No abstract available.
Functional Laterality*

Our survival and wellness require a balance between optimism and pessimism. Undue pessimism makes life miserable; however, excessive optimism can lead to dangerously risky behaviors. A review and synthesis of the literature on the neurophysiology subserving these two worldviews suggests that optimism and pessimism are differentially associated with the two cerebral hemispheres. High self-esteem, a cheerful attitude that tends to look at the positive aspects of a given situation, as well as an optimistic belief in a bright future are associated with physiological activity in the left-hemisphere (LH). In contrast, a gloomy viewpoint, an inclination to focus on the negative part and exaggerate its significance, low self-esteem as well as a pessimistic view on what the future holds are interlinked with neurophysiological processes in the right-hemisphere (RH). This hemispheric asymmetry in mediating optimistic and pessimistic outlooks is rooted in several biological and functional differences between the two hemispheres. The RH mediation of a watchful and inhibitive mode weaves a sense of insecurity that generates and supports pessimistic thought patterns. Conversely, the LH mediation of an active mode and the positive feedback it receives through its motor dexterity breed a sense of confidence in one's ability to manage life's challenges, and optimism about the future.
Cerebrum ; Depression ; Functional Laterality ; Negotiating ; Neurophysiology

BACKGROUNDS: Gamma band oscillatory activity is considered to be related to congnitive functions and illustrates that the concept of event-related oscillations bridges the gap between single neurons and neural assemblies. An event-related gamma oscillation is the time - locked responses of specific frequency, and can be identified by computing the amplitude frequency characteristics of the averaged event-related potentials(ERPs) after stimulation. OBJECTIVES: We purposed to present experimental paradigm to investigate @-band oscillation activities from the recording of ERPs by using auditory oddball paradigm and investigate the difference of @-band activity between schizophrenia and normal controls. METHODS: The ERPs resulting from auditory stimuli with oddball paradigm in a group of schizophrenics(n=11) and also a group of age-, sex- and handedness matched normal controls, were recorded by 128 channel EEG. The @-band oscillatory activities were calculated by using time-frequency wavelet decomposition of the signal between 20 and 80Hz. The @-band oscillatory activities of both groups were compared by t-test. RESULTS: The @-band oscillatory of the leads Fz,Gz and Pz of both groups were represented well in the time - frequency maps. Significant increases of the @-band activity in normal controls compared with schizophrenics were observed around 160 msec. 350msec. and 800 msec after stimulation. CONCLUSIONS: Our results suggested that the increment in @-band oscillatory activity during cognitive operations and decreased @-band activity in schizophrenics may be associated with the cognitive dysfunctions and the pathophyiology of the schizophrenia.
Electroencephalography ; Evoked Potentials* ; Functional Laterality ; Neurons ; Schizophrenia

BACKGROUND AND PURPOSE: The most remarkable behavioral asymmetry is handedness. The preferred hand often has better performance, motor strength, nonpreferred hand. However, whether these components are associated with skill learning is not clear. METHODS: We evaluated healthy right-handers by setting a series of motor-performance tasks including skill learning, grip strength, and speed. RESULTS: The preferred hand showed better skill performance and learning rate. However, the degree of the right-left difference in grip strength or speed difference did not correlate with the asymmetry in skill-learning rate. Therefore, although the preferred hand exhibits a better skill-learning capacity than the nonpreferred hand, asymmetry in skill learning cannot be explained by motor strength or speed. CONCLUSIONS: Our findings suggest that better skill performance of the right hand in right-handers cannot be attributed to the degree of hand preference score, strength, or motor speed.
Functional Laterality* ; Hand ; Hand Strength ; Learning* ; Motor Skills*

