Conscious Perception Can Be Both Graded And Discrete

Abstract

The Attentional Blink (Ab) Paradigm Has Been Used To Address An Enduring Debate About The Nature Of Conscious Perception: Does The Temporary Impairment In Conscious Perception Of The Second (T2) Of Two Serially Presented Targets Result From A Probabilistic All-Or-None Loss Of Information, Or Does T2 Transition Into Consciousness Along A Continuum Of Perceptual Fidelity? To Investigate This Question, We Presented Noisy Orientation Patterns As Targets Embedded In A Rapid Serial Sequence Of Nonoriented Noise Distractors, And Evaluated Perception Of T2 Orientation Using A Continuous Report Paradigm. Using Discrete Mixture Models And Variable Resource Models, We Evaluated The Effects Of Manipulating Both Perceptual And Central Demands On The Precision Of T2 Responses And The Estimated Frequency Of Random Guessing. When Perceptual Competition Between Targets Was Emphasized By Their Sharing Of A Common Visual Feature (I.E., Orientation), The Attentional Blink Was Associated With Degraded Precision Of T2 Perception. By Contrast, When The Task Required Switching Between Different Attended Features Across Two Visually Distinct Targets, T2 Awareness Was Impaired In An All-Or-None Manner As Evidenced By Significant Increases In Guessing Responses. Both Statistical And Model Comparison Analyses Indicated That Loss Of Target Information Can Be Graded Or Discrete, Depending On Whether Perceptual Or Higher Central Stages Are Taxed By Processing Demands. Our Findings Provide New Insights Into The Mechanisms Underlying The Attentional Blink And Help Reconcile Conflicting Views Regarding How Information Can Be Lost From Awareness