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Tansulu Mukhitdinova, MA (Psychology)
Alla
Kim, Dr.of Sciences (Psychology)
Performance on the Money Road Map Test of Directional Sense:
Effects of Age, Gender and Relevant
Spatial Experience
The Standardized
Money Road Map Test of Directional Sense (Money, Alexander & Walker, 1965)
is a paper and pencil assessment of left-right discrimination, that requires an
egocentric mental rotation in space. The stimulus for this test is a schematic
city map, with dotted route on it, which the subject is asked to trace, making
the discrimination of right and left turns. The subject is not allowed to turn
the map or make movements to give the correct answer.
Studies report significant
gender differences in performance on this test assessed in adult samples. A
number of investigations, analyzing Money Road Map Test performance, were
conducted in clinical groups with patients suffering from Alzheimer disease and
brain-damaged people. Guy Vangerhoets with colleagues (Guy Vangerhoets et al,
1996) point out that two different cognitive functions, the left-right
discrimination per se, and the ability to perform an egocentric mental rotation
in space, underlies the performance on Money Road Map Test. Studies give
evidence that performance on tasks which require egocentric mental rotation
(Money Road Map Test, Zimmerman’s Spatial Orientation Test and other egocentric
perspective-taking tests) usually shows high positive correlation with
allocentric mental rotation tasks (Vandenberg and Kuse’s MRT, Shepard and
Metzler’s MRT), so that factor analytic studies often fail to find any
significant difference between them. However recent behavioral investigations
give evidence that these are closely related but different abilities (Mary
Hegarty et al, 2004).
Gender
differences in spatial cognition have been well established and documented as a
reliable finding in the cognitive literature. Although the magnitude and effect
of reported gender differences varies across authors, males typically
outperform women in mental rotation and navigational tasks, regardless of the
experimental paradigm used by investigators (human or animal paradigm, real or
virtual reality settings). There are different theories, explaining these
differences from evolutionary, biological or socio-cultural standpoints,
however, the exact nature of these differences is not yet well understood. One
of the most influential current theories, a hunter-gatherer hypothesis (Silverman
and Eals, 1992) forms the conception of dimorphic sex-specific spatial
cognition, with navigational excellence of males, caused by competition for
resources, hunting and warfare, and female advantage in object location and
relational object location memory, evolved for food location and indicating the
location of offspring (Sarah Levine et al, 2005).
The current study
was addressing the following questions:
-
does male advantage on this task emerge in adolescence or
earlier?
-
does relevant spatial experience influence performance on
this task?
-
can motor activation of the right, “spatial”, hemisphere,
influence performance on this task in right-handed subjects?
Experiment
1
Based on the
evolutionary hunter-gatherer theory and evidence that performance on mental
rotation tasks is sensitive to the level of sex hormones in blood (Markus
Hausmann et al, 2000), we
predicted that male advantage on Money Road Map Test will appear after age of
12, when puberty forms the basis for sex-specific differences in spatial
cognition. It was also hypothesized that realism (using as a stimulus a real
map) will enhance the difference, because studies show that females are worse
than males at real map interpretation.
Subjects
126 healthy
children (64 girls and 62 boys), grouped by age 8, 10, 12 and 14, participated
in the experiment conducted as a part of annual psychological school assessment
procedure. Subjects were seated in front of the experimenter and tested
individually. The entire duration of the experiment, including Money Map Test
(Real and Schematic Maps), Mental Rotation Test and Short-Term Visuo-Spatial
Memory Test, was approximately 20 min. In this paper we report the data
obtained with Money Map Test.
Materials
and procedure
Money
Map Test
A modified
version of Money Road Map Test – “Money Map Test,” consisting of 2 separate
maps, one real and one schematic, was created for the experiment. A small part
of a real colored map of Almaty with an up-down route, containing 12 left and
12 right turns, marked on it, was used as Money Real Map Test. The same route
was replicated on a stylized schematic black-and-white map for Money Schematic
Map Test. Subjects were asked to follow the marked route both on the real map
and on the scheme and say at each turn whether they are “going” right or left.
They were told to fulfill the task as quickly as they could, but also as
accurate as possible. During the pilot study with 15 children (8-14 years of
age) it became evident that the children tended to omit small turns, so that
the experimenter could not discriminate and fix accurately their right and
wrong answers. Therefore minor changes were made to the standard testing
procedure – all turns were marked with numbers, and subjects were asked to name
the corresponding number and say “Right”, if they decided that they “were
taking” the right turn, or “Left”, if they decided that they “were going” left.
