Journal of Gerontology 1976, Vol. 31, No. 3, 327-332
Cognitive Strategy Training and Intellectual Performance in the Elderly1
Reduced intellectual performance in the elderly was conceptualized as an experiential deficit that can be reversed by training relevant component skills. Sixty female elderly subjects (ages 63 to 95) participated in three phases of the experiment: Training, Immediate Posttest, and Delayed Posttest. Training was geared at strengthening covert self-monitoring strategies in complex reasoning problems, and training effects were evaluated both on the training and a transfer task. Results showed raised performance in the training conditions, transfer effects, and maintenance of training and transfer effects over 2 weeks. Implications for theories of adult intelligence are discussed.
in the area of adult intellectual RESEARCH redevelopment and aging has indicated, in
general, age-associated performance deficits when young and elderly samples are compared (Baltes & Labouvie, 1973; Riegel, 1973). Usually these differences are interpreted in terms of a maturational model emphasizing biological decrement. However, recent criticisms have called for a reinterpretation of conventional, maturational, decrement-oriented views of aging for the following reasons: (a) causal relationships have been implied from primarily psychometric-descriptive and correlational evidence (Baltes & Labouvie, 1973); (b) the poor covariance between biological status and intelligence in healthy elderly suggests that biological status, at least in the healthy elderly, is a necessary but not sufficient condition for adequate intellectual performance (Hertzog, Gribbin, & Schaie, 1975; Riegel & Riegel, 1972; Wang, 1973); and (c) the strong impact of sociocultural variables as indicated by cohortrelated and other experiential factors, such as life complexity (Schaie & Gribbin, 1975), suggests that, at least in healthy elderly, a major share in cognitive performance is accounted for by experiential parameters (Schaie, 1975; Schaie & Labouvie-Vief, 1974). Thus, some authors have argued for a stronger emphasis on environmental and experiential factors (Baltes & Labouvie, 1973; Labouvie-Vief, 'The current research was supported by a grant from the National Institutes of Health (1-R01, MD-07867-01). The authors wish to thank Mary Gander and Margaret Semrud for their help in carrying out the project. •Univ. of Wisconsin, Dept. of Educational Psychology, Madison 53706.
Hoyer, Baltes, & Baltes, 1974). This view calls for a de-emphasis on conceptualizations of poor performance as a competence deficit and an emphasis on exploration of parameters linked to performance deficits. The present study conceptualized reduced intellectual performance as an experiential deficit that can be reversed by concentrating on the training of certain component skills. According to Baltes and Labouvie (1973), these component behaviors may either be directly intellectual, or they may be nonintellectual but nevertheless performance-related. The first of these classes relates to skills and strategies that are cognitive in nature and have in general been discussed in terms of the elderly individual's failure to use effective verbal mediators and planning strategies in solving tasks (Botwinick, 1967; Goulet, 1973; Kausler, 1970). The second group is more general and comprises such skills as ways of coping with test-anxiety, frustration, and failure; this class of skills thus far has not been investigated in relation to intellectual performance, although its major importance has been noted in learning tasks (Eisdorfer, Nowlin, & Wilkie, 1970). Actual research manipulating both classes of factors has been rare thus far, but has produced promising results (Crovitz, 1966; Hoyer, Labouvie, & Baltes, 1973; Meichenbaum, 1974). The present study, therefore, examined the effect of strategy training on intellectual performance in the elderly. In addition, this research attempts to deal with two criticisms often raised in relation to intervention-oriented 327
Downloaded from http://geronj.oxfordjournals.org/ at University of Iowa Libraries/Serials Acquisitions on July 23, 2015
Gisela Labouvie-Vief, PhD,2 and Judith N. Gonda, MA
328
LABOUVIE- VIEFAND GONDA
METHOD
