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Biomedical subjects

G Heister

Publications and source records attributed to G Heister.

15 recordsLinked to original sources
PubMed1994

Spatial S-R compatibility: positional instruction vs. compatibility instruction.

Subjects had to perform both in a classical spatial compatibility experiment where they were instructed to press a right or left button to a right or left stimulus ('positional instruction'), and in a variant, where they had to give a spatially compatible or incompatible response depending on the color of the stimulus ('compatibility instruction'). The result shows the normal advantage of compatible over incompatible responses for the experiment with positional instruction whereas the spatial compatibility effect completely disappeared for the experiment with compatibility instruction. This supports a translation hypothesis and speaks against an automatic activation hypothesis of spatial stimulus-response compatibility.

Adult↗
PubMed1989

Shift of functional cerebral asymmetry during the menstrual cycle.

This study investigated whether for females, who are said to be less strongly lateralized for cognitive functions than men, hemispheric superiority might depend on the phase of the menstrual cycle. The results show that while asymmetry in lexical decisions did not change throughout the menstrual cycle, asymmetry in face perception decreased linearly from a large right hemisphere superiority during menstruation to a small left hemisphere superiority during the premenstrual phase. This is seen as being relevant not only for the discussion of sex differences in cerebral asymmetry but also for the concept of cerebral organization in general.

Adult↗
PubMed1989

Spatial S-R compatibility with orthogonal stimulus-response relationship.

Spatial stimulus-response (S-R) compatibility with unimanual two-finger choice reactions was investigated under conditions in which the spatial orientation of response keys was either parallel to or perpendicular to the orientation of the stimuli. Subjects responded to green or red lights in the left or right visual field (irrelevant stimulus location). The response keys were oriented horizontally on the left or right side of the body midline parallel to the stimuli, and were pressed with the palms facing down (Condition A), or were oriented orthogonally to the stimuli in the midsaggital plane, either horizontally and pressed with palms facing down (B) or facing up (C), or vertically and pressed with palms facing the body (D). The results for Condition A demonstrate the usual spatial S-R compatibility effect between field of stimulation and spatial position of responding finger. For Conditions B and D, a strong reaction time advantage still obtained for those stimulus-finger pairings that are compatible under Condition A. Condition C revealed an RT advantage for the opposite pairings. This shift of the compatibility effect from Condition B to Condition C indicates that the left/right distinction of fingers does not follow a simple, fixed spatio-anatomical mapping rule. The results are discussed within the framework of a hierarchical model of spatial S-R compatibility, with spatial coding and spatio-anatomical mapping as factors.

Adult↗
PubMed1984

Sex differences and cognitive/motor interference with visual half-field stimulation.

This study examines the possible influence of the response on the asymmetry of lexical decision in a visual half-field study and whether sex differences in asymmetry might be determined by response factors. The results support the importance of these factors: when response demands were increased (pressing the button three times instead of once) the reaction time asymmetry was reversed for male subjects.

Adult↗
PubMed1983

Sex differences and asymmetry of lexical processing: effects of responding hand, stimulus familiarity and intraexperimental experience.

The possibility that language processing functions are more nearly equally represented in the two hemispheres of women than of men was investigated tachistocsopically by means of a lexical decision task in which words and nonwords were controlled for familiarity, and exposed vertically in the left and right visual half-fields. Analysis of both unimanual reaction times and response accuracy revealed differences in asymmetry as well as differences between male and female subjects which tended to decrease as a function of intraexperimental experience. Theoretical and methodological problems associated with reaction time and response accuracy as measures of language lateralization are discussed.

Adult↗
PubMed1983

Visual half-field superiority for righthanders with familial sinistrality: sex differences and cognitive/motor interference in a lexical decision task.

By means of a lexical decision task in which words and nonwords were controlled for familiarity, the question whether sex and familial handedness influence right-field superiority for righthanded subjects was investigated. Analyses of unimanual reaction times and response accuracy revealed sex differences and a cognitive-motor interference for the male group. For hit rates the men, reacting with their right hands, showed a right-field superiority for words and a left-field superiority for meaningless syllables, and the men reacting with their left hands showed the reversed asymmetry. Theoretical problems associated with reaction time and hit rate asymmetry as indicators of language lateralisation are discussed.

Adult↗
PubMed1982

Trail Making Test and visual search.

The performance in the Trail Making Test (Form A) was correlated with a variety of verbal and nonverbal tests in 5 groups of patients: Broca's aphasics (N = 18), Wernicke's aphasics (N = 19) and nonaphasic patients with right hemisphere (N = 20), left hemisphere (N = 17) or diffuse (N = 18) lesions. Correlations with the Trail Making Test were found for two tests, both requiring visual search. The "Objects Finding Test" in which the target varies from item to item showed high correlations for all groups of patients. The "Hidden Patterns Test", in which the target is kept constant, correlated only on the groups of nonaphasic patients. It is concluded (1) that visual search, as tested here, is not restricted to lateralized cortical functions, and (2) that the performance in the Trail Making Test depends largely upon processes involved in visual search of varying targets.

Adult↗