Biology subjects

Matthews, T.

Publications and source records attributed to Matthews, T..

7 recordsLinked to original sources

bioRxiv2026

Universality Meets Cultural Nuances: Affective Responses to Rhythmic and Harmonic Complexity Across Cultures

The pleasurable urge to move to music - known as groove - has been linked to rhythmic and harmonic complexity via an inverted-U relationship, consistent with predictive coding theory of music. This link has been demonstrated mainly in Western listeners, leaving its cultural generality unclear. Given reports of heightened pitch and harmony sensitivity in Chinese listeners, we predicted stronger responses to harmonic complexity and weaker responses to rhythmic complexity compared with Western listeners. We conducted two online experiments measuring "pleasure" and "wanting to move" ratings for musical excerpts varying in rhythmic and harmonic complexity, comparing Chinese and Danish participants as representatives of Eastern and Western traditions. In Experiment 1, which manipulated both dimensions, both groups showed inverted-U responses to rhythmic complexity, but Danish participants exhibited a sharper curve, indicating greater affective differentiation. No inverted-U pattern emerged for harmonic complexity, and Chinese participants did not show enhanced harmonic sensitivity. Experiment 2 focused on rhythmic complexity using ecologically valid stimuli with finer gradations. Again, Danes showed greater sensitivity to rhythmic variation, reflected in a sharper curvature of their inverted U responses, though peak responses did not differ between groups. Our findings support the universality of predictive responses to rhythmic complexity, while highlighting the modulatory role of cultural exposure in shaping musical affective experiences.

neuroscience↗

bioRxiv2024

Behavioral Evidence for Two Modes of Attention

Attention modulates sensory gain to select and optimize the processing of behaviorally relevant events. It has been hypothesized that attention can operate in either a rhythmic or continuous mode, depending on the nature of sensory stimulation. Despite this conceptual framework, direct behavioral evidence has been scarce. Our study explores when attention operates in a rhythmic mode through a series of nine interrelated behavioral experiments with varying stream lengths, stimulus types, attended features, and tasks. The rhythmic mode optimally operates at approximately 1.5 Hz and is prevalent in perceptual tasks involving long (> 7 s) auditory streams. Our results are supported by a model of coupled oscillators, illustrating that variations in the systems noise level can induce shifts between continuous and rhythmic modes. Finally, the rhythmic mode is absent in syllable categorization tasks. Overall, this study provides empirical evidence for two modes of attention and defines their conditions of operation.

neuroscience↗

bioRxiv2022

Calculating functional diversity metrics using neighbor-joining trees

O_LIThe study of functional diversity (FD) provides ways to understand phenomena as complex as community assembly or the dynamics of biodiversity change under multiple pressures. Different frameworks are used to quantify FD, either based on dissimilarity matrices (e.g., Rao entropy, functional dendrograms) or multidimensional spaces (e.g. convex hulls, kernel-density hypervolumes). While the first does not enable the measurement of FD within a richness/divergence/regularity framework, or results in the distortion of the functional space, the latter does not allow for comparisons with phylogenetic diversity (PD) measures and can be extremely sensitive to outliers. C_LIO_LIWe propose the use of neighbor-joining trees (NJ) to represent and quantify functional diversity in a way that combines the strengths of current FD frameworks without many of their weaknesses. Our proposal is also uniquely suited for studies that compare FD with PD, as both share the use of trees (NJ or others) and the same mathematical principles. C_LIO_LIWe test the ability of this novel framework to represent the initial functional distances between species with minimal functional space distortion and sensitivity to outliers. The results using NJ are compared with conventional functional dendrograms, convex hulls, and kernel-density hypervolumes using both simulated and empirical datasets. C_LIO_LIUsing NJ we demonstrate that it is possible to combine much of the flexibility provided by multidimensional spaces with the simplicity of tree-based representations. Moreover, the method is directly comparable with PD measures, and enables quantification of the richness, divergence and regularity of the functional space. C_LI

ecology↗

bioRxiv2021

Land use, macroecology, and the accuracy of the Maximum Entropy Theory of Ecology: A case study of Azorean arthropods

Human activity and land management practices, in particular land use change, have resulted in the global loss of biodiversity. These types of disturbance affect the shape of macroecological patterns, and therefore analyzing these patterns can provide insights into how ecosystems are affected by land use change. We here use arthropod census data from 96 sites at Terceira Island in the Azores archipelago across four different land uses of increasing management intensity: native forest, exotic forest, semi-natural pasture, and intensive pasture, to examine the effects of land use type on three macroecological patterns: the species abundance distribution, the metabolic rate distribution of individuals, and the species-area relationship. The Maximum Entropy Theory of Ecology (METE) has successfully predicted these patterns across habitats and taxa in undisturbed ecosystems, and thus provides a null expectation for their shapes. Across these patterns, we find that the forest habitats are the best fit by METE predictions, while the semi-natural pasture is consistently the worst fit, and the intensive pasture is intermediately well fit. We show that the direction of failure of the METE predictions at the pasture sites is likely due to the hyper-dominance of introduced spider species present there. We hypothesize that the particularly poor fit for the semi-natural pasture is due to the mix of arthropod communities out of equilibrium, leading to greater heterogeneity in composition and complex dynamics that violate METEs assumption of static state variables. The comparative better fit for the intensive pasture plausibly results from more homogeneous arthropod communities that are well adapted to intensive management, and thus whose state variables are less in flux. Analyzing deviations from theoretical predictions across land use type provides useful information about how land use and disturbance affect ecosystems, and such comparisons could be useful across other habitats and taxa.

ecology↗

bioRxiv2019

11β-Hydroxysteroid Dehydrogenase Type 1 inhibition in Idiopathic Intracranial Hypertension: a double-blind randomized controlled trial.

