Publications by authors named "Vasilis M Karlaftis"

Experience and training are known to boost our skills and mold the brain's organization and function. Yet, structural plasticity and functional neurotransmission are typically studied at different scales (large-scale networks, local circuits), limiting our understanding of the adaptive interactions that support learning of complex cognitive skills in the adult brain. Here, we employ multimodal brain imaging to investigate the link between microstructural (myelination) and neurochemical (GABAergic) plasticity for decision-making.

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Learning and experience are known to improve our ability to make perceptual decisions. Yet, our understanding of the brain mechanisms that support improved perceptual decisions through training remains limited. Here, we test the neurochemical and functional interactions that support learning for perceptual decisions in the context of an orientation identification task.

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Background: The global COVID-19 pandemic has triggered a fundamental reexamination of how human psychological research can be conducted safely and robustly in a new era of digital working and physical distancing. Online web-based testing has risen to the forefront as a promising solution for the rapid mass collection of cognitive data without requiring human contact. However, a long-standing debate exists over the data quality and validity of web-based studies.

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The brain's capacity to adapt to sensory inputs is key for processing sensory information efficiently and interacting in new environments. Following repeated exposure to the same sensory input, brain activity in sensory areas is known to decrease as inputs become familiar, a process known as adaptation. Yet, the brain-wide mechanisms that mediate adaptive processing remain largely unknown.

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Adapting to the environment statistics by reducing brain responses to repetitive sensory information is key for efficient information processing. Yet, the fine-scale computations that support this adaptive processing in the human brain remain largely unknown. Here, we capitalise on the sub-millimetre resolution of ultra-high field imaging to examine functional magnetic resonance imaging signals across cortical depth and discern competing hypotheses about the brain mechanisms (feedforward vs.

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Article Synopsis
  • Successful human behavior relies on the brain's ability to understand and predict from complex information streams.
  • Individual differences in decision strategies when learning from these streams remain unclear, prompting investigation into how brain networks adapt based on these strategies.
  • The study reveals that different brain circuits are activated depending on whether individuals focus on exact sequence statistics or probable outcomes, suggesting that brain plasticity influences how people interpret changing environments.
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Article Synopsis
  • Research shows that learning enhances perceptual judgments by minimizing external noise and distractions in complex environments.
  • A study using ultra-high field magnetic resonance spectroscopy found that GABA (a neurotransmitter) levels in parietal and visual areas are linked to the brain's ability to suppress irrelevant information during training.
  • The results indicate that learning optimizes perceptual decisions through specific brain connectivity changes, highlighting the importance of both local and inter-cortical interactions in improving target detection and feature discrimination tasks.
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Extracting the statistics of event streams in natural environments is critical for interpreting current events and predicting future ones. The brain is known to rapidly find structure and meaning in unfamiliar streams of sensory experience, often by mere exposure to the environment (i.e.

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Making predictions about future events relies on interpreting streams of information that may initially appear incomprehensible. This skill relies on extracting regular patterns in space and time by mere exposure to the environment (i.e.

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