A method to combine cognitive and neurophysiological assessments of the elderly.

Background: The development of better treatments for brain diseases of the elderly will necessitate more sensitive and efficient means of repeatedly assessing an individual's neurocognitive status.

Aim: To illustrate the development of an assessment combining episodic memory and working memory tasks with simultaneous electroencephalography and evoked potential (EP) brain function measures.

Methods: Data from matched groups of elderly subjects with mildly impaired episodic verbal memory on neuropsychological tests and those with no objective signs of impairment were used for scale development.

Combined neuropsychological and neurophysiological assessment of drug effects on groups and individuals.

An initial standardized approach for combining neuropsychological and neurophysiological measures in order to assess the neurocognitive effects of drugs in groups and individuals is introduced. Its application is illustrated with sedatives, antiepileptic drugs, psychostimulants, antihistamines, and intoxicants. Task performance, electroencephalography, and evoked potential measures during computerized attention and memory testing that are most sensitive to drug effects are identified in a sample population and then applied to individuals.

Distinct cognitive neurophysiologic profiles for lamotrigine and topiramate.

Purpose: To contrast the effects of lamotrigine (LTG) and topiramate (TPM) on cognitive task-related and resting-state EEG and evoked potential (EP) measures.

Methods: We used a double-blind, randomized, crossover design. Healthy adults (N = 29) had two 8-week periods of dose escalation, 4 weeks of drug maintenance (300 mg daily), and 4 weeks of washout.

Neurophysiological and subjective profile of marijuana with varying concentrations of cannabinoids.

This study investigated the contribution of different cannabinoids to the subjective, behavioral and neurophysiological effects of smoked marijuana. Healthy marijuana users (12 men, 11 women) participated in four sessions. They were randomly assigned to a low or a high delta9-tetrahydrocannabinol group (THC; 1.

Bilateral hippocampal volume reduction in adults with post-traumatic stress disorder: a meta-analysis of structural MRI studies.

Over the last decade a significant number of studies have reported smaller hippocampal volume in individuals with symptoms of post-traumatic stress disorder (PTSD) relative to control groups, and in some cases hemispheric asymmetries in this effect have been noted. However these reported asymmetries have not been in a consistent direction, and other well-controlled studies have failed to observe any hippocampal volume difference. This paper reports a systematic review and meta-analysis of studies in which hippocampal volume was estimated from magnetic resonance images in adult patients with PTSD.

The impact of moderate sleep loss on neurophysiologic signals during working-memory task performance.

Study Objectives: This study examined how sleep loss affects neurophysiologic signals related to attention and working memory.

Design: Subjective sleepiness, resting-state electroencephalogram, and behavior and electroencephalogram during performance of working-memory tasks were recorded in a within-subject, repeated-measures design.

Setting: Data collection occurred in a computerized laboratory setting.

Task-related EEG and ERP changes without performance impairment following a single dose of phenytoin.

Objectives: The acute effects of a single, low dose of phenytoin on behavioral and neurophysiological measures of cognitive function were examined in healthy adults.

Methods: Electroencephalograms (EEGs) were recorded from 7 healthy volunteers while they performed spatial working memory tasks and while they rested quietly. Behavioral measures, EEG power spectra, and event-related potentials (ERPs) were compared between separate sessions in which subjects ingested either 10mg/kg of phenytoin or placebo.

Monitoring task loading with multivariate EEG measures during complex forms of human-computer interaction.

Electroencephalographic (EEG) recordings were made while 16 participants performed versions of a personal-computer-based flight simulation task of low, moderate, or high difficulty. As task difficulty increased, frontal midline theta EEG activity increased and alpha band activity decreased. A participant-specific function that combined multiple EEG features to create a single load index was derived from a sample of each participant's data and then applied to new test data from that participant.

Tracking the cognitive pharmacodynamics of psychoactive substances with combinations of behavioral and neurophysiological measures.

Many common pharmacological treatments have effects on cognitive ability. Psychometric task batteries used to characterize such effects do not provide direct information about treatment-related changes in brain function. Since overt task performance reflects motivation and effort as well as ability, behavioral measures alone may overestimate or underestimate the impact of a pharmacological intervention on brain function.

Neurophysiological signals of working memory in normal aging.

To examine how neurophysiological signals of working memory (WM) change with normal aging, we recorded EEGs from healthy groups (n=10 each) of young (mean age=21 years), middle-aged (mean=47 years), and older (mean=69 years) adults. EEGs were recorded while subjects performed easy and difficult versions of a spatial WM task. Groups were matched for IQ (mean=123; WAIS-R) and practiced in task performance.