Treatment options for idiopathic intracranial hypertension are limited. The enzyme 11{beta}-hydroxysteroid dehydrogenase type 1 has been implicated in regulating cerebrospinal fluid secretion, and its activity is associated with alterations in intracranial pressure in idiopathic intracranial hypertension. We assessed therapeutic efficacy, safety and tolerability, and investigate indicators of in vivo efficacy of the 11{beta}-hydroxysteroid dehydrogenase type 1 inhibitor AZD4017 compared to placebo in idiopathic intracranial hypertension. A multicenter, UK, 16-week phase II randomized, double-blind, placebo-controlled trial of 12-weeks treatment with AZD4017 or placebo was conducted. Women aged 18 to 55 years with active idiopathic intracranial hypertension (>25cmH2O lumbar puncture opening pressure and active papilledema) were included. Participants received 400mg twice daily of oral AZD4017 compared to matching placebo over 12-weeks. The outcome measures were initial efficacy, safety and tolerability. The primary clinical outcome was lumbar puncture opening pressure at 12 weeks analysed by intention-to-treat. Secondary clinical outcomes were symptoms, visual function, papilledema, headache and anthropological measures. In vivo efficacy was evaluated in the central nervous system and systemically. 31 subjects (mean age 31.2 (SD=6.9) years and BMI 39.2 (SD=12.6) kg/m2) were randomized to AZD4017 (n=17) or placebo (n=14). At 12 weeks, lumbar puncture pressure was lower in the AZD4017 group (29.7 cmH2O) compared with placebo (31.3 cmH2O), but the difference between groups was not statistically significant (mean difference: -2.8, 95% confidence interval: -7.1-1.5; p=0.2). An exploratory analysis assessing mean change in lumbar puncture pressure within each group found a significant decrease in the AZD4017 group (mean change: -4.3 cmH2O (SD=5.7); p=0.009) but not in the placebo group (mean change: -0.3 cmH2O (SD=5.9); p=0.8). AZD4017 was safe, with no withdrawals related to adverse effects. Nine transient drug-related adverse events were reported. One serious adverse event occurred in the placebo group (deterioration requiring shunt surgery). In vivo biomarkers of 11{beta}-hydroxysteroid dehydrogenase type 1 activity (urinary glucocorticoid metabolites, hepatic prednisolone generation and CSF cortisone to cortisol ratios) demonstrated significant enzyme inhibition. This is the first phase 2 randomized controlled trial in idiopathic intracranial hypertension evaluating a novel therapeutic target. AZD4017 was safe, well-tolerated and inhibited 11{beta}-hydroxysteroid dehydrogenase type 1 activity in vivo. Possible clinical benefits were noted in this small cohort. A longer, larger study would now be of interest.

clinical trials↗

bioRxiv2018

Using DNA from mothers and children to study parental investment in children’s educational attainment

This study tested implications of new genetic discoveries for understanding the association between parental investment and childrens educational attainment. A novel design matched genetic data from 860 British mothers and their children with home-visit measures of parenting: the E-Risk Study. Three findings emerged. First, both mothers and childrens education-associated genetics, summarized in a genome-wide polygenic score, predicted parenting -- a gene-environment correlation. Second, accounting for genetic influences slightly reduced associations between parenting and childrens attainment -- indicating some genetic confounding. Third, mothers genetics influenced childrens attainment over and above genetic mother-to-child transmission, via cognitively-stimulating parenting -- an environmentally-mediated effect. Findings imply that, when interpreting parents effects on children, environmentalists must consider genetic transmission, but geneticists must also consider environmental transmission.

genetics↗

bioRxiv2018

The sensation of groove is affected by the interaction of rhythmic and harmonic complexity

Groove is defined as the pleasurable desire to move to music. Research has shown that rhythmic complexity modulates the sensation of groove but how other musical features, such as harmony, influence groove is less clear. To address this, we asked people with a range of musical experience to rate stimuli that varied in both rhythmic and harmonic complexity. Rhythm showed an inverted U-shaped relationship with ratings of pleasure and wanting to move, whereas medium and low complexity chords were rated similarly. Pleasure mediated the effect of harmony on wanting to move and high complexity chords attenuated the effect of rhythm. While rhythmic complexity is the primary driver, harmony both modulates the effect of rhythm and makes a unique contribution via its effect on pleasure. These results may be accounted for by predictive processes based on rhythmic and harmonic expectancies that are known to contribute to musical pleasure or reward.

neuroscience↗