scholarly journals Two Types of Receptive Field Dynamics in Area V4 at the Time of Eye Movements?

2017 ◽  
Vol 11 ◽  
Author(s):  
Till S. Hartmann ◽  
Marc Zirnsak ◽  
Michael Marquis ◽  
Fred H. Hamker ◽  
Tirin Moore
Keyword(s):  
Eye Movements ◽  
Receptive Field ◽  
Area V4

scholarly journals Rhythmic neural spiking and attentional sampling arising from cortical receptive field interactions

2018 ◽  
Author(s):  
Ricardo Kienitz ◽  
Joscha T. Schmiedt ◽  
Katharine A. Shapcott ◽  
Kleopatra Kouroupaki ◽  
Richard C. Saunders ◽  
...  
Keyword(s):  
Eye Movements ◽  
Receptive Field ◽  
Spatial Attention ◽  
Receptive Fields ◽  
Reaction Times ◽  
List Type ◽  
Attention Task ◽  
Area V4 ◽  
Fixational Eye Movements ◽  
Visual Cortical Area

SummaryGrowing evidence suggests that distributed spatial attention may invoke theta (3-9 Hz) rhythmic sampling processes. The neuronal basis of such attentional sampling is however not fully understood. Here we show using array recordings in visual cortical area V4 of two awake macaques that presenting separate visual stimuli to the excitatory center and suppressive surround of neuronal receptive fields elicits rhythmic multi-unit activity (MUA) at 3-6 Hz. This neuronal rhythm did not depend on small fixational eye movements. In the context of a distributed spatial attention task, during which the monkeys detected a spatially and temporally uncertain target, reaction times (RT) exhibited similar rhythmic fluctuations. RTs were fast or slow depending on the target occurrence during high or low MUA, resulting in rhythmic MUA-RT cross-correlations at at theta frequencies. These findings suggest that theta-rhythmic neuronal activity arises from competitive receptive field interactions and that this rhythm may subserve attentional sampling.HighlightsCenter-surround interactions induce theta-rhythmic MUA of visual cortex neuronsThe MUA rhythm does not depend on small fixational eye movementsReaction time fluctuations lock to the neuronal rhythm under distributed attention

scholarly journals Attention operates uniformly throughout the classical receptive field and the surround

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Bram-Ernst Verhoef ◽  
John HR Maunsell
Keyword(s):  
Receptive Field ◽  
Cortical Neurons ◽  
Receptive Fields ◽  
Spatial Summation ◽  
Field Structure ◽  
Neuronal Responses ◽  
Large Variability ◽  
Area V4 ◽  
Classical Receptive Field ◽  
Spatially Varying

Shifting attention among visual stimuli at different locations modulates neuronal responses in heterogeneous ways, depending on where those stimuli lie within the receptive fields of neurons. Yet how attention interacts with the receptive-field structure of cortical neurons remains unclear. We measured neuronal responses in area V4 while monkeys shifted their attention among stimuli placed in different locations within and around neuronal receptive fields. We found that attention interacts uniformly with the spatially-varying excitation and suppression associated with the receptive field. This interaction explained the large variability in attention modulation across neurons, and a non-additive relationship among stimulus selectivity, stimulus-induced suppression and attention modulation that has not been previously described. A spatially-tuned normalization model precisely accounted for all observed attention modulations and for the spatial summation properties of neurons. These results provide a unified account of spatial summation and attention-related modulation across both the classical receptive field and the surround.

Eye Position Compensation Improves Estimates of Response Magnitude and Receptive Field Geometry in Alert Monkeys

2007 ◽  
Vol 97 (5) ◽  
pp. 3439-3448 ◽  
Author(s):  
Yamei Tang ◽  
Alan Saul ◽  
Moshe Gur ◽  
Stephanie Goei ◽  
Elsie Wong ◽  
...  
Keyword(s):  
Eye Movements ◽  
Receptive Field ◽  
Receptive Fields ◽  
Eye Position ◽  
Stimulus Position ◽  
Fixational Eye Movements ◽  
Field Geometry ◽  
Receptive Field Subregions ◽  
Movement Compensation ◽  
Definition Of

Studies of visual function in behaving subjects require that stimuli be positioned reliably on the retina in the presence of eye movements. Fixational eye movements scatter stimuli about the retina, inflating estimates of receptive field dimensions, reducing estimates of peak responses, and blurring maps of receptive field subregions. Scleral search coils are frequently used to measure eye position, but their utility for correcting the effects of fixational eye movements on receptive field maps has been questioned. Using eye coils sutured to the sclera and preamplifiers configured to minimize cable artifacts, we reexamined this issue in two rhesus monkeys. During repeated fixation trials, the eye position signal was used to adjust the stimulus position, compensating for eye movements and correcting the stimulus position to place it at the desired location on the retina. Estimates of response magnitudes and receptive field characteristics in V1 and in LGN were obtained in both compensated and uncompensated conditions. Receptive fields were narrower, with steeper borders, and response amplitudes were higher when eye movement compensation was used. In sum, compensating for eye movements facilitated more precise definition of the receptive field. We also monitored horizontal vergence over long sequences of fixation trials and found the variability to be low, as expected for this precise behavior. Our results imply that eye coil signals can be highly accurate and useful for optimizing visual physiology when rigorous precautions are observed.

