Psychophysiology最新文献

This study addressed a long-standing controversy in the attention and action literature concerning whether speeding of a voluntary reaction by a neutral warning signal (WS) is due to faster, more efficient preparation and execution of the motor response. In contrast to most previous research, we found that manipulation of foreperiod duration (the interval from onset of the WS to onset of the reaction stimulus) did influence hand-specific activity in the sensorimotor cortex, as measured with the lateralized readiness potential (LRP). We also confirmed that when cortical activity contralateral and ipsilateral to the hand of response is separately measured using localized current source density (surface Laplacian waves), speeding of late motoric processes can be observed. Certain alternative possibilities, such as distortion of the baseline-correction procedure by the contingent negative variation (CNV) or misidentification of latency effects due to what we call the "aperture problem," could not fully account for the findings. Facilitation of late motoric processes was most evident when the response involved a sequence of keypresses, comparable to a short phrase on the piano. Relative merits of conventional LRPs versus surface Laplacians are discussed.

Interference from distractors can be reduced when they appear with frequently occurring features, suggesting that statistical learning attenuates distractor interference. Previous research on spatial statistical learning has shown that reduced interference may reflect both suppression of high-probability locations and enhanced capture by low-probability locations. Whether feature-based statistical learning follows the same pattern remains unclear. We ran two experiments combining behavioral and EEG measures. Experiment 1 replicated earlier findings that high-probability distractors interfered less with target search than low-probability distractors. Experiment 2 introduced an equal-probability baseline and recorded ERPs. Behaviorally, response times were faster for high-probability distractors than for both equal- and low-probability distractors, which did not differ from each other. Neurally, distractor-evoked N2pc amplitudes were smaller for high-probability distractors than for equal- and low-probability distractors. Whereas, the P_D component was reliably observed but did not differ across conditions. Target-evoked N2pc amplitudes were likewise unaffected by distractor probability. Taken together, these findings indicate that feature-based statistical learning primarily reduces interference of high-probability distractors, rather than enhancing rarity-driven capture of low-probability distractors, and that these effects are specific to distractor rather than target processing.

Despite the central role of honesty in moral cognition, a critical question remains: what neural patterns underlie our self-favorable judgments when evaluating our own honesty compared to that of others? To investigate this, a behavioral study and a functional Magnetic Resonance Imaging (fMRI) study were conducted. In Study 1 (N = 506), participants evaluated honesty-related traits, moral traits other than honesty, and other traits in relation to themselves or the majority. Results showed that participants believed they possessed more and higher levels of both honest and moral traits compared to the majority, with honesty demonstrating stronger internalized identification. Study 2 (N = 62) employed functional magnetic resonance imaging (fMRI) to examine neural activity during trait evaluation tasks. Significantly stronger medial prefrontal cortex (mPFC) activity was found during self versus majority trait judgments, specifically for other traits. However, participants with stronger internalization of honest identity showed greater mPFC engagement when evaluating whether honest traits described themselves. Further exploratory representational similarity analyses showed that the mPFC differentiates between the three trait categories in a nuanced manner. Together, these findings highlight that honesty plays a central role in self-concept, and the mPFC supports self-referential trait differentiation, with its involvement in honesty-related processing varying across individuals.

There is increasing evidence that the cerebellum contributes to feedback processing in reinforcement learning. As yet, it has not been investigated whether the cerebellum also contributes to error processing in reinforcement learning. Studies have shown, however, that the cerebellum is involved in the processing of response errors in non-reinforcement learning contexts, for example, in response conflict tasks. In the present study, we aimed to extend these findings to the processing of response errors, which slowly emerges as a result of reinforcement learning. To this end, we inhibited the cerebellum via single-pulse transcranial magnetic stimulation (spTMS) and recorded cerebral electroencephalography (EEG) measures associated with error processing. If input from the cerebellum is required for error processing, error-correct differentiation should be decreased for cerebellar compared to vertex (control) stimulation. Cerebellar spTMS was applied and EEG was recorded while healthy adults performed a probabilistic feedback learning task. The error-related negativity (ERN), a component in the response-locked event-related potential (ERP), was used as a measure of error processing. It reflects a rapidly detected mismatch between representations of the actual and the desired response and is typically larger for errors than correct responses. Error-correct differentiation in the ERN was diminished for cerebellar compared to control TMS. However, increased error-correct differentiation was found in a later ERP component, the error positivity (Pe), which is more strongly associated with error awareness. Cerebellar spTMS thus impaired fast error processing reflected in the ERN and facilitated later, conscious error processing reflected in the Pe. These findings provide causal evidence of cerebellar contributions to error processing within reinforcement learning.

