scholarly journals Breaking Deadlocks: Reward Probability and Spontaneous Preference Shape Voluntary Decisions and Electrophysiological Signals in Humans

2020 ◽  
Author(s):  
Wojciech Zajkowski ◽  
Dominik Krzemiński ◽  
Jacopo Barone ◽  
Lisa H. Evans ◽  
Jiaxiang Zhang
Keyword(s):  
Computational Modelling ◽  
Event Related Potentials ◽  
Stimulus Onset ◽  
Rate Of Change ◽  
Optimal Decision ◽  
Time Resolved ◽  
Reward Probability ◽  
Binary Choices ◽  
Related Potentials ◽  
Eeg Recordings

AbstractChoosing between equally valued options is a common conundrum, for which classical decision theories predicted a prolonged response time (RT). This contrasts with the notion that an optimal decision maker in a stable environment should make fast and random choices, as the outcomes are indifferent. Here, we characterize the neurocognitive processes underlying such voluntary decisions by integrating cognitive modelling of behavioral responses and EEG recordings in a probabilistic reward task. Human participants performed binary choices between pairs of unambiguous cues associated with identical reward probabilities at different levels. Higher reward probability accelerated RT, and participants chose one cue faster and more frequent over the other at each probability level. The behavioral effects on RT persisted in simple reactions to single cues. By using hierarchical Bayesian parameter estimation for an accumulator model, we showed that the probability and preference effects were independently associated with changes in the speed of evidence accumulation, but not with visual encoding or motor execution latencies. Time-resolved MVPA of EEG-evoked responses identified significant representations of reward certainty and preference as early as 120 ms after stimulus onset, with spatial relevance patterns maximal in middle central and parietal electrodes. Furthermore, EEG-informed computational modelling showed that the rate of change between N100 and P300 event-related potentials modulated accumulation rates on a trial-by-trial basis. Our findings suggest that reward probability and spontaneous preference collectively shape voluntary decisions between equal options, providing a mechanism to prevent indecision or random behavior.

scholarly journals Reward certainty and preference bias selectively shape voluntary decisions

2019 ◽  
Author(s):  
Wojciech Zajkowski ◽  
Dominik Krzemiński ◽  
Jacopo Barone ◽  
Lisa Evans ◽  
Jiaxiang Zhang
Keyword(s):  
Computational Modelling ◽  
Event Related Potentials ◽  
Stimulus Onset ◽  
Rate Of Change ◽  
Time Resolved ◽  
Evidence Accumulation ◽  
Visual Encoding ◽  
Certainty Level ◽  
Related Potentials ◽  
Human Participants

AbstractChoosing between equally valued options can be a conundrum, for which classical decision theories predicted a prolonged response time (RT). Paradoxically, a rational decision-maker would need no deliberative thinking in this scenario, as outcomes of alternatives are indifferent. How individuals choose between equal options remain unclear. Here, we characterized the neurocognitive processes underlying such voluntary decisions, by integrating advanced cognitive modelling and EEG recording in a probabilistic reward task, in which human participants chose between pairs of cues associated with identical reward probabilities at different levels. We showed that higher reward certainty accelerated RT. At each certainty level, participants preferred to choose one cue faster and more frequently over the other. The behavioral effects on RT persisted in simple reactions to reward cues. By using hierarchical Bayesian parameter estimation for an accumulator model, we showed that the certainty and preference effects were independently associated with the rate of evidence accumulation during decisions, but not with visual encoding or motor execution latencies. Time-resolved multivariate pattern classification of EEG evoked response identified significant representations of reward certainty and preference choices as early as 120 ms after stimulus onset, with spatial relevance patterns maximal in middle central and parietal electrodes. Furthermore, EEG-informed computational modelling showed that the rate of change between N100 and P300 event-related potentials reflected changes in the model-derived rate of evidence accumulation on a trial-by-trial basis. Our findings suggested that reward certainty and preference collectively shaped voluntary decisions between equal options, providing a mechanism to prevent indecision or random behavior.

