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Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.07.30.550770v1?rss=1 Authors: Wong, A. P. H., Wu, E. X. W., Rogers, B. P., Asplund, C. L. Abstract: Functional neuroimaging (fMRI) signals are famously sluggish, unfolding over several seconds after even brief sensory (and neural) events. Relative timing differences between different evoking conditions, however, can distinguish between changes in the duration or intensity of neural activity (Henson et al., 2002). Specifically, increases in stimulus duration cause a delayed response peak with a greater amplitude, whereas increases in stimulus intensity affect the peak magnitude alone. These relationships have been empirically demonstrated using stimulus durations of several seconds (Friston, 2005), but many processes relevant to cognitive psychology occur on sub-second timescales. Here we tested whether the predicted relationship between stimulus properties and the hemodynamic response held for sub-second stimuli and sub-second changes in stimulus duration. In Experiment 1 (n=15), we presented visual and auditory stimuli at three durations (100, 300, and 900 ms) and three intensities in a slow event-related design with a rapid TR (625 ms). In Experiment 2 (n=14), the stimulus durations were extended (1000, 1200, and 1800 ms) to increase the evoked signal. By fitting the observed fMRI signals to parameterised hemodynamic response functions, we found that changes in stimulus duration caused differences in peak latency and magnitude, whereas changes in stimulus intensity affected only peak magnitude. Significant effects were found for duration differences as small as 200 ms, with clearer results when a sufficiently large base signal was evoked and when a bootstrap resampling technique was used. Our results support the validity of existing models of the hemodynamic response. They also support the use of time-resolved fMRI for mental chronometry in cognitive neuroscience, thereby allowing researchers to draw additional inferences about brief mental events. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.04.20.537735v1?rss=1 Authors: Chowdhury, N. S., Chiang, A. K., Millard, S. K., Skippen, P., Chang, W.-J., Seminowicz, D. A., Schabrun, S. M. Abstract: Transcranial magnetic stimulation (TMS) has been used to examine the inhibitory and facilitatory circuits during experimental pain and in chronic pain populations. However, current applications of TMS to pain have been restricted to measurements of motor evoked potentials (MEPs) from peripheral muscles. Here, TMS was combined with electroencephalography (EEG) to determine whether experimental pain could induce alterations in cortical inhibitory/facilitatory activity observed in TMS-evoked potentials (TEPs). In Experiment 1 (n = 29), multiple sustained thermal stimuli were administered over the forearm, with the first, second and third block of stimuli consisting of warm but non-painful (pre-pain block), painful heat (pain block) and warm but non-painful (post-pain block) temperatures respectively. During each stimulus, TMS pulses were delivered while EEG (64 channels) was simultaneously recorded. Verbal pain ratings were collected between TMS pulses. Relative to pre-pain warm stimuli, painful stimuli led to an increase in the amplitude of the frontocentral negative peak ~45ms post-TMS (N45), with a larger increase associated with higher pain ratings. Experiments 2 and 3 (n = 10 in each) showed that the increase in the N45 in response to pain was not due to changes in sensory potentials associated with TMS, or a result of stronger reafferent muscle feedback during pain. This is the first study to use combined TMS-EEG to examine alterations in cortical excitability in response to pain. These results suggest that the N45 TEP peak, which indexes GABAergic neurotransmission, is implicated in pain perception and is a potential marker of individual differences in pain sensitivity. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.04.04.535555v1?rss=1 Authors: Zhao, W. Abstract: Naturalistically, multisensory information of gesture and speech is intrinsically integrated to enable coherent comprehension. Such cross-modal semantic integration is temporally misaligned, with the onset of gesture preceding the relevant speech segment. It has been proposed that gestures prime subsequent speech. However, there are unresolved questions regarding the roles and time courses that the two sources of information play in integration. Here, in two between-subject experiments of healthy college students, we segmented the gesture-speech integration period into 40-ms time windows (TWs) based on two separately division criteria, while interrupting the activity of the integration node of the left posterior middle temporal gyrus (pMTG) and the left inferior frontal gyrus (IFG) with double-pulse transcranial magnetic stimulation (TMS). In Experiment 1, we created fixed time-advances of gesture over speech and divided the TWs from the onset of speech. In Experiment 2, we differentiated the processing stages of gesture and speech and segmented the TWs in reference to the speech lexical identification point (IP), while speech onset occurred at the gesture semantic discrimination point (DP). The results showed a TW-selective interruption of the pMTG and IFG only in Experiment 2, with the pMTG involved in TW1 (-120~-80 ms of speech IP), TW2 (-80~-40 ms), TW6 (80~120 ms) and TW7 (120~160 ms) and the IFG involved in TW3 (-40~0 ms) and TW6. Meanwhile no significant disruption of gesture-speech integration was reported in Experiment 1. We determined that after the representation of gesture has been established, gesture-speech integration occurs such that speech is first primed in a phonological processing stage before gestures are unified with speech to form a coherent meaning. Our findings provide new insights into multisensory speech and co-speech gesture integration by tracking the causal contributions of the two sources of information. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.03.21.533618v1?rss=1 Authors: de Vries, E., van Ede, F. Abstract: Besides controlling eye movements, the brain's oculomotor system has been implicated in the control of covert spatial attention and the rehearsal of spatial information in working memory. We investigated whether the oculomotor system also contributes to rehearsing visual objects in working memory when object location is never asked about. To address this, we tracked the incidental use of locations for mnemonic rehearsal via directional biases in microsaccades while participants maintained two visual objects (coloured oriented gratings) in working memory. By varying the stimulus configuration (horizontal, diagonal, and vertical) at encoding, we could quantify whether microsaccades were more aligned with the configurational axis of the memory contents, as opposed to the orthogonal axis. Experiment 1 revealed that microsaccades continued to be biased along the axis of the memory content several seconds into the working-memory delay. In Experiment 2, we confirmed that this directional microsaccade bias was specific to memory demands, ruling out lingering effects from passive and attentive encoding of the same visual objects in the same configurations. Thus, by studying microsaccade directions, we uncover oculomotor-driven rehearsal of visual objects in working memory through their associated locations. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2023.03.18.533257v1?rss=1 Authors: Beyvers, M., Voudouris, D., Fiehler, K. Abstract: When interacting with objects, we often rely on visual information. However, vision is not always the most reliable sense for determining relevant object properties. For example, when the mass distribution of an object cannot be inferred visually, humans may rely on predictions about the objects dynamics. Such predictions may not only influence motor behavior but also associated somatosensory processing, as sensorimotor predictions lead to reduced tactile sensitivity during movement. We examined whether predictions based on sensorimotor memories influence grasping kinematics and associated tactile processing. Participants lifted an object of unknown mass distribution and reported whether they detected a tactile stimulus on their grasping hand during the lift. In Experiment 1, the mass distribution could change from trial to trial, whereas in Experiment 2, we intermingled longer with shorter parts of constant and variable mass distributions, while also providing implicit or explicit information about the trial structure. In both experiments, participants grasped the object by predictively choosing contact points that would compensate the mass distribution experienced in the previous trial. Tactile suppression during movement, however, was invariant across conditions. These results suggest that predictions based on sensorimotor memories can influence movement kinematics but may not affect associated tactile perception. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2022.11.15.516659v1?rss=1 Authors: Kallmayer, A., Vo, M. L.-H., Draschkow, D. Abstract: Viewpoint effects on object recognition interact with object-scene consistency effects. While recognition of objects seen from "accidental" viewpoints (e.g., a cup from below) is typically impeded compared to processing of objects seen from canonical viewpoints (e.g., the string- side of a guitar), this effect is reduced by meaningful scene context information. In the present study we investigated if these findings established by using photographic images, generalise to 3D models of objects. Using 3D models further allowed us to probe a broad range of viewpoints and empirically establish accidental and canonical viewpoints. In Experiment 1, we presented 3D models of objects from six different viewpoints (0, 60, 120, 180, 240, 300) in colour (1a) and grayscaled (1b) in a sequential matching task. Viewpoint had a significant effect on accuracy and response times. Based on the performance in Experiments 1a and 1b, we determined canonical (0-rotation) and non-canonical (120-rotation) viewpoints for the stimuli. In Experiment 2, participants again performed a sequential matching task, however now the objects were paired with scene backgrounds which could be either consistent (e.g., a cup in the kitchen) or inconsistent (e.g., a guitar in the bathroom) to the object. Viewpoint interacted significantly with scene consistency in that object recognition was less affected by viewpoint when consistent scene information was provided, compared to inconsistent information. Our results show that viewpoint-dependence and scene context effects generalize to depth rotated 3D objects. This supports the important role object-scene processing plays for object constancy. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2022.10.20.513044v1?rss=1 Authors: Kemp, J. T., Cesanek, E., Domini, F. Abstract: The fundamental question of how the brain derives 3D information from the inherently ambiguous visual input has been approached during the last two decades with probabilistic theories of 3D perception. Probabilistic models, such as the Maximum Likelihood Estimation (MLE) model, derive from multiple independent depth cues the most probable 3D interpretations. These estimates are then combined by weighing them according to their uncertainty to obtain the most accurate and least noisy estimate. In three experiments we tested an alternative theory of cue integration termed the Intrinsic Constraint (IC) theory. This theory postulates that the visual system does not derive the most probable interpretation of the visual input, but the most stable interpretation amid variations in viewing conditions. This goal is achieved with the Vector Sum model, that represents individual cue estimates as components of a multidimensional vector whose norm determines the combined output. In contrast with the MLE model, individual cue estimates are not accurate, but linearly related to distal 3D properties through a deterministic mapping. In Experiment 1, we measured the cue-specific biases that arise when viewing single-cue stimuli of various simulated depths and show that the Vector Sum model accurately predicts an increase in perceived depth when the same cues are presented together in a combined-cue stimulus. In Experiment 2, we show how Just Noticeable Differences (JNDs) are accounted for by the IC theory and demonstrate that the Vector Sum model predicts the classic finding of smaller JNDs for combined-cue versus single-cue stimuli. Most importantly, this prediction is made through a radical re-interpretation of the JND, a hallmark measure of stimulus discriminability previously thought to estimate perceptual uncertainty. In Experiment 3, we show that biases found in cue-integration experiments cannot be attributed to flatness cues, as assumed by the MLE model. Instead, we show that flatness cues produce no measurable difference in perceived depth for monocular (3A) or binocular viewing (3B), as predicted by the Vector Sum model. Copy rights belong to original authors. Visit the link for more info Podcast created by Paper Player, LLC

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2022.09.16.507381v1?rss=1 Authors: Khoo, S. Y.-S., Samaha, A.-N. Abstract: After a history of intermittent cocaine intake, rats develop patterns of drug use characteristic of addiction. The dorsal striatum is involved in the increased pursuit of cocaine after intermittent drug self-administration experience. Within the dorsal striatum, chronic cocaine use changes metabotropic glutamate type II receptor (mGlu2/3) density and function. We examined the extent to which activity at these receptors mediates responding for cocaine after intermittent cocaine use. In Experiment 1, male Wistar rats (n = 11) self-administered 0.25 mg/kg/infusion cocaine during 10 daily intermittent access (IntA) sessions (5 min ON/25 min OFF, for 5 h/session). We then examined the effects of intra-dorsal striatum infusions of the mGlu2/3 receptor agonist LY379268 (0, 1, and 3 g/hemisphere) on cocaine self-administration under a progressive ratio schedule of reinforcement. We observed a non-significant tendency for LY379268 to reduce responding for cocaine. In Experiment 2, we used a larger sample of male (n = 11) and female (n = 10) rats. Across 10 IntA sessions, the sexes showed similar levels of cocaine intake. Across the sexes, locomotion significantly increased over sessions, suggesting that rats developed psychomotor sensitization to self-administered cocaine. After 10 IntA sessions, intra-dorsal striatum LY379268 significantly reduced breakpoints achieved for cocaine, active lever presses, and cocaine infusions earned under progressive ratio. LY379268 had no effects on locomotion or inactive lever presses, indicating no motor effects. These results suggest that mGlu2/3 receptor activation in the dorsal striatum suppresses incentive motivation for cocaine, and this holds promise for anti-addiction therapeutics. Copy rights belong to original authors. Visit the link for more info Podcast created by PaperPlayer