The present study compared the actigraphic indices between both wrist actigraphies (WATGs), and the sleep estimates between each WATG and nocturnal polysomnography (NPSG) to assess their differences and consistencies. We studied 22 right-handed subjects (mean age 43.9+/-13.3 years, M:F=14:8) with untreated primary sleep disorders (primary insomnia=8, simple snorer=2, obstructive sleep apnea=12) undergone by overnight both WATGs and NPSG, simultaneously. Comparison and correlation were analyzed between right and left wrist actigraphic data. In the sleep estimates of both WATGs and NPSG, each WATG was compared and correlated with NPSG in sleep period time (SPT), total sleep time (TST), sleep latency (SL), sleep efficiency (SE) and wake time (WT). Sleep indices between both WATGs showed significant positive correlations with no correlations in SL and fragmentation index (FI). There were no differences in sleep indices between both WATGs. SPTs of both WATGs, SL of left WATG, and TST of right WATG showed positively significant correlations, and SE of right WATG did negatively significant correlation in sleep indices between each WATG and NPSG. As each WATG was compared to PSG, SPTs of both WATGs and WT of right WATG were decreased, and TST and SE of right WATG and SL of left WATG were increased. Inconsistent SL and FI between both WATGs indicate that the activities between both WATGs can differentially happen during wake or arousal. Inconsistent sleep estimates between each WATG and NPSG may indicate the limited usefulness in measuring and analyzing one-night sleep by using WATG.
Arousal ; Functional Laterality ; Polysomnography* ; Sleep Wake Disorders ; Wrist*

OBJECTIVE: To explore the relationship between a number of clinically relevant variables and sonographic imaging data in respect to the level of impairment experienced in the affected and unaffected shoulders of hemiplegic stroke patients. METHOD: Fifty-one hemiplegic stroke patients (32 males, 19 females; 29 right-sided hemiplegics, 22 left-sided hemiplegics) participated in this study. A musculoskeletal radiologist conducted a sonographic exam on both the affected and unaffected shoulders of all patients and two physicians classified the severity of the injury on a six-point rating scale. Clinical variables including age, sex, duration of injury, spasticity and muscle power of the hemiplegic side, and level of functional activity of the shoulder were assessed. RESULTS: The sonographic rating scores of hemiplegic shoulders were positively correlated with age (p<0.01) and negatively correlated with level of muscle spasticity (p<0.05). The sonographic rating scores of unaffected shoulders were positively correlated with duration of injury (p<0.01). Affected shoulders received sonographic rating scores that reflected significantly more impairment than those of unaffected shoulders (p<0.001), and pre-morbid handedness did not affect the relationship between impairment rating and shoulder injury status. CONCLUSION: Hemiplegic stroke influences not only affected shoulders, but also unaffected sides. Proper management of spasticity, enhancement of motor recovery, and avoidance of unaffected shoulder overuse should be considered to prevent shoulder problems following strokes which result in hemiplegia.
Functional Laterality ; Hemiplegia ; Humans ; Male ; Muscle Spasticity ; Muscles ; Shoulder ; Stroke

OBJECTIVE: Schneiderian first-rank symptoms (FRS) and abnormal EEG gamma activity in schizophrenia have been reported independently to have a neurodevelopmental basis. We aimed to investigate spontaneous gamma power in two groups of first episode schizophrenia patients (those who experience FRS and those who do not). METHODS: A comparative hospital based study having 37neuroleptic naive male patients with schizophrenia divided into two groups-FRS(+) and FRS(-) groups based on the presence of FRS. Thirty age, sex, education and handedness matched individuals served as controls (N). All participants underwent a 192-channel resting Electroencephalography (EEG) recording. Gamma spectral power was calculated for low- (30-50 Hz) and high-gamma 1 & 2 (51-70 and 71-100 Hz) bands. Spectral power was compared between three groups using MANOVA and supplementary one-way ANOVA with Bonferroni test controlling for multiple comparisons. Linear regression was used to identifying predictor variables for FRS. Pearson correlation coefficient was computed between spectral power parameters and various clinical variables. RESULTS: Significantly higher high gamma band-1 power was observed over right frontal (p<0.05), parietal (p<0.05) and temporal (p<0.05) regions in FRS(+) than FRS(-) group and normal controls. Right parietal high gamma-1 power and paranoid cluster on PANSS significantly predicted number of FRS in total schizophrenia patients; paranoid cluster on PANSS showed significant correlation with number of FRS in FRS(+) group. CONCLUSION: Findings of our study add to the evidence that areas contained within the hetero modal association cortex are associated with FRS. The study findings also strengthen the neurodevelopmental basis of FRS in schizophrenia.
Education ; Electroencephalography* ; Functional Laterality ; Humans ; Linear Models ; Male ; Rabeprazole ; Schizophrenia*

