex that appeared to convey motion signals. In addition, some PH neurons showed eye-position–dependent activity. With respect to object processing, we investigated selectivities for images, geographical shapes, orientations of a bar, and colors. For comparison purposes, we also examined responses of perirhinal (PR) neurons. PH neurons showed selective responses to these stimuli, but PR neurons were found to be more selective for images than PH neurons. These results suggest that the PH cortex is involved in both spatial and object processing, but less involved than the PR cortex in processing of complex images.

2019 ◽  
Author(s):  
Kyle R. Jenks ◽  
Jason D. Shepherd

ABSTRACTThe normal development of neuronal circuits requires both hard-wired gene expression and experience. Sensory processing, such as vision, is especially sensitive to perturbations in experience. However, the exact contribution of experience to neuronal visual response properties and binocular vision remains unknown. To determine how visual response properties developin vivo, we used single cell resolution two-photon calcium imaging of mouse binocular visual cortex at multiple time-points after eye opening. Few neurons are binocularly responsive immediately after eye opening and respond solely to either the contralateral or ipsilateral eye. Binocular neurons emerge during development, which requires visual experience, and show specific tuning of visual response properties. As binocular neurons emerge, activity between the two eyes becomes more correlated in the neuropil. Since experience-dependent plasticity requires the expression of activity-dependent genes, we determined whether the plasticity geneArcmediates the development of normal visual response properties. Surprisingly, rather than mirroring the effects of visual deprivation, mice that lackArcshow increased numbers of binocular neurons during development. Strikingly, removingArcin adult binocular visual cortex increases the numbers of binocular neurons and recapitulates the developmental phenotype, suggesting cortical circuits that mediate visual processing require ongoing experience-dependent plasticity. Thus, experience is critical for the normal development and maintenance of circuits required to process binocular vision.


1989 ◽  
Vol 3 (3) ◽  
pp. 249-265 ◽  
Author(s):  
Helen Sherk

AbstractThe existence of multiple areas of extrastriate visual cortex raises the question of how the response properties of each area are derived from its visual input. This question was investigated for one such area in the cat, referred to here as the Clare-Bishop area (Hubel & Wiesel, 1969); it is the region of lateral suprasylvian cortex that receives input from area 17. A novel approach was used, in which kainic acid was injected locally into the Clare-Bishop area, making it possible to record directly from afferent inputs.The response properties of the great majority of a sample of 424 presumed afferents resembled cells in areas 17 and 18. Thus, a systematic comparison was made with cells from area 17's upper layers, the source of its projection to the Clare-Bishop area (Gilbert & Kelly, 1975), to see whether these afferents had distinctive properties that might distinguish them from cells projecting to areas 18 or 19. Some differences did emerge: (1) The smallest receptive fields typical of area 17 were relatively scarce among afferents. (2) Direction-selective afferents were more abundant than were such cells in area 17. (3) End-stopped afferents were extremely rare, although end-stopped cells were common in area 17's upper layers.Despite these differences, afferents were far more similar in their properties to cells in areas 17 and 18 than to cells in the Clare-Bishop area. Compared to the latter, afferents showed major discrepancies in receptive-field size, in direction selectivity, in end-stopping, and in ocular dominance distribution. These differences seem most likely to stem from circuitry intrinsic to the Clare-Bishop area.


2002 ◽  
Vol 357 (1428) ◽  
pp. 1729-1737 ◽  
Author(s):  
W. Martin Usrey

Although the visual response properties of neurons along the retinogeniculocortical pathway have been studied for decades, relatively few studies have examined how individual neurons along the pathway communicate with each other. Recent studies in the cat ( Felis domestica ) now show that the strength of these connections is very dynamic and spike timing plays an important part in determining whether action potentials will be transferred from pre– to postsynaptic cells. This review explores recent progress in our understanding of what role spike timing has in establishing different patterns of geniculate activity and how these patterns ultimately drive the cortex.


2017 ◽  
Vol 117 (2) ◽  
pp. 566-581 ◽  
Author(s):  
James C. Dooley ◽  
Michaela S. Donaldson ◽  
Leah A. Krubitzer

The functional organization of the primary visual area (V1) and the importance of sensory experience in its normal development have been well documented in eutherian mammals. However, very few studies have investigated the response properties of V1 neurons in another large class of mammals, or whether sensory experience plays a role in shaping their response properties. Thus we reared opossums ( Monodelphis domestica) in normal and vertically striped cages until they reached adulthood. They were then anesthetized using urethane, and electrophysiological techniques were used to examine neuronal responses to different orientations, spatial and temporal frequencies, and contrast levels. For normal opossums, we observed responses to the temporal and spatial characteristics of the stimulus to be similar to those described in small, nocturnal, eutherian mammals such as rats and mice; neurons in V1 responded maximally to stimuli at 0.09 cycles per degree and 2.12 cycles per second. Unlike other eutherians, but similar to other marsupials investigated, only 40% of the neurons were orientation selective. In stripe-reared animals, neurons were significantly more likely to respond to vertical stimuli at a wider range of spatial frequencies, and were more sensitive to gratings at lower contrast values compared with normal animals. These results are the first to demonstrate experience-dependent plasticity in the visual system of a marsupial species. Thus the ability of cortical neurons to alter their properties based on the dynamics of the visual environment predates the emergence of eutherian mammals and was likely present in our earliest mammalian ancestors.NEW & NOTEWORTHY These results are the first description of visual response properties of the most commonly studied marsupial model organism, the short-tailed opossum ( Monodelphis domestica). Further, these results are the first to demonstrate experience-dependent plasticity in the visual system of a marsupial species. Thus the ability of cortical neurons to alter their properties based on the dynamics of the visual environment predates the emergence of eutherian mammals and was likely present in our earliest mammalian ancestors.


