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Articles 31 - 48 of 48
Full-Text Articles in Medicine and Health Sciences
The Material-Weight Illusion Disappears Or Inverts In Objects Made Of Two Materials, Vivian C. Paulun, Gavin Buckingham, Melvyn A. Goodale, Roland W. Fleming
The Material-Weight Illusion Disappears Or Inverts In Objects Made Of Two Materials, Vivian C. Paulun, Gavin Buckingham, Melvyn A. Goodale, Roland W. Fleming
Brain and Mind Institute Researchers' Publications
© the American Physiological Society. The material-weight illusion disappears or inverts in objects made of two materials. J Neurophysiol 121: 996 –1010, 2019. First published January 23, 2019; doi:10.1152/jn.00199.2018.—The material-weight illusion (MWI) occurs when an object that looks heavy (e.g., stone) and one that looks light (e.g., Styrofoam) have the same mass. When such stimuli are lifted, the heavier-looking object feels lighter than the lighter-looking object, presumably because well-learned priors about the density of different materials are violated. We examined whether a similar illusion occurs when a certain weight distribution is expected (such as the metal end of a hammer …
The Gradient Of The Reinforcement Landscape Influences Sensorimotor Learning, Joshua G.A. Cashaback, Christopher K. Lao, Dimitrios J. Palidis, Susan K. Coltman, Heather R. Mcgregor, Paul L. Gribble
The Gradient Of The Reinforcement Landscape Influences Sensorimotor Learning, Joshua G.A. Cashaback, Christopher K. Lao, Dimitrios J. Palidis, Susan K. Coltman, Heather R. Mcgregor, Paul L. Gribble
Brain and Mind Institute Researchers' Publications
© 2019 Cashaback et al. Consideration of previous successes and failures is essential to mastering a motor skill. Much of what we know about how humans and animals learn from such reinforcement feedback comes from experiments that involve sampling from a small number of discrete actions. Yet, it is less understood how we learn through reinforcement feedback when sampling from a continuous set of possible actions. Navigating a continuous set of possible actions likely requires using gradient information to maximize success. Here we addressed how humans adapt the aim of their hand when experiencing reinforcement feedback that was associated with …
Understanding Perirhinal Contributions To Perception And Memory: Evidence Through The Lens Of Selective Perirhinal Damage, Marika C. Inhoff, Andrew C. Heusser, Arielle Tambini, Chris B. Martin, Edward B. O'Neil, Stefan Köhler, Michael R. Meager, Karen Blackmon, Blanca Vazquez, Orrin Devinsky, Lila Davachi
Understanding Perirhinal Contributions To Perception And Memory: Evidence Through The Lens Of Selective Perirhinal Damage, Marika C. Inhoff, Andrew C. Heusser, Arielle Tambini, Chris B. Martin, Edward B. O'Neil, Stefan Köhler, Michael R. Meager, Karen Blackmon, Blanca Vazquez, Orrin Devinsky, Lila Davachi
Brain and Mind Institute Researchers' Publications
© 2019 Elsevier Ltd Although a memory systems view of the medial temporal lobe (MTL) has been widely influential in understanding how memory processes are implemented, a large body of work across humans and animals has converged on the idea that the MTL can support various other decisions, beyond those involving memory. Specifically, recent work suggests that perception of and memory for visual representations may interact in order to support ongoing cognition. However, given considerations involving lesion profiles in neuropsychological investigations and the correlational nature of fMRI, the precise nature of representations supported by the MTL are not well understood …
Intrinsic Functional Boundaries Of Lateral Frontal Cortex In The Common Marmoset Monkey, David J. Schaeffer, Kyle M. Gilbert, Joseph S. Gati, Ravi S. Menon, Stefan Everling
Intrinsic Functional Boundaries Of Lateral Frontal Cortex In The Common Marmoset Monkey, David J. Schaeffer, Kyle M. Gilbert, Joseph S. Gati, Ravi S. Menon, Stefan Everling
Brain and Mind Institute Researchers' Publications
