What are the neurophysiological correlates of paired associative stimulation (PAS) in inducing plastic changes in human motor cortex (M1)? Here, Arrigoni and colleagues (2024) will apply transcranial magnetic stimulation (TMS) to left M1 paired with electrical stimulation of the right median nerve at an ISI of 25 ms or 10 ms to induce long-term potentiation (LTP) or long-term depression (LTD), respectively. Arrigoni and colleagues (2024) will determine if these stimulation pairings effect cortical excitability using motor-evoked potentials (MEPs) and TMS-evoked potentials (TEPs). Specifically, they hypothesize PASLTP will increase the peak-to-peak amplitude of MEPs, whereas PASLTD will decrease the amplitude, replicating previous work. They will then extend these previous findings by examining TEPs. The authors anticipate modulation of the P30 and P60, which are TEPs thought to reflect local cortical excitability. They plan to account for the MEP reafference which may also mediate the P60 amplitude by stimulating at sub- and supra- motor threshold. Further, they hypothesize an increase of the N100, a marker of inhibitory processing mediated by GABA, by PASLTD. Finally, the authors will also examine the impact of cortical excitability over time to determine the duration of the PAS effects.   

 

This detailed examination of TEPs following PAS stimulation will determine which TEPs could be used as biomarkers with the induction of LTP and LTD through stimulation. The authors have built in an MEP replication for the PAS stimulation, supporting previous literature and acting as a positive control.  

 

The Stage 1 manuscript was evaluated by three expert reviewers across two rounds. Following in-depth review and responses from the authors, the recommender determined that Stage 1 criteria was met and awarded in-principle acceptance (IPA).

 

URL to the preregistered Stage 1 protocol: https://osf.io/detjc (under temporary private embargo)
 
Level of bias control achieved: Level 6. No part of the data or evidence that will be used to answer the research question yet exists and no part will be generated until after IPA. 
 
List of eligible PCI RR-friendly journals:

 

References
 
1. Arrigoni, E., Bolognini, N., Pisoni, A. & Guidali, G. (2024). Neurophysiological correlates of plasticity induced by paired associative stimulation (PAS) targeting the motor cortex: a TMS-EEG registered report. In principle acceptance of Version 3 by Peer Community in Registered Reports. https://osf.io/detjc

One of the hallmarks of cognitive control is the ability to flexibly update attention and action when goals change. The prefrontal cortex has long been identified as important for such updating, but much remains to be understood about the anatomical and temporal mechanisms that support cognitive flexibility within prefrontal networks. In the current study, Jackson et al. (2024) build upon insights from recent transcranial magnetic stimulation (TMS) and neuroimaging studies to investigate the critical role of prefrontal cortex for updating goals and selecting behaviourally-relevant stimuli.

 

To measure updating, the authors deploy an attentional switching paradigm in which participants selectively attend to one feature of a novel object (colour or form) while ignoring the other feature. On each trial, a symbol (called a rule cue) indicates whether to attend to the colour (green or blue) or to the form (X or non-X) of the upcoming object. By mapping each stimulus response to a separate button press (two buttons for the two colours; two buttons for the two features), the authors can then categorise different types of behavioural errors – focusing especially on attending incorrectly to the task-irrelevant feature (rule error) vs. applying the correct rule but failing to correctly identify the task-relevant feature (stimulus error). If disruption of a specific cortical region causes a selective increase in one type of error, then this would indicate that the stimulated region is important for either rule processing or stimulus processing.

