Focused Attention Modulates Visual Responses in the Primate Prefrontal Cortex

2004 ◽  
Vol 91 (2) ◽  
pp. 855-862 ◽  
Author(s):  
Joseph F.X. DeSouza ◽  
Stefan Everling
Keyword(s):  
Prefrontal Cortex ◽  
Visual Stimuli ◽  
Initial Response ◽  
Single Stimulus ◽  
Focused Attention ◽  
Visual Responses ◽  
Enhanced Activity

Several current models propose an important role of the prefrontal cortex (PFC) in attention. To test the effects of attention in PFC, we recorded from PFC neurons in monkeys performing a task in which they had to attend to one hemifield and wait for a single stimulus that matched a previously presented cue. Neurons exhibited a slight decrease in their initial response and an enhanced activity late in the response to a stimulus at the cued location. The data demonstrate attentional effects on the activity of PFC neurons but they also show that single visual stimuli are initially represented in the activity of PFC neurons even when they are behaviorally irrelevant.

scholarly journals Involuntary orienting and conflict resolution during auditory attention: The role of ventral and dorsal streams

2020 ◽  
Author(s):  
Hannah J Stewart ◽  
Dawei Shen ◽  
Nasim Sham ◽  
Claude Alain
Keyword(s):  
Prefrontal Cortex ◽  
Conflict Resolution ◽  
Response Times ◽  
Brain Activity ◽  
Superior Temporal Gyrus ◽  
Spatial Location ◽  
Irrelevant Feature ◽  
Enhanced Activity ◽  
Task Irrelevant

AbstractSelective attention to sound object features such as pitch and location is associated with enhanced brain activity in ventral and dorsal streams, respectively. We examined the role of these pathways in involuntary orienting and conflict resolution using functional magnetic resonance imaging (fMRI). Participants were presented with two tones that may share, or not, the same non-spatial (frequency) or spatial (location) auditory features. In separate blocks of trials, participants were asked to attend to sound frequency or sound location and ignore the change in the task-irrelevant feature. In both attend-frequency and attend-location tasks, response times were slower when the task-irrelevant feature changed than when it stayed the same (involuntary orienting). This behavioural cost coincided with enhanced activity in the prefrontal cortex and superior temporal gyrus (STG). Conflict resolution was examined by comparing situations where the change in stimulus features was congruent (both features changed) and incongruent (only one feature changed). Participants were slower and less accurate for incongruent than congruent sound features. This congruency effect was associated with enhanced activity in the prefrontal cortex, and was greater in the right STG and medial frontal cortex during the attend-location than during the attend-frequency task. Together, these findings do not support a strict division of ‘labour’ into ventral and dorsal streams, but rather suggest interactions between these pathways in situations involving changes in task-irrelevant sound feature and conflict resolution. These findings also validate the Test of Attention in Listening task by revealing distinct neural correlates for involuntary orienting and conflict resolution.

scholarly journals The role of dorsolateral and ventromedial prefrontal cortex in the processing of emotional dimensions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vahid Nejati ◽  
Reyhaneh Majdi ◽  
Mohammad Ali Salehinejad ◽  
Michael A. Nitsche
Keyword(s):  
Prefrontal Cortex ◽  
Emotional Processing ◽  
Dorsolateral Prefrontal Cortex ◽  
Visual Stimuli ◽  
Ventromedial Prefrontal Cortex ◽  
Three Dimensions ◽  
Anodal Tdcs ◽  
Stimulation Condition ◽  
Dorsolateral Prefrontal

AbstractThe ventromedial and dorsolateral prefrontal cortex are two major prefrontal regions that usually interact in serving different cognitive functions. On the other hand, these regions are also involved in cognitive processing of emotions but their contribution to emotional processing is not well-studied. In the present study, we investigated the role of these regions in three dimensions (valence, arousal and dominance) of emotional processing of stimuli via ratings of visual stimuli performed by the study participants on these dimensions. Twenty- two healthy adult participants (mean age 25.21 ± 3.84 years) were recruited and received anodal and sham transcranial direct current stimulation (tDCS) (1.5 mA, 15 min) over the dorsolateral prefrontal cortex (dlPFC) and and ventromedial prefrontal cortex (vmPFC) in three separate sessions with an at least 72-h interval. During stimulation, participants underwent an emotional task in each stimulation condition. The task included 100 visual stimuli and participants were asked to rate them with respect to valence, arousal, and dominance. Results show a significant effect of stimulation condition on different aspects of emotional processing. Specifically, anodal tDCS over the dlPFC significantly reduced valence attribution for positive pictures. In contrast, anodal tDCS over the vmPFC significantly reduced arousal ratings. Dominance ratings were not affected by the intervention. Our results suggest that the dlPFC is involved in control and regulation of valence of emotional experiences, while the vmPFC might be involved in the extinction of arousal caused by emotional stimuli. Our findings implicate dimension-specific processing of emotions by different prefrontal areas which has implications for disorders characterized by emotional disturbances such as anxiety or mood disorders.

Alcohol Dependence Conceptualized as a Stress Disorder

2019 ◽  
pp. 198-220
Author(s):  
Leandro F. Vendruscolo ◽  
George F. Koob
Keyword(s):  
Prefrontal Cortex ◽  
Alcohol Use ◽  
Alcohol Dependence ◽  
Glucocorticoid Receptors ◽  
Critical Role ◽  
Emotional States ◽  
Brain Circuits ◽  
Negative Emotional State ◽  
Alcohol Alcohol

Alcohol use disorder is a chronically relapsing disorder that involves (1) compulsivity to seek and take alcohol, (2) difficulty in limiting alcohol intake, and (3) emergence of a negative emotional state (e.g., dysphoria, anxiety, irritability) in the absence of alcohol. Alcohol addiction encompasses a three-stage cycle that becomes more intense as alcohol use progresses: binge/intoxication, withdrawal/negative affect, and preoccupation/anticipation. These stages engage neuroadaptations in brain circuits that involve the basal ganglia (reward hypofunction), extended amygdala (stress sensitization), and prefrontal cortex (executive function disorder). This chapter discusses key neuroadaptations in the hypothalamic and extrahypothalamic stress systems and the critical role of glucocorticoid receptors. These neuroadaptations contribute to negative emotional states that powerfully drive compulsive alcohol drinking and seeking. These changes in association with a disruption of prefrontal cortex function that lead to cognitive deficits and poor decision making contribute to the chronic relapsing nature of alcohol dependence.

scholarly journals Visual response of ventrolateral prefrontal neurons and their behavior-related modulation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Stefano Rozzi ◽  
Marco Bimbi ◽  
Alfonso Gravante ◽  
Luciano Simone ◽  
Leonardo Fogassi
Keyword(s):  
Visual Cues ◽  
Visual Stimuli ◽  
Visual Response ◽  
Visual Responses ◽  
Action Execution ◽  
Natural Behavior ◽  
Large Sector ◽  
Small Set ◽  
Early Passive ◽  
Task Conditions

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.

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