The effect of binaural beat stimulation on sustained attention.

Binaural beats have been used as a way of modifying cognition via auditory stimulation. A recent meta-analysis suggests that binaural beat stimulation can have a positive effect on attention (Garcia-Argibay et al., Psychologische Forschung 83:1124-1136, 2019a, Psychological Research Psychologische Forschung 83:357-372, 2019b), with the sample-weighted average effect size being about .58. This is an intriguing and potentially useful finding, both theoretically and practically. In this study, we focus on sustained attention. We delivered beta-frequency (16 Hz) binaural beat stimulation during a sustained attention task. In "Experiment 1", reaction times were faster under beat stimulation than control stimulation in a between-subjects design. However, the effect was modest in magnitude, and model comparisons using Bayes Factors were indiscriminate between including and excluding the effect from the model. We followed this initial experiment with two concurrently administered follow-up experiments. In "Experiment 2", we added thought probes to measure any changes in task engagement associated with binaural beat stimulation. "Experiment 2" revealed a different effect from "Experiment 1": participants in the binaural beat condition exhibited a shallower vigilance decrement. However, the beat stimulation did not affect the thought probes responses. Combining data across the two experiments indicated rather strong evidence against the hypothesis that beta-frequency binaural beats can augment sustained attention, either via a general speeding of responding or a mitigation of the vigilance decrement. Finally, in "Experiment 3", we investigated whether pupillary measures of arousal and/or task engagement would be affected by binaural beat stimulation. There was no evidence for such effects. Overall, we did not observe any consistent evidence that binaural beat stimulation can augment sustained attention or its subjective and physiological correlates.

Neural correlates underlying the effect of reward value on recognition memory.

The prioritized encoding and retrieval of valuable information is an essential aspect of human memory. We used electroencephalography (EEG) to determine which of two hypothesized processes underlies the influence of reward value on episodic memory. One hypothesis is that value engages prefrontal executive control processes, so that valuable stimuli engage an elaborative rehearsal strategy that benefits memory. A second hypothesis is that value acts through the reward-related midbrain dopamine system to modulate synaptic plasticity in hippocampal and cortical efferents, thereby benefiting memory encoding. We used a value-directed recognition memory (VDR) paradigm in which participants encoded words assigned different point values and aimed to maximize the point value of subsequently recognized words. Subjective states of recollection (i.e., "remember") and familiarity (i.e., "know") were assessed at retrieval. Words assigned higher values at study were recognized more effectively than words assigned lower values, due to increased "remember" responses but no difference in "know" responses. Greater value was also associated with larger amplitudes of an EEG component at retrieval that indexes recollection (parietal old/new component), but had no relationship with a component that indexes familiarity (FN400 component). During encoding, we assessed a late frontal positivity (frontal slow wave, FSW) that has been related to elaborative rehearsal strategies and an early parietal component (P3) thought to index dopamine driven attention allocation. Our findings indicate that the effect of value on recognition memory is primarily driven by the dopamine-driven reward valuation system (P3) with no discernible effect on rehearsal processes (FSW).

Deep Neural Network for Visual Stimulus-Based Reaction Time Estimation Using the Periodogram of Single-Trial EEG.

Multiplexed deep neural networks (DNN) have engendered high-performance predictive models gaining popularity for decoding brain waves, extensively collected in the form of electroencephalogram (EEG) signals. In this paper, to the best of our knowledge, we introduce a first-ever DNN-based generalized approach to estimate reaction time (RT) using the periodogram representation of single-trial EEG in a visual stimulus-response experiment with 48 participants. We have designed a Fully Connected Neural Network (FCNN) and a Convolutional Neural Network (CNN) to predict and classify RTs for each trial. Though deep neural networks are widely known for classification applications, cascading FCNN/CNN with the Random Forest model, we designed a robust regression-based estimator to predict RT. With the FCNN model, the accuracies obtained for binary and 3-class classification were 93% and 76%, respectively, which further improved with the use of CNN (94% and 78%, respectively). The regression-based approach predicted RTs with correlation coefficients (CC) of 0.78 and 0.80 for FCNN and CNN, respectively. Investigating further, we found that the left central as well as parietal and occipital lobes were crucial for predicting RT, with significant activities in the theta and alpha frequency bands.

