The effects of mindfulness on body awareness and interoception have been proposed as potential mechanisms for its salwould be accompanied by neural correlates of increased alpha modulation over the somatosensory cortex as measured through EEG. Participants were asked to detect a near-threshold tactile sensation, which was combined with a non-informative light in 50% of the cases. Associations between prestimulus alpha activity and responses were analysed on a trial-by-trial basis. Contrary to our expectation, instead of an increase in accuracy, we observed a decrease in the decision threshold in meditators, while we found a decrease in prestimulus alpha power in meditators. A trial-by-trial analysis revealed a negative relationship between prestimulus alpha activity and the report of touch. Meditators self-reported higher interoceptive abilities compared to readers. These findings suggest that lower prestimulus alpha activity may have increased the probability of reporting touch within the SSDT, providing a potential mechanism for the increase in response rate in meditators. Our study indicates that meditation practice alters body awareness as shown by modulated prestimulus alpha activity, potentially decreasing the filter function over the somatosensory cortex.

Transcranial direct current stimulation (tDCS) of the prefrontal cortex (PFC) modulates the autonomic nervous system by activating deeper brain areas via top-down pathway. However, effects on the nervous system are heterogeneous and may depend on the amount of current that penetrates the brain due to individual brain anatomical differences. Therefore, investigated the variable effects of tDCS on heart rate variability (HRV), a measure of the functional state of the autonomic nervous system. Using three prefrontal tDCS protocols (1.5mA, 3mA and sham), we associated the simulated individual electric field (E-field) magnitude in brain regions of interest with the HRV effects. This was a randomized, double-blinded, sham-controlled and within-subject trial, in which participants received tDCS sessions separated by two weeks. The brain regions of interest were the dorsolateral PFC (DLPFC), anterior cingulate cortex, insula and amygdala. Overall, 37 participants (mean age = 24.3 years, standard deviation = 4.8) were investigated, corresponding to a total of 111 tDCS sessions. The findings suggested that HRV, measured by Root Mean Squared of Successive Differences (RMSSD) and high-frequency HRV (HF-HRV), were significantly increased by the 3.0mA tDCS when compared to sham and 1.5mA. No difference was found between sham and 1.5mA. E-field analysis showed that all brain regions of interest were associated with the HRV outcomes. However, this significance was associated with the protocol intensity, rather than inter-individual anatomical variability. To conclude, our results suggest a dose-dependent effect of tDCS for HRV. Therefore, further research is warranted to investigate the optimal current dose to HRV.

Understanding the subprocesses of risky decision-making is prerequisite for understanding (dys-)functional decisions. For the present fMRI study we designed a variant of the balloon-analogue-risk task (BART) that allows separating decision making from reward anticipation and feedback processing. 29 healthy young adults completed the BART. We analyzed neural activity and functional connectivity. Parametric modulation allowed assessing changes in brain functioning depending on the riskiness of the decision. Our results confirm involvement of Nacc, Insula, ACC and DLPFC in all subprocesses of risky decision making. In addition, subprocesses were differentiated by the strength of activation in these regions, as well as by changes in activity and Nacc-connectivity by the riskiness of the decision. The presented fMRI-BART variant allows distinguishing activity and connectivity during the subprocesses of risky decision making and shows how activation and connectivity patterns relate to the riskiness of the decision. Hence, it is a useful tool for unraveling impairments in subprocesses of risky decision making in people with high risk behavior.

Predictive coding framework posits that our brain continuously monitors changes in the environment and updates its predictive models, minimizing prediction errors to efficiently adapt to environmental demands. However, the underlying neurophysiological mechanisms of these predictive phenomena remain unclear. The present study aimed to explore the systemic neurophysiological correlates of predictive coding processes during passive and active auditory processing. Electroencephalography (EEG), functional near-infrared spectroscopy (fNIRS) and autonomic nervous system (ANS) measures were analyzed using an auditory pattern-based novelty oddball paradigm. A sample of thirty-two healthy subjects was recruited. The results showed shared slow evoked potentials between passive and active conditions that could be interpreted as automatic predictive processes of anticipation and updating, independent of conscious attentional effort. A dissociated topography of the cortical hemodynamic activity and distinctive evoked potentials upon auditory pattern violation were also found between both conditions, whereas only conscious perception leading to imperative responses was accompanied by phasic ANS responses. These results suggest a systemic-level hierarchical reallocation of predictive coding neural resources as a function of contextual demands in the face of sensory stimulation. Principal component analysis permitted to associate the variability of some of the recorded signals.