Subjects A sample of 60 females was recruited from a Madison, Wisconsin, public housing development for elderly people. Subjects were randomly selected from the total population of the housing development and asked to volunteer for the research. Each participant received a remuneration of $9.00 on completion of the second post-test. Subjects ranged in age from 63 to 95 with a mean age of 76 years. The subjects were randomly assigned to one of four training groups of 15 each. Procedure The study consisted of three phases: Training, Immediate Posttest, and Delayed Posttest. Four training groups were involved at each phase: two instructional groups, Cognitive Training and Anxiety Training, and two control groups, Unspecific Training and No Training. The training was given on a set of inductive reasoning problems — items taken from a parallel form of the Immediate Posttest, the Letter Sets Test (French, Ekstrom, & Price, 1963). Immediately following the training procedure, the effect of the different modes of training on the Training Task were assessed during Immediate Posttest. At the same time, in order to determine any potential generalized effects of the training procedure, a Transfer Test, the Raven's Progressive Matrices (Raven, 1958), consisting of a different type of inductive reasoning problems was administered. Delayed Posttest consisted in the administration of the Training and Transfer Test approximately 2 weeks after Immediate Post-
test. The interval between the two sessions averaged 14 days (range: 10-28). Subjects were tested in their homes by two female graduate students. Training Task According to current theorizing in the area of intellectual abilities, different intellectual abilities differ markedly in the extent to which they are trainable (Horn, 1970), depending upon the degree to which they represent the effects either of acculturation or of the biological-maturational well-being of the individual. Since the purpose of the present study was to explore the utility of an environmental rather than biological deficit interpretation of aging decrements, the strongest test was considered to be offered by a task that traditionally had been interpreted to indicate the degree ef biological decrement in the elderly. In CattellY (1963) and Horn's (1970) framework of fluid and crystallized intelligence, this would be true of fluid intelligence, which is marked best by tests of inductive reasoning (Horn, 1970). A test of inductive reasoning, the Letter Sets Test, was therefore chosen as the training task. This test was obtained from the French et al. (1963) Kit of Reference Tests for Cognitive Factors, a careful compilation of reference tests that is based on extensive factor-analytic structuring of the ability domain. The Letter Sets Test presents the subjects with five sets of four letters in each item. The task is to find which rule relates the four letters within each to each other, and to mark the one which does not fit the rule. Transfer Task A task related to the Training Task was included to provide for a more powerful estimate of the generalizability of the training procedure. The Transfer Test, Raven's Standard Progressive Matrices, is, like the Letter Sets Test, a marker of inductive reasoning. Training Procedure In general, the training procedure was aimed at the modification of subjects' verbal selfmonitoring during task performance. It was hypothesized that elderly subjects spontaneously generate a high frequency of task-interfering self-instructional statements, thus resulting in ineffective self-regulation of behavior. This hypothesis was tested by the comparison between four training groups. The first two of these (In-
Downloaded from http://geronj.oxfordjournals.org/ at University of Iowa Libraries/Serials Acquisitions on July 23, 2015
research. The first of these relates to the problem that training, although facilitative, may be highly task-specific and thus may not really represent a broad class of strategies that will raise intellectual behavior, in general (Kohlberg, 1968). To counter this objection the present study examined the effects of training not only on the training task itself, but on other tasks (transfer tasks) as well. The second problem similarly concerns the generalizability of training effects, but relates to their transitory rather than narrow nature. Consequently, the proposed research also included an examination of the long-term facilitative effects of the training.
TRAINING AND INTELLIGENCE IN THE ELDERL Y
329
Go slowly, keep trying. Don't get stuck, try another. Now I know how it works. Good, that's correct. I'm half the way through, already.