Acute pain disrupts prospective memory cue detection processes.

Prospective memory refers to the planning, retention, retrieval, and execution of intentions for future behaviours and it is integral to the enterprise of daily living. Although prospective memory relies upon retrospective memory and executive processes often disrupted by pain, limited research has explored the influence of acute or chronic pain on the ability to complete prospective memory tasks. In the present study we investigated the influence of acute pain on prospective memory tasks that varied in their demands on executive processes (i.e., non-focal versus focal prospective memory cues). Complex-span working memory tasks were also administered to examine whether individual differences in working memory capacity moderated any negative impact of pain on prospective memory. Acute pain significantly impaired prospective memory performance in conditions that encouraged non-focal strategic processing of prospective memory cues, but not in conditions that encouraged more spontaneous focal processing. Individual differences in working memory capacity did not moderate the effect of acute pain on non-focal prospective memory. These findings provide new insights into prospective memory dysfunction created by painful experiences.

ERP Evidence for Implicit Priming of Top-Down Control of Attention.

Proportion congruency effects are the observation that the magnitude of the Stroop effect increases as the proportion of congruent trials in a block increases. Contemporary work shows that proportion effects can be specific to a particular context. For example, in a Simon task in which items appearing above fixation are mostly congruent and items appearing below fixation are mostly incongruent, the Simon effect is larger for the items appearing at the top. There is disagreement as to whether these context-specific effects result from simple associative learning or, instead, a type of conflict-mediated associative learning. Here, we address this question in an ERP study using a Simon task in which the proportion congruency effect was context-specific, manipulating the proportion of congruent trials based on location (upper vs. lower visual field). We found significant behavioral proportion congruency effects that varied with the specific contexts. In addition, we observed that the N2 response of the ERPs to the stimuli was larger in amplitude for the high congruent (high conflict) versus low congruent (low conflict) conditions/contexts. Because the N2 is known to be greater in amplitude also for trials where conflict is high and is believed to be an electrical signal related to conflict detection in the medial frontal cortex, this supports the idea that conflict-mediated associative learning is involved in the proportion congruency effect.

Learning to Listen: Changes in Children's Brain Activity Following a Listening Comprehension Intervention.

"Are you LISTENING?" may be one of the most frequent questions preschoolers hear from their parents and teachers, but can children be taught to listen carefully-and thus better comprehend language-and if so, what changes occur in their brains? Twenty-seven four- and five-year-old children were taught a language simulation strategy to use while listening to stories: first, they practiced moving graphics on an iPad to correspond to the story actions, and then they practiced imagining the movements. Compared to a control condition, children in the intervention answered comprehension questions more accurately when imagining moving the graphics and on a measure of transfer using a new story without any instruction and with only immovable graphics. Importantly, for children in the intervention, the change in comprehension from the first to the sixth day was strongly correlated with changes in EEG mu and alpha desynchronization, suggesting changes in motor and visual processing following the intervention. Thus, the data are consistent with our hypothesis that a language simulation listening comprehension intervention can improve children's listening comprehension by teaching children to align visual and motor processing with language comprehension.

An assessment of learning rates in habitual prospective memory.

Most laboratory research in the field of prospective memory has focused on newly formed (episodic) intentions that are carried out in the experimental context once or only a small number of times. However, many naturalistic prospective memories are carried out many times and these types of (habitual) intentions have been studied much less in the laboratory. In the current study, our aim was to extend prior work examining habitual intentions in laboratory prospective memory paradigms. Participants formed a typical prospective memory intention and then completed an ongoing task in which the intention could be executed up to 63 times. We examined changes in performance across trials in three traditionally important prospective memory metrics: cue detection, task interference, and cue interference. Across repeated performance of the prospective memory task, we observed an increase in cue detection, elimination of task interference, and elimination of cue interference. These results provide key insights into the operation of learning mechanisms in prospective memory paradigms and promote theory development by showing that many of the resource-demanding processes that are theorized to be necessary for successful prospective memory play much less of a role when intentions are repeatedly completed.

