Association between social functioning and prefrontal cortex function during a verbal fluency task in schizophrenia: A near-infrared spectroscopic study

A scoping review of utilization of the verbal fluency task in Chinese and Japanese clinical settings with near-infrared spectroscopy

This review targets the application of the Verbal Fluency Task (VFT) in conjunction with functional near-infrared spectroscopy (fNIRS) for diagnosing psychiatric disorders, specifically in the contexts of China and Japan. These two countries are at the forefront of integrating fNIRS with VFT in clinical psychiatry, often employing this combination as a complementary tool alongside traditional psychiatric examinations. Our study aims to synthesize research findings on the hemodynamic responses elicited by VFT task in clinical settings of the two countries, analyzing variations in task design (phonological versus semantic), stimulus modality (auditory versus visual), and the impact of language typology. The focus on China and Japan is crucial, as it provides insights into the unique applications and adaptations of VFT in these linguistically and culturally distinct environments. By exploring these specific cases, our review underscores the importance of tailoring VFT to fit the linguistic and cultural context, thereby enhancing its validity and utility in cross-cultural psychiatric assessments.

Evidence that the frontal pole has a significant role in the pathophysiology of schizophrenia

Different regions of the cortex have been implicated in the pathophysiology of schizophrenia. Recently published data suggested there are many more changes in gene expression in the frontal pole (Brodmann's Area (BA) 10) compared to the dorsolateral prefrontal cortex (BA 9) and the anterior cingulate cortex (BA 33) from patients with schizophrenia. These data argued that the frontal pole is significantly affected by the pathophysiology of schizophrenia. The frontal pole is a region necessary for higher cognitive functions and is highly interconnected with many other brain regions. In this review we summarise the growing body of evidence to support the hypothesis that a dysfunctional frontal pole, due at least in part to its widespread effects on brain function, is making an important contribution to the pathophysiology of schizophrenia. We detail the many structural, cellular and molecular abnormalities in the frontal pole from people with schizophrenia and present findings that argue the symptoms of schizophrenia are closely linked to dysfunction in this critical brain region.

A scoping review of near infrared spectroscopy studies employing a verbal fluency task in bipolar disorder

BACKGROUND

Deficits in cognitive functioning, including attention, memory, and executive functions, along with impairments in language production, are present in patients with bipolar disorder (BD) patients during mood phases, but also during euthymia.Verbal fluency tasks (VFTs), being able to evaluate integrity of a wide range of cognitive domains and represent, can be used to screen for these disturbances. Neuroimaging studies, including Near-InfraRed Spectroscopy (NIRS), have repeatedly showed widespread alterations in the prefrontal and temporal cortex during the performance of VFTs in BD patients. This review aims to summarize the results of NIRS studies that evaluated hemodynamic responses associated with the VFTs in prefrontal and temporal regions in BD patients.

METHODS

We performed a scoping review of studies evaluating VFT-induced activation in prefrontal and temporal regions in BD patients, and the relationship between NIRS data and various clinical variables.

RESULTS

15 studies met the inclusion criteria. In BD patients, compared to healthy controls, NIRS studies showed hypoactivation of the dorsolateral prefrontal cortex, ventrolateral prefrontal cortex and anterior temporal regions. Moreover, clinical variables, such as depressive and social adaptation scores, were negatively correlated with hemodynamic responses in prefrontal and temporal regions, while a positive correlation were reported for measures of manic symptoms and impulsivity.

LIMITATIONS

The heterogeneity of the studies in terms of methodology, study design and clinical characteristics of the samples limited the comparability of the findings.

CONCLUSIONS

Given its non-invasiveness, good time-resolution and no need of posturalconstraint, NIRS technique could represent a useful tool for the evaluation of prefrontal and temporal haemodynamic correlates of cognitive performances in BD patients.

