Little is known about the neural mechanisms underlying top-down control of repetition priming. Here, we use functional brain imaging to investigate these mechanisms. Study and repetition tasks used a natural/man-made forced choice task. In the study phase subjects were required to respond to either pictures or words that were presented superimposed on each other. In the repetition phase only words were presented that were new, previously attended or ignored, or picture names that were derived from previously attended or ignored pictures. Relative to new words we found repetition priming for previously attended words. Previously ignored words showed a reduced priming effect, and there was no significant priming for pictures repeated as picture names. Brain imaging data showed that neural priming of words in the left prefrontal cortex (LIPFC) and left fusiform gyrus (LOTC) was affected by attention, semantic compatibility of superimposed stimuli during study and cross-modal priming. Neural priming reduced for words in the LIPFC and for words and pictures in the LOTC if stimuli were previously ignored. Previously ignored words that were semantically incompatible with a superimposed picture during study induce increased neural priming compared to semantically compatible ignored words (LIPFC) and decreased neural priming of previously attended pictures (LOTC). In summary, top-down control induces dissociable effects on neural priming by attention, cross-modal priming and semantic compatibility in a way that was not evident from behavioral results.
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http://dx.doi.org/10.1016/j.neuroimage.2006.11.013 | DOI Listing |
Mol Psychiatry
January 2025
Department of Psychiatry, University of Oxford, Oxford, UK.
Cognitive and neural mechanisms underlying bipolar disorder (BD) and its treatment are still poorly understood. Here we examined the role of adaptations in risk-taking using a reward-guided decision-making task. We recruited volunteers with high (n = 40) scores on the Mood Disorder Questionnaire, MDQ, suspected of high risk for bipolar disorder and those with low-risk scores (n = 37).
View Article and Find Full Text PDFJ Neurophysiol
January 2025
The Neuroimaging Research Group, Brain Sciences Center, Department of Veterans Affairs Health Care System, Minneapolis, MN, 55417, USA.
Performance of a task involves the engagement of various brain areas, as evidenced by the effects of lesions of particular brain areas and the results of functional neuroimaging and neurophysiological studies. Here we tested the hypothesis that overall task performance would depend on the level of ongoing, resting-state change in synaptic activity of participating areas, such that the degree of success of the outcome would be higher, the higher the resting-state activation. For that purpose, we used 248-sensor magnetoencephalography (MEG) in healthy people to obtain estimates of resting-state synaptic activity in various areas and then correlated those estimates to the average performance score in three visuospatial tasks assessed outside the MEG session using the Montreal Cognitive Assessment (MoCA), namely the Trails, Cube, and Clock Drawing (TCCD) tasks.
View Article and Find Full Text PDFBrain Res Bull
January 2025
Department of Traumatic Orthopedics, The Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, China. Electronic address:
Cerebrospinal fluid-contacting neurons (CSF-cNs) exhibit neural stem cell (NSC) properties both in vitro and in vivo, and they may play a critical role in recovery after spinal cord injury (SCI). GABA receptors (GABABRs) are expressed in Pkd2l1 CSF-cNs. However, their role in Pkd2l1 CSF-cNs still needs to be discovered.
View Article and Find Full Text PDFbioRxiv
January 2025
Department of Neuroscience, Brown University, Providence, RI, USA.
The process by which neocortical neurons and circuits amplify their response to an unexpected change in stimulus, often referred to as deviance detection (DD), has long been thought to be the product of specialized cell types and/or routing between mesoscopic brain areas. Here, we explore a different theory, whereby DD emerges from local network-level interactions within a neocortical column. We propose that deviance-driven neural dynamics can emerge through interactions between ensembles of neurons that have a fundamental inhibitory motif: competitive inhibition between reciprocally connected ensembles under modulation from feed-forward selective (dis)inhibition.
View Article and Find Full Text PDFKidney Res Clin Pract
January 2025
Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.
Background: Acute kidney injury (AKI) is a critical clinical condition that requires immediate intervention. We developed an artificial intelligence (AI) model called PRIME Solution to predict AKI and evaluated its ability to enhance clinicians' predictions.
Methods: The PRIME Solution was developed using convolutional neural networks with residual blocks on 183,221 inpatient admissions from a tertiary hospital (2013-2017) and externally validated with 4,501 admissions at another tertiary hospital (2020-2021).
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