Numerous studies have reported relationships between gender and cerebral event-related potentials (ERPs) recorded from the human scalp. Recent studies have suggested that the influences of gender on ERPs may differ in persons with schizophrenia compared to healthy controls. In a further evaluation of the influences of this critical subject variable on ERP characteristics in schizophrenia, ERPs of age- and gender-matched groups (n = 72 each) of unmedicated schizophrenic patients and healthy controls were compared. ERPs elicited by left and right median nerve stimulation, checkerboard pattern visual flash, and auditory clicks were recorded from 15 scalp leads. The results confirm previous findings showing that: (1) number of comparable gender effects present in the ERP records of these two large study groups and (2) specific Diagnosis x Gender interactions suggesting that schizophrenic illness may modify normal gender influences on ERP characteristics. These data illustrate the point that matching schizophrenic patients and healthy control populations for gender is essential but not sufficient. Even in carefully matched groups, gender confounding can persist as a source of error variance because the influence can vary for different diagnostic groups.

No abstract

No abstract

Objective Global precedence (GP) is an individual’s ability to readily identify global (gestalt) features when both global and local (internal) details are presented. Prior research shows that both age and neurodegenerative diseases, such as Alzheimer’s, affect GP. The goal of the current study is to examine differences in GP between individuals with early-onset Alzheimer’s disease (EOAD; before age 65) and healthy controls (HC). Method Fourteen EOAD patients and 6 HC’s recruited from Behavioral Neurology at an academic medical center were included in the current analysis. EOAD participants were diagnosed by clinical history, routine labs, neuroimaging, and neurological examination. Exclusion criteria included unstable medical conditions and history of severe head injury, psychotic disorder, or psychoactive substance use. All participants completed a Mini Mental Status Examination (MMSE) to assess overall cognitive functioning and a 4-item Navon's paradigm task (consisting of a larger letter whose shape is composed of smaller repeats of a different letter) to assess for GP. Results Linear regression analysis was performed, with the total score on Navon task as the dependent variable and age, MMSE score, and study group as predictor variables. Analysis yielded significant findings, suggesting a difference in GP performance between the two groups. However, coefficients suggested that while age did not contribute to the between-group difference, MMSE scores significantly accounted for our findings. In fact, when effects of MMSE scores were controlled, the between-group difference was no longer significant. Conclusion Findings suggest that individuals with EOAD perform worse on tasks of GP, which may be secondary to overall cognitive decline.