Posttests Both the Immediate and Delayed Posttests followed the same procedure, consisting in the
Downloaded from http://geronj.oxfordjournals.org/ at University of Iowa Libraries/Serials Acquisitions on July 23, 2015
structional Training groups) constituted the of coping with failure, and self-approval rather training groups proper (Cognitive Training, than criticism. Examples of both classes of Anxiety Training). Unspecific Training served statements are given in Table 1. to compare the effectiveness of the InTraining was done in individual sessions. For structional Training with effects of test each session, a special training booklet was profamiliarity, per se. Thus this condition served vided consisting of five sets of six items each. to evaluate if the effects of training exceeded Training items were obtained from a parallel the potential effectiveness of a condition in form of the Posttest items. The total number of which subjects had to generate solution 30 items was randomly divided into five sets, strategies themselves. No Training was also in- thereby resulting in comparable ranges of difcluded in order to evaluate the relative ficulty between sets. superiority of the Instructional Training ConDuring training, the experimenter modelled ditions and the self-generating Unspecific the first six training items, and followed a stanTraining condition over the absence of any dard set of verbalizations. These verbalizations prior training or familiarity with the task. had been previously developed to provide an Instructional Training. — The procedure exhaustive set of strategies helpful to problem adopted had been devised by Meichenbaum solution and were intended to draw the sub(1974; Meichenbaum & Goodman, 1971) in jects' attention to all possible rules according to order to increase the effectiveness of covert which the letter sets could be constructed. speech as a regulatory function. In general, this These rules were presented in terms of three procedure consisted in the modeling and overt- superordinate rule classes: alphabetical order to-covert fading of self-instructional statements and variations thereof (forward, backward, as a means of developing self-control. First, the alternate), duplications and triplications, and experimenter performed a task while talking vowels vs. consonants, in that order of ocaloud to herself as the subject observed; thus currence (frequency). The experimenter prothe experimenter served as a model. Next, the ceeded to check each item against these rules, subject performed a task while the ex- following their order of occurrence, and verperimenter verbally monitored her behavior. balizing the specific way in which the item was, Subsequently, the subject performed the task or was not, an instance of each rule. while talking aloud to herself, then while Subsequently, subjects were instructed to whispering, and finally, covertly and without work on the next six items in exactly the same visible lip movements nor prompts by the ex- way the experimenter had done. During this perimenter. phase, the experimenter also verbally Verbalization was broad in content and monitored the behavior of the subjects, reminddirected at strengthening (a) self-instructions in ing them of the rules and their ordering if the form of planning and cognitive self- necessary. Finally, subjects solved the remainguidance for the Cognitive Training group, and ing three subsets, the first while talking aloud, (b) the self-instructions just described for the the next while whispering, and the last covertly. Cognitive Training group coupled with inUnspecific Training. — In this condition substructions relevant to Anxiety Training pro- jects worked on the items with no specific incedures, i.e., ways of overcoming anxiety and structions. Standard explanations of the task format were given only, and subjects were told Table 1. Examples of to try to solve all training items. Self-Instructional Statements. No Training. — This group did not receive any training on the Letter Sets Test at all. HowContent Example ever, in order to give subjects in this group Self-guidance What do I have to do? equal familiarity with the experimenter and What is the rule in this set? thus to control for "attention" effects, subjects What idea can I try? What do I do next? were administered an irrelevant task: they were This one does not fit, therefore . . . asked to work on a verbal fluency test. Anxiety coping Think before I give up.
LABOUVIE- VIEFAND GONDA
330
Table 2. Mean Number of Correctly Solved Items and Standard Deviations at Immediate and Delayed Posttests For Training and Transfer Tasks by Training Condition. Training Condition Time of Testing Cognitive Training Mean
SD
Anxiety Training Mean
No Training
Unspecific Training
SD
Mean
SD
Mean
SD
8.47
5.49
8.73
5.73
6.73
3.01
4.67
3.06
Delayed posttest
7.87
6.14
Combined
8.17
5.73
9.33 9.03
5.91 5.73
9.40 8.07
3.72 3.59
6.33 5.50
4.61 3.94
Transfer Task (Raven) Immediate posttest Delayed posttest Combined
26.40
9.64
22.87
7.95
28.07
9.11
23.00
7.09
28.13 27.27
13.11
24.87
8.58
29.80
9.71
23.27
6.73
11.34
23.87
8.19
28.93
9.30
23.13
6.80
administration of the Training Task (Letter Sets Test) and the Transfer Task (Raven's Standard Progressive Matrices) according to standard timed conditions.
