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At least 883 records · Page 49Linked to original sources
PubMed1984

Effects of gender and alcoholism on verbal and visual-spatial learning.

Sex differences in cognitive abilities of chronic alcoholics were investigated using a paired-associates learning test with separate but similarly structured verbal and visual-spatial components. Four groups of 35 subjects each, equated for age and education, were tested: male and female alcoholics, and male and female community control subjects. As expected, sex differences were found on the component tasks: overall, nonalcoholic women performed significantly better than nonalcoholic men on the verbal measure, and nonalcoholic men performed better than nonalcoholic women on the visual-spatial measure. Nonalcoholic men had a larger discrepancy between component scores than nonalcoholic women, suggesting greater lateralization of cognitive functions; however, this difference did not reach significance. The effects of alcoholism were different for the sexes. Alcoholic women were not impaired on either the verbal or visual-spatial measure, but the alcoholic men demonstrated deficits in visual-spatial performance. In addition, they showed less difference between verbal and visual-spatial component scores than the other groups, suggesting that alcoholism attenuated the effects of hemispheric specialization for cognitive abilities normally found in men.

Adult↗
PubMed1988

The accuracy of the dichotic, the visual half-field, and the intracarotid sodium amytal memory tests in preoperative neuropsychological investigation of epileptic patients.

Three methods for determining the lateralization of memory functions in patients with pharmacologically resistant intractable partial epilepsy were compared and evaluated. The three methods studied were a dichotic memory test, a visual half-field memory test, and an intracarotid Sodium Amytal memory test. A total of 35 epileptic patients considered for surgical therapy and a group of 20 non-epileptic control subjects took part in the study. The results show that the three tests tap different memory functions and that each of the test pick up a memory dysfunction in the hemisphere indicated by EEG recordings. In combination with an extensive neuropsychological test battery, the three methods produce data that concur with the evaluation made of EEG recordings.

Amobarbital↗
PubMed1992

Frontal lobe function in amyotrophic lateral sclerosis: a neuropsychologic and positron emission tomography study.

In this study the regional cerebral glucose utilization and the neuropsychological performance of patients with amyotrophic lateral sclerosis (ALS) was investigated. Special attention was given to neuropsychological tests thought to mirror frontal lobe dysfunction. The regional cerebral glucose utilization was studied in 18 patients using high-resolution positron emission tomography. Clinically all patients displayed upper and lower motor neurone signs. In ALS patients glucose metabolism was significantly reduced in the frontal and in the entire cortex compared with controls; no changes were seen in the cerebellum. Comprehensive neuropsychological assessment of ALS patients compared to a pair matched control group revealed mild frontal dysfunction which in part significantly correlated with reduced glucose metabolism in the cortex and subcortical structures. We conclude that in patients with ALS, glucose consumption is decreased in parts of the brain other than the motor cortex accompanied by mild neuropsychological deficits based on the tests employed in this study.

Adult↗
PubMed2004

Asymmetric cochlear processing mimics hemispheric specialization.

Otoacoustic emissions or OAEs (reflections of cochlear energy produced during the processing of sound) were measured in response to two types of stimuli, rapid clicks and sustained tones, in each ear of neonates. OAEs were larger to tones when elicited in the left ear and to clicks when elicited in the right. This finding is similar to those of enhanced processing of tones in right auditory cortical areas and of rapid stimuli on the left, given strong crossed connections from ear to brain. These findings indicate that processing at the level of the ear may facilitate lateralization of auditory function in the brain.

Acoustic Stimulation↗
PubMed1980

Limulus brain modulates the structure and function of the lateral eyes.

At night efferent optic nerve activity generated by a circadian clock in the Limulus brain changes the structure of the photoreceptor and surrounding pigment cells in the animal's lateral eyes. The structural changes allow each ommatidium to gather light from a wider area at night than during the day. Visual sensitivity is thereby increased, but spatial resolution is diminished. At daybreak efferent activity from the clock stops, the structural changes reverse, and the field of view of each ommatidium decreases. The cyclic changes are endogenous and continue in the dark. Thus, under the control of a circadian clock, the Limulus eye exchanges its daytime acuity for greater sensitivity at night.

