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PubMed1996

Motion sickness susceptibility to optokinetic rotation correlates to past history of motion sickness.

PURPOSE: This study investigated correlations between motion sickness susceptibility to a rotating optokinetic drum and past history of motion sickness. METHOD: There were 49 subjects who filled out a questionnaire on motion sickness history (MSH) who participated in the experiment. Each subject sat in an optokinetic drum for a 12-min baseline and a 12-min drum rotation period. Subjects' motion sickness symptoms (MSS) and electrogastrograms (EGG's) were measured. RESULTS: There were significant correlations between MSH scores and MSS scores during drum rotation (r = 0.5392, p < 0.001), and between MSH scores and EGG 4-9 cycles per minute (cpm) spectral intensity ratios between drum rotation and baseline periods (r = 0.5320, p < 0.001). Further analysis indicated that the mean MSS scores during the drum rotation period were 11.50 for the top 33% MSH scorers, 4.18 for the middle 34% MSH scorers, and 3.63 for the bottom 33% MSH scorers. The mean EGG 4-9 cpm spectral intensity ratios between drum rotation and baseline periods were 2.62 for the top 33% MSH scorers, 1.44 for the middle 34% MSH scorers, and 1.21 for the bottom 33% MSH scorers. CONCLUSION: These results indicated that past history of motion sickness correlates with severity of motion sickness provoked by optokinetic rotation.

Adult↗
PubMed1996

The severity of nauseogenic effect of cross-coupled rotation is proportional to gyroscopic angular acceleration.

METHOD AND RESULTS: Subjects underwent cross-coupled rotation of the head (i.e., Coriolis stimuli) during which the upper body was tilted from side to side during horizontal rotation of the whole body about the Earth-vertical axis. In Experiment 1, the angle between the two axes of cross-coupled rotation was changed to vary the magnitude of gyroscopic angular acceleration without wide variations in Coriolis linear acceleration. The severity of nausea evoked by cross-coupled rotation stimuli varied relative to the magnitude of gyroscopic angular acceleration. It is noteworthy that nausea was not evoked unless gyroscopic angular acceleration was generated, even though Coriolis linear acceleration was equally induced. In Experiment 2, subjects tilted the upper body with or without restriction of head movement to a vertical plane during Earth-vertical axis rotation of the body at various angular velocities. The severity of evoked nausea was in direct proportion to angular velocity of body rotation irrespective of the restriction. CONCLUSION: These results indicated that the severity of nauseogenic effect of cross-coupled rotation is directly proportional to gyroscopic angular acceleration.

Acceleration↗
PubMedDate not supplied

Visual-vestibular interaction during off-vertical axis rotation.

The aim of this study was to further define the eye movement response to combined visual and vestibular stimulation, especially during linear acceleration. Subjects included 15 asymptomatic healthy individuals (8 females and 7 males) between the ages of 20 and 31 years. Vestibular stimulation consisted of earth-vertical axis rotation and off-vertical axis rotation (OVAR). Visual stimuli consisted of projected vertical stripes that were rotated for optokinetic trials and stationary for visual augmentation trials. A small laser target (0.5 mW, 0.5 degree arc) that rotated with the subject was used for fixation trials. Eye movements were measured with electro-oculography. Results showed that visual-vestibular interaction during sinusoidal rotation was not affected by a 15 degree off-vertical tilt. Constant velocity OVAR induced a continuous nystagmus whose slow component velocity contained a nonzero baseline, that is, a bias, and a periodic fluctuation at the rotation frequency, that is, a modulation component. The modulation component during visual fixation was reduced as compared with that seen during rotation in the dark, but was not absent. Constant velocity OVAR in the presence of earth-fixed stripes induced a consistent sinusoidal modulation. Our results suggest that visual-vestibular interaction for otolith stimulation differs from visual-vestibular interaction for semicircular canal stimulation. The modulation component of the response to OVAR appears to be modified by visual stimulation to a lesser extent than other vestibular-induced eye movements and thus may reflect a more "direct" vestibulo-ocular response. The bias component of the response to OVAR can be substantially influenced by vision and thus may depend upon more "indirect" pathways.