Table 3. Dunn Contrasts on Transfer and Training Tasks for Immediate and Delayed Posttests. Posttest Comparison
Immediate
RESULTS
Analysis of the data was aimed at examining both long- and short-term effects of training, as well as the extent to which training is specific versus transferable. The number of correctly solved items was computed for each subject separately for the two times of testing (Immediate and Delayed Post-test) for both the Training (Letter Sets Test) and Transfer Tasks (Raven). These scores constituted the dependent variables for further analysis. The means and standard deviations of the raw scores are presented in Table 2. It is a perennial problem in research on aging (see for example, Birr en, 1970), that intersubject variability tends to be so great that it is often difficult to demonstrate treatment effects. Thus, in order to increase the power of the analysis, pair-wise directional planned contrasts were formed by Dunn's method (Kirk, 1968) between the No Training group on the one hand, and the three remaining groups on the other. These contrasts were formed separately for the Immediate and Delayed Posttest, and for the Training and Transfer Tasks. The results of the Dunn contrasts are presented in Table 3. Note, when examining both Table 3 and Table 2, that a variety of training effects are indeed obtained. With regard to the
Delayed
Training Task (Letter Sets Test) No training vs. cognitive training
3.80* •
1.53
No training vs. anxiety training
4.07* •
3.00"
2.07
3.07"
3.40
4.86*
.13
1.69
No training vs. unspecific training Transfer Task (Raven) No training vs. cognitive training No training vs. anxiety training No training vs. unspecific training
5.07» •
6.53"
Note: Entries are differences in terms of items solved correctly, between stated conditions. Critical values are for the Training Task: d = 2.20 (p < .05) and d = 2.72 {p < .01); for the Transfer Task: d = 3.95 (p < .05) and d = 4.90 (p < .01). •p
Cognitive Strategy Training and Intellectual Performance in the Elderly1
Reduced intellectual performance in the elderly was conceptualized as an experiential deficit that can be reversed by training relevant component skills. Sixty female elderly subjects (ages 63 to 95) participated in three phases of the experiment: Training, Immediate Posttest, and Delayed Posttest. Training was geared at strengthening covert self-monitoring strategies in complex reasoning problems, and training effects were evaluated both on the training and a transfer task. Results showed raised performance in the training conditions, transfer effects, and maintenance of training and transfer effects over 2 weeks. Implications for theories of adult intelligence are discussed.
in the area of adult intellectual RESEARCH redevelopment and aging has indicated, in
general, age-associated performance deficits when young and elderly samples are compared (Baltes & Labouvie, 1973; Riegel, 1973). Usually these differences are interpreted in terms of a maturational model emphasizing biological decrement. However, recent criticisms have called for a reinterpretation of conventional, maturational, decrement-oriented views of aging for the following reasons: (a) causal relationships have been implied from primarily psychometric-descriptive and correlational evidence (Baltes & Labouvie, 1973); (b) the poor covariance between biological status and intelligence in healthy elderly suggests that biological status, at least in the healthy elderly, is a necessary but not sufficient condition for adequate intellectual performance (Hertzog, Gribbin, & Schaie, 1975; Riegel & Riegel, 1972; Wang, 1973); and (c) the strong impact of sociocultural variables as indicated by cohortrelated and other experiential factors, such as life complexity (Schaie & Gribbin, 1975), suggests that, at least in healthy elderly, a major share in cognitive performance is accounted for by experiential parameters (Schaie, 1975; Schaie & Labouvie-Vief, 1974). Thus, some authors have argued for a stronger emphasis on environmental and experiential factors (Baltes & Labouvie, 1973; Labouvie-Vief, 'The current research was supported by a grant from the National Institutes of Health (1-R01, MD-07867-01). The authors wish to thank Mary Gander and Margaret Semrud for their help in carrying out the project. •Univ. of Wisconsin, Dept. of Educational Psychology, Madison 53706.
