A multimodal cortical network of sensory expectation violation revealed by fMRI.

The brain is subjected to multi-modal sensory information in an environment governed by statistical dependencies. Mismatch responses (MMRs), classically recorded with EEG, have provided valuable insights into the brain's processing of regularities and the generation of corresponding sensory predictions. Only few studies allow for comparisons of MMRs across multiple modalities in a simultaneous sensory stream and their corresponding cross-modal context sensitivity remains unknown. Here, we used a tri-modal version of the roving stimulus paradigm in fMRI to elicit MMRs in the auditory, somatosensory and visual modality. Participants (N = 29) were simultaneously presented with sequences of low and high intensity stimuli in each of the three senses while actively observing the tri-modal input stream and occasionally reporting the intensity of the previous stimulus in a prompted modality. The sequences were based on a probabilistic model, defining transition probabilities such that, for each modality, stimuli were more likely to repeat (p = .825) than change (p = .175) and stimulus intensities were equiprobable (p = .5). Moreover, each transition was conditional on the configuration of the other two modalities comprising global (cross-modal) predictive properties of the sequences. We identified a shared mismatch network of modality general inferior frontal and temporo-parietal areas as well as sensory areas, where the connectivity (psychophysiological interaction) between these regions was modulated during mismatch processing. Further, we found deviant responses within the network to be modulated by local stimulus repetition, which suggests highly comparable processing of expectation violation across modalities. Moreover, hierarchically higher regions of the mismatch network in the temporo-parietal area around the intraparietal sulcus were identified to signal cross-modal expectation violation. With the consistency of MMRs across audition, somatosensation and vision, our study provides insights into a shared cortical network of uni- and multi-modal expectation violation in response to sequence regularities.

EEG mismatch responses in a multimodal roving stimulus paradigm provide evidence for probabilistic inference across audition, somatosensation, and vision.

The human brain is constantly subjected to a multimodal stream of probabilistic sensory inputs. Electroencephalography (EEG) signatures, such as the mismatch negativity (MMN) and the P3, can give valuable insight into neuronal probabilistic inference. Although reported for different modalities, mismatch responses have largely been studied in isolation, with a strong focus on the auditory MMN. To investigate the extent to which early and late mismatch responses across modalities represent comparable signatures of uni- and cross-modal probabilistic inference in the hierarchically structured cortex, we recorded EEG from 32 participants undergoing a novel tri-modal roving stimulus paradigm. The employed sequences consisted of high and low intensity stimuli in the auditory, somatosensory and visual modalities and were governed by unimodal transition probabilities and cross-modal conditional dependencies. We found modality specific signatures of MMN (~100-200 ms) in all three modalities, which were source localized to the respective sensory cortices and shared right lateralized prefrontal sources. Additionally, we identified a cross-modal signature of mismatch processing in the P3a time range (~300-350 ms), for which a common network with frontal dominance was found. Across modalities, the mismatch responses showed highly comparable parametric effects of stimulus train length, which were driven by standard and deviant response modulations in opposite directions. Strikingly, P3a responses across modalities were increased for mispredicted stimuli with low cross-modal conditional probability, suggesting sensitivity to multimodal (global) predictive sequence properties. Finally, model comparisons indicated that the observed single trial dynamics were best captured by Bayesian learning models tracking unimodal stimulus transitions as well as cross-modal conditional dependencies.

Dissociating Perceptual Awareness and Postperceptual Processing: The P300 Is Not a Reliable Marker of Somatosensory Target Detection.

A central challenge in the study of conscious perception lies in dissociating the neural correlates of perceptual awareness from those reflecting its precursors and consequences. No-report paradigms have been instrumental in this endeavor, demonstrating that the event-related potential P300, recorded from the human scalp, reflects reports rather than awareness. However, these paradigms cannot probe the degree to which stimuli are consciously processed from trial to trial and, thus, leave open the possibility that the P300 is a genuine correlate of conscious access enabling reports. Here, instead of removing report requirements, we took the opposite approach and equated postperceptual task demands across conscious and unconscious trials by orthogonalizing target detection and overt reports in a somatosensory detection task. We used Bayesian model selection to track the transformation from physical to perceptual processing stages in the EEG data of 24 male and female participants and show that the early P50 component scaled with physical stimulus intensity, whereas the N140 component was the first correlate of target detection. The late P300 component was elicited for both perceived and unperceived stimuli and was not substantially modulated by target detection. This was in stark contrast to a control experiment using a classical direct report task, which replicated the P50 and N140 effects but additionally showed a strong effect of target detection in the P300 time range. Our results demonstrate the task dependence of the P300 in the somatosensory modality and show that late cortical potentials dissociate from perceptual awareness even when stimuli are always reported.SIGNIFICANCE STATEMENT The time it takes for sensory information to enter our conscious experience can be an indicator of the neural processing stages that lead to perceptual awareness. However, because many cognitive processes routinely correlate with perception, isolating those signals that uniquely reflect perceptual awareness is not a trivial task. Here, we show that late electroencephalography signals cease to correlate with somatosensory awareness when common task confounds are controlled. Importantly, by balancing report requirements instead of abolishing them, we show that the lack of late effects cannot be explained by a lack of conscious access. Instead, we propose that conscious access occurs earlier, at ∼150 ms, supporting the view that early activity in sensory cortices is a neural correlate of conscious perception.

