scholarly journals Posterior Alpha and Gamma Oscillations Index Divergent and Superadditive Effects of Cognitive Interference

2019 ◽  
Vol 30 (3) ◽  
pp. 1931-1945 ◽  
Author(s):  
Alex I Wiesman ◽  
Tony W Wilson
Keyword(s):  
Spatial Dynamics ◽  
Irrelevant Stimulus ◽  
Spatial Location ◽  
Cognitive Conflict ◽  
Gamma Oscillations ◽  
Relevant Stimulus ◽  
Cognitive Interference ◽  
Motor Mapping ◽  
Stimulus Response ◽  
Gamma Frequency

Abstract Conflicts at various stages of cognition can cause interference effects on behavior. Two well-studied forms of cognitive interference are stimulus–stimulus (e.g., Flanker), where the conflict arises from incongruence between the task-relevant stimulus and simultaneously presented irrelevant stimulus information, and stimulus-response (e.g., Simon), where interference is the result of an incompatibility between the spatial location of the task-relevant stimulus and a prepotent motor mapping of the expected response. Despite substantial interest in the neural and behavioral underpinnings of cognitive interference, it remains uncertain how differing sources of cognitive conflict might interact, and the spectrally specific neural dynamics that index this phenomenon are poorly understood. Herein, we used an adapted version of the multisource interference task and magnetoencephalography to investigate the spectral, temporal, and spatial dynamics of conflict processing in healthy adults (N = 23). We found a double-dissociation such that, in isolation, stimulus–stimulus interference was indexed by alpha (8–14 Hz), but not gamma-frequency (64–76 Hz) oscillations in the lateral occipital regions, while stimulus–response interference was indexed by gamma oscillations in nearby cortices, but not by alpha oscillations. Surprisingly, we also observed a superadditive effect of simultaneously presented interference types (multisource) on task performance and gamma oscillations in superior parietal cortex.

scholarly journals Properties of precise firing synchrony between synaptically coupled cortical interneurons depend on their mode of coupling

2015 ◽  
Vol 114 (1) ◽  
pp. 624-637 ◽  
Author(s):  
Hang Hu ◽  
Ariel Agmon
Keyword(s):  
Firing Rate ◽  
Electrical Coupling ◽  
Gamma Oscillations ◽  
Inhibitory Synapses ◽  
Data Set ◽  
Temporal Precision ◽  
Gamma Frequency ◽  
Rate Dependent ◽  
Cortical Interneurons

Precise spike synchrony has been widely reported in the central nervous system, but its functional role in encoding, processing, and transmitting information is yet unresolved. Of particular interest is firing synchrony between inhibitory cortical interneurons, thought to drive various cortical rhythms such as gamma oscillations, the hallmark of cognitive states. Precise synchrony can arise between two interneurons connected electrically, through gap junctions, chemically, through fast inhibitory synapses, or dually, through both types of connections, but the properties of synchrony generated by these different modes of connectivity have never been compared in the same data set. In the present study we recorded in vitro from 152 homotypic pairs of two major subtypes of mouse neocortical interneurons: parvalbumin-containing, fast-spiking (FS) interneurons and somatostatin-containing (SOM) interneurons. We tested firing synchrony when the two neurons were driven to fire by long, depolarizing current steps and used a novel synchrony index to quantify the strength of synchrony, its temporal precision, and its dependence on firing rate. We found that SOM-SOM synchrony, driven solely by electrical coupling, was less precise than FS-FS synchrony, driven by inhibitory or dual coupling. Unlike SOM-SOM synchrony, FS-FS synchrony was strongly firing rate dependent and was not evident at the prototypical 40-Hz gamma frequency. Computer simulations reproduced these differences in synchrony without assuming any differences in intrinsic properties, suggesting that the mode of coupling is more important than the interneuron subtype. Our results provide novel insights into the mechanisms and properties of interneuron synchrony and point out important caveats in current models of cortical oscillations.

