Electrophysiological measures of visual suppression

In the early visual system, suppression occurs between neurons representing different stimulus properties. This includes features such as orientation (cross-orientation suppression), eye-of-origin (interocular suppression) and spatial location (surround suppression), which are thought to involve distinct anatomical pathways. We asked if these separate routes to suppression can be differentiated by their pattern of gain control on the contrast response function measured in human participants using steady-state electroencephalography. Changes in contrast gain shift the contrast response function laterally, whereas changes in response gain scale the function vertically. We used a Bayesian hierarchical model to summarise the evidence for each type of gain control. A computational meta-analysis of 16 previous studies found the most evidence for contrast gain effects with overlaid masks, but no clear evidence favouring either response gain or contrast gain for other mask types. We then conducted two new experiments, comparing suppression from four mask types (monocular and dichoptic overlay masks, and aligned and orthogonal surround masks) on responses to sine wave grating patches flickering at 5Hz. At the occipital pole, there was strong evidence for contrast gain effects in all four mask types at the first harmonic frequency (5Hz). Suppression generally became stronger at more lateral electrode sites, but there was little evidence of response gain effects. At the second harmonic frequency (10Hz) suppression was stronger overall, and involved both contrast and response gain effects. Although suppression from different mask types involves distinct anatomical pathways, gain control processes appear to serve a common purpose, which we suggest might be to suppress less reliable inputs.

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Steady-state measures of visual suppression

PLoS Computational Biology ◽

10.1371/journal.pcbi.1009507 ◽

2021 ◽

Vol 17 (10) ◽

pp. e1009507

Author(s):

Daniel H. Baker ◽

Greta Vilidaite ◽

Alex R. Wade

Keyword(s):

Steady State ◽

Response Function ◽

Second Harmonic ◽

Meta Analysis ◽

Gain Control ◽

Sine Wave ◽

Harmonic Frequency ◽

Contrast Gain ◽

Contrast Response Function ◽

Contrast Response

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Dynamic shifts of the contrast-response function

Visual Neuroscience ◽

10.1017/s0952523800012232 ◽

1997 ◽

Vol 14 (3) ◽

pp. 577-587 ◽

Cited By ~ 10

Author(s):

Jonathan D. Victor ◽

Mary M. Conte ◽

Keith P. Purpura

Keyword(s):

Gain Control ◽

Human Vision ◽

High Contrast ◽

Contrast Level ◽

Low Contrast ◽

Contrast Gain ◽

Contrast Response Function ◽

Stimuli Response ◽

Response Phase ◽

Contrast Response

AbstractWe recorded visual evoked potentials in response to square-wave contrast-reversal checkerboards undergoing a transition in the mean contrast level. Checkerboards were modulated at 4.22 Hz (8.45-Hz reversal rate). After each set of 16 cycles of reversals, stimulus contrast abruptly switched between a “high” contrast level (0.06 to 1.0) to a “low” contrast level (0.03 to 0.5). Higher contrasts attenuated responses to lower contrasts by up to a factor of 2 during the period immediately following the contrast change. Contrast-response functions derived from the initial second following a conditioning contrast shifted by a factor of 2–4 along the contrast axis. For low-contrast stimuli, response phase was an advancing function of the contrast level in the immediately preceding second. For high-contrast stimuli, response phase was independent of the prior contrast history. Steady stimulation for periods as long as 1 min produced only minor effects on response amplitude, and no detectable effects on response phase. These observations delineate the dynamics of a contrast gain control in human vision.

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Development of visual inhibitory interactions in kittens

Visual Neuroscience ◽

10.1017/s0952523800004818 ◽

1991 ◽

Vol 7 (4) ◽

pp. 321-334 ◽

Cited By ~ 5

Author(s):

M. Concetta Morrone ◽

Harriet D. Speed ◽

David C. Burr

Keyword(s):

Second Harmonic ◽

Gain Control ◽

Contrast Threshold ◽

Control Mechanisms ◽

Response Curves ◽

Contrast Gain ◽

Visual Neurones ◽

Adult Cats ◽

Contrast Response ◽

Inhibitory Interactions

AbstractThis study was designed to monitor the development of inhibitory interactions elicited in the cat visual system by oriented visual stimuli. Steady-state visual-evoked potentials (VEPs) were recorded from the scalp of 11 behaving and alert kittens while they viewed contrast-reversed sinusoidal gratings. In adult cats, the form of VEP contrast-response curves (the amplitude of second harmonic modulation as a function of stimulus contrast) was modified by superimposing a mask grating on the test. Parallel masks displaced the curves to a higher contrast region (probably via contrast gain-control mechanisms), increasing contrast threshold without affecting the slope of the curve. Orthogonal gratings, on the other hand, decrease the slope of the curve without affecting threshold (so called cross-orientation inhibition: Morrone et al., 1981). These effects are similar to those previously reported in human VEPs (Morrone & Burr, 1986; Burr & Morrone, 1987) and single cortical cat cells (Morrone et al., 1982). For young kittens of 20 days, the orthogonal mask had no effect whatsoever on the response curves, and the effect of the parallel mask was much less than for adult cats. At about 40 days, the orthogonal mask began to attenuate responses multiplicatively, and by 50 days the amount of multiplicative attenuation had reached adult levels. The effect of the parallel mask (as indicated by the increase in threshold elevation) increased gradually from 20–50 days. The results are consistent with the existence of at least two types of inhibition in cat visual neurones that develop at different rates.

