Biomedical subjects

Lars Smith

Publications and source records attributed to Lars Smith.

8 recordsLinked to original sources

PubMed2007

Response times of children and adolescents with Asperger syndrome on an 'advanced' test of theory of mind.

In the present study the response times of 10- to 20-year-old participants with Asperger syndrome (AS) (N=21) of normal intelligence and a control group of typically developing individuals (N=20) were recorded on a new 'advanced' test of theory of mind. This test taps the ability to make mental-state inferences versus physical-state inferences in a story context. The participants with AS were significantly slower than the controls on both tasks. In addition, the differences in response times between mental- and physical-state inference were significantly larger in the AS group than in the control group, suggesting that the clinical group experienced more problems than the controls in making inferences about mental states than about physical states.

Adolescent↗

PubMed2007

Disembedding performance in children and adolescents with Asperger syndrome or high-functioning autism.

The aim of the present study was to assess the findings, reported in earlier studies, that individuals with autism spectrum disorders process visuo-spatial tasks faster than typically developing control persons. The participants in the present study were children and adolescents with Asperger syndrome (AS) or high-functioning autism (HFA) (N = 13), and a matched group of typically developing children and adolescents (N = 13). The results showed that the participants in the clinical group performed marginally less well than those in the control group on both the Block Design Test and the Embedded Figures Test, but the differences were not statistically significant. Thus, earlier findings suggesting that individuals with autism spectrum disorders solve non-social cognitive tasks faster than typically developing control persons were not replicated. The results are discussed with special reference to the hypothesis of weak central coherence.

Adolescent↗

PubMed2006

Infant recall memory and communication predicts later cognitive development.

This longitudinal study investigates the relation between recall memory and communication in infancy and later cognitive development. Twenty-six typically developing Swedish children were tested during infancy for deferred imitation (memory), joint attention (JA), and requesting (nonverbal communication); they also were tested during childhood for language and cognitive competence. Results showed that infants with low performance on both deferred imitation at 9 months and joint attention at 14 months obtained a significantly lower score on a test of cognitive abilities at 4 years of age. This long-term prediction from preverbal infancy to childhood cognition is of interest both to developmental theory and to practice.

Child Development↗

PubMed2006

Exploring the Relation Between Memory, Gestural Communication, and the Emergence of Language in Infancy: A Longitudinal Study.

The relationship between recall memory, visual recognition memory, social communication, and the emergence of language skills was measured in a longitudinal study. Thirty typically developing Swedish children were tested at 6, 9 and 14 months. The result showed that, in combination, visual recognition memory at 6 months, deferred imitation at 9 months and turn-taking skills at 14 months could explain 41% of the variance in the infants' production of communicative gestures as measured by a Swedish variant of the MacArthur Communicative Development Inventories (CDI). In this statistical model, deferred imitation stood out as the strongest predictor.

Journal Article↗

PubMed2005

The Strange Stories test--a replication study of children and adolescents with Asperger syndrome.

The aim of the present study was to assess the ability of 21 children and adolescents with Asperger syndrome (AS) of normal intelligence to infer mental states in a story context using Happe's Strange Stories test. The participants in the AS group were compared with an age-matched control group (N=20) of normally developing children and adolescents on a test of social understanding. The test material comprised social communication such as Pretence, Joke, Lie, White Lie, Figure of Speech, Misunderstanding, Persuasion, Irony, Double Bluff and Contrary Emotions, Appearance/Reality and Forgetting. As compared to the controls, the participants in the AS group performed less well on these tasks, and answered fewer correct mental state inferences, but performed well on a physical state control task. This study supports the main finding of earlier studies, showing that even individuals with AS of normal intelligence have problems in using mental state terms context-appropriately when tested on the Strange Stories test.

Adolescent↗

PubMed2003

Maternal supplementation with very-long-chain n-3 fatty acids during pregnancy and lactation augments children's IQ at 4 years of age.

