OCULOMOTOR INDICATORS OF INORGANIC LEAD NEUROTOXICITY.
Item
-
Title
-
OCULOMOTOR INDICATORS OF INORGANIC LEAD NEUROTOXICITY.
-
Identifier
-
AAI8205754
-
identifier
-
8205754
-
Creator
-
GLICKMAN, LINDA A.
-
Contributor
-
Jose A. Valciukas | Wilfred A. Gibson
-
Date
-
1982
-
Language
-
English
-
Publisher
-
City University of New York.
-
Subject
-
Psychology, Physiological
-
Abstract
-
Many experiments have demonstrated that chronic exposure to inorganic lead is associated with adverse effects on the central nervous system. The effects range from morphological changes in selective brain regions, particularly the cerebellum, to interference with central neurotransmitters. In addition, recent investigations have shown that chronic, low level exposure to inorganic lead can result in subtle central nervous system dysfunction including clinical symptoms, decrements on neuropsychological test scores and possibly oculomotor disorders.;The primary purpose of this study was to investigate the effects of chronic, low-level exposure to inorganic lead on quantitative measures of saccadic eye movements. The association between oculomotor response measures and biological indicators of lead absorption such as level of blood lead and zinc protoporphyrin was also examined.;Subjects were 52 lead-exposed automobile production workers and 52 controls with no history of occupational exposure to neurotoxic agents. Subjects were required to fixate five lights appearing in semi-random order in the horizontal plane. An infrared system was used to record saccadic eye movements. This was connected to an inkwriting physiograph equipped with a DC-AC and a differentiator coupler. The differentiator provided the mathematical derivative of the analog signal voltages. In this way the amplitude and maximum velocity of saccadic eye movements were recorded.;Four characteristics of eye movements were studied: (1) total number, (2) number of saccades to fixate the visual targets; (3) number of overshoots; and (4) the relationship between the amplitude and maximum velocity.;The results indicated that individuals exposed to inorganic lead showed statistically significant differences on three of the measures of eye movements studied (total number, saccades-to-target, and overshoots) compared to controls. A significant group by age interaction was observed for total number of eye movements. In addition, both total number of eye movements and the number of saccadic eye movements to fixate the targets were significantly correlated with both level of blood lead and zinc protoporphyrin. The numerical values found to characterize the amplitude-velocity relationship were not correlated with blood lead levels, but a highly significant correlation was observed between this response measure and zinc protoporphyrin level.;The findings of the present study demonstrate that exposure to inorganic lead can affect the oculomotor system, leading to disturbances both in the ability to move the eyes from one stationary point in the visual field to the next, and in the maximum velocity of saccadic eye movements. The outcome of this study also points to the value of quantitative assessment of measures of saccadic eye movements as an early indicator of central nervous system changes due to exposure to inorganic lead.
-
Type
-
dissertation
-
Source
-
PQT Legacy CUNY.xlsx
-
degree
-
Ph.D.
-
Program
-
Psychology
