The growth of stability: postural control from a development perspective

This study compared central nervous system organizational processes underlying balance in children of three age groups: 15-31 months, 4-6 years, and 7-10 years, using a movable platform capable of antero-posterior (A-P) displacements or dorsi-plantar flexing rotations of the ankle joint. A servo system capable of linking platform rotations to A-P sway angle allowed disruption of ankle joint inputs, to test the effects of incongruent sensory inputs on response patterns. Surface electromyography was used to quantify latency and response patterns. Surface electromyography was used to quantify latency and amplitude of the gastrocnemius, hamstrings, tibialis anterior, and quadriceps muscle responses. Cinematography provided biomechanical analysis of the sway motion. Results demonstrated that while directionally specific response synergies are present in children under the age of six, structured organization of the synergies is not yet fully developed since variability in timing and amplitude relationships between proximal and distal muscles is high. Transition from immature to mature response patterns was not linear but stage-like with greatest variability in the 4- to 6- year-old children. Results from balance tests under altered sensory conditions (eyes closed and/or ankle joint inputs altered) suggested that: (a) with development a shift in controlling inputs to posture from visual dependence to more adult-like dependence on a combination of ankle joint and visual inputs occurred in the 4- to 6-year-old, and reached adult form in the 7- to 10-year-old age group. It is proposed that the age 4-6 is a transition period in the development of posture control. At this time the nervous system (a) uses visual-vestibular inputs to fine tune ankle-joint proprioception in preparation for its increased importance in posture control and (b) fine tunes the structural organization of the postural synergies themselves.     

Reflex responses of human lip muscles to mechanical stimulation during speech

The role played by reflex pathways in the production of movement has been a significant issue for motor control theorists interested in a wide variety of motor behaviors. From studies of locomotion and chewing, it appears that gains in reflex pathways can be altered so that activity in these pathways does not produce destabilizing responses during movement. In speech production, recent experimental evidence has been interpreted to suggest that autogenetic lip reflexes (perioral reflexes) are suppressed during sustained phonation or speech production. The present study was conducted to assess the effects of phonation, direction of movement, and ongoing speech production on reflex responses of lip muscles. The present results suggest, in contrast to earlier work, that this reflex pathway is not suppressed or absent because the amplitude of the observed response depends upon the activation levels of the various muscles of the lower lip and, therefore, indirectly on the nature of the gesture the subject is instructed to produce.     

Flicker fusion frequency and organic syndrome in alcoholics

Flicker fusion frequencies of 48 healthy controls and of 35 alcoholics were measured to detect possible associations between flicker fusion and signs of nonspecific brain damage, the aim of the study. FFF was statistically significantly lower in patients addicted to alcohol than in healthy subjects. Lower flicker fusion frequencies were associated with the severeness of organic psychosis as rated psychopathologically. The hypothesis that addiction to alcohol is a sign of diffuse, nonspecific, organic brain damage was discussed.     

Antidepressant treatment of children: clinical relapse is unrelated to tricyclic plasma concentrations

Plasma concentrations of imipramine and amitriptyline and their desmethylated metabolites were measured in 20 children being treated for major depressive illness 2 wk. and 5 to 10 wk. after achieving drug dosages of 2.25 mg/kg body weight. At 2 wk. all children had exhibited clinical improvement, but by 10 wk. 4 of the 10 children treated with imipramine and 5 of the 10 children treated with amitriptyline had experienced clinical relapse of depressive symptoms. Tricyclic antidepressant plasma concentrations and ratios were comparable in the subgroups of children who maintained their clinical improvement and those who relapsed. There was no evidence of a systematic decline in plasma tricyclic antidepressant concentrations in those children who relapsed.     

Frequency of neurologic-psychiatric findings in the late phase following minor and medium severe blunt craniocerebral injuries

The authors present a short review of the pertinent literature and report on their own neuropsychiatric findings following internal craniocerebral injuries, at the same time drawing attention to the necessity of psychological examination. Statistical comparisons with the international literature are complicated owing to the different classifications used for craniocerebral injuries.     

Cognitive styles: illusory phenomena

The relationship between cognitive style and illusion magnitude was examined using the assimilation and contrast Delboeuf distortions. As in previous research, field dependence correlated positively with assimilation; however, a significant negative correlation with contrast was also found, suggesting that, while field dependence may involve the illusory integration of the stimulus field, field independence may involve its equally illusory differentiation.