Functions Of Cerebral Hemispheres Research Articles

Population-level laterality in foraging finless porpoises

Laterality has been reported in many vertebrates, and asymmetrical cerebral hemisphere function has been hypothesized to cause a left-bias in social behavior and a right-bias in feeding behavior. In this paper, we provide the first report of behavioral laterality in free-ranging finless porpoises, which seems to support the aforementioned hypothesis. We observed the turning behavior of finless porpoises in Omura Bay, Japan, using land-based and unmanned aerial system observations. We found a strong tendency in finless porpoises to turn counterclockwise with their right side down when pursuing and catching fish at the surface of the water. Our results suggest that this population of finless porpoises shows consistent right-biased laterality. Right-biased laterality has been observed in various foraging cetaceans and is usually explained by the dominance of the right eye-left cerebral hemisphere in prey recognition; however, right-biased laterality in foraging cetaceans may have multiple causes.

Peripheral vasoreactivity in acute ischemic stroke with hemiplegia

The association between vasomotor tone of the peripheral arteries and cerebral hemisphere function has not been established. This study analyzed the peripheral vasoreactivity of patients with acute ischemic stroke and hemiplegia using a modified Raynaud scan, which is a new technology for blood flow measurement. In this retrospective case–control study, we examined patients with unilateral weakness consistent with ischemic lesions who underwent brain magnetic resonance imaging and modified Raynaud scanning within five days from the onset of symptoms. The modified Raynaud scan was used to quantify the radioactivity of the bilateral fingertips during rest and cooling-heating thermal stress conditions and estimate vasoreactivity based on the change in the blood amount per time under rest-thermal stress. The subjects were classified into the preserved and impaired groups based on their degrees of vasomotor reaction. Based on the modified Raynaud scanning, 37 (mean age = 69.1 ± 10.6) and 32 (mean age = 62.6 ± 11.8) subjects were allocated to the preserved and impaired groups, respectively. Binary logistic regression showed that the affected limb edema (odds ratio (OR) 6.15; confidence interval (CI) 1.40–26.97; p = 0.016) and anterior circulation (OR 3.68; CI 1.01–13.48; p = 0.049) were associated with impaired vasoreactivity. The modified Raynaud scans confirmed that central lesions in the anterior circulation with hemiparesis may influence the vasoreactivity of edematous peripheral arteries. These results may inform treatment and rehabilitation for stroke patients with hemiparesis.

Dual-Task Paradigm Reveals Variation in Left Hemisphere Involvement in Verbal Processing Across the Menstrual Cycle in Normally Cycling Women.

Cognitive performance and cerebral hemispheric function are known to vary with fluctuating levels of estradiol and progesterone across the menstrual cycle in naturally cycling females. However, the literature is mixed with regard to how each hemisphere may be affected by elevated ovarian hormones. To better understand this, the current study employed a dual-task paradigm to examine potential shifts in hemispheric involvement for a verbal problem-solving task across the menstrual cycle in 30 right-handed, normally cycling young adult females (18-21 years old). To our knowledge, no study to date has utilized dual-task procedures to directly investigate the potential shifts in hemispheric function across the menstrual cycle. Specifically, participants were tested during both menses and their estimated midluteal phase where they engaged in repetitive unilateral finger-tapping while concurrently solving anagrams silently or aloud. Analysis of finger-tapping interference during the dual-task conditions revealed that solving anagrams silently was lateralized to the left hemisphere while solving anagrams aloud yielded a pattern of more bilateral hemispheric involvement, both of which were consistent across both menses and midluteal phases. Analysis of cognitive performance, however, revealed that silent anagrams performance while tapping with the right, but not left, hand significantly increased during the midluteal phase. Consistent with a number of other studies using different methodological approaches, the current dual-task findings suggest that when ovarian hormone levels are putatively elevated, there is enhanced recruitment of left hemisphere resources while performing a lateralized verbal task.

