scholarly journals Different contribution of the monkey prefrontal and premotor dorsal cortex in decision-making supported by inferential reasoning

2021 ◽  
Author(s):  
Surabhi Ramawat ◽  
Valentina Mione ◽  
Fabio Di Bello ◽  
Giampiero Bardella ◽  
Aldo Genovesio ◽  
...  
Keyword(s):  
Neuronal Activity ◽  
Target Item ◽  
Neural Encoding ◽  
Dorsal Cortex ◽  
Brain Areas ◽  
Proper Action ◽  
Item Position ◽  
Opposite Position ◽  
Dorsolateral Prefrontal ◽  
Rank Difference

Several studies reported similar neural modulations between brain areas of the frontal cortex, such as the dorsolateral prefrontal (DLPFC) and the premotor dorsal (PMd) cortex, in tasks requiring encoding of the abstract rules for selecting the proper action. Here, we compared the DLPFC and PMd neuronal activity of monkeys trained in choosing the highest ranking image of pair (target item), selected from an arbitrarily rank-ordered set (A>B>C>D>E>F) in the context of a transitive inference task. Once acquired by trial-and-error, the ordinal relationship between pairs of adjacent images (i.e. A>B; B>C; C>D; D>E; E>F), monkeys were tested in inferring the ordinal relation between items of the list not paired during learning. During inferential decisions, we observed that the choice accuracy increased and the reaction time decreased as the rank difference between the compared items enhanced. This result is in line with the hypothesis that after learning, the monkeys built an abstract mental representation of the ranked items, where rank comparisons correspond to the item position comparison on this representation. In both brain areas, we observed higher neuronal activity when the target item appeared in a specific location on the screen, with respect to the opposite position and that this difference was particularly enhanced at lower degrees of difficulty. By comparing the time evolution of the activity of the two areas, we revealed that the neural encoding of target item spatial position occurred earlier in DLPFC than in PMd, while in PMd the spatial encoding duration was longer.

scholarly journals Prefrontal and Parietal Attractor Networks Mediate Working Memory Judgments

2020 ◽  
Author(s):  
Sihai Li ◽  
Christos Constantinidis ◽  
Xue-Lian Qi
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Critical Role ◽  
Memory Task ◽  
Delayed Response ◽  
Persistent Activity ◽  
Neural Basis ◽  
Brain Areas ◽  
Dorsolateral Prefrontal

ABSTRACTThe dorsolateral prefrontal cortex plays a critical role in spatial working memory and its activity predicts behavioral responses in delayed response tasks. Here we addressed whether this predictive ability extends to categorical judgments based on information retained in working memory, and is present in other brain areas. We trained monkeys in a novel, Match-Stay, Nonmatch-Go task, which required them to observe two stimuli presented in sequence with an intervening delay period between them. If the two stimuli were different, the monkeys had to saccade to the location of the second stimulus; if they were the same, they held fixation. Neurophysiological recordings were performed in areas 8a and 46 of the dlPFC and 7a and lateral intraparietal cortex (LIP) of the PPC. We hypothesized that random drifts causing the peak activity of the network to move away from the first stimulus location and towards the location of the second stimulus would result in categorical errors. Indeed, for both areas, when the first stimulus appeared in a neuron’s preferred location, the neuron showed significantly higher firing rates in correct than in error trials. When the first stimulus appeared at a nonpreferred location and the second stimulus at a preferred, activity in error trials was higher than in correct. The results indicate that the activity of both dlPFC and PPC neurons is predictive of categorical judgments of information maintained in working memory, and the magnitude of neuronal firing rate deviations is revealing of the contents of working memory as it determines performance.SIGNIFICANCE STATEMENTThe neural basis of working memory and the areas mediating this function is a topic of controversy. Persistent activity in the prefrontal cortex has traditionally been thought to be the neural correlate of working memory, however recent studies have proposed alternative mechanisms and brain areas. Here we show that persistent activity in both the dorsolateral prefrontal cortex and posterior parietal cortex predicts behavior in a working memory task that requires a categorical judgement. Our results offer support to the idea that a network of neurons in both areas act as an attractor network that maintains information in working memory, which informs behavior.

