scholarly journals Evidence accumulation determines conscious access

2020 ◽  
Author(s):  
Michael Pereira ◽  
Pierre Megevand ◽  
Mi Xue Tan ◽  
Wenwen Chang ◽  
Shuo Wang ◽  
...  
Keyword(s):  
Posterior Parietal Cortex ◽  
Detection Threshold ◽  
Neuron Activity ◽  
Neural Responses ◽  
Neuronal Dynamics ◽  
Perceptual Consciousness ◽  
Evidence Accumulation ◽  
Stimulus Detection ◽  
Posterior Parietal ◽  
Task Irrelevant

A fundamental scientific question concerns the neuronal basis of perceptual consciousness, which encompasses the perceptual experience and reflexive monitoring associated with a sensory event. Although recent human studies identified individual neurons reflecting stimulus visibility, their functional role for perceptual consciousness remains unknown. Here, we provide neuronal and computational evidence indicating that perceptual and reflexive consciousness are governed by an all-or-none process involving accumulation of perceptual evidence. We recorded single-neuron activity in a participant with a microelectrode implant in the posterior parietal cortex, considered a substrate for evidence accumulation, while he detected vibrotactile stimuli around detection threshold and provided confidence estimates. We found that detected stimuli elicited firing rate patterns resembling evidence accumulation during decision-making, irrespective of response effectors. Similar neurons encoded the intensity of task-irrelevant stimuli, suggesting their role for consciousness per se, irrespective of report. We generalized these findings in healthy volunteers using electroencephalography and reproduced their behavioral and neural responses with a computational model. This model considered stimulus detection if accumulated evidence reached a bound, and confidence as the distance between maximal evidence and that bound. Applying this mechanism to our neuronal data, we were able to decode single-trial confidence ratings both for detected and undetected stimuli. Our results show that the specific gradual changes in neuronal dynamics during evidence accumulation govern perceptual consciousness and reflexive monitoring in humans.

scholarly journals Evidence accumulation relates to perceptual consciousness and monitoring

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Michael Pereira ◽  
Pierre Megevand ◽  
Mi Xue Tan ◽  
Wenwen Chang ◽  
Shuo Wang ◽  
...  
Keyword(s):  
Posterior Parietal Cortex ◽  
Detection Threshold ◽  
Task Demands ◽  
Neuron Activity ◽  
Neural Responses ◽  
Neuronal Responses ◽  
Neural Basis ◽  
Perceptual Consciousness ◽  
Evidence Accumulation ◽  
Posterior Parietal

AbstractA fundamental scientific question concerns the neural basis of perceptual consciousness and perceptual monitoring resulting from the processing of sensory events. Although recent studies identified neurons reflecting stimulus visibility, their functional role remains unknown. Here, we show that perceptual consciousness and monitoring involve evidence accumulation. We recorded single-neuron activity in a participant with a microelectrode in the posterior parietal cortex, while they detected vibrotactile stimuli around detection threshold and provided confidence estimates. We find that detected stimuli elicited neuronal responses resembling evidence accumulation during decision-making, irrespective of motor confounds or task demands. We generalize these findings in healthy volunteers using electroencephalography. Behavioral and neural responses are reproduced with a computational model considering a stimulus as detected if accumulated evidence reaches a bound, and confidence as the distance between maximal evidence and that bound. We conclude that gradual changes in neuronal dynamics during evidence accumulation relates to perceptual consciousness and perceptual monitoring in humans.

scholarly journals Precision and neuronal dynamics in the human posterior parietal cortex during evidence accumulation

NeuroImage ◽  
2015 ◽  
Vol 107 ◽  
pp. 219-228 ◽  
Author(s):  
Thomas H.B. FitzGerald ◽  
Rosalyn J. Moran ◽  
Karl J. Friston ◽  
Raymond J. Dolan
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Neuronal Dynamics ◽  
Evidence Accumulation ◽  
Posterior Parietal

scholarly journals Distinct effects of prefrontal and parietal cortex inactivations on an accumulation of evidence task in the rat

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Jeffrey C Erlich ◽  
Bingni W Brunton ◽  
Chunyu A Duan ◽  
Timothy D Hanks ◽  
Carlos D Brody
Keyword(s):  
Decision Making ◽  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Neural Correlates ◽  
Brain Regions ◽  
Integration Time ◽  
Detailed Model ◽  
Evidence Accumulation ◽  
Posterior Parietal ◽  
Cortical Regions

Numerous brain regions have been shown to have neural correlates of gradually accumulating evidence for decision-making, but the causal roles of these regions in decisions driven by accumulation of evidence have yet to be determined. Here, in rats performing an auditory evidence accumulation task, we inactivated the frontal orienting fields (FOF) and posterior parietal cortex (PPC), two rat cortical regions that have neural correlates of accumulating evidence and that have been proposed as central to decision-making. We used a detailed model of the decision process to analyze the effect of inactivations. Inactivation of the FOF induced substantial performance impairments that were quantitatively best described as an impairment in the output pathway of an evidence accumulator with a long integration time constant (>240 ms). In contrast, we found a minimal role for PPC in decisions guided by accumulating auditory evidence, even while finding a strong role for PPC in internally-guided decisions.