Acceleration↗
PubMed1997

Triple innominate osteotomy and rotational acetabular osteotomy in the treatment of congenital hip dysplasia.

Congenital hip dysplasia is a developmental disease which predisposes patients to osteoarthritis of the hip. We compare the results and complications of triple innominate osteotomy and rotational acetabular osteotomy in the treatment of this disease. Between 1984 and 1992, 27 patients with 30 dysplastic hips received reconstructive procedures at National Taiwan University Hospital. Fourteen patients (16 hips) with a median age of 18 years were treated by triple innominate osteotomy. Nine of 16 hips had concomitant femoral osteotomy. Another 13 patients (14 hips) with a median age of 24 years were treated by rotational acetabular osteotomy. We compared the radiologic and functional results, complications and satisfaction of the patients in these two groups. Patients who underwent rotational osteotomy showed more correction in roof obliquity than patients who had triple innominate osteotomy. The functional results when evaluated by Harris scores, were better in patients who had triple innominate osteotomy than rotational osteotomy. Complications included one resubluxation of the hip in each group as well as one perforation of the hip joint and one pin break and nonunion at the osteotomy site in the rotational osteotomy group. Patients who had triple innominate osteotomy were more satisfied with the results. With proper selection of patients and accurate performance of the procedure, both triple innominate osteotomy and rotational osteotomy may be used effectively for the treatment of congenital hip dysplasia. However, in our study, patients who underwent rotational osteotomy had better anatomic correction, while those who underwent triple innominate osteotomy had better functional results.

Acetabulum↗
PubMed1997

Metabotropic glutamate agonist-induced rotation: a pharmacological, FOS immunohistochemical, and [14C]-2-deoxyglucose autoradiographic study.

Metabotropic glutamate receptors (mGluRs) are a major class of excitatory amino acid receptors. Eight mGluR subtypes, coupled to a variety of effector systems, have been cloned. These receptors have been classified into three groups based on amino acid sequence homology, effector systems, and pharmacological profile. Group I mGluRs increase phosphoinositide turnover, whereas groups II and III mGluRs are negatively coupled to adenylyl cyclase. The striatum possesses a high density of mGluR binding sites, and several mGluR mRNAs and proteins are expressed by striatal neurons. In rats, unilateral striatal injection of the nonsubtype selective mGluR agonist 1-aminocyclopentane-1S,3R-dicarboxylic acid (1S,3R-ACPD) results in contralateral rotation with delayed onset, thought to be secondary to an increase in dopamine release. We sought to determine the mGluR subtype(s) involved, the modulation of the rotation by other basal ganglia neurotransmitter systems, and the functional anatomy underlying the rotational behavior. The group I mGluR agonist 3,5-dihydroxyphenylglycine (DHPG) induced contralateral rotation in a dose-dependent manner, whereas group II and group III agonists were ineffective. Rotation induced by DHPG or 1S,3R-ACPD was attenuated by group I antagonists, but not by group II or group III antagonists. This suggests that the rotation is mediated by group I mGluRs. Rotation induced by DHPG or 1S,3R-ACPD was attenuated by pretreatment with antagonists at muscarinic cholinergic, adenosine A2, dopamine D2, or dopamine D1 receptors. Examination of FOS-like immunoreactivity after group I and group II mGluR agonist administration suggests increased activity in the striatopallidal pathway. However, [14C]-2-deoxyglucose uptake studies indicate increased activity in nuclei of the striatopallidal (indirect) pathway, particularly in the subthalamic nucleus, only after group I mGluR activation.

Animals↗
PubMed1998

Triplex ultrasound of vertebral artery flow during cervical rotation.

