Difference between revisions of "CRP Tutorial"
From Computational Memory Lab
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− | The easiest way to construct a lag CRP is from a recalls matrix, which shows the serial position of recalled words. The simplest way to do that is to loop over trials/lists: | + | The easiest way to construct a lag CRP is from a <tt>recalls</tt> matrix, which shows the serial position of recalled words. The simplest way to do that is to loop over trials/lists: |
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Note two important things: | Note two important things: | ||
− | # Intrusions are not included in the recalls matrix. | + | # '''Intrusions''' (recalls that were not presented in the just-seen list) are not included in the <tt>recalls</tt> matrix above. For example, notice in the third row (i.e., third trial) of <tt>rec</tt> matrix that the last item recalled is 1591. Word 1591 was presented in trial 2, not trial 3; this is an example of a '''prior-list intrusion'''. The corresponding spot in the <tt>recalls</tt> matrix is zero. (For the purposes of constructing a lag CRP, we can ignore all intrusions, so this is ok.) |
− | # In-list repetitions are ''not'' noted and show up in the recalls matrix normally. Notice that in the last trial, word 87 is recalled twice, so serial position 15 appears twice in the last row of the recalls matrix. We '''will''' have to take care of that before calculating the lag CRP. | + | # '''In-list repetitions''' are ''not'' noted and show up in the <tt>recalls</tt> matrix normally. Notice that in the last trial, word 87 is recalled twice, so serial position 15 appears twice in the last row of the <tt>recalls</tt> matrix. We '''will''' have to take care of that before calculating the lag CRP. |
Revision as of 20:32, 19 March 2013
pres = [1062 219 779 148 668 1458 694 1637 475 1433 912 1416 785 1411 701 969; 1175 788 653 1031 1410 184 1134 993 152 313 1033 1591 652 1115 1184 1531; 329 605 414 1614 852 950 1105 10 1144 459 856 455 1178 277 1415 1118; 843 1173 1067 46 1435 1561 1202 30 270 493 815 102 233 796 500 753; 1044 372 556 1600 685 1598 409 989 1326 100 757 94 1491 1398 56 1261; 257 1454 315 1596 1400 1578 840 1069 1294 1254 572 758 1052 620 1230 380; 546 811 252 1093 147 241 589 1351 1373 1446 1621 310 920 188 22 339; 1179 1402 1468 581 1629 647 710 207 1313 1627 378 397 400 515 1579 1038; 1107 410 206 1413 441 930 1439 975 242 109 1257 1193 535 1471 122 132; 1427 555 949 1204 116 540 479 582 1386 888 258 1342 1198 574 87 1008];
rec = [ 701 969 475 785 1411 1062 219 0 0 0 0 0 0 0 0 0; 1531 313 1033 993 1134 0 0 0 0 0 0 0 0 0 0 0; 605 414 950 852 277 1415 329 455 1591 0 0 0 0 0 0 0; 500 753 843 1173 46 815 0 0 0 0 0 0 0 0 0 0; 1261 1491 409 989 1044 372 556 1598 757 0 0 0 0 0 0 0; 380 620 1052 315 1596 572 1294 758 1254 0 0 0 0 0 0 0; 339 22 188 1373 1446 589 0 0 0 0 0 0 0 0 0 0; 1038 515 1579 378 0 0 0 0 0 0 0 0 0 0 0 0; 132 1471 1107 1193 1257 410 535 109 1439 930 0 0 0 0 0 0; 87 1342 1008 574 1471 888 479 540 87 116 0 0 0 0 0 0];
The easiest way to construct a lag CRP is from a recalls matrix, which shows the serial position of recalled words. The simplest way to do that is to loop over trials/lists:
nList = size(pres,1); % Number of lists/trials; equal to number of rows in "pres"
listLength = size(pres,2); % Number of presented items per list;
% equal to number of columns in "pres"
recalls = nan(nList,listLength); % Preallocate with NaNs for speed
for i = 1:10 % Loop over trials
[~,recalls(i,:)] = ismember(rec(i,:),pres(i,:)); % Find each recalled item in the
% presented list and report its
% (serial) position
end
recalls % Print the "recalls" matrix to the command window
Which should produce the following output:
recalls = 15 16 9 13 14 1 2 0 0 0 0 0 0 0 0 0 16 10 11 8 7 0 0 0 0 0 0 0 0 0 0 0 2 3 6 5 14 15 1 12 0 0 0 0 0 0 0 0 15 16 1 2 4 11 0 0 0 0 0 0 0 0 0 0 16 13 7 8 1 2 3 6 11 0 0 0 0 0 0 0 16 14 13 3 4 11 9 12 10 0 0 0 0 0 0 0 16 15 14 9 10 7 0 0 0 0 0 0 0 0 0 0 16 14 15 11 0 0 0 0 0 0 0 0 0 0 0 0 16 14 1 12 11 2 13 10 7 6 0 0 0 0 0 0 15 12 16 14 0 10 7 6 15 5 0 0 0 0 0 0
Remember that the recalls matrix shows the serial position (i.e., position in the presentation list) of each item recalled. Zeros indicate either no word recalled, or an intrusion (see point 1 below).
Note two important things:
- Intrusions (recalls that were not presented in the just-seen list) are not included in the recalls matrix above. For example, notice in the third row (i.e., third trial) of rec matrix that the last item recalled is 1591. Word 1591 was presented in trial 2, not trial 3; this is an example of a prior-list intrusion. The corresponding spot in the recalls matrix is zero. (For the purposes of constructing a lag CRP, we can ignore all intrusions, so this is ok.)
- In-list repetitions are not noted and show up in the recalls matrix normally. Notice that in the last trial, word 87 is recalled twice, so serial position 15 appears twice in the last row of the recalls matrix. We will have to take care of that before calculating the lag CRP.