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Results for “Functional Laterality”

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PubMed1984

Differential laterality of hand function in right-handed and left-handed boys.

This study was designed to investigate differences in the degree of manual lateralization between right-handed and left-handed normal boys. Sixty-three 5, 7, and 9 year olds were tested on the Minnesota Rate of Manipulation Test (displacing subtest and turning subtest), the Finger Tapping Test, the Purdue Pegboard (placing subtest and assembly subtest), and the Southern California Motor Accuracy Test--Revised. Significant differences between right- and left-handed subjects were obtained on two of the six measures, and a third measure approached significance, with less lateralization among the left handers than among the right handers. Subsequent analyses indicated that differences in lateralization were significant or near-significant in the 5 and 7 year olds. By 9 years of age, right- and left-handed subjects no longer differed in the degree of laterality. Differences in degree of laterality, or the lack of such differences, between young right- and left-handed boys might be a function of the nature of the fine motor task or a function of the child's previous experience with the task.

Age Factors↗

PubMed2005

Handedness, functional cerebral hemispheric lateralization, and cognition in male-to-female transsexuals receiving cross-sex hormone treatment.

This study examined the impact of sex hormones on functional cerebral hemispheric lateralization and cognition in a group of male-to-female transsexuals receiving cross-sex hormone therapy compared to eugonadal men with a male gender identity. Cerebral lateralization was measured with a handedness questionnaire and a visual-split-field paradigm and cognitive tests sensitive to sex hormone exposure (identical pictures, 3-D mental rotation, building memory) were also administered. Endocrine measures on the day of participation for transsexual and control subjects included total testosterone, free testosterone, estradiol, gonadotropins, and sex hormone binding globulin concentrations. Compared to controls, male-to-female transsexuals had elevated estradiol and sex hormone binding globulin concentrations and suppressed testosterone concentrations. Transsexual subjects showed a trend toward less exclusive right-handedness than controls. No group differences were observed on the visual-split-field or cognitive tasks. No direct associations were observed between endocrine measures and the laterality measures and cognitive performance. Previous observations of female-typical patterns in cerebral lateralization and cognitive performance in male-to-female transsexuals were not found in the current study.

Adult↗

PubMed2004

How early experience matters in intellectual development in the case of poverty.

Experiments with rodents indicate that severe early psychological and social deprivation has lasting detrimental effects on learning ability that are not remedied by exposure to enriching experiences in adulthood. Findings indicate that environmental adversity early in life works to limit the development of intelligence with consequences for later functioning. Animal experiments are best viewed as supplying a rationale for early intervention in disadvantaged infants and children who would otherwise be likely to evince low intellectual capabilities later in life. Animal experiments conducted to date do not support an interpretation that early enrichment necessarily boosts later intellectual performance beyond the normal or species-typical range. They indicate that early intervention promotes normative development by preventing adverse early rearing conditions from leading to negative consequences for cognitive ability and self-regulation. The Abecedarian Project, an early enrichment intervention with infants from economically deprived backgrounds, is presented as an example of how early experience matters in terms of human intellectual development in disadvantaged populations. The results of that program reflect what one would expect from the rodent studies mentioned above.

Animals↗

PubMed2005

Parasagittal asymmetries of the corpus callosum.

Significant relationships have been reported between midsagittal areas of the corpus callosum and the degree of interhemispheric transfer, functional lateralization and structural brain asymmetries. No study, however, has examined whether parasagittal callosal asymmetries (i.e. those close to the midline of the brain), which may be of specific functional consequence, are present in the human brain. Thus, we applied magnetic resonance imaging and novel computational surface-based methods to encode hemispheric differences in callosal thickness at a very high resolution. Discrete callosal areas were also compared between the hemispheres. Furthermore, acknowledging the frequently reported sex differences in callosal morphology, parasagittal callosal asymmetries were examined within each gender. Results showed significant rightward asymmetries of callosal thickness predominantly in the anterior body and anterior third of the callosum, suggesting a more diffuse functional organization of callosal projections in the right hemisphere. Asymmetries were increased in men, supporting the assumption of a sexually dimorphic organization of male and female brains that involves hemispheric relations and is reflected in the organization and distribution of callosal fibers.

Adult↗

PubMed2003

Sleep-related consolidation of a visuomotor skill: brain mechanisms as assessed by functional magnetic resonance imaging.