Unselfishness is one of the admired facilitators for human group endeavors, especially in times of urgent calls for global collaboration. Despite its importance, the neural dynamics behind its formation is scarcely understood. With 26 triads interacting as turn-taking pairs in a coordination game, we investigated reciprocal interactions in this tri-fMRI hyperscanning experiment. The critical role of the right temporal-parietal junction (rTPJ) was examined by adopting both time- and frequency-domain analyses. For the former, in the successful versus failed “reciprocity” contrast, brain regions associated with the mirror neuron system (MNS) and the mentalizing system (MS) were identified. In addition, the differences of connectivity between the rTPJ (seed region) and the abovementioned network areas (e.g., the right Inferior Parietal Lobule, rIPL) were negatively correlated with the individual reward. These results both verified the experimental design, which favored ‘reciprocal’ participants/triads with larger gains, and supported the opposition of rTPJ (other-) vs. rIPL (self-concerned) areas during successful social exchanges. Furthermore, the cerebral synchronization of the rTPJs emerged between the interacting pairs, and the coupling between the rTPJ and the right Superior Temporal Gyrus (rSTG) was found between those interacting simultaneously with others of the same group. These coherence findings not only echoed our previous findings, but also reinforced the hypotheses of the rTPJ-rTPJ coupling underpinning simultaneous collaboration and the rTPJ-rSTG coupling for decontextualized shared meaning emergence. Taken together, these results support two of the multi-functions (other-concerning and decontextualizing) subserved by the rTPJ, and highlight its interaction with other self-concerning brain areas in reaching co-benefits.

The neural circuits of reward processing and interval timing (including perception and production) are functionally intertwined, suggesting that it might be possible for momentary reward processing to influence subsequent timing behavior. Previous animal and human studies have mainly focused on the effect of reward on interval perception, whereas its impact on interval production is less clear. In this study, we examined whether feedback, as an example of performance-contingent reward, biases interval production. We recorded EEG from 20 participants while they engaged in a continuous drumming task with different realistic tempos (1728 trials per participant). Participants received color-coded feedback after each beat about whether they were correct (on time) or incorrect (early or late). Regression-based EEG analysis was used to unmix the rapid occurrence of a feedback response called the reward positivity (RewP), which is traditionally observed in more slow-paced tasks. Using linear mixed modelling, we found that RewP amplitude predicted timing behavior for the upcoming beat. This performance-biasing effect of the RewP was interpreted as reflecting the impact of fluctuations in dopaminergic activities on timing, and the necessity of continuous paradigms to make such observations was highlighted.

Vagally-mediated heart rate variability (vmHRV) at resting-state has been associated to cognitive functions dependent on cognitive control, such as memory. However, little is known about the phasic interaction between cognitive and autonomic control. In a pre-registered within-between-subject designed experiment, the potential of vmHRV biofeedback to simultaneously stimulate vmHRV during memory processing and cognitive control over memory was tested, along with investigating psychophysiological association. 71 young healthy adults completed (twice) a false memory task in virtual reality. Immediately before memory encoding and retrieval, participants practiced either vmHRV biofeedback or a control breathing exercise. Cognitive control over memory was assessed as the confidence towards false memories and the capability to discriminate them from true memories. Resting-state vmHRV before each test and phasic vmHRV during memory encoding and retrieval was measured as the root mean square differences (RMSSD) in heart period. vmHRV biofeedback had neither an immediate effect on cognitive control over memory nor on phasic RMSSD. Both metrics were associated only under consideration of the resting-state and heart rate values. Cognitive control over memory was positively predicted by parallel reactivity (i.e., change from baseline) in heart rate (ß = .333) and RMSSD (ß = .238) at memory retrieval. In consistence with previous psychophysiological models, the findings demonstrate a link between cognitive and phasic vagally-mediated autonomic control which extends to higher-level cognitive functions such as long-term memory. In this context, memory performance seems to be dependent on tonic and phasic (frequency) components of parasympathetic modulation in response to memory processing.

