Ethnic differences in alcohol sensitivity.

Japanese, Taiwanese, and Koreans, after drinking amounts of alcohol that have no detectable effect on Caucasoids, respond with a marked facial flushing and mild to moderate symptoms of intoxication. Group differences are present at birth, and are probably related to variations in autonomic reactivity.

The orphans of Eritrea: are orphanages part of the problem or part of the solution?

OBJECTIVE: This study compared the mental health and cognitive development of 9- to 12-year-old Eritrean war orphans living in two orphanages that differed qualitatively in patterns of staff interaction and styles of child care management. METHOD: The directors and several child care workers at each institution were asked to complete staff organization and child management questionnaires. The psychological state of 40 orphans at each institution was evaluated by comparing their behavioral symptoms and performance on cognitive measures. RESULTS: Orphans who lived in a setting where the entire staff participated in decisions affecting the children, and where the children were encouraged to become self-reliant through personal interactions with staff members, showed significantly fewer behavioral symptoms of emotional distress than orphans who lived in a setting where the director made decisions, daily routines were determined by explicit rules and schedules, and interactions between staff members and the children were impersonal. CONCLUSIONS: When orphanages are the only means of survival for war orphans, a group setting where the staff shares in the responsibilities of child management, is sensitive to the individuality of the children, and establishes stable personal ties with the children serves the emotional needs and psychological development of the orphans more effectively than a group setting that attempts to create a secure environment through an authoritative style of management with explicit rules and well-defined schedules.

The effects of infantile malnutrition on behavioral development: a follow-up study.

Thirty-one children and young adults who had been severely malnourished in infancy due to intestinal disease, were compared with sibling controls for psychometric intelligence, academic performance as judged by teacher ratings, and developmental history as judged by parental questionnaires. Older members of the sample were also examined on the Lincoln-Oseretzky Motor Development Scale and by a brief psychiatric interview. There were no significant differences between patients and controls on any outcome measure. Furthermore, previously malnourished individuals were performing at or above age equivalent norms on all psychological tests. The findings suggest that the adverse behavioral effects of severe infantile malnutrition observed in children below the age of 5 yr are, to a large extent, compensated during development when the children are raised in supportive home and school environments.

The dynamics of bimanual coordination in developmental dyslexia.

The temporal organization of symmetric and asymmetric bimanual coordination tasks was compared between dyslexic adults and normally reading controls by means of a dynamical systems research strategy. Both groups demonstrated the influence of the intrinsic dynamics of rhythmic motor behavior on the performance of asymmetric bimanual tasks. In normal readers, manual asymmetries of motor control had a significant effect on the relative phasing of finger movements; no such effects were observed in dyslexic subjects. Group differences are discussed in terms of the interaction between neurological constraints and dynamic principles of spontaneous pattern formation.

Impaired motor timing control in specific reading retardation.

The temporal organizations of unimanual and coordinated bimanual finger tapping was compared between adolescent normal and retarded readers of above average intelligence. The same subjects were examined for speech articulation during the timed repetition of single syllables and syllable sequences. Retarded readers had substantially greater difficulty on tasks of interlimb coordination than on unimanual tapping and substantially greater difficulty rapidly sequencing syllable strings than repeating single syllables. An experimental manipulation of movement speed for both tasks indicated that the threshold at which movement speed degrades timing precision for coordinated action best characterizes the motor impairment of retarded readers.

Early stages in the acquisition of a bimanual motor skill.

Children and adults were trained and tested on a coordinated bimanual task that required them to rotate both hands either at the same or at different angular velocities in order to move the pen of an X-Y recorder along three angles of slant (45, 67 and 22 degrees), and to rotate both hands in the same clockwise direction rather than as mirror image movements. Initially both groups exhibited a tendency to rotate both hands at the same angular velocity even when the task required differential motor output from the two hands. With visual feedback, the tendency toward synchronization, such that both hands moved at the same angular velocity, was asymmetrically distributed, but under blindfolded conditions such asymmetries disappeared. Accuracy of performance increased with practice; and visual feedback enhanced accuracy of performance. The findings suggest that during early stages in the acquisition of a bimanual skill, unintended bilateral coactivation occurs at multiple levels of motor organization; mirror associated movements are only one simple subset of unintentional intermanual synergies.