3D CNN to Estimate Reaction Time from Multi-Channel EEG.

The study of human reaction time (RT) is invaluable not only to understand the sensory-motor functions but also to translate brain signals into machine comprehensible commands that can facilitate augmentative and alternative communication using brain-computer interfaces (BCI). Recent developments in sensor technologies, hardware computational capabilities, and neural network models have significantly helped advance biomedical signal processing research. This study is an attempt to utilize state-of-the-art resources to explore the relationship between human behavioral responses during perceptual decision-making and corresponding brain signals in the form of electroencephalograms (EEG). In this paper, a generalized 3D convolutional neural network (CNN) architecture is introduced to estimate RT for a simple visual task using single-trial multi-channel EEG. Earlier comparable studies have also employed a number of machine learning and deep learning-based models, but none of them considered inter-channel relationships while estimating RT. On the contrary, the use of 3D convolutional layers enabled us to consider the spatial relationship among adjacent channels while simultaneously utilizing spectral information from individual channels. Our model can predict RT with a root mean square error of 91.5 ms and a correlation coefficient of 0.83. These results surpass all the previous results attained from different studies.Clinical relevance Novel approaches to decode brain signals can facilitate research on brain-computer interfaces (BCIs), psychology, and neuroscience, enabling people to utilize assistive devices by root-causing psychological or neuromuscular disorders.

Behavioral and neural evidence for item-specific performance monitoring.

How cognitive control is recruited and implemented has become a major focus of researchers in cognitive psychology and neuroscience. Current theories posit that cognitive control operates at the level of general rules--for example, in a Stroop task, "attend to the color of the stimulus." Here we report behavioral evidence suggesting that cognitive control is implemented much more locally, operating at the level of specific stimuli appearing in a task block. In addition, we report neural evidence that many of the regions implicated in cognitive control on the Stroop task, including anterior cingulate cortex and dorsolateral prefrontal cortex, operate at a local level.

Reliability and Convergence of Conflict Effects.

Recent work in attentional control has suggested that conflict effects measured across different tasks are not reliable and by extension unrelated. The lack of correlation between these conflict effects is in juxtaposition not only to theoretical predictions of a domain-general attentional control mechanism but also to a large body of individual differences research that has used these tasks to show evidence for an attentional control construct and its relatedness to other psychological constructs. In an effort to address this, we fit hierarchical models to each task that modeled trial-to-trial variability in response times to assess the extent to which the parameter estimates for the conflict effect correlated across tasks. We compared this method of assessing shared variance to more traditional summed difference score estimates of the conflict effect by analyzing data from a large-scale individual differences experiment, in which N = 582 subjects completed a Stroop, Flanker, and Simon task. Across tasks, we found that while the reliability of the conflict was sufficiently high and the between-task conflict effect significantly correlated, the magnitude of the between-task correlation was low. We discuss the implications of these results as providing more support for a domain-specific than domain-general attentional control mechanism.

A Generalized Model to Estimate Reaction Time Corresponding to Visual Stimulus Using Single-Trial EEG.

The estimation of the visual stimulus-based reaction time (RT) using subtle and complex information from the brain signals is still a challenge, as the behavioral response during perceptual decision making varies inordinately across trials. Several investigations have tried to formulate the estimation based on electroencephalogram (EEG) signals. However, these studies are subject-specific and limited to regression-based analysis. In this paper, for the first time to our knowledge, a generalized model is introduced to estimate RT using single-trial EEG features for a simple visual reaction task, considering both regression and classification-based approaches. With the regression-based approach, we could predict RT with a root mean square error of 111.2 ms and a correlation coefficient of 0.74. A binary and a 3-class classifier model were trained, based on the magnitude of RT, for the classification approach. Accuracy of 79% and 72% were achieved for the binary and the 3-class classification, respectively. Limiting our study to only high and low RT groups, the model classified the two groups with an accuracy of 95%. Relevant EEG channels were evaluated to localize the part of the brain significantly responsible for RT estimation, followed by the isolation of important features.Clinical relevance- Electroencephalogram (EEG) signals can be used in Brain-computer interfaces (BCIs), enabling people with neuromuscular disorders like brainstem stroke, amyotrophic lateral sclerosis, and spinal cord injury to communicate with assistive devices. However, advancements regarding EEG signal analysis and interpretation are far from adequate, and this study is a step forward.