Representing Response Position Relative to Display Location: Influence on Orthogonal Stimulus–Response Compatibility

2005 ◽  
Vol 58 (5) ◽  
pp. 839-864 ◽  
Author(s):  
Yang Seok Cho ◽  
Robert W. Proctor
Keyword(s):  
Irrelevant Stimulus ◽  
Stimulus Onset ◽  
The Body ◽  
Response Compatibility ◽  
Response Position ◽  
Stimulus Response ◽  
Stimulus Set ◽  
Response Sets ◽  
Stimulus Response Compatibility ◽  
Display Location

Two types of stimulus–response compatibility (SRC) effect occur with orthogonal stimulus and response sets, an overall up–right/down–left advantage and mapping preferences that vary with response position. Researchers agree that the former type is due to asymmetric coding of the stimulus and response alternatives, but disagree as to whether the latter type requires a different explanation in terms of the properties of the motor system. This issue is examined in three experiments. The location of the stimulus set influenced orthogonal SRC when it varied along the same dimension as the responses (Experiments 1 and 2), with the pattern predicted by the hypothesis that the stimulus set provides a referent relative to which response position is coded. The effect of stimulus-set location on orthogonal SRC was independent of the stimulus onset asynchrony (SOA) for a marker that indicated stimulus-set side and the imperative stimulus. In contrast, a spatial correspondence effect for the irrelevant stimulus-set location and response was a decreasing function of SOA. Experiment 3 showed that the orthogonal SRC effect was determined by response position relative to the stimulus-set location and not the body midline. The results support the view that both types of orthogonal SRC effects are due to asymmetric coding of the stimuli and responses.

The Spatial Dynamics of the May 1968 French Demonstrations

2008 ◽  
Vol 13 (1) ◽  
pp. 83-97 ◽  
Author(s):  
Lilian Mathieu
Keyword(s):  
Social Movement ◽  
Spatial Dynamics ◽  
Spatial Location ◽  
Radical Right ◽  
Recent Interest ◽  
May 1968 ◽  
May 68 ◽  
Repertoire Of Contention

The article studies the May 68 demonstrations in four cities: Paris, Lyon, Saint-Etienne and Roanne, and relies mainly on the archives of the French police. Its main aim is to show that what happened in French streets in May and June 1968 largely depended on the dynamics of the interactions between different contending groups—students, workers, police, radical-right groups, and government supporters—and that an important part of these interactions was determined by the significance these groups gave to the various settings where the events took place, and by the ownership they claimed to have over them. The article relies on the recent interest of social movement scholars for the spatial location of contention, but also on Goffman's theory of the territory of self, to analyze together the symbolic and the strategic dimensions of the May 68 repertoire of contention.

Modulation of preparatory neuronal activity in dorsal premotor cortex due to stimulus-response compatibility

1994 ◽  
Vol 71 (3) ◽  
pp. 1281-1284 ◽  
Author(s):  
D. J. Crammond ◽  
J. F. Kalaska
Keyword(s):  
Neuronal Activity ◽  
Premotor Cortex ◽  
Spatial Location ◽  
Dorsal Premotor Cortex ◽  
Reaching Task ◽  
Stimulus Response ◽  
Sustained Activity ◽  
Spatial Attributes ◽  
Direction Of Movement ◽  
Selection Of

1. Neuronal activity was recorded in the dorsal premotor cortex (PMd) of two monkeys performing a multidirectional, instructed-delay (ID) reaching task in which visuospatial cues signaled the direction of movement either congruent with the instruction cue ("direct-delay" trials, DD) or redirected 180 degrees opposite to the cue ("redirected-delay" trials, RD). Therefore, this task had two degrees of stimulus-response (S-R) compatibility because in one-half of the trials the spatial attributes of the visual cue were incongruent with those of the intended movement. 2. The majority of PMd cells discharged both at short latency to the RD or DD cues and subsequently with sustained activity during the remaining ID period (IDP). The earliest responses (< 250 ms) in both DD and RD trials covaried with cue location and so could be either a "visuospatial" response or a neuronal correlate of the selection of action with highest S-R compatibility, namely move to the stimulus. In contrast, later IDP activity usually covaried with the direction of movement signaled by the cues, independent of their spatial location, supporting the hypothesis that IDP discharge in PMd ultimately encodes attributes of intended reaching movements.

