Authors:

GOCKEL, H.E., CARLYON, R.P.

Reference:

Year of publication:

2023

CBU number:

8921

Abstract:

Difference limens for fundamental frequency (F0), F0DLs, are usually small for complex tones containing low harmonics that are resolved in the auditory periphery, but worsen when the rank of the lowest harmonic increases above about 6–8 and harmonics become less resolved. The traditional explanation for this, in terms of resolvability, has been challenged and an alternative explanation in terms of harmonic rank was suggested. Here, to disentangle the effects of resolvability and harmonic rank the complex tones were presented either diotically (all harmonics to both ears) or dichotically (even and odd harmonics to opposite ears); the latter increases resolvability but does not affect harmonic rank. F0DLs were measured for 14 listeners for complex tones containing harmonics 6-10 with F0s of 280 and 1400 Hz, presented diotically or dichotically. For the low F0, F0DLs were significantly lower for the dichotic than for the diotic condition. This is consistent with a benefit of increased resolvability of harmonics for F0 discrimination and extends previous results to harmonics as low as the sixth. In contrast, for the high F0, F0DLs were similar for the two presentation modes, adding to evidence for differences in pitch perception between tones with low-to-medium and very-high frequency content.

URL:

Data available, click to request

Authors:

BRADSHAW, A.R., Lametti, D.R., Shiller, D.M., Jasmin, K., Huang., R., McGettigan, C.

Reference:

Year of publication:

In Press

CBU number:

8919

Abstract:

This paper was written in the authors previous workplace Sensorimotor integration during speech has been investigated by altering the sound of a speaker’s voice in real-time; in response, the speaker learns to change their production of speech sounds in order to compensate (adaptation). This line of research has however been predominantly limited to very simple speaking contexts, typically involving (1) repetitive production of single words and (2) production of speech whilst alone, without the usual exposure to other voices. This study investigated adaptation to a real-time perturbation of the first and second formants during production of sentences either in synchrony with a pre-recorded voice (synchronous speech group) or alone (solo speech group). Experiment 1 (n = 30) found no significant difference in the average magnitude of compensatory formant changes between the groups; however, synchronous speech resulted in increased between-individual variability in such formant changes. Participants also showed acoustic-phonetic convergence to the voice they were synchronising with prior to introduction of the feedback alteration. Furthermore, the extent to which the changes required for convergence agreed with those required for adaptation was positively correlated with the magnitude of subsequent adaptation. Experiment 2 tested an additional group with a metronome-timed speech task (n = 15), and found a similar pattern of increased between-participant variability in formant changes. These findings demonstrate that speech motor adaptation can be measured robustly at the group level during performance of more complex speaking tasks; however, further work is needed to resolve whether self-voice adaptation and other-voice convergence reflect additive or interactive effects during sensorimotor control of speech. https://osf.io/gz87s https://osf.io/q86cj

URL:

Data available, click to request

Authors:

ZDOROVTSOVA, N., JONES, J., AKARCA, D., BENHAMOU, E., The CALM Team, ASTLE, D.E.

Reference:

Year of publication:

2023

CBU number:

8918

Abstract:

Inattention and hyperactivity are cardinal symptoms of Attention Deficit Hyperactivity Disorder (ADHD). These characteristics have also been observed across a range of other neurodevelopmental conditions, such as autism and dyspraxia, suggesting that they might best be studied across diagnostic categories. Here, we evaluated the associations between inattention and hyperactivity behaviours and features of the structural brain network (connectome) in a large transdiagnostic sample of children (Centre for Attention, Learning, and Memory; n = 383). In our sample, we found that a single latent factor explains 77.6% of variance in scores across multiple questionnaires measuring inattention and hyperactivity. Partial Least-Squares (PLS) regression revealed that variability in this latent factor could not be explained by a linear component representing nodewise properties of connectomes. We then investigated the type and extent of neural heterogeneity in a subset of our sample with clinically-elevated levels of inattention and hyperactivity. Multidimensional scaling combined with k-means clustering revealed two neural subtypes in children with elevated levels of inattention and hyperactivity (n = 232), differentiated primarily by nodal communicability—a measure which demarcates the extent to which neural signals propagate through specific brain regions. These different clusters had similar behavioural profiles, which included high levels of inattention and hyperactivity. However, one of the clusters scored higher on multiple cognitive assessment measures of executive function. We conclude that inattention and hyperactivity are so common in children with neurodevelopmental difficulties because they emerge through multiple different trajectories of brain development. In our own data, we can identify two of these possible trajectories, which are reflected by measures of structural brain network topology and cognition.

