Biomedical subjects

Timo Ahonen

Publications and source records attributed to Timo Ahonen.

12 recordsLinked to original sources

PubMed2006

Early motor development and later language and reading skills in children at risk of familial dyslexia.

Relationships between early motor development and language and reading skills were studied in 154 children, of whom 75 had familial risk of dyslexia (37 females, 38 males; at-risk group) and 79 constituted a control group (32 females, 47 males). Motor development was assessed by a structured parental questionnaire during the child's first year of life. Vocabulary and inflectional morphology skills were used as early indicators of language skills at 3 years 6 months and 5 years or 5 years 6 months of age, and reading speed was used as a later indicator of reading skills at 7 years of age. The same subgroups as in our earlier study (in which the cluster analysis was described) were used in this study. The three subgroups of the control group were 'fast motor development', 'slow fine motor development', and 'slow gross motor development', and the two subgroups of the at-risk group were 'slow motor development' and 'fast motor development'. A significant difference was found between the development of expressive language skills. Children with familial risk of dyslexia and slow motor development had a smaller vocabulary with poorer inflectional skills than the other children. They were also slower in their reading speed at the end of the first grade at the age of 7 years. Two different associations are discussed, namely the connection between early motor development and language development, and the connection between early motor development and reading speed.

Child↗

PubMed2006

Basic numeracy in children with specific language impairment: heterogeneity and connections to language.

PURPOSE: This study examined basic numerical skills in children with specific language impairment (SLI) and how well linguistic factors explain the variance in these children's number skills. METHOD: The performance of children with SLI (n=29) was compared with that of typically developing children along a continuum ranging from preschool to 3rd grade (n=20, 47, 40, and 33). This facilitated both linguistic and educational age comparisons. To study number skills within the SLI group more closely, this group was divided into subgroups on the basis of their performance in verbal and nonverbal numerical skills. The performance of the different SLI subgroups on the linguistic and nonverbal reasoning task was analyzed. RESULTS: As a single group, the children with SLI lagged behind their educational age controls in both verbal and nonverbal numerical skills. Subgroup analyses revealed that the ability to retrieve arithmetic facts from the memory was connected to naming fluency, whereas the differences in nonverbal numerical skills were not explained by the cognitive skills measured (nonverbal reasoning skill, verbal short-term memory, vocabulary, comprehension, and naming fluency). CONCLUSIONS: This study demonstrates that children with SLI form a very heterogeneous group in their numerical skills, and thus specific hypotheses concerning the influence of linguistic deficits on developing numerical skills are required. The cognitive components of serial naming speed present a promising domain for further exploration.

Case-Control Studies↗

PubMed2006

Face description with local binary patterns: application to face recognition.

This paper presents a novel and efficient facial image representation based on local binary pattern (LBP) texture features. The face image is divided into several regions from which the LBP feature distributions are extracted and concatenated into an enhanced feature vector to be used as a face descriptor. The performance of the proposed method is assessed in the face recognition problem under different challenges. Other applications and several extensions are also discussed.

Algorithms↗

PubMed2006

The role of learning to read in the development of problem behaviour: a cross-lagged longitudinal study.

BACKGROUND: This study investigates the posited relationship between learning to read, and internalizing and externalizing problem behaviours, during the transition from preschool to primary school. METHODS: A total of 196 (104 boys, 92 girls) children participating in the Jyväskylä Entrance into Primary School (JEPS) study were followed up six times during their transition from preschool to primary school. At each measurement, the children's reading performance was tested. Moreover, their internalizing and externalizing problem behaviour was examined by means of structured interviews. RESULTS: The results showed that problems in reading acquisition predicted an increase in internalizing problem behaviour during the preschool year and first grade, whereas during the second grade they were associated with an increase in subsequent externalizing problem behaviour. Moreover, from preschool to the beginning of the primary school internalizing problem behaviour predicted subsequent externalizing problem behaviour. Later on during the first and the second primary school years, it was externalizing problem behaviour that predicted an increase in internalizing problem behaviour. CONCLUSIONS: The results of this study suggested that difficulties in learning to read, and internalizing and externalizing problem behaviours are developmentally linked in a cumulative manner.