scholarly journals Causal contribution and dynamical encoding in the striatum during evidence accumulation

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Michael M Yartsev ◽  
Timothy D Hanks ◽  
Alice Misun Yoon ◽  
Carlos D Brody
Keyword(s):  
Decision Making ◽  
Posterior Parietal Cortex ◽  
Dorsal Striatum ◽  
Neural Encoding ◽  
Evidence Accumulation ◽  
Decision Making Processes ◽  
Posterior Parietal ◽  
Gradual Accumulation ◽  
Cortical Regions ◽  
Decision Making Behavior

A broad range of decision-making processes involve gradual accumulation of evidence over time, but the neural circuits responsible for this computation are not yet established. Recent data indicate that cortical regions that are prominently associated with accumulating evidence, such as the posterior parietal cortex and the frontal orienting fields, may not be directly involved in this computation. Which, then, are the regions involved? Regions that are directly involved in evidence accumulation should directly influence the accumulation-based decision-making behavior, have a graded neural encoding of accumulated evidence and contribute throughout the accumulation process. Here, we investigated the role of the anterior dorsal striatum (ADS) in a rodent auditory evidence accumulation task using a combination of behavioral, pharmacological, optogenetic, electrophysiological and computational approaches. We find that the ADS is the first brain region known to satisfy the three criteria. Thus, the ADS may be the first identified node in the network responsible for evidence accumulation.

scholarly journals Action representation in the mouse parieto-frontal network

2019 ◽  
Author(s):  
Tuce Tombaz ◽  
Benjamin A. Dunn ◽  
Karoline Hovde ◽  
Ryan J. Cubero ◽  
Bartul Mimica ◽  
...  
Keyword(s):  
Mirror Neurons ◽  
Posterior Parietal Cortex ◽  
Wheel Running ◽  
Action Representation ◽  
Neural Responses ◽  
Brain Areas ◽  
Neural Ensembles ◽  
Sensorimotor Transformations ◽  
Posterior Parietal ◽  
Goal Directed Behavior

AbstractThe posterior parietal cortex (PPC), along with anatomically linked frontal areas, form a cortical network which mediates several functions that support goal-directed behavior, including sensorimotor transformations and decision making. In primates, this network also links performed and observed actions via mirror neurons, which fire both when an individual performs an action and when they observe the same action performed by a conspecific. Mirror neurons are thought to be important for social learning and imitation, but it is not known whether mirror-like neurons occur in similar networks in other species that can learn socially, such as rodents. We therefore imaged Ca2+ responses in large neural ensembles in PPC and secondary motor cortex (M2) while mice performed and observed several actions in pellet reaching and wheel running tasks. In all animals, we found spatially overlapping neural ensembles in PPC and M2 that robustly encoded a variety of naturalistic behaviors, and that subsets of cells could stably encode multiple actions. However, neural responses to the same set of observed actions were absent in both brain areas, and across animals. Statistical modeling analyses also showed that performed actions, especially those that were task-specific, outperformed observed actions in predicting neural responses. Overall, these findings show that performed and observed actions do not drive the same cells in the parieto-frontal network in mice, and suggest that sensorimotor mirroring in the mammalian cortex may have evolved more recently, and only in certain species.

scholarly journals Evidence for differential top-down and bottom-up suppression in posterior parietal cortex

2013 ◽  
Vol 368 (1628) ◽  
pp. 20130069 ◽  
Author(s):  
Koorosh Mirpour ◽  
James W. Bisley
Keyword(s):  
Neural Activity ◽  
Posterior Parietal Cortex ◽  
Top Down ◽  
Bottom Up ◽  
Irrelevant Distractors ◽  
Posterior Parietal ◽  
Physically Identical ◽  
Task Irrelevant ◽  
Foraging Task ◽  
Single Unit Response

When searching for an object, we usually avoid items that are visually different from the target and objects or places that have been searched already. Previous studies have shown that neural activity in the lateral intraparietal area (LIP) can be used to guide this behaviour; responses to task irrelevant stimuli or to stimuli that have been fixated previously in the trial are reduced compared with responses to potential targets. Here, we test the hypothesis that these reduced responses have a different genesis. Two animals were trained on a visual foraging task, in which they had to find a target among a number of physically identical potential targets (T) and task irrelevant distractors. We recorded neural activity and local field potentials (LFPs) in LIP while the animals performed the task. We found that LFP power was similar for potential targets and distractors but was greater in the alpha and low beta bands when a previously fixated T was in the response field. We interpret these data to suggest that the reduced single-unit response to distractors is a bottom-up feed-forward result of processing in earlier areas and the reduced response to previously fixated Ts is a result of active top-down suppression.