Sex differences and ethnic variations in speed of automatized naming.

White American-Caucasian children from 6-12 yr showed significant sex differences on four tasks of rapid automatized naming; and in each case, girls outperformed boys. American-Chinese, native Japanese and native Korean schoolchildren did not differ from American-Caucasians in naming speed when scores for boys and girls were combined. However, in the three Asian subgroups, there were no sex differences on any naming task. It is suggested that biological as well as experiential factors contribute to behavioral sex differences; and that biological (genetic) variables associated with mating group membership modify the expression of cognitive sex differences.

Family patterns of developmental dyslexia: clinical findings.

Two separate groups of dyslexia families were ascertained through probands attending special schools for dyslexic students. An additional control group of families was ascertained through randomly selected students attending public schools. The 3 groups were interviewed by questionnaire about the family's demographic characteristics, and about the incidence of reading and spelling disorders in all first and second order relatives. One group of dyslexia families was also examined by standardized intelligence and academic achievement tests. Developmental dyslexia was found to aggregate in families; there were 4-5 times as many affected males as females among clinically identified students attending the special schools, but the sex ratio of affected relatives after probands had been excluded was approximately 1.4 males for every female. Sibs were at greater risk for reading difficulties when one parent was affected than when neither parent was affected. Sibs were also at greater risk for academic difficulties, and affected sibs were more severely impaired, when the father rather than the mother was the affected parent. In dyslexia families with 2 affected parents, the sibs were at greater risk, and the affected sibs were more severely impaired, than in families where only one parent was affected. Moreover, in families with 2 affected parents, both of the parents were more severely impaired in reading and spelling than parents of the same sex in families with one affected parent. Some indirect evidence is presented that assortative mating may codetermine patterns of affectedness in dyslexia families.

Family patterns of developmental dyslexia. Part III: Spelling errors as behavioral phenotype.

The major trends in current research on developmental dyslexia assume that impaired phonological processing is the core deficit in this disorder. Our earlier studies indicated that half of all dyslexic persons have significant deficits of bimanual motor coordination, and that impaired temporal resolution in motor action may identify a vertically transmitted behavioral phenotype in familial dyslexia. This report examines the relationship between spelling errors as a measure of impaired phonological processing and motor coordination deficits in the same dyslexia families. Affected family members with motor coordination deficits made significantly more dysphonetic spelling errors than dyslexic family members without motor deficits, but there was no evidence that dysphonetic spelling is vertically transmitted in dyslexia families. On the other hand, affected offspring of affected parents with motor coordination deficits made relatively more dysphonetic spelling errors than the affected offspring of parents without motor coordination deficits. We suggest that dysphonetic spelling may be one outward expression of a vertically transmitted behavioral phenotype of impaired temporal resolution that is clearly expressed in coordinated motor action.

Variable expression of the fragile X syndrome in heterozygous females of normal intelligence.

The cognitive, linguistic and memory functions of non-retarded fragile X heterozygotes and matched controls were examined by a detailed protocol of neuropsychological measures in order to determine the incidence of specific learning disabilities in this subgroup, and to compare their performance profiles with those of control subjects (mothers of Down syndrome sons). There were no group differences in psychometric intelligence, but the heterozygotes scored significantly lower than controls on most academic achievement tests, as well as on language-based neuropsychological measures. By neuropsychological criteria, 8 of the 15 heterozygotes, but only one of the controls, exhibited performance profiles consistent with a diagnosis of specific learning disability, and similar to cognitive profiles commonly seen in individuals from the general population with developmental dyslexia.

Family patterns of developmental dyslexia, part II: behavioral phenotypes.