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Visual Cortex Neurons of Monkeys and Cats: Temporal Dynamics of the Contrast Response Function

Journal of Neurophysiology ◽

10.1152/jn.2002.88.2.888 ◽

2002 ◽

Vol 88 (2) ◽

pp. 888-913 ◽

Cited By ~ 103

Author(s):

Duane G. Albrecht ◽

Wilson S. Geisler ◽

Robert A. Frazor ◽

Alison M. Crane

Keyword(s):

Visual Cortex ◽

Response Function ◽

Temporal Dynamics ◽

Gain Control ◽

Temporal Response ◽

Contrast Response Function ◽

Visual Cortex Neurons ◽

Contrast Normalization ◽

Single Fixation ◽

Contrast Response

Cortical neurons display two fundamental nonlinear response characteristics: contrast-set gain control (also termed contrast normalization) and response expansion (also termed half-squaring). These nonlinearities could play an important role in forming and maintaining stimulus selectivity during natural viewing, but only if they operate well within the time frame of a single fixation. To analyze the temporal dynamics of these nonlinearities, we measured the responses of individual neurons, recorded from the primary visual cortex of monkeys and cats, as a function of the contrast of transient stationary gratings that were presented for a brief interval (200 ms). We then examined 1) the temporal response profile (i.e., the post stimulus time histogram) as a function of contrast and 2) the contrast response function throughout the course of the temporal response. We found that the shape and complexity of the temporal response profile varies considerably from cell to cell. However, within a given cell, the shape remains relatively invariant as a function of contrast and appears to be simply scaled and shifted. Stated quantitatively, approximately 95% of the variation in the temporal responses as a function of contrast could be accounted for by scaling and shifting the average poststimulus time histogram. Equivalently, we found that the overall shape of the contrast response function (measured every 2 ms) remains relatively invariant from the onset through the entire temporal response. Further, the contrast-set gain control and the response expansion are fully expressed within the first 10 ms after the onset of the response. Stated quantitatively, the same, scaled Naka-Rushton equation (with the same half-saturation contrast and expansive response exponent) provides a good fit to the contrast response function from the first 10 ms through the last 10 ms of the temporal response. Based upon these measurements, it appears as though the two nonlinear properties, contrast-set gain control and response expansion, are present in full strength, virtually instantaneously, at the onset of the response. This observation suggests that response expansion and contrast-set gain control can influence the performance of visual cortex neurons very early in a single fixation, based on the contrast within that fixation. In the discussion, we consider the implications of the results within the context of 1) slower types of contrast gain control, 2) discrimination performance, 3) drifting steady-state measurements, 4) functional models that incorporate response expansion and contrast normalization, and 5) structural models of the biochemical and biophysical neural mechanisms.

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Derivation of the Visual Contrast Response Function by Maximizing Information Rate

Neural Computation ◽

10.1162/089976602317250889 ◽

2002 ◽

Vol 14 (3) ◽

pp. 527-542 ◽

Cited By ~ 12

Author(s):

Allan Gottschalk

Keyword(s):

Gain Control ◽

Information Rate ◽

Maximal Response ◽

Early Vision ◽

Contrast Gain ◽

Contrast Gain Control ◽

Ratio Equation ◽

Visual Contrast ◽

Contrast Response Function ◽

Contrast Response

A graph of neural output as a function of the logarithm of stimulus intensity often produces an S-shaped function, which is frequently modeled by the hyperbolic ratio equation. The response of neurons in early vision to stimuli of varying contrast is an important example of this. Here, the hyperbolic ratio equation with a response exponent of two is derived exactly by considering the balance between information rate and the neural costs of making that information available, where neural costs are a function of synaptic strength and spike rate. The maximal response and semisaturation constant of the neuron can be related to the stimulus ensemble and therefore shift accordingly to exhibit contrast gain control and normalization.

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Crossmodal attention alters auditory contrast sensitivity

Seeing and Perceiving ◽

10.1163/187847612x648062 ◽

2012 ◽

Vol 25 (0) ◽

pp. 177

Author(s):

Vivian Ciaramitaro ◽

Dan Jentzen

Keyword(s):

Visual Attention ◽

Contrast Sensitivity ◽

Response Function ◽

Visual Processing ◽

Visual Task ◽

Contrast Gain ◽

Crossmodal Attention ◽

Visual Contrast ◽

Contrast Response Function ◽

Contrast Response

We examined the influence of covert, endogenous, crossmodal attention on auditory contrast sensitivity in a two-interval forced-choice dual-task paradigm. Attending to a visual stimulus has been found to alter the visual contrast response function via a mechanism of contrast gain for sustained visual attention, or a combination of response gain and contrast gain for transient visual attention (Ling and Carrasco, 2006). We examined if and how auditory contrast sensitivity varied as a function of attentional load, the difficulty of a competing visual task, and how such effects compared to those found for the influences of attention on visual processing. In our paradigm, subjects listened to two sequential white noise stimuli, one of which was amplitude modulated. Subjects reported which interval contained the amplitude modulated auditory stimulus. At the same time a sequence of 5 letters was presented, in an rsvp stream at central fixation, for each interval. Subjects judged which interval contained the visual target. For a given block of trials, subjects judged which interval contained white letters (easy visual task) or, in a separate block of trials, which interval had more target letters ‘A’ (difficult visual task). We found that auditory thresholds were lower for the easy compared to the difficult visual task and that the shift in the auditory contrast response function was reminiscent of a contrast gain mechanism for visual contrast. Importantly, we found that the effects of crossmodal attention on the auditory contrast response function diminished with practice.