Prefrontal Cortex Activation During Verbal Fluency Task and Tower of London Task in Schizophrenia and Major Depressive Disorder

Background: Cognitive dysfunction is a common clinical feature of mental disorders. A number of functional near-infrared spectroscopy (fNIRS) studies have shown reduced prefrontal activation during the verbal fluency task (VFT) in schizophrenia (SZ) and major depressive disorder (MDD). However, no studies have examined and compared the brain activation patterns during the Tower of London (TOL), which is another classic, high-sensitivity executive function testing tool, in these two serious mental disorders. This study aimed to assess the characteristics of brain activation during the two different cognitive tasks in SZ and MDD patients. Methods: This study recruited 30 patients with SZ, 30 patients with MDD, and 30 demographically matched healthy controls (HCs). The hemodynamic changes of the prefrontal cortex (PFC) were measured using 32-channel fNIRS during performance of the TOL task and VFT task. Results: SZ patients showed poorer VFT performance than MDD patients and HCs, and the two patient groups showed poorer TOL performance than HCs. Compared to HCs, both of the patient groups exhibited a significant decreased activation in the extensive PFC. Particularly in certain channels in the dorsolateral PFC (DLPFC), SZ patients exhibited significantly decreased hemodynamic changes than the MDD patients. Conclusions: Patients with SZ and MDD have different levels of impairment in different cognitive domains and different patterns of brain activation during the two cognitive tasks. Further research is needed to determine the use of fNIRS for clinical evaluation and diagnosis.

Regional brain atrophy is related to social cognition impairment in multiple sclerosis

BACKGROUND

Multiple sclerosis exhibits specific neuropathological phenomena driving to both global and regional brain atrophy. At the clinical level, the disease is related to functional decline in cognitive domains as the working memory, processing speed, and verbal fluency. However, the compromise of social-cognitive abilities has concentrated some interest in recent years despite the available evidence suggesting the risk of disorganization in social life. Recent studies have used the MiniSEA test to assess the compromise of social cognition and have found relevant relationships with memory and executive functions, as well as with the level of global and regional brain atrophy.

OBJECTIVE

The present article aimed to identify structural changes related to socio-cognitive performance in a sample of patients with relapsing-remitting multiple sclerosis.

METHODS

68 relapsing-remitting multiple sclerosis Chilean patients and 50 healthy control subjects underwent MRI scans and neuropsychological evaluation including social-cognition tasks. Total brain, white matter, and gray matter volumes were estimated. Also, voxel-based morphometry was applied to evaluate regional structural changes.

RESULTS

Patients exhibited lower scores in all neuropsychological tests. Social cognition exhibited a significant decrease in this group mostly related to the declining social perception. Normalized brain volume and white matter volume were significantly decreased when compared to healthy subjects. The regional brain atrophy analysis showed that changes in the insular cortex and medial frontal cortices are significantly related to the variability of social-cognitive performance among patients.

CONCLUSIONS

In the present study, social cognition was only correlated with the deterioration of verbal fluency, despite the fact that previous studies have reported its link with memory and executive functions. The identification of specific structural correlates supports the comprehension of this phenomenon as an independent source of cognitive disability in these patients.

Probing depression, schizophrenia, and other psychiatric disorders using fNIRS and the verbal fluency test: A systematic review and meta-analysis

Accessible neuroimaging tools that can identify specific frontal lobe dysfunction associated with psychiatric disorders could be useful for improving disease diagnosis and prognosis and treatment development. Functional near-infrared spectroscopy (fNIRS), in conjunction with the verbal fluency test (VFT), has emerged as an inexpensive and convenient method for understanding psychiatric disorders. However, questions remain regarding the specificity and uniqueness of fNIRS measurements for different disorders and the soundness of the methods applied previously. To address these knowledge gaps, we conducted a systematic review and meta-analysis of fNIRS studies using the VFT to probe psychiatric disorders. A literature search was conducted using PubMed and PsycINFO on October 27, 2020. Overall, 82% and 49% of the 121 included studies reported significantly reduced changes in oxyhemoglobin concentrations (HbO) and significantly fewer produced words during the VFT in psychiatric patients compared with healthy controls, respectively. For most psychiatric disorders, changes in HbO are more sensitive than changes in deoxyhemoglobin concentrations and VFT performance to detect psychopathologies. In addition, meta-analyses based on the proportion of channels that exhibited significant differences in HbO changes between patients and controls and on the effect sizes of group differences consistently showed that for major depression and schizophrenia, hypoactivation could be found across the frontotemporal regions, but its topographical distribution is disorder-specific. Thus, the fNIRS-VFT paradigm holds promise for understanding, detecting, and differentiating psychiatric disorders, and has the potential for developing accessible neuroimaging biomarkers for different psychiatric disorders. The findings are discussed with regard to the strengths and weaknesses of the applied methods, following by recommendations.