Additionally, 8 and 10-year-old subjects were given a small toy car “to drive”
along the route in order to make the task completely understandable for them.
Older subjects were asked to follow the route with their finger.
Subjects were
first given a practice trial during which they had to discriminate 5 turns (3
right and 2 left) on a separate short route. In the main testing condition
overall time taken to discriminate all 24 turns and the number or errors made
were recorded for 6 trials (3 for the real map condition and 3 for the
schematic map condition, separated by mental rotation task). The order of
trials was counterbalanced between subjects – one half of them were first
tested in the real map condition, the other – in the schematic map condition.
The study was
carried out following 2x2x4 experimental plan with 3 dependent variables –
performance on Money Real Map, Money Schematic Map and the mean score for both
of them (Money Mean), and 3 independent variables – Sex (2 levels), Group (2
levels) and Age (4 levels). The scores for Money Real and Schematic Map
variables are means of performance time of 3 sequential trials, with 2seconds
added for each error (one wrongly discriminated turn).
Results
and Discussion
We do not present here descriptive statistics for Money
Test because of the limitations of space. Since the error variance of the
dependent variables was significantly unequal across the groups of children (F(7,118)=14.090 p=. .000 for
the Real Map, F(7,118)=28.129,
p=. 000 for the Schematic Map, F(7,118)=16.881, p= .000 for
Money Mean), non-parametric Kruskal-Wallis one-way analysis of variance was
executed for 8 groups (8, 10, 12 and 14-year-old female and male samples).
Kruskal-Wallis H was significant for
all three dependent variables, Money Real Map – 63.961, p= .000, Money
Schematic Map – 56.326, p=. 000, Money Mean – 64.886, p= .000 (df=7), hence significant differences
between the groups, implying effects of age and gender, were assumed.
Individual
one-way ANOVAs were carried out in order to analyze whether the Group variable
(the order of presentation of the 2 maps – the schematic map preceded by the
real map (RS) and vice versa (SR)) had influenced the mean scores for the two
maps (Money Mean variable) and/or their individual scores. The order of
presentation did not have any significant effect (Money Real Map, F(1,124)= .691, p= .408,
Money Schematic Map, F(1,124)=2.496,
p= .117, Money Mean, F(1,124)=
.234, p= .629), so data were collapsed over this variable.
The analyses compared males and females performances showed
significant main effect of sex. Female and male performance at age 8 (Schematic
Map, Money Mean) and 10 (Real Map) was analyzed using Mann-Whitney U because of
significant Levene’s statistic for these variables.
Effect of gender
was found in all age groups, but the pattern of interaction between gender and
performance on Money Map Test, that was revealed in this study, proved to be
much more complex than it had been predicted. At the age of 8 the difference
between boys and girls, approaching significancy, U=76, p= .051 (one-tailed),
was found only for performance on the Money Schematic Map. 8-year-old girls
tended to perform better than boys, their mean rank for this type of map was
13,25 vs boys’ 19,75. This tendency became significant for 10-year-old
subjects, with girls outperforming boys both on the real (13.19 vs 19.81, p=
.047, one-tailed) and the schematic maps (mean difference 16.333, p= .027).
However, in the sample of 12-year-old subjects the relationship between gender
and Money test performance changed to the reverse, with boys significantly
outperforming girls on the Schematic Map (t=-15.629) and on the Real Map
(t=–12.606, approaching significancy). 14-year-old boys still performed better
than girls, but the mean difference between two sexes both for the real and
schematic map scores was smaller than in the previous age group.
Mann-Whitney Test
showed no significant difference in performance of 8 and 10-year old females, 8
and 10 year-old males, 12 and 14-year old females and 12 and 14-year old males,
so the data were consolidated in 4 sets accordingly, and analysed by individual one-way ANOVAs carried out for
each dependent variable, with Dunnett‘s T3 and Games-Howell Test used for the
post hoc between-age analysis.
Between-age
analysis gives evidence that 4 aggregated groups differ significantly on their
performance on Money Map Test. At the age 8-10 girls outperform boys, but after
that age the situation changes to the reverse. However, male advantage in 12-14
samples is not absolute: it only approaches significancy for Money Real Map
(t=-9.8978, p= .068) and is evident for Money Schematic Map (t=-12.8934, p=
.016) and Money Mean (t=-11.3961, p= .021). Our hypothesis that realism will
enhance gender differences was not confirmed, moreover, the main difference in
female and male performance on Money Test after age of 12 was revealed only in
schematic map condition. It should be noted that the original Money Road Map
Test is used only in schematic map form, hence the study highlights the fact
that ecological validity of stimuli used for spatial tests has cosiderable
methodological importance.