BACKGROUND: Reviewing the literature on vertebral artery flow during cervical rotation shows various results. Furthermore, most studies have investigated exclusively the effects of contralateral rotation employing less-than-optimal Doppler ultrasound technique. OBJECTIVE: The aim of this study was to use the latest advancement in Doppler ultrasound technology to investigate flow velocity in the vertebral artery during both ipsilateral and contralateral cervical rotation in normal subjects. DESIGN AND SETTING: A prospective, controlled study in a university hospital vascular laboratory. PARTICIPANTS: Twenty healthy university students. RESULTS: Peak flow velocity decreased significantly during contralateral rotation and increased significantly during ipsilateral rotation. The differences, however, were modest. We found no correlation between peak flow velocity and systolic blood pressure. CONCLUSION: With modern Doppler ultrasound technique, preventing some sources of error in measuring, our finding during contralateral rotation were in accordance with most previous studies showing a decrease in peak flow velocity. For the first time, however, we report an increased flow velocity in the vertebral artery during ipsilateral rotation.

Adult↗
PubMed1998

Mental rotation of objects versus hands: neural mechanisms revealed by positron emission tomography.

Twelve right-handed men participated in two mental rotation tasks as their regional cerebral blood flow (rCBF) was monitored using positron emission tomography. In one task, participants mentally rotated and compared figures composed of angular branching forms; in the other task, participants mentally rotated and compared drawings of human hands. In both cases, rCBF was compared with a baseline condition that used identical stimuli and required the same comparison, but in which rotation was not required. Mental rotation of branching objects engendered activation in the parietal lobe and Area 19. In contrast, mental rotation of hands engendered activation in the precentral gyrus (M1), superior and inferior parietal lobes, primary visual cortex, insula, and frontal Areas 6 and 9. The results suggest that at least two different mechanisms can be used in mental rotation, one mechanism that recruits processes that prepare motor movements and another mechanism that does not.

Adolescent↗
PubMedDate not supplied

Spatial updating during rotation: the role of vestibular information and mental activity.

The remarkable accuracy with which healthy subjects can monitor their orientation while walking in darkness has been attributed to a process whereby awareness of orientation is automatically updated by information derived from active locomotion. The aim of this study was, first, to determine the contribution of vestibular information to the perception of orientation without vision, by comparing the accuracy of judgments of orientation following passive (seated) rotation about an earth-vertical axis with those following active (locomotor) rotation. The second aim was to assess whether monitoring orientation is indeed automatic, or whether it requires some degree of mental effort. This was evaluated by assessing whether accuracy in monitoring multiple passive or active rotations was affected by asking subjects to perform a mental task (that is, counting backwards) during rotation. The results indicated that although reliance on the primarily vestibular information available during passive rotation enabled subjects to accurately monitor single turns of up to 180 degrees, subjects were able to judge orientation after multiple turns more accurately after active rotation than after passive rotation, owing to the additional sensorimotor feedback gained from active locomotion. Accuracy in judging orientation was substantially impaired by backwards counting during both passive and active locomotion. This finding confirms that monitoring orientation during multiple turns in darkness necessitates central processing and adds to the growing body of evidence for the influence of mental activity on the perception and control of orientation.

Adult↗
PubMed2026

Open repairs with biceps rerouting does not impact retears in large to massive rotator cuff tears compared to conventional open repair: a randomized clinical trial.