Asymmetries of total arterial supply of cerebral hemispheres do not exist

BackgroundTotal blood supply to an organ, or its part, is proportional to its function. The aim of this project was to investigate whether there is a lateralisation of total functions of cerebral hemispheres by determining differences in the arterial blood supply to left and right cerebral hemispheres. MethodsDiameters of right and left anterior, middle and posterior cerebral arteries were measured at specific sites and cross-sectional areas calculated in 203 adult brains (51 donated and dissected brain specimens and 152 cerebral arterial Computed Tomography Angiography and Magnetic Resonance Angiography images). FindingsThe sample size was large enough to provide a power of detecting as significant differences of 4%, but neither of the average cross-sectional areas of right anterior, middle and posterior cerebral arteries were significantly different from those of the anterior, middle and posterior cerebral arteries of the left side. Furthermore, combined areas of the three right cerebral arteries were not significantly different from combined areas of the left three arteries. This clearly indicates that the blood supply into the right cerebral hemisphere is not different from that of the left cerebral hemisphere. Therefore, there is no total functional lateralisation between the two cerebral hemispheres. ConclusionBrain lateralisation, frequently discussed in the literature, does not deferentially influence the total activity levels of cerebral hemispheres.

Neurocognitive Changes After Eversion Carotid Endarterectomy Under Local Anesthesia

The effects of carotid endarterectomy (CEA) on cognitive function have yet to be fully elucidated. The aim of our study was to administer a battery of cognitive tests to identify any cognitive changes occurring in a consecutive series of patients who underwent CEA using the eversion technique under local anesthesia. This prospective study was designed to analyze a consecutive series of patients undergoing eversion CEA under local anesthesia for significant carotid stenosis at our vascular surgery unit over a period of 6 months. Patients underwent tests to rule-out those who already had cognitive impairments or states of depression/anxiety capable of interfering with cognitive testing outcomes. Patients then completed a battery of 10 neurocognitive tests preoperatively and again 30 days and 4 months after surgery to assess the functions of both cerebral hemispheres as thoroughly as possible. Of the 48 patients initially considered for our study, 39 completed the follow-up. They were 71.4 ± 8.2 (mean ± SD) years of age; 30 were men and 9 were women. Six were symptomatic for carotid stenosis and 33 were asymptomatic. All patients were examined by a neurologist and underwent pre- and postoperative nuclear MRI or CT scan of the brain to identify any cerebral ischemia potentially correlated with the surgical procedure. In all cases, the cognitive test findings tended to improve postoperatively; this improvement was statistically significant in 7 tests. Post-hoc analysis confirmed an improvement between the pre- and postoperative test results. Among the different variables considered, only age <75 years seems to have influenced cognitive improvement. The effects on cognitive function of carotid stenosis, particularly CEA, is still a much debated issue. The data reported in the literature vary considerably, preventing any final conclusions from being drawn. The mechanisms capable of inducing changes in cognitive status after CEA have yet to be precisely clarified. In our study, a suitable battery of tests were used to analyze the trend of cognitive function correlating with eversion CEA under local anesthesia. Our results demonstrate substantially improved cognitive function after CEA, which was statistically significant in 7 of 10 tests. We surmise that the CEA procedure, per se, can help to protect patients against cognitive deterioration, especially in those <75 years of age.

A Valid and Reliable Clinical Determination of Footedness

To develop a valid and reliable clinical performance measure of foot dominance. Prospective cross-sectional study with repeated measures. Laboratory. A total of 175 healthy male and female subjects ages 16 to 37 years. A total of 12 lower limb functional performance skilled and unskilled tasks. Internal consistency and reliability of selected measures. Principal components factor analysis with varimax rotation resulted in tasks being grouped into 3 components with Eigen values greater than 1, which explained 55% of the variance. An inventory of 4 skilled component tasks was found to reliably determine footedness. Internal consistency derived from Cronbach's alpha produced a value of 0.819 for the skilled tasks. Three of the 4 skilled tasks were found to have excellent reliability (>0.75) with almost perfect agreement. Determining foot dominance is important in a rehabilitation setting, considering the normal laterality variation in cerebral hemisphere function, limb morphology, and motor performance parameters encountered in humans. This study developed an inventory of skilled performance tasks to reliably determine footedness. Four bilateral tasks were identified that had excellent test-retest reliability and high internal consistency and are recommended as global determinants of footedness.