2020 ◽  
Vol 30 (15) ◽  
pp. R897-R903 ◽  
Author(s):  
Rune Rasmussen ◽  
Keisuke Yonehara

1981 ◽  
Vol 45 (3) ◽  
pp. 397-416 ◽  
Author(s):  
J. F. Baker ◽  
S. E. Petersen ◽  
W. T. Newsome ◽  
J. M. Allman

1. The response properties of 354 single neurons in the medial (M), dorsomedial (DM), dorsolateral (DL), and middle temporal (MT) visual areas were studied quantitatively with bar, spot, and random-dot stimuli in chronically implanted owl monkeys with fixed gaze. 2. A directionality index was computed to compare the responses to stimuli in the optimal direction with the responses to the opposing direction of movement. The greater the difference between opposing directions, the higher the index. MT cells had much higher direction indices to moving bars than cells in DL, DM, and M. 3. A tuning index was computed for each cell to compare the responses to bars moving in the optimal direction, or flashed in the optimal orientation, with the responses in other directions or orientations within +/- 90 degrees. Cells in all four areas were more sharply tuned to the orientation of stationary flashed bars than to moving bars, although a few cells (9/92( were unresponsive in the absence of movement. DM cells tended to be more sharply tuned to moving bars than cells in the other areas. 4. Directionality in DM, DL, and MT was relatively unaffected by the use of single-spot stimuli instead of bars; tuning in all four areas was broader to spots than bars. 5. Moving arrays of randomly spaced spots were more strongly excitatory than bar stimuli for many neurons in MT (16/31 cells). These random-dot stimuli were also effective in M, but evoked no response or weak responses from most cells in DM and DL. 6. The best velocities of movement were usually in the range of 10-100 degrees/s, although a few cells (22/227), primarily in MT (14/69 cells), preferred higher velocities. 7. Receptive fields of neurons in all four areas were much larger than striate receptive fields. Eccentricity was positively correlated with receptive-field size (r = 0.62), but was not correlated with directionality index, tuning index, or best velocity. 8. The results support the hypothesis that there are specializations of function among the cortical visual areas.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Rose Bruffaerts ◽  
◽  
Lorraine K. Tyler ◽  
Meredith Shafto ◽  
Kamen A. Tsvetanov ◽  
...  

Abstract Making sense of the external world is vital for multiple domains of cognition, and so it is crucial that object recognition is maintained across the lifespan. We investigated age differences in perceptual and conceptual processing of visual objects in a population-derived sample of 85 healthy adults (24–87 years old) by relating measures of object processing to cognition across the lifespan. Magnetoencephalography (MEG) was recorded during a picture naming task to provide a direct measure of neural activity, that is not confounded by age-related vascular changes. Multiple linear regression was used to estimate neural responsivity for each individual, namely the capacity to represent visual or semantic information relating to the pictures. We find that the capacity to represent semantic information is linked to higher naming accuracy, a measure of task-specific performance. In mature adults, the capacity to represent semantic information also correlated with higher levels of fluid intelligence, reflecting domain-general performance. In contrast, the latency of visual processing did not relate to measures of cognition. These results indicate that neural responsivity measures relate to naming accuracy and fluid intelligence. We propose that maintaining neural responsivity in older age confers benefits in task-related and domain-general cognitive processes, supporting the brain maintenance view of healthy cognitive ageing.


2005 ◽  
Vol 94 (2) ◽  
pp. 1336-1345 ◽  
Author(s):  
Bartlett D. Moore ◽  
Henry J. Alitto ◽  
W. Martin Usrey

The activity of neurons in primary visual cortex is influenced by the orientation, contrast, and temporal frequency of a visual stimulus. This raises the question of how these stimulus properties interact to shape neuronal responses. While past studies have shown that the bandwidth of orientation tuning is invariant to stimulus contrast, the influence of temporal frequency on orientation-tuning bandwidth is unknown. Here, we investigate the influence of temporal frequency on orientation tuning and direction selectivity in area 17 of ferret visual cortex. For both simple cells and complex cells, measures of orientation-tuning bandwidth (half-width at half-maximum response) are ∼20–25° across a wide range of temporal frequencies. Thus cortical neurons display temporal-frequency invariant orientation tuning. In contrast, direction selectivity is typically reduced, and occasionally reverses, at nonpreferred temporal frequencies. These results show that the mechanisms contributing to the generation of orientation tuning and direction selectivity are differentially affected by the temporal frequency of a visual stimulus and support the notion that stability of orientation tuning is an important aspect of visual processing.


2020 ◽  
Vol 6 (1) ◽  
pp. 335-362
Author(s):  
Tatiana Pasternak ◽  
Duje Tadin

Psychophysical and neurophysiological studies of responses to visual motion have converged on a consistent set of general principles that characterize visual processing of motion information. Both types of approaches have shown that the direction and speed of target motion are among the most important encoded stimulus properties, revealing many parallels between psychophysical and physiological responses to motion. Motivated by these parallels, this review focuses largely on more direct links between the key feature of the neuronal response to motion, direction selectivity, and its utilization in memory-guided perceptual decisions. These links were established during neuronal recordings in monkeys performing direction discriminations, but also by examining perceptual effects of widespread elimination of cortical direction selectivity produced by motion deprivation during development. Other approaches, such as microstimulation and lesions, have documented the importance of direction-selective activity in the areas that are active during memory-guided direction comparisons, area MT and the prefrontal cortex, revealing their likely interactions during behavioral tasks.


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