Deal Inquisiters,
I am trying to build an experiment in which participants are presented with circles of different colors, displayed behind a checkerboard.
Whenever the darker circle is presented on the screen (in the code red_circle), they have to press the spacebar by synchronizing the more they can their response with the appearance of the figure on the screen.
The problem is that I want to calculate their accuracy in giving this response for each trial. The accuracy is calculated according to the distance between each spacebar press and each circle appearance. Specifically, the response is considered accurate whenever they managed to press the spacebar in a time window comprised between 125 ms after & -750 ms before the real appearance of the red circle. The problem is that we have many circles displayed within a single trial == many responses given and many latencies. For each of these latencies, we need to repeat this procedure, that is : calculate if every single response can be considered accurate vs. inaccurate (calculated according to the explained criteria).
Then, the ratio between correct/incorrect "stored" responses represent the "accuracy", according to which the next trial is displayed. This is needed as, if participants are very inaccurate, we need to display a trial that presents the circle with an higher constrast (more visible). Instead, if they are very accurate, we need to display a trial which presents the circle with a lower contrast (less visible). All this is needed because we want to reach a certain level of performance for each subject.
I hope that this would be possible: here is the code
Thank you very much to all of you!!
Eleonora
<shape red_circle>
/ color = (180,180,180)
/ position = (50%,50%)
/ shape = circle
/size=(10%, 10%)
</shape>
<shape black_circle>
/ color = (185,185,185)
/ position = (50%,50%)
/ shape = circle
/ size=(10%, 10%)
</shape>
<shape blank>
/ color = (192,192,192)
/ position = (50%,50%)
/ shape = rectangle
/size=(30%, 30%)
</shape>
<trial blank>
/stimulusframes=[1=blank]
/ trialduration = 3000
</trial>
<text cross>
/items=("+")
/position = (50%, 50%)
</text>
<picture checker>
/items=("scacchieracc.png")
/ position = (50%, 50%)
/ size = (30%, 30%)
</picture>
<trial fixate>
/ stimulusframes = [1=cross]
/ trialduration = 2000
</trial>
<values values>
/timeofresponse=""
/spacebarpresscount =""
/accuracy = ""
</values>
<trial acc>
/pretrialpause = 1000
/stimulustimes=[
0=red_circle, checker;
1007=red_circle, checker;
2082=red_circle, checker;
3220=red_circle, checker;
4399=red_circle, checker;
5570=red_circle, checker;
6708=red_circle, checker;
7936=red_circle, checker;
9059=red_circle, checker;
10259=red_circle, checker;
11460=red_circle, checker;
12633=red_circle, checker;
13893=red_circle, checker;
15069=red_circle, checker;
16284=red_circle, checker;
17449=red_circle, checker;
18591=red_circle, checker;
19795=red_circle, checker;
20915=red_circle, checker;
22149=red_circle, checker;
23244=red_circle, checker;
24398=red_circle, checker;
25567=red_circle, checker;
26690=red_circle, checker;
27885=red_circle, checker;
28998=red_circle, checker;
30208=red_circle, checker;
31421=red_circle, checker;
32539=red_circle, checker;
33702=red_circle, checker;
34789=red_circle, checker;
35849=red_circle, checker;
36972=red_circle, checker;
38018=red_circle, checker;
39172=red_circle, checker;
40341=red_circle, checker;
41437=red_circle, checker;
42572=red_circle, checker;
43681=red_circle, checker;
44758=red_circle, checker;
45918=red_circle, checker;
46995=red_circle, checker;
48090=red_circle, checker;
50=black_circle, checker;
1057=black_circle, checker;
2132=black_circle, checker;
3270=black_circle, checker;
4449=black_circle, checker;
5620=black_circle, checker;
6758=black_circle, checker;
7986=black_circle, checker;
9109=black_circle, checker;
10309=black_circle, checker;
11510=black_circle, checker;
12683=black_circle, checker;
13943=black_circle, checker;
15119=black_circle, checker;
16334=black_circle, checker;
17499=black_circle, checker;
18641=black_circle, checker;
19845=black_circle, checker;
20965=black_circle, checker;
22199=black_circle, checker;
23294=black_circle, checker;
24448=black_circle, checker;
25617=black_circle, checker;
26740=black_circle, checker;
27935=black_circle, checker;
29048=black_circle, checker;
