scholarly journals Primate prefrontal neurons signal economic risk derived from the statistics of recent reward experience

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Fabian Grabenhorst ◽  
Ken-Ichiro Tsutsui ◽  
Shunsuke Kobayashi ◽  
Wolfram Schultz
Keyword(s):  
Dorsolateral Prefrontal Cortex ◽  
Choice Task ◽  
Support Vector ◽  
Probabilistic Choice ◽  
Economic Decisions ◽  
Decision Variables ◽  
Dorsolateral Prefrontal ◽  
Process Risk ◽  
The Brain ◽  
Statistical Variance

Risk derives from the variation of rewards and governs economic decisions, yet how the brain calculates risk from the frequency of experienced events, rather than from explicit risk-descriptive cues, remains unclear. Here, we investigated whether neurons in dorsolateral prefrontal cortex process risk derived from reward experience. Monkeys performed in a probabilistic choice task in which the statistical variance of experienced rewards evolved continually. During these choices, prefrontal neurons signaled the reward-variance associated with specific objects (‘object risk’) or actions (‘action risk’). Crucially, risk was not derived from explicit, risk-descriptive cues but calculated internally from the variance of recently experienced rewards. Support-vector-machine decoding demonstrated accurate neuronal risk discrimination. Within trials, neuronal signals transitioned from experienced reward to risk (risk updating) and from risk to upcoming choice (choice computation). Thus, prefrontal neurons encode the statistical variance of recently experienced rewards, complying with formal decision variables of object risk and action risk.

scholarly journals Reducing future fears by suppressing the brain mechanisms underlying episodic simulation

2016 ◽  
Vol 113 (52) ◽  
pp. E8492-E8501 ◽  
Author(s):  
Roland G. Benoit ◽  
Daniel J. Davies ◽  
Michael C. Anderson
Keyword(s):  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Ventromedial Prefrontal Cortex ◽  
Episodic Simulation ◽  
Dorsolateral Prefrontal ◽  
Future Events ◽  
The Right ◽  
Development Of Anxiety ◽  
The Brain

Imagining future events conveys adaptive benefits, yet recurrent simulations of feared situations may help to maintain anxiety. In two studies, we tested the hypothesis that people can attenuate future fears by suppressing anticipatory simulations of dreaded events. Participants repeatedly imagined upsetting episodes that they feared might happen to them and suppressed imaginings of other such events. Suppressing imagination engaged the right dorsolateral prefrontal cortex, which modulated activation in the hippocampus and in the ventromedial prefrontal cortex (vmPFC). Consistent with the role of the vmPFC in providing access to details that are typical for an event, stronger inhibition of this region was associated with greater forgetting of such details. Suppression further hindered participants’ ability to later freely envision suppressed episodes. Critically, it also reduced feelings of apprehensiveness about the feared scenario, and individuals who were particularly successful at down-regulating fears were also less trait-anxious. Attenuating apprehensiveness by suppressing simulations of feared events may thus be an effective coping strategy, suggesting that a deficiency in this mechanism could contribute to the development of anxiety.

Altruism from the Perspective of the Social Neurosciences

e-Neuroforum ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. A11-A18
Author(s):  
Sabine Windmann ◽  
Grit Hein
Keyword(s):  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Anterior Insula ◽  
Future Research ◽  
Levels Of Explanation ◽  
Temporoparietal Junction ◽  
The Social ◽  
Dorsolateral Prefrontal ◽  
The Brain ◽  
Research Studies

Abstract Altruism is a puzzling phenomenon, especially for Biology and Economics. Why do individuals reduce their chances to provide some of the resources they own to others? The answer to this question can be sought at ultimate or proximate levels of explanation. The Social Neurosciences attempt to specify the brain mechanisms that drive humans to act altruistically, in assuming that overtly identical behaviours can be driven by different motives. The research has shown that activations and functional connectivities of the Anterior Insula and the Temporoparietal Junction play specific roles in empathetic versus strategic forms of altruism, whereas the dorsolateral prefrontal cortex, among other regions, is involved in norm-oriented punitive forms of altruism. Future research studies could focus on the processing of ambiguity and conflict in pursuit of altruistic intentions.

