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Biomedical subjects

U Frith

Publications and source records attributed to U Frith.

At least 37 records · Page 2Linked to original sources

The cognitive basis of a biological disorder: autism.

This article summarizes recent evidence indicating that individuals suffering from autism have a specific problem in understanding intentions and beliefs. We propose that this problem arises because they are incapable of forming a special kind of mental representation. A single cognitive deficit defines what is common to all autistic individuals. In contrast there is a wide range of proposals for the biological origins of the disorder.

Autistic Disorder

Prospects for a cognitive neuropsychology of autism: Hobson's choice.

Leslie (1987b) proposed a new, metarepresentational model for the cognition of pretense. This model identified a cognitive component necessary for the normal development of a "theory of mind." In this article, the relation of the child's early affective sensitivities to this component is considered. Early affective sensitivities seem to be cognitively distinct from the metarepresentational component. Childhood autism provides an interesting opportunity to study this problem. Three theoretical possibilities for the pathogenesis of this condition are presented: (a) a basic affective disorder as proposed by Hobson (this issue, p. 114), (b) a basic affective disorder and a basic cognitive disorder jointly, and (c) a basic cognitive disorder. There is little evidence for Option a, and a growing body of evidence supports Option c. Option b is sidelined for the time being on grounds of parsimony. Leslie's original theoretical proposals are revised, and some resulting implications are presented for the future investigation of the cognitive neuropsychology of autism.

Autistic Disorder

A new look at language and communication in autism.

In this review the specific language and communication impairments of autistic individuals are discussed and contrasted with non-specific impairments. All the impairments that are unique to autism concern the use of language for the purpose of intentional (but not instrumental) communication. The specific communication failure can be identified with a limitation in the computing of relevance and as a lack of taking account of mental states. This is a consequence of a subtle, but far-reaching, cognitive dysfunction. The dysfunction is likely to involve the formation and use of second-order representations. The same problem also leads to specific impairment in social relationships and imaginative play.

Autistic Disorder

Exploration of the autistic child's theory of mind: knowledge, belief, and communication.

26 autistic children with mental ages of 3-13 years were tested on 3 tasks that are within the capability of 3- or 4-year-old normal children. The first task tested understanding of a mistaken belief. Children were shown a typical box of a certain brand of sweets, and they all thought that it contained that kind of sweet. To their surprise, however, the box contained something else. Yet, only 4 out of the 26 autistic children were able to anticipate that another child in the same situation would make the same mistake. In contrast, all but 1 of 12 children with specific language impairment, matched for mental age, understood that others would be as misled as they had been themselves. The autistic children were also tested for their ability to infer knowledge about the content of a container from having or not having looked inside. All 4 children who had passed the belief task and an additional 4 performed perfectly, but most failed. The third task assessed children's pragmatic ability to adjust their answers to provide new rather than repeat old information. Here, too, most autistic children seemed unable to reliably make the correct adjustment. These results confirm the hypothesis that autistic children have profound difficulty in taking account of mental states.

Adolescent

The understanding and use of interpersonal gestures by autistic and Down's syndrome children.

Autistic adolescents with mild, moderate, and severe degrees of mental retardation, Down's syndrome adolescents, and clinically normal 4-, 5-, and 6-year-old children were compared in their ability to understand a set of simple instrumental gestures. Almost all gestures were perfectly understood, that is, correctly responded to, by normal children from age 5 onwards, and by all the handicapped groups, regardless of diagnosis or degree of retardation. However, the ability to initiate such gestures on verbal request was generally less good, especially in the less able autistic groups. The same subjects were unobtrusively observed in the playground and during mealtime at their schools. Peer interactions were least frequent in the autistic subjects, regardless of degree of mental retardation. However, relative to interaction frequency, the autistic group used nonverbal instrumental gestures as a means of communication to the same extent as the other groups. Unlike Down's syndrome adolescents, or normal preschool children, no autistic adolescent ever used expressive gestures.

Adolescent

Comprehension in "hyperlexic" readers.

Mentally retarded children who can read aloud written words better than one would expect from their Mental Age are often called hyperlexic. The reading comprehension thought to be impaired in such children was investigated in four experiments. Mentally retarded advanced decoders, including autistic and nonautistic children, were compared with younger nonretarded children matched for Mental Age and Reading Age. Experiment 1 established that mildly mentally retarded readers could match sentences to pictures as well as could be expected from their verbal ability. This was the same whether they read the sentences or heard them. Experiment 2 demonstrated that only the more able retarded subjects, but not the less able ones, used sentence context in a normal way in order to pronounce homographs. Experiments 3 and 4 showed that these same more able children could extract meaning at both sentence and story level, and their performance was indistinguishable from that of normal controls. Hence, it is doubtful whether these advanced decoders should be called hyperlexic. In contrast, the readers of relatively low verbal ability performed much worse than their normal controls. Although they could be induced under certain conditions to read sentence-by-sentence rather than word-by-word, they did not do so spontaneously. Furthermore, they did not make use of already existing general knowledge in order to answer questions about the stories they had read. The ability to comprehend in terms of large units of meaning seems to be specifically impaired in these low verbal ability fluent readers. We suggest that it is this impairment that marks true hyperlexia. Since there were no differences between autistic and nonautistic readers on any of our tasks, we conclude that hyperlexia is not an autism-specific phenomenon.

Adolescent

An islet of ability in autistic children: a research note.

An aspect of cognitive functioning in autistic children was investigated by comparing their performance on the Children's Embedded Figures Test with that of MA-matched normal and MA- and CA-matched mentally retarded non-autistic children. The autistic children were significantly more competent at this task than either group of control children, and also showed qualitatively different strategies. Since the performance of the autistic children was better than predicted from MA and commensurate with CA, it can be regarded as an islet of ability. This finding is discussed in terms of orientation and visualization factors involved in visuo-spatial abilities and is also related to cognitive deficit.

Adolescent

Perceiving the language of films.

Children appear to be familiar with the language of film makers or at least to perceive and remember films less well when the rules of this cinematic language are broken. In this experiment a simple action sequence filmed from a static viewpoint was made up into two films of four shots. One film was edited according to the rules of directional continuity specified by Hollywood cinema, that is the four shots were presented so as to preserve the subject's direction of movement across cuts. The other film was edited disregarding these rules. Apart from this difference both films were identical. Children aged seven, nine, and thirteen years watched either of these films and reconstructed the action using pictures representing the four shots. The children who saw the conventional version were better able to reconstruct what they had seen than those who saw the unconventional version.

Adolescent