Differences in working memory coding of biological motion attributed to oneself and others.

The question how the brain distinguishes between information about self and others is of fundamental interest to both philosophy and neuroscience. In this functional magnetic resonance imaging (fMRI) study, we sought to distinguish the neural substrates of representing a full-body movement as one's movement and as someone else's movement. Participants performed a delayed match-to-sample working memory task where a retained full-body movement (displayed using point-light walkers) was arbitrarily labeled as one's own movement or as performed by someone else. By using arbitrary associations we aimed to address a limitation of previous studies, namely that our own movements are more familiar to us than movements of other people. A searchlight multivariate decoding analysis was used to test where information about types of movement and about self-association was coded. Movement specific activation patterns were found in a network of regions also involved in perceptual processing of movement stimuli, however not in early sensory regions. Information about whether a memorized movement was associated with the self or with another person was found to be coded by activity in the left middle frontal gyrus (MFG), left inferior frontal gyrus (IFG), bilateral supplementary motor area, and (at reduced threshold) in the left temporoparietal junction (TPJ). These areas are frequently reported as involved in action understanding (IFG, MFG) and domain-general self/other distinction (TPJ). Finally, in univariate analysis we found that selecting a self-associated movement for retention was related to increased activity in the ventral medial prefrontal cortex.

Neural surprise in somatosensory Bayesian learning.

Tracking statistical regularities of the environment is important for shaping human behavior and perception. Evidence suggests that the brain learns environmental dependencies using Bayesian principles. However, much remains unknown about the employed algorithms, for somesthesis in particular. Here, we describe the cortical dynamics of the somatosensory learning system to investigate both the form of the generative model as well as its neural surprise signatures. Specifically, we recorded EEG data from 40 participants subjected to a somatosensory roving-stimulus paradigm and performed single-trial modeling across peri-stimulus time in both sensor and source space. Our Bayesian model selection procedure indicates that evoked potentials are best described by a non-hierarchical learning model that tracks transitions between observations using leaky integration. From around 70ms post-stimulus onset, secondary somatosensory cortices are found to represent confidence-corrected surprise as a measure of model inadequacy. Indications of Bayesian surprise encoding, reflecting model updating, are found in primary somatosensory cortex from around 140ms. This dissociation is compatible with the idea that early surprise signals may control subsequent model update rates. In sum, our findings support the hypothesis that early somatosensory processing reflects Bayesian perceptual learning and contribute to an understanding of its underlying mechanisms.

Response modality-dependent categorical choice representations for vibrotactile comparisons.

Previous electrophysiological studies in monkeys and humans suggest that premotor regions are the primary loci for the encoding of perceptual choices during vibrotactile comparisons. However, these studies employed paradigms wherein choices were inextricably linked with the stimulus order and selection of manual movements. It remains largely unknown how vibrotactile choices are represented when they are decoupled from these sensorimotor components of the task. To address this question, we used fMRI-MVPA and a variant of the vibrotactile frequency discrimination task which enabled the isolation of choice-related signals from those related to stimulus order and selection of the manual decision reports. We identified the left contralateral dorsal premotor cortex (PMd) and intraparietal sulcus (IPS) as carrying information about vibrotactile choices. Our finding provides empirical evidence for an involvement of the PMd and IPS in vibrotactile decisions that goes above and beyond the coding of stimulus order and specific action selection. Considering findings from recent studies in animals, we speculate that the premotor region likely serves as a temporary storage site for information necessary for the specification of concrete manual movements, while the IPS might be more directly involved in the computation of choice. Moreover, this finding replicates results from our previous work using an oculomotor variant of the task, with the important difference that the informative premotor cluster identified in the previous work was centered in the bilateral frontal eye fields rather than in the PMd. Evidence from these two studies indicates that categorical choices in human vibrotactile comparisons are represented in a response modality-dependent manner.

