The Ruff Figural Fluency Test: A Normative Study

DEVELOPMENTAL NEUROPSYCHOLOGY. 1987.3(1).37-51
Copyright " 1987. Lawrence Erlbaurn Associates. Inc.
The Ruff Figural Fluency Test:
A Normative Study With Adults
Ronald M. Ruff and Rudolph H. Light
University of California at San Diego
Randall W. Evans
University ofNorth Carolina at Chapel Hill
Tests of verbal production, or fluency, have proved to be reliable and sensitive
indices of brain dysfunction in a variety of clinical populations. Also, numer ous studies suggest that disturbed verbal fluency can be linked to specific brain
lesions. Less is known, however, about figural fluency performance in normal
or in clinical groups. Although Jones-Gotman and Milner (1977) tested an experimental figural, or design, fluency test in a circumscribed group of brainimpaired patients, their test lacked psychometric sophistication. Presented
herein is a new figural fluency test in a sample of 358 normal adults . The test
proved to be reliable, and the data support that the performance depended not
on sex, but on age and education. Moreover, figural fluency did not correlate
with measures of motor speed or verbal fluency; modest correlations, however.
were present with Performance IQ. Finally, the potential for neuropsychological applications of this new test are discussed.
Fluency tests assessing both cognitive flexibility and response speed have
proved themselves as yielding measures in clinical neuropsychology because
they reliably discriminate patients with cerebral damage from normals. More
in particular, damage to the frontal lobes of the brain results in a reduction of
fluency (Benton, 1968; Milner, 1964; Perret, 1974; Ramier & Hecaen, 1970);
also, patient populations with more diffuse brain damage can exhibit these
reductions (Rosen, 1980). In these early studies, the investigative focus was
on testing verbal associative fluency, which requires the participant to produce words beginning with a given letter of the alphabet over a given time
period.
Requests for reprints should be sent to Ronald M. Ruff , Division of Neurological Surgery
(H-893), University of Californ ia, 225 Dickinson Street, San Diego, CA 92103.
38
RUFF, LIGHT, EVANS
Recently, attempts have been made to develop an analogous fluency task
for testing the visuospatial mode of fluency. In one such effort, JonesGotman and Milner (1977) first asked their participants to draw different designs during a 5-min period and, in a second step, to limit the designs or patterns to four parts (straight or curved lines, circles, etc.) during a period of 4
min. This is analogous to the verbal fluency task introduced by Thurstone
and Thurstone (1949) in which a participant is asked to write as many words
starting with the letter "s" as possible, and, in a second step, to write fourletter words beginning with "b." Jones-Gotrnan and Milner's results supported the hypothesis of a double dissociation between left anterior lesions of
the brain selectively producing a reduction of verbal fluency while sparing
nonverbal fluency, with the converse being demonstrated secondary to right
frontal lobe lesions. This finding is potentially especially powerful, because
right frontal lobe dysfunctioning is particularly elusive to psychometric
evaluation.
In attempting to clinically utilize the technique introduced by JonesGotman and Milner, major difficulties were encountered in scoring
a patient's drawings. All too frequently the consensus reached between
examiners as to whether two drawings were essentially the same or were different enough to rule out a repetition was problematic. For example, it is virtually impossible to draw or, alternatively, to determine if two designs are
identical; therefore, an examiner constantly needs to rely on subjective
judgment. Also, some patients would make elaborate drawings (e.g ., of a bicycle, of faces or animals) that take more time, and the complexity of such
designs would affect the total score. These subjective scoring procedures fall
short of the tests developed for verbal fluency (Benton, 1968; Thurstone &
Thurstone, 1949), which have objective and reliable procedures for measuring the total number of productions or perseverations.
While collaborating at the University of Zurich, Serrat, Ruff, and Regard
developed a nonverbal fluency measure, the elements of which were soundly
based in psychometric technique. Patients were asked to generate different
designs in the context of a given framework . Specifically, this measure
consisted of a sheet of paper partitioned into rectangles. Each rectangle contained five dots arr-anged in a configuration like that in which the number five
appears on a die. Participants were asked to connect two or more of the five
dots with straight lines, with the goal being to draw as many different designs
as possible within a period of 5 min. This method was first reported by Regard, Strauss, and Knapp (1982) with data collected on a sample of normal
children in Grades 1,3, and 7. Their results documented a steady and significant improvement in figural fluency associated with increase in age but not
with sex.