scholarly journals Linking neural activity to complex decisions

2013 ◽  
Vol 30 (5-6) ◽  
pp. 331-342 ◽  
Author(s):  
BENJAMIN HAYDEN ◽  
TATIANA PASTERNAK
Keyword(s):  
Decision Making ◽  
Neuronal Activity ◽  
Neural Activity ◽  
Psychological Processes ◽  
Direct Link ◽  
Brain Areas ◽  
Seminal Work ◽  
Choice Processes ◽  
Neuronal Mechanisms ◽  
Complex Forms

AbstractIn the 1990s, seminal work from Newsome and colleagues made it possible to study the neuronal mechanisms of simple perceptual decisions. The key strength of this work was the clear and direct link between neuronal activity and choice processes. Since then, a great deal of research has extended these initial discoveries to more complex forms of decision making, with the goal of bringing the same strength of linkage between neural and psychological processes. Here, we discuss the progress of two such research programs, namely our own, that are aimed at understanding memory-guided decisions and reward-guided decisions. These problems differ in the relevant brain areas, in the progress that has been achieved, and in the extent of broader understanding achieved so far. However, they are unified by the use of theoretical insights about how to link neuronal activity to decisions.

scholarly journals Trans-Synaptic Spread of Amyloid-βin Alzheimer’s Disease: Paths toβ-Amyloidosis

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Annabella Pignataro ◽  
Silvia Middei
Keyword(s):  
Neuronal Activity ◽  
Amyloid Plaques ◽  
Brain Regions ◽  
Amyloid Peptide ◽  
Synaptic Connections ◽  
Brain Areas ◽  
Close Link ◽  
Gradual Accumulation ◽  
Cortical Regions ◽  
Activity Dependent

Neuronal activity has a strong causal role in the production and release of the neurotoxicβ-amyloid peptide (Aβ). Because of this close link, gradual accumulation of Aβinto amyloid plaques has been reported in brain areas with intense neuronal activity, including cortical regions that display elevated activation at resting state. However, the link between Aβand activity is not always linear and recent studies report exceptions to the view of “more activity, more plaques.” Here, we review the literature about the activity-dependent production of Aβin both human cases and AD models and focus on the evidences that brain regions with elevated convergence of synaptic connections (herein referred to as brain nodes) are particularly vulnerable to Aβaccumulation. Next, we will examine data supporting the hypothesis that, since Aβis released from synaptic terminals,β-amyloidosis can spread in AD brain by advancing through synaptically connected regions, which makes brain nodes vulnerable to Aβaccumulation. Finally, we consider possible mechanisms that account forβ-amyloidosis progression through synaptically linked regions.

scholarly journals Neural Correlates of the Inverse Base Rate Effect

2019 ◽  
Author(s):  
Angus Inkster ◽  
Fraser Milton ◽  
Charlotte E R Edmunds ◽  
Abdelmalek Benattayallah ◽  
Andy Wills
Keyword(s):  
Prediction Error ◽  
Base Rate ◽  
Rate Effect ◽  
Anterior Cingulate ◽  
Brain Areas ◽  
Stimulus Compound ◽  
Predictive Learning ◽  
Fmri Study ◽  
Dorsolateral Prefrontal ◽  
The Difference

The Inverse Base Rate effect (IBRE; Medin & Edelson, 1988) is a non-rational behavioral phenomenon in predictive learning. Canonically, participants learn that the AB stimulus compound leads to one outcome and that AC leads to another outcome, with AB being presented three times as often as AC. When subsequently presented with BC, the outcome associated with AC is selected preferentially, in opposition to the underlying base rates of the outcomes. While many potential explanations of the effect exist, an error-driven learning account (Kruschke, 2001b) is particularly influential. A key component of this account is prediction error, a concept previously linked to a number of brain areas including the anterior cingulate, the striatum and the dorsolateral prefrontal cortex. The present study is the first fMRI study to directly examine the IBRE. Activations were noted in the brain areas linked to prediction error, including the caudate body, the anterior cingulate cortex and the middle frontal gyrus. Analysing the difference in activations for singular key stimuli (B and C), as well as frequency matched controls, supports the predictions made by the error-driven learning account.

