Social and Behavioral Sciences Commons^™

Resting-State Network-Specific Breakdown Of Functional Connectivity During Ketamine Alteration Of Consciousness In Volunteers., Vincent Bonhomme, Audrey Vanhaudenhuyse, Athena Demertzi, Marie-Aurélie Bruno, Oceane Jaquet, Mohamed Ali Bahri, Alain Plenevaux, Melanie Boly, Pierre Boveroux, Andrea Soddu, Jean François Brichant, Pierre Maquet, Steven Laureys

Brain and Mind Institute Researchers' Publications

BACKGROUND: Consciousness-altering anesthetic agents disturb connectivity between brain regions composing the resting-state consciousness networks (RSNs). The default mode network (DMn), executive control network, salience network (SALn), auditory network, sensorimotor network (SMn), and visual network sustain mentation. Ketamine modifies consciousness differently from other agents, producing psychedelic dreaming and no apparent interaction with the environment. The authors used functional magnetic resonance imaging to explore ketamine-induced changes in RSNs connectivity.

METHODS: Fourteen healthy volunteers received stepwise intravenous infusions of ketamine up to loss of responsiveness. Because of agitation, data from six subjects were excluded from analysis. RSNs connectivity was compared between absence of …

Propofol-Induced Frontal Cortex Disconnection: A Study Of Resting-State Networks, Total Brain Connectivity, And Mean Bold Signal Oscillation Frequencies., Pieter Guldenmund, Ithabi S Gantner, Katherine Baquero, Tushar Das, Athena Demertzi, Pierre Boveroux, Vincent Bonhomme, Audrey Vanhaudenhuyse, Marie-Aurélie Bruno, Olivia Gosseries, Quentin Noirhomme, Muriëlle Kirsch, Mélanie Boly, Adrian M Owen, Steven Laureys, Francisco Gómez, Andrea Soddu

Brain and Mind Institute Researchers' Publications

Propofol is one of the most commonly used anesthetics in the world, but much remains unknown about the mechanisms by which it induces loss of consciousness. In this resting-state functional magnetic resonance imaging study, we examined qualitative and quantitative changes of resting-state networks (RSNs), total brain connectivity, and mean oscillation frequencies of the regional blood oxygenation level-dependent (BOLD) signal, associated with propofol-induced mild sedation and loss of responsiveness in healthy subjects. We found that detectability of RSNs diminished significantly with loss of responsiveness, and total brain connectivity decreased strongly in the frontal cortex, which was associated with increased mean oscillation …

Sensory Plasticity In Human Motor Learning., David J Ostry, Paul L Gribble

Brain and Mind Institute Researchers' Publications

There is accumulating evidence from behavioral, neurophysiological, and neuroimaging studies that the acquisition of motor skills involves both perceptual and motor learning. Perceptual learning alters movements, motor learning, and motor networks of the brain. Motor learning changes perceptual function and the sensory circuits of the brain. Here, we review studies of both human limb movement and speech that indicate that plasticity in sensory and motor systems is reciprocally linked. Taken together, this points to an approach to motor learning in which perceptual learning and sensory plasticity have a fundamental role.

A Selective Impairment Of Perception Of Sound Motion Direction In Peripheral Space: A Case Study., Lore Thaler, Joseph Paciocco, Mark Daley, Gabriella D Lesniak, David W Purcell, J Alexander Fraser, Gordon N Dutton, Stephanie Rossit, Melvyn A Goodale, Jody C Culham

Brain and Mind Institute Researchers' Publications

It is still an open question if the auditory system, similar to the visual system, processes auditory motion independently from other aspects of spatial hearing, such as static location. Here, we report psychophysical data from a patient (female, 42 and 44 years old at the time of two testing sessions), who suffered a bilateral occipital infarction over 12 years earlier, and who has extensive damage in the occipital lobe bilaterally, extending into inferior posterior temporal cortex bilaterally and into right parietal cortex. We measured the patient's spatial hearing ability to discriminate static location, detect motion and perceive motion direction in …

Correlation Between Resting State Fmri Total Neuronal Activity And Pet Metabolism In Healthy Controls And Patients With Disorders Of Consciousness., Andrea Soddu, Francisco Gómez, Lizette Heine, Carol Di Perri, Mohamed Ali Bahri, Henning U Voss, Marie-Aurélie Bruno, Audrey Vanhaudenhuyse, Christophe Phillips, Athena Demertzi, Camille Chatelle, Jessica Schrouff, Aurore Thibaut, Vanessa Charland-Verville, Quentin Noirhomme, Eric Salmon, Jean-Flory Luaba Tshibanda, Nicholas D Schiff, Steven Laureys

Brain and Mind Institute Researchers' Publications

INTRODUCTION: The mildly invasive 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) is a well-established imaging technique to measure 'resting state' cerebral metabolism. This technique made it possible to assess changes in metabolic activity in clinical applications, such as the study of severe brain injury and disorders of consciousness.

OBJECTIVE: We assessed the possibility of creating functional MRI activity maps, which could estimate the relative levels of activity in FDG-PET cerebral metabolic maps. If no metabolic absolute measures can be extracted, our approach may still be of clinical use in centers without access to FDG-PET. It also overcomes the problem of recognizing individual …