Children's mu suppression is sensitive to witnessing others' social victimization.

Empathy has been a key focus of social, developmental, and affective neuroscience for some time. However, research using neural measures to study empathy in response to social victimization is sparse, particularly for young children. In the present study, 58 children's (White, non-Hispanic; five to nine years old) mu suppression was measured using electroencephalogram methods (EEG) as they viewed video scenarios depicting social injustices toward White and Black children. We found evidence of increased mu suppression in response to social victimization; however, contrary to well-documented findings of ingroup racial bias in empathic responses among adults, we found no evidence of racial bias in mu suppression in young children. Implications of these findings for neuroscience research on empathy and the development of ingroup bias are discussed.

Are cognitive control processes reliable?

Recent work on cognitive control focuses on the conflict-monitoring hypothesis, which posits that a performance monitoring mechanism recruits regions in the dorsolateral prefrontal cortex to ensure that goal-directed behavior is optimal. Critical to this theory is that a single performance monitoring mechanism explains a large number of behavioral effects including the sequential congruency effect (SCE) and the error-related slowing (ERS) effect. This leads to the prediction that the size of these effects should correlate across cognitive control tasks. To this end, we conducted three large-scale individual differences experiments to examine whether the SCE and ERS effect are correlated across Simon, Flanker, and Stroop tasks. Across all experiments, the results revealed a correlation for the error-related slowing effect, but not for the sequential congruency effect across tasks. We discuss the implications of these results in regards to the hypothesis that a domain-general performance monitoring mechanism drives both effects. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Alpha suppression over parietal electrode sites predicts decisions to trust.

Decisions to trust help form the basis of relationships and society yet little is known about their neurophysiology. We told participants they were playing a coin toss game with a trustworthy and an untrustworthy person and measured their neural activity with EEG as they decided whether to trust those fictitious interaction partners. Target people ostensibly correctly reported the outcome of a coin toss on 66% of trials. Behaviorally, participants probability matched and chose to trust the reported coin flips from each profile equally by the end of 100 trials. Electrophysiologically, there were reliable differences in the pattern of oscillatory activity in the alpha band (8-13Hz) over parietal electrode sites 1-3 s prior to their trust decisions. Specifically, for trustworthy profiles, there was greater alpha suppression for trust decisions vs. distrust decisions. Conversely, for untrustworthy profiles there was greater alpha suppression for distrust decisions vs. trust decisions. This differential activity (trust minus distrust) also predicted the number of trust decisions made. Our results indicate that the intentions to trust people form very early in the processing stream and manifest as alpha suppression over parietal cortex.

Nonstrategic contributions to putatively strategic effects in selective attention tasks.

Proportion compatible manipulations are often used to index strategic processes in selective attention tasks. Here, a subtle confound in proportion compatible manipulations is considered. Specifically, as the proportion of compatible trials increases, the ratio of complete repetitions and complete alternations to partial repetitions increases on compatible trials but decreases on incompatible trials. This confound is demonstrated to lead to an overestimation in the magnitude of the proportion compatible effect in the context of both a Stroop and a Simon task. Implications for previous research and directions for future research using proportion compatible manipulations are discussed.

Covert orienting: a compound-cue account of the proportion cued effect.

