Finger localization and finger praxis

The relations between finger localization and various types of finger praxis were assessed by estimates of the inter-correlations among the performance of 100 six-year-old children. Finger localization was related significantly to those types of finger praxis which involve movements of the individual fingers with respect to each other. Right-left discrimination was related to finger localization, but not to the measures of finger praxis.

The findings are interpreted in terms of the construct of the finger schema, which can be viewed as a determinant of performance in both the localization and praxis tasks. This construct can also serve as an explanation of the observed concurrence of finger agnosia and finger apraxia as a consequence of cerebral disease.     

Error Analysis of Limb and Orofacial Praxis in Children with Developmental Motor Deficits

Two models have been suggested to depict the relationship between disorders of limb and orofacial praxis. The first views apraxia as a unitary disorder in which the underlying mechanisms for each type are similar, while the second model suggests that there are two separate praxis systems: one for planning and controlling limb gestures and a second one for planning and controlling orofacial movements. The purpose of this study was to investigate whether a common mechanism may underlie deficits in limb and orofacial praxis in children. This was done by analyzing the types of praxis errors demonstrated by children with developmental motor deficits and normal controls when performing limb and orofacial gestures. Results indicated that there was consistency across modalities (i.e., limb, orofacial) in the types of praxis errors made by children with motor deficits, providing support for the idea that a common mechanism may underlie disruptions to limb and orofacial praxis in children. This study also examined developmental trends in gestural representation and in types of praxis errors. The findings revealed a striking developmental maturation in gestural ability between the ages of 6 and 11 years for all children. However, over this age range, children with developmental motor deficits were impaired relative to normal controls.     

Cerebral lateralization for speech in deaf and normal children

The cerebral lateralization pattern for speech production in normal hearing and congenitally deaf children was studied using the dual-task paradigm. Performance under the verbal task conditions showed predicted left hemispheric dominance for speech production in the normal hearing children. No developmental trends in asymmetry were found, suggesting that speech lateralization is present in normal 3-year-old children. These data support the developmental invariance hypothesis of cerebral organization. Deaf children showed more symmetrical patterns of cerebral control for speech production. No developmental trends in functional brain organization were observed among prepubescent deaf children.     

Behavior problems in children with pure speech disorders and in children with combined speech and language disorders

Forty-six children with pure speech disorders and 53 children with disorders of both speech and language were rated by parents and teachers for behavioral problems. Both parents and teachers rated the speech- and language-disordered children as having more severe and more frequent behavioral abnormalities,particularly hyperactive behaviors and developmental problems. Somatic complaints were more pronounced in the pure speech group. Conduct disorders,emotional problems, and poor relationships did not distinguish between the two groups. The importance of these findings for speech therapists and individuals working with speech- or language-impaired children is discussed.     

A practical method for screening psychiatric disorder in children with speech and language disorders

Children with speech and language disorders have been found to have a prevalence rate of psychiatric disorder of 50%. The authors sought to develop an efficient screening procedure to distinguish such children who have psychiatric disorder and those who do not. Cutoff scores for easily administered parent and teacher behavior rating questionnaires were investigated in a population of 256 children with speech and language disorders and known presence or absence of psychiatric disorder. It was learned that when the questionnaires are used together, a cutoff score of 31 or greater on either questionnaire has a positive predictive value of 74.1 % and a negative predictive value of 76.1%. This screening method shows promise in assisting speech pathologists in comprehensive evaluation and treatment planning for children with speech and language disorders.     

Immune disorders and handedness in dyslexic boys and their relatives

Thirty dyslexic and 30 control boys aged 7–11 years were compared for frequency of immune disorders and handedness as well as for family history of immune disorders and learning disabilities (dyslexia and stuttering). They were also compared for neurological status and for history of speech and language difficulties. There were no significant differences between the two groups in the frequency of immune disorders and in handedness. The results showed significantly more dyslexic boys with soft neurological signs and signs of speech and language disorders. The frequency of dyslexia was significantly higher in the relatives of the dyslexic boys. Also significantly more mothers of the dyslexic boys reported difficulties during pregnancy and complications at delivery. The results are discussed in terms of Geschwind's hypothesis and neuromaturational delay as possible determinants of developmental dyslexia.     

