Visuaalis-spatiaalisten työmuistivalmiuksien yhteys (esi)matemaattisiin taitoihin ja merkitys osana matemaattisilta taidoiltaan heikkojen lasten ja nuorten kognitiivista profiilia

Tämän itsenäisistä osatutkimuksista koostuvan tutkimussarjan tavoitteena oli pyrkiä täydentämään kuvaa matemaattisilta taidoiltaan heikkojen lasten ja nuorten tiedonkäsittelyvalmiuksista selvittämällä, ovatko visuaalis-spatiaaliset työmuistivalmiudet yhteydessä matemaattiseen suoriutumiseen. Teoreettinen viitekehys rakentui Baddeleyn (1986, 1997) kolmikomponenttimallin ympärille. Työmuistikäsitys oli kuitenkin esikuvaansa laajempi sisällyttäen visuaalis-spatiaaliseen työmuistiin Cornoldin ja Vecchin (2003) termein sekä passiiviset varastotoiminnot että aktiiviset prosessointitoiminnot. Yhteyksiä työmuistin ja matemaattisten taitojen välillä tarkasteltiin viiden eri osatutkimuksen avulla. Kaksi ensimmäistä keskittyivät alle kouluikäisten lukukäsitteen hallinnan ja visuaalis-spatiaalisten työmuistivalmiuksen tutkimiseen ja kolme jälkimmäistä peruskoulun yhdeksäsluokkalaisten matemaattisten taitojen ja visuaalis-spatiaalisten työmuistitaitojen välisten yhteyksien selvittämiseen. Tutkimussarjan avulla pyrittiin selvittämään, ovatko visuaalis-spatiaaliset työmuistivalmiudet yhteydessä matemaattiseen suoriutumiseen sekä esi- että yläkouluiässä (osatutkimukset I, II, III, IV, V), onko yhteys spesifi rajoittuen tiettyjen visuaalis-spatiaalisten valmiuksien ja matemaattisen suoriutumisen välille vai onko se yleinen koskien matemaattisia taitoja ja koko visuaalis-spatiaalista työmuistia (osatutkimukset I, II, III, IV, V) tai työmuistia laajemmin (osatutkimukset II, III) sekä onko yhteys työmuistispesifi vai selitettävissä älykkyyden kaltaisella yleisellä päättelykapasiteetilla (osatutkimukset I, II, IV). Tutkimussarjan tulokset osoittavat, että kyky säilyttää ja käsitellä hetkellisesti visuaalis-spatiaalista informaatiota on yhteydessä matemaattiseen suoriutumiseen eikä yhteyttä voida selittää yksinomaan joustavalla älykkyydellä. Suoriutuminen visuaalis-spatiaalista työmuistia mittaavissa tehtävissä on yhteydessä sekä alle kouluikäisten esimatemaattisten taitojen hallintaan että peruskoulun yhdeksäsluokkalaisten matematiikan taitoihin. Matemaattisilta taidoiltaan heikkojen lasten ja nuorten visuaalis-spatiaalisten työmuistiresurssien heikkoudet vaikuttavat kuitenkin olevan sangen spesifejä rajoittuen tietyntyyppisissä muistitehtävissä vaadittaviin valmiuksiin; kaikissa visuaalis-spatiaalisen työmuistin valmiuksia mittaavissa tehtävissä suoriutuminen ei ole yhteydessä matemaattisiin taitoihin. Työmuistivalmiuksissa ilmenevät erot sekä alle kouluikäisten että kouluikäisten matemaattisilta taidoiltaan heikkojen ja normaalisuoriutujien välillä näyttävät olevan kuitenkin jossain määrin yhteydessä kielellisiin taitoihin viitaten vaikeuksien tietynlaiseen kasautumiseen; niillä matemaattisesti heikoilla, joilla on myös kielellisiä vaikeuksia, on keskimäärin laajemmat työmuistiheikkoudet. Osalla matematiikassa heikosti suoriutuvista on näin ollen selvästi keskimääräistä heikommat visuaalis-spatiaaliset työmuistivalmiudet, ja tämä heikkous saattaa olla yksi mahdollinen syy tai vaikeuksia lisäävä tekijä heikon matemaattisen suoriutumisen taustalla. Visuaalis-spatiaalisen työmuistin heikkous merkitsee konkreettisesti vähemmän mentaalista prosessointitilaa, joka rajoittaa oppimista ja suoritustilanteita. Tiedonkäsittelyvalmiuksien heikkous liittyy nimenomaan oppimisnopeuteen, ei asioiden opittavuuteen sinänsä. Mikäli oppimisympäristö ottaa huomioon valmiuksien rajallisuuden, työmuistiheikkoudet eivät todennäköisesti estä asioiden oppimista sinänsä. Avainsanat: Työmuisti, visuaalis-spatiaalinen työmuisti, matemaattiset taidot, lukukäsite, matematiikan oppimisvaikeudet