OBJECTIVES: Docosahexaenoic acid (DHA; 22:6 n-3) and arachidonic acid (AA; 20:4 n-6) are important for development of the central nervous system in mammals. There is a growth spurt in the human brain during the last trimester of pregnancy and the first postnatal months, with a large increase in the cerebral content of AA and DHA. The fetus and the newborn infant depend on maternal supply of DHA and AA. Our hypothesis was that maternal intake of DHA during pregnancy and lactation is marginal and that high intake of this fatty acid would benefit the child. We examined the effect of supplementing pregnant and lactating women with very-long-chain n-3 polyunsaturated fatty acids (PUFAs; cod liver oil) on mental development of the children, compared with maternal supplementation with long-chain n-6 PUFAs (corn oil). METHODS: The study was randomized and double-blinded. Pregnant women were recruited in week 18 of pregnancy to take 10 mL of cod liver oil or corn oil until 3 months after delivery. The cod liver oil contained 1183 mg/10 mL DHA, 803 mg/10 mL eicosapentaenoic acid (20:5 n-3), and a total of 2494 mg/10 mL summation operator n-3 PUFAs. The corn oil contained 4747 mg/10 mL linoleic acid (18:2 n-6) and 92 mg/10 mL alpha-linolenic acid (18:3 n-3). The amount of fat-soluble vitamins was identical in the 2 oils (117 micro g/mL vitamin A, 1 micro g/mL vitamin D, and 1.4 mg/mL dl-alpha-tocopherol). A total of 590 pregnant women were recruited to the study, and 341 mothers took part in the study until giving birth. All infants of these women were scheduled for assessment of cognitive function at 6 and 9 months of age, and 262 complied with the request. As part of the protocol, 135 subjects from this population were invited for intelligence testing with the Kaufman Assessment Battery for Children (K-ABC) at 4 years of age. Of the 135 invited children, 90 came for assessment. Six children did not complete the examination. The K-ABC is a measure of intelligence and achievement designed for children aged 2.5 years through 12.5 years. This multisubtest battery comprises 4 scales: Sequential Processing, Simultaneous Processing, Achievement (not used in the present study), and Nonverbal Abilities. The Sequential Processing and Simultaneous Processing scales are hypothesized to reflect the child's style of problem solving and information processing. Scores from these 2 scales are combined to form a Mental Processing Composite, which serves as the measure of intelligence in the K-ABC. RESULTS: We received dietary information from 76 infants (41 in the cod liver oil group and 35 in the corn oil group), documenting that all of them were breastfed at 3 months of age. Children who were born to mothers who had taken cod liver oil (n = 48) during pregnancy and lactation scored higher on the Mental Processing Composite of the K-ABC at 4 years of age as compared with children whose mothers had taken corn oil (n = 36; 106.4 [7.4] vs 102.3 [11.3]). The Mental Processing Composite score correlated significantly with head circumference at birth (r = 0.23), but no relation was found with birth weight or gestational length. The children's mental processing scores at 4 years of age correlated significantly with maternal intake of DHA and eicosapentaenoic acid during pregnancy. In a multiple regression model, maternal intake of DHA during pregnancy was the only variable of statistical significance for the children's mental processing scores at 4 years of age. CONCLUSION: Maternal intake of very-long-chain n-3 PUFAs during pregnancy and lactation may be favorable for later mental development of children.

Breast Feeding↗

PubMed2002

Temperament in children with Down syndrome and in prematurely born children.

Parents of three groups of children completed the Children's Behavior Questionnaire (CBQ). Participants were children with Down syndrome aged 4-11 years (n = 55), prematurely born children aged 5 years (n = 97), and a group of normally developing kindergarten children 5-7 years of age (n = 91). Mean levels and factor structures on the CBQ were compared between the three groups. The children with Down syndrome had less attentional focusing and expressed less inhibitory control and less sadness than the normally developing children. There were also group differences in temperament structures, especially a clearer emotional factor of "surgency" among the children with Down syndrome. The only significant difference in mean temperament scores between the premature children and the control group was that the former evinced less attentional focussing. The temperament structures in the Norwegian samples were very similar to those reported in earlier studies, conducted in China and the US.

Child↗

PubMed2002

A new 'advanced' test of theory of mind: evidence from children and adolescents with Asperger syndrome.

BACKGROUND: The aim of the present study was to assess the ability of children and adolescents with Asperger syndrome (AS) (N = 21) to infer physical versus mental states on a new 'advanced' test of theory-of-mind - Stories from Everyday Life. The participants in the AS group were of normal intelligence and were compared with an age-matched control group (N = 20) of normally developing children and adolescents. METHOD: The test materials comprised 26 short stories or 13 pairs of different types of stories. This contextually complex theory-of-mind battery aimed to record the participants' ability to make inferences about physical as well as mental states. The first part of each story described a physical or mechanical event, and a test question then tested the participants' ability to make an inference about a physical state. The last part of the stories contained two questions, testing the ability to infer a mental state from the story context, e.g., understanding social communication such as a lie, white lie, figure of speech, misunderstanding, double bluff, irony, persuasion, contrary emotions, forgetting, jealousy, intentions, empathy and social blunders. The participants' reaction time and number of prompt questions were also recorded. RESULTS: The participants in the AS group showed significantly more problems attributing mental state inferences relative to the control group. They performed considerably better on tasks involving a physical state, but still did less well than the controls. They had a tendency to interpret behaviour and utterances literally, without regard to context, and to choose a physical explanation when a mental state answer was more appropriate. They also needed significantly more prompt questions and used significantly more time than the controls to solve the tasks, especially those involving mental state inference. CONCLUSIONS: This study supports earlier findings that individuals with AS/HFA have difficulties attributing mental states in context, but seem to have significantly fewer difficulties inferring physical states. The fact that the clinical group also used significant longer reaction time and needed significantly more prompt questions to solve the tasks relative to the control group may also be related to their problems in understanding mental states. However, the possibility remains that these difficulties could represent a separate factor - or a distinct 'cognitive style'- suggesting that at least some individuals with AS may be generally slow in solving cognitive tasks.

Adolescent↗