Biology subjects

Grahn, J.

Publications and source records attributed to Grahn, J..

2 recordsLinked to original sources

bioRxiv2024

Auditory working memory mediates the relationship between musicianship and auditory stream segregation

This study investigates the interactions between musicianship and two auditory cognitive mechanisms: auditory working memory (AWM) and stream segregation. The primary hypothesis is that AWM mediates the relationship between musical training and enhanced stream segregation capabilities. Two groups of listeners were tested, the first to establish the relationship between the two variables and the second to replicate the effect in an independent sample. Music history and behavioural data were collected from a total of 145 healthy young adults with normal binaural hearing. They performed a task that requires manipulation of tonal patterns in working memory, and the Music-in-Noise Task (MINT), which measures stream segregation abilities in a musical context. The MINT task expands measurements beyond traditional Speech-in-Noise (SIN) assessments by capturing auditory subskills (e.g., rhythm, visual, spatial, prediction) relevant to stream segregation. Our results showed that musical training is associated with enhanced AWM and MINT task performance, and that this effect is replicable across independent samples. Moreover, we found in both samples that the enhancement of stream segregation was largely mediated by AWM capacity. The results suggest that musical training and/or aptitude enhances music-in-noise perception by way of improved AWM capacity.

neuroscience↗

bioRxiv2021

Supplementary motor area contributions to rhythm perception

Timing is everything, but our understanding of the neural mechanisms of timing remains limited, particularly for timing of sequences. Temporal sequences can be represented relative to a recurrent beat (beat-based or relative timing), or as a series of absolute durations (non-beat-based or absolute timing). Neuroimaging work suggests involvement of the basal ganglia, supplementary motor area (SMA), the premotor cortices, and the cerebellum in both beat- and non-beat-based timing. Here we examined how beat-based timing and non-beat-based sequence timing were affected by modulating excitability of the supplementary motor area, the right cerebellum, and the bilateral dorsal premotor cortices, using transcranial direct current stimulation (tDCS). Participants were subjected to a sham stimulation session, followed an active stimulation session where anodal or cathodal 2mA tDCS was applied to the SMA, right premotor cortex, left premotor cortex, or the cerebellum. During both sessions, participants discriminated changes in rhythms which differentially engage beat-based or non-beat-based timing. Rhythm discrimination performance was improved by increasing SMA excitability, and impaired by decreasing SMA excitability. This polarity-dependent effect on rhythm discrimination was absent for cerebellar or premotor cortex stimulation, suggesting a crucial role of the SMA and/or its functionally connected networks in rhythmic timing mechanisms.

neuroscience↗