scholarly journals Neuronal variability in orbitofrontal cortex during economic decisions

2015 ◽  
Vol 114 (3) ◽  
pp. 1367-1381 ◽  
Author(s):  
Katherine E. Conen ◽  
Camillo Padoa-Schioppa
Keyword(s):  
Orbitofrontal Cortex ◽  
Rhesus Monkeys ◽  
Decision Model ◽  
Quantitative Information ◽  
Neuronal Population ◽  
Lower Strength ◽  
Economic Decisions ◽  
Stochastic Fluctuations ◽  
Mathematical Relation ◽  
Cortical Regions

Neuroeconomic models assume that economic decisions are based on the activity of offer value cells in the orbitofrontal cortex (OFC), but testing this assertion has proven difficult. In principle, the decision made on a given trial should correlate with the stochastic fluctuations of these cells. However, this correlation, measured as a choice probability (CP), is small. Importantly, a neuron's CP reflects not only its individual contribution to the decision (termed readout weight), but also the intensity and the structure of correlated variability across the neuronal population (termed noise correlation). A precise mathematical relation between CPs, noise correlations, and readout weights was recently derived by Haefner and colleagues (Haefner RM, Gerwinn S, Macke JH, Bethge M. Nat Neurosci 16: 235–242, 2013) for a linear decision model. In this framework, concurrent measurements of noise correlations and CPs can provide quantitative information on how a population of cells contributes to a decision. Here we examined neuronal variability in the OFC of rhesus monkeys during economic decisions. Noise correlations had similar structure but considerably lower strength compared with those typically measured in sensory areas during perceptual decisions. In contrast, variability in the activity of individual cells was high and comparable to that recorded in other cortical regions. Simulation analyses based on Haefner's equation showed that noise correlations measured in the OFC combined with a plausible readout of offer value cells reproduced the experimental measures of CPs. In other words, the results obtained for noise correlations and those obtained for CPs taken together support the hypothesis that economic decisions are primarily based on the activity of offer value cells.

scholarly journals Neuronal origins of biases in economic choices under sequential offers

2021 ◽  
Author(s):  
Weikang Shi ◽  
Sebastien Ballesta ◽  
Camillo Padoa-Schioppa
Keyword(s):  
Orbitofrontal Cortex ◽  
Rhesus Monkeys ◽  
Choice Behavior ◽  
Neural Mechanisms ◽  
Choice Accuracy ◽  
Bias Analysis ◽  
Economic Decisions ◽  
Economic Choices ◽  
Shed Light

Economic choices are characterized by a variety of biases. Understanding their origins is a long-term goal for neuroeconomics, but progress on this front has been limited. Here we examined choice biases observed when two goods are offered sequentially. In the experiments, rhesus monkeys chose between different juices offered simultaneously or in sequence. Choices under sequential offers were less accurate (higher variability). They were also biased in favor of the second offer (order bias) and in favor of the preferred juice (preference bias). Analysis of neuronal activity recorded in orbitofrontal cortex revealed that these phenomena emerged at different computational stages. The lower choice accuracy reflected weaker offer value signals (valuation stage), the order bias emerged during value comparison (decision stage), and the preference bias emerged late in the trial (post-comparison). Our approach, leveraging recent notions on the neural mechanisms of economic decisions, may shed light on other aspects of choice behavior.

scholarly journals Interacting roles of lateral and medial Orbitofrontal cortex in decision-making and learning : A system-level computational model

2019 ◽  
Author(s):  
Bhargav Teja Nallapu ◽  
Frédéric Alexandre
Keyword(s):  
Decision Making ◽  
Prefrontal Cortex ◽  
Computational Model ◽  
Orbitofrontal Cortex ◽  
Temporal Dynamics ◽  
System Level ◽  
Interacting Networks ◽  
Cortical Regions ◽  
Experimental Findings