Rehearsal of tactile working memory: Premotor cortex recruits two dissociable neuronal content representations.

Recent working memory (WM) research has focused on identifying brain regions that retain different types of mental content. Only few neuroimaging studies have explored the mechanism of attention-based refreshing, which is a type of rehearsal and is thought to implement the dynamic components of WM allowing for update of WM contents. Here, we took advantage of the distinct coding properties of the superior parietal lobe (SPL), which retains spatial layout information, and the right inferior frontal gyrus (IFG), which retains frequency information of vibrotactile stimuli during tactile WM. In an fMRI delayed match-to-sample task, participants had to internally rehearse sequences of spatial layouts or vibratory frequencies. Our results replicate the dissociation of SPL and IFG for the retention of layout and frequency information in terms of activation differences between conditions. Additionally, we found strong premotor cortex (PMC) activation during rehearsal of either stimulus type. To explore interactions between these regions we used dynamic causal modeling and found that activation within the network was best explained by a model that allows the PMC to drive activity in the SPL and IFG during rehearsal. This effect was content-specific, meaning that the PMC showed stronger influence on the SPL during pattern rehearsal and stronger influence on the IFG during frequency rehearsal. In line with previously established PMC contributions to sequence processing, our results suggest that it acts as a content-independent area that flexibly recruits content-specific regions to bring a WM item into the focus of attention during the rehearsal of tactile stimulus sequences.

Representation of visual numerosity information during working memory in humans: An fMRI decoding study.

Both animal and human studies on numerosity have shown the importance of the parietal cortex for numerosity processing. However, most studies have focused on the perceptual processing of numerosity. Still, it is unclear how and where numerosity information is coded when this information is retained during a working memory delay phase. Such temporal storage could be realized by the same structures as perceptual processes, or be transformed to a more abstract representation, potentially involving prefrontal regions. FMRI decoding studies allow the identification of brain areas that exhibit multi-voxel activation patterns specific to the content of working memory. Here, we used an assumption-free searchlight-decoding approach to test where numerosity-specific codes can be found during a 12 s retention period. Participants (n = 24) performed a retro-cue delayed match-to-sample task, in which numerosity information was presented as visual dot arrays. We found mnemonic numerosity-specific activation in the right lateral portion of the intraparietal sulcus; an area well-known for perceptual processing of numerosity. The applied retro-cue design dissociated working memory delay activity from perceptual processes and showed that the intraparietal sulcus also maintained working memory representation independent of perception.

Action-Dependent Processing of Touch in the Human Parietal Operculum and Posterior Insula.

Somatosensory input generated by one's actions (i.e., self-initiated body movements) is generally attenuated. Conversely, externally caused somatosensory input is enhanced, for example, during active touch and the haptic exploration of objects. Here, we used functional magnetic resonance imaging (fMRI) to ask how the brain accomplishes this delicate weighting of self-generated versus externally caused somatosensory components. Finger movements were either self-generated by our participants or induced by functional electrical stimulation (FES) of the same muscles. During half of the trials, electrotactile impulses were administered when the (actively or passively) moving finger reached a predefined flexion threshold. fMRI revealed an interaction effect in the contralateral posterior insular cortex (pIC), which responded more strongly to touch during self-generated than during FES-induced movements. A network analysis via dynamic causal modeling revealed that connectivity from the secondary somatosensory cortex via the pIC to the supplementary motor area was generally attenuated during self-generated relative to FES-induced movements-yet specifically enhanced by touch received during self-generated, but not FES-induced movements. Together, these results suggest a crucial role of the parietal operculum and the posterior insula in differentiating self-generated from externally caused somatosensory information received from one's moving limb.

Intraparietal sulcus maintains working memory representations of somatosensory categories in an adaptive, context-dependent manner.