scholarly journals Distinct behavioral effects of prefrontal and parietal cortex inactivations on an accumulation of evidence task in the rat

2014 ◽  
Author(s):  
Jeffrey C Erlich ◽  
Bingni W Brunton ◽  
Chunyu A Duan ◽  
Timothy D Hanks ◽  
Carlos D Brody
Keyword(s):  
Decision Making ◽  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Neural Correlates ◽  
Brain Regions ◽  
Integration Time ◽  
Detailed Model ◽  
Evidence Accumulation ◽  
Posterior Parietal ◽  
Cortical Regions

Numerous brain regions have been shown to have neural correlates of gradually accumulating evidence for decision-making, but the causal roles of these regions in decisions driven by accumulation of evi- dence have yet to be determined. Here, in rats performing an auditory evidence accumulation task, we inactivated the frontal orienting fields (FOF) and posterior parietal cortex (PPC), two rat cortical regions that have neural correlates of accumulating evidence and that have been proposed as central to decision-making. We used a detailed model of the decision process to analyze the effect of inactivations. Inactivation of the FOF induced substantial performance impairments that were quantitatively best de- scribed as an impairment in the output pathway of an evidence accumulator with a long integration time constant (>240ms). In contrast, we found a minimal role for PPC in decisions guided by accumulating auditory evidence, even while finding a strong role for PPC in internally-guided decisions.

scholarly journals Neural population dynamics underlying evidence accumulation in multiple rat brain regions

2021 ◽  
Author(s):  
Brian DePasquale ◽  
Jonathan W Pillow ◽  
Carlos Brody
Keyword(s):  
Decision Making ◽  
Neural Activity ◽  
Posterior Parietal Cortex ◽  
Dorsal Striatum ◽  
Brain Regions ◽  
Neural Representation ◽  
Neural Population ◽  
Evidence Accumulation ◽  
Posterior Parietal ◽  
The Moment

Accumulating evidence in service of sensory decision making is a core cognitive function. However, previous work has focused either on the dynamics of neural activity during decision-making or on models of evidence accumulation governing behavior. We unify these two perspectives by introducing an evidence-accumulation framework that simultaneously describes multi-neuron population spiking activity and dynamic stimulus-driven behavior during sensory decision-making. We apply our method to behavioral choices and neural activity recorded from three brain regions - the posterior parietal cortex (PPC), the frontal orienting fields (FOF), and the anterior-dorsal striatum (ADS) - while rats performed a pulse-based accumulation task. The model accurately captures the relationship between stimuli and neural activity, the coordinated activity of neural populations, and the distribution of animal choices in response to the stimulus. Model fits show strikingly distinct accumulation models expressed within each brain region, and that all differ strongly from the accumulation strategy expressed at the level of choices. In particular, the FOF exhibited a suboptimal 'primacy' strategy, where early sensory evidence was favored. Including neural data in the model led to improved prediction of the moment-by-moment value of accumulated evidence and the intended-and ultimately made-choice of the animal. Our approach offers a window into the neural representation of accumulated evidence and provides a principled framework for incorporating neural responses into accumulation models.

fMRI neural activation patterns induced by professional military training

2012 ◽  
Vol 3 (1) ◽  
Author(s):  
Krešimir Ćosić ◽  
Siniša Popović ◽  
Ivan Fabek ◽  
Bernard Kovač ◽  
Milan Radoš ◽  
...  
Keyword(s):  
Posterior Parietal Cortex ◽  
Military Training ◽  
Temporal Cortex ◽  
Well Being ◽  
Neural Activation ◽  
Neural Responses ◽  
Activation Patterns ◽  
Operational Capabilities ◽  
Posterior Parietal ◽  
Potential Failure

AbstractProfessional military training makes tough demands on soldiers’ perceptual and motor skills, as well as on their physical fitness and cognitive capabilities in the course of preparation for stressful operational environments. In this pilot study we attempted to identify difference in pattern of neural responses between extensively trained, professional mission-ready soldiers and novice soldiers during audiovisual simulation of mission conditions. We performed fMRI scanning on a few volunteers during presentation of semantically relevant video-clips of real combat from Afghanistan to evaluate influence of military training on mental responses of soldiers. We showed that for professional mission-ready soldiers a week before their deployment to Afghanistan, videoclips with deadly ambush combat induce greater overall brain activation compared to novice soldiers. Missionready soldiers showed greater activation in premotor/prefrontal cortex, posterior parietal cortex, and posterior temporal cortex. These results imply that fMRI technique could be used as challenging step forward in the multidimensional evaluation of military training influence on neural responses and operational capabilities of professional soldiers. This is extremely important not only for potential failure prevention and mere success of the mission, but even more for the survival and the well-being of the servicemen and servicewomen.

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