Ruff and his colleagues introduced a modified version that was initially
presented to gifted children in Grades 2, 4, and 6. Their results suggested an
FIGURAL FLUENCY: NORMS FOR ADULTS
39
age-related improvement on figural as well as verbal fluency measures
(Evans, Ruff, & Gualtieri, 1985). To explore the neuropsychological utility,
the same figural fluency task was administered to a sample of traumatically
head injured adults (Ruff, Evans, & Marshall, in press). These patients not
only achieved significantly inferior performances when compared to normal
controls, but a significant discrimination was also obtained between victims
whose brain trauma had been classified as moderate or severe. Note that
these classifications of severity were independently made by a team of
neurosurgeons at the time of resuscitation. Thus, the figural fluency task was
demonstrated to be sensitive to severity of brain trauma. Together with our
clinical experience gained through administering this newly developed fluency task to every clinical referral made over the past 3 years to the Neuropsychology Unit at the University of California Medical Center, this data
gave us the impetus for norming this figural fluency measure on a sample of
adults.
In contrast to the Regard et al. (1982) measure utilizing systematically
arranged five-dot patterns, the Ruff et al. measure utilized randomly
arranged configurations of dots, with some dot matrices being juxtaposed
with interference designs. The purpose of this arrangement was to avoid ceiling effects by increasing the spatial complexity involved in the task while
requiring figure-ground separation. Moreover, five different dot configurations were introduced for the purpose of assessing cognitive flexibility.
Conceptually, this takes into account that in the neuropsychological sense,
"fluency," or the ability to perform fluently, encompasses several aspects of
behavior. Jones-Gotman and Milner (1977) emphasized that "spontaneity"
(a.k.a. initiation) of productions is essential for fluent performance; therefore, in the present measure it was left up to the testee to decide whether to
draw simple or more complex designs. Others have emphasized that fluent
performance should be void of "perseverative tendencies" (Perret, 1974);the
present measure captures the potential for perseveration in each of the five
different parts. Still others have suggested that fluency can be influenced by
deficits in "self-awareness" or by "concrete attitudes"; this contributed to the
decision to add interference designs in two of the five parts .
The purpose of the present study was to assess the effects of aging and
achieved levelof education on adult performance ofthe Ruff Figural Fluency
Test (RFFT). Basically, our hypothesis was that younger adults would generate more designs when compared to older adults. An additional question
raised was whether this age-dependent performance would be related to a
slowing in motor speed per se. We also postulated a higher rate of figural fluency corresponding to a higher level of education. The hypothesis relating a
higher rate of figural fluency to a higher level of education also raised the
question as to whether test intelligence would be related to figural fluency. In
addit ion, the question of retest reliability was addressed because we are
40
RUFF, LIGHT, EVANS
continuing our studies to assess the effect of both focal and diffuse cerebral
damage on figural fluency; the present study also served the purpose of providing normative data.
METHOD
Participants
The sample included 358 normal volunteers (197 women, 161 men) ranging
in age from 16to 70 years and ranging in education from 7 to 22 years. About
65OJo of the participants resided in California, 30% resided in Michigan, and
the rest resided on the eastern seaboard. Care was taken to ensure that the
population was heterogeneous with respect to age and education; there were
four age groups and three education groups, so the sampling procedure resulted in 12 independent subgroups, each containing about 25 to 30 people
(see Table 1). All participants were screened to exclude those with a positive
history of psychiatric hospitalization, chronic polydrug abuse, or neurological disorder.
Procedure
The RFFT consists of five parts, each containing a different stimuli presentation (see Figure 1). Each part is composed of a 5 x 7 array of identical stimulus items printed in black on white 8V2- x ll-in. sheets of paper. For each
part of the test, three samples of the particular stimulus items are given.
These are shown to the participant at the same time the instructions are given.
