A5008713435- Functional Brain Connectivity Studies
- Neural dynamics and brain function
- Neural and Behavioral Psychology Studies
- EEG and Brain-Computer Interfaces
- Mental Health Research Topics
- Advanced Neuroimaging Techniques and Applications
- Face Recognition and Perception
- Advanced MRI Techniques and Applications
- Dementia and Cognitive Impairment Research
- Memory and Neural Mechanisms
- Visual perception and processing mechanisms
- Optical Imaging and Spectroscopy Techniques
- Neuroscience and Neuropharmacology Research
- stochastic dynamics and bifurcation
- Urban Transport and Accessibility
- Palliative Care and End-of-Life Issues
- Heart Rate Variability and Autonomic Control
- Older Adults Driving Studies
- Cognitive Abilities and Testing
- Neural Networks and Applications
- Evolutionary Psychology and Human Behavior
- Aging and Gerontology Research
- Spatial Neglect and Hemispheric Dysfunction
- Innovation Diffusion and Forecasting
- Communication in Education and Healthcare
Max Planck Institute for Human Development
2016-2025
University College London
2012-2025
Lifespan
2018-2024
Max Planck Institute for Biology of Ageing
2017-2024
Prostate Cancer Research
2017-2024
Max Planck Society
2013-2017
Wellcome Centre for Human Neuroimaging
2013
University of Toronto
2007-2012
Baycrest Hospital
2008-2012
University of Victoria
2003-2008
New work suggests that blood oxygen level-dependent (BOLD) signal variability can be a much more powerful index of human age than mean activation, and older brains are actually less variable younger brains. However, little is known how BOLD task performance may relate. In the current study, we examined in relation to age, reaction time speed consistency healthy (20–30 years) (56–85 adults on three cognitive tasks (perceptual matching, attentional cueing, delayed match-to-sample). Results...
Functional magnetic resonance imaging (fMRI) research often attributes blood oxygen level-dependent (BOLD) signal variance to measurement-related confounds. However, what is typically considered “noise” in data may be a vital feature of brain function. We examined fMRI variability during fixation baseline periods, and then compared SD- mean-based spatial patterns their relations with chronological age (20–85 years). found that not only was the SD-based pattern robust, it differed greatly,...
Increasing evidence suggests that brain variability plays a number of important functional roles for neural systems. However, the relationship between and changing cognitive demands remains understudied. In current study, we demonstrate experimental condition-based modulation in using magnetic resonance imaging. Within sample healthy younger older adults, found blood oxygen level–dependent signal was an effective discriminator fixation external demand. Across regions, increased broadly on...
A hallmark of electrophysiological brain activity is its 1/f-like spectrum – power decreases with increasing frequency. The steepness this ‘roll-off’ approximated by the spectral exponent, which in invasively recorded neural populations reflects balance excitatory to inhibitory (E:I balance). Here, we first establish that exponent non-invasive electroencephalography (EEG) recordings highly sensitive general (i.e., anaesthesia-driven) changes E:I balance. Building on EEG as a viable marker...
A well-known challenge for research in the cognitive neuropsychology of aging is to distinguish between deficits and changes associated with normal those indicative early impairment. In a series 2 studies, authors explored whether neurocognitive markers, speed (mean level) inconsistency (intraindividual variability), distinguished age groups (64-73 74-90+ years) status (nonimpaired, mildly impaired, moderately impaired). Study 1 (n = 416) showed that both level (not impaired) groups, modest...
Significance Cognitive functioning depends in part on dopamine neurotransmission the brain. Research implicates D1 receptor family cognitive functions linked to prefrontal cortex, such as working memory. The D2 has also been cognition, but it remains unclear which is specifically related. We examined relation of receptors episodic memory, and speed processing. caudate hippocampus were related memory modulated caudate–hippocampal functional connections. These findings link system...
Moment-to-moment brain signal variability is a ubiquitous neural characteristic, yet remains poorly understood. Evidence indicates that heightened can index and aid efficient function, but it not known whether responds to precise levels of environmental demand, or instead relatively static. Using multivariate modeling functional magnetic resonance imaging-based parametric face processing data, we show here within-person level incremental adjustments in task difficulty, manner entirely...
