scholarly journals Timing in Predictive Coding: The Roles of Task Relevance and Global Probability

2017 ◽  
Vol 29 (5) ◽  
pp. 780-792 ◽  
Author(s):  
Chase Sherwell ◽  
Marta I. Garrido ◽  
Ross Cunnington
Keyword(s):  
A Priori ◽  
Predictive Coding ◽  
Stimulus Onset ◽  
Interactive Effects ◽  
Sensory Stimuli ◽  
Task Relevance ◽  
Temporal Prediction ◽  
Preparatory Activity ◽  
Sensory Responses ◽  
Sensory Neural

Predictive coding models of attention propose that attention and prediction operate synergistically to optimize perception, as reflected in interactive effects on early sensory neural responses. It is yet unclear whether attention and prediction based on the temporal attributes of expected events operate in a similar fashion. We investigated how attention and prediction based on timing interact by manipulating the task relevance and a priori probability of auditory stimulus onset timing within a go/no-go task while recording EEG. Preparatory activity, as indexed via the contingent negative variation, reflected temporally specific anticipation as a function of both attention and prediction. Higher stimulus probability led to significant predictive N1 suppression; however, we failed to find an effect of task relevance on N1 amplitude and an interaction of task relevance with prediction. We suggest the predictability of sensory timing is the predominant influence on early sensory responses where a priori probabilities allow for strong prior beliefs. When this is the case, we find that the effects of temporal prediction on early sensory responses are independent of the task relevance of sensory stimuli. Our findings contribute to the expansion of predictive coding frameworks to include the role of timing in sensory processing.

scholarly journals Individual bitter-sensing neurons in Drosophila exhibit both ON and OFF responses that influence synaptic plasticity

2020 ◽  
Author(s):  
Anita V. Devineni ◽  
Julia U. Deere ◽  
Bei Sun ◽  
Richard Axel
Keyword(s):  
Synaptic Plasticity ◽  
Neural Circuit ◽  
Stimulus Onset ◽  
Response Dynamics ◽  
Taste System ◽  
Sensory Stimuli ◽  
Appropriate Behavior ◽  
Temporal Properties ◽  
Sensory Responses ◽  
Peripheral Sensory

ABSTRACTThe brain creates internal representations that translate sensory stimuli into appropriate behavior. Most studies of sensory processing focus on which subsets of neurons are activated by a stimulus, but the temporal features of the neural response are also important for behavior. In the taste system, the timing of peripheral sensory responses has rarely been examined. We investigated the temporal properties of taste responses in Drosophila melanogaster and discovered that different types of taste sensory neurons show striking differences in their response dynamics. Strong responses to stimulus onset (ON responses) and offset (OFF responses) were observed in bitter-sensing neurons in the labellum, whereas bitter neurons in the leg and other classes of labellar taste neurons showed only an ON response. Individual bitter labellar neurons generate both the ON and OFF responses through a cell-intrinsic mechanism that requires canonical bitter receptors. The bitter ON and OFF responses at the periphery are propagated to dopaminergic neurons that innervate the mushroom body and mediate aversive learning. When bitter is used as a reinforcement cue, the bitter ON and OFF responses can drive opposing types of synaptic plasticity and the effect of the OFF response dominates, likely due to the rapid and preferential habituation of the ON response. Together, these studies characterize novel features of neural responses in the taste system and reveal their importance for neural circuit function.