Child↗

PubMed2006

The early motor milestones in infancy and later motor skills in toddlers: a structural equation model of motor development.

The relationship between the achievement of early motor milestones in infancy and later motor development was studied in 130 children with (N = 66, 35 male/31 female) and without (N = 64, 31 male/35 female) familial risk for dyslexia. A structured parental questionnaire was used to assess motor development in infancy, and the Movement Assessment Battery for Children was used to assess motor skills at age 3.5 years. No differences were found at the group level and therefore the structural equation model was constructed by entering both groups simultaneously. An Early Body Control factor, computed from the infant data, explained 38% of the variance of the Gross Motor Skills factor at the age of 3.5 years. The results suggest a relationship between gross motor milestones in infancy and gross motor skills in toddler age. Unexpectedly, the early appearance of Early Hand Control skills in infancy had a negative association with the development of the gross motor domain at 3.5 years (explanation ratio was 9%). No significant connections between early and later fine motor skills were found. The mediating role played by postural control is discussed.

Chi-Square Distribution↗

PubMed2005

Rapid serial naming: relations between different stimuli and neuropsychological factors.

We report two studies on rapid serial naming (RSN). Study 1 addressed the relations among RSN tasks comprising different stimuli. Separate components for RSN of alphanumeric and non-alphanumeric stimuli, as well as for tasks in which the stimuli alternated between categories were identified. In Study 2, phonological skills, processing speed, motor dexterity, and verbal fluency were found to explain RSN performance. The studies indicate: (1) that RSN tasks vary in their properties according to the stimuli used and according to the way the tasks are arranged, and (2) that RSN tasks are multi-componented.

Child↗

PubMed2004

Emerging phonological awareness differentiates children with and without familial risk for dyslexia after controlling for general language skills.

Emerging phonological awareness was compared in two groups of 3.5-year-old children belonging to the Jyväskylä Longitudinal Study of Dyslexia (JLD): children with familial risk of dyslexia (at-risk group n = 98) and children without such risk (control group n = 91). Four computer animated tasks were used: Word-level and Syllable-level Segment Identification, Synthesis, and Continuation of Phonological Units. The control group children manifested higher mastery than children in the at-risk group in phonological awareness, and the proportion of children with a low phonological awareness mean score was 2.5 times higher in the at-risk group than in the control group. In both groups, phonological awareness at 3.5 years was predicted by early language skills assessed between 14 and 26 months of age, and it was also associated with concurrent language. The difference between the at-risk and control group at 3.5-year in phonological awareness remained significant, even when the effect of other language skills such as productive and receptive vocabulary, and mastery of inflections, measured both at earlier ages and concurrently were controlled for. Our findings indicate that familial risk for dyslexia is reliably reflected in emerging phonological awareness already at this early age and it can be assessed independently of other language skills.

Articulation Disorders↗

PubMed2004

Co-occurrence of developmental delays in a screening study of 4-year-old Finnish children.

The aim of this population study was to examine the severity and prevalence of co-occurring developmental delays in 4-year-old children, the rate of overlapping problems, and sex differences. A sample of 434 children (196 males, 238 females; mean age 4 years 3 months, SD 1 month) were administered the 'Lene' test: a comprehensive neurodevelopmental screening test. Results suggest that co-occurrence of attention-behavioural, motor-perceptual, and language delays occurring in school-aged children could already be detected at the age of 4 years. Isolated delays were usually mild, but co-occurring difficulties were mostly moderate or severe. Overlap between developmental delays depended on the severity of the problems. It emerged that males had more severe and more often co-occurring problems than females. Co-occurrence of developmental delays as a risk factor at the early stage of development is discussed.