Starting with Part 1, the instructions are:
In front of you are three squares, each containing five dots. Note that
the arrangement of the five dots is always the same. I want you to connect two or more dotsby always using straight lines. The purpose of the
TABLE 1
Sample of Participants Arranged by Age and Education
Education
12 Years or Less
Age
Male
Female
13 to 15 Years
Male
Female
16 Years or More
Male
Female
16to 24years
14
16
15
14
5
16
25 to 39 years
40 to 54 years
55 to 70 years
15
12
9
16
16
18
16
17
15
20
15
16
16
15
12
18
17
15
FIGURAL FLUENCY: NORMS FOR ADULTS
•
• • 00. o . 0
•
• • s O· 0
I
II
FIGURE 1
ill
•
• •
•
•
41
•
• • •
:rsz:
V
RFFT Parts 1 through 5.
test is for you to make as many designs or patterns as possible, but each
design has to be different in some way from all the others.
The participant is then asked to complete the samples and, if necessary, is reminded that, for example, not all five dots need to be connected within each
square. A red felt-tip pen is used to provide highlighting and clarity. Drawing
different designs and speed in producing designs are again emphasized, and
the participant is then given 1 min to complete each part. Note that the procedure of first giving sample drawings to the participant is repeated for every
part of the test.
The first page the participant sees has dots arranged in frames of regular
pentagons, 35 frames in all. Succeeding pages include distractors (e.g., heavy
black lines that only trace a pattern within each frame but also from one
frame to another or that may have added small diamonds in each frame). The
last two pages of the test present patterns of dots arranged in an irregular
shape.
The primary dependent measures of figural fluency were the number of
unique designs generated and the number of perseverations made. Perseverations refer to any produced designs that were repeated on one or more occasions within one of the test parts. Therefore, in order to determine the number of unique designs a participant produced, it was necessary to determine
the number of squares in which the participant connected two or more dots in
a different manner. This reduced any need for the examiner to rely on judgment. There are literally hundreds of possible ways to connect the dot matrices in unique designs. A combination of two scores comprise the "error ratio," which is defined as the total number of perseverations divided by the
total number of unique designs. Approximately 28oro of the total sample (N
= 95) was retested after 6 months in order to determine test reliability.
RESULTS
Sex Differences
Table 2 shows both the total number of unique designs and perseverations
subdivided according to sex as well as to age and education. Within each of
42
RUFF , LIGHT, EVANS
TABLE 2
Unique Designs and Perseverations Arranged by Sex, Age, and Education
Education
12 Years or Less
Age
16 to 24 years
25 to 39 years
40 to 54 years
55 to 70 years
N
Designs
Perseverations
N
Designs
Perseverations
N
Designs
Perseverations
N
Designs
Perservations
Male
Female
14
105
4.9
15
81
5.6
12
88
6.3
9
75
11.1
16
102
4.3
16
83
8.1
16
83
15.0
18
66
10.7
p
.75
.79
.77
.36
.58
.05
.29
.95
16 Years or More
131015 Years
Male
15
105
10.4
16
97
8.8
17
94
10.1
15
75
15.5
Female
p
14
110
6.1
20
102
7.3
15
94
8.1
16
77
8.4
.49
.38
.57
.56
.91
.56
.70
.16
Male
Female
5
116
5.0
16
94
12.9
15
102
11.1
12
91
6.8
16
112
8.9
18
109
7.4
17
108
12.0
15
79
11.4
p
.71
.27
. 12
.38
.35
.90
.13
.06
the 12 subgroups, the design performances of women and men demonstrated
no significant differences. With respect to perseverative errors, the distributions were skewed. In two of the subgroups, women, when compared to men,
made more errors, and the p value approached significance (in the subgroup
with 12years of education or less and ages ranging from 40 to 55 years, the error score for women was 15.0, and the error score for men was 6.25, p =
.051; in the subgroup with 16 years of education or less and ages ranging
from 55 to 70 years, the error score for women was 11.4, and the error score
for men was 6.8, p = .06); all other p values were nonsignificant and ranged
from .16 to .95. Based on the lack of major differences between women and
men, their performances were combined in all the following analyses.