 

The proposal includes a number of key features that add depth and rigor to the investigation. First, to probe the anatomical specificity of cognitive control, the authors will contrast the effect of TMS delivered to different prefrontal regions that reside within different networks and may have divergent roles in cognitive control: the dorsolateral prefrontal cortex (dlPFC, part of the multiple-demand network) and dorsomedial prefrontal cortex (dmPFC, part of the default mode network). Moreover, unlike many previous TMS studies, the authors will use electric field modelling to normalise cortical stimulation strength between regions, enabling a more controlled anatomical comparison. Second, since the task involves responding to a rule cue and then selectively attending to a task-relevant feature, it is likely that a particular brain region could be selectively critical at a specific time – for instance, if dlPFC were important for rule processing then it should only be necessary shortly after (or around) presentation of the rule cue. To capture the temporal specificity of cortical involvement, the authors will apply a short burst of TMS at different times, beginning either +150ms after the cue or +700ms during stimulus processing. In a preliminary study, the authors used magnetoencephalography (MEG) in combination with the same behavioural task and multivariate pattern analysis (MVPA) to identify these epochs for TMS. Finally, the experiment includes a range of additional control conditions and quality checks to rule out alternative explanations of potential findings, such as TMS impairing perception of the rule cue rather than implementation of the rule, and the effect of peripheral TMS artefacts. Overall, the study promises to reveal a range of intriguing new insights into the timecourse and anatomical specificity of cognitive updating, with implications for theories of prefrontal cortical function.

 

The Stage 1 manuscript was evaluated over one round of in-depth review. Based on detailed responses to the reviewers' and recommender’s comments, the recommender judged that the manuscript met the Stage 1 criteria and therefore awarded in-principle acceptance (IPA).

 

URL to the preregistered Stage 1 protocol: https://osf.io/7pxjz (under temporary private embargo)

 

Level of bias control achieved: Level 6. No part of the data or evidence that will be used to answer the research question yet exists and no part will be generated until after IPA.

 
List of eligible PCI RR-friendly journals:

 

 

 

Jackon, J. B, Runhao, L., & Woolgar, A. (2024). Causal dynamics of task-relevant rule and stimulus processing in prefrontal cortex. In principle acceptance of Version 2 by Peer Community in Registered Reports. https://osf.io/7pxjz

The interplay of music, movement, and cultural experience shapes rhythm perception. From bouncing babies and children at play, to tapping, clapping, and dancing, music often triggers synchronous body movements that can influence how we process rhythm. And, at the same time, long-term exposure to specific musical traditions shapes how we perceive and interpret rhythms.

 

However, direct behavioural and neuroscientific evidence on how these processes occur remains scarce. In this programmatic submission, comprising two complementary Stage 2 reports, Guérin et al. (2024) will investigate how body movements shape the processing of auditory information, and how previous short-term motor practice and long-term cultural experience interact to shape neural and behavioural responses to rhythmic stimuli. The authors will record in separate sessions both  electroencephalography (EEG) and hand clapping, in response to rhythms from West/Central Africa. These recordings will be conducted before and after a session in which participants will clap/step to either a three or a four-beat metre that is expected to influence how they interpret a rhythm.

 

The first Stage 2 report, which will be conducted on African-enculturated participants, aims to demonstrate how body-movement pace flexibly imprints on human sensory processing. The authors build on various theoretical models that emphasise the role of motor production in metre perception, and predict that both neural and behavioural entrainment will improve following movement, matching the rhythmic pattern set by the previous body movements.

 

The second Stage 2 report aims to uncover how short-term motor practice and long-term cultural experience interact to shape responses to rhythmic stimuli, by integrating short-term motor practice and long-term cultural experience. For this, the authors will test separate groups of participants from distinct cultural backgrounds (African vs. Western-enculturated), which are predicted to show neural and behavioural differences in their preferred metric mapping before body movement, and expect that neural and behavioural entrainment will improve after movement, especially for the metre set by prior movements, and more significantly for the metre common in the participant's culture.

 

Together, the findings from the planned Stage 2 reports are expected to clarify how long-term cultural background and short-term motor practice imprint onto rhythm processing in humans. This research will enhance our understanding of how cultural experience, body movement, and neural plasticity interact in music processing.

 

The Stage 1 manuscript was evaluated over three rounds of in-depth review. Based on detailed responses to the reviewers' and recommender's comments, the recommender judged that the manuscript met the Stage 1 criteria and awarded in-principle acceptance (IPA).

