Sökning: "brain activity"

Visar resultat 11 - 15 av 818 avhandlingar innehållade orden brain activity.

  1. 11. Segmentation and Visualisation of Human Brain Structures

    Författare :Roger Hult; Ewert Bengtsson; Lennart Thurfjell; Håkan Hall; Ingrid Agartz; Arvid Lundervold; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Bildanalys; segmentation; visualisation; brain; cortex; hippocampus; autoradiography; MRI; PET; ROI; Bildanalys; Image analysis; Bildanalys; Computerized Image Analysis; datoriserad bildanalys;

    Sammanfattning : In this thesis the focus is mainly on the development of segmentation techniques for human brain structures and of the visualisation of such structures. The images of the brain are both anatomical images (magnet resonance imaging (MRI) and autoradigraphy) and functional images that show blood flow (functional magnetic imaging (fMRI), positron emission tomography (PET), and single photon emission tomograpy (SPECT)). LÄS MER

  3. 12. The conscious brain : Empirical investigations of the neural correlates of perceptual awareness

    Författare :Johan Eriksson; Lars Nyberg; Geraint Rees; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; consciousness; visual perception; object identification; functional neuroimaging; top-down processing; prefrontal cortex; auditory perception; Neuroscience; Neurovetenskap;

    Sammanfattning : Although consciousness has been studied since ancient time, how the brain implements consciousness is still considered a great mystery by most. This thesis investigates the neural correlates of consciousness by measuring brain activity with functional magnetic resonance imaging (fMRI) while specific contents of consciousness are defined and maintained in various experimental settings. LÄS MER

  4. 13. Brain activity associated with episodic memory : similarities and differences between encoding and retrieval

    Författare :Jonas Persson; Umeå universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Episodic memory; encoding; retrieval; positron emission tomography PET ; enactment; overlap; retrieval mode; retrieval success; novelty;

    Sammanfattning : Understanding the mnemonic functions of the brain has been extensively facilitated by the development of functional neuroimaging techniques such as positron emission tomography (PET) and functional magnetic resonance imaging (fMRI). The present thesis aims at investigating the neural mechanisms underlying memory for personally experienced events (episodic memory), using PET. LÄS MER

  5. 14. Effect of timing training in golf and soccer players : skill, movement organization, and brain activity

    Författare :Marius Sommer; Louise Rönnqvist; Charlotte Häger; Nicola Hodges; Umeå universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Motor timing; rhythmicity; timing training; golf shot; golf swing; kinematics; precision; variability; coordination; movement dynamics; soccer; fMRI; mirror neurons; action observation; cerebellum; perception - action.; Psychology; psykologi;

    Sammanfattning : Background Although trainers and athletes consider ‘good timing skills’ to be critical for optimal sport performance, little is known in regard to how sport-specific skills may benefit from timing training. Thus, assuming that all motor performances are mediated by an internal timing mechanism, enhanced motor timing is expected to have positive effects on both planning and execution of movement performance, and consequently on complex sports actions as golf or soccer. LÄS MER

  7. 15. Mammalian brain acetylcholinesterase : a study of its solubilization, purification, molecular state and interactions with cholinergic ligands including an endogenous modulator

    Författare :Bertil Niklasson; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Affinity chromatography; caudate nucleus; acetylcholinesterase; tetracaine; décaméthonium; d-tubocurarine; edrophonium; fluoride ion; hysteric properties; endogenous ligands to AChE;

    Sammanfattning : Membrane bound AChE from calf brain caudate nucleus was solubilized by use of ion-free media in presence of 10~ M EDTA and 10“5M tetracaine. The irreversible release of AChE was more effectively inhibited by divalent ions compared to monovalent ions added to the medium. LÄS MER