Role of Executive Function in Response to a Problem Solving Based Psychoeducational Intervention in Adolescents with Psychosis: The PIENSA Trial Revisited

An improvement in negative symptoms and a reduction in the number of visits to the emergency department have been reported in a problem solving based psychoeducational group intervention (PE) for adolescents with psychosis relative to a nonstructured group (NS). One of the factors that may play a role on the response to PE treatment is executive function (EF), a crucial cognitive domain for problem-solving performance. We aimed to examine the role of EF in response to PE treatment versus an NS group. We examined the associations between changes in cognition and in clinical/functional variables within each treatment group using Spearman-ranked and partial correlation analyses. A total of 22 individuals (mean age: 16.3) were randomized to PE (N = 10) and NS (N = 12). We found an association between improvements in EF performance and a reduction in positive symptoms (r_s = –0.756, p = 0.030 for semantic fluency), reduction in negative symptoms (r = 0.758, p = 0.029 for semantic; r_s = –0,733, p = 0.025 for verbal fluency), and reduction in the number of visits to the emergency department (r = –0,743, p = 0.035 for semantic fluency) in the PE group. No associations were found in the NS group. Our results suggest that EF may play a role in the specific improvements observed in the PE group. This may have implications in the development of new areas of clinical intervention focusing on the role of cognitive functioning in response to psychosocial treatments in psychosis.

Influence of acute combined physical and cognitive exercise on cognitive function: an NIRS study

The purpose of this study is to investigate the effects of different types of acute exercise on cognitive function and cerebral oxygenation. A within-subject design was adopted. In total, 20 healthy older adults were enrolled in the study. They came to the laboratory individually on four separate days and completed four conditions of activity. Four conditions were sedentary reading control (RC), cognitive exercise (CE), physical exercise (PE) and cognitive + physical exercise (CE + PE). During these visits, participants completed the Stroop task before and immediately after the experimental condition, which consisted of 15 min of aerobic exercise, verbal fluency task (VFT), and dual task. The Stroop task included the following two conditions: a naming condition and an executive condition. The fNIRS is an optical method using near-infrared light to measure relative changes of oxygenated (O2Hb) and deoxygenated (HHb) hemoglobin in the cortex. The results indicate that acute exercise facilitates performance for executive tasks, not only combined cognition, but also the different results between combined exercise and single exercise. The fNIRS findings showed that acute single exercise influences oxygenation for executive tasks but not for naming tasks. Greater improvement was observed in the post-exercise session of combined exercise during the modified Stroop. These findings demonstrate that acute single exercise, single cognition exercise, and combined exercise enhanced the performance of the inhibition control task. Only acute combined exercise has a general facilitative effect on inhibition control. Combined exercise was shown to be superior to single exercise for task-efficient cerebral oxygenation and improved oxygen utilization during cortical activation in older individuals. Also, to maximize the performance of cognition it may be important for older adults to take part in more cognitive demand exercise or take more kinds of exercise.

Microstructural abnormalities in callosal fibers and their relationship with cognitive function in schizophrenia: A tract-specific analysis study

INTRODUCTION

The corpus callosum serves the essential role of relaying cognitive information between the homologous regions in the left and the right hemispheres of the brain. Cognitive impairment is a core dysfunction of schizophrenia, but much of its pathophysiology is unknown. The aim of this study was to elucidate the association between microstructural abnormalities of the corpus callosum and cognitive dysfunction in schizophrenia.

METHODS

We examined stepwise multiple regression analysis to investigate the relationship of the fractional anisotropy (FA) of callosal fibers in each segment with z-scores of each brief assessment of cognition in schizophrenia subtest and cognitive composite score in all subjects (19 patients with schizophrenia [SZ group] and 19 healthy controls [HC group]). Callosal fibers were separated into seven segments based on their cortical projection using tract-specific analysis of diffusion tensor imaging.

RESULTS

The FA of callosal fibers in the temporal segment was significantly associated with z-scores of token motor test, Tower of London test, and the composite score. In the SZ group, the FA of callosal fibers in the temporal segment was significantly associated with the z-score of the Tower of London test. In addition, the FA of callosal fibers in temporal segment showed significant negative association with the positive and negative syndrome scale negative score in the SZ group. Compared to the HC group, the FA in temporal segment was significantly decreased in the SZ group.