Hoyer, Baltes, & Baltes, 1974). This view calls for a de-emphasis on conceptualizations of poor performance as a competence deficit and an emphasis on exploration of parameters linked to performance deficits. The present study conceptualized reduced intellectual performance as an experiential deficit that can be reversed by concentrating on the training of certain component skills. According to Baltes and Labouvie (1973), these component behaviors may either be directly intellectual, or they may be nonintellectual but nevertheless performance-related. The first of these classes relates to skills and strategies that are cognitive in nature and have in general been discussed in terms of the elderly individual's failure to use effective verbal mediators and planning strategies in solving tasks (Botwinick, 1967; Goulet, 1973; Kausler, 1970). The second group is more general and comprises such skills as ways of coping with test-anxiety, frustration, and failure; this class of skills thus far has not been investigated in relation to intellectual performance, although its major importance has been noted in learning tasks (Eisdorfer, Nowlin, & Wilkie, 1970). Actual research manipulating both classes of factors has been rare thus far, but has produced promising results (Crovitz, 1966; Hoyer, Labouvie, & Baltes, 1973; Meichenbaum, 1974). The present study, therefore, examined the effect of strategy training on intellectual performance in the elderly. In addition, this research attempts to deal with two criticisms often raised in relation to intervention-oriented 327
Downloaded from http://geronj.oxfordjournals.org/ at University of Iowa Libraries/Serials Acquisitions on July 23, 2015
Gisela Labouvie-Vief, PhD,2 and Judith N. Gonda, MA
328
LABOUVIE- VIEFAND GONDA
METHOD
Subjects A sample of 60 females was recruited from a Madison, Wisconsin, public housing development for elderly people. Subjects were randomly selected from the total population of the housing development and asked to volunteer for the research. Each participant received a remuneration of $9.00 on completion of the second post-test. Subjects ranged in age from 63 to 95 with a mean age of 76 years. The subjects were randomly assigned to one of four training groups of 15 each. Procedure The study consisted of three phases: Training, Immediate Posttest, and Delayed Posttest. Four training groups were involved at each phase: two instructional groups, Cognitive Training and Anxiety Training, and two control groups, Unspecific Training and No Training. The training was given on a set of inductive reasoning problems — items taken from a parallel form of the Immediate Posttest, the Letter Sets Test (French, Ekstrom, & Price, 1963). Immediately following the training procedure, the effect of the different modes of training on the Training Task were assessed during Immediate Posttest. At the same time, in order to determine any potential generalized effects of the training procedure, a Transfer Test, the Raven's Progressive Matrices (Raven, 1958), consisting of a different type of inductive reasoning problems was administered. Delayed Posttest consisted in the administration of the Training and Transfer Test approximately 2 weeks after Immediate Post-
test. The interval between the two sessions averaged 14 days (range: 10-28). Subjects were tested in their homes by two female graduate students. Training Task According to current theorizing in the area of intellectual abilities, different intellectual abilities differ markedly in the extent to which they are trainable (Horn, 1970), depending upon the degree to which they represent the effects either of acculturation or of the biological-maturational well-being of the individual. Since the purpose of the present study was to explore the utility of an environmental rather than biological deficit interpretation of aging decrements, the strongest test was considered to be offered by a task that traditionally had been interpreted to indicate the degree ef biological decrement in the elderly. In CattellY (1963) and Horn's (1970) framework of fluid and crystallized intelligence, this would be true of fluid intelligence, which is marked best by tests of inductive reasoning (Horn, 1970). A test of inductive reasoning, the Letter Sets Test, was therefore chosen as the training task. This test was obtained from the French et al. (1963) Kit of Reference Tests for Cognitive Factors, a careful compilation of reference tests that is based on extensive factor-analytic structuring of the ability domain. The Letter Sets Test presents the subjects with five sets of four letters in each item. The task is to find which rule relates the four letters within each to each other, and to mark the one which does not fit the rule. Transfer Task A task related to the Training Task was included to provide for a more powerful estimate of the generalizability of the training procedure. The Transfer Test, Raven's Standard Progressive Matrices, is, like the Letter Sets Test, a marker of inductive reasoning. Training Procedure In general, the training procedure was aimed at the modification of subjects' verbal selfmonitoring during task performance. It was hypothesized that elderly subjects spontaneously generate a high frequency of task-interfering self-instructional statements, thus resulting in ineffective self-regulation of behavior. This hypothesis was tested by the comparison between four training groups. The first two of these (In-
