The relationship between visual-perception and attention in Chinese with schizophrenia

Normative data for the Color Trails Test in middle-aged and elderly Quebec-French people

OBJECTIVE

Despite the widespread use of the Color Trails Test (CTT) in clinical and research settings, information regarding the impact of sociodemographic variables on test performance in Quebec-French adults and elderly people is non-existent. This study aimed to establish French-Quebec normative data for error scores and completion time on all test trials (CTT1 and CTT2) taking into account the impact of age, education, and sex on test performance.

METHOD

The sample consisted of 169 community-dwelling and healthy Quebec-French individuals aged between 50 and 90 years and having between 6 and 21 years of formal education.

RESULTS

Regression analyses indicated that age was associated with completion time on CTT1 and CTT2. Spearman correlations also revealed that age was positively associated with error scores (CTT1 errors, CTT2 number errors, CTT2 near-misses) and index interference. Education was marginally associated with CTT1 but was not associated with CTT2 completion time or interference index. Education was only associated with the number of errors in the CTT2. Finally, sex was not associated with any variables. Equations to calculate Z scores and percentiles are presented.

CONCLUSIONS

Norms for the CTT will ease the interpretation of executive functioning in Quebec-French adults and the elderly and favor accurate discrimination between normal and pathological cognitive states.

The neural substrates of visual organization in children and adolescents: An fMRI study

Deficient visual organization ability not only indicates possible brain dysfunctions but further affects an individual's daily activities. This study aimed to use functional magnetic resonance imaging (fMRI) to investigate the neural network contributing to visual organization abilities in children and adolescents. A two-choice version of the Hooper Visual Organization Test (T-HVOT) was adapted as the fMRI task for the present study. The effects of age and gender on overall visual perceptual functions and related neural foundations were also analyzed. Seventy children and adolescents were administered with the Test of Visual Perceptual Skill-Third Edition and 41 completed the fMRI scans. The whole-brain fMRI mapping results showed the cortical activation of multiple brain areas relating to visual organization. The greatest cortical activities were seen in the middle occipital gyrus, middle temporal gyrus, middle frontal gyrus and inferior frontal gyrus, and two age groups showed significant differences in cortical activation patterns as well. Gender had no significant effects on visual perceptual functions nor related cortical activation patterns. The overall visual perception functions improve with age, and the different cortical activation patterns indicated that the two groups adopt different strategies while performing visual organization tasks. The sensitivity and spatial resolution of fMRI allowed us to make specific conclusions about cortical regions involved in visual organization function and to provide a reference for objectively judging rehabilitative outcomes.

Color Trails Test: A New Set of Data on Cognitive Flexibility and Processing Speed in Schizophrenia

BACKGROUND

Although schizophrenia patients have been reported to manifest deficits in cognitive flexibility and lower processing speed (measured with i.a., the Color Trails Test, CTT), there still remain a few matters that require further investigation. We have therefore formulated three research aims: 1) to examine the factor structure of CTT in schizophrenia patients and healthy controls, 2) to compare different CTT performance measures in the two groups, 3) to investigate the relationship between these measures and selected psychopathological symptoms in the patient group.

METHODS

Sixty-seven patients with paranoid schizophrenia and 67 healthy controls, matched for gender, age, number of years of education, and overall cognitive functioning underwent assessment of cognitive flexibility and processing speed with the CTT.

RESULTS

Factor analysis of CTT variables based on the principal component method revealed a four-factor solution in both groups. Compared with healthy controls, the patients performed poorer on CTT 1 time, CTT 2 time, 2-1 difference, prompts in CTT 2, and had higher regression factor scores for Factor 1 (reflecting the slower speed of perceptual tracking). Furthermore, significant links were found between some CTT measures, and negative and disorganization symptoms.

CONCLUSIONS

Schizophrenia patients exhibit problems with speed of perceptual tracking and executive processes dependent on processing speed. Our results may be useful for the development of neuropsychological diagnostic methods for schizophrenia patients. It seems that, compared to other CTT indices, CTT 1 time, CTT 2 time, and 2-1 difference are more appropriate measures of cognitive performance in schizophrenia patients.