Age and Education
The RFFT scores consist of the total number of unique designs made; in
each of the 12 subgroups, the distribution of scores closely approximates a
normal curve. Although the trend is not perfectly linear, scores vary inversely
with an increase in age (see Figure 2). In general, younger participants do
best; those participants between ages 25 and 55 score essentially the same and
somewhat lower; the older sample achieved the lowest scores.
When the effect of education is analyzed, scores are significantly better for
college graduates when compared to samples of high school educated participants. A two-way analysis of variance (ANOVA) for total designs, calculated
with the data presented in Table 3, demonstrated significance for the factor
FIGURAL FLUENCY : NORMS FOR ADULTS
43
EDUCATION
o
~
P. 120
(fl,
•
z ...
(!)~
(j) 6
$12yrs
13-15yrs
~ 16yrs
Wa..
a .. 90
we;
::::> ......
Q~
Z
::::>
FIGURE 2 Total unique designs
subdivided according to age and
education.
E
::I
(fl
60
16-24 25-39 40-54 54-70
AGE GROUP
TABLE 3
Total Unique Design Scores and Standard Deviations for
All Subgroups Arranged by Age and Education
Education
12 Years or Less
Age
16 to
25 to
40 to
55 to
24 years
39 years
54 years
70 years
13 to 15 Years
16 Years or More
M
SD
M
SD
M
SD
103.3
82.1
86.0
67.5
23.8
18.7
22.4
19.9
108.2
99.9
93.9
77.2
18.6
23.6
17.8
17.7
113.1
104.1
106.3
84.4
21.2
25.4
16.2
20.8
of Age, F(3, 346) = 32.2, p < .001, w2 = .19, and for the factor of Education, F(2, 346) = 18.4, p < .001, w2 = .07, whereas the interaction values
were nonsignificant, F(6, 346) = .84,p > .05. Given these clear and substantial differences for the factors of Age and Education, it seems essential that
theseparation of the participant sample intosubgroups bemaintained.
Error Scores
For the total number of perseverations, no particular pattern was evident
among the subgroups (see Table 4). These scores, however, are much more
variable than the design scores. The average number of perseverations for all
358 participants was 9.2, with a standard deviation of 12.2 perseverations.
The distribution was highly skewed because a small number of participants in
each age and education subgroup had a large number of perseverations. In
the most extreme cases, this amounted to over 90 perseverations in five pages.
44
RUFF, LIGHT, EVANS
TABLE 4
Perseveration Scores and Standard Deviations for All Subgroups Arranged by Age and
Education and With Outliers Included and Suppressed
Education
12 Years or Less
N= 338
(Outliers
N = 358 Removed) N
Age
16 to 24 years M
SD
Maximum
25 to 39 years M
SD
Maximum
40 to 54 years M
SD
Maximum
55 to 70 years M
SD
Maximum
value
value
4.6
6.2
27
6.9
7.5
25
11.3
n .s
value
value
52
10.9
13.8
57
4.6
6.2
27
6.9
7.5
25
7.9
6.2
24
7.4
6.2
22
13 to 15 Years
16 Years or More
N= 338
N = 338
(Outliers
(Outliers
= 358 Removed) N = 358 Removed)
8.4
12.8
63
8.0
7.7
38
9.2
9.4
41
ll .8
13.9
71
5.3
4.4
16
7.1
5.8
24
7.3
6.1
28
9.0
7.6
29
8.0
6.7
32
10.0
18.0
100
11.6
20.2
91
9.3
6.4
22
6.8
3.9
14
5.7
5.9
23
5.1
4.5
19
9.3
6.4
22
One is tempted to view these as true outliers in their rarity, and as such they
bear further discussion.
