Biology subjects

Mukamel, R.

Publications and source records attributed to Mukamel, R..

8 recordsLinked to original sources

bioRxiv2025

Expectations and Motor Signals Shape Auditory Evoked Responses in an Independent Manner

Voluntary actions are usually accompanied by sensory consequences that evoke neural responses in relevant sensory regions. These evoked responses are different when compared to those evoked by otherwise identical physical stimulation not associated with preceding actions (sensory attenuation). A common model suggests that sensory attenuations are caused by efference signals associated with the binding of actions with sensory outcomes. Nevertheless, the information encoded in such signals is debated, with some theories suggesting they convey predictive information while others suggest they convey global motor information regardless of specific outcome expectations. To address this debate, we recorded EEG data while participants (n=30) learned to associate motor or visual cues with corresponding tones. Following 8 repetitions of cue-tone learning, participants successfully learnt the association (>84% correct). At the neural level, the amplitude of auditory evoked responses (N100) decreased across repetitions, as the binding between cues and tones strengthened. In addition, N100 amplitude was attenuated when preceded by motor vs, visual cues. Most importantly, we did not find an interaction effect between repetition and cue type, suggesting a similar sensory attenuation effect across repetitions. Specifically, we show significant sensory attenuation even at the first repetition, when no expectation could be formed. Thus, our results suggest that the sensory attenuation effect does not change while forming experience with action-outcome contingency. These results have implications for contemporary models of sensorimotor control and predictive mechanisms.

neuroscience↗

bioRxiv2024

High or Low Expectations: Expected intensity of action outcome is embedded in action ‎kinetics

Goal-directed actions are performed in order to attain certain sensory consequences in the world. However, expected attributes of these consequences can affect the kinetics of the action. In a set of three studies (n=120), we examined how expected attributes of stimulus outcome (intensity) shape the kinetics of the triggering action (applied force), even when the action and attribute are independent. We show that during action execution (button presses), the expected intensity of sensory outcome implicitly affects the applied force of the stimulus-producing action in an inverse fashion. Thus, participants applied more force when the expected intensity of the outcome was low (vs. high intensity outcome). In the absence of expectations or when actions were performed in response to the sensory event, no intensity-dependent force modulations were found. Thus, causality and expectations of stimulus intensity play an important role in shaping action kinetics. Finally, we examined the relationship between kinetics and perception and found no influence of applied force level on perceptual detection of low intensity (near-threshold) outcome stimuli, suggesting no causal link between the two. Taken together, our results demonstrate that action kinetics are implicitly embedded with high-level context such as the expectation of consequence intensity and the causal relationship with environmental cues.

neuroscience↗

bioRxiv2021

Same Action, Different Meaning: Neural substrates of Semantic Goal Representation

Accurate control over everyday goal-directed actions is mediated by sensory-motor predictions of intended consequences and their comparison with actual outcomes. Such online comparisons of the expected and re-afferent, immediate, sensory feedback are conceptualized as internal forward models. Current predictive coding theories describing such models typically address the processing of immediate sensory-motor goals, yet voluntary actions are also oriented towards long-term conceptual goals and intentions, for which the sensory consequence is sometimes absent or cannot be fully predicted. Thus, the neural mechanisms underlying actions with distal conceptual goals is far from being clear. Specifically, it is still unknown whether sensory-motor circuits also encode information regarding the global meaning of the action, detached from the immediate, movement-related goal. Therefore, using fMRI and behavioral measures, we examined identical actions (either right or left-hand button presses) performed for two different semantic intentions ( yes/ no response to questions regarding visual stimuli). Importantly, actions were devoid of differences in the immediate sensory outcome. Our findings revealed voxel patterns differentiating the two semantic goals in the frontoparietal cortex and visual pathways including the Lateral-occipital complex, in both hemispheres. Behavioral results suggest that the results cannot be explained by kinetic differences such as force. To the best of our knowledge, this is the first evidence showing that semantic meaning is embedded in the neural representation of actions independent of immediate sensory outcome and kinetic differences. Significance statementA standing question in neuroscience concerns the nature of neural circuits representing conceptual information. Previous studies indicate that regions traditionally associated with movement kinematics, also encode symbolic action categories regardless of their specific motor scheme. However, it is currently unclear whether these sensory-motor circuits also play a role in the representation of the intention, for which an action was initiated. Our results demonstrate that an actions intention, such as its semantic goal, can be discriminated based on neural activity patterns in motor and sensory regions. Moreover, our findings suggest that semantic goals are embedded in sensorimotor regions in a hand-dependent manner.

neuroscience↗

bioRxiv2020

Motor-evoked neural responses in auditory cortex are associated with improved sensitivity to self-generated sounds

Sensory perception is a product of complex interactions between the internal state of an organism and the physical attributes of a stimulus. One factor that modulates the internal state of the perceiving agent is voluntary movement. It has been shown across the animal kingdom that perception and sensory-evoked physiological responses are modulated depending on whether or not the stimulus is the consequence of voluntary actions. These phenomena are often attributed to motor signals sent to relevant sensory regions (efference copies), that convey information about expected upcoming sensory consequences. However, to date, there is no direct evidence in humans for efferent signals underlying these motor-sensory interactions. In the current study we recorded neurophysiological (using Magnetoencephalography) and behavioral responses from 16 healthy subjects performing an auditory detection task of faint tones. Tones were either generated by subjects voluntary button presses or occurred predictably following a visual cue. By introducing a constant temporal delay between button press/cue and tone delivery and applying source-level analysis we decoupled motor-evoked and auditory-evoked activity in auditory cortex. We show motor-related evoked-responses in auditory cortex following sound-triggering actions and preceding sound onset. Such evoked-responses were not found for button-presses that were not coupled with expected sounds. Furthermore, the amplitude of these evoked-responses corresponded with subsequent sound detection, suggesting their functional relevance to auditory processing. Our results provide first direct evidence for efferent signals in sensory cortex that are evoked by voluntary actions coupled with sensory consequences.

