Effects of prenatal tobacco, alcohol and marijuana exposure on processing speed, visual-motor coordination, and interhemispheric transfer

Abstract

Deficits in motor control are often reported in children with prenatal alcohol exposure (PAE). Less is known about the effects of prenatal tobacco exposure (PTE) and prenatal marijuana exposure (PME) on motor coordination, and previous studies have not considered whether PTE, PAE, and PME interact to affect motor control. This study investigated the effects of PTE, PAE, and PME as well as current drug use on speed of processing, visual-motor coordination, and interhemispheric transfer in 16-year-old adolescents. Data were collected as part of the Maternal Health Practices and Child Development Project. Adolescents (age 16, n=320) participating in a longitudinal study of the effects of prenatal substance exposure on developmental outcomes were evaluated in this study. The computerized Bimanual Coordination Test (BCT) was used to assess each domain of function. Other important variables, such as demographics, home environment, and psychological characteristics of the mother and adolescent were also considered in the analyses. There were significant and independent effects of PTE, PAE, and PME on processing speed and interhemispheric transfer of information. PTE and PME were associated with deficits in visual-motor coordination. There were no interactions between PAE, PTE, and PME. Current tobacco use predicted deficits in speed of processing. Current alcohol and marijuana use by the offspring were not associated with any measures of performance on the BCT.

Figure 1

Schematic of the target pathways and response box for the computerized Bimanual Coordination Test. The target paths appear on a computer screen and the response box sits on a table in front of the subject. The right knob on the response box controls vertical movement while the left knob controls horizontal movement. Bimanual performance on paths were grouped for analyses into those requiring (1) unimanual movement (0° and 90°), (2) symmetrical movement (both hands moving at the same rate, 45° and 130°), (3) Rightward dominant movement (right hand must move faster than the left, 67.5° and 112.5°), and (4) Leftward dominant movement (left hand must move faster than the right, 22.5° and 157.5°). Response time was recorded as the number of seconds to complete the path.