The Canadian Open Neuroscience Platform-An open science framework for the neuroscience community.

The Canadian Open Neuroscience Platform (CONP) takes a multifaceted approach to enabling open neuroscience, aiming to make research, data, and tools accessible to everyone, with the ultimate objective of accelerating discovery. Its core infrastructure is the CONP Portal, a repository with a decentralized design, where datasets and analysis tools across disparate platforms can be browsed, searched, accessed, and shared in accordance with FAIR principles. Another key piece of CONP infrastructure is NeuroLibre, a preprint server capable of creating and hosting executable and fully reproducible scientific publications that embed text, figures, and code. As part of its holistic approach, the CONP has also constructed frameworks and guidance for ethics and data governance, provided support and developed resources to help train the next generation of neuroscientists, and has fostered and grown an engaged community through outreach and communications. In this manuscript, we provide a high-level overview of this multipronged platform and its vision of lowering the barriers to the practice of open neuroscience and yielding the associated benefits for both individual researchers and the wider community.

Specialized neural dynamics for verbal and tonal memory: fMRI evidence in congenital amusia.

Behavioral and neuropsychological studies have suggested that tonal and verbal short-term memory are supported by specialized neural networks. To date however, neuroimaging investigations have failed to confirm this hypothesis. In this study, we investigated the hypothesis of distinct neural resources for tonal and verbal memory by comparing typical nonmusician listeners to individuals with congenital amusia, who exhibit pitch memory impairments with preserved verbal memory. During fMRI, amusics and matched controls performed delayed-match-to-sample tasks with tones and words and perceptual control tasks with the same stimuli. For tonal maintenance, amusics showed decreased activity in the right auditory cortex, inferior frontal gyrus (IFG) and dorso-lateral-prefrontal cortex (DLPFC). Moreover, they exhibited reduced right-lateralized functional connectivity between the auditory cortex and the IFG during tonal encoding and between the IFG and the DLPFC during tonal maintenance. In contrasts, amusics showed no difference compared with the controls for verbal memory, with activation in the left IFG and left fronto-temporal connectivity. Critically, we observed a group-by-material interaction in right fronto-temporal regions: while amusics recruited these regions less strongly for tonal memory than verbal memory, control participants showed the reversed pattern (tonal > verbal). By benefitting from the rare condition of amusia, our findings suggest specialized cortical systems for tonal and verbal short-term memory in the human brain.

Open Data governance at the Canadian Open Neuroscience Platform (CONP): From the Walled Garden to the Arboretum.

Scientific research communities pursue dual imperatives in implementing strategies to share their data. These communities attempt to maximize the accessibility of biomedical data for downstream research use, in furtherance of open science objectives. Simultaneously, such communities safeguard the interests of research participants through data stewardship measures and the integration of suitable risk disclosures to the informed consent process. The Canadian Open Neuroscience Platform (CONP) convened an Ethics and Governance Committee composed of experts in bioethics, neuroethics, and law to develop holistic policy tools, organizational approaches, and technological supports to align the open governance of data with ethical and legal norms. The CONP has adopted novel platform governance methods that favor full data openness, legitimated through the use of robust deidentification processes and informed consent practices. The experience of the CONP is articulated as a potential template for other open science efforts to further build upon. This experience highlights informed consent guidance, deidentification practices, ethicolegal metadata, platform-level norms, and commercialization and publication policies as the principal pillars of a practicable approach to the governance of open data. The governance approach adopted by the CONP stands as a viable model for the broader neuroscience and open science communities to adopt for sharing data in full open access.

The retention of simultaneous tones in auditory short-term memory: a magnetoencephalography study.

We used magnetoencephalography (MEG) to localize brain activity related to the retention of tones differing in pitch. Participants retained one or two simultaneously presented tones. After a two second interval a test tone was presented and the task was to determine if that tone was in memory. We focused on brain activity during the retention interval that increased as the number of sounds retained in auditory short-term memory (ASTM) increased. Source analyses revealed that the superior temporal gyrus in both hemispheres is involved in ASTM. In the right hemisphere, the inferior temporal gyrus, the inferior frontal gyrus, and parietal structures also play a role. Our method provides good spatial and temporal resolution for investigating neuronal correlates of ASTM and, as it is the first MEG study using a memory load manipulation without using sequences of tones, it allowed us to isolate brain regions that most likely reflect the simple retention of tones.

