COMPUTE! ISSUE 19 / DECEMBER 1981 / PAGE 129

 Memory Recall Test V. NasserBirmingham, England If a human subject is exposed to a set of random numbers or letters for a short span of time, the number of items recalled is generally about 7 ± 2 items. Theories abound as to the capacity for immediate memory. Obviously words/letters/numbers that are meaningful will be more likely to be remembered than meaningless items. Also, if numbers can be organized in a meaningful way, then the probability of accurate recall is greater. It is possible, with training, to increase one's immediate memory span by a considerable amount. Let me give a typical example. Exposed to the numbers: 162536496481 (and providing one recognizes that each pair of digits is the square of consecutive natural numbers from 4 to 9) then one only has to remember six "chunks," but will nevertheless seem to remember 12 numbers. However, if the numbers are random, obviously one may not always be able to organize the digits in a meaningful way. My program works in the following way: it asks the subject how many numbers he or she wants to recall. When the subject enters the required items, the program will display the appropriate number of random numbers for a certain time. This exposure time incidentally, is a function of the number of numbers chosen. So that three numbers will be exposed for a much shorter time than ten numbers. After the exposure of random numbers, the screen is automatically cleared and the subject is asked to input the numbers in the sequence originally shown. The program will terminate upon the first erroneous digit input and give the correct answers. So having explained a bit about the psychology of immediate memory and presented a program to test your memory span, what use can this program be put to? Under the influence of alcohol or sedative drugs the memory span drops in proportion to the amount consumed. Further, in certain condition of brain damage it is not possible to remember more than two or three digits. Thus it has diagnostic possibilities. But more interesting, in my opinion, is the way the program encourages you to remember. If one starts at a low level the initial successes create the automatic reinforcements necessary to increase one's memory span. This is remarkable since the numbers displayed are random and there is very little chance of organizing them in any meaningful way. It can be used for any age group from nine years onwards. The program is both simple and absorbing. It can be adapted for any computer using BASIC, but was specifically written for the Superboard II. 1 FOR T=l TO 32:PRINT:NEXT 2 PRINT "MEMORY RECALL TEST" 3 PRINT:PRINT:PRINT 8 CLEAR 9 PRINT " TYPE NUMBER OF NUMBERS TO BE RECALLED" 10 INPUT P 15 DIM A(P) 16 FOR I=1 TO 32:PRINT:NEXT 20 FOR N=1 TO P 25 A(N)=INT(RND(1)*10) 26 PRINT TAB (2); 30 PRINT A(N);:IF P0S(l)>18 THEN PRINT: PRINT 50 NEXT 55 FOR X=l TO 500*N:NEXT X 56 FOR T=l TO 32:PRINT:NEXT 60 FOR N=l TO P 70 INPUT Y 80 IF Y<>A(N) THEN 100 85 NEXT N 90 PRINT " WELL DONE " 95 GOTO 8 100 PRINT " INCORRECT " 110 PRINT " THE CORRECT ANSWERS ARE " 120 FOR N=1 TO P 125 PRINT TAB(2); 130 PRINT A(N);:IF POS(1)>18 THEN PRINT: PRINT 135 NEXT N 136 PRINT:PRINT:PRINT 140 GOTO 8 READY.