Estimation of cerebral surface area using vertical sectioning and magnetic resonance imaging: A stereological study

Stereological techniques using isotropic uniform random and vertical uniform random sections have been used for surface area estimation. However, there are a few studies in which the surface area of the brain is estimated using the vertical section technique in a stereological approach. The objective of the current study was to apply the vertical section technique using cycloid test probes for estimation of cerebral surface area in magnetic resonance imaging (MRI). In this study, cerebral surface areas were estimated in a total of 13 young subjects (6 males, 7 females) who were free of any neurological symptoms and signs. The means (±S.D. ) of the surface areas were 1619.92 ± 140. 97 cm 2, 1625.69 ± 147. 58 cm 2 and 1674.69 ± 160. 60 cm 2 for 36, 18 and 12 vertical sections, respectively. The mean coefficient of error obtained by applying cycloid test lines that use a 2. 8-cm ratio of area associated with each cycloid was estimated at < 7% for the three models. No significant difference was found for each of the 36, 18 and 12 vertical sections ( p > 0.05). In addition, the three models correlated well with each other. From these results, it is concluded that the vertical section technique is an unbiased, efficient and reliable method and is ideally suited to in vivo examination of MRI data for estimating the surface area of the brain. Hence, we suggest that estimation of surface area using MRI and stereology may be clinically relevant for assessing cortical atrophy as well as for investigating the structure and function of cerebral hemispheres.

ASYMMETRY IN HAND GRIP STRENGTH AND FATIGUE IN LOW- AND HIGH-HOSTILE MEN

The present study examined the relationship between hostility level and cerebral hemispheric motor functioning of 70 left cerebral dominant men. Using the Cook-Medley Hostility Scale, the subject group was divided into thirds: One-third (N = 23) were classified as low-hostile, one-third (N = 23) were classified as high-hostile, and the remainder (N = 24) were excluded from analysis. A hand dynamometer was used to assess hand grip strength, perseveration, and fatigue, as measures of hemispheric motor functioning. Results yielded a hand-by-hostility group interaction, which indicated that high-hostile men evidenced sig nificantly less hand grip strength at the right hand and significantly greater hand grip strength at the left hand relative to low-hostile men. These results suggest that high-hostile men may experience relatively greater right-cerebral arousal relative to their low-hostile counterparts. In other results, both groups showed greater perseveration at the left hand than at the right hand. Both groups also showed significant fatigue across trials at both hands. Analysis also revealed a hand-by-trial interaction, indicating that the right hand fatigued more quickly than the left hand across trials. Resistance to fatigue at the left hand and overestimation or relative imprecision in motor movement at the left hand are discussed in terms of arousal theory. These results and others are cited as contributing inroads into distinguishing between the emotional problems of depression, anxiety, and hostility.

Comparison of intracranial self-stimulation evoked from lateral hypothalamus and ventral tegmentum: analysis based on stimulation parameters and behavioural response characteristics.