BACKGROUND: The treatment of large to massive rotator cuff tears leads to a high failure rate and several techniques have been proposed to improve these results. Rerouting the long head of the biceps tendon (LHBT) appears to be a biological reinforcement to increase tendon healing. Therefore, this study aimed to compare the clinical and radiological outcomes of open repair for large and massive rotator cuff tears reinforced with the LHBT to conventional open repair. METHODS: A prospective randomized study was conducted with patients diagnosed with large to massive rotator posterosuperior rotator cuff tear and intact LHBT, randomized into 2 groups: biceps rerouting and conventional open repair. The functional outcomes were assessed by the American Shoulder and Elbow Surgeon score, University of California at Los Angeles score, and SF-12 questionnaire preoperatively and at 6, 12, and 24 months postoperatively. Pain level was also assessed by the visual analog scale including the first day and 2 weeks postoperatively. Structural outcomes were rotator cuff and LHBT healing with magnetic resonance imaging and acromiohumeral distance (AHD) through radiography. RESULTS: We evaluated 58 patients, 29 in each group. At the end of the follow-up there were no statistically significant differences between groups in American Shoulder and Elbow Surgeon (76.1 vs. 80.4, P = .761), University of California at Los Angeles (27.1 vs. 29.1, P = .634), or visual analog scale scores (1.3 vs. 1.1, P = .781). Additionally, rotator cuff healing rates (48.3% vs. 44.8%, P = .402) and LHBT healing rates (79.3% vs. 82.7%, P = .738) were similar. AHD increased in both groups, with no significant difference in delta AHD (P = .513). Both groups showed significant clinical improvement over time in all evaluated outcomes (P < 0,01). No postoperative complications were reported. CONCLUSIONS: We could not identify an advantage of open repair with LHBT rerouting as reinforcement over conventional open repair. Nonetheless, all clinical scores improved at the end of the 24 months of follow-up in both groups.

Humans↗
PubMedDate not supplied

A biomechanical analysis of rotator cuff deficiency in a cadaveric model.

We conducted this cadaveric study to define a biomechanical rationale for rotator cuff function in several deficiency states. A dynamic shoulder testing apparatus was used to examine change in middle deltoid muscle force and humeral translation associated with simulated rotator cuff tendon paralyses and various sizes of rotator cuff tears. Supraspinatus paralysis resulted in a significant increase (101%) in the middle deltoid force required to initiate abduction. This increase diminished to only 12% for full glenohumeral abduction. The glenohumeral joint maintained ball-and-socket kinematics during glenohumeral abduction in the scapular plane with an intact rotator cuff. No significant alterations in humeral translation occurred with a simulated supraspinatus paralysis, nor with 1-, 3-, and 5-cm rotator cuff tears, provided the infraspinatus tendon was functional. Global tears resulted in an inability to elevate beyond 25 degrees of glenohumeral abduction despite a threefold increase in middle deltoid force. These results validated the importance of the supraspinatus tendon during the initiation of abduction. Glenohumeral joint motion was not affected when the "transverse force couple" (subscapularis, infraspinatus, and teres minor tendons) remained intact. Significant changes in glenohumeral joint motion occurred only if paralysis or anatomic deficiency violated this force couple. Finally, this model confirmed that rotator cuff disease treatment must address function in addition to anatomy.

Aged↗
PubMed2005

Rotator cuff repair in patients with rheumatoid arthritis.

BACKGROUND: Currently, there is very little information available regarding the results of rotator cuff repair in patients with rheumatoid arthritis. Therefore, we reviewed our experience to determine the results, the risk factors for an unsatisfactory outcome, and the rates of failure of this procedure. METHODS: We retrospectively reviewed the records of all patients with rheumatoid arthritis who had undergone repair of a rotator cuff tear at our institution from 1988 to 2002. Twenty-three shoulders in twenty-one patients were identified. The median duration of follow-up for the twenty shoulders that did not require revision surgery was 9.7 years. Nine shoulders had a partial-thickness tear, and fourteen had a full-thickness tear. The shoulders were assessed with regard to pain, functional outcome, and overall patient satisfaction. RESULTS: Patients with both partial and full-thickness rotator cuff tears had significant improvements in terms of overall pain (p < 0.05) and satisfaction (p < 0.05). Patients who had undergone repair of a partial-thickness tear had improved active elevation (from 155 degrees to 180 degrees; p = 0.03), whereas patients who had undergone repair of a full-thickness tear did not have improved elevation. Six of the fourteen shoulders with a full-thickness tear had an unsatisfactory result, whereas only two of the nine shoulders with a partial-thickness tear had an unsatisfactory result. CONCLUSIONS: Rotator cuff repair in patients with rheumatoid arthritis can be challenging. However, durable pain relief and patient satisfaction can be achieved. Functional gains should not be expected in patients with full-thickness rotator cuff tears. Repair of the rotator cuff in patients with rheumatoid arthritis can be undertaken when nonoperative measures for pain relief have failed.