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Motion selectivity and the contrast-response function of simple cells in the visual cortex

Visual Neuroscience ◽

10.1017/s0952523800010336 ◽

1991 ◽

Vol 7 (6) ◽

pp. 531-546 ◽

Cited By ~ 269

Author(s):

Duane G. Albrecht ◽

Wilson S. Geisler

Keyword(s):

Visual Cortex ◽

Receptive Field ◽

Response Function ◽

Gain Control ◽

Direction Selectivity ◽

Metabolic Energy ◽

Simple Cells ◽

Contrast Response Function ◽

Spatiotemporal Receptive Field ◽

Contrast Response

AbstractThe responses of simple cells were recorded from the visual cortex of cats, as a function of the position and contrast of counterphase and drifting grating patterns, to assess whether direction selectivity can be accounted for on the basis of linear summation. The expected responses to a counterphase grating, given a strictly linear model, would be the sum of the responses to the two drifting components. The measured responses were not consistent with the linear prediction. For example, nearly all cells showed two positions where the responses approached zero (i.e. two “null phase positions”); this was true, even for the most direction selective cells. However, the measured responses were consistent with the hypothesis that direction selectivity is a consequence of the linear spatiotemporal receptive-field structure, coupled with the nonlinearities revealed by the contrast-response function: contrast gain control, halfwave rectification, and expansive exponent. When arranged in a particular sequence, each of these linear and nonlinear mechanisms performs a useful function in a general model of simple cells. The linear spatiotemporal receptive field initiates stimulus selectivity (for direction, orientation, spatial frequency, etc.). The expansive response exponent enhances selectivity. The contrast-set gain control maintains selectivity (over a wide range of contrasts, in spite of the limited dynamic response range and steep slope of the contrast-response function). Rectification conserves metabolic energy.

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Contrast gain control in the kitten's visual system

Journal of Neurophysiology ◽

10.1152/jn.1985.54.3.668 ◽

1985 ◽

Vol 54 (3) ◽

pp. 668-675 ◽

Cited By ~ 26

Author(s):

G. Sclar ◽

I. Ohzawa ◽

R. D. Freeman

Keyword(s):

Gain Control ◽

Sine Wave ◽

Response Functions ◽

Cortical Cells ◽

Contrast Gain ◽

Contrast Gain Control ◽

Response Range ◽

Adult Cats ◽

Contrast Response ◽

Different Levels

We have studied the effects of contrast adaptation on cortical cells from 4- and 6-wk-old kittens (49 and 47 cells, respectively) using sine-wave grating stimuli. We wished to know if the effects of adaptation to different contrast levels are more extensive than those in adult animals. Our experiments involved adapting cells to different contrasts (3.1, 12.5, and 50%) while concurrently measuring their contrast-response functions at each of these different levels. We found qualitatively that the effects of adaptation in the kitten are similar to those we have previously documented in adult animals (19). Contrast-response functions are laterally shifted along the log-contrast axis, effectively matching the response range of the cells to prevailing contrast levels. The degree to which this occurred varied from cell to cell. The average degree to which cells showed these effects, as assessed both qualitatively and quantitatively, was greater for kittens than for adult cats, and greater for 4-wk-old kittens than for those aged 6 wk. This suggests that susceptibility to adaptation varies as a function of age. Additional studies were undertaken with the intent of localizing these adaptive effects. First, lateral geniculate cells and fibers (n = 23) were studied with our standard protocol, and second, we investigated the degree to which the effects of adaptation of cortical cells transferred interocularly.(ABSTRACT TRUNCATED AT 250 WORDS)

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A Simple Coding Procedure Enhances a Neuron's Information Capacity

Zeitschrift für Naturforschung C ◽

10.1515/znc-1981-9-1040 ◽

1981 ◽

Vol 36 (9-10) ◽

pp. 910-912 ◽

Cited By ~ 511

Author(s):

Simon Laughlin

Keyword(s):

Information Theory ◽

Probability Distribution ◽

Response Function ◽

Compound Eye ◽

Information Capacity ◽

Cumulative Probability ◽

Natural Scenes ◽

First Order ◽

Contrast Response Function ◽

Contrast Response

Abstract The contrast-response function of a class of first order intemeurons in the fly's compound eye approximates to the cumulative probability distribution of contrast levels in natural scenes. Elementary information theory shows that this matching enables the neurons to encode contrast fluctuations most efficiently.

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