For this study, researchers examined the emotional response of 60 healthy young adults, 18 to 27 years of age, to environmental cues. The participants were divided into two groups of 30 (15 males, 15 females): those with a positive paternal history of alcoholism (FH+), and those without (FH-). All participants were interviewed and completed self-reports in order to create a personal, psychological and alcohol-history profile, and had their eye-blink electromyogram (EMG) activity to acoustic startle probes measured while viewing 36 color photographs. Following the latter procedure, participants rated the photographs as pleasant, neutral or unpleasant.
The FH- group showed a normal linear increase in the eye-blink EMG component of the startle reflex, with response strength increasing from the pleasant to neutral to unpleasant photographs. In contrast, the FH+ group did not show the typical increase of eye-blink EMG to the unpleasant photographs.
"The findings suggest that FH+ individuals may have a deficit in their aversive motivational system or AMS that might lead them not to learn to moderate their drinking so that they avoid the negative consequences of drinking," said Peter R. Finn, associate professor of psychology at Indiana University. "The theoretical rationale runs something like this: an under-responsiveness to the aversive photographs is associated with a relative weakness, or reduced st