The developmental relationship between DHEA and visual attention is mediated by structural plasticity of cortico-amygdalar networks

Humans and the great apes are the only species demonstrated to exhibit adrenarche, a key developmental event leading to increased production of dehydroepiandrosterone (DHEA), suggesting that this hormone may play an important evolutionary role. Similarly, visual attention networks have been shown to evolve in a human-specific manner, with some anatomical connections and elements of cortical organization exclusive to our species. Existing studies of human brain development support the notion that DHEA shows significant uptake in cortical structures and the amygdala, and as such, could be involved in the bottom-up regulation of visual attention. Here we examined associations between DHEA, structural covariance of the amygdala with whole-brain cortical thickness, and tests of visual attention, in a longitudinal sample of typically developing children and adolescents 6-22 years of age. We found that DHEA predicted covariance between amygdalar volume and the left occipital pole, right somatosensory parietal cortex and right anterior cingulate cortex. Amygdala-occipital covariance predicted visual awareness; amygdala-parietal covariance predicted visuo-motor dexterity and processing speed; amygdala-prefrontal covariance predicted global attentional impairment. Further, effects of DHEA were above and beyond those of age and sex, as well as distinct from those of pubertal stage, estradiol and testosterone. These findings support the notion that DHEA may play a unique role in shaping amygdala-dependent cortical plasticity and in regulating 'bottom-up' visual attention processes from childhood to young adulthood.

The Associations between Visual Attention and Facial Expression Identification in Patients with Schizophrenia

OBJECTIVE

Visual search is an important attention process that precedes the information processing. Visual search also mediates the relationship between cognition function (attention) and social cognition (such as facial expression identification). However, the association between visual attention and social cognition in patients with schizophrenia remains unknown. The purposes of this study were to examine the differences in visual search performance and facial expression identification between patients with schizophrenia and normal controls, and to explore the relationship between visual search performance and facial expression identification in patients with schizophrenia.

METHODS

Fourteen patients with schizophrenia (mean age=46.36±6.74) and 15 normal controls (mean age=40.87±9.33) participated this study. The visual search task, including feature search and conjunction search, and Japanese and Caucasian Facial Expression of Emotion were administered.

RESULTS

Patients with schizophrenia had worse visual search performance both in feature search and conjunction search than normal controls, as well as had worse facial expression identification, especially in surprised and sadness. In addition, there were negative associations between visual search performance and facial expression identification in patients with schizophrenia, especially in surprised and sadness. However, this phenomenon was not showed in normal controls.

CONCLUSION

Patients with schizophrenia who had visual search deficits had the impairment on facial expression identification. Increasing ability of visual search and facial expression identification may improve their social function and interpersonal relationship.

Psychometric validation and normative data of a second Chinese version of the Hooper Visual Organization Test in children

The Hooper Visual Organization Test (HVOT) is a measure of visuosynthetic ability. Previously, the psychometric properties of the HVOT have been evaluated for Chinese-speaking children aged 5-11 years. This study reports development and further evidence of reliability and validity for a second version involving an extended age range of healthy children and children with developmental disabilities (DD) from 5 to 14 years of age. Rasch analysis revealed that after deletion of 6 items, a 24-item version conformed to a unidimensional scale. The test showed satisfactory internal consistency; 3-week test-retest coefficients all exceeded .85 for three DD subsamples. The second version was able to successfully differentiate between the three DD subgroups (attention-deficit hyperactivity disorder, autism spectrum disorders, and mental retardation) and the healthy control group, with correct classification rates ranging from 86.6% to 94.1%. Its construct validity was supported by expected correlations. Accordingly, age-based normative data were established as a basis for interpretation of performance. In sum, the second Chinese version of the HVOT has good psychometric properties and norms that are suited for use in clinical practice.

Relationship between cognitive functioning and 6-month clinical and functional outcome in patients with first manic episode bipolar I disorder

BACKGROUND

Although cognitive deficits in bipolar disorder have been associated with diminished functional outcome, this relationship has been studied primarily through cross-sectional designs, and has not been studied in patients early in the course of illness. The purpose of this study was to evaluate the impact of cognitive functioning on longitudinal 6-month functional and clinical outcome in recently diagnosed clinically stable patients with bipolar disorder.

METHOD

A total of 53 recently diagnosed patients with DSM-IV bipolar disorder type I were assessed within 3 months of their first manic episode using a neuropsychological battery measuring verbal/pre-morbid intellectual functioning, learning/memory, spatial/non-verbal reasoning, attention/processing speed and executive function. Functional outcome was assessed at baseline and 6 months using the Multidimensional Scale of Independent Functioning (MSIF) and DSM-IV Global Assessment of Functioning Scale (GAF). Clinical outcome was assessed with symptom ratings and by monitoring onset of new mood episodes.

