As America prepares to vote in six days, a barrage of political ads will hit the airwaves, in addition to the countless ads and other news coverage most of us have already seen.
Barack Obama, who is running a half-hour primetime commercial on three networks tonight, is expected to spend a record $230 million on TV ads during the campaign. John McCain is expected to spend $130 million.
Those ads may influence voters' decisions more than they realize, according to psychological researchers who study the role of the subconscious mind on human behavior.
To demonstrate their theory to "Good Morning America," researchers Drew Westen and Joel Weinberger tested approximately 200 largely undecided voters across the country through a simple online test that measures implicit biases.
About half the test subjects were shown a picture of Obama and the other half a picture of McCain. Various words, both positive and negative, were flashed on the screen in different colors. The participants were asked to press a button that corresponded to the color of the word as it appeared on the screen.
The longer it takes a person to press the button, the more he or she associates that word with the candidate, according to Westen and Weinberger. And words that evoke fear are especially "sticky."
"We are more open to negativity, just our brain is. It's wired that way because we're wired to avoid threats more so than we're wired to go after positives," said Weinberger, a professor of psychology at Adelphi University in Long Island, N.Y.
The pre-frontal cortex, the part of the brain that controls rational thought, battles the unconscious brain when people make decisions, he said.
"You can be pulled in two levels by your gut," said Westen, a professor of psychology at Emory University in Atlanta. "One of them is that conscious feeling of this isn't how I should be voting, or this is how I should be voting. And another is just a gut level feeling that you're not even aware of."
Most of the voters in the study said ads calling McCain "out of touch" didn't affect their perception of him.
The same went for an Obama ad that suggested McCain was "erratic."
"I don't think it's so effective," said 31-year-old Andrew Darrow of Virginia, one of six people tested who appeared on "GMA."
But according to the test results, "Bush" and "erratic" were the top two words the group associated with McCain. On the positive side, "strong" and "fighter" were among the top five words they connected with the Arizona Republican.
The group was also shown a clip of a Sarah Palin rally where she said, "Obama, he pals around with terrorists."
The majority of voters said they didn't think Obama had any connection to terrorists.
But in fact, the word "terrorist" was one of the top five words the group associated with Obama.
One voter questioned the accuracy of the test.
"Are you sure this is foolproof?" said John Robilette, 64.
But another participant suggested that what people were saying in the group might not be what they were really thinking.
"Well, I don't know how honest we're all being," said Francine Harris, 53.
As for the loaded issue of race, most participants said Obama's race was not a factor in how they would vote.
But the No. 1 word they associated with Obama was "uppity," a word rife with racial overtones, which surprised the group members.
Those ads asking "who does he think he is" of Obama and characterizing him as arrogant may have planted themselves deeper in people's brains than they care to admit.
"It's in the back of your mind up until the day you go to that poll, and it's still going to be there when you're sitting there deciding, am I going to press this button or that button," Darrow said.
On the other hand, "calm" and "ready" were among the top words the group subconsciously associated with Obama.
Westen and Weinberger said based on positive versus negative associations with the candidates, the majority of the voters tested were leaning toward Obama, even if they didn't know it yet.
Find out more about Westen and Weinberger's work at Thinkscan.com.