An increase in the proportion of spatially cued trials in the context of the covert orienting paradigm increases the magnitude of the cuing effect. This proportion cued effect is widely interpreted to reflect a form of control. Specifically, it is argued that participants strategically allocate attention as a function of the utility of the spatial cue. Here, an alternative explanation of the proportion cued effect is proposed that does not require control. According to this account, the cue-target event forms a compound cue and the proportion cued manipulation produces a relative disparity in the frequency with which particular compound cues occur. Specifically, when the proportion of spatially cued trials is increased, the frequency of spatially cued cue-target events increases and the frequency of spatially miscued cue-target events decreases, thus increasing the magnitude of the cuing effect. The results of two experiments support this account.

Contingency learning is reduced for high conflict stimuli.

Recent theories have proposed that contingency learning occurs independent of control processes. These parallel processing accounts propose that behavioral effects originally thought to be products of control processes are in fact products solely of contingency learning. This view runs contrary to conflict-mediated Hebbian-learning models that posit control and contingency learning are parts of an interactive system. In this study we replicate the contingency learning effect and modify it to further test the veracity of the parallel processing accounts in comparison to conflict-mediated Hebbian-learning models. This is accomplished by manipulating conflict to test for an interaction, or lack thereof, between conflict and contingency learning. The results are consistent with conflict-mediated Hebbian-learning in that the addition of conflict reduces the magnitude of the contingency learning effect.

Working memory cannot regulate overt emotional capture.

Individual differences in working memory capacity partly arise from variability in attention control, a process influenced by negative emotional content. Thus, individual differences in working memory capacity should predict differences in the ability to regulate attention in emotional contexts. To address this hypothesis, a complex-span working memory task was modified so that negative arousing images or neutral images subtended the background during the encoding phase. Across three experiments, negative arousing images impaired working memory encoding relative to neutral images, resulting in impoverished symmetry span scores. Contrary to the primary hypothesis, individual differences in working memory capacity derived from three complex span tasks failed to moderate the effect of negative arousing images on working memory encoding across two large scale studies. Additionally, in Experiment 3, both negative and arousing images captured attention and were processed despite their incongruence with task goals which led to increased memory for the images in a subsequent recognition task. Implications for theories of working memory and attention control in emotional contexts will be discussed.

Structural neural predictors of Farsi-English bilingualism.

The neurobiology of bilingualism is hotly debated. The present study examines whether normalized cortical measurements can be used to reliably classify monolinguals versus bilinguals in a structural MRI dataset of Farsi-English bilinguals and English monolinguals. A decision tree classifier classified bilinguals with an average correct classification rate of 85%, and monolinguals with a rate of 71.4%. The most relevant regions for classification were the right supramarginal gyrus, left inferior temporal gyrus and left inferior frontal gyrus. Larger studies with carefully matched monolingual and bilingual samples are needed to confirm that features of these regions can reliably categorize monolingual and bilingual brains. Nonetheless, the present findings suggest that a single structural MRI scan, analyzed with measures readily available using default procedures in a free open-access software (Freesurfer), can be used to reliably predict an individual's language experience using a decision tree classifier, and that Farsi-English bilingualism implicates regions identified in previous group-level studies of bilingualism in other languages.

Item-specific adaptation and the conflict-monitoring hypothesis: a computational model.

M. M. Botvinick, T. S. Braver, D. M. Barch, C. S. Carter, and J. D. Cohen (2001) implemented their conflict-monitoring hypothesis of cognitive control in a series of computational models. The authors of the current article first demonstrate that M. M. Botvinick et al.'s (2001) conflict-monitoring Stroop model fails to simulate L. L. Jacoby, D. S. Lindsay, and S. Hessels's (2003) report of an item-specific proportion-congruent (ISPC) effect in the Stroop task. The authors then implement a variant of M. M. Botvinick et al.'s model based on the assumption that control must be able to operate at the item level. This model successfully simulates the ISPC effect. In addition, the model provides an alternative to M. M. Botvinick et al.'s explanation of the list-level proportion-congruent effect in terms of an ISPC effect. Implications of the present modeling effort are discussed.