The comparison of intracranial self-stimulation (ICSS) derived across the anteroposterior axis of medial forebrain bundle (MFB) from the anterior border of lateral hypothalamus (LH) to the ventral mesencephalon including ventral tegmental area-substantia nigra (VTA-SN) in Wistar rats was assessed through stimulation parameters and behavioural response characteristics. The interpretation of response rate/charge consumption (muC/min) with respect to rectangular wave and sine wave electrical stimulation parameters suggests that the rectangular wave parameters are better in order to get the maximum responding rates. The most vigorous and robust responding was observed in the VTA or VTA-SN boundary placements, followed by placements in medial sector of LH. The acquisition of ICSS was fastest in the case of VTA-stimulation. The next site with respect to rapidity of ICSS was posterio-ventral LH. The extinction curves indicated that it is faster and exponential in case of VTA-SN, but it is slower with longer duration in case of LH-MFB. ICSS of SN were accompanied by exploratory locomotion and head bobbing. Thirty-one percent subjects with SN/VTA stimulation showed rotational behaviour. Seventy-eight percent of subjects with LH stimulations showed stimulus-bound ejaculations. Thirty-two percent of subjects with posterior LH stimulations showed biting of pedal edges. LH stimulations were accompanied by induced seizures and increased grooming in 18% and 13% of subjects, respectively. There was lateralisation of cerebral hemispheric function as right paw preference was noted in majority of rats, whether sites of stimulation were in the left or right cerebral hemisphere. The various other modes of pedal pressing operants like use of paw and mouth, alternate paw dribbling, use of head electrode assembly to manipulate the pedal were also recorded and analysed.

Functional Asymmetry in the Motor Performances of Women: Neuropsychological Effects of Depression

The influence of depression on the cerebral hemispheric motor functioning of 40 right-handed women, half of whom had been classified as depressed, the other half as nondepressed, was examined. The depressed women were also characterized by elevated state and trait anxiety, suggestive of an anxious-depressive state with heightened arousal. A hand dynamometer was used as a standardized measure of hemispheric motor functioning such as hand-grip strength, perseveration, and fatigue. Primary findings indicated that depressed women displayed significantly less perseveration at the left hand than did nondepressed women, but a nonsignificant trend only was noted for less perseveration at the right hand. These results suggest possible differential arousal of the left and right cerebral hemispheres in this sample of anxious-depressed women and are discussed in terms of arousal theory.

Gynecological chair syncope in elderly women: practical implications for general practitioners and gynecologists

Syncope is a common syndrome occurring in about 2% of those 65-69 years old, increasing to 12% in those over age 85 [1]. Syncope deserves diagnostic analysis because, while unexplained syncope is associated with a slight increased mortality rate within 1 year, when syncope can be linked to a cardiovascular cause, the 1-year mortality rate is 20% to 30% [1]. Syncope is defined as the transient loss of consciousness with a lack of responsiveness and postural tone, followed by spontaneous recovery. Consciousness is lost when the function of both cerebral hemispheres or of the brain stem reticular activating system is compromised. Interruption of cerebral blood flow and/or the occurrence of severe hypoxemia (arterial oxygen pressure Pa02 > 15 mmHg) to the cerebral hemispheres or brain stem results in loss of consciousness within 10 s [2]. A fall in systolic blood pressure less than 90 mmHg or a mean blood pressure of 30 to 40 mmHg results in syncope. Within 20 s spontaneous and evoked electrical activity ceases and a series of metabolic disturbances occur, leading to convulsive movements, and death of the cerebral cortex in 3 to 6 min [2]. The critical

Differences in dichotic listening asymmetries in depression according to symptomatology

Subjects suffering from major depressive disorder were compared to normal controls on two verbal dichotic listening tasks. Although there were no significant differences between the groups on a task primarily of language perception, significant differences were obtained on a task with an attentional component. Overall performance was lower for the depressed group and ear asymmetry was reduced. Within the depressed group ear asymmetry varied according to symptomatology; withdrawal-retardation was associated with a lack of asymmetry and anxiety with a normal right ear advantage. The results were interpreted in terms of an interaction between affect and attention, and possible underlying mechanisms of cerebral hemisphere function were discussed.

Reading efficiency and the development of left-to-right writing by the ancient Greeks.

