The influence of levels of processing and attentional selection on the dynamics of visual awareness.
Research Project Objectives Both empirical results and theoretical accounts have provided contradictory answers to the question about the dynamics of the transition between unconscious and conscious processing of visual stimuli. On one hand, it was proposed that the transition is gradual, on the other hand, however, a number of studies suggested that there is a sharp threshold beyond which initially unconscious information becomes conscious. It seems plausible that both views might be true, because the dynamics of visual awareness might differ, depending on context or specific demands of a task at hand. The present project is focused on two factors that seem to play such a modulatory role in the transition from unconscious to conscious processing. The first factor is an actual level of processing (LoP) of visual information imposed by demands of a task, and the second factor is temporal attention. Proposed hypotheses state that these two factors modulate the graduality of the transition from unconscious to conscious vision in such a way that imposing either a high-level of processing of visual stimuli, or a strong attentional inhibition, decreases graduality of the transition. To test the hypotheses, six experiments were proposed, divided into two parts. The first part is focused on the levels of processing, and the second part is focused on attention.
Methodology The level of processing hypothesis will be tested in three experiments using three modifications of classic experimental paradigms to differentiate low and high levels of processing in terms of three different types of processes. The first experiment will employ Posner & Mitchell’s task, in which participants will be asked to classify letters, based on their physical identity, or on their semantic meaning. In the second experiment a mental rotation paradigm will be employed, to compare the subjective visibility of stimuli in the mental rotation task and in a simple recognition task. In the third experiment, the task will involve either identification, or a simple detection of stimuli. The attentional hypothesis will be tested using standard RSVP task, usually used to investigate temporal attention. The manipulations of the strength of inhibition, imposed by temporal attention, will be provided by changing difficulty of target identification in the experiment 4, by changing the similarity between target and distractor stimuli, in the experiment 5, and by adding simultaneous secondary task that should limit attentional recourses for the primary RSVP task. In all experiments, the subjective visibility of stimuli will be measured by means of a 4-point Perceptual Awareness Scale (PAS), which enables for fine assessment of graduality of visual awareness.
Expected impact The topic investigated in the project is one of the key research problems in current studies on the dynamics of visual awareness. Determining how the levels of processing and attentional selection influence the transition from unconscious to conscious processing should allow to clarify previous inconsistencies in the empirical results, and to integrate of the opposing theoretical concepts, as well as enables better understanding of the mechanism underlying the visual awareness.
Project under supervision of Michał Wierzchoń.