PO6 Comunicación de los objetivos y de las aspiraciones de la gerencia

The next set of tasks sought to determ ine w hether the com prehension of num bers in S.F. had been preserved. These tasks, devised to test the arabic and verbal n u m erals com prehension m echanism s, req u ire d the elab o ratio n of a quantity representation w ithout involving the num ber p roduction system s.

M a g n itu d e Com parison. In the m ag n itu d e com parison tasks S.F. was asked to ju d g e which of two num bers was larger.

M a te r ia l. The sam e set of 190 pairs of num bers w as u sed in all three m ag n itu d e com parison tasks. The criteria for the subdivision an d the detailed contents for each stim ulus subgroup are given in Table 3.12. The tw o num bers in the pair h ad the same num ber of digits and only one digit was varied.

(insert table 3.12 about here)

P ro ced u re. Three different m agnitude com parison tasks w ere perform ed. In the first one the pairs w ere arabic num erals, in the second one spoken num ber nam es, an d in the third one one of these num bers w as spoken by the exam iner w hile the other w as an arabic num eral presented on a single card.

Visual M agnitude Comparison. In this task, S.F. was asked to "circle" the larger of tw o arabic num erals. 40 pairs of arabic num erals w ere ty p ed in a random o rd er in a column. Three different pages w ere used: the first an d the second pages each contained a set of 40 arabic num erals w hile the th ird one co n tain ed 30 arabic num erals. S.F. re sp o n d ed p ro m p tly to all item s. H is percentage of correct answers was 98%.

A uditory M agnitude Comparison. In this task, S.F. was asked to rep eat the larger of the tw o num ber names spoken by the examiner. S.F. resp o n d ed rapidly and correctly to all items (100% correct answers).

V isu a l/A u d ito ry M agnitude Comparison. In this task, one n u m b er was spoken by the exam iner while the other w as an arabic num eral p resen ted on a single card. S.F. w as asked to point to the arabic num eral only if it w as a larger n u m b er th a n the spoken num ber nam e given by the exam iner. A gain S.F.'s perform ance w as well preserved: 96% of his responses w ere correct.

Table 3.12

The contents of the m agnitude com parison battery

ips Stimulus type (Pairs) Exam ples N o.

1 single num ber 1 ,2 ,3 ,4 ,5 10

2t 2 num bers from 10 to 19 11,12,13,14 10

2a 2 num bers from 20 to 90 20,30,40,50 10

2b other tw o num bers 46,27,83,91 10

3a 3 num bers ending in zeros 100,200,300 10

3b 3 num bers w ithout internal zeros 364,670,940 10 3c 3 num bers w ith internal zeros 107,502,806 10

4a 4 num bers ending in zeros 1000,2000 10

4b 4 num bers w ithout internal zeros 1850,8734 10 4c 4 num bers w ith internal zeros 5019,2007 10

5a 5 num bers ending in zeros 30000,40000 10

5b 5 num bers w ithout internal zeros 56780,14900 10 5c 5 num bers w ith internal zeros 89705,10500 10

6a 6 num bers ending in zeros 500000,600000 10 6b 6 num bers w ithout internal zeros 142380,795800 10 6c 6 num bers w ith internal zeros 180924,670340 10

7a 7 num bers ending in zeros 7000000 10

7b 7 num bers w ithout internal zeros 4500000 10 7c 7 num bers w ith internal zeros 2870940 10

Black dots magnitude comparison. In this task the p a tien t w as asked to com pare the num erosity of tw o patterns of different-sized black dots w hich w ere random ly arranged on pairs of sheets of w hite paper. N o explicit know ledge of

num ber nam es was required for this task though correct perform ance needed an u n d erstan d in g of num ber values. The sam e m aterial used w ith the p a tien t C.G. was ad o p ted (see chapter 2). There w ere 20 pairs w here each p attern h a d 9 or fewer dots and 20 pairs of dot patterns w ith 10 to 99 dots. S.F.'s perform ance was correct for all of the pairs. Response latencies w ere not recorded on this task, but S.F. appeared to respond at a norm al speed.

