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Biomedical subjects

P Bakan

Publications and source records attributed to P Bakan.

At least 19 recordsLinked to original sources
PubMed1999

Eye tracking in normals: spem asymmetries and association with schizotypy.

SPEM was recorded electro-oculographically during visual tracking of sinusoidal targets oscillating at .4 and .8 cycles per second in one hundred nineteen undergraduates. The logarithms of median root mean square values were used to assess tracking accuracy for leftward and rightward halfcycles of tracking. Over the entire sample, there was a significant superiority of rightward over leftward tracking, which, given evidence for the ipsilateral mediation of SPEM at the cortical level, suggests a right hemisphere predominance in the control of SPEM in normal subjects. Individual tracking asymmetry was associated with overall tracking accuracy such that subjects with relatively deficient leftward tracking and those with a larger absolute magnitude of asymmetry had poorer overall tracking. High scores on an MMPI schizotypy measure (Sum 2-7-8-0) were significantly related to poorer overall SPEM accuracy, individual tracking asymmetry, the absolute magnitude of tracking asymmetry, and phase lag, though the subjects' sex, handedness, and crossed hand-foot dominance were found to affect the relationships between schizotypy and tracking accuracy. These findings suggest that although control of SPEM may be predominantly right hemispheric, in some persons with a vulnerability to schizophrenia spectrum disorders, expressed as poorer overall SPEM accuracy and high schizotypy scores, left hemisphere-mediated (leftward) SPEM may be particularly impaired.

Adolescent↗
PubMed1992

Lateral orientation, eye movements and dichotic listening.

Past studies have found that lateral orientation (eye or head turn) may influence hemispheric asymmetry on the dichotic listening task. The present work studied the effects of forced head and eye turn on a consonant-vowel dichotic test. Spontaneous conjugate lateral eye movements (CLEM) in response to questions were also measured. The subjects were 29 male and 25 female right-handed university students. The dichotic test was administered using a forced-attention method rather than free recall in order to control for attentional bias. As predicted, right lookers on the CLEM test, showed an enhanced right ear advantage while left lookers showed a diminished right ear advantage. This suggests that characteristic hemispheric arousal may enhance or inhibit asymmetry on perceptual laterality tests. No relationship was found between dichotic listening and forced head or eye turning. It was noted that past experiments may have failed to control for the attentional bias introduced by having the head or eyes turned to one direction.

Acoustic Stimulation↗
PubMed1989

Conjugate lateral eye movements: a second look.

It has been suggested that conjugate lateral eye movements (CLEM) are related to cerebral lateralization. Two types of research have developed: studies examining individual differences (hemisphericity) and studies examining the type of questions used to elicit eye movements (hemispheric specialization). In a 1978 review, Ehrlichman and Weinberger questioned the notion that CLEM is related to cerebral lateralization, particularly with regard to individual differences. However, since their review, a substantial number of studies have been published which are pertinent to the validity of CLEM. The following paper reviewed the validity of CLEM through three avenues, neurophysiological evidence, relationships with other measures of laterality and relation to spatial and verbal stimuli. Overall, it was concluded that there is sufficient evidence to support the CLEM model. Converging evidence from studies on EEG, electrical stimulation, ablation, brain damage, sodium amytal testing, blood flow, positron emission tomography, dichotic listening, and visual half fields was found to be, for the most part, supportive. The results for verbal and spatial task performance were mixed. Studies examining verbal abilities or a verbal to spatial comparison were generally supportive. The findings for spatial abilities alone were more equivocal. Evidence on question-type was found to be weak but positive, with about half the studies showing the predicted asymmetry and the other half reporting nonsignificant results. The implications of an interaction between hemisphericity or characteristic arousal and hemispheric specialization were also discussed.

Animals↗
PubMed1988

Torque and cerebral lateralization: a questionable link.

Past research has suggested that torque (the tendency to draw circles in a clockwise direction) may be indicative of less cerebral lateralization. This notion is based on the finding that left-handers demonstrate a greater incidence of torque than right-handers. The present study attempted to investigate this relationship using both conjugate lateral eye movements (CLEM) and handedness as indices of cerebral lateralization. Subjects were 40 male and 40 female right-handed and 16 male and 16 female nonright-handed university students. Consistent with past studies, torque was significantly related to handedness, with nonright-handers demonstrating a greater incidence of torque. However, no relationship between torque and CLEM was found. On the basis of these findings, it is argued that the observed relationship between torque and handedness may be due more to muscle mechanics of the hands rather than any relationship with cerebral lateralization.

Adult↗
PubMed1985

Alexithymia, hemisphericity, and conjugate lateral eye movements.

The conjugate lateral eye movements (CLEMs) of 102 university students were measured in conjunction with the administration of the Schalling-Sifneos Personality Scale, a self-report measure of alexithymia. There was a significant positive correlation between CLEM scores and alexithymia scores for all subjects, suggesting the existence of a relationship between right hemisphere activation and alexithymic characteristics. These results are discussed in terms of some theoretical models of alexithymia.

Adult↗
PubMed1977

Allergy and pregnancy and birth complications.

There is a positive relationship between presence of allergic disease and occurrence of pregnancy and birth complications. It is suggested that this relationship is mediated by underdevelopment of the thymus or impairment of central nervous system mechanisms of immunological response due to anoxia often associated with pregnancy and birth complications.

Asthma↗
PubMed1975

Lateral eye-movement consistency and academic aptitude: failure to replicate.

Scores on the Scholastic Aptitude Test were compared for 52 right and 46 left Ss directionally consistent and directionally inconsistent (n = 62) for conjugate lateral eye movements elicited by reflection in interpreting a series of 10 proverbs. The finding of lower Scholastic Aptitude Test scores for Ss inconsistent in direction of eye movement (Weiten & Etaugh, 1974) was not confirmed.

Achievement↗