Biology subjects

Hoddinott, J. D.

Publications and source records attributed to Hoddinott, J. D..

4 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↗

bioRxiv2023

Investigating the Causal Role of Motor Brain Areas in Rhythm Reproduction: A Transcranial Direct Current Stimulation Study

Humans have an intrinsic tendency to move to music. However, our understanding of the neural mechanisms underlying the music-movement connection remains limited, and most studies have used correlational methods. Here, we used transcranial direct current stimulation (tDCS) to investigate the causal role of four brain regions commonly involved in movement timing and beat perception: the supplementary motor area (SMA), left and right premotor cortices (PMC), and the right cerebellum. On three different days, subjects received anodal, cathodal, or sham stimulation while reproducing strong-beat, weak-beat, and non-beat rhythms via finger tapping. Each subject only received stimulation in one of the four brain regions. As the SMA appears to play a primary role in beat perception, while the premotor cortex and cerebellum appear to have a more general role in timing, we predicted that the SMA stimulation would affect reproduction of rhythms with a beat, whereas premotor and cerebellar stimulation would affect reproduction of sequences with no beat. As expected, reproduction accuracy depended on beat strength; strong-beat rhythms were more accurately reproduced than weak and non-beat rhythms. Unexpectedly, tDCS had no effect on reproduction accuracy in any brain region. Thus, we found no evidence that modulating brain excitability in SMA, PMC, or cerebellum altered accuracy of rhythm reproduction. We discuss the implications of these results and future perspectives for this research.

neuroscience↗

bioRxiv2023

Neural Representations of Beat and Rhythm in Motor and Association Regions

Humans perceive a pulse, or beat, underlying musical rhythm. Beat strength correlates with activity in the basal ganglia and SMA, suggesting these regions support beat perception. However, the basal ganglia and SMA make up a general timing network active during rhythm and timing perception, regardless of beat. Therefore, activity in these regions may represent basic rhythmic features, in addition to beat. Using RSA, we characterized the neural representation of rhythm in the basal ganglia, SMA, and across the whole brain. During fMRI, participants heard 12 rhythms - 4 strong-beat, 4 weak-beat, and 4 non-beat. Multi-voxel activity patterns for each rhythm, and for the mean of each condition, were tested for uniqueness. Activity patterns in beat-sensitive regions should alter as a function of beat strength, eliciting greater dissimilarities between rhythms with different beat strength than between rhythms with similar beat strength. Indeed, mean activity patterns in the putamen and SMA were significantly dissimilar for strong-beat and non-beat conditions, and dissimilarity between activity patterns across all 12 rhythms correlated with beat strength models, not basic rhythmic features. Whole-brain analyses also identified beat-sensitivity in the IFG, and inferior parietal cortex. These findings build upon univariate work suggesting that motor and association regions are beat-sensitive.

neuroscience↗

bioRxiv2019

Investigation of working memory networks for verbal and rhythmic stimuli

Auditory working memory is often conceived of as a unitary capacity, with memory for different auditory materials (syllables, pitches, rhythms) thought to rely on similar neural mechanisms. One spontaneous behavior observed in working memory studies is chunking. For example, individuals often recount digit sequences in groups, or chunks, of 3 to 4 digits, and this chunking improves performance. Chunking may also operate in musical rhythm, with beats acting as chunk boundaries for tones in rhythmic sequences. Similar to chunking, beat-based structure in rhythms also improves performance. Thus, beat processing may rely on the same mechanisms that underlie chunking of verbal material. The current fMRI study examined whether beat perception is a type of chunking, measuring brain responses to chunked and unchunked letter sequences relative to beat-based and nonbeat-based rhythmic sequences. Participants completed a sequence discrimination task, and comparisons between stimulus encoding, maintenance, and discrimination were made for both rhythmic and verbal sequences. Overall, rhythm and verbal working memory networks overlapped substantially. When comparing rhythmic and verbal conditions, rhythms activated basal ganglia, supplementary motor area, and anterior insula, compared to letter strings, during encoding and discrimination. Letter strings compared to rhythms activated bilateral auditory cortex during encoding, and parietal cortex, precuneus, and middle frontal gyri during discrimination. Importantly, there was a significant interaction in the basal ganglia during encoding: activation for beat-based rhythms was greater than for nonbeat-based rhythms, but verbal chunked and unchunked conditions did not differ. The significant interaction indicates that beat perception is not simply a case of chunking, suggesting a dissociation between beat processing and grouping mechanisms that warrants further exploration.

neuroscience↗