Subjects were trained on a pursuit task in which the target trajectory was predictable only on the horizontal axis. Half of them were sleep deprived on the first post-training night (n = 13). Three days later, functional magnetic resonance imaging revealed task-related increases in brain responses to the learned trajectory, as compared with a new trajectory. In the sleeping group (n = 12) as compared with the sleep-deprived group, subjects' performance was improved, and their brain activity was greater in the superior temporal sulcus (STS). Increased functional connectivity was observed between the STS and the cerebellum and between the supplementary eye field and the frontal eye field. These differences indicate sleep-related plastic changes during motor skill learning in areas involved in smooth pursuit eye movements.

Adult↗

PubMed1999

Brain structure and neurocognitive and behavioural function in adolescents who were born very preterm.

BACKGROUND: Infants born very preterm (<33 weeks) are at increased risk of neurocognitive deficits. Their neurodevelopmental outcome up to age 8 years can be predicted by neonatal ultrasonography, but little is known of their later function. We investigated the effect of very preterm birth on brain structure and neurocognitive and behavioural functioning in adolescence. METHODS: A cohort of 105 infants born before 33 weeks of gestation in 1979-80 had ultrasonographic scans at University College Hospital, London, and were prospectively examined at 1, 4, and 8 years. At age 14-15 years, 72 of those who remained in UK (cases) and 21 age-matched full-term controls underwent brain magnetic resonance imaging (MRI), as well as neurological, cognitive, and behavioural assessment. MRI images were assessed by two neuroradiologists unaware of ultrasonographic findings or case or control status. FINDINGS: Of the 72 cases, 40 had unequivocally abnormal MRI and 15 had equivocal scans. Of the 21 controls, one had abnormal and five equivocal MRI. Abnormalities of ventricles, corpus callosum, and white matter were especially common in cases. More brain lesions were identified by MRI than by neonatal ultrasonography. The cases had significantly more reading, adjustment, and neurological impairments than controls, but their behaviour was significantly related to MRI abnormality. INTERPRETATION: Individuals born very preterm show an excess of neurocognitive and behavioural problems in adolescence, and more than half have abnormal MRI brain scans.

Adolescent↗

PubMed1989

Synaptic plasticity in the hypoglossal nucleus of female canaries: structural correlates of season, hemisphere, and testosterone treatment.

The caudal portion of the hypoglossal nucleus (nXIIts) contains the motor neurons that control the syrinx in songbirds. In canaries, song occurs seasonally, is principally produced by males, and appears to be produced predominantly by muscles on the left side of the syrinx. The present study measures the effect of seasonal change and manipulation of testosterone levels on synapse number and morphology in nXIIts in adult female canaries. We find that synapse density is lower in testosterone-treated birds than in control birds and lower in fall than in spring. The number of vesicles per presynaptic profile increases in the spring as a result of a general increase in this measure in all synapses. The number of vesicles per presynaptic profile also increases with testosterone treatment, primarily due to an increase in the proportion of synapses associated with unusually high vesicle counts. Together, these changes suggest that large reserves of neurotransmitter may be necessary to sustain singing. Several ultrastructural differences between hemispheres are found. Postsynaptic thickenings are longer, and postsynaptic processes are larger on the left side than on the right side. In the spring, there are more vesicles per synapse on the left than on the right, but this lateralization is reversed in the fall. Thus, lateralization of song production is associated with lateral asymmetries in synapse morphology. These hemispheric differences are relatively small, like those seen at the light microscope level, encouraging further consideration of peripheral as well as CNS sources of functional lateralization. The seasonal and testosterone-induced changes in synapse number and morphology may be components of the periodic reorganization of canary vocalization.

Animals↗

PubMed1993

Functional integration of cortical grafts placed in brain infarcts of rats.

