scholarly journals Population coding of strategic variables during foraging in freely-moving macaques

2019 ◽  
Author(s):  
Neda Shahidi ◽  
Paul Schrater ◽  
Tony Wright ◽  
Xaq Pitkow ◽  
Valentin Dragoi
Keyword(s):  
Prefrontal Cortex ◽  
Time Course ◽  
Internal Representation ◽  
Population Coding ◽  
Neural Responses ◽  
Population Activity ◽  
Relevant Task ◽  
Dorsolateral Prefrontal ◽  
Future Outcomes ◽  
Foraging Task

Animals forage within their environment to extract valuable resources at lowest cost. Previous studies have suggested that animals simply maximize the current flow of reward without predicting the future outcomes of their actions and that this recent reward rate is represented in various brain areas. To test this, we devised a foraging task in which the relevant reward dynamics were hidden from the animal, and wirelessly record population activity in dorsolateral prefrontal cortex (dlPFC) while monkeys forage freely in their environment. We discover that their brains indeed contain predictions of future rewards and plans of their next actions. By decoding the dynamic reward probability and the memory of recent outcomes from the dlPFC population response, we show that monkeys create an internal representation of reward dynamics. The decoded variables predicted animal’s subsequent actions better than either the true experimental variables or the raw neural responses. Our results suggest that the relevant task variables and behavioral decisions are dynamically encoded in prefrontal cortex during the time course of foraging.

scholarly journals Disapproval from romantic partners, friends and parents: source of criticism regulates prefrontal cortex activity

2020 ◽  
Author(s):  
Michelle Jin-Yee Neoh ◽  
Atiqah Azhari ◽  
Claudio Mulatti ◽  
Marc H. Bornstein ◽  
Gianluca Esposito
Keyword(s):  
Prefrontal Cortex ◽  
Near Infrared ◽  
Romantic Partners ◽  
Third Party ◽  
Neural Responses ◽  
Functional Near Infrared Spectroscopy ◽  
Relationship Type ◽  
Relationship Types ◽  
Dorsolateral Prefrontal ◽  
Perceived Criticism

AbstractThe prevalence of criticism in everyday social situations, and its empirically demonstrated association with psychopathology, highlight the importance of understanding neural mechanisms underlying the perception and response of individuals to criticism. However, neuroimaging studies to date have been limited largely to maternal criticism. The present study aims to investigate neural responses to criticism originating from three different relationship types: romantic partners, friends, and parents. Perceived criticism ratings for these relationships from 49 participants were collected. Functional near-infrared spectroscopy was used to measure changes in oxygenated haemoglobin levels in the prefrontal cortex when participants read vignettes describing three different scenarios of criticism. Participants were randomly assigned to 3 groups where the given description of the relationship of the protagonist to the source of criticism for each vignette was randomised. A significant interaction between relationship type and perceived criticism ratings for mothers was found in the dorsolateral prefrontal cortex. Compared to low perceived criticism, high perceived criticism individuals showed increased activation reading vignettes describing criticism from romantic partners and parents but decreased activation for those from friends. Findings contribute to understanding neural responses to criticism as observed from a third-party perspective. Future studies can look into differentiating neural responses of personalised experiences of criticism and third-party observations.

scholarly journals A Geometric Characterization of Population Coding in the Prefrontal Cortex and Hippocampus during a Paired-Associate Learning Task

2020 ◽  
Vol 32 (8) ◽  
pp. 1455-1465
Author(s):  
Yue Liu ◽  
Scott L. Brincat ◽  
Earl K. Miller ◽  
Michael E. Hasselmo
Keyword(s):  
Prefrontal Cortex ◽  
Large Scale ◽  
Paired Associate ◽  
Population Level ◽  
Population Coding ◽  
Task Structure ◽  
Population Activity ◽  
Associate Learning ◽  
Task Variables ◽  
Monkey Prefrontal Cortex

Large-scale neuronal recording techniques have enabled discoveries of population-level mechanisms for neural computation. However, it is not clear how these mechanisms form by trial-and-error learning. In this article, we present an initial effort to characterize the population activity in monkey prefrontal cortex (PFC) and hippocampus (HPC) during the learning phase of a paired-associate task. To analyze the population data, we introduce the normalized distance, a dimensionless metric that describes the encoding of cognitive variables from the geometrical relationship among neural trajectories in state space. It is found that PFC exhibits a more sustained encoding of the visual stimuli, whereas HPC only transiently encodes the identity of the associate stimuli. Surprisingly, after learning, the neural activity is not reorganized to reflect the task structure, raising the possibility that learning is accompanied by some “silent” mechanism that does not explicitly change the neural representations. We did find partial evidence on the learning-dependent changes for some of the task variables. This study shows the feasibility of using normalized distance as a metric to characterize and compare population-level encoding of task variables and suggests further directions to explore learning-dependent changes in the neural circuits.

scholarly journals MEG activity of the dorsolateral prefrontal cortex during optic flow stimulations detects mild cognitive impairment due to Alzheimer’s disease

