强迫症患者言语流畅性任务脑激活时间特征的近红外光谱成像研究

目的:探讨强迫症患者言语流畅性任务(VFT)下前额叶及颞叶激活的时间特征。方法:选取70例符合DSM-IV强迫症诊断标准的患者和70例正常对照,应用52通道的近红外光谱成像技术(NIRS)测评完成VFT时前额叶及颞叶血流的变化。比较两组完成任务时氧合血红蛋白(oxy-Hb)、脱氧血红蛋白(deoxy-Hb)及总血红蛋白(total-Hb)浓度达峰时间的差异。结果:与正常对照组相比,强迫症患者52个通道oxy-Hb、deoxy-Hb和total-Hb浓度的平均达峰时间明显延迟[(61±12)s vs.(52±11)s,(64±10)s vs.(58±10)s,(59±13)s vs.(51±13)s,均P<0.01]。强迫症组oxy-Hb和total-Hb在眶额叶、额极、前额下回、颞中回及颞上回等脑区达峰时间明显延迟(均P<0.05,FDR校正)。结论:强迫症患者执行言语流畅性任务时前额叶及颞叶皮质激活可能有延迟。     

The relationship of categorical and phonological verbal fluency to negative schizotypy and social functioning in a non-clinical sample

Introduction: Research suggests that levels of schizotypy are related to cognitive and social functioning, with negative schizotypy being particularly related to deficits in verbal fluency (VF) and distinct social skills. Considering the possibility that different VF tasks may involve both shared and unique underlying processes, this study sought to examine the separate contributions of categorical and phonological forms of VF to social functioning in those with varying levels of negative schizotypy.

Methods: Face-to-face interviews were conducted in which 228 college students completed VF tasks, the SPQ-BR, and a social functioning questionnaire.

Results: Both phonological and categorical VF were inversely related to levels of negative schizotypy and inversely related to several social functioning domains. High and low levels of negative schizotypy groups were significantly different on elements of social engagement and interpersonal behaviour. In two instances, phonological VF appeared to moderate the relationships between negative schizotypy and specific elements of social functioning.

Conclusions: These findings support a general link between verbal processing and social functioning among those with greater negative schizotypy. Possible avenues of future research are discussed.     

Asymmetry of prefrontal cortex activities and catechol-O-methyltransferase Val158Met genotype in patients with panic disorder during a verbal fluency task: Near-infrared spectroscopy study

We examined the relationship between the catechol-O-methyltransferase (COMT) Val158Met genotype and frontal lobe function by using multi-channel near-infrared spectroscopy (NIRS). The present study investigated oxygenated ([oxy-Hb]) and deoxygenated ([deoxy-Hb]) hemoglobin concentration changes during the performance of a verbal fluency task in the frontal region of 71 patients with panic disorder (PD). The activation of [oxy-Hb] on the right lateral prefrontal cortex was observed in the Met/Met genotype of the COMT gene polymorphism of PD patient groups in the analysis of NIRS, which seems to be related to the autonomic dysfunction in the pathogenesis of PD.     

Influence of muscle activity on brain oxygenation during verbal fluency assessed with functional near-infrared spectroscopy

A large part of the literature of functional near-infrared spectroscopy (fNIRS) deals with overt verbal fluency. It has been claimed that fNIRS has a low susceptibility to movement related artefacts as, for example, associated with overt speech. However, so far, no study has investigated this assumption in an experimental design. Therefore, we examined a group of 16 healthy subjects during performance of two verbal fluency tasks (experiment 1: phonological fluency; experiment 2: semantical fluency, paced answers, pronouncing vs. writing). We measured changes of oxygenated (O₂Hb) and deoxygenated haemoglobin (HHb) over fronto-temporal (brain) areas via fNIRS, while temporalis muscle activity was simultaneously assessed by means of electromyography (EMG). Statistical analyses indicated comparable word production, higher increases of O₂Hb and higher decreases of HHb over fronto-temporal areas during word fluency in contrast to the control task weekday reciting. This fNIRS pattern indicates fluency related activation and was found for pronouncing and for writing in both experiments. Regarding the EMG data, fluency related activity was only found for pronouncing, not for writing. Thus, muscle activity cannot account for fluency related fNIRS activity during writing. Additionally, correlation analyses showed no systematic associations of fNIRS and EMG signals. In conclusion, we found arguments that fNIRS actually allows for the measurement of brain activity over fronto-temporal areas during verbal fluency. Nonetheless, further studies should evaluate more direct associations between fNIRS and EMG signals by specific experimental manipulations and data analysing approaches that allow dealing fNIRS and EMG raw data simultaneously.     