Five to 6 days after a right middle cerebral artery occlusion, a cell suspension of fetal neocortex was grafted into the infarcted area of adult spontaneously hypertensive rats. Three to 17 months later, functional integration of the grafts into the afferent somatosensory pathway was tested using the 2-[14C]deoxyglucose method for estimation of glucose utilization. Grafted rats (n = 8) and control rats (n = 5) with no arterial occlusion were stimulated in the left vibrissal region resulting in an increased glucose utilization in the left trigeminal sensory nucleus and the right ventroposterior nucleus of the thalamus, whereas the same regions in a group (n = 5) of nonstimulated grafted rats were not activated. Glucose uptake in the right somatosensory cortex of control rats was 96 +/- 5 (mean +/- SEM) mumol/100 gm/min. Neocortical grafts consumed less glucose than cortex in control rats but the vibrissae-stimulated group displayed a 110% higher value than the nonstimulated grafted group (32 +/- 5 vs 15 +/- 2, p < 0.05). We conclude that graft glucose metabolism is increased following stimulation of the host somatosensory pathway, which demonstrates that transplanted neurons can be functionally integrated with neural circuitries of the host after an ischemic insult.

Animals↗

PubMed2004

Plasticity for recovery, plasticity for development: cognitive outcome in twins discordant for mid-childhood ischemic stroke.

Cognitive and language profiles in a set of likely monozygotic 13-year-old twins raised together and discordant for an extensive left hemisphere stroke are described 6 years post-stroke. Recovery differed across four skill profiles, created based on a model of plasticity. Full recovery of lost skills and full or partial development of new skills typically involved either semantic memory or right hemisphere lateralized functions such as visual perception skills. Limited development of new skills and full or partial recovery of lost skills took place in either active verbal memory or oral language skills that are left hemisphere lateralized. Language skills concerned with real-time lexical retrieval, or the use and understanding of morphology and grammar, phonological processing skills, and auditory working memory were least likely to recover and continue to develop.

Achievement↗

PubMed1998

The complex relation between myocardial viability and functional recovery in chronic left ventricular dysfunction.

Preserved myocardial viability and recurrent symptomatic ischemia are the most widely accepted criteria indicating that coronary revascularization should take place in patients with postischemic left ventricular dysfunction. However, the presence of viable myocardium within the infarct zone does not necessarily imply recovery of function after coronary revascularization. The complex relation between the extent of transmural necrosis and the degree of residual perfusion within the infarct area plays an important role. However, independently of functional recovery, cell viability may have important clinical implications, since it may improve long-term prognosis by attenuating left ventricular remodeling processes. Several different methods are used to detect hibernating myocardium. Mounting evidence suggests that thallium-201 scintigraphy is most sensitive in identifying tissue viability, whereas dobutamine echocardiography is most specific in predicting functional recovery after revascularization. In between, myocardial contrast echocardiography is the only technique able to evaluate the microvascular integrity that is a condition sine qua non for both cell viability and later functional recovery. Combined information derived from these 3 different approaches might be considered as the best way to understand how the combination of contractile, viable but noncontractile, and dead tissue affect resultant function and prognosis.

Cardiotonic Agents↗

PubMed1974

Functional studies of the parotid and pancreas glands in amyotrophic lateral sclerosis.

Functional studies of the pancreas and parotid glands are reported in 17 patients with amyotrophic lateral sclerosis (ALS). The exocrine function of the pancreas was studied by measuring amylase concentration after stimulation with the endogenous secretin-pancreozymine test (ESP). Under these conditions, the pancreatic amylase concentration in ALS patients was found to be markedly decreased by about 45% when compared with those of healthy control subjects. Different conclusions in the literature about a possible impairment of the exocrine pancreas in ALS patients induced us to study the function of the parotid gland, which has close structural, functional, and physiopathological relationship with the pancreas. Flow rate and bicarbonate concentration of parotid saliva were measured after indirect stimulation (intraoral citric acid) and direct stimulation (pilocarpine). After indirect stimulation, both parotid flow rate and bicarbonate concentration from ALS patients were found to be decreased by about 66% and 70% respectively, when compared with controls. On the other hand, direct stimulation with pilocarpine in ALS patients elicited normal responses in both flow rate and bicarbonate concentration of saliva. It is concluded that the pancreatic and parotid deficiencies observed in ALS patients do not indicate primary disease of these exocrine glands. This interpretation is further emphasized by the results obtained by a sweat test, plasma osmolarity, and sialographic studies. The possibility that the gland impairments observed might be due to modifications of the neuroendocrine mechanisms regulating their secretory activity is suggested.

Adult↗

PubMedDate not supplied

Configurational and elemental odor mixture perception can arise from local inhibition.

