Brief report: Developing theory of mind abilities and other cognitive skills
in autism
Author:
Dr Evelyn McGregor - University of St. Andrews, Scotland
Dr Evelyn McGregor is a lecturer in developmental psychology at the University of St. Andrews.
Her interests are in socio-cognitive development in autism and typical development. Her research
work includes narrative in autism, in particular narrative fluency and narrative dependency during
cognitive tasks, understanding of representation in typical and atypical child populations and
attitudes to the inclusion of children with learning disabilities into mainstream education. She is a
founder member of the Scottish Autism Research Group (SARG), an inter-disciplinary forum for
researchers and practitioners. SARG is currently running a seminar series, 'An Integrated View of
Research on Autism: Bringing Together Neurocognitive, Clinical/Diagnostic and Educational
Processes,' funded by the ESRC (details are at: www.education.ed.ac.uk/sarg).
Abstract:
By Dr Evelyn McGregor
University of St. Andrews
There has been considerable speculation about the nature of the theory of mind difficulty in
autism, including whether children have a deficit or delay in understanding mind. Cross-sectional
findings have indicated delay, and some research also suggests that mental state abilities are
linked to non-mental state, but there has been little longitudinal research and results are
inconsistent. The present study followed up 17 children with autism three years after initial
testing on mental state and non-mental state tasks, and language tests. A comparison of scores
showed a statistically significant increase in scores for mental state tasks and language tests,
both verbal mental age and standard scores, but improvement on other cognitive tasks was
uneven. These findings indicate development of mental state understanding, supporting the delay
hypothesis, with associated development of some non-social abilities. However, some children
did not improve, indicating variety across the spectrum.
Address for correspondence:
Dr Evelyn McGregor,
School of Psychology,
University of St. Andrews,
St. Andrews,
Fife
Full Paper:
INTRODUCTION
The aims of the present study were to test longitudinally the hypothesis that theory of mind
understanding may be delayed in autism; and to test for any accompanying development of nonsocial cognitive features of autism.
One framework for understanding the social deficits of autism is to attribute them to a lack of
'theory of mind' abilities, assessed by story-based tests of understanding mental states. A
commonly used test requires that the child can attribute a false belief to a story character.
Although the majority of typical 4-year-olds and children with Down syndrome with a verbal age of
above 4 years can pass these tasks, the majority of children with autism of similar verbal mental
age cannot do so (Baron-Cohen, Leslie & Frith, 1985; Sodian & Frith, 1992). It has been noted
that those who do pass the tests have a higher chronological and verbal mental age than typical
samples (Baron-Cohen, 1989; Happe, 1994). This suggests that at least some of the children
may have a delay rather than a deficit in developing theory of mind abilities, but also that
acquisition is linked to developing verbal abilities.
Baron-Cohen (1989) found that the able children with autism who passed the 'first-order' test
failed a more complex test of second-order belief attribution, though 90% of typical 7-year-olds
passed. He concluded that children with autism have a specific developmental delay relative to
both their chronological and their mental age, postulating that the sample of children who passed
were on average seven years later than their typical counterparts. However, he noted that the
strongest test of the hypothesis would rely on longitudinal data.
Three longitudinal studies have been conducted. Holroyd and Baron-Cohen (1993) followed up
17 of their sample from the original study of false belief (1985) seven years on. In addition,
Ozonoff and McEvoy (1994) followed up 17 participants after three years. Neither study found
significant improvement. However, Steele, Joseph and Tager-Flusberg (2003) re-tested a sample
of younger children with autism after a year, and found that 70% improved at the second time of
testing. They identified two possible reasons why the results differed from those of the previous
studies: (1) the earlier samples were adolescent at the first time of testing leaving less
opportunity for development of such skills. (2) Steele et al. used a battery of developmentally
sequenced mental state tests which gave a composite score, thus picking up degrees of
improvement in understanding. They also found an association between language ability and
improvement on scores for the mental state tasks.
