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Biology subjects

Herff, S. A.

Publications and source records attributed to Herff, S. A..

4 recordsLinked to original sources

Solitary Silence and Social Sounds: Music influences mental imagery, inducing thoughts of social interactions

The COVID-19 pandemic was accompanied by a marked increase in the use of music listening for self-regulation1. During these challenging times, listeners reported they used music to keep them company2; indicating that they may have turned to music for social solace3. However, whether this is simply a figure of speech or an empirically observable effect on social thought was previously unclear. In three experiments, six hundred participants were presented with silence or task-irrelevant music in Italian, Spanish, or Swedish while performing a directed mental-imagery task in which they imagined a journey towards a topographical landmark4. To control for a possible effect of vocals on imagined content, the music was presented with or without vocals to the participants, of which half were native speakers and the other half non-speakers of the respective languages. Music, compared to silence, led to more vivid imagination and changes in imagined content. Specifically, social interaction emerged as a clear thematic cluster in participants descriptions of their imagined content through Latent Dirichlet Allocation. Moreover, Bayesian Mixed effects models revealed that music significantly increased imagined social content compared to silence conditions. This effect remained robust irrespective of vocals or language comprehension. Using stable diffusion, we generated visualisations of participants imagined content. In a fourth experiment, a new group of participants was able to use these visualisations to differentiate between content imagined during music listening and that of the silence condition, but only when listening to the associated music. Results converge to show that music, indeed, can be good company.

animal behavior and cognition↗

Decoding Arbitrary and Informed Decisions from Intracranial Recordings in Humans

Ideally, decisions are made based on prior knowledge, which allows for informed choices. Real life, however, often requires us to make decisions arbitrarily, without sufficient information. Decoding decision making processes from neural activity could allow for cognitive neuroprostheses and Brain-Computer Interfaces (BCIs) to support decision processes in rapid human-machine interactions, weigh decision-making confidence, and further enable neuromodulation protocols for the treatment of reward-related dysfunctions. To understand the differences between the decision-making processes in arbitrary and informed decisions, we recorded intracranial electroencephalography in a large number of cortical and subcortical areas from 5 patients during a categorization task. We demonstrate that individual decisions can be decoded from Local Field Potentials (LFPs) before motor response, in both arbitrary and informed conditions. Our analysis revealed dissimilar spatio-temporal patterns between arbitrary and informed decision-making, with arbitrary decisions being decodable in fewer brain regions and earlier in time compared to informed decisions.

neuroscience↗

Hierarchical syntax models of music predict theta power during music listening

Linguistic research showed that the depth of syntactic embedding is reflected in brain theta power. Here, we test whether this also extends to non-linguistic stimuli, specifically music. We used a hierarchical model of musical syntax to continuously quantify two types of expert-annotated harmonic dependencies throughout a piece of Western classical music: prolongation and preparation. Prolongations can roughly be understood as a musical analogue to linguistic coordination between constituents that share the same function (e.g., pizza and pasta in I ate pizza and pasta). Preparation refers to the dependency between two harmonies whereby the first implies a resolution towards the second (e.g., dominant towards tonic; similar to how the adjective implies the presence of a noun in I like spicy...). Source reconstructed MEG data of sixty-eight participants listening to the musical piece was then analysed. We used Bayesian Mixed Effects models to predict theta envelope in the brain, using the number of open prolongation and preparation dependencies as predictors whilst controlling for audio envelope. We observed that prolongation and preparation both carry independent and distinguishable predictive value for theta band fluctuation in key linguistic areas such as the Angular, Supramarginal, Superior Temporal and Heschls Gyri, or their right-lateralised homologues, with preparation showing additional predictive value for areas associated with the reward system and prediction. Musical expertise further mediated these effects in language-related brain areas. Results show that predictions of precisely formalised music-theoretical models are reflected in the brain activity of listeners.

neuroscience↗

Prefrontal high-gamma in ECoG tags periodicity of musical rhythms in perception and imagination

Rhythmic auditory stimuli are known to elicit matching activity patterns in neural populations. Furthermore, recent research has established the particular importance of high-gamma brain activity in auditory processing by showing its involvement in auditory phrase segmentation and envelope-tracking. Here, we use electrocorticographic (ECoG) recordings from eight human listeners, to see whether periodicities in high-gamma activity track the periodicities in the envelope of musical rhythms during rhythm perception and imagination. Rhythm imagination was elicited by instructing participants to imagine the rhythm to continue during pauses of several repetitions. To identify electrodes whose periodicities in high-gamma activity track the periodicities in the musical rhythms, we compute the correlation between the autocorrelations (ACC) of both the musical rhythms and the neural signals. A condition in which participants listened to white noise was used to establish a baseline. High-gamma autocorrelations in auditory areas in the superior temporal gyrus and in frontal areas on both hemispheres significantly matched the autocorrelation of the musical rhythms. Overall, numerous significant electrodes are observed on the right hemisphere. Of particular interest is a large cluster of electrodes in the right prefrontal cortex that is active during both rhythm perception and imagination. This indicates conscious processing of the rhythms structure as opposed to mere auditory phenomena. The ACC approach clearly highlights that high-gamma activity measured from cortical electrodes tracks both attended and imagined rhythms.

neuroscience↗