Effect of a physical barrier on response perseveration in hippocampal lesioned rats

Hippocampal lesioned and sham operated rats were required to relearn entry into a previously learned reinforced side arm in a T-maze from a new starting position 180 degrees from the original location. Half of each operated group were allowed free access while the other half had to open clear plastic doors to gain entry into the side arms. Only those hippocampal lesioned rats allowed free access to the side arms failed to relearn the entry response in fewer errors or with significant slower running speed than in the initial task. Both sham operated subgroups and the obstructed hippocampal lesioned group of rats learned the second task in fewer errors and displayed running speed disruption. The results were discussed in terms of a deficit of internal inhibition due to the limbic damage.     

Action-selection perseveration in young children: Advances of a dynamic model

This study presents an empirical test and dynamic model of perseverative limb selection in children of 14-, 24-, and 36-months old (N = 66 in total). In the experiment, children repeatedly grasped a spoon with a single hand. In two separate conditions, the spoon was presented either four times on their right side or four times on their left side. In both conditions, following this training, the spoon was presented on midline for two more trials. This setup enabled us to determine whether children's limb selection was influenced by their prior choices in the task (i.e., perseveration). Individual children's handedness was determined in a third condition consisting of nine object presentations (laterally or on midline). A dynamic model for limb selection is presented combining external input, motor memory, and preferences. The model was used to simulate the experiment and reproduced the results, including the age-related changes.     

Crossed cerebral lateralization for verbal and visuo-spatial function in a pair of handedness discordant monozygotic twins: MRI and fMRI brain imaging

To examine the nature of hemispheric lateralization for neural processes underlying verbal fluency and visuo-spatial attention, we investigated a single pair of handedness discordant monozygotic (MzHd) twins. Imaging of the brain was undertaken using magnetic resonance imaging (MRI) and functional magnetic resonance imaging (fMRI) in combination with manual performance tasks. The twins were discordant for MRI anatomical asymmetries of the pars triangularis and planum temporale, whose asymmetry was consistent with verbal laterality on fMRI. Thus, the right-handed twin had left lateralized verbal with right lateralized visuo-spatial attention, while the left-handed twin had right lateralized verbal with left lateralized visuo-spatial activation; these data lend further support for to the conclusions of Sommer et al.     

Comparable fMRI activity with differential behavioural performance on mental rotation and overt verbal fluency tasks in healthy men and women

To explicate the neural correlates of sex differences in visuospatial and verbal fluency tasks, we examined behavioural performance and blood-oxygenation-level-dependent (BOLD) regional brain activity, using functional magnetic resonance imaging, during a three-dimensional (3D) mental rotation task and a compressed sequence overt verbal fluency task in a group of healthy men (n=9) and women (n=10; tested during the low-oestrogen phase of the menstrual cycle). Men outperformed women on the mental rotation task, and women outperformed men on the verbal fluency task. For the mental rotation task, men and women activated areas in the right superior parietal lobe and the bilateral middle occipital gyrus in association with the rotation condition. In addition, men activated the left middle temporal gyrus and the right angular gyrus. For verbal fluency, men activated areas in the bilateral superior frontal gyrus, right cingulate gyrus, left precentral gyrus, left medial frontal gyrus, left inferior frontal gyrus, thalamus, left parahippocampal gyrus and bilateral lingual gyrus, and women activated areas in the bilateral inferior frontal gyrus and left caudate. Despite observing task related activation in the hypothesised areas in men and women, no areas significantly differentiated the two sexes. Our results demonstrate comparable brain activation in men and women in association with mental rotation and verbal fluency function with differential performance, and provide support for sex differences in brain–behaviour relationships.     

Sequential effects on P3 in a counting task: a partial replication

High and low tones were presented in random order, and the high tones had to be counted. It was intended to replicate the sequential effects on P3 reported by Squires et al. (1976, 1977) and to test by means of an ANOVA approach how each one of the preceding four tones contributes to these sequential effects. However, results deviated from those studies: (1) P3s were generally somewhat larger with target tones than with nontargets; (2) Squires et al.'s (1976, 1977) sequential effects were replicated for nontargets, but were more or less reversed for targets. The preceding sequence was found also to exert influence on prestimulus baselines, N1, and EOG. It is suggested that target effects constitute the rule rather than the exception and that sequential effects on P3 may be altered by subtle differences of subjects' sets, similarly to sequential effects on choice reaction times.     

