scholarly journals The role of Gamma oscillations in binding ambiguous visual input into coherent percepts

2010 ◽  
Vol 9 (8) ◽  
pp. 923-923 ◽  
Author(s):  
H.-P. Frey ◽  
M. Naber ◽  
W. Einhauser ◽  
J. Foxe
Keyword(s):  
Gamma Oscillations ◽  
Visual Input

Hippocampal-prefrontal theta coupling develops as mice become proficient in associative odorant discrimination learning

2021 ◽  
Author(s):  
Daniel Ramirez-Gordillo ◽  
Andrew A. Parra ◽  
K. Ulrich Bayer ◽  
Diego Restrepo
Keyword(s):  
Learning And Memory ◽  
Discrimination Learning ◽  
Gamma Oscillations ◽  
Oscillatory Activity ◽  
Dependent Protein Kinase ◽  
Dependent Protein ◽  
Theta Phase ◽  
Phase Amplitude ◽  
The Brain

Learning and memory requires coordinated activity between different regions of the brain. Here we studied the interaction between medial prefrontal cortex (mPFC) and hippocampal dorsal CA1 during associative odorant discrimination learning in the mouse. We found that as the animal learns to discriminate odorants in a go-no go task the coupling of high frequency neural oscillations to the phase of theta oscillations (phase-amplitude coupling or PAC) changes in a manner that results in divergence between rewarded and unrewarded odorant-elicited changes in the theta-phase referenced power (tPRP) for beta and gamma oscillations. In addition, in the proficient animal there was a decrease in the coordinated oscillatory activity between CA1 and mPFC in the presence of the unrewarded odorant. Furthermore, the changes in PAC resulted in a marked increase in the accuracy for decoding odorant identity from tPRP when the animal became proficient. Finally, we studied the role of Ca2+/calmodulin-dependent protein kinase II α (CaMKIIα), a protein involved in learning and memory, in oscillatory neural processing in this task. We find that the accuracy for decoding the odorant identity from tPRP decreases in CaMKIIα knockout mice and that this accuracy correlates with behavioral performance. These results implicate a role for PAC and CaMKIIα in olfactory go-no go associative learning in the hippocampal-prefrontal circuit.

The role of cinematic techniques in understanding character affect

2017 ◽  
Vol 7 (2) ◽  
pp. 177-202
Author(s):  
James A. Clinton ◽  
Stephen W. Briner ◽  
Andrew M. Sherrill ◽  
Thomas Ackerman ◽  
Joseph P. Magliano
Keyword(s):  
Facial Expressions ◽  
Visual Input ◽  
Point Of View ◽  
Affective States ◽  
Basic Emotions

Abstract Filmmakers must rely on cinematic devices of perspective (close-ups and point-of-view shot sequencing) to emphasize facial expressions associated with affective states. This study explored the extent to which differences in the use of these devices across two films that have the same content lead to differences in the understanding of the affective states of characters. Participants viewed one of two versions of the films and made affective judgments about how characters felt about one another with respect to saddness and anger. The extent to which the auditory and visual contexts were present when making the judgments was varied across four experiments. The results of the study showed judgments about sadness differed across the two films, but only when the entire context (sound and visual input) were present. The results are discussed in the context of the role of facial expressions and context in inferring basic emotions.

The synergistic effect of reduced visual input on ketamine action: The possible role of the pineal gland

1973 ◽  
Vol 12 (5) ◽  
pp. 407-416 ◽  
Author(s):  
W.D. Winters ◽  
M. Alcaraz ◽  
M.Y. Cervantes ◽  
C. Guzman-Flores
Keyword(s):  
Synergistic Effect ◽  
Pineal Gland ◽  
Visual Input

The Role of Brain Oscillations in the Temporal Limits of Attention

2014 ◽  
Author(s):  
Kimron Shapiro ◽  
Simon Hanslmayr
Keyword(s):  
Frequency Band ◽  
Visual Space ◽  
Visual Input ◽  
Brain Oscillations ◽  
Approaches To Studying ◽  
Alpha Frequency ◽  
Alpha Frequency Band ◽  
Long Time ◽  
The Brain

