Cornering the unconscious.

Suppose you want to find out what an acquaintance really thinks about you. Your best bet might be to ask one of your friends and one of your enemies to query the acquaintance about his or her feelings toward you. Then you can estimate the acquaintance's true attitude by comparing the rosy comments delivered to your friend -- undoubtedly boosted by social pressure -- with the positive comments expressed to your enemy, which likely underestimate actual friendly feelings.

This strategy guides a new approach to teasing out conscious from unconscious influences on memory and perception, described in the June AMERICAN PSYCHOLOGIST by psychologist Larry L. Jacoby of McMaster University in Hamilton, Ontario, and his co-workers. "It's an important advance," remarks psychologist John F. Kihlstrom of the University of Arizona in Tucson.

Kihlstrom and other researchers typically chart unconscious influences by contrasting explicit and implicit forms of memory and perception. Explicit tests tap conscious knowledge, as when volunteers try to identify previously studied words on a multiple-choice test; implicit tests reveal unconscious influences of memories or perceptions, as when volunteers unwittingly complete ambiguous word fragments with previously studied words.

But many investigators acknowledge that conscious recollections or perceptions at least partly boost scores on implicit tests.

"Just as gaining a true measure of friendship requires bad times as well as good times, a measure of unconscious influences requires separate conditions in which unconscious processes oppose and act in concert with the aims of conscious intention," Jacoby says.

The Canadian psychologist devised such a measure to confirm a prior study in which volunteers who were distracted while reading a list of concocted names later rated many of them as famous when shown a new list containing the same names, new nonfamous names, and famous names. Unconscious familiarity with previously read names apparently produced "false fame" judgments, Jacoby theorizes. In the new experiment, he first gave participants a conscious opportunity to reject the influence of unconscious familiarity by telling them that the earlier read names were not famous. This "opposition test" corresponds to a known enemy questioning an acquaintance, Jacoby says.

Experimenters then told the volunteers that another list of previously read names came from "obscure" famous people, thus putting conscious recollection and unconscious familiarity "in concert" -- similar to an acquaintance being questioned by a known friend.

To estimate the extent of volunteers' conscious recollections for names, Jacoby subtracted the probability of making "false fame" judgments on the opposition test from that on the in-concert test. With this measure, he calculated the contribution to false fame responses made by unconscious familiarity.

The results: Dealing with distractions while reading names radically reduced conscious recollection, but false fame judgments soared. Undisturbed study of the names reversed this pattern.

Manipulations of attention apparently open the door to particularly strong unconscious influences, Jacoby asserts. For example, background music accompanied by audible lyrics pitching a commercial product probably leaves people open to far more unconscious persuasion than a "subliminal" sales message hidden in the same music, he contends.