neuroscience↗

bioRxiv2020

Voluntary actions modulate perception and neural representation of action-consequences in a hand-dependent manner

Evoked neural activity in sensory regions, and perception of sensory stimuli, are modulated when the stimuli are the consequence of voluntary movement as opposed to an external source. It has been suggested that such modulations are due to efference copies of the motor command that are sent to relevant sensory regions during voluntary movement. Given the anatomical-functional laterality bias of the motor system, it is plausible that the pattern of such behavioral and neural sensory modulations will exhibit a similar bias, depending on the effector that was used to trigger the stimulus (e.g. right / left hand). Here we examined this issue in the visual domain using behavioral and neural measures (fMRI). Healthy participants judged the relative brightness of identical visual stimuli that were either self-triggered (using right or left hand button presses), or triggered by the computer. By presenting stimuli to either the right or left visual field, we biased visual-evoked responses to left / right visual cortex. We found stronger perceptual modulations when the triggering hand was ipsi (rather than contra) lateral to the stimulated visual field. At the neural level, we found that despite identical physical properties of the visual consequence, evoked fMRI responses in right and left visual cortices differentiate the identity of the triggering hand (left / right). Our findings support a model in which voluntary actions induce sensory modulations that follow the anatomical-functional bias of the motor system.

neuroscience↗

bioRxiv2019

Single-cell activity in human STG during perception of phonemes is organized according to manner of articulation

A long-standing controversy persists in psycholinguistic research regarding the way phonemes are coded in human auditory cortex during speech perception. Whereas the motor theory of speech perception suggests that phonemes are organized in terms of common articulatory gestures that generate them, auditory theories argue that phonetic processing is organized based on common spectro-temporal patterns in phoneme waveforms. Here, we recorded spiking activity in the superior temporal gyrus (STG) from six neurosurgical patients who performed a listening task with phoneme stimuli. Using a Naive-Bayes model, we show that single-cell responses to phonemes are governed by articulatory features that have acoustic correlates (manner-of-articulation) and organized according to sonority, with two main clusters for sonorants and obstruents. We further find that neural similarity (i.e. the similarity of evoked spiking activity between pairs of phonemes), is comparable to the perceptual similarity (i.e. how much the pair of phonemes sound similar) based on perceptual confusion assessed behaviorally in healthy subjects. Thus phonemes that were perceptually similar, also had similar neural responses. Our findings establish that phonemes are encoded according to manner-of-articulation, supporting the auditory theories of perception, and that the perceptual representation of phonemes can be reflected by the activity of single neurons in STG.

neuroscience↗

bioRxiv2017

Using experimental data as a voucher for study pre-registration

Undisclosed exploitation of flexibility in data acquisition and analysis blurs the important distinction between exploratory and hypothesis-driven findings and inflates false-positive rates1-4. Indeed, recent replication attempts have revealed low levels of replicability, pointing to high rates of false-positives in the literature5-10. A contemporary solution to this problem is pre-registration: commitment to aspects of methods and analysis before data acquisition11. This solution is valid only to the extent that the commitment stage is time-locked to precede data collection. To date, time-locking can only be guaranteed by introducing a third party such as peer reviewers at an early stage, making this solution less appealing for many12. Here we adapt a cryptographic method13 to encode information of study protocol within random aspects of the data acquisition process. This way, the structure of variability in the data time-locks the commitment stage with respect to data acquisition. Being independent of any third party, this method fully preserves scientific autonomy and confidentiality. We provide code for easy implementation and a detailed example from the field of functional Magnetic Resonance Imaging (fMRI).

scientific communication and education↗

bioRxiv2017

Predicted sensory consequences of voluntary actions modulate amplitude and temporal dynamics of preceding readiness potentials

Self-generated, voluntary actions, are preceded by a slow negativity in the scalp electroencephalography (EEG) signal recorded from frontal regions (termed readiness potential; RP). This signal, and its lateralized subcomponent (LRP), is mainly regarded as preparatory motor activity associated with the forthcoming motor act. However, it is not clear whether this neural signature is associated with preparatory motor activity, expectation of its associated sensory consequences, or both. Here we recorded EEG data from 12 healthy subjects while they performed self-paced button presses with their right index and middle fingers. In one condition (motor+sound) these button-presses triggered a sound while in another (motor-only) they did not. Additionally, subjects passively listened to sounds delivered in expected timings (sound-only). We found that the RP amplitude (locked to time of button press) was significantly more negative in the motor+sound compared with motor-only conditions starting ~1.4 seconds prior to button press. Importantly, no signal negativity was observed prior to expected sound delivery in the sound-only condition. Thus, the differences in RP amplitude between motor+sound and motor-only conditions are beyond differences in mere expectation of a forthcoming auditory sound. No significant differences between the two conditions were obtained in the LRP component. Our results suggest that expected auditory consequences are encoded in the early phase of the RP preceding the voluntary actions that generate them.

neuroscience↗