Lead (Pb) neurotoxicology and cognition.

Lead (Pb) is a neurotoxic substance. While it is widely understood that Pb exposure in early childhood adversely impacts neurodevelopment and intelligence, other aspects of cognition that are negatively affected, and the neuroanatomy and neurophysiology underlying Pb-related cognitive impairment are not widely appreciated by clinicians. This critical review gives a broad synopsis of the current literature in the field.

Validation of the coin rotation test: a simple, inexpensive, and convenient screening tool for impaired psychomotor processing speed.

Objectives: The Coin Rotation Test is a simple, convenient, and cost-effective measure of psychomotor processing speed that has been used in neurologic examinations at the Louisiana State University Health Sciences system for almost 20 years. On the Coin Rotation Test, participants rotate a coin through serial 180 degree turns using the thumb, index, and middle fingers for 10 seconds. In the current study, we sought to validate the Coin Rotation Test on a hospital-based sample by determining the task's sensitivity and specificity in detecting psychomotor processing speed impairment on a well-established criterion measure, the Grooved Pegboard Test.

Neuropsychological and emotional changes during simulated microgravity: effects of triiodothyronine alendronate, and testosterone.

Introduction: We present the results of a two-experiment study designed to evaluate the neurocognitive and psychological effects of six-degree head-down bedrest and pharmacologic interventions (3,5,3'-triiodothyronine; T3) implemented to enhance the muscle and bone atrophy associated with simulated microgravity. Subsequently, the effects of countermeasures (alendronate and testosterone) administered to retard or reverse these T3 plus bedrest enhanced atrophic changes, were evaluated. Each participant was tested weekly for 5 weeks during Bedrest or non-bedrest (Up) conditions with the Neurobehavioral Evaluation System 2 (NES2), the Symptom Check List 90 Revised (SCL-90-R), and the Coping Responses Inventory (CRI).

Functional imaging during covert auditory attention in multiple sclerosis.

Recent literature suggests that the brain in multiple sclerosis (MS) undergoes reorganization that subserves the performance of visual and motor tasks. We identified sites of cerebral activity in 16 MS patients while performing a covert attention (CA) task, presented in the auditory modality. Positron emission tomography (PET) revealed activation of rostral/dorsal anterior cingulate cortex (ACC) in normal subjects studied previously.

Single-trial latency variability of auditory evoked potentials may indicate immediate memory in the albino rat.

Fast habituation (FH) is defined as a decrease in auditory evoked potential (AEP) amplitude in response to the second of a pair of temporally juxtaposed (e.g. 1-s) tones.

Covert auditory attention generates activation in the rostral/dorsal anterior cingulate cortex.

The anterior cingulate cortex (ACC) is believed to mediate conscious information processing or high-capacity attention. However, previous functional imaging studies have largely relied on tasks that involve motor function as well as attention. The work from our group utilizing an auditory continuous performance task demonstrated increased activity in a caudal division of the ACC that borders the supplementary motor area (SMA).