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// 1-back
var stimuli_1 = "C F B B Q S S C J D D B M Q Q C V V F J M M V Q Q C C D B B J S Q C C J J M F F",
// 2-back
stimuli_2 = "M F Q F J C J Q S Q S B D B M S M S D M D F B S V S V D Q B F D J D V S V B F M C",
// 3-back
stimuli_3 = "B S V C S D M B F M C F Q V S Q V D M F D V Q D C D J C J F V J S M B S D F S D B";
stimuli_1 = stimuli_1.split(' ');
stimuli_2 = stimuli_2.split(' ');
stimuli_3 = stimuli_3.split(' ');
function nback(stimuli,n)
{
main.setfontsize(60);
instruction('Watch the numbers on the screen. If the current number equals the one '
+ (n === 1 ? '<b>just seen before</b> ' : (n === 2 ? '<b>seen one before the last one</b>' : '<b>seen two before the last one</b>'))
+ ' tap or click the "Same" Button or press the space bar. Else, do nothing.<br /><br />'
+ ' When you click OK below, the experiment will start immediately.');
await(1000);
var i, e, current, last, hits = 0, same_ones = 0, false_alarms = 0,
wait_time = 2500, same = addblock(44,90,12,7).button("OK");
for (i = 0; i < stimuli.length; i++)
{
current = stimuli[i];
text(current,300);
waitfor {
await(500);
clear();
} and {
waitfor {
e = same.await('click',wait_time);
} or {
e = awaitkey(' ',wait_time);
}
clear();
}
if (i >= n && current === stimuli[i-n])
{
++same_ones;
}
if (i >= n && e.type !== 'timeout')
{
if (current === stimuli[i-n])
{
++hits;
}
else
{
++false_alarms;
}
}
await(1000);
}
text('You had ' + hits + ' out of ' + same_ones + ' similar ones correct '
+ 'and you responded ' + false_alarms + ' times when the digits were in fact different.');
same.button('Exit').await('click');
same.destroy();
}
function nback_example(n)
{
var stimulus_sets = [
['S','R','R','K','R','X','X'], // n = 1
['S','K'],
['V','X','X']
],
stimuli = stimulus_sets[n-1];
main.setfontsize(60);
instruction('First, we will do a brief example to get used to the task');
instruction('Watch the numbers on the screen. If the current number equals the one '
+ (n === 1 ? '<b>just seen before</b> ' : (n === 2 ? '<b>seen one before the last one</b>' : '<b>seen two before the last one</b>'))
+ ' tap or click the "Same" Button or press the space bar. Else, do nothing.<br /><br />'
+ ' When you click OK below, the experiment will start immediately.');
await(1000);
var i, e, current, last, hits = 0, same_ones = 0, false_alarms = 0,
wait_time = 2500, same = addblock(44,90,12,7).button("OK");
for (i = 0; i < stimuli.length; i++)
{
current = stimuli[i];
text(current,300);
waitfor {
await(500);
clear();
} and {
waitfor {
e = same.await('click',wait_time);
} or {
e = awaitkey(' ',wait_time);
}
clear();
}
if (i >= n && current === stimuli[i-n])
{
++same_ones;
if (e.type === 'timeout')
{
switch (n)
{
case 1:
alert("Here you should have responded because the current letter '"
+ current + "' equals the previous one");
break;
case 2:
alert("Here you should have responded because the current letter '"
+ current + "' equals the letter before the previous one");
break;
case 3:
alert("Here you should have responded because the current letter '"
+ current + "' equals the letter two before the previous one");
break;
}
}
}
if (i >= n && e.type !== 'timeout')
{
if (current === stimuli[i-n])
{
++hits;
}
else
{
++false_alarms;
switch (n)
{
case 1:
alert("Only respond if the current letter equals the previous one");
break;
case 2:
alert("Only respond if the current letter equals the one before the previous one");
break;
case 3:
alert("Only respond if the current letter equals the one two before the previous one");
break;
}
}
}
await(1000);
}
text('You had ' + hits + ' out of ' + same_ones + ' similar ones correct '
+ 'and you responded ' + false_alarms + ' times when the digits were in fact different.');
same.button('Exit').await('click');
same.destroy();
}
nback_example(2);
//nback(stimuli_1,1);
//nback(stimuli_2,2);
//nback(stimuli_3,3);
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