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.11.20.392027v1?rss=1 Authors: Witchey, S., Caldwell, H. K. Abstract: Oxytocin (Oxt) signaling via its receptor, the Oxt receptor (Oxtr), is important to the onset of mammalian maternal care. Specifically, evidence suggests that Oxt signaling around the time of parturition underlies the critical shift in how pups are perceived, i.e. from aversive stimuli to rewarding stimuli. Previous work from our lab has found that both Oxtr knockout (-/-) mice and forebrain-specific Oxtr knockout (FB/FB) are more likely than controls to abandon their first litters. Based on these data, we hypothesized that this observed pup abandonment phenotype was due to a failure of the brain to switch to a more maternal state. In order to identify where in the brain Oxt signaling contributes to the onset of maternal care we performed three experiments. In Experiment 1, virgin Oxtr FB/FB females were assessed for genotypic differences in maternal behavior and c-Fos expression following maternal sensitization was quantified. In Experiment 2, c-Fos expression was quantified in Oxtr -/- and Oxtr FB/FB females following parturition. In Experiment 3, based on our findings from Experiment 2, the Oxtr in the nucleus accumbens shell (NAcc) was genetically deleted in female Oxtr floxed mice (Oxtr Flox/Flox) mice using a Cre recombinase expressing adeno-associated virus. In Experiment 1, sensitized virgin Oxtr FB/FB females had significantly lower retrieval latencies on the first day of testing and reduced c-Fos expression in the dorsal lateral septum compared to controls. In Experiment 2, increased c-Fos expression was observed in the NAcc shell of both Oxtr -/- and Oxtr FB/FB dams as compared to controls. In Experiment 3, virally mediated knockout of the Oxtr in the NAcc shell completely disrupted the onset of maternal care. Thus, by genetically deleting Oxtr expression in the NAcc the pup abandonment phenotype previously observed in Oxtr -/- mice and Oxtr FB/FB dams was recreated. Taken together, these data suggest that in post-parturient mice, Oxtr expression in the NAcc shell is critical to the onset of maternal behavior. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.11.11.377614v1?rss=1 Authors: Yang, Y.-H., Liao, H.-I., Furukawa, S. Abstract: Pupillary response reflects not only ambient light changes but also top-down factors. Nevertheless, it remains inconclusive whether the conscious awareness modulates the pupillary response. We investigated pupillary responses to faces under different conscious conditions using continuous flash suppression (CFS). In Experiment 1 and 2, we used a breaking-CFS procedure in which participants had to detect the face from suppression. Results showed that the pupil constricted more to upright faces than to inverted faces before the face was detected, suggesting that pupillary responses reflect face processing entering consciousness. In Experiment 3 and 4, we used a fixed duration-CFS procedure with both objective performance and subjective reports. Different pupillary responses were observed only when the participant was aware of the face. These findings imply that the conscious awareness is critical for modulating autonomic neural circuits of the pupillary function. The corresponding pupillary responses may reflect dynamic processes underlying conscious awareness. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.11.06.368118v1?rss=1 Authors: Cracco, E., Lee, H., van Belle, G., Quenon, L., Haggard, P., Rossion, B., Orgs, G. Abstract: Humans and other animals have evolved to act in groups, but how does the brain distinguish multiple people moving in group from multiple people moving independently? Across three experiments, we test whether biological motion perception depends on the spatiotemporal relationships among people moving together. In Experiment 1, we apply EEG frequency tagging to apparent biological motion and show that fluently ordered sequences of body postures drive brain activity at three hierarchical levels of biological motion processing: image, body sequence, and movement. We then show that movement-, but not body- or image-related brain responses are enhanced when observing four agents moving in synchrony. Neural entrainment was strongest for fluently moving synchronous groups (Experiment 2), displayed in upright orientation (Experiment 3). Our findings show that the brain preferentially entrains to the collective movement of human agents, deploying perceptual organization principles of synchrony and common fate for the purpose of social perception. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.10.03.324640v1?rss=1 Authors: Kliesch, M., Giroud, N., Meyer, M. Abstract: In this pilot study, we evaluated the use of electrophysiological measures at rest as paradigm-independent predictors of L2 development for the first time in older adult learners. We then assessed EEG correlates of the learning outcome in a language-switching paradigm after the training, which to date has only been done in younger adults and at intermediate to advanced L2 proficiency. Ten (Swiss) German-speaking adults between 65-74 years of age participated in an intensive three-weeks English training for beginners. A resting-state EEG was recorded before the training to predict the ensuing L2 development (Experiment 1). A language-switching ERP experiment was conducted after the training to assess the learning outcome (Experiment 2). All participants improved their L2 skills but differed noticeably in their individual development. Experiment 1 showed that beta1 oscillations at rest (13-14.5Hz) predicted these individual differences. We interpret resting-state beta1 oscillations as correlates of attentional capacities and semantic working memory that facilitate the extraction and processing of novel forms and meanings from the L2 input. In Experiment 2, we found that language-switching from the L2 into the native language (L1) elicited an N400 component, which was reduced in the more advanced learners. Thus, for learners beginning the acquisition of an L2 in third age, language switching appears to become less effortful with increasing proficiency, suggesting that the lexicons of the L1 and L2 become more closely linked. In sum, our findings indicate that individual differences in L2 development and proficiency in older adults operate through similar electrophysiological mechanisms as those observed in younger adults. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.09.25.313551v1?rss=1 Authors: Kobor, A., Kardos, Z., Takacs, A., Elteto, N., Janacsek, K., Toth-Faber, E., Csepe, V., Nemeth, D. Abstract: Primarily encountered information has been shown to influence perceptual and memory processes. However, it has been scarcely investigated how initial risk probabilities influence subsequent risk-taking behavior in an environment with repeated decisions. Therefore, the present study tested in two experiments whether young adults adjusted their choice behavior in the Balloon Analogue Risk task after an unsignaled and unexpected change point. The change point separated early trials from subsequent ones. While mostly positive (more reward) or mostly negative (no reward) events characterized early trials, subsequent trials were unbiased. In Experiment 1, the change point occurred after one-sixth or one-third of the trials without intermittence whereas in Experiment 2, it occurred between separate task phases. In Experiment 1, if negative events characterized the early trials, after the change point, risk-taking behavior increased as compared with the early trials. Conversely, if positive events characterized the early trials, risk-taking behavior decreased after the change point. Although participants shifted their choice behavior, the difference in risk taking due to initial experience remained, especially when this experience involved only one-sixth of the trials. In Experiment 2, slower adjustment of risk-taking behavior was observed after initially experiencing negative events than positive or baseline events. However, as all participants overcame the effect of initial experience, they became more prone to take risks. Altogether, results of both experiments not only suggest the profound effect of early experience but also that individuals dynamically update their risk estimates to adapt to the continuously changing environment. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.09.01.277590v1?rss=1 Authors: Vlahou, E., Ueno, K., Shinn-Cunningham, B. G., Kopco, N. Abstract: Purpose: We examined how consonant perception is affected by a preceding speech carrier simulated in the same or a different room, for a broad range of consonants. Carrier room, carrier length, and carrier length/target room uncertainty were manipulated. A phonetic feature analysis tested which phonetic categories are most influenced by the acoustic context of the carrier. Method: Two experiments were performed, each with 9 participants. Targets consisted of vowel-consonant (VC) syllables presented in one of 2 strongly reverberant rooms, preceded by a VC carrier presented either in the same room, a different reverberant room, or an anechoic room. In Experiment 1 the carrier length and the target room randomly varied from trial to trial while in Experiment 2 they were fixed within blocks of trials. Results: Compared to the no-carrier condition, a consistent carrier provided only a small advantage for consonant perception, whereas inconsistent carriers disrupted performance significantly. For a different-room carrier, carrier length had an effect; performance dropped significantly in the 2-VC compared to the 4-VC carrier length. The only effect of carrier uncertainty was an overall drop in performance. Phonetic analysis showed that an inconsistent carrier significantly degraded identification of the manner of articulation, especially for stop consonants, and, in one of the rooms, also of voicing. Conclusions: Calibration of consonant perception to strong reverberation is exhibited through disruptions in perception when the room is switched. The strength of calibration varies across different consonants and phonetic features, as well as across rooms and durations of exposure to a given room. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.08.19.258046v1?rss=1 Authors: Lee, D., Holyoak, K. Abstract: In two experiments, people repeatedly judged individual options with respect to both overall value and attribute values. When required to choose between two snacks, each differing in two attributes (pleasure and nutrition), people's assessments of value shifted from pre- to post-choice in the direction that spread the alternatives further apart so as to favor the winner, thereby increasing confidence in the choice. This shift was observed not only for ratings of overall value, but also for each of the two individual attributes. The magnitude of the coherence shift increased with choice difficulty as measured by the difference in initial ratings of overall value for the two options, as well as with a measure of attribute disparity (the degree to which individual attributes "disagree" with one another as to which option is superior). In Experiment 2, a task requiring comparison of value similarity generated the same qualitative pattern of value and confidence changes, even though the similarity judgments entirely preceded the actual choice task. These findings support the hypothesis that active comparison of values is the core component of the decision process during which perceived values are shifted so as to more sharply distinguish the items being compared. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.08.11.246421v1?rss=1 Authors: Cruzat, J., Torralba, M., Ruzzoli, M., Fernandez, A., Deco, G., Soto-Faraco, S. Abstract: Several past studies have shown that attention and perception can depend upon the phase of ongoing neural oscillations at stimulus onset. Here, we extend this idea to the memory domain. We tested the hypothesis that ongoing fluctuations in neural activity have an impact on memory encoding using a picture paired-associates task to gauge episodic memory performance. Experiment 1 capitalized on the principle of phase reset. We tested if subsequent memory performance fluctuates rhythmically, time-locked to a reset cue presented before the to-be-remembered pairs. We found indication that behavioral performance was periodically and selectively modulated at theta frequency (~4 Hz). In Experiment 2 we focused on prestimulus ongoing activity using scalp EEG recorded while participants performed the pair-associate task. We analyzed subsequent memory performance as a function of theta and alpha activity around the presentation of the to-be-remembered pairs. The results of the pre-registered analyses, using large electrode clusters and generic spectral ranges, returned null results of prestimulus phase-behavior correlation. However, we found that post-stimulus theta-power modulations in left frontal scalp predicted subsequent memory performance. This post-stimulus effect in theta power was used to guide a post-hoc prestimulus phase analysis, narrowed down to more precise scalp location and frequency. This analysis returned a correlation between prestimulus theta phase and subsequent memory. Altogether, these results suggest that the prestimulus theta activity at encoding has an impact on later memory performance. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.08.01.232314v1?rss=1 Authors: Ulbrich, P., Gail, A. Abstract: Ongoing goal-directed movements can be rapidly adjusted following new environmental information, e.g. when chasing pray or foraging. This makes movement trajectories in go-before-you-know decision-making a suitable behavioral readout of the ongoing decision process. Yet, existing methods of movement analysis are often based on statistically comparing two groups of trial-averaged trajectories and are not easily applied to three-dimensional data, preventing them from being applicable to natural free behavior. We developed and tested the cone method to estimate the point of overt commitment (POC) along a single two- or three-dimensional trajectory, i.e. the position where movement is adjusted towards a newly selected spatial target. In Experiment 1, we established a ground truth data set in which the cone method successfully identified the experimentally constrained POCs across a wide range of all but the shallowest adjustment angles. In Experiment 2, we demonstrate the power of the method in a typical decision-making task with expected decision time differences known from previous findings. The POCs identified by cone method matched these expected effects. In both experiments, we compared the cone method's single trial performance with a trial-averaging method and obtained comparable results. We discuss the advantages of the single-trajectory cone method over trial-averaging methods and possible applications beyond the examples presented in this study. The cone method provides a distinct addition to existing tools used to study decisions during ongoing movement behavior, which we consider particularly promising towards studies of non-repetitive free behavior. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.07.28.225060v1?rss=1 Authors: Townsend, E. A. Abstract: Rationale: Strategies are needed to decrease the abuse liability of mu opioid receptor (MOR) agonists. One strategy under consideration is to combine MOR agonists with kappa opioid receptor (KOR) agonists. Objectives: The effects of KOR-agonists (U50488, nalfurafine) on fentanyl-versus-food choice were compared under conditions where the KOR agonists were added to the self-administered fentanyl (contingent delivery) or administered as pretreatments (non-contingent delivery) in male and female rats. The effects of increasing and decreasing the magnitude of the alternative food reinforcer were also determined. Methods: Rats were trained to respond under a concurrent schedule of fentanyl (0, 0.32-10 g/kg/infusion) and food reinforcement. In Experiment 1, U50488 and nalfurafine were co-administered with fentanyl as fixed-proportion mixtures (contingent administration). In Experiment 2, U50488 (1-10 mg/kg) and nalfurafine (3.2-32 g/kg) were administered as acute pretreatments (non-contingent administration). nor-BNI (32 mg/kg) was administered prior to contingent and non-contingent KOR-agonist treatment in Experiment 3. Experiment 4 evaluated the effects of increasing and decreasing the magnitude of the non-drug reinforcer. Results: Both U50488 and nalfurafine decreased fentanyl choice when administered contingently, demonstrating that KOR agonists punish opioid choice. Non-contingent U50488 and nalfurafine administration decreased rates of fentanyl and food self-administration without altering fentanyl choice. Both contingent and non-contingent U50488 and nalfurafine effects on fentanyl choice were attenuated by nor-BNI. Fentanyl choice was sensitive to increases and decreases in the magnitude of the non-drug reinforcer. Conclusions: These results demonstrate that the effects of KOR agonists on fentanyl reinforcement are dependent upon the contingencies under which they are administered. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.07.19.210781v1?rss=1 Authors: Wen, W., Zhang, Y., Li, S. Abstract: Prior information about distractor facilitates selective attention to task-relevant items and helps the optimization of oculomotor planning. Particularly, feature-based attentional inhibition could be benefited from the pre-knowledge of critical features of the distractors. In the present study, we capitalized on gaze-position decoding to examine the dynamics of attentional deployment in a feature-based attentional task that involved two groups of dots (target/distractor dots) moving toward different directions. Specifically, this measurement revealed how pre-knowledge of the target's or distractor's direction modulated real-time feature-based attentional bias. In Experiment 1, participants were provided with target cues indicating the moving direction of target dots. The results showed that participants were biased towards the cued direction and tracked the target dots throughout the task period. In Experiment 2 and Experiment 3, participants were provided with cues that informed the moving direction of distractor dots. The results showed that participants would continuously monitor the distractor's direction when the distractor cue varied on a trial-by-trial basis (Experiment 2). However, when the to-be-ignored distractor direction remained constant (Experiment 3), participants would strategically bias their attention to the distractor's direction before the cue onset and reduce the cost of re-deployment of attention between trials. These results suggest that monitoring the distractor's feature is a prerequisite for feature-based attentional inhibition and this process is facilitated by the predictability of the distractor's feature. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.07.06.190397v1?rss=1 Authors: Liu, Y., Block, H. J. Abstract: Motor skill learning involves both sensorimotor adaptation (calibrating the response to task dynamics and kinematics), and sequence learning (executing the task elements in the correct order at the necessary speed). These processes typically occur together in natural behavior and share much in common, such as working memory demands, development, and possibly neural substrates. However, sensorimotor and sequence learning are usually studied in isolation in research settings, for example as force field adaptation or serial reaction time tasks (SRTT), respectively. It is therefore unclear whether having predictive sequence information during sensorimotor adaptation would facilitate performance, perhaps by improving sensorimotor planning, or if it would impair performance, perhaps by occupying neural resources needed for sensorimotor learning. Here we evaluated adaptation to a distance-dependent force field in two different SRTT contexts: In Experiment 1, 28 subjects reached between 4 targets in a sequenced or random order. In Experiment 2, 40 subjects reached to one target, but 3 force field directions were applied in a sequenced or random order. We did not observe any consistent influence of target position sequence on force field adaptation in Experiment 1. However, sequencing of force field directions facilitated sensorimotor adaptation and retention in Experiment 2. This is inconsistent with the idea that sensorimotor and sequence learning share neural resources in any mutually exclusive fashion. These findings indicate that under certain conditions, perhaps especially when the sequence is related to the sensorimotor perturbation itself as in Experiment 2, sequence learning may interact with sensorimotor learning in a facilitatory manner. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.07.01.181826v1?rss=1 Authors: Darnell, M., Lamy, D. Abstract: In visual search, improved performance when a target appears at a recently cued location is taken as strong evidence that attention was shifted to this cue. Here, we provide evidence challenging the canonical interpretation of spatial-cueing (or cue-validity) effects and supporting the Priority Accumulation Framework (PAF). According to PAF, attentional priority accumulates over time at each location until the search context triggers selection of the highest-priority location. Spatial-cueing effects reflect how long it takes to resolve the competition and can thus be observed even when attention was never shifted to the cue. Here, we used a spatial-cueing paradigm with abruptly onset cues and search displays varying in target-distractor similarity. We show search performance on valid-cue trials deteriorated the more difficult the search, a finding that is incompatible with the standard interpretation of spatial-cueing effects. By using brief displays (Experiment 1) and by examining the effect of search difficulty on the fastest trials (Experiment 2), we invalidate alternative accounts invoking post-perceptual verification processes (Experiment 1) or occasional failures of the onset cue to capture attention (Experiment 2). In Experiment 3, we used a combination of the spatial-cueing and dot-probe paradigms. We show that the events that occurred in both the cue and search displays affected attentional distribution, and that the relative attentional priority weight that accumulated at the target location determined how easily the competition was resolved. These findings fully support PAFs predictions. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.06.28.176131v1?rss=1 Authors: Race, E., Carlisle, C., Tejwani, R., Verfaellie, M. Abstract: Accumulating evidence suggests that the hippocampus plays a critical role in the creative and flexible use of language. For example, amnesic patients with hippocampal damage produce less coherent and cohesive verbal discourse when constructing narratives about the past, present, and future. A recent study by Hilverman and colleagues (2017) found that amnesic patients with hippocampal damage also use less imageable words during narrative construction compared to healthy controls. These results suggest that in addition to supporting language use at the discourse level, the hippocampus also influences the quality of language at the single word level. However, the generalizability of these results to different types of language production tasks and the relationship to patients' broader impairments in episodic memory have yet to be examined. In the current study, we investigated whether amnesic patients with hippocampal damage produce less imageable words compared to healthy controls in two different types of language production tasks. In Experiment 1, participants constructed narratives about events depicted in visually presented pictures (picture narratives). In Experiment 2, participants constructed verbal narratives about remembered events from the past or simulated events in the future (past/future narratives). Across all types of narratives, patients produced words that were rated as having similar levels of imageability compared to controls. Importantly, this was the case both in patients' picture narratives, which did not require generating details from long-term memory and were matched to controls' with respect to narrative content, and in patients' narratives about past/future events, which required generating details from long-term memory and which were reduced in narrative content compared to those of controls. These results reveal that the hippocampus is not necessary for the use of imageable representations at the linguistic level, and that hippocampal contributions to imageable word use are independent of hippocampal contributions to episodic memory. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.06.26.170761v1?rss=1 Authors: van Bree, S., Sohoglu, E., Davis, M. H., Zoefel, B. Abstract: Rhythmic sensory or electrical stimulation will produce rhythmic brain responses. These rhythmic responses are often interpreted as endogenous neural oscillations aligned to the stimulus rhythm. However, stimulus-aligned brain responses can also be explained as a sequence of evoked responses, which only appear regular due to the rhythmicity of the stimulus, without necessarily involving underlying neural oscillations. To distinguish evoked responses from true oscillatory activity, we tested whether rhythmic stimulation produces oscillatory responses which continue after the end of the stimulus. Such sustained effects provide evidence for true involvement of neural oscillations. In Experiment 1, we found that rhythmic intelligible, but not unintelligible speech produces oscillatory responses in magnetoencephalography (MEG) which outlast the stimulus at parietal sensors. In Experiment 2, we found that transcranial alternating current stimulation (tACS) leads to rhythmic fluctuations in speech perception outcomes which continue after the end of electrical stimulation. We further report that the phase relation between electroencephalography (EEG) and rhythmic intelligible speech can predict the tACS phase that leads to most accurate speech perception. Together, our results lay the foundation for a new account of speech perception which includes endogenous neural oscillations as a key underlying principle. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.06.23.167965v1?rss=1 Authors: Gomez, I. N., Ormiston, K., Greenhouse, I. Abstract: Action preparation involves widespread modulation of motor system excitability, but the precise mechanisms are unknown. In this study, we investigated whether intracortical inhibition changes in task-irrelevant muscle representations during action preparation. We used transcranial magnetic stimulation (TMS) combined with electromyography in healthy human adults to measure motor evoked potentials (MEPs) and cortical silent periods (CSPs) in task-irrelevant muscles during the preparatory period of simple delayed response tasks. In Experiment 1, participants responded with the left-index finger in one task condition and the right-index finger in another task condition, while MEPs and CSPs were measured from the contralateral non-responding and tonically contracted index finger. During Experiment 2, participants responded with the right pinky finger while MEPs and CSPs were measured from the tonically contracted left-index finger. In both experiments, MEPs and CSPs were compared between the task preparatory period and a resting intertrial baseline. The CSP duration during response preparation decreased from baseline in every case. A laterality difference was also observed in Experiment 1, with a greater CSP reduction during the preparation of left finger responses compared to right finger responses. MEP amplitudes showed no modulation during movement preparation in any of the three response conditions. These findings indicate cortical inhibition associated with task-irrelevant muscles is transiently released during action preparation and implicate a novel mechanism for the controlled and coordinated release of motor cortex inhibition. Copy rights belong to original authors. Visit the link for more info

Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.06.09.143081v1?rss=1 Authors: Wang, Z., Murai, Y., Whitney, D. Abstract: Perceiving the positions of objects is a prerequisite for most other visual and visuomotor functions, but human perception of object position varies from one individual to the next. The source of these individual differences in perceived position and their perceptual consequences are unknown. Here, we tested whether idiosyncratic biases in the underlying representation of visual space propagate across different levels of visual processing. In Experiment 1, using a position matching task, we found stable, observer-specific compressions and expansions within local regions throughout the visual field. We then measured Vernier acuity (Experiment 2) and perceived size of objects (Experiment 3) across the visual field and found that individualized spatial distortions were closely associated with variations in both visual acuity and apparent object size. Our results reveal idiosyncratic biases in perceived position and size, originating from a heterogeneous spatial resolution that carries across the visual hierarchy. Copy rights belong to original authors. Visit the link for more info

Although a substantial literature is developing regarding the effects of stress on decision-making (cf. Mather & Lighthall, 2012), the literature on stress and social decision-making is still in the beginning stage. The present research extends this new literature by examining the mediating and moderating factors of the effect of stress on social decision-making. Furthermore, a novel aspect of the research is its effort to connect the information-processing and functional perspectives, with regard to the acute stress response. Dual-mode theories state that emotional processing, relative to cognitive processing, occurs early during information processing (Murphy & Zajonc, 1993) and is associated with stimulus-driven behaviors (Mischel & Metcalfe, 1999). Therefore, an intensification of emotional processing and inhibition of cognitive control processes may lead to an earlier and more stimulus-driven initiation of behavioral responses than under normal circumstances. Moreover, such quick, automatic behavioral responses to environmental stimuli may be particularly useful during an acute stress response in that such responses could help prevent disturbances to homeostasis (Nesse, 2005). In order to facilitate such quick, automatic behavioral responses, emotional processing may be intensified and cognitive processing inhibited, during an acute stress response. In support of this notion, empirical findings show that acute stress increases emotion-related phenomena, such as reward salience (cf. Mather & Lighthall, 2012) and emotional learning (Luethi, Meier, & Sandi, 2008). However, in a social decision-making context, such enhancement of emotional processing may negatively affect the social interactions, such that negative emotions from perceived unfairness may be amplified when people are undergoing an acute stress response. More specifically, in the context of an Ultimatum Game, people who are stressed may reject more unfair offers than people under normal conditions. This research tested this main hypothesis, and examined emotions and trait emotion regulation tendencies as mediating and moderating factors, respectively, of the relationship between acute stress and Ultimatum Game rejections. These arguments are elaborated in Chapters 1, 2, and 3 of this dissertation. In two experiments, participants played the Ultimatum Game as the Responder after completing a stress or control task. The Cold Pressor Test was used as the stress induction method. Before and after the Ultimatum Game, participants completed state emotion ratings as well as trait emotion regulation questionnaires. Results from Experiment 1 showed a successful stress induction, indicated by higher cortisol levels in the stress, relative to control, group. Moreover, Experiment 1 revealed a significant Stress x Amount interaction, with stress having an effect on rejections of unfair offers, in comparison to fair offers. However, the emotion and emotion regulation results did not indicate the expected pattern, with emotions being uncorrelated with fair, nor unfair offers, and emotion regulation being associated with reduced rejections of fair, but not unfair, offers. In Experiment 2, an experimental manipulation designed to influence negative emotions, namely partner type, was employed. Results did not replicate the results of the first experiment, but unexpected results were found involving partner type and negative emotions, namely that participants who played with human partners, relative to those who played with computer partners, rejected more unfair offers and that negative emotions were positively correlated with rejections of fair and unfair offers. The experiments and their results are described in Chapter 4. It is difficult to draw firm conclusions from these results, but they do offer a starting point for interesting future research questions. Chapter 5 discusses some implications as well as limitations of the present research.