Expectancy theory of hypnosis posits that any procedure can serve as a hypnotic induction provided it is labeled as "hypnosis". The present study explored this hypothesis by contrasting the effects of two conventional and two unconventional (placebo) hypnotic inductions on hypnotic experiences and electrophysiological correlates. In a 2 × 2 balanced placebo design, all participants were exposed to four conditions: conventional induction labeled as "hypnosis", conventional induction labeled as "control", unconventional induction labeled as "hypnosis", and unconventional induction labeled as "control". EEG was recorded from 61 channels. We computed EEG features that were identified in previous studies as correlates of hypnosis or hypnotizability. Consistent with the predictions of expectancy theory, we found that labeling of the procedure was most influential in determining subjective hypnosis depth, and one of the unconventional (placebo) inductions, "white noise hypnosis", evoked comparable hypnosis depth to the conventional hypnotic inductions. However, contrary to its predictions, "embedded hypnosis", another unconventional induction, evoked smaller hypnosis depth reports than the other three inductions. Both relaxation and embedded induction procedures showed decreased gamma power in the midline occipital area. Most EEG features we explored were comparable between conventional and unconventional induction conditions, but labeling also seemed to have no effect on EEG changes, which is contrary to the prediction of the expectancy theory. Possible exceptions were a negative effect of conventional induction on functional connectivity between the O1-Pz channels in the theta band, and a decrease in anterior and posterior alpha power in trials labeled "hypnosis". However, these effects were inconclusive. Overall, our results provide only partial support for the expectancy theory of hypnosis. The most promising EEG correlate of hypnosis based on our results is decreased occipital gamma power. However, our findings should be considered exploratory. Confirmatory research is required to strengthen our confidence in these effects. TRIAL REGISTRATION: The research plan of this study was registered on the Open Science Framework (https://osf.io/kugdf) before any data collection. The data collection of the first 9 participants was not in accordance with the research plan due to a programming error. The data from these trials was not used in the confirmatory analysis. Consequently, we made changes to the sampling plan and the analysis plan. The altered version of the research plan had been registered at the Open Science Framework (https://osf.io/wvhda) before any new data was collected.

Previous findings suggest that acute stress enhances attention focused on heartbeats, which is the definition of the construct cardiac "interoceptive attention" (IAt). The difference of heartbeat-evoked potentials (HEPs) assessed while performing a heartbeat counting task (HCT) versus a distraction task is considered an indicator of cardiac IAt. The aim of this study was to investigate whether acute stress enhances cardiac IAt and how activation of the sympatho-adrenomedullary (SAM) and the hypothalamic-pituitary-adrenocortical (HPA) stress axis contributes to this potential effect. Sixty-six young, healthy individuals were randomly assigned to a stress (socially evaluated cold pressor test/SECPT; n = 32) or a control group (n = 34), and underwent a HCT and a distraction task once before and three times (+0, +20, +40 min) after the intervention (SECPT/control). The SECPT effectively increased heart rate, systolic/diastolic blood pressure, and cortisol release. Cardiac interoceptive accuracy based on the HCT was unaffected by stress. Individuals in the SECPT group showed an increase in HEPs (R-wave +455-595 ms) assessed during the HCT 40 min after the intervention (at F8, Cz, C4, CP6, P8). These findings suggest that acute stress may selectively enhance cardiac IAt. Its primarily right-hemispheric topography suggests the involvement of insular activity in mediating this effect. Exploratory analyses in the stress group showed that the responsiveness of HEPs to the stressor (+40 min vs. before) was negatively correlated with stress responsiveness in systolic blood pressure and pain intensity/unpleasantness. Future studies should clarify whether this late effect of acute stress on IAt is due to parasympathetic deactivation during stress recovery, and if their underlying neural networks (e.g., cardiac parasympathetic afferents) play a role in mediating IAt.