Action Potentials↗
PubMed2001

Fighting from the right side of the brain: left visual field preference during aggression in free-ranging male tree lizards (Urosaurus ornatus).

In a field study on male tree lizards (Urosaurus ornatus), we tested the hypothesis that aggression is lateralized, and predicted that resident males should preferentially use the left-visual field (LVF)/right hemisphere in aggressive interactions with other males. This prediction was based on results for a small but taxonomically diverse number of vertebrates indicating a left-eye preference/ right hemisphere specialization for aggression. Many lizards use postural displays to signal aggression and lateral eye placement prevents binocular vision of such displays. The fullshow is an aggressive display that is typically performed with the body held perpendicular to that of the opponent. We staged male-male encounters by introducing stimulus males to free-ranging males (hereafter called focal males), and then recorded both the focal male's behavior and the visual field that he used to view the intruder while performing fullshow displays. When intruders were introduced in the right visual field (RVF), focal males were equally likely to use either the LVF or RVF to perform their first fullshow. However, in these RVF introductions focal males were more likely to turn and use the LVF if the intruder was smaller. In contrast to RVF introductions, in LVF introductions focal males were significantly more likely than expected by chance to continue to use the LVF to view the intruder when performing the first fullshow. Furthermore, if focal males performed their first fullshow with the intruder in their LVF, they subsequently gave more aggressive displays than focal males that performed their first display with the intruder in their RVF. Additionally, charge (a highly aggressive behavior that usually leads to direct physical contact and a bite) was significantly more likely to occur while the LVF was being used to view the opponent. These results are consistent with the hypothesis that aggression is lateralized to the right hemisphere. This study is one of only a few examples of laterality of brain function demonstrated in a free-ranging vertebrate.

Aggression↗
PubMed1989

A functional approach to lateral fixation in bilateral abductor cord paralysis.

A modification of the Clerf arytenoidopexy treatment for bilateral vocal cord paralysis is described; it consists of an external approach with complete unilateral division of the posterior cricoarytenoid and interarytenoid muscles. The entire arytenoid is next mobilized and tilted laterally, then fixed into position along the posterior margin of the thyroid cartilage by two or three permanent retention sutures. Careful placement of these sutures renders the laryngeal mucosa maximally undisturbed and is largely responsible for the predictable results achieved with this technique. During the past 2 years, 18 patients received this static procedure, and 17 of 18 (94%) required a tracheotomy as part of the treatment because of a uniformly severe degree of glottic obstruction. All tracheotomy patients have been permanently decannulated (on an average) 14 days after surgery. The evaluation of each patient included pre- and post-operative measurements of airway resistance that correlated well with the width of the posterior commissure, and proved invaluable in successful decannulation efforts.

Adolescent↗
PubMed2004

Material-specific recognition memory deficits elicited by unilateral hippocampal electrical stimulation.

Although the medial temporal lobe is thought to be critical for recognition memory (RM), the specific role of the hippocampus in RM remains uncertain. We investigated the effects of transient unilateral hippocampal electrical stimulation (ES), subthreshold for afterdischarge, on delayed item RM in epilepsy patients implanted with bilateral hippocampal depth electrodes. RM was assessed using a novel computer-controlled test paradigm in which ES to left or right hippocampus was either absent (baseline) or synchronized with item presentation. Subsequent yes-no RM performance revealed a double dissociation between material-specific RM and the lateralization of ES. Left hippocampal ES produced word RM deficits, whereas right hippocampal ES produced face RM deficits. Our findings provide the first demonstration in humans that selective unilateral stimulation-induced hippocampal disruption is sufficient to produce impairments on delayed RM tasks and provide support for the material-specific laterality of hippocampal function with respect to RM.

Adult↗
PubMed2000

Recognition of emotional facial expressions in depressed children and adolescents.

Of the neurobiological models of children's and adolescents' depression, the neuropsychological one is considered here. Experimental and clinical evidence has allowed us to identify a lateralization of emotional functions from the very beginning of development, and a right hemisphere dominance for emotions is by now well-known. Many studies have also correlated depression with a right hemisphere dysfunction in patients of different ages. The aim of our study was to analyze recognition of different facial emotions by a group of depressed children and adolescents. Patients affected by Major Depressive Disorder recognized less fear in six fundamental emotions than a group of healthy controls, and Dysthymic subjects recognized less anger. The group of patients' failure to recognize negative-aroused facial expressions could indicate a subtle right hemisphere dysfunction in depressed children and adolescents.