Sound processing hierarchy within human auditory cortex.

Both attention and masking sounds can alter auditory neural processes and affect auditory signal perception. In the present study, we investigated the complex effects of auditory-focused attention and the signal-to-noise ratio of sound stimuli on three different auditory evoked field components (auditory steady-state response, N1m, and sustained field) by means of magnetoencephalography. The results indicate that the auditory steady-state response originating in primary auditory cortex reflects the signal-to-noise ratio of physical sound inputs (bottom-up process) rather than the listener's attentional state (top-down process), whereas the sustained field, originating in nonprimary auditory cortex, reflects the attentional state rather than the signal-to-noise ratio. The N1m was substantially influenced by both bottom-up and top-down neural processes. The differential sensitivity of the components to bottom-up and top-down neural processes, contingent on their level in the processing pathway, suggests a stream from bottom-up driven sensory neural processing to top-down driven auditory perception within human auditory cortex.

Signal informativeness for sequence structure modulates human auditory cortical responses.

We observed how information about the structure of tone sequences modulates cortical responses in the context of a standard short-term memory (STM) task. Participants heard two sequences of one, three, or five tones (203 ms on, 203 ms off) interspersed by a silent interval (2 s) and decided whether the sequences were the same or different. In experiment 1, sequence length was randomized between trials. During the first sequence, the amplitude of the auditory P2 was larger for the second tone in trials with three tones, and for the second and fourth tone in trials with five tones. We hypothesize the increase in P2 reflected a dynamic disambiguation process because these tones were predictive of a sequence longer than one or three tones. This hypothesis was supported by the absence of P2 amplitude modulation during the second sequence (when sequence length was known). In experiment 2, we blocked trials by sequence length to ensure the effects were not caused by some process related to encoding in STM. There was no P2 amplitude modulation in either the first or second sequences. Thus, tones 2 and 4 had a larger amplitude only when they provided new information about the length of the current tone sequence. To some extent, the auditory N1 also showed those modulations. Independent Component Analysis of the ERPs provided evidence the modulations in P2 amplitude could originate in auditory cortex. These results suggest a rapid dynamic adaptation of auditory cortical responses based on the local informativeness of auditory signals.

A Simulation Toolkit for Testing the Sensitivity and Accuracy of Corticometry Pipelines.

In recent years, the replicability of neuroimaging findings has become an important concern to the research community. Neuroimaging pipelines consist of myriad numerical procedures, which can have a cumulative effect on the accuracy of findings. To address this problem, we propose a method for simulating artificial lesions in the brain in order to estimate the sensitivity and specificity of lesion detection, using different automated corticometry pipelines. We have applied this method to different versions of two widely used neuroimaging pipelines (CIVET and FreeSurfer), in terms of coefficients of variation; sensitivity and specificity of detecting lesions in 4 different regions of interest in the cortex, while introducing variations to the lesion size, the blurring kernel used prior to statistical analyses, and different thickness metrics (in CIVET). These variations are tested in a between-subject design (in two random groups, with and without lesions, using T1-weigted MRIs of 152 individuals from the International Consortium of Brain Mapping (ICBM) dataset) and in a within-subject pre-/post-lesion design [using 21 T1-Weighted MRIs of a single adult individual, scanned in the Infant Brain Imaging Study (IBIS)]. The simulation method is sensitive to partial volume effect and lesion size. Comparisons between pipelines illustrate the ability of this method to uncover differences in sensitivity and specificity of lesion detection. We propose that this method be adopted in the workflow of software development and release.

Neuroanatomical correlates of musicianship as revealed by cortical thickness and voxel-based morphometry.