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259677
Author(s):  
Moeko Noguchi-Shinohara ◽  
Masato Koike ◽  
Hirofumi Morise ◽  
Kiwamu Kudo ◽  
Shoko Tsuchimine ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Cognitive Impairment ◽  
Prefrontal Cortex ◽  
Mild Cognitive Impairment ◽  
Optic Flow ◽  
Dorsolateral Prefrontal Cortex ◽  
Brodmann Area ◽  
Maximum Power ◽  
Neural Responses ◽  
Dorsolateral Prefrontal

Dorsal stream, which has a neuronal connection with dorsolateral prefrontal cortex (DLPFC), is known to be responsible for detection of motion including optic flow perception. Using magnetoencephalography (MEG), this study aimed to examine neural responses to optic flow stimuli with looming motion in the DLPFC in patients with mild cognitive impairment due to Alzheimer’s disease (AD-MCI) compared with cognitively unimpaired participants (CU). We analyzed the neural responses by evaluating maximum source-localized power for the AD-MCI group (n = 11) and CU (n = 20), focusing on six regions of interest (ROIs) that form the DLPFC: right and left dorsal Brodmann area 9/46 (A9/46d), Brodmann area 46 (A46) and ventral Brodmann area 9/46 (A9/46v). We found significant differences in the maximum power between the groups in the left A46 and A9/46v. Moreover, in the left A9/46v, the maximum power significantly correlated with the Wechsler Memory Scale-Revised general memory score and delayed recall score. The maximum power in the left A9/46v also revealed high performance in AD-MCI versus CU classification with the area under the ROC curve of 0.90. This study demonstrated that MEG during the optic flow task can be useful in discriminating AD-MCI from CU.

scholarly journals Maturation of prefrontal input to dorsal raphe increases behavioral persistence in mice

2022 ◽  
Author(s):  
Nicolas Gutierrez-Castellanos ◽  
Dario Sarra ◽  
Beatriz Godinho ◽  
Zachary Mainen
Keyword(s):  
Prefrontal Cortex ◽  
Time Course ◽  
Behavioral Control ◽  
Developmental Time ◽  
Dorsal Raphe ◽  
Fundamental Aspect ◽  
Behavioral Persistence ◽  
Genetic Targeting ◽  
Foraging Task ◽  
Dorsal Raphé

The ability to persist towards a desired objective is a fundamental aspect of behavioral control whose impairment is implicated in several behavioral disorders. One of the prominent features of behavioral persistence is that its maturation occurs relatively late in development. This is presumed to echo the developmental time course of a corresponding circuit within late-maturing parts of the brain, such as the prefrontal cortex, but the specific identity of the responsible circuits is unknown. Here, we describe the maturation of the projection from layer 5 neurons of the prefrontal cortex to the dorsal raphe nucleus in mice. We show using pathway-specific optogenetic stimulation that this connection undergoes a dramatic increase in synaptic potency between postnatal weeks 3 and 8, corresponding to the transition from juvenile to adult. We then show that this period corresponds to an increase in the behavioral persistence that mice exhibit in a foraging task. Finally, we use genetic targeting to selectively ablate this pathway in adulthood and show that mice revert to a behavioral phenotype similar to juveniles. These results suggest that the prefrontal to dorsal raphe pathway is a critical anatomical and functional substrate of the development and manifestation of behavioral control.

scholarly journals Monkey prefrontal neurons during Sternberg task performance: full contents of working memory or most recent item?

2017 ◽  
Vol 117 (6) ◽  
pp. 2269-2281 ◽  
Author(s):  
R. O. Konecky ◽  
M. A. Smith ◽  
C. R. Olson
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Firing Rate ◽  
Dorsolateral Prefrontal Cortex ◽  
Memory Task ◽  
Delay Period ◽  
Population Activity ◽  
Storage Mechanism ◽  
Dorsolateral Prefrontal ◽  
Recent Item

To explore the brain mechanisms underlying multi-item working memory, we monitored the activity of neurons in the dorsolateral prefrontal cortex while macaque monkeys performed spatial and chromatic versions of a Sternberg working-memory task. Each trial required holding three sequentially presented samples in working memory so as to identify a subsequent probe matching one of them. The monkeys were able to recall all three samples at levels well above chance, exhibiting modest load and recency effects. Prefrontal neurons signaled the identity of each sample during the delay period immediately following its presentation. However, as each new sample was presented, the representation of antecedent samples became weak and shifted to an anomalous code. A linear classifier operating on the basis of population activity during the final delay period was able to perform at approximately the level of the monkeys on trials requiring recall of the third sample but showed a falloff in performance on trials requiring recall of the first or second sample much steeper than observed in the monkeys. We conclude that delay-period activity in the prefrontal cortex robustly represented only the most recent item. The monkeys apparently based performance of this classic working-memory task on some storage mechanism in addition to the prefrontal delay-period firing rate. Possibilities include delay-period activity in areas outside the prefrontal cortex and changes within the prefrontal cortex not manifest at the level of the firing rate. NEW & NOTEWORTHY It has long been thought that items held in working memory are encoded by delay-period activity in the dorsolateral prefrontal cortex. Here we describe evidence contrary to that view. In monkeys performing a serial multi-item working memory task, dorsolateral prefrontal neurons encode almost exclusively the identity of the sample presented most recently. Information about earlier samples must be encoded outside the prefrontal cortex or represented within the prefrontal cortex in a cryptic code.