Apractic agraphia in a patient with normal praxis

Most right-handed crossed aphasics are not apractic. They usually have agraphia characterized by misspellings but retain the ability to write well-formed graphemes. We describe a right-handed patient with a right parietal lesion who was aphasic and not apractic. He was unable to write any formed graphemes despite a relatively preserved ability to spell aloud. We postulate that praxis and writing are dissociated in this patient because the motor engrams for praxis were located in his left hemisphere and the engrams for writing were in his right hemisphere. In addition, he comprehended commands for limb motor activities (praxis) far better than he comprehended other speech. This suggests that in this patient the areas used to comprehend limb motor commands may be anatomically distinct from areas important in comprehending other aspects of speech.     

Anomalous dominance in sibling stutterers: Evidence from CT scan asymmetries, dichotic listening, neuropsychological testing, and handedness

Two left-handed siblings with developmental stuttering are comprehensively described. The methods of study included speech and language evaluation, neurological and neuropsychological examinations, dichotic listening, auditory evoked responses, electroencephalogram, and CT scan asymmetry measurements. The data from each sibling showed evidence of anomalous cerebral dominance on many of the variables investigated. The CT scan measurements showed atypical asymmetries, especially in the occipital regions. These findings support the theory that stuttering may be related to anomalous cerebral dominance, both on functional as well as structural bases. Implications of anomalous dominance and the resultant effect of hemispheric rivalry on speech fluency are discussed.     

Are there different patterns of cerebral asymmetry between dyslexic subtypes?

The purpose of this research has been to analyze the cerebral asymmetry in dyslexic children and, specifically for demonstrating whether there are different patterns of cerebral asymmetry among subtypes of dyslexia. We used a sample of 89 dyslexic children divided into subtypes obtained from the Jimenez and Ramirez (2002) study. The dual-task method was used to assess hemispheric specialization. The data were compared with that obtained from a control group of normal readers of same age (CA; N= 37) and with a younger reading level control group (RL; N= 40). We found that in the dyslexic group, similarly to the younger reading level group, a high percentage of children showed convergence in the left hemisphere of both linguistic and spatial functions. This pattern was also found in the RL control group. On the other hand, we did not find different patterns of cerebral asymmetry between dyslexic subtypes.     

Verbal-manual time sharing in children as a function of task priority

Eighty-three normal, right-handed children performed (a) unimanual finger tapping, (b) recitation of a tongue twister, and (c) both tasks concurrently. Tradeoffs in dual-task performance were measured as the priority assigned to each task was manipulated. Irrespective of task priority, speaking interfered to a greater degree with right-hand tapping than with left-hand tapping, but the effect of tapping upon verbal production and speech errors was not lateralized. The asymmetric effect of speech upon tapping, which was seen in 85.5% of the children, cannot be attributed to the disparity between hands in baseline tapping rate. The findings suggest that time-sharing asymmetry reflects cerebral lateralization of speech, but only some of the results would be predicted on the basis of a functional distance principle of cerebral organization.     

Comparison of motor praxis and performance in children with varying levels of developmental coordination disorder

The praxis test is a less well-documented method to determine functional manifestations of childhood dyspraxia. For this study, children aged 6–8 years were recruited as follows: 17 children with DCD, 18 at risk of DCD and 35 without obvious problems in motor coordination. The Movement Assessment Battery for Children (MABC-2) was used to measure motor performance and identify the motor incoordination. This study developed a battery of tests to assess limb praxis using a praxis imagery questionnaire, gesture representation, and questions about knowledge of object use. In the comparison of subtests within the praxis test, significant differences were observed across groups on the praxis imagery questionnaire and gesture representation tests but not on knowledge of object use. Similar results were observed in the correlation analyses, in which a weak relationship between MABC-2 and praxis tests was observed. The DCD group had lower scores on the praxis imagery questionnaire, whereas the group at risk of DCD had lower scores on most gesture production tests. Our study provides a better understanding of the nature of the childhood dyspraxia and sheds light on its effect on motor coordination to identify praxis tests with specific clinical meanings in children with movement disorders.     

Right-hemisphere speech representation and comprehension of syntax after left cerebral injury

Comprehension of language and visuo-spatial abilities were studied in 12 surgical patients with left cerebral lesions and right-hemisphere speech representation verified by sodium amobarbital tests. When left-hemisphere symptoms preceded the acquisition of speech, impaired understanding of syntactically complex sentences was associated with an early, but not late, onset of convulsive seizures. Other behavioral measures did not show a similar effect of age at seizure onset. Sparing or loss of comprehension could not be related to any aspects of the neurological histories in cases with right-hemisphere speech acquired before the onset of left-hemisphere symptoms. Factors which may have influenced the development of right-hemisphere language comprehension are discussed.     