Monitoring force errors: medial-frontal negativity in a unimanual force-production task

The effects of force production on medial-frontal negativity (MFN), reflecting the activity of an internal action-monitoring system, were investigated in a force-production task. A precue indicated a low or high force before a stimulus signaled the execution of the same or opposite force. An incorrectly exerted force was assumed to involve an error of force selection if the opposite force was required (invalid precue), and an error of force execution if the same force was required (valid precue). The task was repeated to examine any improvements in monitoring sensitivity. No force-related effects were observed on MFN amplitude. Although performance improved, there was no evidence of a force-error sensitive monitoring system. As the MFN and motor activity were affected by the precue invalidity regardless of the response outcome, the MFN might reflect the activity of a general action-evaluation system that is indirectly related to motor activation.     

Effects of cognitive behavioural therapy on verbal learning and memory in major depression: Results of a randomized controlled trial

Major depression (MD) is often accompanied by deficits in cognitive functioning. Cognitive behavioural therapy (CBT) has beneficial effects on MD. The aim of this study was to examine whether CBT affects verbal learning and memory in patients with MD and whether CBT that emphasizes exercise during behavioural activation has additional effects on verbal performance. Ninety‐eight patients with MD were randomly assigned to CBT emphasizing either exercise during behavioural activation (CBT‐E) or CBT emphasizing pleasurable low‐energy activities (CBT‐C). A passive waiting list control group was also involved (WL). Thirty nondepressed age‐ and sex‐matched controls were included to examine potential verbal learning and memory alterations in MD at baseline. Neuropsychological measures were assessed at baseline and after 16 weeks of CBT and waiting time, respectively. Patients with MD demonstrated worse cognitive performance than healthy controls in verbal learning, recognition, and memory at baseline. After treatment, we found no improvements concerning verbal learning and memory performance compared with WL, with the exception of recognition memory. No differences were found between CBT conditions. Psychological treatments such as CBT seem to have limited influence on memory functions. Concerning recognition memory, our results contradict, in part, previous assumptions that cognitive impairments persists despite depressive symptom reduction.     

Inhibitory motor control in apneic and insomniac patients: a stop task study

The aim of this study was to assess with a stop task the inhibitory motor control efficiency--a major component of executive control functions--in patients suffering from sleep disorders. Twenty-two patients with untreated obstructive sleep apnea syndrome (OSAS) (mean age 46 +/- 9 years; mean apnea-hypopnea index, AHI = 30 +/- 20) and 13 patients with psychophysiological insomnia (mean age 47 +/- 12 years) were compared with individually matched healthy controls. Sleep disturbances in the patient populations were clinically and polysomnographically diagnosed. The stop task has a frequent visual 'Go' stimulus to set up a response tendency and a less frequent auditory 'Stop' signal to withhold the planned or prepotent response. The stop signal reaction time (SSRT) reflects the time to internally suppress the ongoing response. SSRT was slower for the apneic patients than for their respective controls (248 +/- 107 versus 171 +/- 115 ms, anova, P < 0.05) but not for the insomniac patients compared with their controls (235 +/- 112 versus 194 +/- 109 ms, NS). Moreover, in apneic patients, slower SSRT was associated with lower nocturnal oxygen saturation (r = -0.477, P < 0.05). By contrast, neither apneics nor insomniacs differed from their matched controls for reaction times on Go trials. To conclude, unlike insomniacs, OSAS patients present an impaired inhibitory motor control, an executive function which is required in many common everyday life situations. Inhibitory motor control relies on the integrity of the inferior prefrontal cortex, which could be affected by nocturnal oxyhemoglobin desaturation in apneic patients.     

Action monitoring in motor control: ERPs following selection and execution errors in a force production task

Action monitoring has been studied in many tasks by means of measuring the error-related negativity (Ne/ERN), but never in a motor control task requiring precise force production. Errors in discrete choice reaction tasks are the result of incorrect selections, but errors in force production can also arise from incorrect executions. ERPs were obtained while participants produced low or high isometric forces with their left or right hand. As expected, incorrect choices of hand elicited an Ne/ERN. Interestingly, Ne/ERNs were also present in the less discrete selection error of an incorrect choice of force, but only when erroneously a low instead of a high force was chosen. In both force ranges, no Ne/ERNs were found after errors in execution. These errors showed a large positivity in feedback ERPs and, similar to correct responses, a prolonged negativity in response ERPs. We propose that, compared to selection errors, the time uncertainty aspects of execution errors and the resulting changing response representations prohibit error detection by the internal monitoring system responsible for generating the Ne/ERN.     