Developmental, functional brain imaging and electrophysiological evidence of visual and auditory working memory

Intact function of working memory (WM) is essential for children and adults to cope with every day life. Children with deficits in WM mechanisms have learning difficulties that are often accompanied by behavioral problems. The neural processes subserving WM, and brain structures underlying this system, continue to develop during childhood till adolescence and young adulthood. With functional magnetic resonance imaging (fMRI) it is possible to investigate the organization and development of WM. The present thesis aimed to investigate, using behavioral and neuroimaging methods, whether mnemonic processing of spatial and nonspatial visual information is segregated in the developing and mature human brain. A further aim in this research was to investigate the organization and development of audiospatial and visuospatial information processing in WM. The behavioral results showed that spatial and nonspatial visual WM processing is segregated in the adult brain. The fMRI result in children suggested that memory load related processing of spatial and nonspatial visual information engages common cortical networks, whereas selective attention to either type of stimuli recruits partially segregated areas in the frontal, parietal and occipital cortices. Deactivation mechanisms that are important in the performance of WM tasks in adults are already operational in healthy school-aged children. Electrophysiological evidence suggested segregated mnemonic processing of visual and auditory location information. The results of the development of audiospatial and visuospatial WM demonstrate that WM performance improves with age, suggesting functional maturation of underlying cognitive processes and brain areas. The development of the performance of spatial WM tasks follows a different time course in boys and girls indicating a larger degree of immaturity in the male than female WM systems. Furthermore, the differences in mastering auditory and visual WM tasks may indicate that visual WM reaches functional maturity earlier than the corresponding auditory system. Spatial WM deficits may underlie some learning difficulties and behavioral problems related to impulsivity, difficulties in concentration, and hyperactivity. Alternatively, anxiety or depressive symptoms may affect WM function and the ability to concentrate, being thus the primary cause of poor academic achievement in children.

Shwachman-Diamond syndrome : Clinical, genetic and radiological study

Shwachman-Diamond syndrome (SDS) is a rare autosomal recessive disorder in which the cardinal symptoms arise from exocrine pancreatic insufficiency and bone marrow dysfunction. Previous studies have suggested increased risk of fatal complications among Finnish SDS infants. The genetic defect responsible for the disease was recently identified; the SBDS gene is located at chromosome 7q11 and encodes a protein that is involved in ribosome biosynthesis. The discovery of the SBDS gene has opened new insights into the pathogenesis of this multi-organ disease. This study aimed to assess phenotypic and genotypic features of Finnish patients with SDS. Seventeen Finnish patients with a clinical diagnosis of SDS were included in the study cohort. Extensive clinical, biochemical and imaging assessments were performed to elucidate the phenotypic features, and the findings were correlated with the SBDS genotype. Imaging studies included abdominal magnetic reso-nance imaging (MRI), brain MRI, cardiac echocardiography including tissue Doppler examination, and cardiac MRI. The skeletal phenotype was assessed by dual-energy X-ray absorptiometry and bone histomorphometry. Twelve patients had mutations in the SBDS gene. In MRI, a characteristic pattern of fat-replaced pancreas with occasional enhancement of scattered parenchymal foci and of pancreatic duct was noted in the SBDS mutation-positive patients while the mutation-negative patients did not have pancreatic fat accumulation. The patients with SBDS mutations had significantly reduced bone mineral density associated with low-energy peripheral fractures and vertebral compression fractures. Bone histomorphometry confirmed low-turnover osteoporosis. The patients with SBDS mutations had learning difficulties and smaller head size and brain volume than control subjects. Corpus callosum, cerebellar vermis, and pos-terior fossa structures were significantly smaller in SDS patients than in controls. Patients with SDS did not have evidence of clinical heart disease or myocardial fibrosis. However, subtle diastolic changes in the right ventricle and exercise-induced changes in the left ventricle contractile reserve were observed. This study expanded the phenotypic features of SDS to include primary low-turnover osteoporosis and structural alterations in the brain. Pancreatic MRI showed characteristic changes in the SBDS mutation-positive patients while these were absent in the mutation-negative patients, suggesting that MRI can be used to differentiate patients harbouring SBDS mutations from those without mutations. No evidence for clinical cardiac manifestations was found, but imaging studies revealed slightly altered myocardial function that may have clinical implications. These findings confirm the pleiotropic nature of SDS and underscore the importance of careful multidisciplinary follow-up of the affected individuals.