The motor control of bimanual coordination and motor speech was compared between first degree relatives from families with at least 2 dyslexic family members, and families where probands were the only affected family members. Half of affected relatives had motor coordination deficits; and they came from families in which probands also showed impaired motor coordination. By contrast, affected relatives without motor deficits came from dyslexia families where probands did not have motor deficits. Motor coordination deficits were more common and more severe among affected offspring in families where both parents were affected than among affected offspring in families where only one parent was affected. However, motor coordination deficits were also more common and more severe in affected parents when both parents were affected than among affected parents in families where only one parent was affected. We conclude that impaired temporal resolution in motor action identifies a behavioral phenotype in some subtypes of developmental dyslexia. The observed pattern of transmission for motor deficits and reading impairment in about half of dyslexia families was most congruent with a genetic model of dyslexia in which 2 codominant major genes cosegregate in dyslexia pedigrees where the proband is also motorically impaired.

Dual task performance during bimanual coordination.

Right-handed men and women tapped two mechanical keys in time to an entraining metronome, using each hand alone and the two hands in alternation. Concurrently, they recited familiar nursery rhymes or read unfamiliar text out loud. The direction of interference from the language-based tasks on manual performance was measured relative to baseline performance. Magnitude and direction of interference from both language tasks were greater during bimanual alternation than unimanual performance. However, the direction of interference during bimanual alternation differed significantly between right-handed men and women, and the sex differences in direction of interference differed according to the characteristics of the language-based secondary task. Right-handed subjects with a family history of sinistrality showed less overall and less lateralized dual task interference than right-handed persons without a family history of sinistrality.

Manual asymmetries of motor sequencing in boys with reading disability.

Boys with reading disability were asked to tap two mechanical keys in time to the beat of a metronome, with left and right hand alone, and with alternating hands. On the single hand trials these boys tapped as well as normal boys with both left and right hands, but when asked to alternate hands, their tapping stability, particularly of the left hand, deteriorated significantly and was worse than that of much younger normal boys. It is argued from evidence from patients with surgical commissurotomies that the motor deficiency in synchronizing left and right hands may be due to a disturbance in interhemishperic cooperation in the boys with reading disability, and it is suggested that the reading problems of these children may be the consequence of a developmental delay in interhemispheric cooperation.

Diminished motor timing control in children referred for diagnosis of learning problems.

Disabled readers exhibit motor timing control (MTC) deficits in bimanual coordination relative to average readers. This article evaluates to what extent poor MTC is specific to reading or if it is related to learning problems in general. Children (7 to 11 years of age) referred for learning impairment (LI; n = 100) and same-age children nonlearning impaired (NLI; n = 243) performed a paced finger-tapping task. Greater variability of interresponse intervals was associated with poorer reading, spelling, and arithmetic achievement. The LI group performed more poorly than the NLI group, a difference that persisted even after adjusting for reading skill. Poor MTC is associated with poor reading but may also be a characteristic of children referred for learning problems, possibly signaling increased vulnerability of underlying neural integrative processes relevant to the child's adaptation to academic demands, including reading.

The Solomuna Orphanage: a historical survey.

The social-emotional status and behavioral symptoms of Eritrean war orphans were compared before and after a major social reorganization of the institution had been implemented. The comparison was based on direct clinical observations and behavior checklist questionnaires. Two years after the orphanage was restructured, the emotional state of the orphans had improved dramatically. The findings suggest that even when financial and technical resources are severely limited, it is possible to provide humane group care for severely traumatized orphans by applying basic clinical principles of child development.

Patterns of breath intervals during non-nutritive sucking in full-term and 'at risk' preterm infants with normal neurological examinations.

