scholarly journals Learning and attention increase visual response selectivity through distinct mechanisms

Neuron ◽  
2021 ◽  
Author(s):  
Jasper Poort ◽  
Katharina A. Wilmes ◽  
Antonin Blot ◽  
Angus Chadwick ◽  
Maneesh Sahani ◽  
...  
Keyword(s):  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Stefano Rozzi ◽  
Marco Bimbi ◽  
Alfonso Gravante ◽  
Luciano Simone ◽  
Leonardo Fogassi

AbstractThe ventral part of lateral prefrontal cortex (VLPF) of the monkey receives strong visual input, mainly from inferotemporal cortex. It has been shown that VLPF neurons can show visual responses during paradigms requiring to associate arbitrary visual cues to behavioral reactions. Further studies showed that there are also VLPF neurons responding to the presentation of specific visual stimuli, such as objects and faces. However, it is largely unknown whether VLPF neurons respond and differentiate between stimuli belonging to different categories, also in absence of a specific requirement to actively categorize or to exploit these stimuli for choosing a given behavior. The first aim of the present study is to evaluate and map the responses of neurons of a large sector of VLPF to a wide set of visual stimuli when monkeys simply observe them. Recent studies showed that visual responses to objects are also present in VLPF neurons coding action execution, when they are the target of the action. Thus, the second aim of the present study is to compare the visual responses of VLPF neurons when the same objects are simply observed or when they become the target of a grasping action. Our results indicate that: (1) part of VLPF visually responsive neurons respond specifically to one stimulus or to a small set of stimuli, but there is no indication of a “passive” categorical coding; (2) VLPF neuronal visual responses to objects are often modulated by the task conditions in which the object is observed, with the strongest response when the object is target of an action. These data indicate that VLPF performs an early passive description of several types of visual stimuli, that can then be used for organizing and planning behavior. This could explain the modulation of visual response both in associative learning and in natural behavior.


2014 ◽  
Vol 111 (12) ◽  
pp. 2589-2602 ◽  
Author(s):  
Hiroshi Tamura ◽  
Yoshiya Mori ◽  
Hidekazu Kaneko

Detailed knowledge of neuronal circuitry is necessary for understanding the mechanisms underlying information processing in the brain. We investigated the organization of horizontal functional interactions in the inferior temporal cortex of macaque monkeys, which plays important roles in visual object recognition. Neuronal activity was recorded from the inferior temporal cortex using an array of eight tetrodes, with spatial separation between paired neurons up to 1.4 mm. We evaluated functional interactions on a time scale of milliseconds using cross-correlation analysis of neuronal activity of the paired neurons. Visual response properties of neurons were evaluated using responses to a set of 100 visual stimuli. Adjacent neuron pairs tended to show strong functional interactions compared with more distant neuron pairs, and neurons with similar stimulus preferences tended to show stronger functional interactions than neurons with different stimulus preferences. Thus horizontal functional interactions in the inferior temporal cortex appear to be organized according to both cortical distances and similarity in stimulus preference between neurons. Furthermore, the relationship between strength of functional interactions and similarity in stimulus preference observed in distant neuron pairs was more prominent than in adjacent pairs. The results suggest that functional circuitry is specifically organized, depending on the horizontal distances between neurons. Such specificity endows each circuit with unique functions.


1938 ◽  
Vol 24 (3) ◽  
pp. 125-130 ◽  
Author(s):  
W. J. Crozier ◽  
E. Wolf ◽  
G. Zerrahn-Wolf
Keyword(s):  

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Mulugeta Semework ◽  
Sara C Steenrod ◽  
Michael E Goldberg

Humans effortlessly establish a gist-like memory of their environment whenever they enter a new place, a memory that can guide action even in the absence of vision. Neurons in the lateral intraparietal area (LIP) of the monkey exhibit a form of this environmental memory. These neurons respond when a monkey makes a saccade that brings the spatial location of a stimulus that appeared on a number of prior trials, but not on the present trial, into their receptive fields (RFs). The stimulus need never have appeared in the neuron’s RF. This memory response is usually weaker, with a longer latency than the neuron’s visual response. We suggest that these results demonstrate that LIP has access to a supraretinal memory of space, which is activated when the spatial location of the vanished stimulus can be described by a retinotopic vector from the center of gaze to the remembered spatial location.


2013 ◽  
Vol 56 (4) ◽  
pp. 1075-1084 ◽  
Author(s):  
Carina Pals ◽  
Anastasios Sarampalis ◽  
Deniz Başkent

Purpose Fitting a cochlear implant (CI) for optimal speech perception does not necessarily optimize listening effort. This study aimed to show that listening effort may change between CI processing conditions for which speech intelligibility remains constant. Method Nineteen normal-hearing participants listened to CI simulations with varying numbers of spectral channels. A dual-task paradigm combining an intelligibility task with either a linguistic or nonlinguistic visual response-time (RT) task measured intelligibility and listening effort. The simultaneously performed tasks compete for limited cognitive resources; changes in effort associated with the intelligibility task are reflected in changes in RT on the visual task. A separate self-report scale provided a subjective measure of listening effort. Results All measures showed significant improvements with increasing spectral resolution up to 6 channels. However, only the RT measure of listening effort continued improving up to 8 channels. The effects were stronger for RTs recorded during listening than for RTs recorded between listening. Conclusion The results suggest that listening effort decreases with increased spectral resolution. Moreover, these improvements are best reflected in objective measures of listening effort, such as RTs on a secondary task, rather than intelligibility scores or subjective effort measures.


2021 ◽  
Vol 15 (4) ◽  
pp. 497-503
Author(s):  
Qihang Liu ◽  
Yueli Jiang ◽  
Mingqian Zhao ◽  
Jin Miao ◽  
Zhongjun Gong ◽  
...  

To understand the visual sensitivity of western flower thrips to 350–450 nm light, we examined thrips selective response effect and the effect of white light on thrips visual response effect. The results showed that the visual selection response to Ultra Violet (UV) light at 360–365 nm, the approach sensitivity to 380–385 nm light with 6000 lx was respectively the best (15.59, 7.26%), while under light energy, both of them to 360–365 nm light with 60 mW/cm2 were the best (20.04, 11.13%). Under contrast white light, the most sensitive UV spectra of thrips respectively caused by illumination, light energy was 380–385, 360–365 nm, and white light enhanced thrips visual response effect to UV light, which further increased by the increasing intensity, showing that under illumination, the visual response effect to 380–385 nm light with 6000 lx was the best (51.21,69.78%), while that to 360–365 nm light with 60 mW/cm2 were the best (43.98, 65.68%), originated from the different intensity spread by light energy and illumination. These results indicate that the change of photo-stimulus intensity property can regulated thrips visual sensitivity to enhance the phototactic effect.


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