scholarly journals Changes in the Response Rate and Response Variability of Area V4 Neurons During the Preparation of Saccadic Eye Movements

2010 ◽  
Vol 103 (3) ◽  
pp. 1171-1178 ◽  
Author(s):  
Nicholas A. Steinmetz ◽  
Tirin Moore
Keyword(s):  
Eye Movements ◽  
Reaction Time ◽  
Firing Rate ◽  
Response Rate ◽  
Saccadic Eye Movements ◽  
Response Variability ◽  
Area V4 ◽  
The Mean ◽  
V4 Neurons ◽  
Saccade Preparation

The visually driven responses of macaque area V4 neurons are modulated during the preparation of saccadic eye movements, but the relationship between presaccadic modulation in area V4 and saccade preparation is poorly understood. Recent neurophysiological studies suggest that the variability across trials of spiking responses provides a more reliable signature of motor preparation than mean firing rate across trials. We compared the dynamics of the response rate and the variability in the rate across trials for area V4 neurons during the preparation of visually guided saccades. As in previous reports, we found that the mean firing rate of V4 neurons was enhanced when saccades were prepared to stimuli within a neuron's receptive field (RF) in comparison with saccades to a non-RF location. Further, we found robust decreases in response variability prior to saccades and found that these decreases predicted saccadic reaction times for saccades both to RF and non-RF stimuli. Importantly, response variability predicted reaction time whether or not there were any accompanying changes in mean firing rate. In addition to predicting saccade direction, the mean firing rate could also predict reaction time, but only for saccades directed to the RF stimuli. These results demonstrate that response variability of area V4 neurons, like mean response rate, provides a signature of saccade preparation. However, the two signatures reflect complementary aspects of that preparation.

scholarly journals GABA inactivation of area V4 changes receptive-field properties of V2 neurons in Cebus monkeys

2012 ◽  
Vol 235 (2) ◽  
pp. 553-562 ◽  
Author(s):  
Ana Karla Jansen-Amorim ◽  
Mario Fiorani ◽  
Ricardo Gattass
Keyword(s):  
Receptive Field ◽  
Area V4 ◽  
Receptive Field Properties ◽  
Cebus Monkeys

scholarly journals Receptive field focus of visual area V4 neurons determines responses to illusory surfaces

2013 ◽  
Vol 110 (42) ◽  
pp. 17095-17100 ◽  
Author(s):  
M. A. Cox ◽  
M. C. Schmid ◽  
A. J. Peters ◽  
R. C. Saunders ◽  
D. A. Leopold ◽  
...  
Keyword(s):  
Receptive Field ◽  
Visual Area ◽  
Area V4 ◽  
Visual Area V4 ◽  
V4 Neurons

scholarly journals Suppression without inhibition: A novel mechanism in the retina accounts for saccadic suppression

2020 ◽  
Author(s):  
Saad Idrees ◽  
Matthias-Philipp Baumann ◽  
Maria M. Korympidou ◽  
Timm Schubert ◽  
Alexandra Kling ◽  
...  
Keyword(s):  
Eye Movements ◽  
Visual Perception ◽  
Receptive Field ◽  
Calcium Imaging ◽  
Ganglion Cells ◽  
Saccadic Eye Movements ◽  
Visual Sensitivity ◽  
Saccadic Suppression ◽  
Retinal Processing ◽  
Retinal Pathways

AbstractVisual perception remains stable across saccadic eye movements, despite the concurrent strongly disruptive visual flow. This stability is partially associated with a reduction in visual sensitivity, known as saccadic suppression, which already starts in the retina with reduced ganglion cell sensitivity. However, the retinal circuit mechanisms giving rise to such suppression remain unknown. Here, we describe these mechanisms using electrophysiology in mouse, pig, and macaque retina, 2-photon calcium imaging, computational modeling, and human psychophysics. We find a novel retinal processing motif underlying retinal saccadic suppression, “dynamic reversal suppression”, which is triggered by sequential stimuli containing contrast reversals. This motif does not involve inhibition but relies on nonlinear transformation of the inherently slow responses of cone photoreceptors by downstream retinal pathways. Two further components of suppression are present in ON ganglion cells and originate in the cells’ receptive field surround, highlighting a novel disparity between ON and OFF ganglion cells. Our results are relevant for any sequential stimulation encountered frequently in naturalistic scenarios.