Arthritis, Rheumatoid↗
PubMed1997

Rotator cuff pathology in athletes.

The rotator cuff is the primary dynamic stabiliser of the glenohumeral joint and is placed under significant stress during overhead and contact sports. Mechanisms of injury include repetitive microtrauma, usually seen in the athlete involved in overhand sports, and macrotrauma associated with contact sports. Rotator cuff injury and dysfunction in the overhand athlete may be classified based on aetiology as primary impingement, primary tensile overload, and secondary impingement and tensile overload resulting from glenohumeral instability. A thorough history and physical examination are paramount in the evaluation, classification and treatment planning of the athlete with rotator cuff pathology. Imaging studies are a helpful adjunct to the history and physical. Athletes with primary impingement are usually middle aged or older and often have chronic shoulder pain and sometimes weakness associated with overhand sporting activities. Night pain is typical of full thickness rotator cuff tears. Impingement signs are positive and strength of elevation and external rotation are often limited. They usually respond to a nonoperative rehabilitation programme centred on decreasing inflammation, restoring range of motion and strengthening the rotator cuff and scapular stabilisers. Depending on the degree of cuff pathology, acromioplasty, debridement of partial cuff tears, and repair of full thickness tears are usually successful in those who fail a rehabilitation programme. Overhand athletes with cuff pathology secondary to subtle anterior instability are usually young and complain of pain and decreased throwing velocity. Instability may be so subtle that it is only detectable through a positive relocation test on examination. The majority of these athletes do not have a Bankart lesion on magnetic resonance imaging or arthroscopic examination. Arthroscopic examination usually demonstrates anterior capsular laxity (positive 'drive-through' sign), as well as superior-posterior labral and cuff injury typical of internal impingement. If rehabilitation alone is not successful, a capsulolabral repair followed by rehabilitation may allow the athlete to return to their previous level of competition. The athlete with an acute episode of macrotrauma to the shoulder resulting in cuff pathology usually presents with pain, limited active elevation and a positive 'shrug sign'. Arthroscopy and debridement of thickened, inflamed or scarred subacromial bursa with cuff repair or debridement as indicated is usually successful in those who do not respond to a rehabilitation programme.

Arthroscopy↗
PubMed1999

Angular variances for internal bond rotations of side chains in GXG-based tripeptides derived from (13)C-NMR relaxation measurements: Implications to protein folding.

The study of backbone and side-chain internal motions in proteins and peptides is crucial to having a better understanding of protein/peptide "structure" and to characterizing unfolded and partially folded states of proteins and peptides. To achieve this, however, requires establishing a baseline for internal motions and motional restrictions for all residues in the fully, solvent-exposed "unfolded state." GXG-based tripeptides are the simpliest peptides where residue X is fully solvent exposed in the context of an actual peptide. In this study, a series of GXG-based tripeptides has been synthesized with X being varied to include all twenty common amino acid residues. Proton-coupled and -decoupled (13)C-nmr relaxation measurements have been performed on these twenty tripeptides and various motional models (Lipari-Szabo model free approach, rotational anisotropic diffusion, rotational fluctuations within a potential well, rotational jump model) have been used to analyze relaxation data for derivation of angular variances and motional correlation times for backbone and side-chain chi(1) and chi(2) bonds and methyl group rotations. At 298 K, backbone motional correlation times range from about 50 to 85 ps, whereas side-chain motional correlation times show a much broader spread from about 18 to 80 ps. Angular variances for backbone phi,psi bond rotations range from 11 degrees to 23 degrees and those for side chains vary from 5 degrees to 24 degrees for chi(1) bond rotations and from 5 degrees to 27 degrees for chi(2) bond rotations. Even in these peptide models of the "unfolded state," side-chain angular variances can be as restricted as those for backbone and beta-branched (valine, threonine, and isoleucine) and aromatic side chains display the most restricted motions probably due to steric hinderence with backbone atoms. Comparison with motional data on residues in partially folded, beta-sheet-forming peptides indicates that side-chain motions of at least hydrophobic residues are less restricted in the partially folded state, suggesting that an increase in side-chain conformational entropy may help drive early-stage protein folding. Copyright 1999 John Wiley & Sons, Inc.

