Neural activity in macaque prefrontal cortex in flexible switching of search strategies

Neurological patients with focal lesions in the dorsolateral prefrontal cortex and age-matched control subjects were tested on an auditory version of the delayed-match-to-sample task employing environmental sounds. Subjects had to indicate whether a cue (S1) and a subsequent target sound (S2) were identical. On some trials, S1 and S2 were separated by a silent period of 5 sec. On other trials, the 5-sec delay between S1 and S2 was filled with irrelevant tone pips that served as distractors. Behaviorally, frontal patients were impaired by the presence of distractors. Electrophysiologically, patients generated enhanced primary auditory cortex-evoked responses to the tone pips, supporting a failure in inhibitory control of sensory processing after prefrontal damage. Intrahemispheric reductions of neural activity generated in the auditory association cortex and additional intrahemispheric reductions of attention-related frontal activity were also observed in the prefrontal patients. Together, these findings suggest that the dorsolateral prefrontal cortex is crucial for gating distracting information as well as maintaining distributed intrahemispheric neural activity during auditory working memory.

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Rapid Association Learning in the Primate Prefrontal Cortex in the Absence of Behavioral Reversals

Journal of Cognitive Neuroscience ◽

10.1162/jocn.2010.21555 ◽

2011 ◽

Vol 23 (7) ◽

pp. 1823-1828 ◽

Cited By ~ 11

Author(s):

Jason A. Cromer ◽

Michelle Machon ◽

Earl K. Miller

Keyword(s):

Prefrontal Cortex ◽

Neural Activity ◽

Association Learning ◽

Conditional Association ◽

And Behavior ◽

The Relationship ◽

Behavioral Improvement ◽

Previous Learning

The PFC plays a central role in our ability to learn arbitrary rules, such as “green means go.” Previous experiments from our laboratory have used conditional association learning to show that slow, gradual changes in PFC neural activity mirror monkeys' slow acquisition of associations. These previous experiments required monkeys to repeatedly reverse the cue–saccade associations, an ability known to be PFC-dependent. We aimed to test whether the relationship between PFC neural activity and behavior was due to the reversal requirement, so monkeys were trained to learn several new conditional cue–saccade associations without reversing them. Learning-related changes in PFC activity now appeared earlier and more suddenly in correspondence with similar changes in behavioral improvement. This suggests that learning of conditional associations is linked to PFC activity regardless of whether reversals are required. However, when previous learning does not need to be suppressed, PFC acquires associations more rapidly.

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A Comparison of Abstract Rules in the Prefrontal Cortex, Premotor Cortex, Inferior Temporal Cortex, and Striatum

Journal of Cognitive Neuroscience ◽

10.1162/jocn.2006.18.6.974 ◽

2006 ◽

Vol 18 (6) ◽

pp. 974-989 ◽

Cited By ~ 133

Author(s):

Rahmat Muhammad ◽

Jonathan D. Wallis ◽

Earl K. Miller

Keyword(s):

Prefrontal Cortex ◽

Neural Activity ◽

Premotor Cortex ◽

Temporal Cortex ◽

Dorsal Striatum ◽

Behavioral Responses ◽

Inferior Temporal Cortex ◽

Perceptual Information ◽

Lateral Prefrontal Cortex

The ability to use abstract rules or principles allows behavior to generalize from specific circumstances. We have previously shown that such rules are encoded in the lateral prefrontal cortex (PFC) and premotor cortex (PMC). Here, we extend these investigations to two other areas directly connected with the PFC and the PMC, the inferior temporal cortex (ITC) and the dorsal striatum (STR). Monkeys were trained to use two abstract rules: “same” or “different”. They had to either hold or release a lever, depending on whether two successively presented pictures were the same or different, and depending on which rule was in effect. The rules and the behavioral responses were reflected most strongly and, on average, tended to be earlier in the PMC followed by the PFC and then the STR; few neurons in the ITC reflected the rules or the actions. By contrast, perceptual information (the identity of the pictures used as sample and test stimuli) was encoded more strongly and earlier in the ITC, followed by the PFC; they had weak, if any, effects on neural activity in the PMC and STR. These findings are discussed in the context of the anatomy and posited functions of these areas.

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Enhanced synchronization between prelimbic and infralimbic cortices during fear extinction learning

Molecular Brain ◽

10.1186/s13041-021-00884-6 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Mayumi Watanabe ◽

Akira Uematsu ◽

Joshua P. Johansen

Keyword(s):

Prefrontal Cortex ◽

Neural Activity ◽

Fear Extinction ◽

Synaptic Connectivity ◽

Prelimbic Cortex ◽

Field Potentials ◽

Infralimbic Cortex ◽

Extinction Learning ◽

Gamma Frequency ◽

Learned Fear

AbstractThe ability to extinguish aversive memories when they are no longer associated with danger is critical for balancing survival with competing adaptive demands. Previous studies demonstrated that the infralimbic cortex (IL) is essential for extinction of learned fear, while neural activity in the prelimbic cortex (PL) facilitates fear responding and is negatively correlated with the strength of extinction memories. Though these adjacent regions in the prefrontal cortex maintain mutual synaptic connectivity, it has been unclear whether PL and IL interact functionally with each other during fear extinction learning. Here we addressed this question by recording local field potentials (LFPs) simultaneously from PL and IL of awake behaving rats during extinction of auditory fear memories. We found that LFP power in the fast gamma frequency (100–200 Hz) in both PL and IL regions increased during extinction learning. In addition, coherency analysis showed that synchronization between PL and IL in the fast gamma frequency was enhanced over the course of extinction. These findings support the hypothesis that interregional interactions between PL and IL increase as animals extinguish aversive memories.