Preadolescence is a critical period for the onset of puberty and eating-related psycho-pathology. More advanced pubertal status is associated with elevated eating pathology. However, it was unclear whether this association was moderated by self-referential processing, an important, modifiable cognitive risk for various forms of psychopathology, including eating problems. Fur-ther, no study has examined the neural correlates of self-referential processing in relation to eating pathology. To address these gaps, we examined how the association between pubertal status and disordered eating was moderated by self-referential processing in a community sample of 115 nine-to-12-year-old preadolescents (66 girls; Mean age/SD =10.98/1.18 years; 87.5% White). Youths reported their pubertal status and disordered eating behaviors and completed an ERP ver-sion of the Self-Referent Encoding Task (SRET) to assess self-referential processing. A Principal Component Analysis of the ERP data identified an anterior late positive potential (LPP) in both the positive and negative SRET conditions. The LPP in the positive condition moderated the positive association between pubertal status and disordered eating behaviors, such that this association was significant for youths with a smaller LPP toward positive self-referential cues, but non-significant for those showing a larger LPP toward positive self-referential cues. These results suggest that a deeper processing of positive self-referential information, indicated by a potentiated LPP, may weaken the negative impact of pubertal status on disordered eating. Our findings also suggest that enhancing positive self-referential processing may be a useful tool in preventing the development of eating pathology in preadolescents, especially for those with more advanced pubertal status.

Videogaming, including violent video gaming, has become very common and lockdown measures of the COVID-19 pandemic even increased the prevalence rates. In this study we examined if violent videogaming is associated with more adverse childhood experiences and if it impairs pain processing and fear conditioning. We tested three groups of participants (violent video gamers, nonviolent video gamers, and non-gamers) and examined fear conditioning as well as pain perception during functional magnetic resonance imaging (fMRI). Violent video gamers displayed significantly higher pain thresholds as well as pain tolerance for electric stimulation, pressure pain stimulation, and cold pressor pain measurements compared to nonviolent video gamers and non-gamers. This relationship was moderated by adverse childhood experiences, especially physical neglect. Brain images acquired during the fear conditioning fMRI task showed that violent video gamers display significantly less differential brain activation to stimuli signaling pain versus no pain in the anterior cingulate cortex, the juxtapositional lobule cortex, and the paracingulate gyrus compared to non-gamers. There was also a significant negative correlation between adverse childhood experiences and activation in the precuneus and the intracalcarine cortex for signals of pain versus safety. The results of this study imply that violent video gaming is related to reduced processing of pain and signals of pain in a fear learning task, dependent of adverse childhood experiences. These mechanisms need to be examined in more detail and these data could be helpful in preventing the onset and adverse consequences of violent video gaming.

In recent years, steady state visual evoked potentials (SSVEPs) became an increasingly valuable tool to investigate neural dynamics of competitive attentional interactions and brain computer interfaces. This is due to their good signal-to-noise ratio, allowing for single trial analysis and their ongoing oscillating nature that enables to analyze temporal dynamics of facilitation and suppression. Given the popularity of SSVEPs, it is surprising that only a few studies looked at the cortical sources of these responses. This is in particular the case when searching for studies that assessed the cortical sources of attentional SSVEP amplitude modulations. To address this issue, we used a typical spatial attention task and recorded neuromagnetic fields (MEG) while presenting frequency-tagged stimuli in the left and right visual field, respectively. Importantly, we controlled for attentional deployment in a baseline period before the shifting cue. Subjects either attended to a central fixation cross or to two peripheral stimuli simultaneously. Results clearly showed that signal sources and attention effects were restricted to early visual cortex: V1, V2, hMT+, precuneus, occipital-parietal and inferior-temporal cortex. When subjects attended to central fixation first, shifting attention to one of the peripheral stimuli resulted in a significant activation increase for the to-be-attended stimulus with no activation decrease for the to-be-ignored stimulus in hMT+ and inferio-temporal cortex, but significant SSVEF decreases from V1 to occipito-parietal cortex. When attention was first deployed to both rings, shifting attention away from one ring basically resulted in a significant activation decrease in all areas for the then to-be-ignored stimulus.

