Sökning: "Stimulus extent"

Visar resultat 1 - 5 av 35 avhandlingar innehållade orden Stimulus extent.

  1. 1. Vision Beyond the Fovea: Evaluation and Stimuli Properties

    Författare :Abinaya Priya Venkataraman; Linda Lundström; Hema Radhakrishnan; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Peripheral vision; Visual optics; Optical correction; Orientation; Stimulus extent; Moving stimulus; Contrast sensitivity; Visual acuity; Central vision loss; Myopia; Biological Physics; Biologisk fysik;

    Sammanfattning : This research is about evaluating vision in the periphery. Peripheral vision is of fundamental importance in the performance of our everyday activities. The aim of this thesis is to develop methods suitable for the evaluation of peripheral vision and to assess how different visual functions vary across the visual field. LÄS MER

  3. 2. Chemical and stimulus-induced NMDA-dependent plasticity and the possible involved mechanisms

    Författare :Rui Li; Göteborgs universitet; []
    Nyckelord :synaptic plasticity; hippocampus; LTP; LTD; AMPA; NMDA; NR2A; NR2B;

    Sammanfattning : Long-term potentiation (LTP) and long-term depression (LTD) are considered as the most important forms of synaptic plasticity involved in learning and memory. The traditional way to induce LTP and LTD is by electric stimulation leading to activation of NMDA-R. LÄS MER

  4. 3. The direct current electroretinogram and the standing potential of the rabbit under different stimulus and adapting conditions

    Författare :Eva Gottvall; Linköpings universitet; []
    Nyckelord :MEDICINE; MEDICIN;

    Sammanfattning : The electroretinograrn (ERG) reflects the summation of electrical responses generated by neurons and non-neuronal cells in the retina and pigment epithelium in response to light. The major ERG components are the fast, negative a-wave, the fast, positive b-wave and the slow, positive c-wave. LÄS MER

  5. 4. Analysis and development of strategies for magnetic resonance functional neuroimaging

    Författare :Peter Fransson; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :neuroimaging; human brain; functional activation; magnetic resonance imaging; cerebral blood oxygenation;

    Sammanfattning : This thesis focuses on strategies for oxygenation-sensitive MRI that are designed to measure alterations in brain physiology induced by changes in neuronal activity. In a first study, it was shown that the temporal evolution of BOLD MRI signal changes in response to both brief and sustained visual activation are equally well visible in FLASH and EPI recordings. LÄS MER

  7. 5. Functional neuroimaging of dual task interference and divided attention

    Författare :Priyantha Herath; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :;

    Sammanfattning : It is known that human subjects cannot perform two reaction time (RT) tasks as efficiently as they would perform the constituent tasks individually. Increments of reaction times or error rates that occur when two RT tasks are performed nearly simultaneously is known as interference. LÄS MER