Journal Article↗
PubMed2001

Color duplex sonographic findings in human vertebral arteries during cervical rotation.

PURPOSE: The aims of this study were to determine whether vertebral artery blood flow velocity changes during contralateral cervical rotation, to determine the extent of rotation necessary to affect the velocity, and to find direct evidence of stretching or compression of the vertebral arteries during cervical rotation. METHODS: Color duplex sonography was used to measure the blood flow velocities and diameters of the vertebral arteries in 20 patients. Measurements were taken with the patients' heads in the neutral position and at 10 degrees increments of contralateral neck rotation (determined using a cervical range of motion goniometer) to the end-range. RESULTS: The data showed no significant change in the mean blood flow velocity for the entire study population during cervical rotation. However, there were marked changes in the blood flow velocities in 7 vertebral arteries toward the end-range of rotation. No arteries displayed any evidence of major stretching of the arterial walls, although localized compression of 2 arteries was observed. CONCLUSIONS: The results of this study suggest that vertebral arteries are usually unaffected by contralateral cervical rotation and that Doppler sonography may provide an indirect assessment of mechanical stresses to the arterial wall.

Adult↗
PubMed2001

Effects of A-P translation and rotation on the wear of UHMWPE in a total knee joint simulator.

We developed a three-channel total knee joint simulator and studied the effect of tibial anterior-posterior translation and internal/external rotation on the wear of polyethylene tibial inserts in total knee replacements (Anatomic Graduated Component knees). The wear rate was the lowest in experiment (Exp.) 1, without translation and rotation [1.74 mg/million (mg/Mc) cycles]. In Exp. 2, with +/-5 degrees tibial rotation added, the wear rate increased to 10.6 mg/Mc. In Exp. 3, with rotation and -12 mm tibial translation added, the wear rate was 15.1 mg/Mc, whereas in Exp. 4, with rotation and +12 mm tibial translation, the wear rate was 18.7 mg/Mc. Internal/external rotation and anterior-posterior translation added a 6- to 11-fold increase in the wear rates of tibial knee inserts. The shapes of the tibial wear tracks were rectangular and the area of the track increased when rotation and translation were added.

Biomechanical Phenomena↗
PubMed2003

Timetable for intestinal rotation in staged human embryos and fetuses.

BACKGROUND: The existing data on intestinal rotation during human development are contradictory regarding the timing of major events, and as such an exact timetable for rotation of the intestine in humans is not yet available. METHODS: We studied the initial formation and rotation of the intestine by microdissection and histological observations in 72 human embryos and fetuses at two to 12 weeks postfertilization. The embryos were classified according to the Carnegie staging system. RESULTS: The primordium of the primitive gut was first observed as a yolk sac at stage 5. With the formation of the embryonic foldings, three divisions of the primitive gut (the foregut, midgut, and hindgut) were observed at stage 10. At stage 12, the primitive gut was located on the midline. At stage 15, a 90 degrees counterclockwise rotation of the intestine began. At stage 16, herniation of the intestine into the umbilical cord was not evident in observations of the external form or a transversely sectioned embryo, but was evident in a sagittally sectioned embryo. There was another 90 degrees counterclockwise rotation at stage 20. Reduction of the intestine was a rapid process, since it was still in the cord in fetuses of <40 mm crown-rump length (CRL), and was reduced above 40 mm in general during nine weeks of development. When the intestine returned to the abdominal cavity, the cecum was located in the right lower quadrant (the adult position). CONCLUSIONS: We have developed a standard timetable to describe the rotation of the intestine. The current results will be helpful in studies describing the pathogenesis of some developmental abnormalities in the intestine due to abnormal rotation.