Ancient Greeks added vowels to a consonantal language and changed their horizontal writing direction from right-to-left to left-to-right. The idea that the dextral majority in ancient Greece developed left-to-right writing solely because writing efficiency was greater is questioned. Cerebral hemispheric functions that might be involved during fixation pauses in reading suggest that horizontal ancient Greek was read more efficiently from left to right than from right to left, the other direction in which it usually was written. The same considerations suggest that horizontal consonantal scripts are read more efficiently from right to left than from left to right. The importance of boustrophedon, a continuous writing style, in the development of left-to-right writing and aspects of the reciprocity between cerebral hemispheric functioning and writing direction of vocalic scripts are discussed.

Reading Efficiency and the Development of Left-to-Right Writing by the Ancient Greeks

Ancient Greeks added vowels to a consonantal language and changed their horizontal writing direction from right-to-left to left-to-right. The idea that the dextral majority in ancient Greece developed left-to-right writing solely because writing efficiency was greater is questioned. Cerebral hemispheric functions that might be involved during fixation pauses in reading suggest that horizontal ancient Greek was read more efficiently from left to right than from right to left, the other direction in which it usually was written. The same considerations suggest that horizontal consonantal scripts are read more efficiently from right to left than from left to right. The importance of boustrophedon, a continuous writing style, in the development of left-to-right writing and aspects of the reciprocity between cerebral hemispheric functioning and writing direction of vocalic scripts are discussed.

Cerebral Hemisphere Function in Depression

Back to table of contents Previous article Next article ArticleNo AccessCerebral Hemisphere Function in DepressionJOSEPH R. BONAJOSEPH R. BONASearch for more papers by this authorPublished Online:1 Apr 2006https://doi.org/10.1176/ajp.146.3.392AboutSections ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail "Cerebral Hemisphere Function in Depression." American Journal of Psychiatry, 146(3), p. 392 Access content To read the fulltext, please use one of the options below to sign in or purchase access. Personal login Institutional Login Sign in via OpenAthens Purchase Save for later Item saved, go to cart PPV Articles - American Journal of Psychiatry $35.00 Add to cart PPV Articles - American Journal of Psychiatry Checkout Please login/register if you wish to pair your device and check access availability. Not a subscriber? Subscribe Now / Learn More PsychiatryOnline subscription options offer access to the DSM-5 library, books, journals, CME, and patient resources. This all-in-one virtual library provides psychiatrists and mental health professionals with key resources for diagnosis, treatment, research, and professional development. Need more help? PsychiatryOnline Customer Service may be reached by emailing [email protected] or by calling 800-368-5777 (in the U.S.) or 703-907-7322 (outside the U.S.). FiguresReferencesCited byDetailsCited ByNone Volume 146Issue 3 March 1989Pages 392-392 Metrics History Published online 1 April 2006 Published in print 1 March 1989

The Causes of Crime: New Biological Approaches.

Introduction: Biological factors in crime causation: the reactions of social scientists Sarnoff A. Mednick Part I. Methodological questions and implications: 1. Some cautions for the biological approach to crime causation Gordon Trasler 2. Watch out for that last variable Malcolm W. Klein 3. Implications of biological findings for criminological research David P. Farrington 4. Definitions of antisocial behaviour in biosocial research Preben Wolf Part II. Evidence for the role of genetics: 5. Genetic factors in the etiology of criminal behaviour Sarnoff A. Mednick, William F. Gabrielli, Jr., and Barry Hutchings 6. Genetic and environmental factors in antisocial behaviour disorders C. R. Cloninger and I. I. Gottesman Part II. Psychophysiological and neurophysiological factors: 7. Autonomic nervous system factors in criminal behaviour Peter H. Venables 8. Electroencephalogram among criminals Jan Volavka 9. Childhood diagnostic and neurophysiological predictors of teenage arrest rates: an eight-year prospective study James H. Satterfield Part IV. Neurological factors: 10. Cerebral dysfunctions and persistent juvenile delinquency W. Buikhuisen 11. Violent behaviour and cerebral hemisphere function Israel Nachshon and Deborah Denno 12. Perceptual asymmetries and information processing in psychopaths Robert D. Hare and John F. Connolly Part V. Biological Factors: 13. The neuroendocrinology and neurochemistry of antisocial behaviour Robert T. Rubin 14. Testosterone and adrenaline: aggressive antisocial behaviour in normal adolescent males Dan Olweus 15. Personality correlates of plasma testosterone levels in young delinquents: an example of person-situation interaction? Daisy Schalling 16. Metabolic dysfunctions among habitually violent offenders: reactive hypoglycemia and cholesterol levels Matti Virkkunen Part VI. Treatment Issues: 17. The role of psychosurgical studies in the control of antisocial behaviour Mark A. J. O'Callaghan and Douglas Carroll 18. Pharmacological approaches to the treatment of antisocial behaviour C. R. Cloninger Indexes.