Electronic gambling machines include a suite of design characteristics that may contribute to gambling related harms and require more careful attention of regulators and policymakers. One strategy that has contributed to these concerns is the presentation of “losses disguised as wins” (LDWs), a type of salient losing outcome in which a gambling payout is less than the amount wagered (i.e., a net loss), but is nonetheless accompanied by the celebratory audio-visual stimuli that typically accompanies a genuine win. These events could thereby be mistaken for gains, or otherwise act as a reward signal, reinforcing persistent gambling, despite being a loss. This study aimed to determine whether LDWs evoke a reward positivity component in a task modelled on slot-machine gambling. A prominent account of the reward positivity event-related potential suggests that it is evoked during the positive appraisal of task related feedback, relative to neutral or negative events, or that it is evoked by neural systems that implement the computation of a positive reward prediction error. We recruited 32 individuals from university recruitment pools and asked them to engage in a simple gambling task designed to mimic key features of a slot machine design. The reward positivity was identified using temporospatial principal components analysis. Results indicated a more positive reward positivity following LDWs relative to clear losses, consistent with the theory that LDWs contribute to positive reinforcement of continued gambling, despite being net losses.Now peer-reviewed, updated and published in psychophysiology. Cite as: Myles, D., Carter, A., Yücel, M., & Bode, S. (2024). Losses disguised as wins evoke the reward positivity event-related potential in a simulated machine gambling task. Psychophysiology, 00, e14541. https://doi.org/10.1111/psyp.14541

When memorizing an integrated object such as a Kanizsa figure, the completion of parts into a coherent whole is attained by grouping processes which render a whole-object representation in visual working memory (VWM). The present study measured event-related potentials (ERPs) and oscillatory amplitudes to track these processes of encoding and representing multiple features of an object in VWM. To this end, a change detection task was performed, which required observers to memorize both the orientations and colors of six ‘pacman’ items while inducing configurations of the pacmen that systematically varied in terms of their grouping strength. The results revealed an effect of object configuration in VWM despite physically constant visual input: change detection for both orientation and color features was more accurate with increased grouping strength. At the electrophysiological level, the lateralized ERPs and alpha activity mirrored this behavioral pattern. Perception of the orientation features gave rise to the encoding of a grouped object as reflected by the amplitudes of the PPC. The grouped object structure, in turn, modulated attention to both orientation and color features as indicated by the enhanced N1pc and N2pc. Finally, during item retention, the representation of individual objects and the concurrent allocation of attention to these memorized objects were modulated by grouping, as reflected by variations in the CDA amplitude and a concurrent lateralized alpha suppression, respectively. These results indicate that memorizing multiple features of grouped, to-be-integrated objects involves multiple, sequential stages of processing, providing support for a hierarchical model of object representations in VWM.

A document by Nuno Busch. Click on the document to view its contents.

Recent evidence suggests that the autonomic nervous system can contribute to memory consolidation during sleep. Whether fluctuations in cardiac autonomic activity during sleep following physical exercise contribute to the process of memory consolidation has not been studied. We assessed the effects of a non-rapid eye movement (NREM) nap following acute exercise on cardiac autonomic regulation assessed with heart rate variability (HRV) to examine if HRV influences memory processes. Fifty-six (59% female) healthy young adults (23.14 ± 3.74 years) were randomly allocated to either the exercise plus nap (ExNap, n = 27) or nap alone (NoExNap, n = 29) groups. The ExNap group performed a 40-minute moderate-intensity cycling, while the NoExNap group was sedentary prior to learning 45 neutral pictures for a later test. Subsequently, participants underwent a 60-minute NREM nap while measuring EKG, followed by a visual recognition test. Our results indicated that heart rate did not significantly differ between the groups (p = 0.302); whereas vagally-mediated HRV indices were lower in the ExNap group compared to the NoExNap group (p < 0.05). There were no significant differences in sleep variables (p > 0.05). Recognition accuracy was significantly higher in the ExNap group than in the NoExNap group (p = 0.027). In addition, the recognition accuracy of the ExNap group was negatively associated with vagally-mediated HRV (p < 0.05). Pre-nap acute exercise attenuated parasympathetic activity and appears to alter the relationship between memory and cardiac autonomic activity, suggesting that post-exercise memory enhancement may be based on other mechanisms.

We describe methods and software resources for a bioimpedance measurement technique, “trans-radial electrical bioimpedance velocimetry” that allows for the non-invasive monitoring of relative cardiac contractility and stroke volume, proxies of sympathetic cardiac tone. In addition to describing the general recording methodology, which requires impedance measurements of the forearm, we provide open source Jupyter based software (operable on most computers) for deriving cardiac contractility from the impedance measurements. We demonstrate the ability of this bioimpedance measurement for tracking event related contractility in a maximal grip force production task. Critically, the results demonstrate both a reactive increase in cardiosympathetic drive with force production as well as a learned increase in drive prior to grip onset, consistent with allostatic autonomic regulation. The method and software should be of broad utility for investigations of event related cardio-sympathetic regulation in psychophysical studies.

