A Neural Model for Attentional Modulation of Lateral Interactions in the Visual Cortex

2007 ◽  
pp. 42-51 ◽  
Author(s):  
Mia Šetić ◽  
Dražen Domijan
Keyword(s):  
Visual Cortex ◽  
Neural Model ◽  
Lateral Interactions ◽  
Attentional Modulation

scholarly journals The Effect of Attention on Neuronal Responses to High and Low Contrast Stimuli

2010 ◽  
Vol 104 (2) ◽  
pp. 960-971 ◽  
Author(s):  
Joonyeol Lee ◽  
John H. R. Maunsell
Keyword(s):  
Cerebral Cortex ◽  
Visual Cortex ◽  
Rhesus Monkeys ◽  
Receptive Fields ◽  
Visual Area ◽  
Neuronal Responses ◽  
Attentional Modulation ◽  
Low Contrast ◽  
Middle Temporal ◽  
Visual Area Mt

It remains unclear how attention affects the tuning of individual neurons in visual cerebral cortex. Some observations suggest that attention preferentially enhances responses to low contrast stimuli, whereas others suggest that attention proportionally affects responses to all stimuli. Resolving how attention affects responses to different stimuli is essential for understanding the mechanism by which it acts. To explore the effects of attention on stimuli of different contrasts, we recorded from individual neurons in the middle temporal visual area (MT) of rhesus monkeys while shifting their attention between preferred and nonpreferred stimuli within their receptive fields. This configuration results in robust attentional modulation that makes it possible to readily distinguish whether attention acts preferentially on low contrast stimuli. We found no evidence for greater enhancement of low contrast stimuli. Instead, the strong attentional modulations were well explained by a model in which attention proportionally enhances responses to stimuli of all contrasts. These data, together with observations on the effects of attention on responses to other stimulus dimensions, suggest that the primary effect of attention in visual cortex may be to simply increase the strength of responses to all stimuli by the same proportion.

Lateral Interactions in Visual Cortex

1990 ◽  
Vol 55 (0) ◽  
pp. 663-677 ◽  
Author(s):  
C.D. Gilbert ◽  
J.A. Hirsch ◽  
T.N. Wiesel
Keyword(s):  
Visual Cortex ◽  
Lateral Interactions

scholarly journals A Neural Model of Figure–Ground Organization

2007 ◽  
Vol 97 (6) ◽  
pp. 4310-4326 ◽  
Author(s):  
Edward Craft ◽  
Hartmut Schütze ◽  
Ernst Niebur ◽  
Rüdiger von der Heydt
Keyword(s):  
Neural Circuits ◽  
Neural Model ◽  
Self Organization ◽  
Lateral Interactions ◽  
Early Visual Cortex ◽  
Experimental Findings ◽  
Psychophysical Studies ◽  
Contour Grouping ◽  
Ground Organization

Psychophysical studies suggest that figure–ground organization is a largely autonomous process that guides—and thus precedes—allocation of attention and object recognition. The discovery of border-ownership representation in single neurons of early visual cortex has confirmed this view. Recent theoretical studies have demonstrated that border-ownership assignment can be modeled as a process of self-organization by lateral interactions within V2 cortex. However, the mechanism proposed relies on propagation of signals through horizontal fibers, which would result in increasing delays of the border-ownership signal with increasing size of the visual stimulus, in contradiction with experimental findings. It also remains unclear how the resulting border-ownership representation would interact with attention mechanisms to guide further processing. Here we present a model of border-ownership coding based on dedicated neural circuits for contour grouping that produce border-ownership assignment and also provide handles for mechanisms of selective attention. The results are consistent with neurophysiological and psychophysical findings. The model makes predictions about the hypothetical grouping circuits and the role of feedback between cortical areas.

scholarly journals Dynamic causal modelling of lateral interactions in the visual cortex

NeuroImage ◽  
2013 ◽  
Vol 66 ◽  
pp. 563-576 ◽  
Author(s):  
D.A. Pinotsis ◽  
D.S. Schwarzkopf ◽  
V. Litvak ◽  
G. Rees ◽  
G. Barnes ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Lateral Interactions ◽  
Causal Modelling ◽  
Dynamic Causal Modelling

scholarly journals Attentional modulation of oscillatory activity in human visual cortex

NeuroImage ◽  
2003 ◽  
Vol 20 (1) ◽  
pp. 98-113 ◽  
Author(s):  
Noriko Yamagishi ◽  
Daniel E Callan ◽  
Naokazu Goda ◽  
Stephen J Anderson ◽  
Yoshikazu Yoshida ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Oscillatory Activity ◽  
Attentional Modulation ◽  
Human Visual Cortex

100 Years of Benham's Top in Colour Science

Perception ◽  
1995 ◽  
Vol 24 (6) ◽  
pp. 695-717 ◽  
Author(s):  
Christoph von Campenhausen ◽  
Jürgen Schramme
Keyword(s):  
Visual Cortex ◽  
Neural Activity ◽  
Medical Diagnosis ◽  
Side Effect ◽  
Neural Mechanism ◽  
Lateral Interactions ◽  
Colour Constancy ◽  
Binocular Fusion ◽  
Normal Colour ◽  
Phase Sensitive

For 100 years Benham's top has been a popular device demonstrating pattern-induced flicker colours (PIFCs). Results of early and recent investigations on PIFCs are reported and show that the phenomenon originates in phase-sensitive lateral interactions of modulated neural activity in the retina followed by additional spatial interactions in the visual cortex behind the locus of binocular fusion. Colour matches with normal colour stimuli indicate that S/(M + L) opponent neurons are involved. Dichromats do not find matching stimuli for all PIFCs. PIFCs may become useful in medical diagnosis. The phenomenon is interpreted as a side effect of a neural mechanism providing colour constancy under normal stimulus conditions.

scholarly journals Attention hinges on tuned normalization strength within human visual cortex

2019 ◽  
Author(s):  
Ilona M. Bloem ◽  
Sam Ling
Keyword(s):  
Visual Cortex ◽  
Attentional Modulation ◽  
Human Visual Cortex ◽  
Divisive Normalization ◽  
Neural Computations ◽  
Do So

AbstractAlthough attention is known to increase the gain of visuocortical responses, its underlying neural computations remain unclear. Here, we used fMRI to test the hypothesis that a neural population’s ability to be modulated by attention is dependent on divisive normalization. To do so, we leveraged the feature-tuned properties of normalization and found that visuocortical responses to stimuli sharing features normalized each other more strongly. Comparing these normalization measures to measures of attentional modulation, we discovered that subpopulations that exhibited stronger normalization also exhibited larger attentional benefits. In a converging experiment, we demonstrated that attentional benefits were greatest when a subpopulation was forced into a state of stronger normalization. We propose a tuned normalization model of attention that parsimoniously accounts for many properties of our results, suggesting that the degree to which a subpopulation exhibits normalization plays a role in dictating its potential for attentional benefits.

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