Dissociation of Spatial-, Object-, and Sound-Coding Neurons in the Mediodorsal Nucleus of the Primate Thalamus

2003 ◽  
Vol 89 (2) ◽  
pp. 1067-1077 ◽  
Author(s):  
Ikuo Tanibuchi ◽  
Patricia S. Goldman-Rakic
Keyword(s):  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Single Neuron ◽  
Neuronal Responses ◽  
Mediodorsal Nucleus ◽  
Sound Coding ◽  
Spatial Tasks ◽  
Dorsolateral Prefrontal ◽  
Information Segregation ◽  
The Brain

The mediodorsal nucleus (MD) is the thalamic gateway to the prefrontal cortex, an area of the brain associated with spatial and object working memory functions. We have recorded single-neuron activities from the MD nucleus in monkeys trained to perform spatial tasks with peripheral visual stimuli and a nonspatial task with foveally presented pictures of objects and faces—tasks identical to those we have previously used to map regional specializations in the dorso- and ventro-lateral prefrontal cortex, respectively. We found that MD neurons exhibited categorical specificity—either responding selectively to locations in the spatial tasks or preferentially to specific representations of faces and objects in the nonspatial task. Spatially tuned neurons were located in parts of the MD connected with the dorsolateral prefrontal cortex while neurons responding to the identity of stimuli mainly occupied more ventral positions in the nucleus that has its connections with the inferior prefrontal convexity. Neuronal responses to auditory stimuli were also examined, and vocalization sensitive neurons were found in more posterior portions of the MD. We conclude that MD neurons are dissociable by their spatial and nonspatial coding properties in line with their cortical connections and that the principle of information segregation in cortico-cortical pathways extends to the “association” nuclei of the thalamus.

Neuropsychological correlates of syndromes in schizophrenia

1997 ◽  
Vol 170 (2) ◽  
pp. 134-139 ◽  
Author(s):  
Ross M. G. Norman ◽  
A. K. Malla ◽  
S. L. Morrison-Stewart ◽  
E. Helmes ◽  
P. C. Williamson ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Temporal Lobe ◽  
Neuropsychological Tests ◽  
Dorsolateral Prefrontal Cortex ◽  
Neuropsychological Performance ◽  
Left Temporal Lobe ◽  
Impaired Performance ◽  
Dorsolateral Prefrontal ◽  
Reality Distortion ◽  
The Brain

BackgroundOn the basis of Liddle's three-syndrome model of schizophrenia, it was predicted that: (1) symptoms of psychomotor poverty would be particularly correlated with impaired performance on neuropsychological tests likely to reflect functioning of the dorsolateral prefrontal cortex; (2) disorganisation would be particularly correlated with impaired performance on tests sensitive to medio-basal prefrontal functioning; and (3) reality distortion would be particularly correlated with measures sensitive to temporal lobe functioning.MethodThe above hypotheses were tested on 87 subjects with a confirmed diagnosis of schizophrenia. Patients' symptoms were scored for each of the three syndromes. Patients completed six neuropsychological tests designed to measure impairment in specific areas of the brain.ResultsThere was no support for the first two hypotheses. There was, however, evidence of a specific relationship between reality distortion and neuropsychological performance usually considered to be related to left temporal lobe functioning.ConclusionsAlthough not directly supporting the first two hypotheses; the results are, in general, consistent with there being different cortical-subcortical circuits associated with each of psychomotor poverty and disorganisation. Temporal lobe functioning appears to have particular significance for the reality distortion syndrome.

scholarly journals Methamphetamine-Triggered Neurotoxicity in Human Dorsolateral Prefrontal Cortex