scholarly journals Neural Mechanisms in Eating Behaviors: A Pilot fMRI Study of Emotional Processing

2020 ◽  
Vol 17 (3) ◽  
pp. 225-236 ◽  
Author(s):  
Rosa M. Molina-Ruiz ◽  
T. García-Saiz ◽  
Jeffrey C.L. Looi ◽  
E. Via Virgili ◽  
M. Rincón Zamorano ◽  
...  
Keyword(s):  
Emotional Processing ◽  
Eating Behaviors ◽  
Brain Area ◽  
Self Control ◽  
Women Patients ◽  
Brain Areas ◽  
Fmri Study ◽  
Neural Substrate ◽  
Dorsolateral Prefrontal ◽  
Functional Relevance

Objective Emotional processing dysfunction evident in eating disorders (ED) such as anorexia nervosa (AN) and bulimia nervosa (BN), is considered relevant to the development and maintenance of these disorders. The purpose of the current functional magnetic resonance imaging (fMRI) study was to pilot a comparison of the activity of the fronto-limbic and fronto-striatal brain areas during an emotion processing task in persons with ED.Methods 24 women patients with ED were scanned, while showing emotionally stimulating (pleasant, unpleasant) and neutral images from the International Affective Picture System (IAPS).Results During the pleasant condition, significant differences in Dorsolateral Prefrontal Cortex (DLPFC) activations were found with AN participants presenting greater activation compared to BN and ED comorbid groups (EDc) and healthy controls also showing greater activation of this brain area compared to BN and EDc. Left putamen was less activated in EDc compared to both controls (C) and AN. During the unpleasant condition, AN participants showed hyperactivation of the Orbito-frontal Cortex (OFC) when compared to EDc.Conclusion This study highlights the potential functional relevance of brain areas that have been associated with self-control. These findings should help advance understanding the neural substrate of ED, though they should be considered as preliminary and be cautiously interpreted.

scholarly journals Interaction between neuronal encoding and population dynamics during categorization task switching in parietal cortex

2020 ◽  
Author(s):  
Krithika Mohan ◽  
Oliver Zhu ◽  
David Freedman
Keyword(s):  
Parietal Cortex ◽  
Cognitive Process ◽  
Neural Encoding ◽  
Short Term ◽  
Brain Areas ◽  
Categorization Task ◽  
Attractor Dynamics ◽  
Feature Encoding ◽  
The One ◽  
Neuronal Encoding

AbstractPrimates excel at categorization, a cognitive process for assigning stimuli into behaviorally relevant groups. Categories are encoded in multiple brain areas and tasks, yet it remains unclear how neural encoding and dynamics support cognitive tasks with different demands. We recorded from parietal cortex during flexible switching between categorization tasks with distinct cognitive and motor demands, and also studied recurrent neural networks (RNNs) trained on the same tasks. In the one-interval categorization task (OIC), monkeys rapidly reported their decisions with a saccade. In the delayed match-to-category (DMC) task, monkeys decided whether sequentially presented stimuli were categorical matches. Neuronal category encoding generalized across tasks, but categorical encoding was more binary-like in the DMC task and more graded in the OIC task. Furthermore, analysis of the trained RNNs supports the hypothesis that binary-like encoding in the DMC task arises through compression of graded feature encoding by population attractor dynamics underlying short-term working memory.

