Crossmodal attention alters auditory contrast sensitivity

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.

scholarly journals Electrophysiological measures of visual suppression

2021 ◽  
Author(s):  
Daniel H Baker ◽  
Greta Vilidaite ◽  
Alex R Wade
Keyword(s):  
Response Function ◽  
Second Harmonic ◽  
Meta Analysis ◽  
Gain Control ◽  
Spatial Location ◽  
Sine Wave ◽  
Harmonic Frequency ◽  
Contrast Gain ◽  
Contrast Response Function ◽  
Contrast Response

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.

Derivation of the Visual Contrast Response Function by Maximizing Information Rate

2002 ◽  
Vol 14 (3) ◽  
pp. 527-542 ◽  
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.

AB052. A standardized quantification of the visual contrast response function

2018 ◽  
Vol 3 ◽  
pp. AB052-AB052
Author(s):  
Marc Demers ◽  
Nelson Cortes ◽  
Visou Andy ◽  
Bruno Oliveira ◽  
Alexie Byrns ◽  
...  
Keyword(s):  
Response Function ◽  
Visual Contrast ◽  
Contrast Response Function ◽  
Contrast Response

scholarly journals Steady-state measures of visual suppression

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

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.

Dynamic shifts of the contrast-response function

1997 ◽  
Vol 14 (3) ◽  
pp. 577-587 ◽  
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.

A Simple Coding Procedure Enhances a Neuron's Information Capacity

1981 ◽  
Vol 36 (9-10) ◽  
pp. 910-912 ◽  
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.

scholarly journals Porcine global flash multifocal electroretinogram: Possible mechanisms for the glaucomatous changes in contrast response function

2008 ◽  
Vol 48 (16) ◽  
pp. 1726-1734 ◽  
Author(s):  
Patrick H.W. Chu ◽  
Henry H.L. Chan ◽  
Yiu-fai Ng ◽  
Brian Brown ◽  
Andrew W. Siu ◽  
...  
Keyword(s):  
Response Function ◽  
Multifocal Electroretinogram ◽  
Global Flash ◽  
Contrast Response Function ◽  
Contrast Response

scholarly journals The motion after-effect: local and global contributions to contrast sensitivity

2009 ◽  
Vol 276 (1662) ◽  
pp. 1545-1554 ◽  
Author(s):  
Karin Nordström ◽  
David C O'Carroll
Keyword(s):  
Noise Analysis ◽  
Motion Adaptation ◽  
Contrast Gain ◽  
Contrast Response Function ◽  
After Effect ◽  
Widespread Phenomenon ◽  
Motion Coding ◽  
Processing Techniques ◽  
Contrast Response ◽  
Peripheral Sensory

Motion adaptation is a widespread phenomenon analogous to peripheral sensory adaptation, presumed to play a role in matching responses to prevailing current stimulus parameters and thus to maximize efficiency of motion coding. While several components of motion adaptation (contrast gain reduction, output range reduction and motion after-effect) have been described, previous work is inconclusive as to whether these are separable phenomena and whether they are locally generated. We used intracellular recordings from single horizontal system neurons in the fly to test the effect of local adaptation on the full contrast-response function for stimuli at an unadapted location. We show that contrast gain and output range reductions are primarily local phenomena and are probably associated with spatially distinct synaptic changes, while the antagonistic after-potential operates globally by transferring to previously unadapted locations. Using noise analysis and signal processing techniques to remove ‘spikelets’, we also characterize a previously undescribed alternating current component of adaptation that can explain several phenomena observed in earlier studies.

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