Retrieving something from my basement some years ago, I noticed movement in a corner. It was just a sense of something there, caught in a blink, if you will.

		"BLINK: THE POWER OF THINKING WITHOUT THINKING" By Malcolm Gladwell Little, Brown ($25.95)

By Malcolm Gladwell
Little, Brown ($25.95) Yet I knew instantly it was a rat. Within seconds, I was working on ways to get it out of my house. (I did, thanks to my dog and animal control officers.)

But, how did I, a person raised mostly in the suburbs where the nasty rodents are rare, grasp immediately that the brief glimpse of motion meant rat?

Experience and knowledge, explains Malcolm Gladwell in his foray into the still-murky world of neuroscience.

"First impressions are generated by our experiences and our environment," says the author of "The Tipping Point," the book about the spread of ideas that gained him attention in 2000.

I had seen a few live rats, but I remembered well the lurid illustrations from the children's book "The Pied Piper of Hamelin."

Somehow, that memory turned the almost invisible shadow in a dark cellar corner into a live and dangerous thing in a blink.

In a wide-ranging collection of anecdotes, Gladwell discusses our innate ability to make a decision, sense an outcome or size up a situation without lengthy pondering and gathering information.

Gladwell calls the process "thin-slicing," or how a small sampling of data is often enough to produce the right answer.

Curiously, autistic people lack the ability to intuit the emotions of others -- mind-reading, he calls it -- because they group faces with inanimate objects and miss the meaning of facial expressions.

In one of the most intriguing speculations in the book, Gladwell proposes that all of us can be guilty of "temporary autism," incidents when we completely misread the situation and react incorrectly.

His examples, though, are extreme, involving the reactions of police officers under stress, most notably the 1999 killing of Amadou Diallo in a hail of bullets fired by undercover New York cops.

The four white officers became "autistic" when facing a black man acting suspiciously in a high-crime neighborhood.

They were "blind," Gladwell says, and mistook the wallet in Diallo's hand for a gun.

Cops can be trained to appraise situations more accurately and objectively, he says.

"When our powers of rapid cognition go awry, they go awry for a very specific and consistent set of reasons, and those reasons can be identified and understood.

"Our snap judgments and first impressions can be educated and controlled. We can teach ourselves to make better snap judgments."

Studies and training programs are now under way to improve that education, including a system where police partners are being replaced by individual officers.

Apparently, well-trained people acting alone are better able to make good decisions when they are not influenced by others.

In fact, giving individuals wide freedom to act is one of the lessons of Gladwell's story of Paul Van Riper, a talented Marine officer whose innovations and creativity bedeviled the war-gamers at the Pentagon.

After learning how he blunted modern military technology and carefully drawn chains of command, it's easy to understand why peace in Iraq is so elusive under the Department of Defense.

Among Gladwell's collection of examples, ranging from taste-testing to predicting the success of marriages, is how thin-slicing can go wrong. He terms it the "Warren Harding Error."

Harding, an Ohio newspaper publisher and U.S. senator, cut a presidential figure with his white hair, booming voice and genial demeanor.

It didn't seem to matter that his long-winded speeches were full of generalities and forced alliterations or that his next-door neighbor was also his mistress.

But, he looked the part, hence his election in 1920 and also a prime example of how first impressions can go awry.

Today, the handsome Harding, who died in office, is considered one of the worst presidents in history.

Another valuable contribution is solid and scientific evidence that racism plays a major role in how people make judgments.

Gladwell's examples are fun, interesting and provocative and could lead some of his readers to trust their initial impressions with more conviction.

It's going to take more than snap judgments to understand the overall meaning of "Blink," however.

While he's a wide-ranging researcher and an engaging writer, he's not skilled enough to link his "experiments" into a unified whole.

His conclusion, "trust yourself," needs more than intuition to accept it.