ABSTRACT
Subjects were trained to discriminate three figures presented in the left field of vision and three other figures presented in the right field of vision. In these conditions, the two hemispheres usually show identical learning to discriminate the sets of stimuli because the hemispheres in healthy humans can exchange information. In the present study, training was performed in conditions in which, during presentation of stimuli, the opposite visual hemifield was covered by a mask. After training, the recognition of all six figures was compared by presenting them to the left and right visual fields. Each hemisphere recognized figures presented to the cognate hemifield but completely or very nearly failed to recognize figures learned by the other hemisphere. The mask would thus appear to block (completely or partially) the transmission of information from one hemisphere to the other. Thus, it was possible to train the hemispheres separately to recognize different sets of images in healthy subjects.
Subject(s)
Discrimination Learning/physiology , Functional Laterality/physiology , Pattern Recognition, Visual/physiology , Perceptual Masking/physiology , Vision, Monocular/physiology , Humans , Reference Values , Visual FieldsSubject(s)
Visual Acuity , Visual Perception/physiology , Adolescent , Adult , Age Factors , Child , Child, Preschool , Discrimination, Psychological , Humans , Sensory ThresholdsABSTRACT
Impulse activity of the posterior hypothalamic neurons was investigated under conditions of thermoneutral environment and at thermal skin stimulation of unanesthetized rabbits. Different types of the activity were classified. The responses of neurons to thermal stimulation were followed by changes in the activity types. Statistical criteria of these reactions were demonstrated.
Subject(s)
Body Temperature Regulation , Hot Temperature , Hypothalamus, Posterior/physiology , Hypothalamus/physiology , Neurons/physiology , Algorithms , Animals , Membrane Potentials , Neurons/classification , Rabbits , TemperatureABSTRACT
Distribution of the intervals between spikes of 50 neurons in the posterior hypothalamus were studied in 17 unanesthetized rabbits. Three main types of the interspike-interval distribution were found in the thermoneutral zone: 1) unimodal, mode 2-4 ms; 2) unimodal, mode 16-512 ms; 3) bimodal, modes 2-10 ms and 64-512 ms (the posterior hypothalamus temperature was 39.1 +/- 0.02 degrees C). When the posterior hypothalamus temperature was increased or decreased (by 0.5-1.5 degrees C), changes in the initial interspike-interval distributions were observed in 11 neurons. The changes disappeared when the thermal stimuli were removed; 6 neurons (of 11) altered the mean firing rates too when the posterior hypothalamus temperature was changed.
Subject(s)
Body Temperature , Hypothalamus, Posterior/physiology , Hypothalamus/physiology , Animals , Brain Mapping , Hypothalamus, Posterior/cytology , Neurons/physiology , Rabbits , Time FactorsABSTRACT
The subjects learned to recognize three figures presented in the left visual hemifield and three figures presented in the right visual hemifield. During presentation of a stimulus, the contralateral hemifield was overlapped by a mask. After the training, recognition of all six figures presented in the right and left visual hemifields, was compared. Each hemisphere recognizes figures which were learned in the corresponding visual hemifield, but the recognition of figures learned in the opposite visual hemifield was poor. Thus, the ability of the hemispheres to act separately in recognizing different sets of visual images, was established.
Subject(s)
Dominance, Cerebral , Form Perception , Pattern Recognition, Visual , Visual Fields , Visual Perception , Functional Laterality , Humans , LearningABSTRACT
In children of the first month of life, the formation of normal intestinal microflora was studied depending on whether they stayed with mothers or alone in the maternity home. Thirty healthy neonates born to young healthy mothers with a history of a favourable course of pregnancy which progressed to the delivery via the natural maternal passages were examined. Intestinal microbiocenosis in the newborn turned out more physiological provided they were placed at the "mother-child" department as compared to that when the newborn stayed alone. Organization of the joint staying of mothers and children in the wards of the maternity home increases the colonization resistance of the newborn, favours normal adaptation and may be one of the factors bringing about the diminution of the rate of pyoseptic diseases in the newborn.