Previous studies have shown that in tasks requiring participants to report the direction of apparent motion, task-irrelevant mono-beeps can "capture" visual motion perception when the beeps occur temporally close to the visual stimuli. However, the contributions of the relative timing of multimodal events and the event structure, modulating uni- and/or crossmodal perceptual grouping, remain unclear. To examine this question and extend the investigation to the tactile modality, the current experiments presented tactile two-tap apparent-motion streams, with an SOA of 400 ms between successive, left-/right-hand middle-finger taps, accompanied by task-irrelevant, non-spatial auditory stimuli. The streams were shown for 90 seconds, and participants' task was to continuously report the perceived (left- or rightward) direction of tactile motion. In Experiment 1, each tactile stimulus was paired with an auditory beep, though odd-numbered taps were paired with an asynchronous beep, with audiotactile SOAs ranging from -75 ms to 75 ms. Perceived direction of tactile motion varied systematically with audiotactile SOA, indicative of a temporal-capture effect. In Experiment 2, two audiotactile SOAs--one short (75 ms), one long (325 ms)--were compared. The long-SOA condition preserved the crossmodal event structure (so the temporal-capture dynamics should have been similar to that in Experiment 1), but both beeps now occurred temporally close to the taps on one side (even-numbered taps). The two SOAs were found to produce opposite modulations of apparent motion, indicative of an influence of crossmodal grouping. In Experiment 3, only odd-numbered, but not even-numbered, taps were paired with auditory beeps. This abolished the temporal-capture effect and, instead, a dominant percept of apparent motion from the audiotactile side to the tactile-only side was observed independently of the SOA variation. These findings suggest that asymmetric crossmodal grouping leads to an attentional modulation of apparent motion, which inhibits crossmodal temporal-capture effects.

Episodic memory, i.e. memorization of information within a spatiotemporal environment, is affected by Alzheimer's disease (AD) but its loss may also occur in the normal aging process. The purpose of this study is to analyze and evaluate episodic memory in patients with AD by examining their cognitive skills in episodic memory through the introspection technique. A new method was used, wherein we assessed mental images of the subject's own past recalled in the mind like projected pictures and movies. Experiment 1 is designed to determine the effect and process of normal and pathological aging on cognitive skills in episodic memory using the introspection technique. Two groups were observed towards this purpose: 21 patients with AD and 19 normal control subjects. All subjects were chosen from ages from 55 to 70 and were administered standardized neuropsychological tests (K-DRS and MMSE-K). All subjects were asked to retrieve their episodic memory of the previous day, week, month, and a day remote from testing day. The answers were analyzed, focusing on their specific features such as emotional state, color, and time order. In the following day, the subjects were tasked to recall again all images that they reproduced in the previous day's test in order to observe impairment of anterograde memory. Results showed that patients failed to arrange the retrieved images in time order and their images of the previous day were unclear in color and were stationary like photographs, even when they reproduced the mental images at as much quantity as controls. They also could not remember particular events of yesterday, only their general occurrence. These results suggest that in the early stage of AD, difficulties in the retrieval of recent episodic memory begin to occur, and qualitative impairment happens earlier than quantitative. The third chapter supports these results with further evidence, analyzing from a clinical viewpoint 3 patients with AD, 1 patient with mild depression and 2 controls. In Experiment 2 the emotional intensity of episodic memory within different categories of memory (yesterday, week, month, and remote) was investigated by comparing healthy elderly people and AD patients. The subjects’ voice intonations were estimated by 8 valuators. As a result, the emotional intensity of AD patient was evaluated lower than controls. It appears that patients in the early stage of AD are impaired in the ability to express emotions during emotional episodic memory retrieval compared to healthy elderly adults.