Orienting and Focusing in Voluntary and Involuntary Visuospatial Attention Conditions

2010 ◽  
Vol 24 (3) ◽  
pp. 198-209 ◽  
Author(s):  
Yan Wang ◽  
Jianhui Wu ◽  
Shimin Fu ◽  
Yuejia Luo
Keyword(s):  
Gain Control ◽  
Event Related Potentials ◽  
Stimulus Onset ◽  
Orientation Discrimination ◽  
Involuntary Attention ◽  
Attention Condition ◽  
Voluntary Attention ◽  
Visual Spatial ◽  
Related Potentials ◽  
Underlying Mechanisms

In the present study, we used event-related potentials (ERPs) and behavioral measurements in a peripherally cued line-orientation discrimination task to investigate the underlying mechanisms of orienting and focusing in voluntary and involuntary attention conditions. Informative peripheral cue (75% valid) with long stimulus onset asynchrony (SOA) was used in the voluntary attention condition; uninformative peripheral cue (50% valid) with short SOA was used in the involuntary attention condition. Both orienting and focusing were affected by attention type. Results for attention orienting in the voluntary attention condition confirmed the “sensory gain control theory,” as attention enhanced the amplitude of the early ERP components, P1 and N1, without latency changes. In the involuntary attention condition, compared with invalid trials, targets in the valid trials elicited larger and later contralateral P1 components, and smaller and later contralateral N1 components. Furthermore, but only in the voluntary attention condition, targets in the valid trials elicited larger N2 and P3 components than in the invalid trials. Attention focusing in the involuntary attention condition resulted in larger P1 components elicited by targets in small-cue trials compared to large-cue trials, whereas in the voluntary attention condition, larger P1 components were elicited by targets in large-cue trials than in small-cue trials. There was no interaction between orienting and focusing. These results suggest that orienting and focusing of visual-spatial attention are deployed independently regardless of attention type. In addition, the present results provide evidence of dissociation between voluntary and involuntary attention during the same task.

scholarly journals Characterizing pinprick-evoked brain potentials before and after experimentally induced secondary hyperalgesia

2015 ◽  
Vol 114 (5) ◽  
pp. 2672-2681 ◽  
Author(s):  
Emanuel N. van den Broeke ◽  
André Mouraux ◽  
Antonia H. Groneberg ◽  
Doreen B. Pfau ◽  
Rolf-Detlef Treede ◽  
...  
Keyword(s):  
Event Related Potentials ◽  
Stimulus Onset ◽  
Secondary Hyperalgesia ◽  
Brain Potentials ◽  
Nociceptive Pathways ◽  
Before And After ◽  
Pain Ratings ◽  
Related Potentials ◽  
Positive Complex ◽  
Stimulation Of

Secondary hyperalgesia is believed to be a key feature of “central sensitization” and is characterized by enhanced pain to mechanical nociceptive stimuli. The aim of the present study was to characterize, using EEG, the effects of pinprick stimulation intensity on the magnitude of pinprick-elicited brain potentials [event-related potentials (ERPs)] before and after secondary hyperalgesia induced by intradermal capsaicin in humans. Pinprick-elicited ERPs and pinprick-evoked pain ratings were recorded in 19 healthy volunteers, with mechanical pinprick stimuli of varying intensities (0.25-mm probe applied with a force extending between 16 and 512 mN). The recordings were performed before (T0) and 30 min after (T1) intradermal capsaicin injection. The contralateral noninjected arm served as control. ERPs elicited by stimulation of untreated skin were characterized by 1) an early-latency negative-positive complex peaking between 120 and 250 ms after stimulus onset (N120-P240) and maximal at the vertex and 2) a long-lasting positive wave peaking 400–600 ms after stimulus onset and maximal more posterior (P500), which was correlated to perceived pinprick pain. After capsaicin injection, pinprick stimuli were perceived as more intense in the area of secondary hyperalgesia and this effect was stronger for lower compared with higher stimulus intensities. In addition, there was an enhancement of the P500 elicited by stimuli of intermediate intensity, which was significant for 64 mN. The other components of the ERPs were unaffected by capsaicin. Our results suggest that the increase in P500 magnitude after capsaicin is mediated by facilitated mechanical nociceptive pathways.