Downloaded from http://geronj.oxfordjournals.org/ at University of Iowa Libraries/Serials Acquisitions on July 23, 2015
research. The first of these relates to the problem that training, although facilitative, may be highly task-specific and thus may not really represent a broad class of strategies that will raise intellectual behavior, in general (Kohlberg, 1968). To counter this objection the present study examined the effects of training not only on the training task itself, but on other tasks (transfer tasks) as well. The second problem similarly concerns the generalizability of training effects, but relates to their transitory rather than narrow nature. Consequently, the proposed research also included an examination of the long-term facilitative effects of the training.
TRAINING AND INTELLIGENCE IN THE ELDERL Y
329
Go slowly, keep trying. Don't get stuck, try another. Now I know how it works. Good, that's correct. I'm half the way through, already.
Posttests Both the Immediate and Delayed Posttests followed the same procedure, consisting in the
Downloaded from http://geronj.oxfordjournals.org/ at University of Iowa Libraries/Serials Acquisitions on July 23, 2015
structional Training groups) constituted the of coping with failure, and self-approval rather training groups proper (Cognitive Training, than criticism. Examples of both classes of Anxiety Training). Unspecific Training served statements are given in Table 1. to compare the effectiveness of the InTraining was done in individual sessions. For structional Training with effects of test each session, a special training booklet was profamiliarity, per se. Thus this condition served vided consisting of five sets of six items each. to evaluate if the effects of training exceeded Training items were obtained from a parallel the potential effectiveness of a condition in form of the Posttest items. The total number of which subjects had to generate solution 30 items was randomly divided into five sets, strategies themselves. No Training was also in- thereby resulting in comparable ranges of difcluded in order to evaluate the relative ficulty between sets. superiority of the Instructional Training ConDuring training, the experimenter modelled ditions and the self-generating Unspecific the first six training items, and followed a stanTraining condition over the absence of any dard set of verbalizations. These verbalizations prior training or familiarity with the task. had been previously developed to provide an Instructional Training. — The procedure exhaustive set of strategies helpful to problem adopted had been devised by Meichenbaum solution and were intended to draw the sub(1974; Meichenbaum & Goodman, 1971) in jects' attention to all possible rules according to order to increase the effectiveness of covert which the letter sets could be constructed. speech as a regulatory function. In general, this These rules were presented in terms of three procedure consisted in the modeling and overt- superordinate rule classes: alphabetical order to-covert fading of self-instructional statements and variations thereof (forward, backward, as a means of developing self-control. First, the alternate), duplications and triplications, and experimenter performed a task while talking vowels vs. consonants, in that order of ocaloud to herself as the subject observed; thus currence (frequency). The experimenter prothe experimenter served as a model. Next, the ceeded to check each item against these rules, subject performed a task while the ex- following their order of occurrence, and verperimenter verbally monitored her behavior. balizing the specific way in which the item was, Subsequently, the subject performed the task or was not, an instance of each rule. while talking aloud to herself, then while Subsequently, subjects were instructed to whispering, and finally, covertly and without work on the next six items in exactly the same visible lip movements nor prompts by the ex- way the experimenter had done. During this perimenter. phase, the experimenter also verbally Verbalization was broad in content and monitored the behavior of the subjects, reminddirected at strengthening (a) self-instructions in ing them of the rules and their ordering if the form of planning and cognitive self- necessary. Finally, subjects solved the remainguidance for the Cognitive Training group, and ing three subsets, the first while talking aloud, (b) the self-instructions just described for the the next while whispering, and the last covertly. Cognitive Training group coupled with inUnspecific Training. — In this condition substructions relevant to Anxiety Training pro- jects worked on the items with no specific incedures, i.e., ways of overcoming anxiety and structions. Standard explanations of the task format were given only, and subjects were told Table 1. Examples of to try to solve all training items. Self-Instructional Statements. No Training. — This group did not receive any training on the Letter Sets Test at all. HowContent Example ever, in order to give subjects in this group Self-guidance What do I have to do? equal familiarity with the experimenter and What is the rule in this set? thus to control for "attention" effects, subjects What idea can I try? What do I do next? were administered an irrelevant task: they were This one does not fit, therefore . . . asked to work on a verbal fluency test. Anxiety coping Think before I give up.
