<ep> <fd 1> <d 89> <s 1>1 <cr>
<t 1500> <id digitalVOX>2 <id RecordVocal 03b, 15003c>3a <id keyboard>
<dbc 210210210> <dfs
36> <vm 1024,768,768,16,60> <nfb> <eop>
$4
! Verbal Stroop task;
! Includes 2 color naming and 1 word reading block;
! 9 trials per block, scrambled within block;
! Brief timed break between blocks 1 & 2, paused break between
blocks 2 & 3;
! Item number ABCDEF;
! A=Task (1=Color name,2=Word read);
! B=condition (1=congruent, 2=neutral, 3=incongruent);
! C=block
(1- 3);
! D= item number in condition/block;
! last edited on 11-19-05;
0 "Press SPACEBAR to start";
0 <d 10>4<ln -1>5 "NAME INK COLOR
as quickly as possible!", <ln
1>5 "IGNORE the WORD."<ms%
5000>/c6;
0 <d 10><% 59> /c;
$7
+1111 * "RED8" <% 30>
/<% 60>9;
+1112 * "GREEN8" <% 30>
/<% 60>;
+1113 * "BLUE8" <% 30>
/<% 60>;
+1211 * "TOE" <% 30> /<% 60>;
+1212 * "HAND" <% 30> /<% 60>;
+1213 * "WRIST" <% 30> /<% 60>;
+1311 * "GREEN" <% 30> /<% 60>;
+1312 * "RED" <% 30> /<% 60>;
+1313 * "BLUE" <% 30> /<% 60>;
\10
$
0 <ln -1> "Have a
Break", <ln 1> "Experiment will
RESTART in 5 seconds"<ms% 5000>/c;
0 <d 10>"Remember to NAME INK COLOR"<ms%
5000>/c;
0 <d 10><% 59>/c;
$
+1121 * "RED" <% 30> /<% 60>;
+1122 * "GREEN" <% 30> /<% 60>;
+1123 * "BLUE" <% 30> /<% 60>;
+1221 * "TOE" <% 30> /<% 60>;
+1222 * "HAND" <% 30> /<% 60>;
+1223 * "WRIST" <% 30> /<% 60>;
+1321 * "GREEN" <% 30> /<% 60>;
+1322 * "RED" <% 30> /<% 60>;
+1323 * "BLUE" <% 30> /<% 60>;
\
$
0 <ln -1> "Have a
Break", <ln 1> "RA will provide new
task instructions";
0 <d 10><ln -1> "READ
WORD as quickly as possible!", <ln 1> "IGNORE the INK COLOR."<ms% 5000>/c;
0 <d 10><% 59> /c;
$
+2131 * "RED" <% 30> /<% 60>;
+2132 * "GREEN" <% 30> /<% 60>;
+2133 * "BLUE" <% 30> /<% 60>;
+2231 * "TOE" <% 30> /<% 60>;
+2232 * "HAND" <% 30> /<% 60>;
+2233 * "WRIST" <% 30> /<% 60>;
+2331 * "GREEN" <% 30> /<% 60>;
+2332 * "RED" <% 30> /<% 60>;
+2333 * "BLUE" <% 30> /<% 60>;
\
$
0 <d 10><ln -1> "Experiment
Complete!", <ln
1> "Thank you for participating.";
$
NOTES:
1: S/Scramble is
used to randomize the order of item presentation. N1 is the blocksize,
which is the number of items (if no grouping keyword is used) or groups (if
<G> keyword is used) in a block. DMDX
will scramble items in blocks of N1 and then scramble those blocks relative to
each other. In our example, we use a blocksize of 1 so all individual items are scrambled
relative to each other.
2: Digital VOX is another
device DMDX is used to gather response times to verbal input. If used, the RT for a verbal response will be
measured from clockon to the point where the
verbalization exceeds some threshold intensity.
This intensity threshold is set by selecting the DMDX Menu item File:Test VOX. Have
the participant sit quietly for a few moments.
Set threshold above this “quiet” level.
Then have the participant count to ten.
Set threshold well below the lowest peak intensity when counting.
3a: RecordVocal
is another device that records from the default audio capture device to a
file. RecordVocal
will create a WAV file for every clockon (*). The name of the WAV file will be the itemfile name + the subject number + the item number. WAV files will be saved in the same folder
with the itemfile.
3b: N1 changes the length of
data recorded to be N1 milliseconds longer than the trigger provided by the DigitalVox device. 3c N2 determines how much
overrun protection DMDX allows. By default, N2=50. If you want to record the full window from clockon to timeout, you can specify N1=0 and N2= Timeout
value (e.g., in our example, 1500ms recordings, starting with clockon). Do not use
RecordVocal without any parameters (legacy mode) as
there are problems with legacy mode on XP systems and above.
4: D/Delay can be
used in an item too (as
opposed to on the parameter line, it's more typical usage) if you want to vary
delays across items. If used in an item,
it must be in the first frame and likely should be the first switch keyword
listed. It will override the default
delay specified in the parameter line and specifies the delay for just that
item (not the next one), it does not affect the delay specified in the
parameter line and does not affect any other item.
5:
LN/Line controls vertical orientation of text on the screen. The default row for text display is considered row 0 in the
middle of the screen, the rows above are negative and the rows below
positive. You can present multiple rows
by separating text with a comma as in our example.
6: C/Continue is used in any frame in an
item. The item continues on to the next
without waiting for a request. This will
even override the function of message items (i.e., items that begin with 0). We use this most commonly on message items
for timed instructions. In our example
above, instruction items are presented for approximately 5000ms.
7: $ is
used with scramble to allow some sections in the itemfile
to remain in a fixed absolute position within the file. Any material enclosed within a pair of $
symbols will not be scrambled, and the other of this segment relative to the
rest of the file will remain constant.
Note: Scramble programs do not respect any of the internal
conventions of an ITM file, except for the parameters on the first line and the
item delimiter (;). Thus the task instructions, the practice items and the
final end-of-experiment message will appear at unpredictable locations unless
they are enclosed within $ delimiters.
8: WYSIWYG is an acronym
for What You See Is What You Get. What you see on the screen during editing is
exactly what will be seen by the participant. This is one method to control
color and size of text. WYSIWYG is
overridden if you specific a writing color in the parameter line.
9: This additional blank frame is added to
account for the time out of 1500ms.
Remember that to maintain a fixed delay between items independent of
participants response times, you must make sure that the time between the clockon (*) and the end of the item > the time
out value for that item. In this case,
the time out is 1500ms. The stimulus is
presented for 30 ticks. Therefore we add
a blank frame of 60 ticks to the end of the item (90 ticks at 60Hz is 1500ms).
10:Backslashes are used with the
scramble keyword to create, in essence, separate item files to scramble. This allows use to keep the order of these
“separate” itemfiles constant. In our example, we have three separate sets
of items. Each of these sets of items
includes 9 items and we scramble in blocks of 9 (from the N1 is the scramble
keyword). This means that items within
each set of 9 will be scrambled relative to each other, but the first 9 will
always precede the second 9, which precedes the third 9. If instead we put all 27 items together
without the backslash and still scrambled in blocks of 9, it would scramble
within blocks of 9 first, but then scramble the order of the three blocks of 9.
Created by
Tattiya Kliengklom
Last
edited on