The average power of rhythmic neural responses as captured by MEG/EEG/LFP recordings is a prevalent index human brain function. Increasing evidence questions the utility trial-/group averaged estimates however, seemingly sustained activity patterns may be brought about time-varying transient signals in each single trial. Hence, it crucial to accurately describe duration and arrhythmic on trial-level. However, less clear how well this can achieved empirical recordings. Here, we extend an...
Significance Younger, better performing adults typically show greater brain signal variability than older, poorer performers, but the mechanisms underlying this observation remain elusive. We attempt to restore deficient functional-MRI–based blood oxygen level-dependent (BOLD) (SD BOLD ) levels in older by boosting dopamine via d -amphetamine (AMPH). Notably, met or exceeded young adult SD under AMPH. AMPH-driven changes also predicted reaction time speed and on a working memory task,...
Decision bias is traditionally conceptualized as an internal reference against which sensory evidence compared. Instead, we show that individuals implement decision by shifting the rate of accumulation toward a bound. Participants performed target detection task while recorded EEG. We experimentally manipulated participants' criterion for reporting targets using different stimulus-response reward contingencies, inducing either liberal or conservative bias. Drift diffusion modeling revealed...
Dopamine (DA) losses are associated with various aging-related cognitive deficits. Typically, higher moment-to-moment brain signal variability in large-scale patterns of voxels neocortical regions is linked to better performance and younger adult age, yet the physiological mechanisms regulating unknown. We explored relationship among DA availability, blood oxygen level-dependent (BOLD) variability, while older participants performed a spatial working memory (SWM) task. quantified striatal...
Abstract Knowledge about the relevance of environmental features can guide stimulus processing. However, it remains unclear how processing is adjusted when feature uncertain. We hypothesized that (a) heightened uncertainty would shift cortical networks from a rhythmic, selective processing-oriented state toward an asynchronous (“excited”) boosts sensitivity to all features, and (b) thalamus provides subcortical nexus for such uncertainty-related shifts. Here, we had young adults attend...
The human brain operates in large-scale functional networks. These networks are an expression of temporally correlated activity across regions, but how global network properties relate to the neural dynamics individual regions remains incompletely understood. Here, we show that brain's architecture is tightly linked critical episodes regularity, visible as spontaneous "complexity drops" magnetic resonance imaging signals. closely explain connectivity strength between subserve propagation...
Abstract During memory formation, the hippocampus is presumed to represent content of stimuli, but how it does so unknown. Using computational modelling and human single-neuron recordings, we show that more precisely hippocampal spiking variability tracks composite features each individual stimulus, better those stimuli are later remembered. We propose moment-to-moment may provide a new window into constructs memories from building blocks our sensory world.
A host of studies support that younger, better performing adults express greater moment-to-moment blood oxygen level-dependent (BOLD) signal variability (SDBOLD) in various cortical regions, supporting an emerging view the aging brain may undergo a generalized reduction dynamic range. However, exact physiological nature age differences SDBOLD remains understudied. In sample 29 younger and 45 older adults, we examined contribution vascular factors to group fixation-based using (1) dual-echo...
The comprehensive relations between healthy adult human brain white matter (WM) microstructure and gray (GM) function, their joint to cognitive performance, remain poorly understood. We investigated these associations in 27 younger 28 older adults by linking diffusion tensor imaging (DTI) with functional magnetic resonance (fMRI) data collected during an n-back working memory task. present a novel application of multivariate Partial Least Squares (PLS) analysis that permitted the...
Multiscale Entropy (MSE) is used to characterize the temporal irregularity of neural time series patterns. Due its’ presumed sensitivity non-linear signal characteristics, MSE typically considered a complementary measure brain dynamics variance and spectral power. However, divergence between these measures often unclear in application. Furthermore, it commonly assumed (yet sparingly verified) that entropy estimated at specific scales reflects those precise function. We argue such assumptions...
To determine the potential importance of several unexplored covariates everyday memory compensation, authors examined relations between responses on Memory Compensation Questionnaire (a self-report measure compensation) and cognitive reserve (education verbal IQ), subjective memory, life stress in 66 older adults (mean age = 70.55 years). Key results indicated that compensation occurred people (a) whose IQ level was greater than their education (representing "discordance") but not...