Minds may track danger unconsciously.

Feelings of anxiety typically flood consciousness with a vivid sense of foreboding. However, those anguished feelings may originate in an unconscious mental process that anticipates real or imagined threats, according to a new study.

The investigation, which combines classical conditioning with brain wave measurements, broadly supports a theory of anxiety formulated 70 years ago by Sigmund Freud, contends psychologist Philip S. Wong of the New School for Social Research in New York.

"Some kind of unconscious signal function in the brain for anticipating danger situations must be a central feature of any comprehensive model of mind," Wong says.

Freud theorized that individuals unconsciously perceive dangerous situations resembling past traumas and recreate weaker, sometimes distorted versions of the past event to achieve a sense of control. Under these circumstances, feelings of anxiety act as a signal for help and trigger psychological defense mechanisms such as denial and repression, in Freud's view.

To explore unconscious processes involved in signal anxiety, Wong relied on a research design that uses classical conditioning. For instance, other investigators have found that people conditioned to expect a finger shock after seeing certain images exhibit rises in skin electrical conductance--an indication of heightened stress--upon viewing the same images flashed too quickly for conscious evaluation.

Wong fitted 17 men, all physically and mentally healthy, with sensors to monitor the brain's electrical activity. Participants first viewed a series of frowning faces presented subliminally so the researchers could determine baseline neural activity. Participants then saw a new set of frowning faces shown long enough for conscious perusal. A mild finger shock occurred 2 1/2 seconds after the appearance of each consciously discernable face.

Finally, the men watched subliminal presentations of the faces that had been linked to a shock, but this time they received no shock.

Distinct slow-wave brain activity emerged about half a second before the time at which shocks had been delivered in the conditioning phase, Wong reports in the current JOURNAL OF THE AMERICAN PSYCHOANALYTIC ASSOCIATION.

Prior studies indicate that this so-called "expectancy wave" arises when volunteers consciously anticipate making a planned movement or receiving a conditioned reward or punishment.

In the new study, the expectancy wave was elicited unconsciously, Wong says. It represents part of an unconscious danger-evaluation process, common to many animals, that underlies human anxiety responses, he proposes.

"These findings make a lot of sense in trying to understand danger assessment and the experience of fear and anxiety," remarks psychologist John A. Bargh of New York University. Bargh studies unconscious influences on attitudes and goals (SN: 10/30/99, p. 280).