URL:

Data available, click to request

Authors:

NORD, C.L., Longley, B., DERCON, Q., Phillips, V., Funk, J., GORMLEY, S., KNIGHT, R., SMITH, A.J. & DALGLEISH, T.

Reference:

Year of publication:

2023

CBU number:

8917

Abstract:

At least half of all patients with mental health disorders do not respond adequately to psychological therapy. Acutely enhancing particular biological or psychological processes during psychological therapy may improve treatment outcomes. However, previous studies are confined to specific augmentation approaches, typically assessed within single diagnostic categories. Our objective was to assess to what degree acute augmentations of psychological therapy reduce psychiatric symptoms and estimate effect sizes of augmentation types (for example, brain stimulation or psychedelics). We searched Medline, PsycINFO and Embase for controlled studies published between database inception and 25 May 2022. We conducted a preregistered random-effects meta-analysis (PROSPERO CRD42021236403). We identified 108 studies (N = 5,889). Acute augmentation significantly reduced the severity of mental health problems (Hedges’ g = −0.27, 95% CI: [−0.36, −0.18]; P < 0.0001), particularly for the transdiagnostic dimensions 'Fear' and 'Distress'. This result survived a trim-and-fill analysis to account for publication bias. Subgroup analyses revealed that pharmacological, psychological and somatic augmentations were effective, but to varying degrees. Acute augmentation approaches are a promising route to improve outcomes from psychological therapy.

URL:

Data available, click to request

Authors:

MOK, R.M., Love, B.C.

Reference:

Year of publication:

2023

CBU number:

8916

Abstract:

A complete neuroscience requires multi-level theories that address phenomena ranging from higher-level cognitive behaviors to activities within a cell. We propose an extension to the level-of-mechanisms approach where a computational model of cognition sits in between behavior and brain: it explains the higher-level behavior, and can be decomposed into lower-level component mechanisms to provide a richer understanding of the system than any level alone. Toward this end, we decomposed a cognitive model into neuron-like units using a neural flocking approach that parallels recurrent hippocampal activity. Neural flocking coordinates units that collectively form higher-level mental constructs. The decomposed model suggested how brain-scale neural populations coordinate to form assemblies encoding concept and spatial representations, and why so many neurons are needed for robust performance at the cognitive level. This multi-level explanation provides a way to understand how cognition and symbol-like representations are supported by coordinated neural populations (assemblies) formed through learning. Data and materials availability: Code and simulation results are available at Github (https://github.com/robmok/multiunit-cluster), Zenodo (https://zenodo.org/badge/latestdoi/308407059) and OSF (https://osf.io/uf8pa/). All data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials.

URL:

Data available, click to request

Authors:

Akkad, H., Hope, T.M.H., Howland, C., Ondobaka, S., Pappa, K., NARDO, D., DUNCAN, J., Leff, A.P., Crinion, J.2

Reference:

Year of publication:

2023

CBU number:

8915

Abstract:

Aphasia is an acquired disorder caused by damage, most commonly due to stroke, to brain regions involved in speech and language. While language impairment is the defining symptom of aphasia, the co-occurrence of non-language cognitive deficits and their importance in predicting rehabilitation and recovery outcomes is well documented. However, people with aphasia (PWA) are rarely tested on higher-order cognitive functions, making it difficult for studies to associate these functions with a consistent lesion correlate. Broca's area is a particular brain region of interest that has long been implicated in speech and language production. Contrary to classic models of speech and language, cumulative evidence shows that Broca's area and surrounding regions in the left inferior frontal cortex (LIFC) are involved in, but not specific to, speech production. In this study we aimed to explore the brain-behaviour relationships between tests of cognitive skill and language abilities in thirty-six adults with long-term speech production deficits caused by post-stroke aphasia. Our findings suggest that non-linguistic cognitive functions, namely executive functions and verbal working memory, explain more of the behavioural variance in PWA than classical language models imply. Additionally, lesions to the LIFC, including Broca's area, were associated with non-linguistic executive (dys)function, suggesting that lesions to this area are associated with non-language-specific higher-order cognitive deficits in aphasia. Whether executive (dys)function - and its neural correlate in Broca's area - contributes directly to PWA's language production deficits or simply co-occurs with it, adding to communication difficulties, remains unclear. These findings support contemporary models of speech production that place language processing within the context of domain-general perception, action and conceptual knowledge. An understanding of the covariance between language and non-language deficits and their underlying neural correlates will inform better targeted aphasia treatment and outcomes.

URL:

Data available, click to request

Authors:

MARSH, L.C., Patel, S.D., Smith, A.J., So, M., Armstrong, H., Elliott, R., Watkins, E., Moulds, M., DALGLEISH, T., Hitchcock, C.

Reference:

Year of publication:

2023

CBU number:

8914

Abstract:

Individuals with depression typically remember their past in a generalised manner, at the cost of retrieving specific event memories. This may impair engagement with cognitive behavioural therapy (CBT) tasks that use concrete episodic information to challenge maladaptive beliefs, potentially limiting their therapeutic benefit. Study 1 demonstrated that an episodic specificity induction increased detail and specificity of autobiographical memory in people with major depression, relative to control conditions (N = 88). We therefore examined whether the induction enhanced the efficacy of CBT tasks that depend on episodic memory – cognitive reappraisal (Study 2, N = 30), evidence gathering (Study 2, N = 30), and planning behavioural experiments (Study 3a, N = 30). Across all three tasks, there were no significant differences in emotion- or belief-change between the specificity and control conditions. Although the induction temporarily enhanced specificity in depressed individuals, it did not significantly augment the efficacy of CBT tasks theorised to benefit from the use of specific mnemonic information. https://osf.io/t6vx2/files/osfstorage

URL:

Data available, click to request

Authors:

Lee, Sung-Mu., Tibon, R., Zeidman, P., Yadav, P.S. and HENSON, R.

Reference:

Year of publication:

2023

CBU number:

8913

Abstract:

Stimulus repetition normally causes reduced neural activity in brain regions that process that stimulus. Some theories claim that this “repetition suppression” reflects local mechanisms such as neuronal fatigue or sharpening within a region, whereas other theories claim that it results from changed connectivity between regions, following changes in synchrony or top-down predictions. In this study, we applied dynamic causal modelling (DCM) on a public fMRI dataset involving repeated presentations of faces and scrambled faces to test whether repetition affected local (self-connections) and/or between-region connectivity in left and right early visual cortex (EVC), occipital face area (OFA) and fusiform face area (FFA). Face “perception” (faces versus scrambled faces) modulated nearly all connections, within and between regions, including direct connections from EVC to FFA, supporting a non-hierarchical view of face processing. Face “recognition” (familiar versus unfamiliar faces) modulated connections between EVC and OFA/FFA, particularly in the left hemisphere. Most importantly, immediate and delayed repetition of stimuli were also best captured by modulations of connections between EVC and OFA/FFA, but not self-connections of OFA/FFA, consistent with synchronization or predictive coding theories, though also possibly reflecting local mechanisms like synaptic depression. https://github.com/SMScottLee/Face_DCM_fMRI

URL:

Data available, click to request

Authors:

HUGHES, L.E., Adams, N.E., Lanskey, J., Naessens, M., ROUSE, M.E., Murley, A.G., Friston, K.J., ROWE, J.B.