CONCLUSION

Our results suggest that microstructural abnormalities in the callosal white matter fibers connecting bilateral temporal lobe cortices contribute to poor executive function and severe negative symptom in patients with schizophrenia.

Mean deviation based identification of activated voxels from time-series fMRI data of schizophrenia patients

Background: Schizophrenia is a serious mental illness affecting different regions of the brain, which causes symptoms such as hallucinations and delusions. Functional magnetic resonance imaging (fMRI) is the most popular technique to study the functional activation patterns of the brain. The fMRI data is four-dimensional, composed of 3D brain images over time. Each voxel of the 3D brain volume is associated with a time series of signal intensity values. This study aimed to identify the distinct voxels from time-series fMRI data that show high functional activation during a task.

Methods: In this study, a novel mean-deviation based approach was applied to time-series fMRI data of 34 schizophrenia patients and 34 healthy subjects. The statistical measures such as mean and median were used to find the functional changes in each voxel over time. The voxels that show significant changes for each subject were selected and thus used as the feature set during the classification of schizophrenia patients and healthy controls.

Results: The proposed approach identifies a set of relevant voxels that are used to distinguish between healthy and schizophrenia subjects with high classification accuracy. The study shows functional changes in brain regions such as superior frontal gyrus, cuneus, medial frontal gyrus, middle occipital gyrus, and superior temporal gyrus.

Conclusions: This work describes a simple yet novel feature selection algorithm for time-series fMRI data to identify the activated brain voxels that are generally affected in schizophrenia. The brain regions identified in this study may further help clinicians to understand the illness for better medical intervention. It may be possible to explore the approach to fMRI data of other psychological disorders.

Quetiapine Modulates Histone Methylation Status in Oligodendroglia and Rescues Adolescent Behavioral Alterations of Socially Isolated Mice

Epigenetic alterations and impaired oligodendroglial myelination in the prefrontal cortex have been shown to correlate with behavioral and cognitive dysfunctions in social deprivation. Our previous study demonstrated that quetiapine, an atypical antipsychotic, could promote oligodendroglial differentiation and myelination. However, whether and how quetiapine could be beneficial in modulating aberrant epigenetic alterations in oligodendroglial cells and relieving behavioral alterations from social isolation is unknown. In this study, quetiapine was orally administered in adolescent mice undergoing mild stress of social isolation. We firstly confirmed that social isolation during a novel adolescent period could impair sociability, but not locomotive behaviors in mice. Moreover, quetiapine alleviated myelin deficits, and increased levels of histone methylation (H3K9me3) in mature oligodendroglia in the prefrontal cortex of socially isolated mice. Strikingly, quetiapine treatment significantly increased locomotive activity, and successfully reversed social avoidance behavior of the socially isolated mice. Taken together, our data suggest that quetiapine may rescue behavioral changes from social isolation through modulating epigenetic status toward the beneficial direction for oligodendroglial maturation, providing new insights into the pharmacological mechanism of quetiapine for mental illnesses.

STUDIES ON SCHIZOPHRENIA AND DEPRESSIVE DISEASES BASED ON FUNCTIONAL NEAR-INFRARED SPECTROSCOPY

Many investigations have been carried out on functional near infrared spectroscopy (fNIRS) applications in depression and schizophrenia patients that are most mysterious and costliest mental disorders in current society. fNIRS is a new optical method which assesses brain cortex hemodynamic and nervous activities non-invasively and it has been used in medicine as a study tool. Most of the researches of this approach have assessed the homodynamic response of frontal and temporal regions by means of various cognitive tasks. In this research, first, the cognitive task execution techniques have been explained concisely, and then some findings of fNIRS-based researches about depression and schizophrenia have been summarized and assessed. In fNIRS studies that have used various devices with different number of channels, the brain cortex functionality in schizophrenia and depressive patients has been investigated. The results demonstrate that a decrease in prefrontal regions activities can be observed in schizophrenia and depressive patients. Also more detailed studies illustrate ventrolateral, prefrontal and frontopolar region disorders. In severe depressive patients, a decrease in activities of prefrontal and temporal regions has been detected. Therefore, by paying attention to the deficiencies in these regions’ functions, it is possible to treat these diseases.

