Background: Sustained attention problems and impulsivity are reported in association with prenatal alcohol exposure and fetal alcohol syndrome, but research in this area is limited and contradictory.
Methods: Auditory and visual sustained attention were investigated in 265 low-income, predominantly African-American, adolescents (mean age, 15.12 years; SD, 0.92). Included were 53 unexposed controls and 128 exposed to alcohol and other drugs prenatally, with 46 of these exhibiting dysmorphic features and growth retardation, as well as a special-education contrast group (n = 84). Sustained attention was measured with "AK" subtests from a commercially available Continuous Performance Task program. Outcomes included total correct, total errors, omissions, commissions, preservations, hit rate, false alarms, reaction time, and response sensitivity (d'). A repeated-measures multivariate analysis of variance procedure was used with the exposure group (four groups) as the independent variable and presentation mode (visual or auditory) and trial block (four blocks) as within-subject repeated measures.
Results: There was an interaction of group with presentation mode for total correct, errors, error type, hit rate, and d'. Most groups processed visual information more effectively than auditory information. In contrast, dysmorphic adolescents performed as effectively when presented with auditory stimuli but were less efficient in processing visual information. Significantly higher error rates, particularly omission errors [F(3,261) = 7.16; p < 0.000], as well as lower d' [F(3,261) = 5.77; p < 0.001], were noted in this group.
Conclusions: These results suggest that there may be specific patterns to the effect of prenatal alcohol exposure on cognitive performance that can be identified during adolescence. In this study of sustained attention, processing in the visual modality was more affected than that in the auditory modality. Deficits in visual processing seemed to result from insensitivity to target stimuli.