Stages of information processing and cerebral hemispheric differences in random shape recognition

The purpose of this experiment was to investigate the differences of cerebral hemisphere function with respect to the way visual pattern information is stored in the long-term memory. The shape recognition in the left and right visual fields was measured after the subjects were trained to associate the shapes with relevant verbal labels, irrelevant verbal labels, or no verbal labels. Subjects were given a shape recognition test by the visual half-field presentation and both free- and aided-recall tests for retention of associated verbal labels. Results indicated that accuracy of recognition of shapes in the left visual field was greater than in the right visual field. Pretraining condition produced a significant main effect but no differential field effect. While irrelevant verbal labeling and observation conditions recognized the stimulus with equal reaction time in either visual field, the latency of relevant verbal labeling condition was longer in right visual field than in left visual field. These results were discussed in terms of the differences of cerebral hemisphere function in each stage of information processing.

Modulation of spinal motor asymmetry by neuroleptic medication of schizophrenia patients.

The effects of chlorpromazine treatment on spinal motor asymmetry was studied in right-handed chronic schizophrenia patients. Spinal motor asymmetry and lower motor neuron excitability were tested by the Hoffmann reflex recovery curve. In drug-free patients, the Hoffmann reflex recovery curve from the left leg was significantly higher than that from the right leg as in the healthy subjects. This spinal motor asymmetry disappeared and even reversed within three weeks of the neuroleptic treatment. The chlorpromazine medication lowered the left recovery curve predominantly, and slightly augmented the right recovery curve. These results do not support the hypothesis that schizophrenia may be related to an overactive, and yet functionally deficient, dominant hemisphere. It was concluded that the cooperative function of both cerebral hemispheres should be taken into consideration to explain the neural mechanisms of schizophrenia.

Sleep and recovery from aphasia after closed head injury

Sleep disturbances after cranial cerebral trauma are well-known. A few studies have attempted to relate recovery of rapid eye movement (REM) sleep with cognitive recovery in general and recovery from aphasia in particular. This paper review the literature on sleep and recovery of neuropsychological function with emphasis on the recovery from aphasic disturbance. Sleep data on 20 closed head injury patients and their neuropsychological characteristics are reported. Specific case examples of head injury patiens with or without aphasia who show different sleep patterns are also illustrated. It is concluded that recovery from aphasia may, in fact, be related to the return of normal percent REM sleep and that this phenomenon may be particularly reflective of intact right cerebral hemisphere function. Research linking REM sleep to right hemisphere function is also presented. Potentially sleep studies might be used to help predict recovery from aphasia after traumatic brain injury in young adults.

Cerebral hemisphere function and laterality of migraine.

We report preliminary findings of a study exploring the hypothesis that migraine is the experience of a protective cerebrovascular mechanism arising in response to unilateral cerebral information overload. The necessary population to be studied, namely those with exclusive one-sided migraine, proved to be rare. The measures of cerebral hemisphere function were the verbal and non-verbal scales of Wechsler's Adult Intelligence Scale. Preliminary results suggest that it is worthwhile continuing to explore the notion using additional and more sophisticated measures.