ABSTRACT
In recent years an increasing trend can be observed to utilize eye movements as an empirical basis for models of cognitive activity. In order to interpret a fixation as an attentive response to some information in the display, it is necessary to separate the informational units on display by a distance that exceeds the functional visual field. Care should be taken to exclude the possibility that peripheral visual processing alone would allow sufficient access to the stimulus information. Instead of defining a fixation as an inter-saccadic period of relative rest, the external size of the informational unit constitutes the frame of a fixation. The hypothesis testing strategy was inferred indirectly by comparing the observed behavior with the prediction of formalized models. The eye movements were analyzed in the same way as before except that those periods where the experimenter gave his statement were eliminated.