Experiment
2
It was supposed that relevant spatial experience influences performance on spatial tests. An fMRI study of London taxi drivers has shown that their professional experience had led to substantional changes in neurophysiological substrate of corresponding cognitive functions (Maguire, E.A. et al, 2000). On the other hand some investigations give evidence that professional experience is not always beneficial, for example, Corrine Jola (Corinne Jola et al, 2005) has shown that allocentric mental rotation ability is impaired in professional dancers. The main aim of Experiment 2 was to make clear whether gender differences in the MRMT performance might be less prominent than usually in some subjects due to their professional experience.
Method
Subjects
16 classic dancers (8 females, mean age 21.3±2.5, 8 males, mean age 23.5±2.8) and
20 undergraduate students (10 females, mean age 18.6±1.1, 10 males, mean age 19.6±1.0) took participation in the experiment as members of the
experimental and control groups. Subjects were seated in front of the experimenter
and tested individually. The entire duration of the experiment, including the
original Money Road Map Test, a mental
rotation test and a task for spatial orientation on imaginary matrices, was
approximately 30 min. Only the Money Road Map Test data is discussed here.
Materials
and procedure
The original schematic map of the Money Road Map Test was used. Subjects were given usual practice trial and then asked to discriminate and mark left and right turns of the dotted pathway on the map with “L” or “R” letters accordingly. They were instructed to do the task as fast as they could, and also as accurate as possible.
Time that it took each subject to fulfill the task was recorded. Each wrongly discriminated turn added 2 seconds to the overall time. Performance on Money Road Map Test was considered as dependent variable, sex (male vs female) and group (dancers vs non-dancers) as independent variables.
Results and Discussion
Significant effect of gender: F=9.16, p= .005 and not significant
effect of group (dancers vs non-dancers): F=1.30,
p= .262 were revealed. However, when gender and group were combined into one
united variable, its effect remained still quite significant (F=3.489, p= .027). Further post hoc
analysis using Bonferroni and Scheffe tests showed that statistically
significant difference was found only in performance of male dancers and female
non-dancers (t=-73.45, p= .036). LSD test gives statistically significant
difference in performance of both male and female dancers (t=-58.3750, p= .033)
and male and female students (t=-48.3000, p= .048). Nevertheless, it shows that
male students performed no significantly better than female dancers, t=-33.22,
p=.192.
Although the dancers advantage on
Money Road Map Test does not approach significance (p= .262), the female
dancers data show that professional experience might result in better
performance on this task.
Experiment
3
Driver’s job is considered as one of the
most “spatial” professions, since it poses considerable requirements to spatial
abilities and loads greatly on visuo-spatial cognitive functions. Therefore it
was assumed that even non-professional drivers will show better peformance on
the Money Road Map Test, compared with non-drivers, who do not have do decide
more or less regularly and more or less quickly which direction, left or right,
to take. Obviously, pedestrians do choose what direction to take, but they are
not required to do it as fast as drivers, who move with much more
high speed. We
were also interested whether the performance on the MRMT is sensible to the
hand, used for tracing the dotted pathway of the test. It was hypothesized that
right-handers may be more effective (performance times will be shorter and/or
errors fewer), when using their left hand, which is controlled by the right,
“spatial”, hemisphere.
Method
Subjects
13 male non-drivers and 14 male non-professional drivers participated in
the experiment. Driving experience of members of drivers group varied from 1 to
4 years. Subjects were
seated in front of the experimenter and tested individually. The entire
duration of the experiment, including the original Money Road Map Test, a
mental rotation test and a direction pointing task, was approximately 25 min.
Only the Money Road Map Test data is discussed here.
Right-handedness of all subjects approached 75 per cent and higher as assessed
by the Edinburgh Handedness Questionnaire.
Materials
and procedure
The original Money Road Map Test
(MRMT) stimulus with minor changes added was used.
All subject were randomly distributed
into 4 experimental groups: RL non-drivers (mean age 22.7±1.8), RL drivers (mean age 21.6±1.9), LR non-drivers (mean age 23.1±1.8) and LR drivers (23.7±2.3). In RL groups subjects were asked to trace the
dotted pathway on the map with a finger of their right hand first (3 successive
trials). They were then given a mental rotation task, followed by 3 trials on
the MRMT, using a finger of their left hand. This order was inverse for LR
groups. In order to record correctly all answers, all turns on the map were
numbered, and subjects were asked to name the corresponding number first, and
to give then their answer.