2021 ◽  
Vol 10 ◽  
pp. 2016
Author(s):  
Ali Zare ◽  
Alireza Ghanbari ◽  
Mohammad Javad Hoseinpour ◽  
Mahdi Eskandarian Boroujeni ◽  
Alimohammad Alimohammadi ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Animal Studies ◽  
Molecular Mechanisms ◽  
Metabolic Activation ◽  
Neural Cells ◽  
Dorsolateral Prefrontal ◽  
The Central Nervous System ◽  
The Brain

Background: Methamphetamine (MA), is an extremely addictive stimulant that adversely affects the central nervous system. Accumulating evidence indicates that molecular mechanisms such as oxidative stress, apoptosis, and autophagy are involved in the toxicity of MA. Considering experimental animal studies exhibiting MA-induced neurotoxicity, the relevance of these findings needs to be evidently elucidated in human MA users. It is generally assumed that multiple chemical substances released in the brain following MA-induced metabolic activation are primary factors underlying damage of neural cells. Hence, this study aimed to investigate the role of autophagy and apoptosis as well as oxidative stress in the brain of postmortem MA-induced toxicity. Materials and Methods: In this study, we determine the gene expression of autophagy and apoptosis, including BECN1, MAP1ALC3, CASP8, TP53, and BAX genes in ten healthy controls and ten chronic users of MA postmortem dorsolateral prefrontal cortex (DLPFC) by real-time polymerase chain reaction. Also, we applied immunohistochemistry in formalin-fixed and paraffin-embedded human brain samples to analyze brain-derived neurotrophic factor (BDNF). Also, spectrophotometry was performed to measure glutathione (GSH) content. Results: The expression level of apoptotic and autophagic genes (BECN1, MAP1ALC3, CASP8, TP53, and BAX) were significantly elevated, while GSH content and BDNF showed substantial reductions in DLPFC of chronic MA users. Discussion: Our data showed that MA addiction provokes transduction pathways, namely apoptosis and autophagy, along with oxidative mechanisms in DLPFC. Also, MA induces multiple functional and structural perturbations in the brain, determining its toxicity and possibly contributing to neurotoxicity. [GMJ.2021;10:e2016]

Functional Stability of Dorsolateral Prefrontal Neurons

2004 ◽  
Vol 92 (2) ◽  
pp. 1042-1055 ◽  
Author(s):  
Paul A. Greenberg ◽  
Fraser A. W. Wilson
Keyword(s):  
Dorsolateral Prefrontal Cortex ◽  
Response Strength ◽  
Functional Stability ◽  
Firing Rates ◽  
Different Types ◽  
Dorsolateral Prefrontal ◽  
Cortical Regions ◽  
Response Timing ◽  
The Brain

Stable multiday recordings from the dorsolateral prefrontal cortex of 2 monkeys performing 2 Go/NoGo visual-discrimination tasks (one requiring well-learned responses, the other requiring learning) demonstrate that the majority of prefrontal neurons were “functionally stable”. Recordings were made using a series of removable microdrives, each implanted for 3–6 mo, housing independently mobile electrodes. Action potential waveforms of 94 neurons were stable over 2–9 days; 66/94 (70%) of these cells responded each day, 22/94 (23%) never responded significantly, and 6/94 (6%) responded one day but not the next. Of 66 responsive neurons, 55 were selective for either Go or NoGo trials, individual stimuli, or eye movements. This selectivity was functionally stable (i.e., maintained) for 46/55 neurons across all recording days. Functional stability was also noted in terms of response strength (baseline firing rates compared with poststimulation firing rates) and event-related response timing. Two neurons with consistent responses in familiar testing conditions responded flexibly when the monkeys learned to make correct responses to novel stimuli. We conclude that the majority of prefrontal neurons were functionally stable during the performance of well-learned tasks. Such stability may be a general property of prefrontal neurons, given that neurons with 4 different types of task selectivity were found to be functionally stable. Conceptually similar studies based on long-term recordings in other cortical regions reached similar conclusions, suggesting that neurons throughout the brain are functionally stable.

scholarly journals Neuroimaging ‘will to fight’ for sacred values: an empirical case study with supporters of an Al Qaeda associate

