Predictive eyes precede retrieval : visual recognition as hypothesis testing

Abstract: Does visual recognition entail verifying an idea about what is perceived? This question was addressed in the three studies of this thesis. The main hypothesis underlying the investigation was that visual recognition is an active process involving hypothesis testing. Recognition of faces (Study 1), scenes (Study 2) and objects (Study 3) was investigated using eye movement registration as a window on the recognition process. In Study 1, a functional relationship between eye movements and face recognition was established. Restricting the eye movements reduced recognition performance. In addition, perceptual reinstatement as indicated by eye movement consistency across study and test was related to recollective experience at test. Specifically, explicit recollection was related to higher eye movement consistency than familiarity-based recognition and false rejections (Studies 1-2). Furthermore, valid expectations about a forthcoming stimulus scene produced eye movements which were more similar to those of an earlier study episode, compared to invalid expectations (Study 2). In Study 3 participants recognized fragmented objects embedded in nonsense fragments. Around 8 seconds prior to explicit recognition, participants began to fixate the object region rather than a similar control region in the stimulus pictures. Before participants’ indicated awareness of the object, they fixated it with an average of 9 consecutive fixations. Hence, participants were looking at the object as if they had recognized it before they became aware of its identity. Furthermore, prior object information affected eye movement sampling of the stimulus, suggesting that semantic memory was involved in guiding the eyes during object recognition even before the participants were aware of its presence. Collectively, the studies support the view that gaze control is instrumental to visual recognition performance and that visual recognition is an interactive process between memory representation and information sampling.