Steele et al.’s findings give grounds for optimism that for at least some children with autism, the
issue is one of developmental delay rather than deficit in ability to understand mental states under
test conditions. The present study was conducted prior to the publication of the report by Steele
et al., so is not a replication. However, given that the number of longitudinal studies is so small,
testing conditions different and findings inconsistent, the reporting of this study makes a further
contribution to the topic. The conditions under which this study was conducted were similar to
those of Steele et al. in two respects: the particpants were relatively young at the first time of
testing and other, non-social tests were included. They also ressembled the earlier studies in two
respects: the tasks used were conventional false belief tasks without any developmental
component, and the interval between tests was three years, the rationale being that this would
allow time for children to show change on a standard task. The test battery differed from that of
Steele et al., providing further scope for understanding false belief within a wider frame of
cognitive development. The battery included tests of understanding non-mental representation
(false photo tasks (Zaitchik, 1990; Leekam & Perner, 1991; Charman & Baron-Cohen, 1992) and
tests of vocabulary and grammar. In addition, test scores were compared on the memory and
reality control questions for the sets of cognitive tasks.
The study aimed to establish (1) whether there was an improvement in performance on false
belief tasks between time one and time two; (2) whether there were improved scores on nonsocial measures.
METHOD
Participants
There were 17 participants, 12 boys and 5 girls, with a mean CA of 8 years 11 months (SD = 2
years 8 months) and mean verbal mental age of 6 years 8 months (SD = 2 years 3 months) at
first time of testing. All the children attended specialist units attached to mainstream state
schools. Fifteen had a diagnosis of autism and two of Asperger’s syndrome. Diagnosis was
confirmed from school records and had been made by clinical specialists.
Design
The children were tested on two occasions three years apart with the same experimenter and
same materials. On each occasion, the children were given tests of verbal ability using the British
Picture Vocabulary Test and the Test for the Reception of Grammar. They were then shown two
sets of six short stories on video using child actors. One set of stories were false belief stories
and the other set were false photo stories, a control task that does not require mentalising ability
(Zaitchik, 1990; Leekam & Perner, 1991). Order of presentation was counterbalanced across the
groups. There were six paired storylines, with the false photo stories matched to their false belief
counterparts, centering round the same theme and filmed in the same location. Each story lasted
between one and two minutes and the children saw the false belief and false photo stories on
separate occasions.
Materials
Testing required a portable television, with a 24 cm screen and remote control; a video recorder
and videotapes of the twelve stories; a Polaroid camera and photos of the four child actors with
their names written underneath.
Procedure
The experimenter introduced the children to the use of a Polaroid camera and administered the
language tests. On the next visit, the experimenter sat with the participant in front of the
television and video recorder and explained that she was going to show him or her some stories
on film and that all the stories were about the same four children. The experimenter showed the
participant the photos of the child actors and encouraged them to identify each actor. The
experimenter then ran the tape to show the first story for that set, pausing at the appropriate point
to ask the test questions: 'Where will A (the actor) look first for X?' for the false belief condition or
'In the photo, where is X?' for the false photo condition. The false belief and false photo
questions were followed with reality and memory questions. The participants were asked 'Where
is X now?' and 'Where was X before, at the beginning of the story?'. When the child had seen
their first set of six stories, either false belief or false photo, the session ended. At the next
session, usually the following day, the child was shown the second set of six stories. Each child
therefore had a score out of six for the false belief tasks and a score out of six for the false photo
tasks. A composite score was also calculated for their performance overall on the pairs of control
questions for the twelve tasks. That is, if the child answered both control questions correctly they
received a score of 1. If they failed either, they were given a score of 0.
RESULTS
False Belief Scores
The first aim was to discover whether the group were better able to pass false belief tasks at
Time 2 than at Time 1. A Wilcoxon test showed that the group had improved over the three year
period (see Table 1): performance was significantly better at Time 2 than at Time 1 (z = 2.52, p
< 0.01). Four children showed little or no improvement and one was worse.