2019 ◽  
Vol 6 (6) ◽  
pp. 181585 ◽  
Author(s):  
Nafees Hamid ◽  
Clara Pretus ◽  
Scott Atran ◽  
Molly J. Crockett ◽  
Jeremy Ginges ◽  
...  
Keyword(s):  
Peer Influence ◽  
Dorsolateral Prefrontal Cortex ◽  
Brain Activity ◽  
Inferior Frontal Gyrus ◽  
Trade Offs ◽  
Sacred Values ◽  
Dorsolateral Prefrontal ◽  
Intergroup Conflicts ◽  
The Brain

Violent intergroup conflicts are often motivated by commitments to abstract ideals such as god or nation, so-called ‘sacred’ values that are insensitive to material trade-offs. There is scant knowledge of how the brain processes costly sacrifices for such cherished causes. We studied willingness to fight and die for sacred values using fMRI in Barcelona, Spain, among supporters of a radical Islamist group. We measured brain activity in radicalized individuals as they indicated their willingness to fight and die for sacred and non-sacred values, and as they reacted to peers' ratings for the same values. We observed diminished activity in dorsolateral prefrontal cortex (dlPFC), inferior frontal gyrus, and parietal cortex while conveying willingness to fight and die for sacred relative to non-sacred values—regions that have previously been implicated in calculating costs and consequences. An overlapping region of the dlPFC was active when viewing conflicting ratings of sacred values from peers, to the extent participants were sensitive to peer influence, suggesting that it is possible to induce flexibility in the way people defend sacred values. Our results cohere with a view that ‘devoted actors’ motivated by an extreme commitment towards sacred values rely on distinctive neurocognitve processes that can be identified.

scholarly journals Neuroplasticity of excitatory and inhibitory cortical circuits in schizophrenia

2009 ◽  
Vol 11 (3) ◽  
pp. 269-280
Keyword(s):  
Cognitive Processes ◽  
Dorsolateral Prefrontal Cortex ◽  
Neurodevelopmental Disorder ◽  
Disease Process ◽  
Underlying Disease ◽  
Cortical Circuits ◽  
Dorsolateral Prefrontal ◽  
Inhibitory Components ◽  
The Brain ◽  
Novel Therapeutic

Schizophrenia is a neurodevelopmental disorder characterized by deficits in cognitive processes mediated by the circuitry of the dorsolateral prefrontal cortex (DLPFC). These deficits are associated with a range of alterations in DLPFC circuitry, some of which reflect the pathology of the illness and others of which reflect the neuroplasticity of the brain in response to the underlying disease process. This article reviews disturbances in excitatory and inhibitory components of DLPFC circuitry from the perspective of developmental neuroplasticity and discusses their implications for the identification of novel therapeutic targets.

scholarly journals GABARAPL1 is differentially expressed in the brains of patients with psychotic disorders.

2020 ◽  
Author(s):  
Shahan Mamoor
Keyword(s):  
Prefrontal Cortex ◽  
Microarray Data ◽  
Dorsolateral Prefrontal Cortex ◽  
Psychotic Disorders ◽  
Differentially Expressed ◽  
Aminobutyric Acid ◽  
Receptor Associated Protein ◽  
Dorsolateral Prefrontal ◽  
Significant Gene ◽  
The Brain

We used public and published microarray data (1, 2) to identify the most significant gene expression changes in the brains of patients with psychotic disorders. We identified the 𝛄-aminobutyric acid receptor-associated protein-like 1 GABARAPL13 as differentially expressed in the dorsolateral prefrontal cortex of patients with schizophrenia as well as in the parvalbumin-positive layer 3 neurons of the dorsolateral prefrontal cortex of patients with schizophrenia and schizoaffective disorder. The brain tissues of patients with psychotic disorders expressed significantly lower levels of GABARAPL1 than that of non-affected control subjects. GABARAPL1 may be relevant to the biology of schizophrenia and related psychotic disorders.

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