Working memory (WM) representations are generally known to be influenced by task demands, but it is not clear whether this extends to the somatosensory domain. One way to investigate the influence of task demands is with categorization paradigms, wherein either a single stimulus or an associated category is maintained in WM. In the somatosensory modality, category representations have been identified in the premotor cortex (PMC) and the intraparietal sulcus (IPS). In this study we used multivariate-pattern-analysis with human fMRI data to investigate whether the WM representations in the PMC, IPS or other regions are influenced by changing task demands. We ensured the task-dependent, categorical WM information was decorrelated from stimulus features by (1) teaching participants arbitrary, non-rule based stimulus groupings and (2) contrasting identical pairs of stimuli across experimental conditions, where either a single stimulus or the associated group was maintained in WM. Importantly, we also decoupled the decision and motor output from the WM representations. With these experimental manipulations, we were able to pinpoint stimulus-specific WM information to the left frontal and parietal cortices and context-dependent, group-specific WM information to the left IPS. By showing that grouped stimuli are represented more similarly in the Group condition than in the Stimulus condition, free from stimulus and motor output confounds, we provide novel evidence for the adaptive nature of somatosensory WM representations in the IPS with changing task-demands.

Neuronal signatures of a random-dot motion comparison task.

The study of perceptual decision making has made significant progress owing to major contributions from two experimental paradigms: the sequential vibrotactile frequency comparison task for the somatosensory domain requiring working memory, and the random-dot motion task in the visual domain requiring evidence accumulation over time. On the one hand, electrophysiological recordings in nonhuman primates and humans have identified changes in firing rates and power modulations of beta band oscillations with the vibrotactile frequencies held in working memory, as well as with the mental operation required for decision making. On the other hand, firing rates and centro-parietal potentials were found to increase to a fixed level at the time of responding during the random-dot motion task, possibly reflecting an underlying evidence accumulation mechanism until a decision threshold is met. Here, to bridge these two paradigms, we presented two visual random-dot motion stimuli in a sequential comparison task while recording EEG from human volunteers. We identified a modulation of prefrontal beta band power that scaled with the level of dot motion coherence of the first stimulus during a short retention interval. Furthermore, beta power in premotor areas was modulated by participants' choices approximately 700 ms before responses were given via button press. At the same time, dot motion patches of the second stimulus evoked a pattern of broadband centro-parietal signal build-up till responses were made, whose peak varied with trial difficulty. Hence, we show that known modulations of beta power during working memory and decision making extend from the vibrotactile to the visual domain and provide support for the notion of evidence accumulation as an unconfined decision-making mechanism generalizing over distinct decision types.

Centro-parietal EEG potentials index subjective evidence and confidence during perceptual decision making.

Recent studies suggest that a centro-parietal positivity (CPP) in the EEG signal tracks the absolute (unsigned) strength of accumulated evidence for choices that require the integration of noisy sensory input. Here, we investigated whether the CPP might also reflect the evidence for decisions based on a quantitative comparison between two sequentially presented stimuli (a signed quantity). We recorded EEG while participants decided whether the latter of two vibrotactile frequencies was higher or lower than the former in six variants of this task (n = 116). To account for biases in sequential comparisons, we applied a behavioral model based on Bayesian inference that estimated subjectively perceived frequency differences. Immediately after the second stimulus, parietal ERPs reflected the signed value of subjectively perceived differences and afterwards their absolute value. Strikingly, the modulation by signed difference was evident in trials without any objective evidence for either choice and correlated with choice-selective premotor beta band amplitudes. Modulations by the absolute strength of subjectively perceived evidence - a direct indicator of task difficulty - exhibited all features of statistical decision confidence. Together, our data suggest that parietal EEG signals first index subjective evidence, and later include a measure of confidence in the context of perceptual decision making.

Decoding vibrotactile choice independent of stimulus order and saccade selection during sequential comparisons.

Decision-making in the somatosensory domain has been intensively studied using vibrotactile frequency discrimination tasks. Results from human and monkey electrophysiological studies from this line of research suggest that perceptual choices are encoded within a sensorimotor network. These findings, however, rely on experimental settings in which perceptual choices are inextricably linked to sensory and motor components of the task. Here, we devised a novel version of the vibrotactile frequency discrimination task with saccade responses which has the crucial advantage of decoupling perceptual choices from sensory and motor processes. We recorded human fMRI data from 32 participants while they performed the task. Using a whole-brain searchlight multivariate classification technique, we identify the left lateral prefrontal cortex and the oculomotor system, including the bilateral frontal eye fields (FEF) and intraparietal sulci, as representing vibrotactile choices. Moreover, we show that the decoding accuracy of choice information in the right FEF correlates with behavioral performance. Not only are these findings in remarkable agreement with previous work, they also provide novel fMRI evidence for choice coding in human oculomotor regions, which is not limited to saccadic decisions, but pertains to contexts where choices are made in a more abstract form.

Content-Specific Codes of Parametric Vibrotactile Working Memory in Humans.