Temporal Prediction Errors Affect Short-Term Memory Scanning Response Time

2016 ◽  
Vol 63 (6) ◽  
pp. 333-342
Author(s):  
Roberto Limongi ◽  
Angélica M. Silva
Keyword(s):  
Response Time ◽  
Short Term Memory ◽  
Estimation Error ◽  
Predictive Coding ◽  
Time Estimation ◽  
Prediction Errors ◽  
Memory Scanning ◽  
Short Term ◽  
Term Memory ◽  
Temporal Prediction

Abstract. The Sternberg short-term memory scanning task has been used to unveil cognitive operations involved in time perception. Participants produce time intervals during the task, and the researcher explores how task performance affects interval production – where time estimation error is the dependent variable of interest. The perspective of predictive behavior regards time estimation error as a temporal prediction error (PE), an independent variable that controls cognition, behavior, and learning. Based on this perspective, we investigated whether temporal PEs affect short-term memory scanning. Participants performed temporal predictions while they maintained information in memory. Model inference revealed that PEs affected memory scanning response time independently of the memory-set size effect. We discuss the results within the context of formal and mechanistic models of short-term memory scanning and predictive coding, a Bayes-based theory of brain function. We state the hypothesis that our finding could be associated with weak frontostriatal connections and weak striatal activity.

scholarly journals Dependence of the stimulus-driven microsaccade rate signature on visual stimulus polarity

2020 ◽  
Author(s):  
Tatiana Malevich ◽  
Antimo Buonocore ◽  
Ziad M. Hafed
Keyword(s):  
Stimulus Onset ◽  
Neural Mechanisms ◽  
Oculomotor Control ◽  
Background Luminance ◽  
Subsequent Increase ◽  
Rapid Reduction ◽  
Sensory Stimuli ◽  
Gaze Fixation ◽  
Early Access ◽  
Steady Rate

AbstractMicrosaccades have a steady rate of occurrence during maintained gaze fixation, which gets transiently modulated by abrupt sensory stimuli. Such modulation, characterized by a rapid reduction in microsaccade frequency followed by a stronger rebound phase of high microsaccade rate, is often described as the microsaccadic rate signature, owing to its stereotyped nature. Here we investigated the impacts of stimulus polarity (luminance increments or luminance decrements relative to background luminance) and size on the microsaccadic rate signature. We presented brief visual flashes consisting of large or small white or black stimuli over an otherwise gray image background. Both large and small stimuli caused robust early microsaccadic inhibition, but only small ones caused a subsequent increase in microsaccade frequency above baseline microsaccade rate. Critically, small black stimuli were always associated with stronger modulations in microsaccade rate after stimulus onset than small white stimuli, particularly in the post-inhibition rebound phase of the microsaccadic rate signature. Because small stimuli were also associated with expected direction oscillations to and away from their locations of appearance, these stronger rate modulations in the rebound phase meant higher likelihoods of microsaccades opposite the black flash locations relative to the white flash locations. Our results demonstrate that the microsaccadic rate signature is sensitive to stimulus polarity, and they point to dissociable neural mechanisms underlying early microsaccadic inhibition after stimulus onset and later microsaccadic rate rebound at longer times thereafter. These results also demonstrate early access of oculomotor control circuitry to sensory representations, particularly for momentarily inhibiting saccade generation.New and noteworthyMicrosaccades are small saccades that occur during gaze fixation. Microsaccade rate is transiently reduced after sudden stimulus onsets, and then strongly rebounds before returning to baseline. We explored the influence of stimulus polarity (black versus white) on this “rate signature”. We found that small black stimuli cause stronger microsaccadic modulations than white ones, but primarily in the rebound phase. This suggests dissociated neural mechanisms for microsaccadic inhibition and subsequent rebound in the microsaccadic rate signature.

scholarly journals Enhanced Alpha-oscillations in Visual Cortex during Anticipation of Self-generated Visual Stimulation

2014 ◽  
Vol 26 (11) ◽  
pp. 2540-2551 ◽  
Author(s):  
Max-Philipp Stenner ◽  
Markus Bauer ◽  
Patrick Haggard ◽  
Hans-Jochen Heinze ◽  
Ray Dolan
Keyword(s):  
Visual Cortex ◽  
Visual Stimulation ◽  
Sensory Information ◽  
Sensory Stimuli ◽  
Forward Models ◽  
Alpha Oscillations ◽  
Time Frequency ◽  
Sensory Attenuation ◽  
Sensory Neural ◽  
Motor Actions

