Role of the right brain hemisphere in training for the operator work

Functional state of the human right brain hemisphere was studied during simulation of 4-hour operator's training work with a computer in novel conditions. Participants of the experiments differed in the degree of extraversion and baseline level of cortical activity. The obtained results suggest that the role of the right hemisphere in the process of simulated activity consists in reception and primary processing of information. This hemisphere is not involved in the correction of cortical activation to the optimal level of activity, which is necessary for the efficient performance of a task.     

Semantic processing and right hemisphere

Although language is a function traditionally attributed to the left hemisphere, experimental and clinical reports indicate that the right hemisphere may also have a capacity to process verbal information. Indeed, some attributes of words, including their concreteness, imageability and emotional component, have been shown to be associated with right-hemispheric processing capacities. In addition, studies on brain-damaged, split-brain patients and studies realized with neuroimaging techniques have also suggested that the right hemisphere has some linguistic capacities. The main objective of this article is to review specific contribution of right cerebral hemisphere to semantic processing from three complementary approaches: (1) divided visual-field experiments with healthy participants, (2) studies of patients with acquired lesions of both left and right hemispheres, and (3) neuroimaging studies.     

Estrogen therapy affects right hemisphere functioning in postmenopausal women

It has been suggested that hormone therapy (HT) in postmenopausal women differentially affects verbal and visuo-spatial abilities which mainly rely on left hemisphere (LH) and right hemisphere (RH) functioning, respectively. Thus, it seems likely that HT-related effects on cognition are driven by associated hormonal changes and their impact on functional brain organization, and functional cerebral asymmetries (FCAs) in particular. The present study investigated HT-related effects on FCAs in sixty-seven postmenopausal women who received hormone therapy either with estrogen (E) alone (n =  14), an E-gestagen combination (n =  22) or without HT (control group, n =  31). Saliva levels of free E and progesterone (P) were analyzed using chemiluminescence assays. FCAs were measured with the visual half-field (VHF) technique using a word matching and a figural comparison task. In agreement with previous results, a postmenopausal control group showed a left hemisphere (LH) advantage in the verbal task and a right hemisphere (RH) advantage in visuo-spatial processing. In contrast, both HT groups revealed significantly reduced FCAs in the figural comparison task as a result of an E-related decrease in RH performance. The findings suggest that E-therapy in postmenopausal women can affect visuo-spatial abilities by modulating the functional brain organization and RH functioning in particular.     

Some peculiarities of brain phospholipids in deep sea fishes]

Total phospholipids (PL) as well as the content of various phospholipid classes and their fatty acid composition have been investigated in the brain of mesopelagic and abyssal marine teleosts. These species were compared to shallow water ones. The brain of deep sea fishes was found to be very poor in PL as compared to the brain of mesopelagic ans surface water species. No differences concerning the brain PL content were revealed between the two last mentioned groups. The relative content of separate PL classes was very similar in all the species studied irrespectively of the depth of their habitat. Peculiarities were found in fatty acid composition of individual PL from deep sea species as compared to surface ones. The deeper the habitat, the lower the content of saturated fatty acids, especially of the stearic acid. The lowest content of saturated fatty acids, maximum level of polyenoic fatty acids as well as some peculiarities in the relative content of particular fatty acids were found in the brain of ultraabyssal (6, 000 m) Leucicorus sp.     

Selective interference for the right hemisphere in a task of visual-motor exploration

Simple reaction times to lateralized visual stimuli were studied in normal subjects while they were carrying out a concomitant task. The concomitant task consisted in the exploration of a visual maze presented in the middle of a screen. Regardless of the hand used, the concomitant task produced a specific lengthening of the responses to stimuli located in the left visual field. It is concluded that the right hemisphere plays a major role in the organization of ocular movements during active exploration of visual environment.     

Marijuana: Differential effects on right and left hemisphere functions in man

Marijuana, smoked at moderate doses, produced a differential impairment of the reaction times of right-handed males to pictorial stimuli presented to the left and right cerebral hemispheres. After smoking marijuana responses to pictorial stimuli presented to the right hemisphere were slowed significantly less than to the left hemisphere. Responses to verbal stimuli (trigrams) were slowd equally in both hemispheres, preserving an initial left hemisphere superiority for this material. This suggests that marijuana may differentially change the processing speed or relative dominance of man's two cerebral hemispheres, depending on the nature of the material being processed.     