AbstractIn the context of flexible and adaptive animal behavior, the orbitofrontal cortex (OFC) is found to be one of the crucial regions in the prefrontal cortex (PFC) influencing the downstream processes of decision-making and learning in the sub-cortical regions. Although OFC has been implicated to be important in a variety of related behavioral processes, the exact mechanisms are unclear, through which the OFC encodes or processes information related to decision-making and learning. Here, we propose a systems-level view of the OFC, positioning it at the nexus of sub-cortical systems and other prefrontal regions. Particularly we focus on one of the most recent implications of neuroscientific evidences regarding the OFC - possible functional dissociation between two of its sub-regions : lateral and medial. We present a system-level computational model of decision-making and learning involving the two sub-regions taking into account their individual roles as commonly implicated in neuroscientific studies. We emphasize on the role of the interactions between the sub-regions within the OFC as well as the role of other sub-cortical structures which form a network with them. We leverage well-known computational architecture of thalamo-cortical basal ganglia loops, accounting for recent experimental findings on monkeys with lateral and medial OFC lesions, performing a 3-arm bandit task. First we replicate the seemingly dissociate effects of lesions to lateral and medial OFC during decision-making as a function of value-difference of the presented options. Further we demonstrate and argue that such an effect is not necessarily due to the dissociate roles of both the subregions, but rather a result of complex temporal dynamics between the interacting networks in which they are involved.Author summaryWe first highlight the role of the Orbitofrontal Cortex (OFC) in value-based decision making and goal-directed behavior in primates. We establish the position of OFC at the intersection of cortical mechanisms and thalamo-basal ganglial circuits. In order to understand possible mechanisms through which the OFC exerts emotional control over behavior, among several other possibilities, we consider the case of dissociate roles of two of its topographical subregions - lateral and medial parts of OFC. We gather predominant roles of each of these sub-regions as suggested by numerous experimental evidences in the form of a system-level computational model that is based on existing neuronal architectures. We argue that besides possible dissociation, there could be possible interaction of these sub-regions within themselves and through other sub-cortical structures, in distinct mechanisms of choice and learning. The computational framework described accounts for experimental data and can be extended to more comprehensive detail of representations required to understand the processes of decision-making, learning and the role of OFC and subsequently the regions of prefrontal cortex in general.

scholarly journals Values Encoded in Orbitofrontal Cortex Are Causally Related to Economic Choices

2020 ◽  
Author(s):  
Sébastien Ballesta ◽  
Weikang Shi ◽  
Katherine E. Conen ◽  
Camillo Padoa-Schioppa
Keyword(s):  
Electrical Stimulation ◽  
Neuronal Activity ◽  
Orbitofrontal Cortex ◽  
Rhesus Monkeys ◽  
Fundamental Issue ◽  
High Current ◽  
Neural Processes ◽  
Economic Choices ◽  
The Brain

AbstractIt has long been hypothesized that economic choices rely on the assignment and comparison of subjective values. Indeed, when agents make decisions, neurons in orbitofrontal cortex encode the values of offered and chosen goods. Moreover, neuronal activity in this area suggests the formation of a decision. However, it is unclear whether these neural processes are causally related to choices. More generally, the evidence linking economic choices to value signals in the brain remains correlational. We address this fundamental issue using electrical stimulation in rhesus monkeys. We show that suitable currents bias choices by increasing the value of individual offers. Furthermore, high-current stimulation disrupts both the computation and the comparison of subjective values. These results demonstrate that values encoded in orbitofrontal cortex are causal to economic choices.

scholarly journals Contributions of different prefrontal cortical regions to abstract rule acquisition and reversal in monkeys

2017 ◽  
Author(s):  
Giancarlo La Camera ◽  
Sebastien Bouret ◽  
Barry J. Richmond
Keyword(s):  
Orbitofrontal Cortex ◽  
Brain Regions ◽  
Abstract Concept ◽  
Abstract Concepts ◽  
Prefrontal Cortical ◽  
Rule Acquisition ◽  
Learning Rules ◽  
Association Task ◽  
Abstract Rule ◽  
Cortical Regions

AbstractThe ability to learn and follow abstract rules relies on intact prefrontal regions including the lateral prefrontal cortex (LPFC) and the orbitofrontal cortex (OFC). Here, we investigate the specific roles of these brain regions in learning rules that depend critically on the formation of abstract concepts as opposed to simpler input-output associations. To this aim, we tested monkeys with bilateral removals of either LPFC or OFC on a rapidly learned task requiring the formation of the abstract concept of same vs. different. While monkeys with OFC removals were significantly slower than controls at both acquiring and reversing the concept-based rule, monkeys with LPFC removals were not impaired in acquiring the task, but were significantly slower at rule reversal. Neither group was impaired in the acquisition or reversal of a delayed visual cue-outcome association task without a concept-based rule. These results suggest that OFC is essential for the implementation of a concept-based rule, whereas LPFC seems essential for its modification once established.

scholarly journals Interneuron Types and Their Circuits in the Basolateral Amygdala

2021 ◽  
Vol 15 ◽  
Author(s):  
Norbert Hájos
Keyword(s):  
Basolateral Amygdala ◽  
Cell Types ◽  
Neuronal Population ◽  
Entry Site ◽  
Different Types ◽  
Network Operation ◽  
Developmental Characteristics ◽  
Cortical Regions ◽  
Multisensory Information