 

URL to the preregistered Stage 1 protocol: https://osf.io/skuyc
 
Level of bias control achieved: Level 6. Data collection commenced during the later part of Stage 1 peer review; however, since no changes to the design were made after this point, the risk of bias due to prior data observation remains zero and the manuscript therefore qualifies for Level 6.
 
List of eligible PCI RR-friendly journals:

 

• Advances in Cognitive Psychology
• Brain and Neuroscience Advances
• Cortex
• Experimental Psychology
• Imaging Neuroscience
• In&Vertebrates
• NeuroImage: Reports
• Peer Community Journal
• PeerJ
• Psychology of Consciousness: Theory, Research, and Practice
• Royal Society Open Science
• Studia Psychologica
   

 

Guérin, S. M. R., Coulon, E., Lenc, T., Polak, R., Keller, P. E., & Nozaradan, S. (2024). Culture-Driven Neural Plasticity and Imprints of Body-Movement Pace on Musical Rhythm Processing. In principle acceptance of Version 2.1 by Peer Community in Registered Reports. https://osf.io/skuyc

Subjective tinnitus is a common disorder in which people experience a persistent sound in the absence of any external source. The underlying causes of tinnitus are debated – although the condition is strongly associated with hearing loss resulting from auditory damage, much remains to be understood about the neural processes that give rise to the phantom perception. Various classes of neurophysiological theories have been proposed, including the “altered gain” model – in which neurons in the auditory pathway increase their responsiveness to compensate for reduced auditory input following hearing loss – and the “noise cancellation” model – in which disrupted feedback connections from limbic regions are unable to tune out phantom signals. Although these theories account for much observed data, they have not been conclusively supported, and their ability to explain tinnitus is limited by the fact that hearing loss and tinnitus can arise independently and at different times.

 

In the current study, Reisinger et al. (2024) tested an emerging alternative theory based on a Bayesian predictive-coding framework (Sedley et al., 2016) in which the alteration of perceptual priors leads the auditory system to expect a sound that, if functioning normally, it should not expect. Using magnetoencephalography (MEG) in a sample of tinnitus patients (and carefully-matched controls for age, gender, and level of hearing loss), they asked whether tinnitus is associated with anticipatory brain activation, tuned to the carrier-frequency of an expected auditory stimulus. Specifically, the authors predicted that if the predictive-coding framework is correct then individuals with tinnitus should show different regularity-dependent pre-activations of carrier- frequency-specific information compared to the control group, while tone carrier-frequencies should be processed normally in tinnitus patients. They also predicted that any such pre-activations should not be related to levels of reported subjective tinnitus distress, as measured with the short version of the Tinnitus Questionnaire (mini-TQ).

 

The results broadly confirmed the hypotheses, with some caveats. Statistically significant differences in regularity-dependent pre-activations were observed between the tinnitus and control groups, however – curiously – the effects appear to be driven by below-chance decoding in the control group, complicating the interpretration. At the same time, consistent with expectations, frequency processing did not differ significantly between individuals with and without tinnitus, and the observed pre-activations were not significantly related to tinnitus distress. Overall, the findings cautiously support the conclusion that chronic tinnitus is associated with maladaptively upregulated predictive neural processing, and that this phenomenon is unlikely to be explained by either tinnitus distress or hearing loss.

 

The Stage 2 manuscript was evaluated over one round of in-depth review. Based on detailed responses to the reviewers' comments, the recommender judged that the manuscript met the Stage 2 criteria and awarded a positive recommendation.

 

 

Level of bias control achieved: Level 3. At least some data/evidence that was used to the answer the research question had been previously accessed by the authors (e.g. downloaded or otherwise received), but the authors certify that they had yet observed any part of the data/evidence prior to Stage 1 IPA.