Sikiöaikana päihteille altistuneiden lasten kasvuympäristö ja kehitys

Life of children exposed to alcohol or drugs in utero This study focused on the growth environment, physical development and socio-emotional development of children, aged 16 and under, who had been exposed to alcohol (n=78) or drugs (n=15) in utero. The aim of the study was to obtain a comprehensive picture of the living conditions of these children and to examine the role of the growth environment in their development. The study was carried out using questionnaires, written life stories and interviews. Attachment theory was used as a background theory in the study. Over half of the children exposed to alcohol were diagnosed with foetal alcohol syndrome (FAS), one quarter was diagnosed with foetal alcohol effects (FAE), and one fifth had no diagnosis. Most of the children exposed to drugs had been exposed to either amphetamines or cannabis, and a smaller number to heroin. Some of the children exposed to alcohol were mentally handicapped or intellectually impaired. The children exposed to drugs did not exhibit any serious learning difficulties but a considerable number of them had socio-emotional development problems. Language and speech problems and attention, concentration and social interaction problems were typical among both the children exposed to alcohol and those exposed to drugs. Only one child had been placed into long-term foster care in a family immediately after leaving the maternity hospital. In biological families there had been neglect, violence, mental health problems, crime and unemployment, and many parents were already dead. Two of the children had been sexually abused and four were suspected of having been abused. From the point of view of the children's development, the three most critical issues were 1) the range of illnesses and handicaps that had impaired their functional capacity as a result of their prenatal exposure to alcohol, 2) child's age at the time of placement on a long-term basis, and 3) the number of their traumatic experiences. The relationship with their biological parents after placement also played a role. Children with symptoms were found in all diagnosis categories and types of exposure. Children with the smallest number of symptoms were found among those who had never lived with their biological parents. Almost all children were exhibiting strong symptoms at the time of placement in foster care. In most cases, they were behaving in a disorderly manner towards others, but some children were withdrawn. The most conspicuous feature among those with the most severe symptoms was their disorganized behaviour. Placement in a foster family enhanced the children's development, but did not solve the problems. The foster parents who brought these children up did not receive as much therapy for the children and support for the upbringing as they appear to have needed. In Finland, transfer to long-term custody is based on strict criteria. The rights of children prescribed in the child protection law are not fulfilled in practice. Key words: FASD, FAS, FAE, alcohol exposure, drugs exposure, illegal drugs, early interaction, child development, attachment

Auditory - Visual Matching in Learning Disabilities : Intervention Studies from Finland and Sweden

The present thesis discusses relevant issues in education: 1) learning disabilities including the role of comorbidity in LDs, and 2) the use of research-based interventions. This thesis consists of a series of four studies (three articles), which deepens the knowledge of the field of special education. Intervention studies (N=242) aimed to examine whether training using a nonverbal auditory-visual matching computer program had a remedial effect in different learning disabilities, such as developmental dyslexia, Attention Deficit Disorder (ADD) and Specific Language Impairment (SLI). These studies were conducted in both Finland and Sweden. The intervention’s non-verbal character made an international perspective possible. The results of the intervention studies confirmed, that the auditory-visual matching computer program, called Audilex had positive intervention effects. In Study I of children with developmental dyslexia there were also improvements in reading skills, specifically in reading nonsense words and reading speed. These improvements in tasks, which are thought to rely on phonological processing, suggest that such reading difficulties in dyslexia may stem in part from more basic perceptual difficulties, including those required to manage the visual and auditory components of the decoding task. In Study II the intervention had a positive effect on children with dyslexia; older students with dyslexia and surprisingly, students with ADD also benefited from this intervention. In conclusion, the role of comorbidity was apparent. An intervention effect was evident also in students’ school behavior. Study III showed that children with SLI experience difficulties very similar to those of children with dyslexia in auditory-visual matching. Children with language-based learning disabilities, such as dyslexia and SLI benefited from the auditory-visual matching intervention. Also comorbidity was evident among these children; in addition to formal diagnoses, comorbidity was explored with an assessment inventory, which was developed for this thesis. Interestingly, an overview of the data of this thesis shows positive intervention effects in all studies despite learning disability, language, gender or age. These findings have been described by a concept inter-modal transpose. Self-evidently these issues need further studies. In learning disabilities the aim in the future will also be to identify individuals at risk rather than by deficit; this aim can be achieved by using research-based interventions, intensified support in general education and inclusive special education. Keywords: learning disabilities, developmental dyslexia, attention deficit disorder, specific language impairment, language-based learning disabilities, comorbidity, auditory-visual matching, research-based interventions, inter-modal transpose