With the ever-changing social environment, individual creativity is facing a severe challenge induced by stress. However, little is known about the physiological mechanisms by which acute stress affects creative cognitive processing. The current study explored the effects of neuroendocrine response on creativity under stress and its underlying cognitive flexibility mechanisms. The Enzyme-Linked Immuno Sorbent Assay was used to assess salivary cortisol, which acted as a marker of stress-induced activation of the hypothalamic-pituitary-adrenal (HPA) axis. Eye blink rate (EBR) and pupil diameter were measured as respective indicators of dopamine and noradrenaline released by activation of the sympathetic-adrenal medullary (SAM) axis. The Wisconsin Card Task (WCST) measured cognitive flexibility, while the Alternative Uses Task (AUT) and the Remote Association Task (RAT) measured separately divergent and convergent thinking in creativity. Results showed higher cortisol increments following acute stress induction in the stress group compared to the control group. Ocular results showed that the stress manipulation significantly increased EBR and pupil diameter compared to controls, reflecting increased SAM activity. Further analysis revealed that stress-released cortisol impaired the originality component of the AUT by increasing perspective errors of the WCST. Serial mediation analyses showed that both EBR and pupil diameter were also associated with increased perspective errors leading to poor originality on the AUT. These findings confirm that physiological arousal under stress can impair divergent thinking through the regulation of different neuroendocrine pathways, in which the deterioration of flexible switching plays an important mediating role.

Fear overgeneralization and perceived uncertainty about future outcomes have been suggested as risk factors for clinical anxiety. However, little is known regarding how they influence each other. In this study, we investigated whether different levels of threat uncertainty influence fear generalization. Three groups of healthy participants underwent a differential fear conditioning protocol followed by a generalization test. All groups learned to associate one female face (conditioned stimulus, CS+) with a female scream (unconditioned stimulus, US) while the other face (CS-) was not associated with the scream. In order to manipulate threat uncertainty, one group (low uncertainty, n = 26) received 80%, the second group (moderate uncertainty, n = 32) received 60%, and the third group (high uncertainty, n = 30) 40% CS-US contingency. In the generalization test, all groups saw CS+ and CS- again as well as four morphs that varied in similarity with the CS+ in steps of 20%. Subjective (expectancy, valence, and arousal ratings), psychophysiological (skin conductance response, SCR), and visuocortical (steady-state visual evoked potentials, ssVEPs) indices of fear were registered. Participants expected the US in accordance with their reinforcement schedules but displayed stronger skin conductance with more uncertainty. However, acquisition of conditioned fear was not evident in ssVEPs. During the generalization test, we found no effect of threat uncertainty in any of the measured variables, but the strength of generalization for threat expectancy ratings was positively correlated with dispositional intolerance of uncertainty. This study suggests that mere threat uncertainty does not modulate fear generalization.

Active engagement improves learning and memory, and self- vs. externally generated stimuli are processed differently: perceptual intensity and neural responses are attenuated. Whether the attenuation is linked to memory formation remains to be understood. This study investigates whether active oculomotor control over auditory stimuli – controlling for movement and stimulus predictability – benefits associative learning, and studies the underlying neural mechanisms. Using EEG and eyetracking we explored the impact of control during learning on the processing and memory recall of arbitrary oculomotor-auditory associations. Participants (N=23) learned associations through active exploration or passive observation, using a gaze-controlled interface to generate sounds. Our results show faster learning progress in the active condition. ERPs time-locked to the onset of sound stimuli showed that learning progress was linked to an attenuation of the P3a component. The detection of matching movement-sound pairs triggered a target-matching P3b response. There was no general modulation of ERPs through active learning. However, participants could be divided into different learner types: those who benefited strongly from active control during learning and those who did not. The strength of the N1 attenuation effect for self-generated stimuli was correlated with memory gain in active learning. Our results show that control helps learning and memory and modulates sensory responses. Individual differences during sensory processing predict the strength of the memory benefit. Taken together, these results help to disentangle the effects of agency, unspecific motor-based neuromodulation, and stimulus predictability on ERP components and establish a link between self-generation effects and active learning memory gain.