We used a multimethod approach to investigate the neuroanatomical correlates of musicianship and absolute pitch (AP). Cortical thickness measures, interregional correlations applied to these thicknesses, and voxel-based morphometry (VBM) were applied to the same magnetic resonance imaging data set of 71 musicians (27 with AP) and 64 nonmusicians. Cortical thickness was greater in musicians with peaks in superior temporal and dorsolateral frontal regions. Correlations between 2 seed points, centered on peaks of thickness difference within the right frontal cortex, and all other points across the cortex showed greater specificity of significant correlations among musicians, with fewer and more discrete areas correlating with the frontal seeds, including the superior temporal cortex. VBM of gray matter (GM)-classified voxels yielded a strongly right-lateralized focus of greater GM concentration in musicians centered on the posterolateral aspect of Heschl's gyrus. Together, these results are consistent with functional evidence emphasizing the importance of a frontotemporal network of areas heavily relied upon in the performance of musical tasks. Among musicians, contrasts of AP possessors and nonpossessors showed significantly thinner cortex among possessors in a number of areas, including the posterior dorsal frontal cortices that have been previously implicated in the performance of AP tasks.

Mild traumatic brain injury: The effect of age at trauma onset on brain structure integrity.

Mounting evidence suggests that mild traumatic brain injuries (mTBI) have long-term effects that interact with the aging process to precipitate cognitive decline. This line of research predicts that early exposure to brain trauma is particularly detrimental to long-term brain integrity. However, a second line of research into the effects of age at trauma onset predict that older brains are more vulnerable to the effects of mTBI than younger brains. We sought to determine whether patients who sustain a mTBI earlier in life fare better than patients who sustain a mTBI at an older age. We conducted a multi-cohort, case-control study, with participants randomly sampled from a population of patients with a history of mTBI. We recruited two cohorts of aging participants (N = 74, mean [SD] = 61.16 [6.41]) matched in age and education levels that differed in only one respect: age at mTBI onset. One cohort sustained their concussion in their early twenties (24.60 [6.34] y/o), the other in their early sixties (61.05 [4.90] y/o). Each mTBI cohort had its own matched control group. Participants underwent high-resolution MRI at 3 Tesla for T1 and diffusion-weighted images (DWI) acquisition. Images were processed and analyzed using Deformation-Based Morphometry and DWI Tract-Based Spatial Statistics to identify group differences in a 2 × 2 ANOVA design. Results showed a significant interaction on DWI measures of white matter integrity indicating larger anomalies in participants who sustained a mTBI at a younger age (F1,70, P < .05, FDR corrected). These findings suggest that mTBI initiates a lifelong neurodegeneration process that outweighs the risks associated with sustaining a mTBI at an older age. Implications are important for young athletes' populations exposed to the risk of mTBI in the practice of their sports and for retired athletes aging with a history of concussions sustained at a younger age.

Functional changes in the cortical semantic network in amnestic mild cognitive impairment.

OBJECTIVE: Semantic memory impairment has been documented in individuals with amnestic Mild cognitive impairment (aMCI), who are at risk of developing Alzheimer's disease (AD), yet little is known about the neural basis of this breakdown. The aim of this study was to investigate the brain mechanisms associated with semantic performance in aMCI patients. METHOD: A group of aMCI patients and a group of healthy controls carried out a semantic categorization task while their brain activity was recorded using magnetoencephalography (MEG). During the task, participants were shown famous faces and had to determine whether each famous person matched a given occupation. The main hypotheses were that (a) semantic processing should be compromised for aMCI patients, and (b) these deficits should be associated with cortical dysfunctions within specific areas of the semantic network. RESULTS: Behavioral results showed that aMCI participants were significantly slower and less accurate than controls at the semantic task. Additionally, relative to controls, a significant pattern of hyperactivation was found in the aMCI group within specific regions of the extended semantic network, including the right anterior temporal lobe (ATL) and fusiform gyrus. CONCLUSIONS: Abnormal functional activation within key areas of the semantic network suggests that it is compromised early in the disease process. Moreover, this pattern of right ATL and fusiform gyrus hyperactivation was positively associated with gray matter integrity in specific areas, but was not associated with any pattern of atrophy, suggesting that this pattern of hyperactivation may precede structural alteration of the semantic network in aMCI. (PsycINFO Database Record

Conditional associative memory for musical stimuli in nonmusicians: implications for absolute pitch.