Catchment Area, Health↗

PubMed2003

Neurocognitive functioning in children with type-1 diabetes with and without episodes of severe hypoglycaemia.

Previous studies have shown that recurrent severe hypoglycaemia can cause long-term cognitive impairment in children with type-1 diabetes, but the results are controversial, possibly due to the heterogeneity of samples and lack of comprehensive neuropsychological assessments of children. The aim of this study was to assess the effects of diabetes and severe hypoglycaemia on the neurocognitive functioning of children with a standardized, wide age-range neuropsychological test battery designed for the assessment of children. Eleven children with diabetes and a history of severe hypoglycaemia, 10 children with diabetes without a history of severe hypoglycaemia, and 10 healthy control children (a total of 31 children: 14 males and 17 females, age range 5 years 6 months to 11 years 11 months, mean 9 years 4 months, SD 1 year 11 months) were studied using the Wechsler Intelligence Scale for Children-Revised (WISC-R) and the NEPSY, a Developmental Neuropsychological Assessment. The NEPSY assessed development in attention and executive functions, language, sensorimotor functions, visuospatial processing, and learning and memory. Children with a history of severe hypoglycaemia had more neuropsychological impairments, more learning difficulties (as reported by parents), and needed more part-time special education than those in the other groups. Significant differences were found in verbal short-term memory and phonological processing. Results suggest that severe hypoglycaemia is a risk factor for learning due to deficits in auditory-verbal functioning.

Child↗

PubMed2002

Familial dyslexia: neurocognitive and genetic correlation in a large Finnish family.

Neuropsychological findings of individuals with dyslexia (n=24) from a large, three-generation Finnish family are presented. We have previously performed whole genome linkage scanning in this family and found that dyslexia in this kindred segregates with a single locus in the pericentromeric area of chromosome 3. Those included in the analyses were carefully evaluated for general cognitive ability, reading and spelling skills, and reading-related neurocognitive skills. The neurocognitive type of dyslexia segregating in this family consisted of deficits in phonological awareness, verbal short-term memory, and rapid naming. Severe dyslexia also seemed to be connected with a general language difficulty and was most common in the eldest generation.

Adult↗

PubMed2002

Development of early motor skills and language in children at risk for familial dyslexia.

Differences in motor development and the relationship between motor and language development were studied in 88 children with familial risk for dyslexia (43 females, 45 males; at-risk group) and 88 children without familial risk for dyslexia (35 females, 53 females; control group; n=176) during the first two years of life. A structured parental questionnaire was used to assess motor development. Expressive language skills were assessed at the age of 18 months with the Reynell Developmental Language Scales and at 18 and 24 months with the MacArthur Communicative Development Inventories. At group level, the motor development of children in both the at-risk and control groups was similar. However, motor development showed a different pattern in these groups. Cluster analyses revealed three clusters in the control group: 'fast motor development', 'slow fine motor development', and 'slow gross motor development'. In the at-risk group, only two clusters were found: 'slow motor development' and 'fast motor development'. A significant difference (p=0.03) was found between the clusters in the MacArthur Communicative Development Inventories. Children with familial risk for dyslexia and slow motor development had a smaller vocabulary and produced shorter sentences than the all other children. Associations between motor and language difficulties are discussed.

Child↗

PubMedDate not supplied

Assessment of three-and-a-half-year-old children's emerging phonological awareness in a computer animation context.

Four computer-animated tasks were created to analyze the underlying structure of emerging phonological awareness at 3.5 years of age and to explore the factors that influence children's (N = 91) performance on the tasks. Our findings indicated that already at this young age, children are able to master tasks demanding identification, blending, and continuation of phonological units when the tasks are presented in a motivating assessment context. In line with earlier research, children showed higher mastery in dealing with words and syllables than in dealing with phonemes. Targets in the initial position of a word were easier for children to identify than those in the final position. Our analysis provided support for two major dimensions of emerging phonological awareness based on the cognitive operations of the tasks: identification and blending of phonological units.

Awareness↗