Gabriele Heister

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.

Spatial Coding and Spatio-Anatomical Mapping: Evidence for a Hierarchical Model of Spatial Stimulus-Response Compatibility

Publisher Summary This chapter examines evidence for a hierarchical model of spatial stimulus-response (S-R) compatibility. S-R compatibility usually denotes the reaction-time advantage for spatially compatible S-R pairings over incompatible pairings in choice-reaction tasks. The spatial S-R compatibility is related to the compatibility between perceived stimulus position and the position of the response key. In most designs, the apparent and actual stimulus positions, as well as the positions of the responding hands and response keys, are the same. It is found that with respect to the stage of cognitive processing in which S-R compatibility effects are generated, the major position is that the response-selection stage, rather than the stimulus-encoding stage, is relevant. The results again suggest the prevalence of the spatial coding factor in S-R compatibility, because the compatibility effect for fingers depends on the relative spatial positions of the responding fingers with respect to each other and not on their anatomical relation. The small hand-compatibility effect for the condition with the responding hand being fixed throughout an experimental session can be explained by a modified attentional hypothesis.

Spatial S-R compatibility effects with unimanual two-finger choice reactions for prone and supine hand positions

The influence of spatial stimulus-response (S-R) compatibility on unimanual two-finger choice reactions was investigated. Subjects had to react as fast as possible to a flash of light that was presented in the right or left visual field. They used the index or middle fingers of their left or right hands to press the spatially same (compatible) key or the spatially different (incompatible) key. In Condition 1 the subjects’ palms faced down (pronation); in Condition 2 their palms faced up (supination) so that the spatial order of the fingers was reversed. A strong compatibility effect between right and left field of stimulation and spatially right and left finger was found under both conditions. Compatible reaction times were shorter than incompatible reaction times by 52 msec in the palm-down condition and by 61 msec in the palm-up condition. The results are interpreted as supporting the coding hypothesis of spatial compatibility.

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.

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.

Trail Making Test and visual search

SummaryThe performance in the Trail Making Test (Form A) was correlated with a variety of verbal and nonverbal tests in 5 groups of patients: Brocas aphasies (N= 18), Wernickes 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.ZusammenfassungDer Trail Making Test (Form A) dient gewöhnlich der Diagnose des allgemeinen Schweregrads von Hirnschädigungen verschiedenster Lokalisation und Genese. Der Patient hat dabei 25 unregelmäßig über ein Blatt verteilte Kreise in numerisch angegebener Reihenfolge so schnell wie möglich durch Bleistiftstriche miteinander zu verbinden. Mittels Korrelationen wurde die Beziehung verschiedener verbaler wie nonverbaler Tests zur Testleistung im Trail Making Test bei fünf Patientengruppn untersucht: Broca-Aphasiker (N=18), Wernicke-Aphasiker (N=19) und Hirngeschädigte ohne Aphasie mit rechtshemisphärischen (N =20), linkshemisphärischen (N=17) oder diffusen (N=18) Läsionen. Zwei Tests, bei denen visuelle Suchleistungen gefordert waren, korrelierten mit dem Trail Making Test. Beim Test „Objekte Finden“, der die Suchleistung anhand wechselnder Suchobjekte prüft, ergaben sich Korrelationen bei allen Patientengruppen. Der „Hidden Patterns Test“, bei dem das Suchobjekt konstant bleibt, korrelierte nur bei nichtaphasischen Patientengruppen mit den Leistungen im Trail Making Test. Nach der vorliegenden Untersuchung scheinen visuelle Suchleistungen, insbesondere bei variablen Suchobjekten, weitgehend unabhängig von der Lokalisation der Hirnschädigung zu sein und eng mit den Leistungen im Trail Making Test zusammenzuhängen.

EVIDENCE FOR STIMULUS-RESPONSE COMPATIBILITY EFFECTS IN A DIVIDED VISUAL FIELD STUDY OF CEREBRAL LATERALIZATION *

Abstract The question addressed here was whether lateral asymmetry of processing might be influenced by response position, a factor which is usually considered irrelevant in divided visual field studies of cerebral lateralization. For this purpose a lexical decision task, which had previously been investigated with lateral unimanual two-finger choice reactions (Heister et al. 1983), was carried out under different manual and vocal response conditions so as to uncover possible S-R compatibility effects. In the first study, thirty-two subjects responded unimanually, with their responding hand held in a medial position. In the second study, twenty-four subjects responded vocally, i.e., in both cases the spatial (right/left) cues of the response position were eliminated. The reaction time advantage for compatible S-R pairings obtained with lateral hand position disappeared in the experiment with medial hand position, and the right-field superiority for vocal reactions was much smaller than the right-field superiority for right-hand reactions in the earlier lateral experiment. This indicates that an S-R compatibility effect contributed to the results of the earlier experiment. Thus, S-R compatibility can affect even unimanual reactions in lateralization studies.

SPATIAL S-R COMPATIBILITY UNDER HEAD TILT *

Abstract Spatial stimulus-response (S-R) compatibility was investigated for different head positions. Subjects reacted with their right or left hand to a light presented to the right or left of a fixation point, pressing the spatially compatible or the spatially incompatible response key. Responding hands were either held in normal right or left position or were crossed. Three conditions of head posture were tested: Subjects responded (1) with upright head, (2) with the head tilted 90° to the right, and (3) tilted 90° to the left. Results showed a spatial compatibility effect for the upright-head condition. In the tilted-head conditions the spatial compatibility effect significantly decreased from the uncrossed-hands to the crossed-hands condition but did not shift to the opposite. These findings are discussed in relation to Ladavas and Moscovitchs (1984) results and interpreted with respect to a hierarchical model of spatial S-R compatibility.

S-R compatibility effect or cerebral laterality effect? Comments on a controversy.

This article investigates the role played by misleading terminology in the origins of a recent controversy about the nature of stimulus-response compatibility effects.