Die präfrontale repetitive transkranielle Magnestimulation (rTMS) wird seit den 90er Jahren angewendet, um einerseits die Bedeutung des präfrontalen Kortex für verschiedene kognitive und affektive Prozesse zu erforschen und andererseits die Pathophysiologie psychiatrischer Erkrankungen zu untersuchen und therapeutisch zu modulieren. Von neuen Stimulationsprotokollen, wie der Theta Burst Stimulation (TBS), die analog zum Tiermodell zur Induktion von Langzeitpotenzierung beim Menschen entwickelt wurde, werden stärkere und länger anhaltende therapeutische Effekte erhofft. Im Gegensatz zur Stimulation des Motorkortex wurde die präfrontale rTMS bislang kaum neurophysiologisch untersucht. In dieser Arbeit werden daher zwei Experimente beschrieben, in denen eine niederfrequente 1 Hz-rTMS und TBS bezüglich ihrer Effekte auf ereigniskorrelierte Potentiale (EKP) in GoNogo-Aufgaben charakterisiert wurden. Sie verfolgten die Fragestellungen, ob EKP analog zu motorisch evozierten Potenzialen (MEP) geeignet sind die Wirkungsweise einer präfrontalen rTMS einzuschätzen und ob sich die TBS qualitativ oder quantitativ von herkömmlichen rTMS-Protokollen unterscheidet (Experiment 1 und 3). In einem Vorexperiment zu Experiment 3 (Experiment 2) wurde erstmals die Sicherheit verschiedener präfrontaler TBS-Formen mittels EEG und kognitiver Tests untersucht. In Experiment 1 wurden 18 gesunde Probanden mit einer als inhibitorisch geltenden 1 Hz rTMS über dem linken dorsolateralen präfrontalen Kortex (DLPFC), dem medialen präfrontalen Kortex (mPFC) und einer Kontrollregion stimuliert. Bei der nachfolgenden Bearbeitung einer GoNogo-Aufgabe, zeigte sich eine Vergrößerung der P3-Amplitude nach Stimulation des mPFC bei zeitgleich größerer parietaler Aktivität. Hypothesenkonform konnte eine Reduktion der N2-Amplitude bei Stimulation des linken DLPFC gefunden werden. Während der rTMS-Effekt auf die P3-Amplitude am besten durch die Initiierung von Aufmerksamkeitsprozessen erklärt werden kann, spricht der Einfluss der 1 Hz-rTMS über dem linken DLPFC für einen inhibitorischen Effekt auf kortikaler Ebene (Experiment 1). Im Hinblick auf die vorbeschriebenen nachhaltigeren Effekte von TBS-Protokollen am Motorkortex wurde in Experiment 2 die TBS am präfrontalen Kortex bei 24 gesunden Probanden plazebo-kontrolliert bezüglich ihrer Sicherheit untersucht, um diese als innovative Stimulationsform für weitere Experimente einsetzbar zu machen. Die Ergebnisse dieses Experimentes zeigten, dass eine präfrontale, als inhibitorisch geltende TBS (continuous TBS - cTBS) und eine als exzitatorisch geltende TBS (intermittent TBS - iTBS) keine epilepsietypischen Potenziale im EEG oder epileptische Anfälle triggerten. Es kamen jedoch bei drei von 25 Probanden vagale Reaktionen vor, deren Auftreten beachtet und deren Ursache in weiteren Studien erforscht werden sollte. In den neuropsychologischen Untersuchungen wurde eine verminderte Leistung im Arbeitsgedächtnis und in einer frontalen Testbatterie (Trend) nach iTBS des linken DLPFC und in der Anzahl der ‚false alarms’ einer GoNogo-Aufgabe nach cTBS des mPFC festgestellt. Diese Veränderungen spiegelten sich auch in neurophysiologischen Parametern wider. Eine Analyse der EEG-Daten mittels standardized low resolution brain electromagnetic tomography (sLORETA) ergab eine Zunahme der Aktivität im Alpha 2-Band links präfrontal nach iTBS des linken DLPFC, die bis zu einer Stunde nachweisbar blieb und einen Zusammenhang mit den Leistungen im Arbeitsgedächtnis und der frontalen Testbatterie zeigte. In Experiment 3 wurden dann 1 Hz rTMS, cTBS und eine Plazebostimulation bei 9 gesunden Probanden miteinander verglichen. Alle Stimulationen erfolgten neuronavigiert bezogen auf eine Aktivierung im individuellen funktionellen Magnetresonanztomographie (fMRT) Bild, die während der Entscheidungskomponente (Volition) einer modifizierten GoNogo-Aufgabe gefunden wurde. Hierbei konnte die in Experiment 1 beobachtete inhibitorische Wirkung der 1 Hz rTMS auf eine relevante EKP-Komponente (N2P2-peak-to-peak-Amplitude) analog repliziert werden (Trend). Bei einer zeitlichen Betrachtung der Stromdichten mittels sLORETA ließ sich deskriptiv eine Verminderung nach 1 Hz rTMS beobachten, während sich der Verlauf der Stromdichten in der cTBS-Bedingung abhängig vom Aktivierungszustand des Kortex zu ändern schien. In einer für ‚conflict monitoring’ relevanten region of interest (ROI) konnte in dem für die N2P2-Amplitude relevanten Zeitfenster eine Verminderung (Trend) der Stromdichte in der 1 Hz-Bedingung gefunden werden, die mit der N2P2-Amplitude korrelierte. Desweiteren waren in Experiment 1 und 3 keine Effekte auf Verhaltensdaten und EKP-Latenzen nachweisbar. Die Ergebnisse dieser Arbeit sprechen dafür, dass die gemeinsame Betrachtung von Verhaltensdaten, EKP- und Stromdichteanalysen eine neurophysiologische Interpretation der rTMS erlaubt. Die alleinige Verwendung von EKP zur Beurteilung der Wirkungsweise einer präfrontalen rTMS hingegen ist methodisch und inhaltlich begrenzt. Am präfrontalen Kortex zeigten cTBS und iTBS andere Effekte als für den Motorkortex vorbeschrieben. Insgesamt betrachtet sprechen die Ergebnisse dafür, dass sich die TBS nicht nur quantitativ sondern auch qualitativ von einer 1 Hz rTMS unterscheidet. Nach diesen Pilotexperimenten stellt die Untersuchung rTMS-vermittelter Effekte auf präfrontal generierte EKP einen vielversprechenden Untersuchungsansatz dar, um die Bedeutung präfrontaler Regionen als Generatoren spezifischer EKP-Komponenten zu erforschen, die Wirkung verschiedener rTMS Protokolle neurophysiologisch zu untersuchen und diese Protokolle für experimentelle oder therapeutische Anwendungen weiter zu entwickeln. So könnte die Wirkung spezifischer TBS-Protokolle durch eine pathologisch veränderte Grundaktivität bei Patienten mit psychiatrischen Erkrankungen im Gegensatz zu gesunden Probanden verändert sein. Dies könnte in einem nächsten Schritt mit dem oben beschriebenen Untersuchungsansatz näher erforscht werden.