Focal attention produces spatially selective processing in visual cortical areas V1, V2, and V4 in the presence of competing stimuli

1993 ◽  
Vol 70 (3) ◽  
pp. 909-919 ◽  
Author(s):  
B. C. Motter
Keyword(s):  
Receptive Field ◽  
Stimulus Presentation ◽  
Spatial Location ◽  
Differential Sensitivity ◽  
Orientation Tuning ◽  
Area V4 ◽  
Focal Attention ◽  
V4 Neurons ◽  
Visual Cortical ◽  
Competing Stimuli

1. The activity of single neurons was recorded in Macaca mulatta monkeys while they performed tasks requiring them to select a cued stimulus from an array of three to eight stimuli and report the orientation of that stimulus. Stimuli were presented in a circular array centered on the fixation target and scaled to place a single stimulus element within the receptive field of the neuron under study. The timing of the cuing event permitted the directing of visual attention to the spatial location of the correct stimulus before its presentation. 2. The effects of focal attention were examined in cortical visual areas V1, V2, and V4, where a total of 672 neurons were isolated with complete studies obtained for 94 V1, 74 V2, and 74 V4 neurons with receptive-field center eccentricities in the range 1.8-8 degrees. Under certain conditions, directed focal attention results in changes in the response of V1, V2, and V4 neurons to otherwise identical stimuli at spatially specific locations. 3. More than one-third of the neurons in each area displayed differential sensitivity when attention was directed toward versus away from the spatial location of the receptive field just before and during stimulus presentation. Both relative increases and decreases in neural activity were observed in association with attention directed at receptive-field stimuli. 4. The presence of multiple competing stimuli in the visual field was a major factor determining the presence or absence of differential sensitivity. About two-thirds of the neurons that were differentially sensitive to the attending condition in the presence of competing stimuli were not differentially sensitive when single stimuli were presented in control studies. For V1 and V2 neurons the presence of only a few (3-4) competing stimuli was sufficient for a majority of the neurons studied; a majority of the V4 neurons required six to eight stimuli in the array before significant differences between attending conditions occurred. 5. For V1 and V2 neurons the neuronal sensitivity differences between attending conditions were observed primarily at or near the peak of the orientation tuning sensitivity for each neuron; the differences were evident over a broader range of orientations in V4 neurons. 6. In conclusion, neural correlates of focal attentive processes can be observed in visual cortical processing in areas V1 and V2 as well as area V4 under conditions that require stimulus feature analysis and selective spatial processing within a field of competing stimuli.(ABSTRACT TRUNCATED AT 400 WORDS)

Comparison of neuronal selectivity for stimulus speed, length, and contrast in the prestriate visual cortical areas V4 and MT of the macaque monkey

1994 ◽  
Vol 71 (6) ◽  
pp. 2269-2280 ◽  
Author(s):  
K. Cheng ◽  
T. Hasegawa ◽  
K. S. Saleem ◽  
K. Tanaka
Keyword(s):  
Receptive Field ◽  
Luminance Contrast ◽  
Macaque Monkey ◽  
Stimulus Motion ◽  
Temporal Area ◽  
Area V4 ◽  
Optimal Speed ◽  
Stimulus Speed ◽  
Stimulus Length ◽  
Visual Cortical

1. Prestriate area V4 and the middle temporal area (MT) compose the first stage in which the ventral and dorsal visual cortical pathways are segregated. To better known the functional dichotomy between the two pathways at this level, we recorded cell responses from V4 and MT using anesthetized, immobilized macaque monkeys and compared the selectivity for speed of stimulus motion and stimulus length and the sensitivity to luminance contrast between the two areas. 2. V4 cells were as selective as MT cells for speed. The sharpness of tuning was not different between the two populations. The optimal speed varied widely in both areas, but both of the two distributions showed peaks at 32 degrees/s. 3. V4 and MT cells were similar in that about one-half of the cells (45% in V4 and 48% in MT) showed inhibition by long (16 degrees) bars. However, V4 cells preferred stimuli whose lengths were distributed around the lengths of the receptive field, whereas an overwhelming majority of MT cells preferred stimuli whose lengths were much shorter than the lengths of the receptive field. 4. The cutoff contrast at which one-half the maximum response was elicited was distributed widely in both areas, and the two distributions considerably overlapped. MT cells as a whole, however, were slightly more sensitive to the luminance contrast than V4 cells. 5. There was a tendency toward local clustering for cells with similar speed preferences in MT but not in V4. Pairs of MT cells recorded within 400 microns had smaller difference in the optimal speed than that of cell pairs taken randomly from the whole sample of MT cells.

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