The basolateral amygdala (BLA) is a cortical structure based on its cell types, connectivity features, and developmental characteristics. This part of the amygdala is considered to be the main entry site of processed and multisensory information delivered via cortical and thalamic afferents. Although GABAergic inhibitory cells in the BLA comprise only 20% of the entire neuronal population, they provide essential control over proper network operation. Previous studies have uncovered that GABAergic cells in the basolateral amygdala are as diverse as those present in other cortical regions, including the hippocampus and neocortex. To understand the role of inhibitory cells in various amygdala functions, we need to reveal the connectivity and input-output features of the different types of GABAergic cells. Here, I review the recent achievements in uncovering the diversity of GABAergic cells in the basolateral amygdala with a specific focus on the microcircuit organization of these inhibitory cells.

scholarly journals Value signals in orbitofrontal cortex predict economic decisions on a trial-to-trial basis

2021 ◽  
Author(s):  
Vincent B. McGinty ◽  
Shira M. Lupkin
Keyword(s):  
Neural Activity ◽  
Orbitofrontal Cortex ◽  
Population Level ◽  
Weighted Sum ◽  
Decision Behavior ◽  
Economic Decisions ◽  
Trial Basis ◽  
Individual Value ◽  
Value Coding ◽  
First Time

ABSTRACTNeuroeconomics seeks to explain how neural activity contributes to decision behavior. For value-based decisions, the primate orbitofrontal cortex (OFC) is thought to have a key role; however, the mechanism by which single OFC cells contribute to choices is still unclear. Here, we show for the first time a trial-to-trial relationship between choices and population-level value representations in OFC, defined by the weighted sum of activity from many individual value-coding neurons.

Representation of Umami Taste in the Human Brain

2003 ◽  
Vol 90 (1) ◽  
pp. 313-319 ◽  
Author(s):  
I.E.T. de Araujo ◽  
M. L. Kringelbach ◽  
E. T. Rolls ◽  
P. Hobden
Keyword(s):  
Orbitofrontal Cortex ◽  
Anterior Part ◽  
Monosodium Glutamate ◽  
Blood Oxygenation ◽  
Anterior Cingulate ◽  
Bold Signal ◽  
Taste System ◽  
Umami Taste ◽  
Oxygenation Level ◽  
Cortical Regions

Umami taste stimuli, of which an exemplar is monosodium glutamate (MSG) and which capture what is described as the taste of protein, were shown using functional MRI (fMRI) to activate similar cortical regions of the human taste system to those activated by a prototypical taste stimulus, glucose. These taste regions included the insular/opercular cortex and the caudolateral orbitofrontal cortex. A part of the rostral anterior cingulate cortex (ACC) was also activated. When the nucleotide 0.005 M inosine 5′-monophosphate (IMP) was added to MSG (0.05 M), the blood oxygenation-level dependent (BOLD) signal in an anterior part of the orbitofrontal cortex showed supralinear additivity; this may reflect the subjective enhancement of umami taste that has been described when IMP is added to MSG. These results extend to humans previous studies in macaques showing that single neurons in these taste cortical areas can be tuned to umami stimuli.

Remitted major depression is related to increased functional coupling between ventral striatum and cortical regions in resting state fMRI

2011 ◽  
Vol 26 (S2) ◽  
pp. 948-948 ◽  
Author(s):  
G. Pail ◽  
C. Scharinger ◽  
K. Kalcher ◽  
W. Huf ◽  
R. Boubela ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Orbitofrontal Cortex ◽  
Resting State ◽  
Ventral Striatum ◽  
Resting State Fmri ◽  
Anterior Cingulate ◽  
Functional Coupling ◽  
Healthy Controls ◽  
Full Remission ◽  
Cortical Regions

IntroductionDysfunction in the basal ganglia has been related to impaired reward processing and anhedonia, a core symptom of Major Depressive Disorder (MDD). In particular, the ventral striatum including the nucleus accumbens is increasingly implicated in the pathophysiology of MDD, but evidence for a specific role during episodes of full remission is lacking so far.ObjectivesTo investigate functional connectivity patterns of resting-state activity in patients in the remitted phase of MDD (rMDD).AimsTo determine whether rMDD is related to disruptions of functional coupling between the ventral striatum and cortical regions.MethodsForty-three remitted depressed patients and thirty-five healthy controls were recruited at Medical University of Vienna, Vienna, Austria, and performed a six minute resting-state fMRI scan. Seed time series were extracted from the preprocessed data using individual masks for ventral striatum and correlated with all nodes in a surface based analysis using FreeSurfer, AFNI and SUMA. The resulting correlation coefficients were then Fishertransformed, group results were determined by comparing group mean smoothed z-scores with a two-sample ttest.ResultsIncreased resting-state functional connectivity was revealed between ventral striatum (seed region) and anterior cingulate cortex as well as orbitofrontal cortex in the rMDD group compared to healthy controls.ConclusionsOur preliminary data is in accordance with the idea that increased functional coupling between the ventral striatum and two major emotion processing regions, the anterior cingulate cortex and the orbitofrontal cortex, may represent a neural mechanism contributing to the maintenance of full remission of MDD.

