Hi Allen,
Dan Shima and I have been trying the GetCharWithTicks.dll you wrote
for Windows. If a character is available (i.e., CharAvail) before
the GetCharWithTicks line is reached, GetCharWithTicks returns the
most current tick value, not the tick value when the character was
pressed.
Here is a short program to demonstrate this. (And it also simulates
the basic routine for which we can not use KbCheck.) On our machine,
if a key is pressed during the WaitSecs(2) period, the reaction time
is always 2000 milliseconds insetad of something less.
clear all;
FlushEvents('keyDown');
fprintf('Press a key.\n');
starttick = GetRealTicks;
% Simulate 2 seconds of WAVRECORD command during which
% subject may or may not hit a key.
WaitSecs(2);
if (CharAvail)
disp('A key was pressed.');
[char, whentick] = GetCharWithTicks;
RT = whentick-starttick;
fprintf('Starttick is %0.0f.\n',starttick);
fprintf('Whentick is %0.0f.\n',whentick);
fprintf('Reaction Time is %0.0f milliseconds.\n',RT);
disp('Reaction Time seems to always be 2000 milliseconds.');
else
disp('No key was pressed during 2 seconds.');
end
Dan Shima and I have been trying the GetCharWithTicks.dll you wrote
for Windows. If a character is available (i.e., CharAvail) before
the GetCharWithTicks line is reached, GetCharWithTicks returns the
most current tick value, not the tick value when the character was
pressed.
Here is a short program to demonstrate this. (And it also simulates
the basic routine for which we can not use KbCheck.) On our machine,
if a key is pressed during the WaitSecs(2) period, the reaction time
is always 2000 milliseconds insetad of something less.
clear all;
FlushEvents('keyDown');
fprintf('Press a key.\n');
starttick = GetRealTicks;
% Simulate 2 seconds of WAVRECORD command during which
% subject may or may not hit a key.
WaitSecs(2);
if (CharAvail)
disp('A key was pressed.');
[char, whentick] = GetCharWithTicks;
RT = whentick-starttick;
fprintf('Starttick is %0.0f.\n',starttick);
fprintf('Whentick is %0.0f.\n',whentick);
fprintf('Reaction Time is %0.0f milliseconds.\n',RT);
disp('Reaction Time seems to always be 2000 milliseconds.');
else
disp('No key was pressed during 2 seconds.');
end