The perceived intensity of sensory stimuli is reduced when these stimuli are caused by the observer's actions. This phenomenon is traditionally explained by forward models of sensory action–outcome, which arise from motor processing. Although these forward models critically predict anticipatory modulation of sensory neural processing, neurophysiological evidence for anticipatory modulation is sparse and has not been linked to perceptual data showing sensory attenuation. By combining a psychophysical task involving contrast discrimination with source-level time–frequency analysis of MEG data, we demonstrate that the amplitude of alpha-oscillations in visual cortex is enhanced before the onset of a visual stimulus when the identity and onset of the stimulus are controlled by participants' motor actions. Critically, this prestimulus enhancement of alpha-amplitude is paralleled by psychophysical judgments of a reduced contrast for this stimulus. We suggest that alpha-oscillations in visual cortex preceding self-generated visual stimulation are a likely neurophysiological signature of motor-induced sensory anticipation and mediate sensory attenuation. We discuss our results in relation to proposals that attribute generic inhibitory functions to alpha-oscillations in prioritizing and gating sensory information via top–down control.

Seeing Beyond the Nyquist Limit

1992 ◽  
Vol 4 (5) ◽  
pp. 682-690 ◽  
Author(s):  
Daniel L. Ruderman ◽  
William Bialek
Keyword(s):  
A Priori ◽  
Nyquist Frequency ◽  
Regular Array ◽  
Sensory Stimuli ◽  
High Frequencies ◽  
Natural Case ◽  
Receptor Array ◽  
Stimulus Reconstruction ◽  
Nyquist Limit ◽  
Reconstruction Strategy

In many biological systems the primary transduction of sensory stimuli occurs in a regular array of receptors. Because of this discrete sampling it is usually assumed that the organism has no knowledge of signals beyond the Nyquist frequency. In fact, higher frequency signals are expected to mask the available lower frequency information as a result of aliasing. It has been suggested that these considerations are important in understanding, for example, the design of the receptor lattice in the mammalian fovea. We show that if the organism has knowledge of the probability distribution from which the signals are drawn, outputs from a discrete receptor array can be used to estimate signals beyond the Nyquist limit. In effect, a priori knowledge can be used to de-alias the image, and the estimated signal above the Nyquist cutoff is in fact coherent with the real signal at these high frequencies. We address initially the problem of stimulus reconstruction from a noisy receptor array responding to a Gaussian stimulus ensemble. In this case, the best reconstruction strategy is a simple linear transformation. In the more interesting (and natural) case of nongaussian stimuli, optimal reconstruction requires nonlinear operations, but the higher order correlations in the stimulus ensemble can be used to improve the estimate of super-Nyquist signals.

Behavioral Time Course of Microstimulation in Cortical Area MT

2010 ◽  
Vol 103 (1) ◽  
pp. 334-345 ◽  
Author(s):  
Nicolas Y. Masse ◽  
Erik P. Cook
Keyword(s):  
Electrical Stimulation ◽  
Time Course ◽  
Behavioral Effects ◽  
Sensory Stimuli ◽  
Temporal Properties ◽  
Behavioral Studies ◽  
Electrophysiological Studies ◽  
Excitatory Component ◽  
Sensory Neural

Electrical stimulation of the brain is a valuable research tool and has shown therapeutic promise in the development of new sensory neural prosthetics. Despite its widespread use, we still do not fully understand how current passed through a microelectrode interacts with functioning neural circuits. Past behavioral studies have suggested that weak electrical stimulation (referred to as microstimulation) of sensory areas of cortex produces percepts that are similar to those generated by normal sensory stimuli. In contrast, electrophysiological studies using in vitro or anesthetized preparations have shown that neural activity produced by brief microstimulation is radically different and longer lasting than normal responses. To help reconcile these two aspects of microstimulation, we examined the temporal properties that microstimulation has on visual perception. We found that brief application of subthreshold microstimulation in the middle temporal (MT) area of visual cortex produced smaller and longer-lasting effects on motion perception compared with an equivalent visual stimulus. In agreement with past electrophysiological studies, a computer simulation reproduced our behavioral effects when the time course of a single microstimulation pulse was modeled with three components: an immediate fast strong excitatory component, followed by a weaker inhibitory component, and then followed by a long duration weak excitatory component. Overall, these results suggest the behavioral effects of microstimulation in our experiments were caused by the unique and long-lasting temporal effects microstimulation has on functioning cortical circuits.

