Neural correlates of immediate and delayed word recognition memory: An MEG study

Gender Difference in Cognitive Function Among Stable Schizophrenia: A Network Perspective

OBJECTIVE

To investigate the gender differences and influencing factors of cognitive function in stable schizophrenic patients, and to explore the cognitive characteristics of male and female patients.

METHODS

A total of 298 patients with chronic schizophrenia were divided into two groups according to gender. The differences of demographic and clinical characteristics between the two groups were firstly analyzed. Then the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was used to measure their cognitive function, and the correlation between cognitive function and demographic characteristics and clinical characteristics was analyzed. Finally, the gender-based cognitive characteristics were explored through network analysis.

RESULTS

There was no significant difference in the RBANS total score and sub-item score between the male schizophrenia and female schizophrenia patients. Correlation analysis showed that RBANS total score was inversely proportional with age, duration and Positive and Negative Syndrome Scale (PANSS) score in male schizophrenia, while being directly proportional with age at onset and inversely proportional with PANSS score in female schizophrenia. Network analysis showed that language was the core of cognitive function for male schizophrenia, and the delayed memory was the core of cognitive function for female schizophrenia.

CONCLUSION

There was no significant gender difference in cognitive function score among patients with stable schizophrenia. The core cognitive functions of male and female schizophrenia are language and delayed memory, respectively.

Language-Related Neurophysiological Deficits in Schizophrenia

Schizophrenia is a severe psychiatric disorder that affects all aspects of one's life with several cognitive and social dysfunctions. However, there is still no objective and universal index for diagnosis and treatment of this disease. Many researchers have studied language processing in schizophrenia since most of the patients show symptoms related to language processing, such as thought disorder, auditory verbal hallucinations, or delusions. Electroencephalography (EEG) and magnetoencephalography (MEG) with millisecond order high temporal resolution, have been applied to reveal the abnormalities in language processing in schizophrenia. The aims of this review are (a) to provide an overview of recent findings in language processing in schizophrenia with EEG and MEG using neurophysiological indices, providing insights into underlying language related pathophysiological deficits in this disease and (b) to emphasize the advantage of EEG and MEG in research on language processing in schizophrenia.

Immediate auditory repetition of words and nonwords: an ERP study of lexical and sublexical processing

ERPs were elicited to (1) words, (2) pseudowords derived from these words, and (3) nonwords with no lexical neighbors, in a task involving listening to immediately repeated auditory stimuli. There was a significant early (P200) effect of phonotactic probability in the first auditory presentation, which discriminated words and pseudowords from nonwords; and a significant somewhat later (N400) effect of lexicality, which discriminated words from pseudowords and nonwords. There was no reliable effect of lexicality in the ERPs to the second auditory presentation. We conclude that early sublexical phonological processing differed according to phonotactic probability of the stimuli, and that lexically-based redintegration occurred for words but did not occur for pseudowords or nonwords. Thus, in online word recognition and immediate retrieval, phonological and/or sublexical processing plays a more important role than lexical level redintegration.