Embryo, Mammalian↗
PubMed1993

Measurement of restricted rotational diffusion of fluorescent lipids in supported planar phospholipid monolayers using angle-dependent polarized fluorescence photobleaching recovery.

A theory describing the shapes of polarized fluorescence photobleaching recovery (PFPR) curves for a population of fluorophores undergoing restricted rotational diffusion in two-dimensional systems such as planar membranes has been developed. In this model, restricted rotational diffusion of the fluorophores is described by using reflective boundary conditions, in which the fluorophores are assumed to diffuse freely but only within an angular space of width 2 omega. The magnitude and apparent rate of the PFPR postbleach fluorescence curves are a function of both omega and the angle between the bleaching and observation beam polarizations psi. It is shown that estimates of the degree of rotational restriction omega may be obtained from changes in the psi-dependent postbleach fluorescence intensities. Using angle-dependent PFPR, slow rotational reorientations of the fluorescent lipid analogue 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine in distearoylphosphatidylcholine Langmuir-Blodgett monolayers deposited on octadecyltrichlorosilane-treated fused quartz were measured. As theoretically predicted for a rotationally restricted fluorophore population, both the initial F psi (0) and final F psi (infinity) postbleach fluorescence intensities varied as a function of psi, and no measurable change in the postbleach fluorescence intensities was observed for psi = 45 degrees. Using the theory for restricted rotational motion, the psi-dependent variations of the final fluorescence intensities F psi (infinity) obtained at two bleaching intensities gave an average apparent omega approximately 52 degrees. However, to adequately fit the F psi (0) data, inclusion of the theoretical effects of rapid (faster than the duration of the photobleaching pulse) fluorophore dynamics was also required. Best fits of the F psi (0) and F psi (infinity) data were obtained when the fluorophores were assumed to rapidly wobble within a cone of semiangle delta approximately 30 degrees-50 degrees while slowly rotating within an angular space defined by semiangle omega approximately 35 degrees-60 degrees. Subsequent analysis of the time- and psi-dependent changes in the post-bleach fluorescence curves F psi (t) gave apparent diffusion coefficients ranging from D approximately 10(-3) s-1 to 4 x 10(-2) s-1.

Carbocyanines↗
PubMed2002

The effects of age and sex on mental rotation performance, verbal performance, and brain electrical activity.

This study examined the effects of age and sex on mental rotation performance, verbal performance, and brain-wave activity. Thirty-two 8-year-olds (16 boys) and 32 college students (16 men) had EEG recorded at baseline and while performing four computerized tasks: a two-dimensional (2D) gingerbread man mental rotation, a 2D alphanumeric mental rotation, of three-dimensional (3D) basketball player mental rotation, and lexical decision making. Additionally, participants completed a paper- and pencil water level task and an oral verbal fluency task. On the 2D alphanumeric and 3D basketball player mental rotation tasks, men performed better than boys, but the performance of women and girls did not differ. On the water level task, men performed better than women whereas there was no difference between boys and girls. No sex differences were found on the 2D gingerbread man mental rotation, lexical decision-making, and verbal fluency tasks. EEG analyses indicated that men exhibited left posterior temporal activation during the 2D alphanumeric task and that men and boys both exhibited greater left parietal activation than women and girls during the 2D gingerbread man task. On the 3D basketball player mental rotation task, all participants exhibited greater activation of the right parietal area than the left parietal area. These data give insight into the brain activity and cognitive development changes that occur between childhood and adulthood.

Adult↗