30258=black_circle, checker;
31471=black_circle, checker;
32589=black_circle, checker;
33752=black_circle, checker;
34839=black_circle, checker;
35899=black_circle, checker;
37022=black_circle, checker;
38068=black_circle, checker;
39222=black_circle, checker;
40391=black_circle, checker;
41487=black_circle, checker;
42622=black_circle, checker;
43731=black_circle, checker;
44808=black_circle, checker;
45968=black_circle, checker;
47045=black_circle, checker;
48140=black_circle, checker;
]
/ trialduration = 48140+1000
/ inputdevice = keyboard
/ beginresponsetime = -1
/ responseinterrupt = trial
/ validresponse = (-57, 0)
/ correctresponse = (0)
/ showmousecursor = false
/ isvalidresponse = [if(trial.acc.response==57){values.spacebarpresscount += 1; values.timeofresponse=concat(concat(values.timeofresponse, trial.acc.latency),","); false}; ]
</trial>
<block pre>
/ trials = [1=fixate; 2=blank]
</block>
<block acc>
/ trials = [1=acc]
</block>
<expt >
/blocks=[
1=pre;2=acc;break;3=acc
]
</expt>
<data>
/ columns = [date,time,group,subject, display.refreshrate, display.canvaswidth, display.canvasheight, trialduration, values.timeofresponse,values.spacebarpresscount
shape.black_circle.stimulusonset.1
shape.black_circle.stimulusonset.2
shape.black_circle.stimulusonset.3
shape.black_circle.stimulusonset.4
shape.black_circle.stimulusonset.5
shape.black_circle.stimulusonset.6
shape.black_circle.stimulusonset.7
shape.black_circle.stimulusonset.8
shape.black_circle.stimulusonset.9
shape.black_circle.stimulusonset.10
shape.black_circle.stimulusonset.11
shape.black_circle.stimulusonset.12
shape.black_circle.stimulusonset.13
shape.black_circle.stimulusonset.14
shape.black_circle.stimulusonset.15
shape.black_circle.stimulusonset.16
shape.black_circle.stimulusonset.17
shape.black_circle.stimulusonset.18
shape.black_circle.stimulusonset.19
shape.black_circle.stimulusonset.20
shape.black_circle.stimulusonset.21
shape.black_circle.stimulusonset.22
shape.black_circle.stimulusonset.23
shape.black_circle.stimulusonset.24
shape.black_circle.stimulusonset.25
shape.black_circle.stimulusonset.26
shape.black_circle.stimulusonset.27
shape.black_circle.stimulusonset.28
shape.black_circle.stimulusonset.29
shape.black_circle.stimulusonset.30
shape.black_circle.stimulusonset.31
shape.black_circle.stimulusonset.32
shape.black_circle.stimulusonset.33
shape.black_circle.stimulusonset.34
shape.black_circle.stimulusonset.35
shape.black_circle.stimulusonset.36
shape.black_circle.stimulusonset.37
shape.black_circle.stimulusonset.38
shape.black_circle.stimulusonset.39
shape.black_circle.stimulusonset.40
shape.black_circle.stimulusonset.41
shape.black_circle.stimulusonset.42
shape.black_circle.stimulusonset.43
shape.red_circle.stimulusonset.1
shape.red_circle.stimulusonset.2
shape.red_circle.stimulusonset.3
shape.red_circle.stimulusonset.4
shape.red_circle.stimulusonset.5
shape.red_circle.stimulusonset.6
shape.red_circle.stimulusonset.7
shape.red_circle.stimulusonset.8
shape.red_circle.stimulusonset.9
shape.red_circle.stimulusonset.10
shape.red_circle.stimulusonset.11
shape.red_circle.stimulusonset.12
shape.red_circle.stimulusonset.13
shape.red_circle.stimulusonset.14
shape.red_circle.stimulusonset.15
shape.red_circle.stimulusonset.16
shape.red_circle.stimulusonset.17
shape.red_circle.stimulusonset.18
shape.red_circle.stimulusonset.19
shape.red_circle.stimulusonset.20
shape.red_circle.stimulusonset.21
shape.red_circle.stimulusonset.22
shape.red_circle.stimulusonset.23
shape.red_circle.stimulusonset.24
shape.red_circle.stimulusonset.25
shape.red_circle.stimulusonset.26
shape.red_circle.stimulusonset.27
shape.red_circle.stimulusonset.28
shape.red_circle.stimulusonset.29
shape.red_circle.stimulusonset.30
shape.red_circle.stimulusonset.31
shape.red_circle.stimulusonset.32
shape.red_circle.stimulusonset.33
shape.red_circle.stimulusonset.34
shape.red_circle.stimulusonset.35
shape.red_circle.stimulusonset.36
shape.red_circle.stimulusonset.37
shape.red_circle.stimulusonset.38
shape.red_circle.stimulusonset.39
shape.red_circle.stimulusonset.40
shape.red_circle.stimulusonset.41
shape.red_circle.stimulusonset.42
shape.red_circle.stimulusonset.43
]
</data>
<defaults>
/ screencolor = (192,192,192)
/ txbgcolor = (192,192,192)
/ txcolor = white
/ fontstyle = ("Trebuchet MS", 3.11%, false, false, false, false, 5, 1)
</defaults>