Visual Contrast Response Function Program
vb.net program: attachment:VisualResponseContrast
Participants view 10 levels of contrast in sine wave gratings presented as dynamic moving images surrounding a central fixation target spotting task (spot a target in a continuous stream of letters).
attachment:disc.PNG BR
Stimulus is displayed for 12 secs with a 6 sec blank screen rest period (target spotting task continues throughout rest and null trials)
Parameters
A block design is used to allow for maximal HRF values and return to baseline. Alternate runs of the constant stimulus and adaptive procedure.
4 epis (2 constant and 2 adaptive runs at 2.5 and 6.5 each) Measurements: 780BR TR 1 (64x64 matrix, 3x3x3.75mm voxels)BR 16 slices BR V1 ROI BR
Scanning Protocol: BR Gre_Field mappong sequence, EPIS (4 blocks, 12 minutes, 40 trials per block), standard CBU MPRAGE sequence