Adolescent↗
PubMed2001

Accordance between EEG alpha power and dual task performance for different visual cognitive tasks.

Evidence from clinical and experimental studies suggests that the left hemisphere is preferentially engaged in language processing and mathematical-analytic tasks while the right is involved with spatial relations and synthetic tasks. The purpose of the present study was to investigate accordance between dual task paradigm (effects of concurrent cognitive tasks on right- and left-hand finger tapping frequency) and EEG alpha power changes, which are used to conduct research in lateralization of cognitive function. Subjects performed reading, face recognition and line orientation tasks. First, the EEG was recorded during the tasks and, after six months, the dual task was carried out using the same cognitive tasks. Statistical analysis yielded no significant main effect for the hemispheres, performing hand and three cognitive tasks separately for the dual task and the EEG alpha power changes. However, significant correlation between the two methods was found, indicating the left parietal activation for the reading task, the right temporal activation for the line orientation task, and both hemispheric activation for the face recognition task. Results first suggest a significant accordance between dual task performance and EEG alpha asymmetry studies.

Adolescent↗
PubMed1998

Dichotic memory: paradoxical effect of removing a left frontal gyrus: a case study.

A 27-year-old right-handed woman was operated with resection of an epileptogenic lesion, a nonmalignant tumor, in the left frontal lobe. The surrounding cortical and subcortical tissue in the tumor-containing gyrus was also resected. Care was taken during the operation not to interfere with motor or language related cortical areas. Pre- and postoperatively, she was tested with a dichotic memory test. In the preoperative test, she showed a marked Left Ear Advantage. In the corresponding tests on the second and fourth postoperative days and at follow-up, her performance had changed to a Right Ear Advantage. A possible explanation of this result is that neighboring cortical areas involved in hemispheric specialization for lateralized, verbal cognitive functions are suppressed by a focal epiletogeneic activity caused by the tumor. The subsequent removal of this influence allowed these cortical areas to function normally.

Adult↗
PubMed2000

Obesity, disease, and functional limitation in later life.

Little is known about the effects of obesity late in life. Using data from the Longitudinal Study of Aging and the Assets and Health Dynamics of the Oldest Old Survey, this study finds an increased prevalence of obesity, over time, among those 70 and older. Obesity is related most strongly to limitations in activities of daily living (ADLs) for women and to activities related to mobility. One ADL, eating, has a negative association to obesity. Obesity is associated with an increased prevalence of arthritis, diabetes, and hypertension. These results are cross-sectional and are based on self-reports of height and weight; they must be interpreted cautiously.

Activities of Daily Living↗
PubMed1975

[Lateralization of mental functions at the subcortical level (according to material from stereotaxic surgery)].

In 26 patients with expressed signs of parkinsonism the authors studied the state of higher cortical functions prior to and following stereotaxic operations. The results of such studies point to a distinct connection between the changes of certain mental processes and the side of the operation. It was demonstrated that the subcortical structures of the left and right hemisphere participate in the mnestic function in different ways. The specificity and different directions of postoperative changes in the higher cortical functions may in the opinion of the authors speak in favour of a certain specificity in the contributed organization of mental processes on behalf of the subcortical structures.

Adult↗
PubMed2003

[Mixed aphasia with jargonographia in a right-handed patient].

We report a case of crossed aphasia with jargonagraphia in a forty-eight year old right handed monolingual man without family history of handedness or prior neurological illness. He developed a right temporo-insulo-parietal hamatomae documented by CT scan and accompanied by aphasia, left hemineglect, left hemiplegia, left lateral homonymous hemianopsia. The oral language was reduced and writing language was characterised by jargon. The writing and oral comprehension were preserved. This aphasia suggested a relationship between cerebral lateralization of language function and manual preference and the similarity between childhood aphasia and crossed aphasia in right-handed patients.

Aphasia↗