LABOUVIE- VIEFAND GONDA
330
Table 2. Mean Number of Correctly Solved Items and Standard Deviations at Immediate and Delayed Posttests For Training and Transfer Tasks by Training Condition. Training Condition Time of Testing Cognitive Training Mean
SD
Anxiety Training Mean
No Training
Unspecific Training
SD
Mean
SD
Mean
SD
8.47
5.49
8.73
5.73
6.73
3.01
4.67
3.06
Delayed posttest
7.87
6.14
Combined
8.17
5.73
9.33 9.03
5.91 5.73
9.40 8.07
3.72 3.59
6.33 5.50
4.61 3.94
Transfer Task (Raven) Immediate posttest Delayed posttest Combined
26.40
9.64
22.87
7.95
28.07
9.11
23.00
7.09
28.13 27.27
13.11
24.87
8.58
29.80
9.71
23.27
6.73
11.34
23.87
8.19
28.93
9.30
23.13
6.80
administration of the Training Task (Letter Sets Test) and the Transfer Task (Raven's Standard Progressive Matrices) according to standard timed conditions.
Table 3. Dunn Contrasts on Transfer and Training Tasks for Immediate and Delayed Posttests. Posttest Comparison
Immediate
RESULTS
Analysis of the data was aimed at examining both long- and short-term effects of training, as well as the extent to which training is specific versus transferable. The number of correctly solved items was computed for each subject separately for the two times of testing (Immediate and Delayed Post-test) for both the Training (Letter Sets Test) and Transfer Tasks (Raven). These scores constituted the dependent variables for further analysis. The means and standard deviations of the raw scores are presented in Table 2. It is a perennial problem in research on aging (see for example, Birr en, 1970), that intersubject variability tends to be so great that it is often difficult to demonstrate treatment effects. Thus, in order to increase the power of the analysis, pair-wise directional planned contrasts were formed by Dunn's method (Kirk, 1968) between the No Training group on the one hand, and the three remaining groups on the other. These contrasts were formed separately for the Immediate and Delayed Posttest, and for the Training and Transfer Tasks. The results of the Dunn contrasts are presented in Table 3. Note, when examining both Table 3 and Table 2, that a variety of training effects are indeed obtained. With regard to the
Delayed
Training Task (Letter Sets Test) No training vs. cognitive training
3.80* •
1.53
No training vs. anxiety training
4.07* •
3.00"
2.07
3.07"
3.40
4.86*
.13
1.69
No training vs. unspecific training Transfer Task (Raven) No training vs. cognitive training No training vs. anxiety training No training vs. unspecific training
5.07» •
6.53"
Note: Entries are differences in terms of items solved correctly, between stated conditions. Critical values are for the Training Task: d = 2.20 (p < .05) and d = 2.72 {p < .01); for the Transfer Task: d = 3.95 (p < .05) and d = 4.90 (p < .01). •p