Comparison of changes in the oxygenated hemoglobin level during a 'modified rock-paper-scissors task' between healthy subjects and patients with schizophrenia

AIM

The purpose of this study, using single-event-related near-infrared spectroscopy (NIRS), was to examine the psychophysiological and social function assessment of 30 schizophrenic patients during a modified rock-paper-scissors task.

METHODS

We set up a screen in front of the subjects, on which pictures of hand-gestures for rock, paper, and scissors were randomly presented. Subjects were asked to give verbal answers under the conditions of win, lose, and draw, respectively. Using the 44-channel NIRS system, we evaluated the maximum amplitude of oxygenated hemoglobin, latency, and the area based on the arithmetic mean of resulting values after the task between 30 outpatients with schizophrenia and 30 healthy subjects, and analyzed the frontal pole area, dorsolateral prefrontal region, and parietal association area as regions of interest (ROI).

RESULTS

In schizophrenic patients, oxygenated hemoglobin changes (Δoxy-Hb) when losing the task showed a significantly lower level of Δoxy-Hb in ROI than controls. In addition, a significant positive correlation was observed between the Global Assessment of Functioning Scale and Δoxy-Hb in ROI, and a significant negative correlation was observed between the Negative Syndrome scale of the Positive and Negative Syndrome Scale and Δoxy-Hb in ROI.

CONCLUSION

From these results, we conclude that Δoxy-Hb levels when performing the modified rock-paper-scissors task assessed using NIRS may be a useful psychophysiological marker to evaluate the cognitive and social functions of schizophrenic patients.

Negative Symptoms and Cognitive Impairments in Schizophrenia: Two Key Symptoms Negatively Influencing Social Functioning

Schizophrenia is a chronic, disabling disorder, which commonly emerges in adolescence and young adulthood. While pharmacological treatment with currently available second-generation antipsychotics exerts beneficial effects on the positive symptoms of schizophrenia, they have little effect on negative symptoms or cognitive deficits. Because these two types of symptoms are enduring, and negatively impact social functioning throughout the course of the illness, there is an urgent requirement to develop new effective therapeutic approaches to manage them. Negative symptoms have proven difficult to assess accurately because of their complexity, even with commonly used clinical rating scales such as the Scales for Assessment of Negative Symptoms (SANS). In this context, new "next-generation" assessment tools have recently been developed, which include items representing the five domains encompassed by the two established clusters of negative symptoms (diminished expression and avolition), and enable the detection of changes in severity. Despite various therapeutic approaches to alleviating negative symptoms, there are currently no established methods available for clinical practice. Cognitive deficits are also a core feature in the majority of people with schizophrenia, with impaired performance observed across many cognitive domains, including verbal memory, working memory, attention, and executive functions. Such cognitive deficits are likely associated with either reduced or inefficient function of related distributed neural networks. Psychosocial treatments for cognitive impairments in schizophrenia seem promising given the beneficial effects of cognitive remediation therapy on such impairments, as well as on social functioning, as substantiated in several meta-analytic studies with modest effect sizes. Furthermore, using functional neuroimaging techniques, the size of these therapy-induced beneficial changes in neurocognitive performance has been demonstrated to be correlated with the degree of the changes in brain activation during performing some cognitive tasks in the prefrontal and temporal cortices. This suggests neurobiological effects are exerted by psychosocial cognitive remediation treatments.

Frontal activity measured by near-infrared spectroscopy in patients taking different atypical antipsychotic drugs: A cross-sectional study

Using near-infrared spectroscopy, we examined changes in the concentration of oxygenated hemoglobin ([oxy-Hb]) in the frontal lobe during a verbal fluency task in 20 patients with schizophrenia (10 patients each receiving olanzapine [OLZ] and risperidone [RIS]) and 10 healthy controls. We found that [oxy-Hb] levels in the prefrontal region were higher in the patients receiving OLZ than in those receiving RIS. These results suggest that antipsychotic drugs have different effects on cerebral hemodynamic patterns, which may reflect frontal lobe function. Further studies with a larger sample size are needed to verify our preliminary findings.

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.