© 2019 the authors. The common marmoset (Callithrix jacchus) is a small New World primate species that has been recently targeted as a potentially powerful preclinical model of human prefrontal cortex dysfunction. Although the structural boundaries of frontal cortex were described in marmosets at the start of the 20th century (Brodmann, 1909) and refined more recently (Paxinos et al., 2012), the broad functional boundaries of marmoset frontal cortex have yet to be established. In this study, we sought to functionally derive boundaries of the marmoset lateral frontal cortex (LFC) using ultra-high field (9.4 T) resting-state functional magnetic resonance imaging (RS-fMRI). …
Human Consciousness Is Supported By Dynamic Complex Patterns Of Brain Signal Coordination, A. Demertzi, E. Tagliazucchi, S. Dehaene, G. Deco, P. Barttfeld, F. Raimondo, C. Martial, D. Fernández-Espejo, B. Rohaut, H. U. Voss, N. D. Schiff, A. M. Owen, S. Laureys, L. Naccache, J. D. Sitt
Human Consciousness Is Supported By Dynamic Complex Patterns Of Brain Signal Coordination, A. Demertzi, E. Tagliazucchi, S. Dehaene, G. Deco, P. Barttfeld, F. Raimondo, C. Martial, D. Fernández-Espejo, B. Rohaut, H. U. Voss, N. D. Schiff, A. M. Owen, S. Laureys, L. Naccache, J. D. Sitt
Brain and Mind Institute Researchers' Publications
Adopting the framework of brain dynamics as a cornerstone of human consciousness, we determined whether dynamic signal coordination provides specific and generalizable patterns pertaining to conscious and unconscious states after brain damage. A dynamic pattern of coordinated and anticoordinated functional magnetic resonance imaging signals characterized healthy individuals and minimally conscious patients. The brains of unresponsive patients showed primarily a pattern of low interareal phase coherence mainly mediated by structural connectivity, and had smaller chances to transition between patterns. The complex pattern was further corroborated in patients with covert cognition, who could perform neuroimaging mental imagery tasks, validating this pattern’s implication …
Unmet Need For Mental Health Services Among People Screened But Not Admitted To An Early Psychosis Intervention Program, Jordan Edwards, Ross Norman, Paul Kurdyak, Arlene G. Macdougall, Lena Palaniyappan, Cindy Lau, Kelly K. Anderson
Unmet Need For Mental Health Services Among People Screened But Not Admitted To An Early Psychosis Intervention Program, Jordan Edwards, Ross Norman, Paul Kurdyak, Arlene G. Macdougall, Lena Palaniyappan, Cindy Lau, Kelly K. Anderson
Brain and Mind Institute Researchers' Publications
Information is lacking on people screened for early psychosis intervention (EPI) but not admitted to the program. Using health administrative data, we constructed a retrospective cohort of incident cases of psychosis in the catchment of an EPI program. Use of mental health services was compared between people screened and not admitted with an EPI-admitted group. The non-admitted group had higher rates of subsequent emergency department visits, psychiatric hospitalizations, and involuntary admissions. These patterns are indicative of unmet need, and people screened but not admitted to EPI may benefit from protocols to improve transitions of care with other service providers.
Obtaining And Maintaining Cortical Hand Representation As Evidenced From Acquired And Congenital Handlessness, Daan B. Wesselink, Fiona Mz Van Den Heiligenberg, Naveed Ejaz, Harriet Dempsey-Jones, Lucilla Cardinali, Aurelie Tarall-Jozwiak, Jörn Diedrichsen, Tamar R. Makin
Obtaining And Maintaining Cortical Hand Representation As Evidenced From Acquired And Congenital Handlessness, Daan B. Wesselink, Fiona Mz Van Den Heiligenberg, Naveed Ejaz, Harriet Dempsey-Jones, Lucilla Cardinali, Aurelie Tarall-Jozwiak, Jörn Diedrichsen, Tamar R. Makin
Brain and Mind Institute Researchers' Publications
© Lukinova et al. A key question in neuroscience is how cortical organisation relates to experience. Previously we showed that amputees experiencing highly vivid phantom sensations maintain cortical representation of their missing hand (Kikkert et al., 2016). Here, we examined the role of sensory hand experience on persistent hand representation by studying individuals with acquired and congenital hand loss. We used representational similarity analysis in primary somatosensory and motor cortex during missing and intact hand movements. We found that key aspects of acquired amputees’ missing hand representation persisted, despite varying vividness of phantom sensations. In contrast, missing hand representation of …