Scores for “MRMT-left” and
“MRMT-right” dependent variables were mean times for corresponding 3 trials,
with 2 seconds added per each error. The
first hand used for performance (right vs left), and driving experience
(drivers vs non-drivers) were considered as independent variables.
Results and Discussion
Significant effects of both the order
of trials (RL vs LR): F=11.42, p= .003 and driving experience: F= 8.48, p= .008
on mean score for all 6 trials were revealed. The interaction of these factors
was not significant. LR drivers were found to have the most advantage in mean
scores on the MRMT, performing better than both RL drivers (t=-19.58, p= .017)
and RL non-drivers (t=-25.40, p= .000), whereas no significant difference in
performance of drivers and non-drivers was found in LR group, irrelevant of the
hand used. This result testifies that the advantage of LR drivers over RL
drivers cannot be ascribed only to the individual differences in their driving
experience, which could occasionally be more extensive in this group.
Non-drivers of LR group performed the
task significantly better than RL non-drivers after they had “left-handed”
trials, t=-18.4671, p= .048, and slightly but not significantly better than RL
drivers, t=-9.7143, p=.448. Performance of LR non-drivers on the first 3 trials
did not differ significantly from the results of the first 3 trials of RL
non-drivers, that is the advantage of the former cannot be explained by
occasionally better developed egocentric mental rotation ability.
In conclusion it should be noted that
although the effect of driving experience per se is quite significant (F=6.720, p= . 016 for the MRMT performed
with the right hand, F=6.762, p= .016
for the “left-handed” MRMT and F=8.484, p= .008 for the mean scores of
the two), effect of the order of trials is much more stronger (F=27.025, p= .000 for the MRMT-right
hand, F=11.142, p=.003 for the mean
of the MRMT-right and MRMT-left), whereas the interaction of the factors is
small and unsignificant (F=.060,
p=.809, F=4.205, p=.052, F=2.193, p=.152). Hence the test is
likely to be sensible to motor activation of the right hemisphere of the brain.
Conclusions
The
main findings
of this research, in
line with a number of studies of gender differences in visuo-spatial ability,
highlight complex and dynamic nature of individual differences in spatial
cognition. Male superiority in egocentric
perspective taking, coupled with imaginary bodily rotation, as
assessed by a modified version of the Money Road Map Test, is likely to become evident after age of 12.
Surprisingly, female advantage on this task is revealed in younger children. Relevant
spatial experience has been shown to enhance both male and female performance
on the original MRMT. The question remains whether females can be trained so
that the level of their performance will achieve that of males. More research
is needed to clarify these findings and answer to many other questions still
remaining unanswered.
References
1. Vingerhoets, G., Lannoo, E.,
and Bauwensm S. (1996). Analysis of the Money Road-Map Test Performance
in Normal and Brain-Damaged Subjects. Archives
of Clinical Neuropsychology. Vol. 11, No. 1, pp. l-9.
2. Hegarty, M., and Waller, D. (2004).
A dissociation between mental rotation and perspective-taking spatial
abilities. Intelligence, No 32, pp. 175–191.
3. Levin, S., Mohamed, F.B., and Platek, S.M. (2005).
Common ground for spatial cognition? A behavioral and fMRI study of sex
differences in mental rotation and spatial working memory. Evolutionary Psychology. No 3, pp. 227-254.
4. Hausmann, M.,
Slabbekoorn D., Van Goozen, S., Cohen-Kettenis, P., and
Güntürkün, O. (2000). Sex Hormones Affect Spatial Abilities
During the Menstrual Cycle. Behavioral
Neuroscience, Vol. 114, No. 6, pp. 1245-1250.
5. Maguire, E.A., Gadian, D.G., Johnsrude, I.S., Good, C.D., Ashburner, J., Frackowiak, R.S., and Frith, C.D. (2000). Navigation-related structural change in the hippocampi of taxi drivers. Proceedings of the National Academy of Sciences of the USA, 97, pp. 4398-4403.
6. Jola, C., and Mast, F.W. (2005). Mental Object Rotation and Egocentric Body Transformation: Two Dissociable Processes? Spatial Cognition and Computation, Vol.5, Issue 2&3, pp. 217-237.