The pre-ejection period (PEP) is a widely used cardiac parameter in psychophysiology that reflects the duration between the onset of ventricular depolarization and the opening of the aortic valve. PEP is often used as a marker of cardiac sympathetic nervous system (SNS) activity, particularly in within-subject comparisons under similar hemodynamic conditions. While many algorithms for automated PEP extraction from electrocardiography (ECG) and impedance cardiography (ICG) signals (more precisely, its first derivative, dZ/dt) have been proposed in literature, they have not been systematically benchmarked. This lack of standardized algorithm comparisons originates from the absence of open-source algorithms and annotated datasets for evaluating PEP extraction algorithms. To address this issue, we introduce PEPbench, an open-source Python package with different Q-peak and B-point detection algorithms from literature that can be combined to create comprehensive PEP extraction pipelines, and a standardized framework for evaluating PEP extraction algorithms. We use PEPbench to systematically compare 108 different algorithm combinations. All combinations are evaluated on two datasets with manually annotated Q-peaks and B-points, which we make publicly available as the first datasets with reference PEP annotations. Our results show that the algorithms can differ vastly in their performance and that B-point detection algorithms introduce a considerable amount of error. Thus, we suggest that automated PEP extraction algorithms should be used with caution on a beat-to-beat level as their error rates are relatively high. This highlights the need for open and reproducible benchmarking frameworks for PEP extraction algorithms to improve the quality of research findings in the field of psychophysiology. With PEPbench, we aim to take a first step toward this goal and encourage other researchers to engage in the evaluation of PEP extraction algorithms by contributing algorithms, data, and annotations. We hope to establish a community-driven platform, fostering innovation and collaboration in the field of psychophysiology and beyond.

This study investigates how expectancy and plausibility influence behavioral and neural measures of language processing during naturalistic reading comprehension. Prior event-related potential (ERP) studies show evidence of distinct post-N400 positivities to violations of semantic expectancy and plausibility using artificial serial presentation but have yet to establish these phenomena during naturalistic reading. Therefore, we recorded simultaneous eye movements and EEG while participants read highly constraining sentences with expected, unexpected (but plausible), and anomalous target words. Time locked to the pre-target word, we observed a contextually graded parafoveal N400 effect. The N400 was facilitated (i.e., reduced) when the word was subsequently fixated, suggesting trans-saccadic integration of semantic features. At target fixation, we also observed a late anteriorly distributed positivity to unexpected target words and a posteriorly distributed positivity to anomalous target words, effects that were not clearly present when time locked to the pre-target word. Eye-tracking (ET) measures show that readers were sensitive to both expectancy and plausibility at target fixation. In conclusion, we show that readers can begin accessing semantic information in parafoveal vision, but higher-level semantic processing may require the orchestration of both parafoveal and foveal representations.

The prioritized processing for emotions has been found to modulate the N170, Early Posterior Negativity (EPN), and Late Positive Potential (LPP) within the processing of facial expressions. However, existing evidence on how available attentional resources affect the emotional modulation of these ERP components remains inconsistent. To investigate this issue, we precisely controlled the perceptual load of the first target (T1) in a dual-target rapid serial visual presentation (RSVP) task, aiming to modulate the attentional resources available for processing emotional expressions (happy, fearful, neutral) at the second target (T2). Our results revealed the main effects of emotion in the 180-280 ms and 400-800 ms intervals, which were consistent with the early-stage processing of emotional expressions, as well as the elaborate, late-stage processing. During 320-400 ms, the amplitudes were more negative for high compared to low load conditions, representing a bottleneck in visual processing. The interactions between emotion and perceptual load were observed for the late LPP interval (600-800 ms). Specifically, the processing of happy expressions was modulated by perceptual load levels, whereas fearful expressions exhibited robust prioritized processing even under limited attentional resources. Overall, the present study revealed that the early-stage processing of emotional expressions operates automatically due to their high biological salience. In contrast, late-stage processing relies on the available attentional resources, with fearful expressions requiring minimal attentional resources due to their evolutionary significance.

This study tested the effect of frontal hemispheric asymmetry (FHA) on mental effort in tasks of fixed and unfixed difficulty. To manipulate FHA, we applied high-definition transcranial direct current stimulation (HD-tDCS) to the dorsolateral prefrontal cortex (dlPFC) and assessed its impact on cardiovascular responses. Forty-three participants performed two task conditions: (a) a fixed, easy task with a 50% accuracy criterion for success and (b) an unfixed, self-paced task that delivered monetary rewards for each correct response. Before completing the tasks, participants received left cathodal versus right cathodal stimulation. Prior to each task, participants were told they could earn a moderate monetary incentive. We recorded cardiovascular responses, including pre-ejection period (PEP), systolic blood pressure (SBP), heart rate (HR), and diastolic blood pressure (DBP). We expected right cathodal stimulation to induce left FHA. This should lead to higher effort when task difficulty is unfixed, due to increased participants' approach motivation and success importance. By contrast, no effect of stimulation was expected in the fixed and easy condition. As predicted, PEP reactivity-where more negative values indicate higher effort-was stronger in the unfixed task demand following right cathodal stimulation compared to the left cathodal stimulation and both stimulation conditions when the task was fixed and easy. These findings suggest that neuromodulation of the dlPFC alters effort intensity by shifting FHA, thereby increasing the perceived importance of success, which in turn determines higher effort under unfixed task demands.