Attention is the ubiquitous construct referring to the ability of the brain to focus resources on a subset of perceptual input which it is trying to process for a response. Attention has for a long time been studied with reference to its distribution across space where, for example, visual input from an attentionally monitored location is given preference over non-monitored (i.e. attended) locations. More recently, attention has been studied for its ability to select targets from among rapidly, sequentially presented non-targets at a fixed location, e.g. in visual space. The present chapter explores this latter function of attention for its relevance to behaviour. In so doing, it highlights what is becoming one of the most popular approaches to studying communication across the brain—oscillations—at various frequency ranges. In particular the authors discuss the alpha frequency band (8–12 Hz), where recent evidence points to an important role in the switching between processing external vs. internal events.

scholarly journals Top-down Control of Inhibition Reshapes Neural Dynamics Giving Rise to a Diversity of Computations

2020 ◽  
Author(s):  
Zhen Chen ◽  
Krishnan Padmanabhan
Keyword(s):  
Network Dynamics ◽  
Gamma Oscillations ◽  
Sensory Systems ◽  
Pattern Separation ◽  
Inhibitory Neurons ◽  
Top Down ◽  
Brain Areas ◽  
Excitatory Neurons ◽  
Local Circuits

AbstractGrowing evidence shows that top-down projections from excitatory neurons in higher brain areas selectively synapse onto local inhibitory interneurons in sensory systems. While this connectivity is conserved across sensory modalities, the role of this feedback in shaping the dynamics of local circuits, and the resultant computational benefits it provides remains poorly understood. Using rate models of neuronal firing in a network consisting of excitatory, inhibitory and top-down populations, we found that changes in the weight of feedback to inhibitory neurons generated diverse network dynamics and complex transitions between these dynamics. Additionally, modulation of the weight of top-down feedback supported a number of computations, including both pattern separation and oscillatory synchrony. A bifurcation analysis of the network identified a new mechanism by which gamma oscillations could be generated in a model of neural circuits, which we termed Top-down control of Inhibitory Neuron Gamma (TING). We identified the unique roles that top-down feedback of inhibition plays in shaping network dynamics and computation, and the ways in which these dynamics can be deployed to process sensory inputs.Significance StatementThe functional role of feedback projections, connecting excitatory neurons in higher brain areas to inhibitory neurons in primary sensory regions, remains a fundamental open question in neuroscience. Growing evidence suggests that this architecture is recapitulated across a diverse array of sensory systems, ranging from vision to olfaction. Using a rate model of top-down feedback onto inhibition, we found that changes in the weight of feedback support both pattern separation and oscillatory synchrony, including a mechanism by which top-down inputs could entrain gamma oscillations within local networks. These dual functions were accomplished via a codimension-2 bifurcation in the dynamical system. Our results highlight a key role for this top-down feedback, gating inhibition to facilitate often diametrically different local computations.

scholarly journals Disrupted-in-Schizophrenia-1 is required for proper pyramidal cell-interneuron communication and network dynamics in the prefrontal cortex

2021 ◽  
Author(s):  
Jonas-Frederic Sauer ◽  
Marlene Bartos
Keyword(s):  
Pyramidal Cell ◽  
Gamma Oscillations ◽  
Mutant Mice ◽  
Potential Mechanism ◽  
Excitatory Effect ◽  
Fast Spiking ◽  
Single Unit Recordings ◽  
Circuit Function

AbstractWe interrogated prefrontal circuit function in mice lacking Disrupted-in-schizophrenia-1 (Disc1-mutant mice), a risk factor for psychiatric disorders. Single-unit recordings in awake mice revealed reduced average firing rates of fast-spiking interneurons (INTs), including optogenetically identified parvalbumin-positive cells, and a lower proportion of INTs phase-coupled to ongoing gamma oscillations. Moreover, we observed decreased spike transmission efficacy at local pyramidal cell (PYR)-INT connections in vivo, suggesting a reduced excitatory effect of local glutamatergic inputs as a potential mechanism of lower INT rates. On the network level, impaired INT function resulted in altered activation of PYR assemblies: While assembly activations were observed equally often, the expression strength of individual assembly patterns was significantly higher in Disc1-mutant mice. Our data thus reveal a role of Disc1 in shaping the properties of prefrontal assembly patterns by setting prefrontal INT responsiveness to glutamatergic drive.

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