The influence of cognitive load and amount of stimuli on entropy through eye tracking measures

Entropy can be described qualitatively as a measure of energy dispersal. The concept itself is linked to disorder: entropy is a measure of disorder, and nature tends toward maximum entropy for any isolated system. One of the fields in which energy dispersal can be quantified is eye scanning in visual search. It is well known that visual research time in eye scanning is influenced by the number of targets to explore: the higher the number of targets, the longer the exploration time. The aim of this study is to understand whether the exploration time on non target stimuli depends on cognitive load and on the number of distracting stimuli. 26 voluntary students (mean age and standard deviation: 23.53 and 3.2) were involved in the study. Eye-Tracker technology was used with an intuitive and accessible graphic interface. The subjects were asked to detect and look at a target, as quickly as possible. During this task, in the first study subjects were also asked to listen to and repeat a list of numbers read aloud by an experimenter. In the second study distracting stimuli were manipulated by increasing their number. Results showed that both the amount of cognitive load and the number of distracting stimuli increase the entropy of eye movement. Results are discussed in terms of entropy theories.