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The eyes reflect an internal cognitive state hidden in the population activity of cortical neurons

10.1101/2020.06.29.178251 ◽

2020 ◽

Cited By ~ 1

Author(s):

Richard Johnston ◽

Adam C. Snyder ◽

Sanjeev B. Khanna ◽

Deepa Issar ◽

Matthew A. Smith

Keyword(s):

Prefrontal Cortex ◽

Visual Cortex ◽

Eye Movements ◽

Neural Activity ◽

Detection Task ◽

Change Detection Task ◽

Population Activity ◽

Slow Drift ◽

Global Brain ◽

The Brain

SummaryDecades of research have shown that global brain states such as arousal can be indexed by measuring the properties of the eyes. Neural signals from individual neurons, populations of neurons, and field potentials measured throughout much of the brain have been associated with the size of the pupil, small fixational eye movements, and vigor in saccadic eye movements. However, precisely because the eyes have been associated with modulation of neural activity across the brain, and many different kinds of measurements of the eyes have been made across studies, it has been difficult to clearly isolate how internal states affect the behavior of the eyes, and vice versa. Recent work in our laboratory identified a latent dimension of neural activity in macaque visual cortex on the timescale of minutes to tens of minutes. This ‘slow drift’ was associated with perceptual performance on an orientation-change detection task, as well as neural activity in visual and prefrontal cortex (PFC), suggesting it might reflect a shift in a global brain state. This motivated us to ask if the neural signature of this internal state is correlated with the action of the eyes in different behavioral tasks. We recorded from visual cortex (V4) while monkeys performed a change detection task, and the prefrontal cortex, while they performed a memory-guided saccade task. On both tasks, slow drift was associated with a pattern that is indicative of changes in arousal level over time. When pupil size was large, and the subjects were in a heighted state of arousal, microsaccade rate and reaction time decreased while saccade velocity increased. These results show that the action of the eyes is associated with a dominant mode of neural activity that is pervasive and task-independent, and can be accessed in the population activity of neurons across the cortex.

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Slow drift of neural activity as a signature of impulsivity in macaque visual and prefrontal cortex

10.1101/2020.01.10.902403 ◽

2020 ◽

Cited By ~ 2

Author(s):

Benjamin R. Cowley ◽

Adam C. Snyder ◽

Katerina Acar ◽

Ryan C. Williamson ◽

Byron M. Yu ◽

...

Keyword(s):

Decision Making ◽

Prefrontal Cortex ◽

Neural Activity ◽

Internal State ◽

Sensory Stimulus ◽

Perceptual Decision Making ◽

Population Activity ◽

Perceptual Decision ◽

Slow Drift ◽

Sensory Evidence

AbstractAn animal’s decision depends not only on incoming sensory evidence but also on its fluctuating internal state. This internal state is a product of cognitive factors, such as fatigue, motivation, and arousal, but it is unclear how these factors influence the neural processes that encode the sensory stimulus and form a decision. We discovered that, over the timescale of tens of minutes during a perceptual decision-making task, animals slowly shifted their likelihood of reporting stimulus changes. They did this unprompted by task conditions. We recorded neural population activity from visual area V4 as well as prefrontal cortex, and found that the activity of both areas slowly drifted together with the behavioral fluctuations. We reasoned that such slow fluctuations in behavior could either be due to slow changes in how the sensory stimulus is processed or due to a process that acts independently of sensory processing. By analyzing the recorded activity in conjunction with models of perceptual decision-making, we found evidence for the slow drift in neural activity acting as an impulsivity signal, overriding sensory evidence to dictate the final decision. Overall, this work uncovers an internal state embedded in the population activity across multiple brain areas, hidden from typical trial-averaged analyses and revealed only when considering the passage of time within each experimental session. Knowledge of this cognitive factor was critical in elucidating how sensory signals and the internal state together contribute to the decision-making process.

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Reforming Sectarian Beliefs in Iraq: Winning the Peace

Communication Society and Media ◽

10.22158/csm.v4n1p8 ◽

2021 ◽

Vol 4 (1) ◽

pp. p8

Author(s):

Michael Oler ◽

Anthony Johnson ◽

Anna McCulloh ◽

Munqith Dagher ◽

Anita Day ◽

...