Contrast enhancement via lateral inhibitory circuits is a common mechanism in sensory systems. We here employ a computational model to show that, in addition to shaping experimentally observed molecular receptive fields in the olfactory bulb, functionally lateral inhibitory circuits can also mediate the elemental and configurational properties of odor mixture perception. To the extent that odor perception can be predicted by slow-timescale neural activation patterns in the olfactory bulb, and to the extent that interglomerular inhibitory projections map onto a space of odorant similarity, the model shows that these inhibitory processes in the olfactory bulb suffice to generate the behaviorally observed inverse relationship between two odorants' perceptual similarities and the perceptual similarities between either of these same odorants and their binary mixture.

Action Potentials↗

PubMed1997

Auditory hallucinations and the temporal cortical response to speech in schizophrenia: a functional magnetic resonance imaging study.

OBJECTIVE: The authors explored whether abnormal functional lateralization of temporal cortical language areas in schizophrenia was associated with a predisposition to auditory hallucinations and whether the auditory hallucinatory state would reduce the temporal cortical response to external speech. METHOD: Functional magnetic resonance imaging was used to measure the blood-oxygenation-level-dependent signal induced by auditory perception of speech in three groups of male subjects: eight schizophrenic patients with a history of auditory hallucinations (trait-positive), none of whom was currently hallucinating; seven schizophrenic patients without such a history (trait-negative); and eight healthy volunteers. Seven schizophrenic patients were also examined while they were actually experiencing severe auditory verbal hallucinations and again after their hallucinations had diminished. RESULTS: Voxel-by-voxel comparison of the median power of subjects' responses to periodic external speech revealed that this measure was reduced in the left superior temporal gyrus but increased in the right middle temporal gyrus in the combined schizophrenic groups relative to the healthy comparison group. Comparison of the trait-positive and trait-negative patients revealed no clear difference in the power of temporal cortical activation. Comparison of patients when experiencing severe hallucinations and when hallucinations were mild revealed reduced responsivity of the temporal cortex, especially the right middle temporal gyrus, to external speech during the former state. CONCLUSIONS: These results suggest that schizophrenia is associated with a reduced left and increased right temporal cortical response to auditory perception of speech, with little distinction between patients who differ in their vulnerability to hallucinations. The auditory hallucinatory state is associated with reduced activity in temporal cortical regions that overlap with those that normally process external speech, possibly because of competition for common neurophysiological resources.

Adult↗

PubMedDate not supplied

Primary lymphedema precox of the penis and its surgical treatment: a case report.

Primary penile lymphedema occurs infrequently and is seen in conjunction with a similar process in the scrotum. The accepted form of treatment is surgery since conservative medical treatment is of little value. Different surgical techniques have been described, but no single procedure has emerged as the ideal treatment. Radical excision of all lymphedematous tissues and reconstruction using local penile flaps yield excellent functional and cosmetic results. We treated a 13-year-old boy with primary penile lymphedema precox using radical excision and reconstruction with local penile flaps. At follow-up two years later, functional and cosmetic results were satisfactory.

Adolescent↗

PubMed2006

[Diagnosis and treatment of cauda equina syndrome secondary to lumbar disc herniation].

OBJECTIVE: To discuss the diagnosis and treatment of cauda equina syndrome. METHODS: Thirty-four cases of cauda equina syndrome from 1993 to 2005 were analysed retrospectively. Its clinical representation, pathology character and clinical outcome were observed. RESULTS: At follow-ups of 3 to 102 months after the treatment (averagely 43 months), the muscle strength and function of the constrictor began to resume to different degrees. Muscle strength resumed gradually one week after the operation, resumed faster 3 months after the operation, and resumed completely more one year later. Function of the constrictor began to resume 3 days after the operation, and resumed mostly six months or so after the operation. Sense resumed slowly. CONCLUSION: Clinical outcome of cauda equina syndrome is good. Resumption after the operation obviously correlates to the time of operation. One week after the operation, the kinetic function resumes best, function of the constrictor resumes well and the sense function of the saddle area resumes not very well.

Adult↗

PubMed1992

[Laryngeal closure--a simple method and a reversible method for phonation preservation].