The interaction between respiration and non-nutritive sucking rhythms was investigated in 12 sleeping, normal full-term, newborn infants and in 14 preterm infants were were examined repeatedly at 34, 40 and 46 wk of conceptional age. Full-term infants showed a shortening of breath intervals in the middle of sucking bursts and a lengthening of the breath interval spanning the end of sucking bursts. The differences were more marked in females than males. A rhythm interaction between sucking and respiration was also observed in preterm infants as young as 34 wk of conceptional age. Clinical neurological examinations did not discriminate between preterm infants above and below a median score for optimal obstetric conditions, but the interaction between breathing and sucking rhythms made such discrimination, most clearly in females. Preterm infants with lower optimal obstetric scores showed less change of breath durations during sucking than preterms with higher scores. It was concluded that interaction of concurrent motor rhythms may be a sensitive index of central nervous system integrity in newborn infants, even when there are no clinical neurological signs of nervous system dysfunction.

Rate variables and automatized naming in developmental dyslexia.

The rate variable in rapid automatized naming (RAN) was investigated in 50 adolescent and 40 adult students with developmental dyslexia, in matched normal controls, and in learning-disabled students without reading difficulties. Visual stimuli depicting familiar colors and common objects were presented in isolation at three film speeds and three exposure times. Film speed and exposure time contributed as independent variables to error rate; and dyslexic subjects of both age groups made significantly more naming errors than controls. Dyslexic subjects also responded with longer naming latencies than controls when the same RAN stimuli were presented in a continuous sequential mode as a matrix of rows and columns. Naming latencies in the sequential presentation were highly correlated with naming errors in the film version. The implications of reduced naming rates for nongraphological stimuli in developmental dyslexia are discussed.

Rapid automatized naming in children referred for evaluation of heterogeneous learning problems: how specific are naming speed deficits to reading disability?

Because the Rapid Automatized Naming (RAN) test reliably predicts reading skill, it is typically viewed as a diagnostic indicator of risk for reading disability (RD). Since most of the work on naming speed has been undertaken within the framework of reading research, however, the extent to which poor RAN is specifically associated with RD or with learning impairment (LI) in general is uncertain. We tested the hypothesis that slow naming speed is specific to RD. Participants were 188 children (ages 7 to 11) referred for evaluation of learning problems. Receiver operating characteristic (ROC) analysis was used to evaluate the utility of the RAN task for classifying children in diagnostic groups. RAN was an excellent tool for detecting risk for learning problems in general, but it was much less effective at distinguishing LI children with and without RD from each other.

The greeting behavior of fragile X males.

Mentally retarded males with a fragile site on the X chromosome (Xq27) were observed to exhibit a highly idiosyncratic but well-coordinated, stereotypic form of gaze avoidance during greeting ceremonies that involved the whole upper body. A comparison group of persons with other etiologically defined syndromes of mental retardation did not. Results suggest that the aberrant greeting behavior may be uniquely associated with one syndrome of mental retardation with a defined genetic etiology. The behavior pattern does not appear until middle childhood, however, and its developmental induction remains to be explained.

A functional analysis of human mirror movements.

In this report, an experimental method for investigating the effect of variations in force, amplitude, and frequency of oscillations of the isometric pincer grasp on mirror movements (MM) is described. Normal adults (N = 24) were used as experimental subjects. The magnitude of MM was greater at relatively high static force levels maintained by the passive hand (26% of maximum volitional force or MVF) than at low force levels (4% MVF) in the passive hand. By contrast, the magnitude of MM was smaller at relatively large (20.5% MVF) than at small (9.5% MVF) mean force levels of the active hand when the static force in the passive hand as well as the amplitude and range of oscillation frequencies of the active hand were held constant. The magnitude of MM relative to active hand oscillation was smaller when the active hand oscillated around a relatively large amplitude (22% of MVF) than when it did so around a small amplitude (8% of MVF) at constant mean force levels and oscillation frequencies. The absolute magnitude of MM was not affected by this change in oscillation amplitude. In all experiments, the magnitude of MM was consistently less at relatively high than at low frequencies of oscillation in the active hand. Intrinsic variables of motor control have a major effect on the inducation and modulation of MM, and their contribution may be as great as that of subject variables. The present results differed substantially from those of others who have used similar experimental paradigms. The major difference was the direction of change in power transfer from the active to the passive hand with changes of force in the active hand. Possible reasons for these differences are discussed.