Using the technique of Anscombe and Tukey (1963), these highly discrepant values were removed, and new descriptive statistics were calculated. The
criterion for removal was that the total number of participant perseverations
had to be greater than 2 SD from the mean (upper 2.50/0) over the total number of 358 participants. The procedure resulted in the loss of 20 participants
of the initial 358, and the new distribution became much less positively
skewed. The new grand mean for perseverations became 6.8, and the
standard deviation decreased from 12.2 to 6.1 perseverations. (The cutoff of
the actual total number of perseverations was 30.) The use of this technique
demonstrated a much smaller deviation for all groups, with the distributions
being more normal and more homogeneous. A two-way ANOVA was performed regarding transformed data. It showed that the effect of age was significant, F(3, 326) = 3.70, P < .05, w2 = .02; however, both the factor of
Education, F(2, 326) = .29, p > .05, and the interaction value were not statistically significant, F(6, 326) = 1.07, p > .05. The effect of age is significant because older people make significantly more perseveration errors than
young people. Nevertheless, the measure of association used, omega
squared, is so small as to show the association to be meaningless. For all prac-
FIGURAL FLUENCY : NORMS FOR ADULTS
45
tical purposes, there is no difference among normal participants across all
groups with respect to the numbers of errors made .
Examining these identified discrepant scores in detail leads to some interesting findings . The reasons for such high error scores among these relatively
few people must be diverse. Upon completion of the test, several of these participants were asked if they had indeed attempted to make all their designs
different. A few acknowledged that they had tried for speed rather than performance accuracy, and a few said that they had not understood the instructions properly. Some were unaware that they had made so many duplicate designs. In the administration of the RFFT, therefore, it is essential to stress to
participants that they follow the required procedure of generating as many
different designs as possible without repetitions in order to avoid spuriously
high perseveration scores.
Intelligence level may have a bearing on assessments of figural fluency. In
particular, Wechsler Adult Intelligence Scale-Revised (WAIS-R) Full Scale
IQ (FIQ) scores were inversely related to the total number of perseverations
on the RFFT. Twenty participants had outlying values of 30 perseverations
or more, and their mean FIQ was 104, with a standard deviation of 16.1. This
compares to the 338 participants whose total perseverations were less than 30
and for whom the mean FIQ was Ill, with a standard deviation of 14.1 (a significantly higher FIQ) .
Error Ratio
To analyze the relationship between unique designs and perseverations, an
error ratio was calculated by contributing the following two scores : total
number of perseverations divided by total number of unique designs. Figure
3 demonstrates an overall trend - the older the participant, the greater the ratio . This trend is particularly pronounced across the four age groups with 12
years of education or less.
.20
0
~12yrs
•
:!:16yrs
ss 13-15 yrs
I-
«
a:
a: .10
0
a:
a:
w
FIGURE 3 Error ratio: total
number of perseverations divided
by total number of unique designs.
EDUCATION
o
0
16-24 25-39 40-54 55-70
AGE GROUP
46
RUFF, LIGHT, EVANS
Five Parts
Using the normative test sample with outliers removed, there were no performance differences among the five parts of the test. The number of
perseverations was marginally greater for Parts 4 and 5 when the dots were
arrayed randomly. But, the number of designs produced likewise was fairly
high with Part 5, offsetting the error scores . As shown in Table 5, no consistent tendencies were evident.
Motor speed. Motor speed for the dominant hand, as measured by the
Finger Tapping Test, did not correlate with the total number of unique designs produced by participants. It was possible that the decline noticed
among those participants who were older was in great measure due to motor
slowing with advancing age. However, the correlations obtained (see Table 6)
suggest that at all ages and education levels, no relationship exists between
performance on the RFFT and motor speed.
Test intelligence. Because the RFFT is a nonverbal measure of fluency, one might expect results to correlate to some degree with Performance
TABLE 5
Comparisons Among the Five Parts of the RFFT in
Mean Numbers of Designs and Perseverations
Designs
Part
2
3
4
5
Perseverations
M
SD
M
SD
17.3
18.9
19.1
18.8
19.6
5.7
5.4
5.8
4.8
5.1
1.0
1.4
1.4
1.8
2.2
2.0
1.1
1.4
1.8
1.7
Note. N = 338, outliers removed .
TABLE 6
Correlations Between RFFT Designs and Finger Tapping Test of
Motor Speed for Dominant Hand
Education
Age
12 Years or Less
13 to 15 Years
16 Years or More
- . Il
16 to 24 years
- .18
- .06
25 to 39 years
.02
.17
.23
40 to 54 years
55 to 70 years
.31
.29
.04
.22
- .06
. 15
FIGURAL FLUENCY: NORMS FOR ADULTS
47
IQ (PIQ) of the WAIS-R. Table 7 shows that correlations are only moderate,
but in over half the cells, they are significant.