scholarly journals Effects of Attention and Emotion on Repetition Priming and Their Modulation by Cholinergic Enhancement

2003 ◽  
Vol 90 (2) ◽  
pp. 1171-1181 ◽  
Author(s):  
Paul Bentley ◽  
Patrik Vuilleumier ◽  
Christiane M. Thiel ◽  
Jon Driver ◽  
Raymond J. Dolan
Keyword(s):  
Orbitofrontal Cortex ◽  
Repetition Priming ◽  
Occipital Cortex ◽  
Repetition Effects ◽  
Emotional Faces ◽  
Emotional Interaction ◽  
Neural Signature ◽  
Cortical Regions ◽  
Task Irrelevant ◽  
Or Task

We examined whether behavioral and neural effects of repeating faces are modulated by independent factors of selective attention, emotion, and cholinergic enhancement, during functional MRI. Face repetition occurred either between task-relevant (spatially attended) or task-irrelevant (unattended) stimuli; faces could be fearful or neutral; subjects received either placebo or physostigmine. Under placebo, a reaction time advantage occurred with repetition (i.e., priming) that did not differ between levels of attention, but was attenuated with emotion. Inferior temporo-occipital cortex demonstrated repetition decreases to both attended and unattended faces, and showed either equivalent or greater repetition decreases with emotional compared with neutral faces. By contrast, repetition decreases were attenuated for emotional relative to neutral faces in lateral orbitofrontal cortex. These results distinguish automatic repetition effects in sensory cortical regions from repetition effects modulated by emotion in orbitofrontal cortex, which parallel behavioral effects. Under physostigmine, unlike placebo, behavioral repetition effects were seen selectively for attended faces only, whereas emotional faces no longer impaired priming. Physostigmine enhanced repetition decreases in inferior occipital cortex selectively for attended faces, and reversed the emotional interaction with repetition in lateral orbitofrontal cortex. Thus we show that cholinergic enhancement both augments a neural signature of priming and modulates the effects of attention and emotion on behavioral and neural consequences of repetition.

Cortical Processing of Pitch: Excitation or Inhibition?

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P100-P100 ◽  
Author(s):  
Robert L Harris ◽  
Subrati Nagina ◽  
Steve John Jones
Keyword(s):  
Auditory Processing ◽  
Auditory Evoked Potentials ◽  
Random Noise ◽  
Neuronal Population ◽  
Small Degree ◽  
Complex Sounds ◽  
Short Intervals ◽  
Frequency Representation ◽  
Cortical Regions ◽  
Onset Response

Problem Although tonotopicity provides frequency representation, it does not provide an explicit representation of pitch for complex sounds. For conventional stimuli, it is not possible to vary pitch without varying the spectrum of the sound. It is possible using a regular interval noise(RIN). RIN isolates the neural response associated with the perception of pitch. Several recent studies have identified a specific region in the auditory cortex that contains a cortical representation of pitch. Methods RIN auditory evoked potentials to: 1) determine over what range of temporal periods of RIN evoked a pitch onset response (POR); 2) determine how many cycles of RIN are required for its detection; 3) investigate inter-hemispheric predominance of the POR; 4) investigate if different periodicities are represented in different cortical regions; 5) determine if the degree of refractoriness of the POR is similar when the same pitches occur at regular, short intervals, as when infrequent occurrences of a particular pitch are interspersed with other pitches at the same short intervals. Results 1) a pitch onset response is evoked over the whole range of periodicities giving rise to a sense of musical pitch; 2) at most periodicities less than 2 cycles of RIN are required in order to evoke a response; 3) no marked interhemispheric differences were revealed; 4) evidence for a “periodotopic” distribution of responses was inconclusive; 5) the refractory properties of the response mainly suggested a common neuronal population, but with small degree of pitch specificity. Conclusion There is a striking apparent disparity between human studies, which suggest a large increase in both metabolic and electrophysiological activity when random noise becomes periodic, at whatever pitch, and the animal literature which suggests only a few pitch-selective neurons are excited. We propose a model that explains the observed differences: that the large neuronal population response represents widespread inhibition. Significance The investigation of patients with auditory processing disorders.

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