 

 

• Brain and Neuroscience Advances
• Cortex
• F1000Research
• Imaging Neuroscience
• In&Vertebrates
• NeuroImage: Reports
• Peer Community Journal
• PeerJ
• Psychology of Consciousness: Theory, Research and Practice
• Royal Society Open Science

 

 

1. Reisinger, L., Demarchi, G., Rösch, , S., Trinka, E., Obleser, L., & Weisz, N. (2024). Registered Report: Are anticipatory auditory predictions enhanced in tinnitus and independent of hearing loss? [Stage 2] Acceptance of Version 3 by Peer Community in Registered Reports. https://osf.io/9wqjh

 

2. Sedley, W., Friston, K. J., Gander, P. E., Kumar, S., & Griffiths, T. D. (2016). An integrative tinnitus model based on sensory precision. Trends in Neurosciences, 39, 799-812. https://doi.org/10.1016/j.tins.2016.10.004

The enhanced processing account suggests that domain-specific expertise enhances the processing of information in that domain, such as enhanced color perception in visual artists and grapheme-color synaesthetes. A previous study (Ovalle-Fresa et al., 2021) found support for this account in both synaesthetes and non-synaesthete color experts; however, to fully understand the domain specificity of enhanced processing, other domains of expertise should be investigated and compared against each other in a double dissociation.

 

In this Stage 1 manuscript, Sachdeva et al. (2024) will investigate whether an enhanced processing account can explain domain-specific expertise in groups of color experts (i.e., visual artists) / grapheme-color synaesthetes and spatial experts (i.e., architects) / sequence-space synaesthetes. The spatial domain was chosen to compare to color since color and spatial processing recruit two distinctive cortical visual pathways: the ventral and dorsal streams, respectively. If enhanced processing is domain specific, then color experts / grapheme-color synaesthetes should show selective perceptual and memory performance enhancements for color tasks but not spatial tasks; and vice versa for spatial experts and sequence-space synaesthetes. The authors of this planned study further propose that perceptual performance should predict memory performance in the domain of expertise only; and that synaesthetes and non-synaesthetes with the same domain of expertise should perform similarly to each other.

 

To address these hypotheses, four independent groups will be recruited: grapheme-color synaesthetes, visual artists, sequence-space synaesthetes, and architects. Individuals with overlapping expertise and synaesthesia (e.g., visual artists who also have grapheme-color synaesthesia) will be excluded. Perception, short-term memory, and long-term memory for color (3 tasks) and space (3 tasks) will be assessed in all groups, and the authors will compare groups (synaesthetes, non-synaesthetes), domains of expertise (color, space), and task feature (color, space) in 2x2x2 linear mixed models. For all models, the authors predict that a significant interaction between domain of expertise and task feature will provide evidence for the domain specificity of the enhanced processing account. Additional analyses concerning working memory load (one, three, or five items) in the short-term memory tasks, and testing day (one, two, or three days post-training) in the long-term memory tasks, will be conducted to more deeply explore potential performance enhancements related to domain-specific expertise. Although these analyses may potentially provide additional evidence in favor of the hypothesized direction of effects, any deviation from predicted may pose a challenge for the interpretation of results. Nevertheless, this planned study is methodologically rigorous, and comprehensive in its aims.

 

The Stage 1 submission was evaluated by the recommender and two expert reviewers. Following revisions, the recommender judged that the manuscript met the Stage 1 criteria and awarded in-principle acceptance (IPA).

 

Level of bias control achieved: Level 6. No part of the data or evidence that will be used to answer the research question yet exists and no part will be generated until after IPA.
 
List of eligible PCI RR-friendly journals:
 

References
 

1. Ovalle-Fresa, R., Ankner, S., & Rothen, N. (2021). Enhanced perception and memory: Insights from synesthesia and expertise. Cortex, 140, 14-25. https://doi.org/10.1016/j.cortex.2021.01.024

2. Sachdeva, D. & Whelan, E., Ovalle-Fresa, R., Rey-Mermet, A., Ward, J., & Rothen, N.. (2024). How perceptual ability shapes memory: An investigation in healthy special populations. In principle acceptance of Version 2 by Peer Community in Registered Reports. https://osf.io/6wn4m