scholarly journals Properties of predictive gain modulation in a dragonfly visual neuron

2019 ◽  
Vol 222 (17) ◽  
pp. jeb207316 ◽  
Author(s):  
Joseph M. Fabian ◽  
James R. Dunbier ◽  
David C. O'Carroll ◽  
Steven D. Wiederman
Keyword(s):  
Gain Modulation ◽  
Visual Neuron

scholarly journals Properties of Predictive Gain Modulation in a Dragonfly Visual Neuron

2018 ◽  
Author(s):  
Joseph M Fabian ◽  
James R Dunbier ◽  
David C O'Carroll ◽  
Steven D Wiederman
Keyword(s):  
Receptive Field ◽  
Visual Signal ◽  
Gain Modulation ◽  
Success Rates ◽  
Gain Enhancement ◽  
Input Signals ◽  
Target Detecting ◽  
Motion Detectors ◽  
Visual Neuron ◽  
Over Time

Dragonflies pursue and capture tiny prey and conspecifics with extremely high success rates. These moving targets represent a small visual signal on the retina and successful chases require accurate detection and amplification by downstream neuronal circuits. This amplification has been observed in a population of neurons called Small Target Motion Detectors (STMDs), through a mechanism we termed predictive gain modulation. As targets drift through the receptive field responses build slowly over time. This gain is modulated across the receptive field, enhancing sensitivity just ahead of the targets path, with suppression of activity elsewhere in the surround. Whilst some properties of this mechanism have been described, it is not yet known which stimulus parameters are required to generate this gain modulation. Previous work suggested that the strength of gain enhancement was predominantly determined by the duration of the targets prior path. Here we show that the predictive gain modulation is more than a sluggish build-up of gain over time. Rather, gain is dependent on both past and present parameters of the stimulus. We also describe response variability as a major challenge of target detecting neurons and propose that the predictive gain modulations role is to drive neurons into response saturation, thus minimising neuronal variability despite noisy visual input signals.

Auditory Cortex Attentional Gain Modulation is Impaired in First-Episode Psychosis

2021 ◽  
Vol 89 (9) ◽  
pp. S347
Author(s):  
Mark T. Curtis ◽  
Xi Ren ◽  
Vanessa Fishel ◽  
Natasha Torrence ◽  
Yiming Wang ◽  
...  
Keyword(s):  
Auditory Cortex ◽  
First Episode Psychosis ◽  
First Episode ◽  
Gain Modulation ◽  
Episode Psychosis

EXPRESS: How the size of exogenous attentional cues alters visual performance: from response gain to contrast gain

2021 ◽  
pp. 174702182110248
Author(s):  
Xiaogang Wu ◽  
Aijun Wang ◽  
Ming Zhang
Keyword(s):  
Visual Selective Attention ◽  
Visual Performance ◽  
Target Size ◽  
Field Size ◽  
Gain Modulation ◽  
Absolute Size ◽  
Contrast Gain ◽  
Exogenous Cues ◽  
Exogenous Cue ◽  
Attentional Cues

The normalization model of attention (NMoA) predicts that the attention gain pattern is mediated by changes in the size of the attentional field and stimuli. However, existing studies have not measured gain patterns when the relative sizes of stimuli are changed. To investigate the NMoA, the present study manipulated the attentional field size, namely, the exogenous cue size. Moreover, we assessed whether the relative rather than the absolute size of the attentional field matters, either by holding the target size constant and changing the cue size (experiments 1-3) or by holding the cue size constant and changing the target size (experiment 4), in a spatial cueing paradigm of psychophysical procedures. The results show that the gain modulations changed from response gain to contrast gain when the precue size changed from small to large relative to the target size (experiments 1-3). Moreover, when the target size was once again made larger than the precue size, there was still a change in response gain (experiment 4). These results suggest that the size of exogenous cues plays an important role in adjusting the attentional field and that relative changes rather than absolute changes to exogenous cue size determine gain modulation. These results are consistent with the prediction of the NMoA and provide novel insights into gain modulations of visual selective attention.

All-optical differentiator based on cross-gain modulation in semiconductor optical amplifier

2007 ◽  
Vol 32 (20) ◽  
pp. 3029 ◽  
Author(s):  
Jing Xu ◽  
Xinliang Zhang ◽  
Jianji Dong ◽  
Deming Liu ◽  
Dexiu Huang
Keyword(s):  
Semiconductor Optical Amplifier ◽  
Optical Amplifier ◽  
Gain Modulation ◽  
Cross Gain Modulation ◽  
All Optical ◽  
Optical Differentiator

Gain modulation of recurrent networks

2000 ◽  
Vol 32-33 ◽  
pp. 623-628 ◽  
Author(s):  
Jian Zhang ◽  
L.F. Abbott
Keyword(s):  
Recurrent Networks ◽  
Gain Modulation

Analytic model for gain modulation in EDFAs

2002 ◽  
Vol 20 (6) ◽  
pp. 975-985 ◽  
Author(s):  
S. Novak ◽  
A. Moesle
Keyword(s):  
Analytic Model ◽  
Gain Modulation

Time Course of Cross-Orientation Suppression in the Early Visual Cortex

2009 ◽  
Vol 101 (3) ◽  
pp. 1463-1479 ◽  
Author(s):  
Rui Kimura ◽  
Izumi Ohzawa
Keyword(s):  
Visual Cortex ◽  
Time Course ◽  
Individual Component ◽  
Correlation Method ◽  
Suppressive Effect ◽  
Negative Response ◽  
Reverse Correlation ◽  
Response Onset ◽  
Early Visual Cortex ◽  
Visual Neuron

Responses of a visual neuron to optimally oriented stimuli can be suppressed by a superposition of another grating with a different orientation. This effect is known as cross-orientation suppression. However, it is still not clear whether the effect is intracortical in origin or a reflection of subcortical processes. To address this issue, we measured spatiotemporal responses to a plaid pattern, a superposition of two gratings, as well as to individual component gratings (optimal and mask) using a subspace reverse-correlation method. Suppression for the plaid was evaluated by comparing the response to that for the optimal grating. For component stimuli, excitatory and negative responses were defined as responses more positive and negative, respectively, than that to a blank stimulus. The suppressive effect for plaids was observed in the vast majority of neurons. However, only ∼30% of neurons showed the negative response to mask-only gratings. The magnitudes of negative responses to mask-only stimuli were correlated with the degree of suppression for plaid stimuli. Comparing the latencies, we found that the suppression for the plaids starts at about the same time or slightly later than the response onset for the optimal grating and reaches its maximum at about the same time as the peak latency for the mask-only grating. Based on these results, we propose that in addition to the suppressive effect originating at the subcortical stage, delayed suppressive signals derived from the intracortical networks act on the neuron to generate cross-orientation suppression.

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