Physiological Methods Flashcards
why do we not always add physiological measures
- often takes a lot more time
* techniques themselves are quite complicated in terms of machinery
why do we use physiological methods
- depends on the research question
* can be more sensitive than behavioural data
what does galvanic skip response measure
increases in conductance between two electrodes
- a v low electronic voltage is applied
- often measured in palms and/or fingers
why are we interested in galvanic skin response
- autonomic nervous system
- stress,arousal,emotion,increase activity of sweat glands
heart rate
- increased heart rate is linked to increase in stress arousal emotion ect
- many different ways to measure heart rate
measuring eye movement -autonomic nervous system
pupil constriction/dilation
eye tracking
*using camera and specific software - exact location of a gaze can be determined
what can we use eye tracking for
to study visual information processing and attentional processes
how are eye movements measured
p’s are shown images while their eye movement is recorded
what are the measurements of eye movements
fixation
saccades
what are saccades
rapid eye movement between fixations
what does MRI stand for
Magnetic Resonance Imaging
how does an MRI work
measures the change in magnetic field within a voxel
whats a voxel
a cube which is the smallest measurement point
what are MRI pictures
slices of the brain usually in one of three directions
-3D modelling allows for easy navigation
what does DTI stand for
diffusion tensor imaging
what is DTI
an MRI technique
how does DTI work
if unobstructed water molecules diffuse randomly in any direction
- BUT the axons are bubbled together and have myelin sheilds
what do myelin sheilds do
block the molecules, forcing pattern
what can voxels be checked for
- rate of diffusion
- preferred direction of diffusion
what do elongated ellipsoids indicate
the presence and direction of homogeneous fibre tracts within a voxel
what are DTI’s especially useful for
identifying network connections (or white matter connectivity)
how can DTI’s be used in a clinical setting
to detect tumors in relation to the white matter tracts
problems with DTI
technique is not perfect and has difficulties with ‘crossing fibers’