Cerebral specialization during lucid dreaming: A right hemisphere hypothesis.

Research has shown that certain individuals are able to carry out prearranged tasks while lucid dreaming, and that these tasks produce physiological effects on the body similar to what is observed during waking. It was hypothesized that the difficulty of performing cerebrally lateralized tasks during a lucid dream would vary with the dominant hemisphere for that task, with less difficulty for right hemisphere tasks. Twenty-seven participants rated the difficulty of performing three matched pairs of left hemisphere and right hemisphere tasks, first in a lucid dream, and later in their waking imagination. Results indicated right hemisphere dominance during lucid dreaming, especially among right-handed participants. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Human face recognition in sheep: lack of configurational coding and right hemisphere advantage

Face recognition in sheep is qualitatively similar to that in humans in terms of its left visual field bias, and the effects of expertise and configural coding. The current study was designed to determine whether such effects are species specific by investigating the case of sheep recognising humans. It was found that the sheep could identify human faces and while they showed a small inversion-induced decline in discriminatory performance, this was significantly less than seen with sheep faces. In other aspects, there were qualitative differences with human face recognition compared with conspecific recognition. In contrast with sheep faces there was no left visual field advantage in the recognition of human faces and the internal features were not used at all as visual cues. The data suggest that these sheep, whilst being extensively exposed to interactions with humans, were unable to identify them with all the same 'expert' methods as were used to discriminate other sheep. This suggests that different neural systems may, to some extent, be used for recognition of sheep as opposed to human faces. The relative contribution to differential neural processing of the faces of the different species and the role of expertise are discussed.     

Elevated oxidative stress and endothelial dysfunction in right coronary artery of right ventricular hypertrophy

Remodeling of right coronary artery (RCA) occurs during right ventricular hypertrophy (RVH) induced by banding of the pulmonary artery (PA). The effect of RVH on RCA endothelial function and reactive oxygen species (ROS) in vessel wall remains unclear. A swine RVH model (n = 12 pigs) induced by PA banding was used to study RCA endothelial function and ROS level. To obtain longitudinal coronary hemodynamic and geometric data, digital subtraction angiography was used during the progression of RVH. Blood flow in the RCA increased by 82% and lumen diameter of RCA increased by 22% over a 4-wk period of RVH. The increase in blood flow and the commensurate increase in diameter resulted in a constant wall shear stress in RCA throughout the RVH period. ROS was elevated by ～100% in RCA after 4 wk of PA banding. The expressions of p47(phox), NADPH oxidase (NOX1, NOX2, and NOX4) were upregulated in the range of 20-300% in RCA of RVH. The endothelial function was compromised in RCA of RVH as attributed to insufficient endothelial nitric oxide synthase cofactor tetrahydrobiopterin. In vivo angiographic analysis suggests an increased basal tone in the RCA during RVH. In conclusion, stretch due to outward remodeling of RCA during RVH (at constant wall shear stress), similar to vessel stretch in hypertension, appears to induce ROS elevation, endothelial dysfunction, and an increase in basal tone.     

Age-related peculiarities of glutathione content changes in the brain of rats during immobilization stress

The work is aimed at studying age-related peculiarities as regards glutathione content changes in the brain of rats under immobilization stress. It has been established that some changes in the content of reduced glutathione take place in the brain in the process of ontogenesis. During immobilization stress the content of this metabolite decreases in the brain of all age groups of rats under study. To a greater extent this shift manifests itself in 2- and 24-month-old rats which are characterized by more active stress-stimulated free-radical processes in the brain and by an initially higher level of reduced glutathione.     

Three-dimensional chromatin organization in brain function and dysfunction

The three-dimensional (3D) organization of chromatin within the nucleus is now recognized as a bona fide epigenetic property influencing genome function, replication, and maintenance. In the recent years, several studies have revealed how 3D chromatin organization is associated with brain function and its emerging role in disorders of the brain. 3D chromatin organization plays a crucial role in the development of different cell types of the nervous system and some neuronal cell types have adapted unique modifications to this organization that deviates from all other cell types. In post-mitotic neurons, dynamic changes in chromatin interactions in response to neuronal activity underlie learning and memory formation. Finally, new evidence directly links 3D chromatin organization to several disorders of the brain. These recent findings position 3D chromatin organization as a fundamental regulatory mechanism poised to reveal the etiology of brain function and dysfunctions.