Spontaneous private speech and performance on a delayed match-to-sample task

Spontaneous private speech samples were obtained from 65 kindergarten children (mean age 70.3 months) from one suburban (n = 36) and one city (n = 29) school as they worked alone on a delayed match-to-sample (DMS) task with three levels of difficulty (2, 10, and 30 sec delays). As expected increases in DMS delay intervals produced decreased performance and increases in private speech. The expected increased positive relationship between task relevant private speech and performance for longer delays was found in city children but not suburban children. Since mean IQ scores were significantly different for the two groups this variable was further examined in post hoc analyses and discussed along with socio-economic status as possible explanations for the observed school-sample differences. A within-subject comparison for all children showed the percentage of speaking trials correct at 30-sec delay to be significantly greater than the percentage of nonspeaking trials correct. The effect of one experimenter modeled trial on a subsequent 10 trials at 30-sec delay was to increase speech and performance and to show a stronger relationship between speech and performance than for premodeling trials. These exploratory findings with a relatively simple two color matching task suggest further explorations of spontaneous private speech as a way of studying internalization of self regulatory cognitive strategies.     

Psychiatric risk in children with speech and language disorders

Based on an initial community sample of 1,655 5-year-old children, this report utilized the risk statistic to estimate a child's risk for developing a psychiatric disturbance depending on his or her status as speech/language-impaired. Results showed that risk estimates varied as a function of gender and source of information (teacher, parent, psychiatric reports). Overall, speech- and language-impaired children had a higher risk for developing a psychiatric disturbance compared with normal language controls, with speech/language-impaired girls being at greater risk than boys.     

An examination of the interactions between mothers and children with anxiety disorders

This study examined the association between parenting styles and mother and child anxiety. Maternal overinvolvement and negativity/criticism were evaluated during a speech preparation task (N = 135 dyads) and a Five Minute Speech Sample (FMSS) from mothers (N = 155). During the speech task interaction, mothers of anxious children (aged 4–16 years), regardless of their own anxiety, were observed to be more overinvolved than mothers of nonanxious children. Similarly, the FMSS showed that mothers of anxious children (aged 4–17 years) were more overprotective, self-sacrificing, or nonobjective than mothers of nonanxious children, irrespective of maternal anxiety status. No differences in maternal negativity were found on the speech task between any of the groups. However, the FMSS showed that mothers of anxious children were more critical than mothers of nonanxious children, regardless of maternal anxiety status. These results support the relationship between overinvolved, critical parenting and child anxiety, but suggest that maternal anxiety is not associated with increased overinvolvement or criticism. Theoretical implications are discussed.     

Spoken and gestural production in a naming task by young children with Down syndrome

Lexical production in children with Down syndrome (DS) was investigated by examining spoken naming accuracy and the use of spontaneous gestures in a picture naming task. Fifteen children with DS (range 3.8-8.3 years) were compared to typically developing children (TD), matched for chronological age and developmental age (range 2.6-4.3 years). Relative to TD children, children with DS were less accurate in speech (producing a greater number of unintelligible answers), yet they produced more gestures overall and of these a significantly higher percentage of iconic gestures. Furthermore, the iconic gestures produced by children with DS accompanied by incorrect or no speech often expressed a concept similar to that of the target word, suggesting deeper conceptual knowledge relative to that expressed only in speech.     

Articulatory drift in the speech of children with articulation and phonological disorders

This study used electropalatography to identify articulatory drift in alveolar stops (/t/ and /d/) produced by 10 children with functional articulation and phonological disorders. Drift involves an abnormal change in place of articulation that occurs during stop closure. An index was used to measure drift, with higher values indicating greater drift. The results showed that drift was higher for children who produced undifferentiated gestures (articulations with increased tongue-palate contact). Drift is an important characteristic of articulation because it is believed to reflect impaired speech motor control. In addition, drift could explain some perceptually based speech errors that are frequently reported in functional disorders.     

Naming disorders and semantic representations

The status of semantic conceptual structures in aphasia was investigated with relation to naming disorders in spontaneous and constrained speech production. A battery of six tasks was administered to 25 control subjects and 25 aphasics: spontaneous speech production (from which the percentage of nouns was calculated), confrontation naming, understanding class relationships (verbal and pictorial), and understanding thematic relationships (verbal and pictorial). Results indicated the important role of taxonomic abilities for naming, while other conceptual structures (i.e., thematic relations) do not seem to play any important role in the process of naming. These results are discussed in terms of the internal organization of semantic information.This work was supported by grants to Drs. Semenza and Bisiacchi from the Ministero della Pubblica Istruzione and by the Consiglio Nazionale delle Ricerche Unita 14, Scienza del Comportamento.