The effect of self-monitoring on Wisconsin Card Sorting Test performance in euthymic patients with bipolar disorder: a pilot study

Objectives: Euthymic patients with bipolar disorder (BD) show executive impairment. Assisting cognitive function with non-pharmacological strategies has not been widely explored in BD. In schizophrenia, concomitant verbalisation (self-monitoring) during executive tests improved performance. The present pilot study assesses the effects of self-monitoring whilst completing the Wisconsin Card Sorting Test (WCST) in BD patients.

Methods: Thirty-six euthymic BD patients and 42 healthy controls participated. Twenty patients with BD and 20 controls received standard administration and 16 patients and 22 controls used self-monitoring during the test.

Results: ANCOVA revealed a significant “group by administration” interaction. Patients who received the standard administration were significantly worse than healthy controls (trials administered: p?=?.012, η _p ²?=?0.17; trials to first category: p?=?.046, η _p ²?=?0.11; failure to maintain set: p?=?.003, η _p ²?=?0.23). BD patients who self-monitored performed significantly better than patients receiving the standard administration (trials to first category: p?=?.020, η _p ²?=?0.17) and showed no significant differences in performance compared to controls.

Conclusion: Self-monitoring deserves further investigation as a tool that may be helpful for patients with BD. Further exploration of the utility, generalisability, and stability of the effects of self-monitoring is needed.     

Elevated sulfatide excretion in heterozygotes of metachromatic leukodystrophy: Dependence on reduction of arylsulfatase a activity

Sulfatide excretion in urine and arylsulfatase A (ASA) activity in leukocytes were determined in 10 homozygotes of metachromatic leukodystrophy (MLD), 7 obligate and 5 facultative MLD heterozygotes, 6 low ASA subjects (not related to MLD homozygotes), and in 9 controls. As compared to controls (sulfatides: 0–2 nmol/mg lipid; ASA: 101–287 nmol p-nitro-catechol/mg protein/hr), MLD homozygotes displayed highly increased sulfatide excretions (27–280 nmol) and low residual ASA activities (0–13 nmol). Of 12 MLD heterozygotes (ASA: 18–87 nmol) 10 showed increased sulfatides (3–24 nmol). All heterozygotes with ASA activity <60 nmol (n = 8) had elevated sulfatide excretions (4–24 nmol). Thus, reduction of ASA activity below 40% of the mean value of controls seems to be the critical threshold for elevated sulfatide excretion in MLD heterozygotes. The low ASA subjects (ASA in the heterozygote range) excreted sulfatides in the control range, even those with ASA activities <60 nmoles (n = 3; including a definite homozygote for ASA-pseudodeficiency; ASA: 25 nmol). Statistical evaluation of sulfatide excretion and ASA activity in all subjects (n = 37) revealed a significant inverse relation (Spearman rank correlation; R = 0.8278, P< 0.001). The finding of elevated sulfatide excretion in certain MLD heterozygotes might point to increase of sulfatides also in the nervous system. © Wiley-Liss, Inc.     

A new grading system for female sexual dysfunction based on the female sexual function index in Egyptian women: a cross-sectional study

ObjectiveTo provide a grading system that accurately reflects the grades of female sexual dysfunction (FSD) severity.Patients and methodsA cross-sectional study was conducted in Assiut University Hospital. It included 500 women who answered the Arabic version of the Female Sexual Function Index (FSFI) after getting their consent. A gradient of FSD severity was created, classifying FSD into five grades: severe, moderate, mild to moderate, mild, and no FSD.ResultsAccording to our grading system, FSD was detected in 339 women (67.8 %); Mild FSD in 20.4%, mild to moderate in 41.6%, moderate in 15.3%, and severe in 22.7%. Mean scores of desire show a linear trend of reduction from 3.8 in mild to 3.36 in mild to moderate to 2.25 in moderate and markedly reduced to 2.1 in severe grade. This difference was highly statistically significant (p= 0.002). The same was reported in arousal, orgasm, and satisfaction domains, while in lubrication and pain domains, the difference was not statistically significant.ConclusionIn this study, our grading system was complementary to the FSFI. Moreover, it seems to be more practical and useful in grading the severity of FSD.     

