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Biomedical subjects

F Simion

Publications and source records attributed to F Simion.

13 recordsLinked to original sources
PubMed1982

Can an analytic/holistic dichotomy explain hemispheric asymmetries?

Same RTs to pairs of letters or other patterns are often faster than different RTs. This finding has led to hypothesize a two-process system of comparison: a fast holistic process for same and a slower analytic process for different responses. In connection with hemispheric specialization, RH has been characterized as a holistic and LH as an analytic processor. Therefore same responses should be mediated by RH and different responses by LH. In the present study, subjects made same-different judgments in the two visual fields to successively presented pairs of letters where degree of difference was systematically varied. RTs decreased with increases in the degree of difference in different responses. Same responses were faster than different. These results suggest analytic processing of different and holistic processing of same pairs. Since no clear-cut visual field superiority was found, the conclusion is that both hemispheres can process visual information analytically and holistically.

Adult↗
PubMed1980

Laterality effects, levels of processing, and stimulus properties.

Two hypotheses of hemispheric specialization are discussed. The first stresses the importance of the kind of processing to which the stimulus is subjected, and the second stresses the importance of the nature of the stimulus. To test these hypotheses, four experiments were carried out. In Experiment 1 verbal material was employed in a same-different classification task, and an overall right visual field superiority was found. Experiment 2, in which verbal stimuli were subjected to visuospatial transformations (i.e. mental rotations), yielded no laterality effect. In Experiment 3 geometrical figures were employed in a classification task similar to that of Experiment 1, and an overall left visual field superiority was found. In Experiment 4 both verbal and geometric stimuli were employed. The results showed a significant interaction between field of presentation and nature of the stimulus and no interaction between field of presentation and level of processing.

Discrimination Learning↗
PubMed1980

Sex-related differences in hemispheric asymmetries in processing simple geomerical figures.

16 (8 men, 8 women) subjects were required to respond same or different to pairs of geometrical figures. Same responses were given to physical identity pairs, to analog identity pairs, and to name identity pairs. Male subjects showed a left visual-field advantage regardless of the level of processing, whereas female subjects did not show a clear-cut hemispheric asymmetry. These results were discussed in terms of different processing strategies employed by the two sexes.

Dominance, Cerebral↗
PubMed1979

Evidence for a right hemisphere superiority and for a serial search strategy in a dot detection task.

In Experiment I the subjects manually signaled whether a solid dot was present or not in an array of empty dots presented either in the right or in the left visual field. The dots were either three or six and the target could appear in any of the possible locations. The results showed (a) a left visual field superiority; (b) a left hand superiority; (c) faster responses to three-dot than to six-dot displays, and (d) an effect of the location of the target in the display. Experiment II exactly replicated the previous experiment with the exception that the stimuli were centrally projected. The results showed: (a) a left hand superiority; (b) an effect of the number of dots in the display. These results can be interpreted to indicate: (a) a right hemisphere specialization in a simple feature detection task without any spatial component; (b) the compatibility of a right-hemisphere advantage with a serial search strategy.

Adult↗
PubMed1978

Different levels in processing simple geometrical figures.

An experiment has been conducted in order to extend to geometrical figures Posner's (1969) findings of various levels of processing for alphabetical material. Pairs of simple figures (triangles and trapezoids) were tachistoscopically presented to subjects asked to judge if they were "same" or "different". Subjects were instructed to respond "same" either if the two figures had the same shape or the same name, e.g., a scalene triangle paired with a right-angled one. The results support the theory of different levels of processing also for geometrical figures.

Adult↗
PubMedDate not supplied

[Influence of the delivery on neonatal competence].

It is a widely held view that the NBAS (Brazelton, 1973) can index differences in the level of the neurobehavioural organization of both pathological and normal newborns. The present study employed the NBAS to determine whether the type of delivery, i.e. cesarean or spontaneous vaginal, can influence the level of neurobehavioural organization in the first days of life. To this aim, two groups of healthy newborns, as assessed through obstetrical anamnesis and the Apgar index, were compared at 4, 24, 72 hours of postnatal life. Ten newborns were born by cesarean section and 10 were born by spontaneous vaginal delivery. The results did not show any neurobehavioural differences for the five clusters of the NBAS: Response decrement, Orientation, Motor, Range and Regulation of states. This outcome fails to support the hypothesis that the level of neurobehavioural organization in the first hours of postnatal life depends on the type of delivery. It must be considered, however, that the null results could be attributed to the way the NBAS is administered according to Brazelton's criteria of "best performance" and "flexibility of the examiner". In essence, these criteria require the NBAS to be administered several times in succession, by varying the order of clusters and the order of items within a cluster, until the "best performance" is obtained. Therefore, a second experiment was conducted, in which the criticisms and suggestions put forward by Prechtl (1982) were taken into account. Two groups of 10 newborns each, selected as before, were tested.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

[Modalities of adaptation to extrauterine environment of newborn infants during sleep].

Three groups of healthy full term neonates, differing in delivery modalities (elective caesarean section, labor of greater than or less than 7 hours) were investigated during sleep to evaluate postnatal adaptation. Adaptation modalities were assessed by NBAS, using the cluster of the decrements. It was found that neonatal responses change during sleep in relation to delivery modalities and to type of stimuli applied.

Adaptation, Physiological↗