Keyword(s):

Prefrontal Cortex ◽

Neural Activity ◽

Public Perception ◽

Near Infrared ◽

Brain Regions ◽

Frontal Pole ◽

Functional Near Infrared Spectroscopy ◽

Imaging Device ◽

Neural Imaging ◽

The Right

Sectarian violence continues in Iraq affecting regional and world security. Neuroscience techniques are used to assess the mentalizing process and counter-arguing in response to videos designed to prevent extremist radicalization. Measurement of neural activity in brain Regions of Interest (ROI) assists identification of messages which can promote favorable behavior. Activation of the Medial Prefrontal Cortex (MPFC) is associated with message adoption and behavior change. Public Service Announcements (PSAs) have not been effective in reducing violence in Iraq. This study demonstrates that the four PSAs investigated in this study do not activate the MPFC. The RLPFC is a brain ROI associated with counter-arguing and message resistance. This study demonstrates that reduction in activity in the Right Lateral Prefrontal Cortex (RLPFC) is associated with decreased sectarianism. Engagement was measured and is associated with activity in the frontal pole regions.We introduce Functional Near-infrared Spectroscopy (fNIRS) to measure the neural activity of highly sectarian Iraqis in response to these anti-sectarian messages. Neural activity was measured while viewing three PSAs and a fourth unpublished video. All four videos are intended to reduce sectarianism. A novel sectarianism scale is introduced to measure sectarian beliefs before and after the messages. This sectarian scale has high internal consistency as measured by Cronbach’s alpha. Measured activation of brain ROIs are correlated with changes in the sectarian scale. Twelve Sunni and twelve Shi’a Iraqis participated in the study. Subjects were shown the four videos in randomized order, while equipped with a fNIRS neural imaging device. All four videos produced significant engagement. None of the videos reduced sectarianism nor caused brain activation of adoption. This is consistent with the widely held Iraqi public perception that the PSAs are ineffective. Only one video, which was un-published, caused reduced sectarian beliefs. This un-published fourth video was associated with decreased counter-arguing. Counter-arguing is associated with message resistance.

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Large- and multi-scale networks in the rodent brain during novelty exploration

10.1101/2020.12.08.416248 ◽

2020 ◽

Author(s):

Michael X Cohen ◽

Bernhard Englitz ◽

Arthur S C França

Keyword(s):

Prefrontal Cortex ◽

Parietal Cortex ◽

Local Field ◽

Neural Activity ◽

Large Scale ◽

Field Potential ◽

Brain Regions ◽

Data Availability ◽

Data Matrix ◽

Temporal Scales

AbstractNeural activity is coordinated across multiple spatial and temporal scales, and these patterns of coordination are implicated in both healthy and impaired cognitive operations. However, empirical cross-scale investigations are relatively infrequent, due to limited data availability and to the difficulty of analyzing rich multivariate datasets. Here we applied frequency-resolved multivariate source-separation analyses to characterize a large-scale dataset comprising spiking and local field potential activity recorded simultaneously in three brain regions (prefrontal cortex, parietal cortex, hippocampus) in freely-moving mice. We identified a constellation of multidimensional, inter-regional networks across a range of frequencies (2-200 Hz). These networks were reproducible within animals across different recording sessions, but varied across different animals, suggesting individual variability in network architecture. The theta band (~4-10 Hz) networks had several prominent features, including roughly equal contribution from all regions and strong inter-network synchronization. Overall, these findings demonstrate a multidimensional landscape of large-scale functional activations of cortical networks operating across multiple spatial, spectral, and temporal scales during open-field exploration.Significance statementNeural activity is synchronized over space, time, and frequency. To characterize the dynamics of large-scale networks spanning multiple brain regions, we recorded data from the prefrontal cortex, parietal cortex, and hippocampus in awake behaving mice, and pooled data from spiking activity and local field potentials into one data matrix. Frequency-specific multivariate decomposition methods revealed a cornucopia of neural networks defined by coherent spatiotemporal patterns over time. These findings reveal a rich, dynamic, and multivariate landscape of large-scale neural activity patterns during foraging behavior.

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Active maintenance of eligibility trace in rodent prefrontal cortex

Scientific Reports ◽

10.1038/s41598-020-75820-0 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Dong-Hyun Lim ◽

Young Ju Yoon ◽

Eunsil Her ◽

Suehee Huh ◽

Min Whan Jung

Keyword(s):

Prefrontal Cortex ◽

Neuronal Activity ◽

Neural Activity ◽

Credit Assignment ◽

Neural Signals ◽

Active Maintenance ◽

Time Period ◽

Eligibility Trace ◽

Action Value ◽

Foraging Task

Abstract Even though persistent neural activity has been proposed as a mechanism for maintaining eligibility trace, direct empirical evidence for active maintenance of eligibility trace has been lacking. We recorded neuronal activity in the medial prefrontal cortex (mPFC) in rats performing a dynamic foraging task in which a choice must be remembered until its outcome on the timescale of seconds for correct credit assignment. We found that mPFC neurons maintain significant choice signals during the time period between action selection and choice outcome. We also found that neural signals for choice, outcome, and action value converge in the mPFC when choice outcome was revealed. Our results indicate that the mPFC maintains choice signals necessary for temporal credit assignment in the form of persistent neural activity in our task. They also suggest that the mPFC might update action value by combining actively maintained eligibility trace with action value and outcome signals.

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