Effect of a dCTP:dTTP pool imbalance on DNA replication fidelity in Friend murine erythroleukemia cells

Nucleotide pool imbalances have been reported to affect the fidelity of DNA replication and repair in prokaryotic and eukaryotic cells. We have reported previously that the mutagen-hypersensitive thymidine kinase (TK)-deficient Friend erythroleukemia (FEL) cells (subclones 707BUF and 707BUE), have a more than sixfold increase in the dCTP:dTTP pool ratio when compared to that of wild-type, TK-positive (TK(+)) clone 707 cells. In this study we present the results of an investigation of the effect of the dCTP:dTTP pool imbalance on the accuracy of DNA replication within 707BUF cells. We examined the spontaneous mutation spectra occurring at the adenine phosphoribosyltransferase (aprt) locus within clone 707 (TK(+)) and 707BUF (TK(-)) FEL cells. Mutations recovered at the aprt locus in FEL cells comprised: base substitutions (43:73), frameshifts (14:13.5), and deletions (43:13.5) [clone 707 (TK(+)):707BUF (TK(-)), respectively, expressed as percentages]. A comparison of the mutation spectra obtained for the two cell lines did not reveal any significant increase in misincorporation of dCTP, the nucleotide in excess, in 707BUF (TK(-)) cells, during DNA replication synthesis. These data suggest that the dCTP:dTTP pool imbalance does not alter the fidelity of DNA replication synthesis in 707BUF (TK(-)) FEL cells. Rather, the predominance of GC --> AT transitions (53%) in the 707BUF (TK(-)) spectrum may reflect a reduced efficiency of repair by uracil DNA glycosylase of uracil residues within these cells.     

Lesion of areas 17/18/19: effects on the cat's performance in a binary detection task

Summary The ability of two cats to discriminate between two geometrical outline patterns in the presence of superimposed Gaussian visual noise — i.e. in a binary detection task — was tested before and after bilateral removal of cortical areas 17, 18 and 19. The detection probability P_D was measured as a function of the signal-to-noise ratio. After a lesion of areas 17, 18 and 19 both cats were unable to carry out the discrimination tasks. Their detection performance dropped to chance level, but after an extensive phase of retraining (3 months) they regained the ability to discriminate visual patterns. It was thus possible to obtain detection curves and to determine a measure of a performance which is predominantly bound to be mediated by extra-geniculo-cortical systems. The detection capacity was abnormally low with both large and small patterns. However, the detection of stationary small patterns was similar to the performance of cats with 17/18 lesions; the detection of stationary large patterns was only slightly better than the detection of small patterns and much worse than the comparable performance of cats with 17/18 lesions. Furthermore the cats with lesions of areas 17/18/19 were unable to discriminate moving patterns, their performances being at chance level, whereas for the cats with 17/18 lesions the detection of moving and stationary patterns was equal.Supported by the Deutsche Forschungsgesellschaft     

Reduced P300 in depression: Evidence from a flanker task and impact on ERN,CRN, and Pe

Individuals with current depression show reduced amplitude of the P300 component of the stimulus-locked event-related potential (ERP)—an effect most often examined in oddball tasks. Although imperative stimuli in response-monitoring paradigms (e.g., the flanker task), also elicit a P300, it is unclear whether a blunted P300 can be observed in depression in these tasks. Moreover, the P300 overlaps with the correct-response negativity (CRN) and error-related negativity (ERN), and is similar to the error positivity (Pe)—response-locked ERPs frequently examined in flanker tasks. The current study examined the stimulus-locked P300 and response-monitoring ERPs on error (i.e., ERN, Pe) and correct responses (i.e., CRN) during an arrowhead flanker task in 72 individuals with a current depressive disorder and 42 never depressed healthy individuals. Consistent with findings from oddball tasks, P300 amplitude was reduced among participants with depression. Further, results indicated increased ERN and CRN, and decreased Pe, in depression. However, when the blunted P300 was included in analyses, group differences in response-monitoring ERPs were no longer evident. Accordingly, P300 amplitudes were correlated negatively with the ERN/CRN and positively with Pe in both groups. A blunted P300 in depression can be observed in speeded response tasks, and can produce apparent increases in ERN and CRN due to ERP component overlap. Further, reduced Pe in participants with depression may reflect a reduced P300 to error commission. These data highlight the central role of reduced P300 in clinical depression, and demonstrate that this effect can be observed across both stimulus- and response-locked ERPs in speeded response tasks.