scholarly journals Cognitive Changes in Conjunctive Rule-Based Category Learning: An ERP Approach

2017 ◽  
Author(s):  
Rahel Rabi ◽  
Marc F Joanisse ◽  
Tianshu Zhu ◽  
John Paul Minda
Keyword(s):  
Working Memory ◽  
Category Learning ◽  
Computational Modelling ◽  
Learning Rule ◽  
Event Related Potentials ◽  
Cognitive Changes ◽  
Rule Based ◽  
Differential Processing ◽  
Conjunctive Rule ◽  
Related Potentials

PreprintWhen learning rule-based categories, sufficient cognitive resources are needed to test hypotheses, maintain the currently active rule in working memory, update rules after feedback, and to select a new rule if necessary. Prior research has demonstrated that conjunctive rules are more complex than unidimensional rules and place greater demands on executive functions like working memory. In our study, event-related potentials (ERPs) were recorded while participants performed a conjunctive rule-based category learning task with trial-by-trial feedback. In line with prior research, correct categorization responses resulted in a larger stimulus-locked late positive complex compared to incorrect responses, possibly indexing the updating of rule information in memory. Incorrect trials elicited a pronounced feedback-locked P300 elicited which suggested a disconnect between perception, and the rule-based strategy. We also examined the differential processing of stimuli that were able to be correctly classified by the suboptimal single-dimensional rule (“easy” stimuli) versus those that could only be correctly classified by the optimal, conjunctive rule (“difficult” stimuli). Among strong learners, a larger, late positive slow wave emerged for difficult compared to easy stimuli, suggesting differential processing of category items even though strong learners performed well on the conjunctive category set. Overall, the findings suggest that ERP combined with computational modelling can be used to better understand the cognitive processes involved in rule-based category learning

Duration Estimation of Angry and Neutral Faces: Behavioral and Electrophysiological Correlates

2020 ◽  
Vol 8 (3-4) ◽  
pp. 254-278
Author(s):  
Lisa V. Eberhardt ◽  
Ferdinand Pittino ◽  
Anna Scheins ◽  
Anke Huckauf ◽  
Markus Kiefer ◽  
...  
Keyword(s):  
Emotional Processing ◽  
Event Related Potentials ◽  
Stimulus Onset ◽  
Emotional Stimuli ◽  
Information Processing Model ◽  
Emotional Faces ◽  
Early Posterior Negativity ◽  
Related Potentials ◽  
Stimulus Offset ◽  
Duration Estimation

Abstract Emotional stimuli like emotional faces have been frequently shown to be temporally overestimated compared to neutral ones. This effect has been commonly explained by induced arousal caused by emotional processing leading to the acceleration of an inner-clock-like pacemaker. However, there are some studies reporting contradictory effects and others point to relevant moderating variables. Given this controversy, we aimed at investigating the processes underlying the temporal overestimation of emotional faces by combining behavioral and electrophysiological correlates in a temporal bisection task. We assessed duration estimation of angry and neutral faces using anchor durations of 400 ms and 1600 ms while recording event-related potentials. Subjective ratings and the early posterior negativity confirmed encoding and processing of stimuli’s emotionality. However, temporal ratings did not differ between angry and neutral faces. In line with this behavioral result, the Contingent Negative Variation (CNV), an electrophysiological index of temporal accumulation, was not modulated by the faces’ emotionality. Duration estimates, i.e., short or long responses toward stimuli of ambiguous durations of 1000 ms, were nevertheless associated with a differential CNV amplitude. Interestingly, CNV modulation was already observed at 600–700 ms after stimulus onset, i.e., long before stimulus offset. The results are discussed in light of the information-processing model of time perception as well as regarding possible factors of the experimental setup moderating temporal overestimation of emotional stimuli. In sum, combining behavioral and electrophysiological measures seems promising to more clearly understand the complex processes leading to the illusion of temporal lengthening of emotional faces.