S u m m a r y . The results o b tain ed in the n u m b er co m p reh en sio n tasks indicated that S.F.'s ability to com prehend arabic and verbal num erals is largely intact. H is difficulty in reading num erals aloud therefore can not be attributed to an im paired com prehension of the stim ulus num ber.

3.32c T ests of N um ber Production

3.32c I Tests of verbal num ber production.

McCloskey et al. assum ed that the verbal num ber production m echanism s are responsible for retrieving spoken n u m ber nam es n o t only w hen reading aloud arabic num erals but in all tasks requiring the verbal production of num ber nam es. If S.F.'s im p airm en t in read in g alo u d arabic n u m era l reflects the m alfu n ctio n in g of the verbal n u m b er p ro d u c tio n m ech an ism s w e w o u ld therefore expect im paired perform ance in any tasks requiring verbal num eral production. It w as already show n that S.F.'s reading of w ritten n u m ber names w as good. The next set of tasks assessed w hether S.F. suffered from a m ore general difficulty in num ber production.

Cardinal facts. Know ledge of exact cardinal num ber facts w as assessed by m eans of general know ledge questions that everyone m ight be expected to get right (e.g. H ow m any days in a year?). 20 questions, requiring the production from 2 to 4 digit spoken num ber names, were given to S.F. and his answ ers were all correct.

Personal N um ber Facts. The p a tien t w as asked 20 q u estio n s tap p in g personal num erical inform ation (e.g. year of birth) and requiring the production from 2 to 4 d ig it spoken num ber nam es. S.F. resp o n d ed correctly to all the questions.

Non personal Number Facts. The patien t was asked 20 questions tapping num erical inform ation generally know n by all people of a sim ilar background

(e.g. year of America's discovery) an d requiring the production of 4 digit spoken num ber names. Again his perform ance was flawless on all the items.

Num erical Cognitive Estimates. Follow ing Shallice and Evans (1978), 15 num erical estim ation questions w ere devised. H ere ap p ro x im ate n um erical values are req u ired (e.g. n u m ber of passengers in a train com partm ent). His perform ance w as again flawless.

Reciting number names. S.F. w as asked to count forw ard until sto p p ed by the exam iner. Three series (counting in units of ones, tw os, an d threes) w ere produced orally. After specifying the sequence type, the exam iner indicated orally the first n u m b er nam e. The p a tie n t w as sto p p e d after he h a d p ro d u c e d approxim ately 10 num bers for each sequence. In order to detect if S.F. w as able to enter the num ber nam e sequence at any point, the experim enter indicated orally the follow ing first num ber names:

1 and 1,900 for the counting in units, 2 and 240 for the counting in twos 3 and 3,300 for the counting in threes.

The patient's perform ance was flawless in all the sequences and he d id not use finger counting.

"W/iat comes next". Presentation of the num ber nam e w as auditory. The experim enter gave a num ber nam e and S.F. was asked to produce the next one. Two stim uli from each of the 19 subgroups used in the reading aloud task w ere presented to S.F. The patient was able to answ er 37 out of the 38 questions.

S u m m a r y . The results o b tain ed in all of the above tasks show clear evidence of a well preserved ability to produce the appropriate spoken num ber nam es in tasks that did not require the reading of arabic num erals.

N um ber Repetition Task. The sam e b a ttery of n u m b ers u se d for the reading aloud tasks was adm inistered as a num ber repetition task. The exam iner read each n u m b er once, and the p a tien t w as asked to rep e at the stim ulus im m ediately after the exam iner had finished.

R e s u lts . The p atien t was able to correctly rep eat 379 o u t of 385 (98%) num bers. This perform ance was clearly b etter than his perform ance in reading aloud arabic num erals (45% correct answ ers). The 6 w rong responses given by S.F. consisted of 2 syntactic and 4 lexical errors.

S u m m ary . These results confirm those obtained in the previous task; S.F. did n o t have a general difficulty in producing spoken num ber names.