Verbal fluency. The Controlled Oral Word Association Test was used
as a verbal fluency measure with which to compare the RFFT. Although the
correlations are in nearly all cases positive (Table 8), there was a consistent
lack of significance.
Reliability. Reliability was assessed using the test-retest method. One
hundred people were chosen for the reliability study and were distributed
more or less evenly in all age and education groups. By chance, 5 were among
those with total perseveration scores of 30 or greater, which led to their being
eliminated from the data set, leaving 95 participants. Even after the 6-month
period of time from testing to retesting, people did significantly better on the
average on the retest (Table 9).
On the first test, this subsample produced an average of 100.6 unique designs, with a standard deviation of 21.8 unique designs; upon retest, it produced an average of 108.6 unique designs, with a standard deviation of 22.1
unique designs . The correlation coefficient was. 76. Perseveration scores did
not differ much from the first test to the retest, but they were much less reliaTABLE 7
Correlations Between RFFT Designs and WAIS-R PIQ
Education
Age
16 to
25 to
40 to
55 to
24 years
39 years
54 years
70 years
12 Years or Less
13 to 15 Years
.53"
.33·
.69......
.02
.48··
.34·
.38"
.50· ·
16 Years or More
.25
.44· ·
.27
.28
"p < .05. • "p < .01. •••p < .001.
TABLE 8
Correlations Between RFFT Designs and Controlled Oral Word
Association Test Scores
Education
Age
12 Years or Less
13 to 15 Years
16 Years or More
16 to 24 years
.25
.17
.35
25 to 39 years
.26
.18
.23
40 to 55 years
55 to 70 years
.18
.08
.32
.09
.17
- .08
48
RUFF , LIGHT, EVANS
TABLE 9
Test-Retest Reliability for Numbers of Unique Designs on Each Part of the RFFT
Part
1
2
3
4
5
Total
First test mean
19.1
20.3
20.3
20.2
20.6
100.6
Second test mean
22.1
.58
21.5
.59
22.0
21.1
21.9
108.6
r
.67
.60
.69
.76
ble. On the first test, the average was 6.53 perseverations, with a standard deviation of 5.8 perseverations; on the second test, the average was 7.76
perseverations, with a standard deviation of 4.8 perseverations. The correlation coefficient was .36. Perseveration scores, as noted earlier, are inherently
more variable than design scores , so the correlation coefficient should indeed
be somewhat lower. Moreover, because the perseveration scores, even with
the removal of outlying values, have skewed distributions, correlations are
bound to be low.
It is noteworthy that although a normal participant was likely to increase
the number of unique designs produced upon retest - indicating a change related to cognitive flexibility and a subsequent increase in response speedthere was no marked change in the number of perseverations. This probably
has clinical implications; for example, a head-injured patient may also increase the number of patterns or designs produced upon retest due to prior
test exposure. If the number of perseverations of the cognitively impaired
participant should be significantly reduced upon retest, it may well indicate
recovery of ability ; this is not the case with the normal participant.
DISCUSSION
The present study was designed to analyze a figural fluency measure in order
to determine the effect of aging. Because other researchers have already analyzed the aging factor in children (Evans et al., 1985; Regard et al. , 1982), we
chose to focus on adults ranging In age from 16 to 70 years. The results clearly
confirmed the hypothesized decline in performance with advancing age.
When contrasted against all the older subgroups, the 16- to 24-year-old subgroup achieved consistently superior performances across all three education
levels. The two middle-aged groups-25- to 39-year-olds and 40- to 54-yearolds - performed at approximately equivalent levels within each of the education groups (Table 3); however, the oldest subgroup-55- to 70-year-
olds -lagged significantly behind all younger participants. These declines
were not significantly correlated with motor slowing, which suggests more
cognitively based aging processes.