False Photo Scores
The second aim was to find out whether the group were better on the non-social measures at the
second time of testing. A Wilcoxon test showed the children achieved significantly higher scores
at Time 2 on the false photo tasks (z = 2.55, p < 0.01). (See Table 1). It should be noted that,
in contrast to earlier reports of performance on this task by children with autism, the participants
did not perform well on the false photo tasks at the first time of testing. The video presentation
format is likely to account for this. A close comparison of the components of the traditional
presentation method with the current video-based one revealed subtle but probably crucial
differences. In the video format, the task remains a non-mentalising one, but with a higher
executive demand than the format of earlier studies, in which all elements had been visible and
the child has access to the picture content initially (see McGregor & Bennett, in press). For the
purposes of the present study, the task serves as a comparison task for the false belief task, with
a similar executive load.
Language Scores
Language scores showed a statistically significant increase over the period on two separate
measures, the verbal mental age scores and the standard score equivalents. For the verbal
mental age BPVS scores, Wilcoxon z = 3.62, p < 0.001. For the TROG scores, z = 3.13, p <
0.01. For standard score equivalents, BPVS z = 2.06, p < 0.04; TROG z = 1.7, p < 0.09 (see
Table 1). Both sets of scores were highly correlated for Time 1 to Time 2 (see Table 2). A
significant improvement was to be expected of verbal mental age scores, but not necessarily
expected of standard scores. This is because BPVS scores are calculated on a simple scale and
as the child increases in age one would hope to see an increase in the score, indicating some
language development. However, standard score equivalents score the child relative to his or her
age peers. So if the score increases, it indicates that the child has improved relative to others his
age. However, the improvement should be viewed with caution, as it was only marginally
significant for the BPVS, and given that seven tests were conducted in all, p-values greater than
0.01 could be due to chance.
Memory and Reality Scores
Group scores on pairs of memory and reality responses showed no statistically significant
difference overall (see Table 1). However, when the participants were separated into two subgroups according to language ability and those data were analysed separately, the results
showed that the high ability children (TROG > 5 years 9 months, N = 8) had a higher mean score
on control questions. They showed no improvement from T1 to T2 because they were close to
the ceiling of 12 pairs of answers correct on both occasions. By contrast, the low language ability
group (TROG < 5 years 6 months, N = 9) did show an improvement between T1 and T2 (see
Table 3) and the difference was significant (t = 13.2, df = 8, p < 0.001).
DISCUSSION
The results of this longitudinal study support cross-sectional indications of a delay in theory of
mind development and the findings of Steele et al. (2003) and support their rationale that there is
greater chance of positive change in younger samples of children. The group overall showed a
statistically significant improvement in performance at Time 2 compared with Time 1. Although
seven children achieved the same performance three years on, and three only marginally better,
only one child was worse at the second time of testing. This finding has two possible
interpretations: either that some children have a delay in their understanding of mind as
measured by the false belief task; or else that increasing maturity and improved language skill –
and memory and attention skills in the case of the less able group - enable them to devise an
effective strategy for passing the task.
The group were also better at non-social cognitive tasks. They were significantly better at
passing the false photo task three years on, a task which, in video format, required attention and
reasoning about the non-visible image in the photograph. In addition, they achieved higher
scores on both sets of language tests. Although it is to be expected that they would improve
according to the verbal mental age measure, since they were now three years older, it is
encouraging to note that they also showed a statistically significant improvement on the standard
score equivalent for the BPVS, an indication of real improvement relative to their age group and a
trend to improvement on the TROG. However, since probabilities are borderline and several
tests were conducted, corroboration would need to be sought for this finding.
The less able sub-group of children also showed an improvement on their scores for the pairs of
memory and reality questions. The more able children had shown little difficulty with these
questions at Time 1, so there was no scope for improvement on those simple tests. However, it
indicates that some children with autism show positive development across a range of social and
non-social measures. It also indicates varying patterns of development within the autism
spectrum rather than degrees of difference, supporting cross-sectional evidence (Joseph and
Tager-Flusberg, 2004).
The findings suggest that many children with autism progress in general cognitive measures and
mental state understanding. However, development is slower than in typical development, some
children do not improve and the difference in a matching improvement on pairs of control
questions between children with higher and lower verbal ability indicates that patterns of
development vary. More able children may also improve their memory and attention skills, but a
more demanding test would need to be given to explore this. Future work needs to explore
longitudinally the effect of non-social features of autism such as memory and attention on social
and intellectual development and the variation of development within the autism spectrum.
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