demo_trigger_Vol3ms.m

%% Demo for "Vol3ms" type scanner triggers
% Trigger type is found on the MRI sequence card
% special tab, "Trigger type" setting
%
% NB
% For "Vol3ms" triggers use KbTriggerWait()
% For "Slice3ms" triggers use Use KbWait() / KbPressWait() etc DO NOT use KbTriggerWait()
%     It misses every second trigger !!

%% Scan parameters
ndummies = 5;                                           % number of dummy volumes to wait for

%% PsychToolbox basic setup
PsychDefaultSetup(2);                                   % apply common Psychtoolbox parameters

%% Keyboard setup
KbName('UnifyKeyNames');
KbQueueRelease                                          % close keyboard queue
triggerKeys = KbName('5%');                             % Numeric keypad '5%' key for scanner triggers
ListenChar(0);                                          % disable character listening - to allow KbTriggerWait()

%% Wait for scanner
disp('Waiting for scanner...')
for n = 1:ndummies                                      % wait for dummy volumes
    t0 = KbTriggerWait(triggerKeys);                    % wait for a volume
    disp(['Vol ' num2str(n) ' @ time ' num2str(t0)])    % display timestamp & volume number
end

%% Present stimuli from here...

%% Tidy up & End
ListenChar(1)                                           % re-enable keyboard