Comparison of Early Cortical Networks in Efficient and Inefficient Visual Search: An Event-Related Potential Study

2003 ◽  
Vol 15 (7) ◽  
pp. 1039-1051 ◽  
Author(s):  
Ute Leonards ◽  
Julie Palix ◽  
Christoph Michel ◽  
Vicente Ibanez
Keyword(s):  
Event Related Potentials ◽  
Temporal Correlation ◽  
Temporal Analysis ◽  
Search Display ◽  
Stimulus Onset ◽  
Event Related Potential ◽  
Time Range ◽  
Cortical Networks ◽  
Related Potentials ◽  
Spatio Temporal

Functional magnetic resonance imaging studies have indicated that efficient feature search (FS) and inefficient conjunction search (CS) activate partially distinct frontoparietal cortical networks. However, it remains a matter of debate whether the differences in these networks reflect differences in the early processing during FS and CS. In addition, the relationship between the differences in the networks and spatial shifts of attention also remains unknown. We examined these issues by applying a spatio-temporal analysis method to high-resolution visual event-related potentials (ERPs) and investigated how spatio-temporal activation patterns differ for FS and CS tasks. Within the first 450 msec after stimulus onset, scalp potential distributions (ERP maps) revealed 7 different electric field configurations for each search task. Configuration changes occurred simultaneously in the two tasks, suggesting that contributing processes were not significantly delayed in one task compared to the other. Despite this high spatial and temporal correlation, two ERP maps (120–190 and 250–300 msec) differed between the FS and CS. Lateralized distributions were observed only in the ERP map at 250–300 msec for the FS. This distribution corresponds to that previously described as the N2pc component (a negativity in the time range of the N2 complex over posterior electrodes of the hemisphere contralateral to the target hemifield), which has been associated with the focusing of attention onto potential target items in the search display. Thus, our results indicate that the cortical networks involved in feature and conjunction searching partially differ as early as 120 msec after stimulus onset and that the differences between the networks employed during the early stages of FS and CS are not necessarily caused by spatial attention shifts.

Intermodal Compensatory Effects in a Visual Search Task with Congenitally Deaf Adults

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 147-147
Author(s):  
P Stivalet ◽  
Y Moreno ◽  
C Cian ◽  
J Richard ◽  
P-A Barraud
Keyword(s):  
New York ◽  
Visual Search ◽  
Search Task ◽  
Visual Search Task ◽  
Event Related Potentials ◽  
Normal Subjects ◽  
Stimulus Onset ◽  
Search Pattern ◽  
York Academy ◽  
Related Potentials

In a visual search paradigm we measured the stimulus onset asynchrony (SOA) between a stimulus and a mask that was required to reach 90% correct responses. This procedure has the advantage of taking into account the real processing time and excluding the time for the generation of the motor response. Twelve congenitally deaf adult subjects and twelve normal subjects were given a visual search task for a target letter O among a varying number of distractor letters Q and vice-versa. In both groups we found the asymmetrical visual search pattern classically observed with parallel processing for the search for the target Q and with serial processing for the search for the target O (Treisman, 1985 Computer Vision, Graphics, and Image Processing31 156 – 177). The difference between the mean search slopes for an O target was not statistically significant between the groups; this might be due to the variability within the groups. The visual search amidst the congenitally deaf does not seem to benefit from a compensatory effect in relation to the acoustic deprivation. Our results seem to confirm data reported by Neville (1990 Annals of the New York Academy of Science 71 – 91) obtained by an electrophysiological technique based on event-related potentials. Nevertheless, the deaf subjects were 2.5 times faster at the visual search task.