Mirror writing is the simultaneous process of reversing individual letters and composing word strings in the reverse direction. This phenomenon appears rarely only after brain damage. We present the case of a 65-year-old, right-handed man with mirror writing following a left temporo-parietal lobe infarction. He preferred to write in the mirror direction with his left hand, but he did not show any visual-spatial disturbance and allochria. We think that damage to the dominant writing program of the brain, releases the normally suppressed contralesional writing program and this uninhibited program induces the mirror writing.
Aged ; Brain ; Functional Laterality* ; Hand* ; Humans ; Infarction* ; Writing

Left handedness is known to be related with inheritance and is different from right handedness in brain development and various aspects of perceptive and cognitive performance. Fingerprints are also related with inheritance and do not change for the whole life. In addition, individuals have different fingerprints. The aim of the present study was to identify genetic correlation between fingerprints and handedness by examining how different fingerprints are between left handers and right handers. The study group to imprint fingerprints was composed of 55 left handers and 144 right handers of 1063 college students. The reliability of handedness assessment tool was Cronbach's alpha=0.948. The imprinted fingerprints were classified by fingerprint type (arch, radial loop, ulnar loop, whorl). Finger ridges and triradii in fingerprints were also counted. We performed frequency analysis, reliability analysis, cross-tabs analysis, chi-square test, independent t-test, paired t-test by SPSS win 15.0 for the data. The left handed males and females exhibited more arch types than the right handers and less whorl types than the right handers. The left handers in both hands exhibited more arch and ulnar loop types than the right handers and less whorl and radial loop types than the right handers. In the left hand, the 3rd (p<0.05), 4th (p<0.05), and 5th (p<0.01) fingerprints of the left handers were different from those of the right handers. The finger ridge counts of left handers were significantly less than those of the right handers in the 2nd and 3rd fingers of the left hand, and in the 3rd and 4th fingers in the right hand. The triradii counts of left handers were significantly less than those of right handers (p<0.05) in the 3rd, 4th, and 5th finger of the left and right hand. Total triradii counts of left handers were also significantly less than those of right handers (p<0.05). These results demonstrate that fingerprint type, finger ridge and triradius counts of the left handers are different from those of the right handers, and fingerprints may reflect genetic tendency for handedness.
Brain ; Dermatoglyphics ; Female ; Fingers ; Functional Laterality ; Hand ; Humans ; Male ; Wills

Objective: To determine the relationship of the surgeon handedness and operative site laterality on operative duration and hearing improvement in otologic surgery, and to further explore whether this relationship may be related to surgeon experience. Methods: Design: Retrospective Cohort Setting: Tertiary Private Teaching Hospital Participants: Seventy-three (73) patients aged 18 to 65 years old who underwent primary ear surgery under general anesthesia between January 2016 and December 2019 were retrospectively divided into two groups: 39 contralateral and 34 ipsilateral. The operative durations and hearing improvements were compared using independent t-tests, with consideration of surgeon experience in years further stratifying patients. Results: There was no significant difference in operative duration, t(71) = 1.14, p = .26, between the contralateral (M = 281.95 minutes, SD = 71.82) and ipsilateral (M = 261.15, SD = 79.26) groups. This same pattern was more pronounced among surgeons with 10+ years of experience although there was also no significant difference in operative time, t(33) = 1.31, p = .19 for both ipsilateral and contralateral surgeries There was no statistically significant difference, t(36) = -0.72, p = .47, in overall mean hearing gain among patients in the contralateral (M = +2.22 dB, SD = 10.54) and ipsilateral (M = +5.12 dB, SD = 14.26) groups. Although the difference was also not statistically significant, t(16) = -1.94, p = .07 for contralateral (M = 0.00, SD = 5.43) and ipsilateral (M = +7.95 dB, SD = 11.52) procedures performed by surgeons with experience of 10 years or more, a mean hearing gain of +7 dB in the ipsilateral group compared to 0 dB in the contralateral group was notable. Conclusion: This study did not prove that regardless of surgeon experience, right-handed surgeons operating on the right ear and left-handed surgeons operating on the left ear have better ear surgery outcomes of operative duration and hearing improvement compared to right- handed surgeons operating on the left ear and left-handed surgeons operating on the right ear. Future studies on larger samples with more complete data may yet demonstrate this effect.
Functional Laterality ; otologic surgical procedures ; hearing ; operative time