In a 1974 study published in The Journal of Verbal Learning and Verbal Behavior, she asked participants to view films of fender-benders in which no car windows or headlights were broken. Later, the subjects who were asked how fast the cars were going when they “smashed” into each other — as opposed to “hit” — were more likely to report speeding and describe shattered glass they never actually saw.

In another experiment, conducted in Scotland, participants were four times as likely to report a memory of a nonexistent event — in this case, a nurse removing a skin sample from their little finger — if they had been asked to imagine it just one week before. Others in the experiment read a description, but were not asked to picture it happening.

Even the process of police questioning and prepping for trial can crystallize a person’s own faulty reconstruction. In 2000, Dr. Tversky published a series of experiments conducted at Stanford University in the journal Cognitive Psychology. In one, volunteers read profiles of fictitious roommates with both charming and annoying habits; they were then asked to write either a letter of recommendation or letter making a case for a replacement.

When later asked to repeat the original description, the volunteers’ recollections were skewed by the type of letter they had written. Their minds had shed qualities that didn’t match the first draft of their own recall and had embellished those that did.

“When we don’t remember, we make inferences,” Dr. Tversky said.

Sometimes we miss details because we weren’t paying attention, but sometimes we are concentrating too hard on something else. Nothing is as obvious as it seems.

Few experiments have demonstrated this more notably than one published in 1999 by researchers at Harvard. Participants watched a video of people dressed in either black or white passing a basketball. The subjects were told to count the number of passes made by players in white.