Method of searching for information in a database

1. A method to facilitate and optimize performing a search for information in a database, the method comprising the steps of:

presenting one item of data from a database at a time to an observer and measuring at least a physiological parameter of the observer;

in the absence of any variation in the physiological parameter greater than a predetermined threshold, and if the observer does not make any particular remarks, presenting at least one other item of data to the observer and measuring the physiological parameter of the observer;

in the presence of a variation in the physiological parameter greater than a predetermined threshold, detecting on an image at least one portion of interest to the observer and presenting an item of data having a relationship of similarity with the previously-presented data item, the relationship existing between the previously-presented image and the image presented after detecting a variation in the physiological parameter relating to said portion of interest; and

repeating all previous steps until at least one item of data from the database, which contains said information, is identified.

2. A method according to claim 1 , the method including a prior calibration step in which the physiological parameter is measured in order to determine a nominal level thereof.

3. A method according to claim 1 , wherein the portion of interest is detected by measuring the length of time said portion is examined.

4. A method according to claim 1 , wherein the portion of interest is detected by identifying a correlation between viewing said portion and the variation in the physiological parameter.

5. A method according to claim 1 , wherein the images are presented in groups, and wherein the method includes a step of detecting the observer's viewing direction while the images are being presented.

6. A method according to claim 1 , the method including a step of scoring the information that triggered the variation in the physiological parameter, during which the information is given a score that takes account of the degree of the observer's attention for the portrait and/or a characteristic of the variation in the physiological parameter.

7. A method according to claim 6 , wherein the presentation of information is interrupted when the score is greater than a predetermined threshold.

8. A method according to claim 6 , the method including a step of evaluating the reliability of the search by using at least one pre-established resemblance criterion to compare the items of information that have a score greater than a predetermined threshold.

9. The method according to claim 1 , wherein the database is a police database of possible suspects.