LFP Power Spectra in V1 Cortex: The Graded Effect of Stimulus Contrast

2005 ◽  
Vol 94 (1) ◽  
pp. 479-490 ◽  
Author(s):  
J. Andrew Henrie ◽  
Robert Shapley
Keyword(s):  
Frequency Band ◽  
Power Spectra ◽  
Low Frequency ◽  
Wide Band ◽  
Gamma Band ◽  
Single Units ◽  
Total Power ◽  
Stimulus Contrast ◽  
Stimulus Response ◽  
Gamma Frequency

We recorded local field potentials (LFPs) and single-unit activity simultaneously in the macaque primary visual cortex (V1) and studied their responses to drifting sinusoidal gratings that were chosen to be “optimal” for the single units. Over all stimulus conditions, the LFP spectra have much greater power in the low-frequency band (≤10 Hz) than higher frequencies and can be described as “1/f.” Analysis of the total power limited to the low, gamma (25–90 Hz), or broad (8–240 Hz) frequency bands of the LFP as a function of stimulus contrast indicates that the LFP power gradually increases with stimulus strength across a wide band in a manner roughly comparable to the increase in the simultaneously recorded spike activity. However, the low-frequency band power remains approximately constant across all stimulus contrasts. More specifically the gamma-band LFP power increases differentially more with respect to baseline than either higher or lower bands as stimulus contrast increases. At the highest stimulus contrasts, we report as others have previously, that the power spectrum of the LFP typically contains an obvious peak in the gamma-frequency band. The gamma-band peak emerges from the overall broadband enhancement in LFP power at stimulus contrasts where most single units' responses have begun to saturate. The temporal/spectral structures of the LFP located in the gamma band—which become most evident at the highest contrasts—provide additional constraints on potential mechanisms underlying the stimulus response properties of spiking neurons in V1.

scholarly journals Granule cell excitability regulates gamma and beta oscillations in a model of the olfactory bulb dendrodendritic microcircuit

2016 ◽  
Vol 116 (2) ◽  
pp. 522-539 ◽  
Author(s):  
Bolesław L. Osinski ◽  
Leslie M. Kay
Keyword(s):  
Olfactory Bulb ◽  
Granule Cells ◽  
Field Potential ◽  
Gamma Oscillations ◽  
Causal Link ◽  
Beta Oscillations ◽  
Gamma Frequency ◽  
Voltage Dependent ◽  
Nmda Channels ◽  
Beta Frequency

Odors evoke gamma (40–100 Hz) and beta (20–30 Hz) oscillations in the local field potential (LFP) of the mammalian olfactory bulb (OB). Gamma (and possibly beta) oscillations arise from interactions in the dendrodendritic microcircuit between excitatory mitral cells (MCs) and inhibitory granule cells (GCs). When cortical descending inputs to the OB are blocked, beta oscillations are extinguished whereas gamma oscillations become larger. Much of this centrifugal input targets inhibitory interneurons in the GC layer and regulates the excitability of GCs, which suggests a causal link between the emergence of beta oscillations and GC excitability. We investigate the effect that GC excitability has on network oscillations in a computational model of the MC-GC dendrodendritic network with Ca2+-dependent graded inhibition. Results from our model suggest that when GC excitability is low, the graded inhibitory current mediated by NMDA channels and voltage-dependent Ca2+ channels (VDCCs) is also low, allowing MC populations to fire in the gamma frequency range. When GC excitability is increased, the activation of NMDA receptors and other VDCCs is also increased, allowing the slow decay time constants of these channels to sustain beta-frequency oscillations. Our model argues that Ca2+ flow through VDCCs alone could sustain beta oscillations and that the switch between gamma and beta oscillations can be triggered by an increase in the excitability state of a subpopulation of GCs.

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