To understand how the brain handles mentally represented information flexibly in the absence of sensory stimulation, working memory (WM) studies have been essential. A seminal finding in monkey research is that neurons in the prefrontal cortex (PFC) retain stimulus-specific information when vibrotactile frequencies were memorized. A direct mapping between monkey studies and human research is still controversial. Although oscillatory signatures, in terms of frequency-dependent parametric beta-band modulation, have been observed recently in human EEG studies, the content specificity of these representations in terms of multivariate pattern analysis has not yet been shown. Here, we used fMRI in combination with multivariate classification techniques to determine which brain regions retain information during WM. In a retro-cue delayed-match-to-sample task, human subjects memorized the frequency of vibrotactile stimulation over a 12 s delay phase. Using an assumption-free whole-brain searchlight approach, we tested with support vector regression which brain regions exhibited multivariate parametric WM codes of the maintained frequencies during the WM delay. Interestingly, our analysis revealed an overlap with regions previously identified in monkeys composed of bilateral premotor cortices, supplementary motor area, and the right inferior frontal gyrus as part of the PFC. Therefore, our results establish a link between the WM codes found in monkeys and those in humans and emphasize the importance of the PFC for information maintenance during WM also in humans.SIGNIFICANCE STATEMENT Working memory (WM) research in monkeys has identified a network of regions, including prefrontal regions, to code stimulus-specific information when vibrotactile frequencies are memorized. Here, we performed an fMRI study during which human subjects had to memorize vibratory frequencies in parallel to previous monkey research. Using an assumption-free, whole-brain searchlight decoding approach, we identified for the first time regions in the human brain that exhibit multivariate patterns of activity to code the vibratory frequency parametrically during WM. Our results parallel previous monkey findings and show that the supplementary motor area, premotor, and the right prefrontal cortex are involved in vibrotactile WM coding in humans.

Brain regions that retain the spatial layout of tactile stimuli during working memory - A 'tactospatial sketchpad'?

Working memory (WM) studies have been essential for ascertaining how the brain flexibly handles mentally represented information in the absence of sensory stimulation. Most studies on the memory of sensory stimulus features have focused, however, on the visual domain. Here, we report a human WM study in the tactile modality where participants had to memorize the spatial layout of patterned Braille-like stimuli presented to the index finger. We used a whole-brain searchlight approach in combination with multi-voxel pattern analysis (MVPA) to investigate tactile WM representations without a priori assumptions about which brain regions code tactospatial information. Our analysis revealed that posterior and parietal cortices, as well as premotor regions, retained information across the twelve-second delay phase. Interestingly, parts of this brain network were previously shown to also contain information of visuospatial WM. Also, by specifically testing somatosensory regions for WM representations, we observed content-specific activation patterns in primary somatosensory cortex (SI). Our findings demonstrate that tactile WM depends on a distributed network of brain regions in analogy to the representation of visuospatial information.

Content-specific codes of parametric auditory working memory in humans.

Brain activity in frontal regions has been found to represent frequency information with a parametric code during working memory delay phases. The mental representation of frequencies has furthermore been shown to be modality independent in non-human primate electrophysiology and human EEG studies, suggesting frontal regions encoding quantitative information in a supramodal manner. A recent fMRI study using multivariate pattern analysis (MVPA) supports an overlapping multimodal network for the maintenance of visual and tactile frequency information over frontal and parietal brain regions. The present study extends the investigation of working memory representation of frequency information to the auditory domain. To this aim, we used MVPA on fMRI data recorded during an auditory frequency maintenance task. A support vector regression analysis revealed working memory information in auditory association areas and, consistent with earlier findings of parametric working memory, in a frontoparietal network. A direct comparison to an analogous dataset of vibrotactile parametric working memory revealed an overlap of information coding in prefrontal regions, particularly in the right inferior frontal gyrus. Therefore, our findings indicate that the prefrontal cortex represents frequency-specific working memory content irrespective of the modality as has been now also revealed for the auditory modality.

Overlapping frontoparietal networks for tactile and visual parametric working memory representations.