Dorsal Striatum Does Not Mediate Feedback-Based, Stimulus-Response Learning: An Event-Related Fmri Study In Patients With Parkinson's Disease Tested On And Off Dopaminergic Therapy, Nole M. Hiebert, Adrian M. Owen, Hooman Ganjavi, Daniel Mendonça, Mary E. Jenkins, Ken N. Seergobin, Penny A. Macdonald
Dorsal Striatum Does Not Mediate Feedback-Based, Stimulus-Response Learning: An Event-Related Fmri Study In Patients With Parkinson's Disease Tested On And Off Dopaminergic Therapy, Nole M. Hiebert, Adrian M. Owen, Hooman Ganjavi, Daniel Mendonça, Mary E. Jenkins, Ken N. Seergobin, Penny A. Macdonald
Brain and Mind Institute Researchers' Publications
© 2018 Learning associations between stimuli and responses is essential to everyday life. Dorsal striatum (DS) has long been implicated in stimulus-response learning, though recent results challenge this contention. We have proposed that discrepant findings arise because stimulus-response learning methodology generally confounds learning and response selection processes. In 19 patients with Parkinson's disease (PD) and 18 age-matched controls, we found that dopaminergic therapy decreased the efficiency of stimulus-response learning, with corresponding attenuation of ventral striatum (VS) activation. In contrast, exogenous dopamine improved response selection accuracy related to enhanced DS BOLD signal. Contrasts between PD patients and controls fully support these …
Investigating The Visual Number Form Area: A Replication Study, Rebecca Merkley, Benjamin Conrad, Gavin Price, Daniel Ansari
Investigating The Visual Number Form Area: A Replication Study, Rebecca Merkley, Benjamin Conrad, Gavin Price, Daniel Ansari
Brain and Mind Institute Researchers' Publications
© 2019 The Authors. Published by the Royal Society The influential triple-code model of number representation proposed that there are three distinct brain regions for three different numerical representations: verbal words, visual digits and abstract magnitudes. It was hypothesized that the region for visual digits, known as the number form area, would be in ventral occipitotemporal cortex (vOTC), near other visual category-specific regions, such as the visual word form area. However, neuroimaging investigations searching for a region that responds in a category-specific manner to the visual presentation of number symbols have yielded inconsistent results. Price & Ansari (Price, Ansari 2011 …
A Touchscreen Motivation Assessment Evaluated In Huntington's Disease Patients And R6/1 Model Mice, Christopher J. Heath, Claire O'Callaghan, Sarah L. Mason, Benjamin U. Phillips, Lisa M. Saksida, Trevor W. Robbins, Roger A. Barker, Timothy J. Bussey, Barbara J. Sahakian
A Touchscreen Motivation Assessment Evaluated In Huntington's Disease Patients And R6/1 Model Mice, Christopher J. Heath, Claire O'Callaghan, Sarah L. Mason, Benjamin U. Phillips, Lisa M. Saksida, Trevor W. Robbins, Roger A. Barker, Timothy J. Bussey, Barbara J. Sahakian
Brain and Mind Institute Researchers' Publications
Copyright © 2019 Heath, O'Callaghan, Mason, Phillips, Saksida, Robbins, Barker, Bussey and Sahakian. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. Apathy is pervasive across many neuropsychiatric disorders but is poorly characterized mechanistically, so targeted therapeutic interventions remain elusive. A key …
White Matter Injury Predicts Disrupted Functional Connectivity And Microstructure In Very Preterm Born Neonates, Emma G. Duerden, Sheliza Halani, Karin Ng, Ting Guo, Justin Foong, Torin J.A. Glass, Vann Chau, Helen M. Branson, John G. Sled, Hilary E. Whyte, Edmond N. Kelly, Steven P. Miller
White Matter Injury Predicts Disrupted Functional Connectivity And Microstructure In Very Preterm Born Neonates, Emma G. Duerden, Sheliza Halani, Karin Ng, Ting Guo, Justin Foong, Torin J.A. Glass, Vann Chau, Helen M. Branson, John G. Sled, Hilary E. Whyte, Edmond N. Kelly, Steven P. Miller
Brain and Mind Institute Researchers' Publications