Abstract 82: In Vivo Memri Reveals Persistent Activation of the Pvn by an Acute Systemic Angiotensin Ii Injection

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Jasenka Zubcevic ◽  
Pablo D Perez ◽  
Jessica Marulanda Carvajal ◽  
Mohan K Raizada ◽  
Marcelo Febo
Keyword(s):  
Neuronal Activity ◽  
Spontaneously Hypertensive Rat ◽  
Pressor Response ◽  
Neuronal Response ◽  
Neuronal Activation ◽  
Brain Areas ◽  
Neurogenic Hypertension ◽  
Wistar Kyoto ◽  
The Brain

Introduction: An overactive brain renin-angiotensin system is a major factor in the establishment of neurogenic hypertension in the spontaneously hypertensive rat (SHR). However, there is no concrete evidence to indicate that this is associated with enhanced neuronal activity in the brain. The objective here was to use the MRI to establish the effect of ANGII on neuronal activity in the autonomic brain areas. We propose that a single ANGII injection will cause a long-lasting neuronal response in the autonomic brain areas, which will be exaggerated in the SHR. Methods: In vivo basal and ANGII-evoked neuronal activity was measured in the Wistar-Kyoto (WKY) rat and the SHR using manganese-enhanced MRI (MEMRI) at 4.7Tesla. Rats were treated with manganese chloride (MnCl 2 30 mM solution, i.p .;16-20 hrs prior to the MRI), which labels active neurons. T 1 -weighted images were obtained 16-20 hrs after a single ANGII injection (0.32μg/kg i.p.). Coronal slice scans (caudally from end of the cerebellum towards the hypothalamus) were processed using itkSNAP, and data analyzed for normalized signal intensity. Results: Acute ANGII injection caused an immediate pressor response in the WKY (ΔSBP=∼20mmHg), normalizing within 2 hours. Despite this, ANGII evoked a persistent PVN neuronal activation, which was elevated by 22±4% in the WKY, and by 187±45% in the PVN of SHR. As a result, there was a ∼8.5fold increase in the ANGII-dependent neuronal activity in the PVN of SHR compared to WKY. Furthermore, there was a ∼2.5fold decrease in the NTS neuronal activity in the SHR compared to WKY. Conclusion: The present study shows for the first time the correlation between ANGII and autonomic neuronal activation. Even a single systemic ANGII injection results in a lasting effect on the brain. This is particularly apparent in the SHR, which exhibited an exaggerated neuronal response to the ANGII stimulus, reflected in the elevated PVN neuronal activation corresponding to the enhanced sympathetic drive, and in the depressed NTS activation corresponding to the dysfunction in the barorereflex processing. Thus, repeated pro-hypertensive stimuli in the autonomic brain areas may lead to pre-sympathetic neuronal plasticity, resulting in heightened sympathetic drive and hypertension.

Imaging Imagination: Brain Scanning of the Imagined Future

2007 ◽  
Author(s):  
MORTEN L. KRINGELBACH ◽  
JOHN G. GEAKE
Keyword(s):  
Prefrontal Cortex ◽  
Real World ◽  
Orbitofrontal Cortex ◽  
Counterfactual Thinking ◽  
Brain Areas ◽  
Functional Roles ◽  
Selection Processes ◽  
Dorsolateral Prefrontal ◽  
Interacting Networks ◽  
The Brain

Imagination is believed to be made-up of two components. The first one suggests that acts of imagination engage similar networks in the brain to those used for motor and sensory processing during interactions with the real world. The second component purports that the selection processes used in the subcomponents of imagination such as mindedness, anticipation, and counterfactual thinking rely on the subcortical and cortical networks of the brain which consist of components such as the cerebellum, orbitofrontal cortex, dorsolateral prefrontal cortex, and cingulate cortex. This chapter reviews the emerging literature on neuroimaging of various components of imagination. Imaging and other neuroscientific techniques offer various possibilities in the architecture of the imaginative mind. It shows how the neural bases of the imaginative activities are organized. Imaginative processes are distributed activities which recruit several brain areas and networks. These complex relations within and between these various networks are illustrated by the Dynamic Workspace Hypothesis. However it is expected that the precise functional roles of these interacting networks can be accurately defined through the advent of brain scanning and neuroimaging, particularly through the technical breakthroughs imagined in a Coda.