A previous positron emission tomography (PET) study of musicians with and without absolute pitch put forth the hypothesis that the posterior dorsolateral prefrontal cortex is involved in the conditional associative aspect of the identification of a pitch. In the work presented here, we tested this hypothesis by training eight nonmusicians to associate each of four different complex musical sounds (triad chords) with an arbitrary number in a task designed to have limited analogy to absolute-pitch identification. Each subject under-went a functional magnetic resonance imaging scanning procedure both before and after training. Active condition (identification of chords)-control condition (amplitude-matched noise bursts) comparisons for the pretraining scan showed no significant activation maxima. The same comparison for the posttraining scan revealed significant peaks of activation in posterior dorsolateral prefrontal, ventrolateral prefrontal, and parietal areas. A conjunction analysis was performed to show that the posterior dorsolateral prefrontal activity in this study is similar to that observed in the aforementioned PET study. We conclude that the posterior dorsolateral prefrontal cortex is selectively involved in the conditional association aspect of our task, as it is in the attribution of a verbal label to a note by absolute-pitch musicians.

Life-long music practice and executive control in older adults: An event-related potential study.

Recent research has indicated that music practice can influence cognitive processing across the lifespan. Although extensive musical experience may have a mitigating effect on cognitive decline in older adults, the nature of changes to brain functions underlying performance benefits remains underexplored. The present study was designed to investigate the underlying neural mechanisms that may support apparent beneficial effects of life-long musical practice on cognition. We recorded event-related potentials (ERPs) in older musicians (N=17; average age=69.2) and non-musicians (N=17; average age=69.9), matched for age and education, while they completed an executive control task (visual go/no-go). Whereas both groups showed similar response speed and accuracy on go trials, older musicians showed fewer no-go errors. ERP recordings revealed the typical N2/P3 complex, but the nature of these responses differed between groups in that (1) older musicians showed larger N2 and P3 effects ('no-go minus go' amplitude), with the N2 amplitude being correlated with behavioral accuracy for no-go trials and (2) the topography of the P3 response was more anterior in musicians. Moreover, P3 amplitude was correlated with measures of musical experience in musicians. In our discussion of these results, we propose that music practice may have conferred an executive control advantage for musicians in later life.

Differences in gray matter between musicians and nonmusicians.

Voxel-based morphometry is used to examine differences in cerebral morphology between musicians and nonmusicians. Principal results show differences in gray matter concentration in the right auditory cortex.

Saturation of auditory short-term memory causes a plateau in the sustained anterior negativity event-related potential.

The maintenance of information in auditory short-term memory (ASTM) is accompanied by a sustained anterior negativity (SAN) in the event-related potential measured during the retention interval of simple auditory memory tasks. Previous work on ASTM showed that the amplitude of the SAN increased in negativity as the number of maintained items increases. The aim of the current study was to measure the SAN and observe its behavior beyond the point of saturation of auditory short-term memory. We used atonal pure tones in sequences of 2, 4, 6, or 8t. Our results showed that the amplitude of SAN increased in negativity from 2 to 4 items and then levelled off from 4 to 8 items. Behavioral results suggested that the average span in the task was slightly below 3, which was consistent with the observed plateau in the electrophysiological results. Furthermore, the amplitude of the SAN predicted individual differences in auditory memory capacity. The results support the hypothesis that the SAN is an electrophysiological index of brain activity specifically related to the maintenance of auditory information in ASTM.

Electrophysiological correlates of the retention of tones differing in timbre in auditory short-term memory.

We examined the electrophysiological correlates of retention in auditory short-term memory (ASTM) for sequences of one, two, or three tones differing in timbre but having the same pitch. We focused on event-related potentials (ERPs) during the retention interval and revealed a sustained fronto-central ERP component (most likely a sustained anterior negativity; SAN) that became more negative as memory load increased. Our results are consistent with recent ERP studies on the retention of pitch and suggest that the SAN reflects brain activity mediating the low-level retention of basic acoustic features in ASTM. The present work shows that the retention of timbre shares common features with the retention of pitch, hence supporting the notion that the retention of basic sensory features is an active process that recruits modality-specific brain areas.

The absolute pitch mind continues to reveal itself.

Absolute pitch has proved useful as an alternative perspective from which to investigate various cognitive faculties. A new functional magnetic resonance imaging study published recently in BMC Neuroscience adds new data to the ongoing debate concerning the neural underpinnings of this unusual ability.