© 2018 The Authors Objective: To determine whether the spatial extent and location of early-identified punctate white matter injury (WMI) is associated with regionally-specific disruptions in thalamocortical-connectivity in very-preterm born neonates. Methods: 37 very-preterm born neonates (median gestational age: 28.1 weeks; interquartile range [IQR]: 27–30) underwent early MRI (median age 32.9 weeks; IQR: 32–35), and WMI was identified in 13 (35%) neonates. Structural T1-weighted, resting-state functional Magnetic Resonance Imaging (rs-fMRI, n = 34) and Diffusion Tensor Imaging (DTI, n = 31) sequences were acquired using 3 T-MRI. A probabilistic map of WMI was developed for the 13 neonates demonstrating brain …
Brain Activation Time-Locked To Sleep Spindles Associated With Human Cognitive Abilities, Zhuo Fang, Laura B. Ray, Adrian M. Owen, Stuart M. Fogel
Brain Activation Time-Locked To Sleep Spindles Associated With Human Cognitive Abilities, Zhuo Fang, Laura B. Ray, Adrian M. Owen, Stuart M. Fogel
Brain and Mind Institute Researchers' Publications
Simultaneous electroencephalography and functional magnetic resonance imaging (EEG-fMRI) studies have revealed brain activations time-locked to spindles. Yet, the functional significance of these spindle-related brain activations is not understood. EEG studies have shown that inter-individual differences in the electrophysiological characteristics of spindles (e.g., density, amplitude, duration) are highly correlated with "Reasoning" abilities (i.e., "fluid intelligence"; problem solving skills, the ability to employ logic, identify complex patterns), but not short-term memory (STM) or verbal abilities. Spindle-dependent reactivation of brain areas recruited during new learning suggests night-to-night variations reflect offline memory processing. However, the functional significance of stable, trait-like inter-individual differences in brain …
The Neural Basis Of External Responsiveness In Prolonged Disorders Of Consciousness, Clara A. Stafford, Adrian M. Owen, Davinia Fernández-Espejo
The Neural Basis Of External Responsiveness In Prolonged Disorders Of Consciousness, Clara A. Stafford, Adrian M. Owen, Davinia Fernández-Espejo
Brain and Mind Institute Researchers' Publications
Objective: To investigate the structural integrity of fibre tracts underlying overt motor behaviour in PDOC. Methods: This cross-sectional study examined 15 PDOC patients and 22 healthy participants. Eight PDOC patients met the criteria for the vegetative state, 5 met the criteria for the minimally conscious state and 2 met the criteria for emerging from the minimally conscious state. We used fibre tractography to reconstruct the white matter fibres known to be involved in voluntary motor execution (i.e., those connecting thalamus with M1, M1 with cerebellum, and cerebellum with thalamus) and used fractional anisotropy (FA) as a measure of their integrity. …
Translational Tests Involving Non-Reward: Methodological Considerations, Benjamin U. Phillips, Laura Lopez-Cruz, Lisa M. Saksida, Timothy J. Bussey
Translational Tests Involving Non-Reward: Methodological Considerations, Benjamin U. Phillips, Laura Lopez-Cruz, Lisa M. Saksida, Timothy J. Bussey
Brain and Mind Institute Researchers' Publications
© 2018, The Author(s). This review is concerned with methods for assessing the processing of unrewarded responses in experimental animals and the mechanisms underlying performance of these tasks. A number of clinical populations, including Parkinson’s disease, depression, compulsive disorders, and schizophrenia demonstrate either abnormal processing or learning from non-rewarded responses in laboratory-based reinforcement learning tasks. These effects are hypothesized to result from disturbances in modulatory neurotransmitter systems, including dopamine and serotonin. Parallel work in experimental animals has revealed consistent behavioral patterns associated with non-reward and, consistent with the human literature, modulatory roles for specific neurotransmitters. Classical tests involving an important …
Girls' Internalizing Symptoms And White Matter Tracts In Cortico-Limbic Circuitry, Ola Mohamed Ali, Matthew R.J. Vandermeer, Haroon I. Sheikh, Marc F. Joanisse, Elizabeth P. Hayden
Girls' Internalizing Symptoms And White Matter Tracts In Cortico-Limbic Circuitry, Ola Mohamed Ali, Matthew R.J. Vandermeer, Haroon I. Sheikh, Marc F. Joanisse, Elizabeth P. Hayden
