Contingent negative variation in the fetal alcohol syndrome: a preliminary report

This study investigates contingent negative variation (CNV) in ten children diagnosed as fetal alcohol syndrome (FAS) and ten control children whose mothers reported only infrequent drinking during pregnancy. Cortical potentials were obtained using a procedure similar to Cohen's (1976) design. Stimuli consisted of a randomly presented flash followed 1.5 sec later by a tone. Sixty-four trials were presented with tone offset under experimenter control. For the next 128 trials, the subject pushed a button to turn off the tone. The EEG was recorded from Cz, P3, and P4 referred to linked earlobes. In addition, a resting EEG was obtained prior to the start of the trials. Cortical potentials were averaged separately over the two sets of trials and measures of slope and integrated amplitude obtained. Preliminary analysis showed that four of ten FAS children had negative slopes while eight of ten control children had negative slopes. These differences between groups, while in the predicted direction, were not statistically significant. Additional analyses are in progress.