RESULTS

Memory, particularly verbal learning/memory, was robustly associated with 6-month functional outcome on the MSIF, even after partialling out the influence of mood symptoms and substance abuse co-morbidity. Depression ratings at 6 months, but not cognitive variables, were associated with 6-month GAF scores. Cognitive functioning was not associated with 6-month clinical outcome.

CONCLUSIONS

Memory was associated with 6-month longitudinal functional but not clinical outcome in recently diagnosed patients with bipolar disorder. These data further support the distinction between clinical and functional outcome, and emphasize the need for identification of, and development of treatments for, cognitive impairments early in the course of bipolar disorder.

Seeing is remembering: do deficits in closure affect visual memory recognition in schizophrenia?

INTRODUCTION

Episodic memory is significantly impaired in people with schizophrenia. The precise cause of this impairment has yet to be determined, as the formation of episodic memories is dependent on other processes, some of which also show impairment in schizophrenia. One such process is closure, that is, the filling-in of missing information. Failure to close adequately incomplete stimuli may cause people with schizophrenia to store inadequate or piecemeal representations in memory.

METHODS

Forty people with schizophrenia and 21 healthy comparison subjects participated in the study. The experiment was divided into six blocks, each of which involved both an encoding and a recognition phase. During the encoding phase, 20 figures were presented sequentially and participants had to determine whether each was symmetric or asymmetric. These figures were either complete or fragmented at three different levels. In subsequent recognition phase, 40 abstract figures (20 new and 20 old) were presented. All figures were complete in this phase.

RESULTS

Memory performance of both groups was affected similarly by fragmentation, with an additional increase in performance afforded by a slight fragmentation for participants with schizophrenia.

CONCLUSION

Slight fragmentation may have induced a perceptual difficulty that was mild enough to increase visual processing without compromising it. Closure was thus not involved in the episodic memory deficit of people with schizophrenia.

Effects of sad mood on facial emotion recognition in Chinese people

This study examined the influence of sad mood on the judgment of ambiguous facial emotion expressions among 47 healthy volunteers who had been induced to feel sad (n=13), neutral (n=15), or happy (n=19) emotions by watching video clips. The findings suggest that when the targets were ambiguous, participants who were in a sad mood tended to classify them in the negative emotional categories rather than the positive emotional categories. Also, this observation indicates that emotion-specific negative bias in the judgment of facial expressions is associated with a sad mood. The finding argues against a general impairment in decoding facial expressions. Furthermore, the observed mood-congruent negative bias was best predicted by spatial perception. The findings of this study provide insights into the cognitive processes underlying the interpersonal difficulties experienced by people in a sad mood, which may be predisposing factors in the development of clinical depression.

Improvement of sustained attention and visual and movement skills, but not clinical symptoms, after dehydroepiandrosterone augmentation in schizophrenia: a randomized, double-blind, placebo-controlled, crossover trial

BACKGROUND

Dehydroepiandrosterone (DHEA) augmentation has been reported, in a preliminary fashion, to be useful in the management of schizophrenia symptoms and side effects. In this study, the intention was to investigate the efficacy and safety of DHEA administration to ongoing antipsychotic medication in a multicenter, 12-week, double-blind, randomized, placebo-controlled, crossover trial.

METHODS

Fifty-five of 62 inpatients and outpatients with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, diagnosis of schizophrenia completed the trial. Patients were randomly allocated to 2 treatment groups receiving either DHEA (200 mg/d) or placebo for 6 weeks with the crossover between DHEA and placebo occurring after 6 weeks. Patients continued to receive their regular antipsychotic medication for the duration of the study.

RESULTS

Compared with placebo, DHEA administration did not produce significant improvement in clinical symptoms, side effects, and quality-of-life scores. However, 6 weeks of DHEA administration (but not placebo) was associated with a significant improvement in Positive and Negative Symptom Scale ratings compared with baseline. Furthermore, 6 weeks of DHEA treatment was associated with significant improvement in cognitive functions of visual sustained attention and visual and movement skills compared with placebo conditions. The DHEA augmentation was associated with elevations of serum concentrations of both DHEA and its sulfate ester. The DHEA treatment was well tolerated without any serious adverse effects.

CONCLUSION

This short-term study does not support DHEA's value as an effective adjunct in the treatment of symptoms, side effects, and quality-of-life impairment in schizophrenia, while suggesting that DHEA improves sustained attention and visual and movement skills. A long-term, large-scale study with a broader dose range is warranted to further investigate DHEA's role in the management of schizophrenia.