Previous working memory (WM) research based on non-human primate electrophysiology and human EEG has shown that frontal brain regions maintain frequencies of flutter stimulation across different sensory modalities by means of a supramodal parametric WM code. These findings imply that frontal regions encode the memorized frequencies in a sensory-unspecific, quantitative format. Here, we explored which brain regions maintain information about frequencies provided by different sensory modalities at the level of activity pattern across fMRI voxel populations. Moreover, we sought evidence for a supramodal multivariate WM representation. Participants maintained the same set of frequencies of tactile vibration and visual flicker for a 6 s WM delay in a frequency discrimination task. A support vector regression model for multivariate pattern analysis was applied. We observed that sensory cortices were only selective for memoranda of their corresponding modalities, while frontoparietal regions exhibited distinguishable activity patterns to memorized frequencies regardless of sensory modality. A common multivariate code was not evident in our data. Collectively, we show that mnemonic representations for stimulus frequencies are maintained throughout the cortical hierarchy, in line with the suggested transformation of information across different representational formats. Although evidence for a supramodal multivariate code is absent, our findings underpin the generalized role of the frontoparietal cortex for maintaining quantitative information across sensory modalities.

Effects of propofol anesthesia on the processing of noxious stimuli in the spinal cord and the brain.

Drug-induced unconsciousness is an essential component of general anesthesia, commonly attributed to attenuation of higher-order processing of external stimuli and a resulting loss of information integration capabilities of the brain. In this study, we investigated how the hypnotic drug propofol at doses comparable to those in clinical practice influences the processing of somatosensory stimuli in the spinal cord and in primary and higher-order cortices. Using nociceptive reflexes, somatosensory evoked potentials and functional magnet resonance imaging (fMRI), we found that propofol abolishes the processing of innocuous and moderate noxious stimuli at low to medium concentration levels, but that intense noxious stimuli evoked spinal and cerebral responses even during deep propofol anesthesia that caused profound electroencephalogram (EEG) burst suppression. While nociceptive reflexes and somatosensory potentials were affected only in a minor way by further increasing doses of propofol after the loss of consciousness, fMRI showed that increasing propofol concentration abolished processing of intense noxious stimuli in the insula and secondary somatosensory cortex and vastly increased processing in the frontal cortex. As the fMRI functional connectivity showed congruent changes with increasing doses of propofol - namely the temporal brain areas decreasing their connectivity with the bilateral pre-/postcentral gyri and the supplementary motor area, while connectivity of the latter with frontal areas is increased - we conclude that the changes in processing of noxious stimuli during propofol anesthesia might be related to changes in functional connectivity.

Different responses of the right superior temporal sulcus to visual movement feedback during self-generated vs. externally generated hand movements.

An important implication of several recent accounts of motor control is that sensory feedback from self-generated movements is relatively attenuated based on predictions issued by the agent's motor system. Such a relative attenuation of sensory information during actions has already been demonstrated in the somatosensory domain. Here, we used functional magnetic resonance imaging (fMRI) and a virtual reality-based setup to investigate a potential attenuation of brain responses to realistic visual movement feedback during active vs. passive right-hand movements. The participants' right unseen hand was rotated either by the participants themselves or by the experimenter, while the participants received visual movement feedback via a photorealistic virtual 3D hand driven by their real hand movements, or received no visual feedback. We observed a significant interaction between movement type (active vs. passive) and movement feedback (vision vs. no vision) in the right superior temporal sulcus (STS), which showed relatively attenuated blood-oxygen-level-dependent (BOLD) signal differences in movements with vs. without visual feedback when those movements were actively vs. passively executed. This finding suggests that STS activity caused by visual feedback from the moving body may be attenuated based on the agent's motor predictions.

Oscillatory EEG signatures of postponed somatosensory decisions.

In recent electroencephalography (EEG) studies, the vibrotactile frequency comparison task has been used to study oscillatory signatures of perceptual decision making in humans, revealing a choice-selective modulation of premotor upper beta band power shortly before decisions were reported. Importantly, these studies focused on decisions that were (1) indicated immediately after stimulus presentation, and (2) for which a direct motor mapping was provided. Here, we investigated whether the putative beta band choice signal also extends to postponed decisions, and how such a decision signal might be influenced by a response mapping that is dissociated from a specific motor command. We recorded EEG data in two separate experiments, both employing the vibrotactile frequency comparison task with delayed decision reports. In the first experiment, delayed choices were associated with a fixed motor mapping, whereas in the second experiment, choices were mapped onto a color code concealing a specific motor response until the end of the delay phase. In between stimulus presentations, as well as after the second stimulus, prefrontal beta band power indexed stimulus information held in working memory. Beta band power also encoded choices during the response delay, notably, in different cortical areas depending on the provided response mapping. In particular, when decisions were associated with a specific motor mapping, choices were represented in premotor cortices, whereas the color mapping resulted in a choice-selective modulation of beta band power in parietal cortices. Together, our findings imply that how a choice is expressed (i.e., the decision consequence) determines where in the cortical sensorimotor hierarchy an according decision signal is processed.