P231 The time course of functional recruitment of dorsolateral prefrontal cortex during interference control

2017 ◽  
Vol 128 (3) ◽  
pp. e128
Author(s):  
D. Redolar-Ripoll ◽  
R. Viejo-Sobera ◽  
M. Palaus ◽  
A. Valero-Cabre ◽  
E.M. Marron
Keyword(s):  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Time Course ◽  
Interference Control ◽  
Dorsolateral Prefrontal

scholarly journals A geometric characterization of population coding in the prefrontal cortex and hippocampus during a paired-associate learning task

2019 ◽  
Author(s):  
Yue Liu ◽  
Scott L Brincat ◽  
Earl K Miller ◽  
Michael E Hasselmo
Keyword(s):  
Prefrontal Cortex ◽  
Large Scale ◽  
Paired Associate ◽  
Population Data ◽  
Population Level ◽  
Population Coding ◽  
Population Activity ◽  
Associate Learning ◽  
Task Variables ◽  
Monkey Prefrontal Cortex

Large-scale neuronal recording techniques have enabled discoveries of population-level mechanisms for neural computation. However it is not clear how these mechanisms form by trial and error learning. In this paper we present an initial effort to characterize the population activity in monkey prefrontal cortex (PFC) and hippocampus (HPC) during the learning phase of a paired-associate task. To analyze the population data, we introduce the normalized distance, a dimensionless metric that describes the encoding of cognitive variables from the geometrical relationship among neural trajectories in state space. It is found that PFC exhibits a more sustained encoding of task-relevant variables whereas HPC only transiently encodes the identity of the stimuli. We also found partial evidence on the learning-dependent changes for some of the task variables. This study shows the feasibility of using normalized distance as a metric to characterize and compare population level encoding of task variables, and suggests further directions to explore the learning-dependent changes in the population activity.

scholarly journals A dynamic code for economic object valuation in prefrontal cortex neurons

2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Ken-Ichiro Tsutsui ◽  
Fabian Grabenhorst ◽  
Shunsuke Kobayashi ◽  
Wolfram Schultz
Keyword(s):  
Prefrontal Cortex ◽  
Matching Law ◽  
Recent Experience ◽  
Physiological Basis ◽  
Economic Decisions ◽  
Decision Variables ◽  
Dorsolateral Prefrontal ◽  
Subsequent Conversion ◽  
Object Valuation ◽  
Foraging Task

Abstract Neuronal reward valuations provide the physiological basis for economic behaviour. Yet, how such valuations are converted to economic decisions remains unclear. Here we show that the dorsolateral prefrontal cortex (DLPFC) implements a flexible value code based on object-specific valuations by single neurons. As monkeys perform a reward-based foraging task, individual DLPFC neurons signal the value of specific choice objects derived from recent experience. These neuronal object values satisfy principles of competitive choice mechanisms, track performance fluctuations and follow predictions of a classical behavioural model (Herrnstein’s matching law). Individual neurons dynamically encode both, the updating of object values from recently experienced rewards, and their subsequent conversion to object choices during decision-making. Decoding from unselected populations enables a read-out of motivational and decision variables not emphasized by individual neurons. These findings suggest a dynamic single-neuron and population value code in DLPFC that advances from reward experiences to economic object values and future choices.

scholarly journals Distinct neural dynamics underlie the encoding of visual speed in stationary and running mice

2021 ◽  
Author(s):  
Edward A B Horrocks ◽  
Aman B Saleem
Keyword(s):  
Single Neuron ◽  
Dynamic Range ◽  
Temporal Dynamics ◽  
Population Coding ◽  
Neural Responses ◽  
Population Activity ◽  
Visual Inputs ◽  
Structure Of Population ◽  
Time Courses ◽  
Visual Speed

Sensory experiences are often driven by an animal's self-motion and locomotion is known to modulate neural responses in the mouse visual system. This modulation is hypothesised to improve the processing of behaviourally relevant visual inputs, which may change rapidly during locomotion. However, little is known about how locomotion modulates the temporal dynamics (time courses) of visually-evoked neural responses. Here, we analysed the temporal dynamics of single neuron and population responses to dot field stimuli moving at a range of visual speeds using the Visual Coding dataset from the Allen Institute for Brain Science (Siegle et al, 2021). Single neuron responses had diverse temporal dynamics that varied between stationary and running sessions. Increased dynamic range and more reliable responses in running sessions enabled faster, stronger and more persistent encoding of visual speed. Population activity reflected the temporal dynamics of single neuron responses, including their modulation by locomotor state - neural trajectories of population activity made more direct transitions between baseline and stimulus steady states in running sessions. The structure of population coding also changed with locomotor state - population activity prioritised the encoding of visual speed in running, but not stationary sessions. Our results reveal a profound influence of locomotion on the temporal dynamics of neural responses. We demonstrate that during locomotion, mouse visual areas prioritise the encoding of potentially fast-changing, behaviourally relevant visual features.

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