Patients with dysphagia due to a disorder in swallowing phase II are candidates for laryngeal closure operation. The operation prevents bolus drainage into the larynx and therefore permits oral feeding. Operative methods in general should be simple and reliable, and furthermore, with regards to this laryngeal closure procedure, they should preferably be reversible to maintain phonatory function, in the event that patients improve swallowing function later on. A laryngeal closure operation which satisfies both conditions has not been previously reported. We present two laryngeal closure operations. One is relatively simple and reliable but irreversible in terms of phonatory function. The other procedure requires more effort but is reversible and therefore allows for preservation of phonatory function. We performed one of these operations on two cases each and obtained good results. 1. Laryngeal closure at the vocal cords. (simple method) The frontal neck skin is incised vertically. The thyroid cartilage perichondrium is incised in the midline and retracted widely on both sides. Then the anterior thyroid lamina is removed at the crico-arytenoid joint. A control hole is opened into the laryngeal lumen by an incision made from the cricoarytenoid membrane to the anterior commissure. The larynx is cut horizontally from the anterior to posterior commissure between the upper and lower lips of the vocal cords. Finally the vocal cords are sutured at the top and bottom of the cut stump. 2. Closure at the false vocal cords. (reversible method for phonation preservation) After the vertical incision has been made, the laryngeal lumen is opened by laryngofissure.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1998

The Pristionchus HOX gene Ppa-lin-39 inhibits programmed cell death to specify the vulva equivalence group and is not required during vulval induction.

In the two nematode species Caenorhabditis elegans and Pristionchus pacificus the vulva equivalence group in the central body region is specified by the Hox gene lin-39. C. elegans lin-39 mutants are vulvaless and the vulval precursor cells fuse with the surrounding hypodermis, whereas in P. pacificus lin-39 mutants the vulval precursor cells die by apoptosis. Mechanistically, LIN-39 might inhibit non-vulval fate (cell fusion in C. elegans, apoptosis in P. pacificus), promote vulval fate or do both. To study the mechanism of lin-39 function, we isolated P. pacificus cell death mutants and identified mutations in ced-3. Surprisingly, P. pacificus ced-3; lin-39 double mutants form a functional vulva in the absence of LIN-39 activity. Thus, in P. pacificus lin-39 specifies the vulva equivalence group by inhibiting programmed cell death. Furthermore, these data reveal an important difference in a later function of lin-39 between the two species. In C. elegans, LIN-39 specifies vulval cell fates in response to inductive RAS signaling, and in P. pacificus LIN-39 is not required for vulval induction. Thus, the comparative analysis indicates that lin-39 has distinct functions in both species although the gene is acting in a homologous developmental system.

Animals↗

PubMed2004

Age, functional capacity, and health-related quality of life in patients with heart failure.

BACKGROUND: Although heart failure disproportionately affects older persons and is associated with significant physical disability, existing data on physical limitations and health-related quality of life (HRQL) derive largely from studies of younger subjects. We compared the relationship between functional limitation and HRQL between older and younger patients with heart failure. METHODS AND RESULTS: We evaluated 546 outpatients with heart failure enrolled in a multicenter prospective cohort study. At baseline and 6 +/- 2 weeks later, functional status was assessed by New York Heart Association (NYHA) classification and 6-minute walk testing. HRQL was measured with the Kansas City Cardiomyopathy Questionnaire (KCCQ). Comparing older (age >65 years, n = 218) and younger patients (n = 328), we assessed baseline HRQL across strata of functional status. In the 484 patients who completed follow-up (194 older and 290 younger patients), we also assessed the changes in HRQL associated with changes in functional status over time. At baseline, older patients had better HRQL than younger patients (mean KCCQ score 60 +/- 25 versus 54 +/- 28, P = .005) in spite of worse NYHA class (mean 2.54 versus 2.35, P < .001) and lower 6-minute walk distances (824 +/- 378 versus 1064 +/- 371 feet, P < .001). After multivariable adjustment including baseline NYHA class, older age was independently correlated with better HRQL (beta = +7.9 points, P < .001). At follow-up, older patients with a deterioration in NYHA class experienced marked declines in HRQL compared with younger patients (mean HRQL change of -14.4 points versus +0.3 points, respectively, P < .001). Analyses using 6-minute walk distance as the functional measure yielded similar results. CONCLUSIONS: Although older patients with heart failure have relatively good HRQL in spite of significant functional limitations, they are at risk for worsening HRQL with further decline in functional status. These results underscore the importance of treatments aimed at maintaining functional status in older persons with heart failure, including those with significant baseline functional limitations.

Age Factors↗