Reference:

Year of publication:

2023

CBU number:

8912

Abstract:

We present a hierarchical empirical Bayesian framework for testing hypotheses about neurotransmitters’ concertation as empirical prior for synaptic physiology using ultra-high field magnetic resonance spectroscopy (7T-MRS) and magnetoencephalography data (MEG). A first level dynamic causal modelling of cortical microcircuits is used to infer the connectivity parameters of a generative model of individuals’ neurophysiological observations. At the second level, individuals’ 7T-MRS estimates of regional neurotransmitter concentration supply empirical priors on synaptic connectivity. We compare the group-wise evidence for alternative empirical priors, defined by monotonic functions of spectroscopic estimates, on subsets of synaptic connections. For efficiency and reproducibility, we used Bayesian model reduction (BMR), parametric empirical Bayes and variational Bayesian inversion. In particular, we used Bayesian model reduction to compare alternative model evidence of how spectroscopic neurotransmitter measures inform estimates of synaptic connectivity. This identifies the subset of synaptic connections that are influenced by individual differences in neurotransmitter levels, as measured by 7T-MRS. We demonstrate the method using resting-state MEG (i.e., task-free recording) and 7T-MRS data from healthy adults. Our results confirm the hypotheses that GABA concentration influences local recurrent inhibitory intrinsic connectivity in deep and superficial cortical layers, while glutamate influences the excitatory connections between superficial and deep layers and connections from superficial to inhibitory interneurons. Using within-subject split-sampling of the MEG dataset (i.e., validation by means of a held-out dataset), we show that model comparison for hypothesis testing can be highly reliable. The method is suitable for applications with magnetoencephalography or electroencephalography, and is well-suited to reveal the mechanisms of neurological and psychiatric disorders, including responses to psychopharmacological interventions. https://github.com/NIMG-22-2183/MRS-DCM

URL:

Data available, click to request

Authors:

Akkad, H., Hope, T.M.H., Howland, C., Ondobaka, S., Pappa, K., NARDO, D., DUNCAN, J., Leff, A.P., Crinion, J.

Reference:

Year of publication:

2023

CBU number:

8906

Abstract:

While language impairment is the defining symptom of aphasia, the co-occurrence of non-language cognitive deficits and their importance in predicting rehabilitation and recovery outcomes is well documented. Despite this, people with aphasia (PWA) are rarely tested on assessments of higher order cognitive functions, making it difficult for studies to associate these functions with a consistent lesion correlate. Contrary to classic models of speech and language, cumulative evidence shows that Broca’s area and surrounding regions in the left inferior frontal cortex (LIFC) are involved in, but not specific to, speech production – suggesting that these regions may be involved in higher-level cognitive functions that support language production. A better understanding of language processing in the context of other domain general cognitive functions is essential for improving aphasia treatments. This study aimed to explore the brain-behaviour relationships between tests of individual cognitive skill and language abilities in people with post-stroke aphasia, with a focus on language production deficits and their associated lesion correlates. We predicted our analysis would reveal a latent (non-language specific) cognitive component, that would be driven by damage to LIFC. We analysed the behavioural and neural correlates of an extensive battery of language and non-language cognitive tests in a sample of thirty-six adults with long-term speech production deficits from post-stroke aphasia. All participants were anomic, with relatively intact speech comprehension and no apraxia of speech. The behavioural variables were analysed using Principal Component Analysis and their neural correlates were estimated using Voxel-Based Correlational Morphology. A significant number of anomic adults showed impaired performance on tests of non-language specific cognitive function. The variance underlying behavioural performance was best captured by four orthogonal components, two higher-order cognitive components (executive functions and verbal working memory) and two linguistic processing components (phonology and semantics). Brain-behaviour relationships revealed separable neural correlates for each component in line with previous studies and an executive functions correlate in the left inferior frontal cortex (LIFC). Our findings suggest that in adults with chronic post-stroke language production deficits (anomia), higher-level cognitive functions explain more of the variance in language function than classical models of the condition imply. Additionally, lesions to the LIFC, including Broca’s area, were associated with executive (dys)function, independent of language abilities, suggesting that lesions to this area are associated with non-language specific higher-level cognitive functions that support speech production. These findings support contemporary models of speech production that place language processing within the context of domain-general perception, action and conceptual knowledge.

URL:

Data available, click to request