Monkey Prefrontal Neuronal Activity Coding the Forthcoming Saccade in an Oculomotor Delayed Matching-to-Sample Task

1998 ◽  
Vol 79 (1) ◽  
pp. 322-333 ◽  
Author(s):  
Ryohei Hasegawa ◽  
Toshiyuki Sawaguchi ◽  
Kisou Kubota
Keyword(s):  
Neuronal Activity ◽  
Saccadic Eye Movements ◽  
Matching To Sample ◽  
Delayed Matching ◽  
Delayed Matching To Sample ◽  
Geometric Figures ◽  
Significant Difference ◽  
Dorsolateral Prefrontal ◽  
Saccade Direction ◽  
Selection Of

Hasegawa, Ryohei, Toshiyuki Sawaguchi, and Kisou Kubota. Monkey prefrontal neuronal activity coding the forthcoming saccade in an oculomotor delayed matching-to-sample task. J. Neurophysiol. 79: 322–333, 1998. To determine the role of the dorsolateral prefrontal cortex (PFC) in the selection of memory-guided saccadic eye movements, we recorded the activities of PFC neurons while macaque monkeys performed an oculomotor delayed matching-to-sample task. The task was designed to dissociate motor factors from visual factors in the selection and retention of the direction of the forthcoming saccade during delay periods after the visual cue but before the GO signal was presented. While the monkey fixated on a central fixation spot (FX period, 1 s), a sample cue (1 of 4 geometric figures) and a matching cue composed of two geometric figures were presented in succession (SC and MC periods, respectively, 0.5 s) with a brief delay (D1 period, 1 or 1.5 s). After another delay (D2 period, 1.5 s), the monkey made a saccade (GO period, <0.5 s) toward one of four locations (the goal) that had been indicated by the combination of the sample and matching cues in the MC period. We recorded the activities of 224 neurons in the periprincipal sulcal area of 3 hemispheres of 2 monkeys. Sixty-five neurons (29%) showed a significant increase in activity during the D2 period. Some of these also responded during other phases of the task (SC period, n = 32; D1, 22; MC, 53; GO, 47). Some of the activity during the D2(52/65, 80%) and GO (40/47, 85%) periods was associated with the direction of the forthcoming saccade (“direction selective”). Although most MC-period activities of D2 neurons were direction selective (38/53, 73%), a fraction of them (14/38) was also affected by both saccade direction and matching cue pattern. To compare quantitatively the contribution of motor (saccade direction) and visual (matching-cue pattern) factors to the activity of D2 neurons, we calculated directional and visual dependency indices (DDI and VDI) for each of the three periods (MC, D2, and GO). In both the D2 and GO periods, D2 neurons with high DDI values and low VDI values predominated. In the MC period, however, there was no significant difference between the distributions of DDI and VDI values. These findings suggest that PFC neurons store the direction of memory-guided saccades during a delay period before eye movement and that the same neurons may be involved in the decision-making process that underlies the selection of the saccade direction during the MC period.

scholarly journals Attention can be subdivided into neurobiological components corresponding to distinct behavioral effects

2019 ◽  
Vol 116 (52) ◽  
pp. 26187-26194 ◽  
Author(s):  
Thomas Zhihao Luo ◽  
John H. R. Maunsell
Keyword(s):  
Neuronal Activity ◽  
Signal Detection Theory ◽  
Behavioral Changes ◽  
Behavioral Effects ◽  
Biological Mechanisms ◽  
Brain Areas ◽  
Neurophysiological Studies ◽  
Complex Term ◽  
The Many ◽  
The Brain

Attention is a common but highly complex term associated with a large number of distinct behavioral and perceptual phenomena. In the brain, attention-related changes in neuronal activity are observed in widespread structures. The many distinct behavioral and neuronal phenomena related to attention suggest that it might be subdivided into components corresponding to distinct biological mechanisms. Recent neurophysiological studies in monkeys have isolated behavioral changes related to attention along the 2 indices of signal detection theory and found that these 2 behavioral changes are associated with distinct neuronal changes in different brain areas. These results support the view that attention is made up of distinct neurobiological mechanisms.

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