FIGURAL FLUENCY: NORMS FOR ADULTS
49
A further aim of the present study was to address those factors that can enhance the neuropsychological application of the RFFT. The introduced psychometric procedure was found to be sound. Each of the five parts of the
RFFT were documented as being reliable, and an equivalency of performance was observed across the five parts (see Tables 5 and 9). Therefore, the
learning effect within 6 months appears to be minimal; the measure also appears stable with respect to intratest scatter.
The factor of Education clearly delineated consistent and systematic differences (see Tables 2 and 3). Our data support the idea that the ability to perform fluency tasks is positively correlated with years of formal schooling.
Heaton, Grant, and Adams (1986) documented the educational influence on
other neuropsychological tests. Similarly, Cauthen (1978) reported on the
positive correlation between IQ and fluency performance. For most tests,
however, normative data stratified according to age and education appear to
be relatively sparse in the neuropsychological literature. Obviously, lack of
this information limits the reliability from which normal versus pathological
decline can be determined. This issue is not trivial, particularly if neuropsychological test performance is used to determine diagnosis, as is the case
in determining accelerated cognitive decline (as found in dementia). It seems
reasonable to assume that the lack of adequate age and education norms can
lead to overidentification of pathology, particularly in the elderly.
Future studies are needed to delineate fully the application of figural fluency in the field of clinical neuropsychology. The present investigators have
special interest in the study of brain trauma victims, and the RFFT has been
successfully applied to discriminate between moderately and severely head
injured patients (Ruff et al., in press) . Additional studies are assessing patients with focal cerebral damage. If these studies are to be effective, however, a reasonably thorough understanding of the RFFT with normals is first
required. For example, Jones-Gotman and Milner's (1977) finding of double
dissociation between verbal and figural fluency relative to left and right frontal lobe lesions needs to be replicated using a more psychometrically sound
fluency test.
In a recent article, Whelihan and Lesher (1985) hypothesized that measures
of frontal lobe functioning tend to decline in disproportion to other cognitive
measures. This is a tantalizing idea, although not a particularly new one . In
any event, the basic idea advanced by Whelihan and Lesher is that "frontal
functions show greater deficits than nonfrontal functions with aging" (p.
378). However, a potential problem with their findings is that the test measures employed as "nonfrontal" are not as sophisticated psychometrically as
the frontal lobe measures; therefore, the comparison is tenuous. That is,
many of the nonfrontal tests are usually scored categorically and do not incorporate elements of speed or varying degrees of impairment. Whelihan and
Lesher note that their findings need clarification and additional research.
50
RUFF, LIGHT, EVANS
It is generally agreed that one's ability to plan and execute purposeful behavior declines with advancing age. In psychometric studies, this decline is
assessed on tests such as the Trail Making Test, the Stroop Word Naming
Test, and the Wisconsin Card Sorting Test. It is not unreasonable to assume
that these tests would be correlated with each other and that performance on
one measure could predict, in a reasonable manner, performance on the
other. This issue is largely unanswered, however , and it is entirely possible
that the correlation may turn out to be relatively modest due to the known
functional divisions within the frontal cortex itself (for a review, see Stuss &
Benson, 1984)and due to disparity of test parameters within these individual
tests (e.g., the Stroop Word Naming Test is timed and emphasizes speed of
response; the Wisconsin Card Sorting Test is untimed and emphasizes concept formation; the Trail Making Test is timed and emphasizes, among other
things, visual scanning and sequencing).
What, then, defines "fluency performance"? Most attempts to objectively
define a cognitive concept are controversial. "Memory" is a prime example of
such a concept, as experimental psychologists, clinical psychologists, and
cognitive scientists rarely agree upon a widely accepted measure of memory
functioning. Because fluency is a relatively new and uninvestigated cognitive
concept, there is probably less debate surrounding its components. In our
measurement of fluency, we emphasize speed and nonstereotypic and initiative qualities. The initiative quality is measured by the number of unique designs generated, speed and the nonstereotypic quality are taken into account
by the timed aspect of the test and by the measurement of perseverated response styles. We believe that this format is in keeping with the original ideas
advanced by Jones-Gotman and Milner (1977) and is in keeping with current
neuropsychological parameters concerning fluency.
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