scholarly journals Motor-induced Suppression of the Auditory Cortex

2009 ◽  
Vol 21 (4) ◽  
pp. 791-802 ◽  
Author(s):  
Sheye O. Aliu ◽  
John F. Houde ◽  
Srikantan S. Nagarajan
Keyword(s):  
Auditory Cortex ◽  
Auditory System ◽  
Somatosensory System ◽  
Motor Command ◽  
Stimulus Onset ◽  
Button Press ◽  
Motor Processing ◽  
Sensory Motor ◽  
Sensory Responses ◽  
And Control

Sensory responses to stimuli that are triggered by a self-initiated motor act are suppressed when compared with the response to the same stimuli triggered externally, a phenomenon referred to as motor-induced suppression (MIS) of sensory cortical feedback. Studies in the somatosensory system suggest that such suppression might be sensitive to delays between the motor act and the stimulus onset, and a recent study in the auditory system suggests that such MIS develops rapidly. In three MEG experiments, we characterize the properties of MIS by examining the M100 response from the auditory cortex to a simple tone triggered by a button press. In Experiment 1, we found that MIS develops for zero delays but does not generalize to nonzero delays. In Experiment 2, we found that MIS developed for 100-msec delays within 300 trials and occurs in excess of auditory habituation. In Experiment 3, we found that unlike MIS for zero delays, MIS for nonzero delays does not exhibit sensitivity to sensory, delay, or motor-command changes. These results are discussed in relation to suppression to self-produced speech and a general model of sensory motor processing and control.

Facilitating Sensory Responses in Developing Mouse Somatosensory Barrel Cortex

2007 ◽  
Vol 97 (4) ◽  
pp. 2992-3003 ◽  
Author(s):  
Aren J. Borgdorff ◽  
James F. A. Poulet ◽  
Carl C. H. Petersen
Keyword(s):  
Barrel Cortex ◽  
Cortical Excitability ◽  
Sensory Response ◽  
Cortical Circuits ◽  
Pharmacological Agents ◽  
Sensory Stimuli ◽  
Early Postnatal Development ◽  
Sensory Responses ◽  
Activity Dependent ◽  
Whole Cell Recordings

The sensory responses in the barrel cortex of mice aged postnatal day (P)7–P12 evoked by a single whisker deflection are smaller in amplitude and spread over a smaller area than those measured in P13–P21 mice. However, repetitive 10-Hz stimulation or paired pulse whisker stimulation in P7–P12 mice evoked facilitating sensory responses, contrasting with the depressing sensory responses observed in P13–P21 mice. This facilitation occurred during an interval ranging 300–1,000 ms after the first stimulus and was measured using whole cell recordings, voltage-sensitive dye imaging, and calcium-sensitive dye imaging. The facilitated responses were not only larger in amplitude but also propagated over a larger cortical area. The facilitation could be blocked by local application of pharmacological agents reducing cortical excitability. Local cortical microstimulation could substitute for the first whisker stimulus to produce a facilitated sensory response. The enhanced sensory responses evoked by repetitive sensory stimuli in P7–P12 mice may contribute to the activity-dependent specification of the developing cortical circuits. In addition, the facilitating sensory responses allow long integration times for sensory processing compatible with the slow behavior of mice during early postnatal development.

scholarly journals A novel mechanism for amplification of sensory responses by the amygdala-TRN projections