Brain and Mind Institute Researchers' Publications
© 2019 The Authors Dysfunction in cortico-limbic circuitry is implicated in internalizing disorders (i.e., depressive and anxious disorders), but less is known about whether structural variations precede frank disorder and thus potentially mark risk. We therefore examined associations between white matter (WM) tract microstructure in cortico-limbic circuitry at age 7 and concurrent and longitudinal patterns of internalizing symptoms in 42 typically developing girls using Diffusion Tensor Imaging (DTI). Girls' internalizing symptoms were concurrently associated with reduced fractional anisotropy (FA) in segments of the cingulum bundle (CB) and the uncinate fasciculus (UF), bilaterally. Moreover, latent profile analysis showed that girls with …
Alive Inside, Andrew Peterson, Adrian M. Owen, Jason Karlawish
Alive Inside, Andrew Peterson, Adrian M. Owen, Jason Karlawish
Brain and Mind Institute Researchers' Publications
This article provides an ethical analysis of the U.S. practice guideline update on disorders of consciousness. Our analysis focuses on the guideline’s recommendations regarding the use of investigational neuroimaging methods to assess brain-injured patients. Complex and multifaceted ethical issues have emerged because these methods alter the clinical understanding of consciousness. We address issues of false hope, patient suffering, and cost. We argue that, in spite of these concerns, there is significant benefit to using neuroimaging to assess brain-injured patients in most cases.
Biomarkers Of Parkinson's Disease: Striatal Sub-Regional Structural Morphometry And Diffusion Mri, Ali R. Khan, Nole M. Hiebert, Andrew Vo, Brian T. Wang, Adrian M. Owen, Ken N. Seergobin, Penny A. Macdonald
Biomarkers Of Parkinson's Disease: Striatal Sub-Regional Structural Morphometry And Diffusion Mri, Ali R. Khan, Nole M. Hiebert, Andrew Vo, Brian T. Wang, Adrian M. Owen, Ken N. Seergobin, Penny A. Macdonald
Brain and Mind Institute Researchers' Publications
© 2018 The Authors Parkinson's disease (PD) is a progressive neurological disorder that has no reliable biomarkers. The aim of this study was to explore the potential of semi-automated sub-regional analysis of the striatum with magnetic resonance imaging (MRI) to distinguish PD patients from controls (i.e., as a diagnostic biomarker) and to compare PD patients at different stages of disease. With 3 Tesla MRI, diffusion- and T1-weighted scans were obtained on two occasions in 24 PD patients and 18 age-matched, healthy controls. PD patients completed one session on and the other session off dopaminergic medication. The striatum was parcellated into …
Linked Mri Signatures Of The Brain's Acute And Persistent Response To Concussion In Female Varsity Rugby Players, Kathryn Y. Manning, Alberto Llera, Gregory A. Dekaban, Robert Bartha, Christy Barreira, Arthur Brown, Lisa Fischer, Tatiana Jevremovic, Kevin Blackney, Timothy J. Doherty, Douglas D. Fraser, Jeff Holmes, Christian F. Beckmann, Ravi S. Menon
Linked Mri Signatures Of The Brain's Acute And Persistent Response To Concussion In Female Varsity Rugby Players, Kathryn Y. Manning, Alberto Llera, Gregory A. Dekaban, Robert Bartha, Christy Barreira, Arthur Brown, Lisa Fischer, Tatiana Jevremovic, Kevin Blackney, Timothy J. Doherty, Douglas D. Fraser, Jeff Holmes, Christian F. Beckmann, Ravi S. Menon
Brain and Mind Institute Researchers' Publications
Acute brain changes are expected after concussion, yet there is growing evidence of persistent abnormalities well beyond clinical recovery and clearance to return to play. Multiparametric MRI is a powerful approach to non-invasively study structure-function relationships in the brain, however it remains challenging to interpret the complex and heterogeneous cascade of brain changes that manifest after concussion. Emerging conjunctive, data-driven analysis approaches like linked independent component analysis can integrate structural and functional imaging data to produce linked components that describe the shared inter-subject variance across images. These linked components not only offer the potential of a more comprehensive understanding of …