scholarly journals Effects of Attention on Neuroelectric Correlates of Auditory Stream Segregation

2006 ◽  
Vol 18 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Joel S. Snyder ◽  
Claude Alain ◽  
Terence W. Picton
Keyword(s):  
Right Hemisphere ◽  
Event Related Potentials ◽  
Auditory Scene Analysis ◽  
General Assumption ◽  
Stimulus Onset ◽  
Stream Segregation ◽  
Auditory Stream ◽  
Auditory Stream Segregation ◽  
Auditory Evoked Response ◽  
Related Potentials

A general assumption underlying auditory scene analysis is that the initial grouping of acoustic elements is independent of attention. The effects of attention on auditory stream segregation were investigated by recording event-related potentials (ERPs) while participants either attended to sound stimuli and indicated whether they heard one or two streams or watched a muted movie. The stimuli were pure-tone ABA-patterns that repeated for 10.8 sec with a stimulus onset asynchrony between A and B tones of 100 msec in which the A tone was fixed at 500 Hz, the B tone could be 500, 625, 750, or 1000 Hz, and was a silence. In both listening conditions, an enhancement of the auditory-evoked response (P1-N1-P2 and N1c) to the B tone varied with f and correlated with perception of streaming. The ERP from 150 to 250 msec after the beginning of the repeating ABA-patterns became more positive during the course of the trial and was diminished when participants ignored the tones, consistent with behavioral studies indicating that streaming takes several seconds to build up. The N1c enhancement and the buildup over time were larger at right than left temporal electrodes, suggesting a right-hemisphere dominance for stream segregation. Sources in Heschl's gyrus accounted for the ERP modulations related to f-based segregation and buildup. These findings provide evidence for two cortical mechanisms of streaming: automatic segregation of sounds and attention-dependent buildup process that integrates successive tones within streams over several seconds.

Activation of Preexisting and Acquired Face Representations: The N250 Event-related Potential as an Index of Face Familiarity

2006 ◽  
Vol 18 (9) ◽  
pp. 1488-1497 ◽  
Author(s):  
James W. Tanaka ◽  
Tim Curran ◽  
Albert L. Porterfield ◽  
Daniel Collins
Keyword(s):  
Time Course ◽  
Event Related Potentials ◽  
Stimulus Onset ◽  
Event Related Potential ◽  
Same Sex ◽  
Face Representation ◽  
Learning Conditions ◽  
Electrophysiological Studies ◽  
Related Potentials ◽  
Face Stimuli

Electrophysiological studies using event-related potentials have demonstrated that face stimuli elicit a greater negative brain potential in right posterior recording sites 170 msec after stimulus onset (N170) relative to nonface stimuli. Results from repetition priming paradigms have shown that repeated exposures of familiar faces elicit a larger negative brainwave (N250r) at inferior temporal sites compared to repetitions of unfamiliar faces. However, less is known about the time course and learning conditions under which the N250 face representation is acquired. In the familiarization phase of the Joe/no Joe task, subjects studied a target “Joe” face (“Jane” for female subjects) and, during the course of the experiment, identified a series of sequentially presented faces as either Joe or not Joe. The critical stimulus conditions included the subject's own face, a same-sex Joe ( Jane) face and a same-sex “other” face. The main finding was that the subject's own face produced a focal negative deflection (N250) in posterior channels relative to nontarget faces. The task-relevant Joe target face was not differentiated from other nontarget faces in the first half of the experiment. However, in the second half, the Joe face produced an N250 response that was similar in magnitude to the own face. These findings suggest that the N250 indexes two types of face memories: a preexperimentally familiar face representation (i.e., the “own face” and a newly acquired face representation (i.e., the Joe/Jane face) that was formed during the course of the experiment.

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