2019 ◽  
Author(s):  
Mark Aizenberg ◽  
Solymar Rolon Martinez ◽  
Tuan Pham ◽  
Winnie Rao ◽  
Julie Haas ◽  
...  
Keyword(s):  
Basolateral Amygdala ◽  
Auditory Pathway ◽  
Emotional Learning ◽  
Evoked Responses ◽  
Sensory Stimuli ◽  
Environmental Signals ◽  
Neuropsychological Disorders ◽  
Sensory Responses ◽  
Evoked Activity ◽  
Central Auditory Pathway

AbstractMany forms of behavior require selective amplification of neuronal representations of relevant environmental signals. Following emotional learning, sensory stimuli drive enhanced responses in the sensory cortex. However, the brain circuits that underlie emotionally driven control of the sensory representations remain poorly understood. Here we identify a novel pathway between the basolateral amygdala (BLA), an emotional learning center in the mouse brain, and the inhibitory nucleus of the thalamus (TRN). We demonstrate that activation of this pathway amplifies sound-evoked activity in the central auditory pathway. Optogenetic activation of BLA suppressed spontaneous, but not tone-evoked activity in the auditory cortex (AC), effectively amplifying tone-evoked responses in AC. Anterograde and retrograde viral tracing identified robust BLA projections terminating at TRN. Optogenetic activation of amygdala-TRN pathway mimicked the effect of direct BLA activation, amplifying tone-evoked responses in the auditory thalamus and cortex. The results are explained by a computational model of the thalamocortical circuitry. In our model, activation of TRN by BLA suppresses spontaneous activity in thalamocortical cells, and as a result, thalamocortical neurons are primed to relay relevant sensory input. These results demonstrate a novel circuit mechanism for shining a neural spotlight on behaviorally relevant signals and provide a potential target for treatment of neuropsychological disorders, in which emotional control of sensory processing is disrupted.

scholarly journals Similarities Between Somatosensory Cortical Responses Induced via Natural Touch and Microstimulation in the Ventral Posterior Lateral Thalamus in Macaques

2021 ◽  
Author(s):  
Joseph T Francis ◽  
Anna Rozenboym ◽  
Lee von Kraus ◽  
Shaohua Xu ◽  
Pratik Chhatbar ◽  
...  
Keyword(s):  
Somatosensory System ◽  
Sensory Information ◽  
Rodent Model ◽  
Robotic Arm ◽  
Neural Responses ◽  
Sensory Stimuli ◽  
Thalamic Stimulation ◽  
Cortical Responses ◽  
The Difference ◽  
Sensory Neural

Lost sensations, such as touch, could be restored by microstimulation (MiSt) along the sensory neural substrate. Such neuroprosthetic sensory information can be used as feedback from an invasive brain-machine interface (BMI) to control a robotic arm/hand, such that tactile and proprioceptive feedback from the sensorized robotic arm/hand is directly given to the BMI user. Microstimulation in the human somatosensory thalamus (Vc) has been shown to produce somatosensory perceptions. However, until recently, systematic methods for using thalamic stimulation to evoke naturalistic touch perceptions were lacking. We have recently presented rigorous methods for determining a mapping between ventral posterior lateral thalamus (VPL) MiSt, and neural responses in the somatosensory cortex (S1), in a rodent model (Choi et al., 2016; Choi and Francis, 2018). Our technique minimizes the difference between S1 neural responses induced by natural sensory stimuli and those generated via VPL MiSt. Our goal is to develop systems that know what MiSt will produce a given neural response and possibly a more natural "sensation." To date, our optimization has been conducted in the rodent model and simulations. Here we present data from simple non-optimized thalamic MiSt during peri-operative experiments, where we MiSt in the VPL of macaques with a somatosensory system more like humans. We implanted arrays of microelectrodes across the hand area of the macaque S1 cortex as well as in the VPL thalamus. Multi and single-unit recordings were used to compare cortical responses to natural touch and thalamic MiSt in the anesthetized state. Post stimulus time histograms were highly correlated between the VPL MiSt and natural touch modalities, adding support to the use of VPL MiSt towards producing a somatosensory neuroprosthesis in humans.

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