Consciousness is one of the most familiar phenomena in nature, but it is also one of the least understood.
What is the relationship between consciousness and the brain? Many theories have emerged in recent years, but there is no consensus. Led by project director Biyu Jade He from New York University Grossman School of Medicine as well as David Chalmers and Ned Block from New York University, this project aims to test two classes of theories of the brain basis of visual consciousness.
In first-order theories, visual consciousness involves a sensory representation of the external world, with a neural basis in the visual cortex. In higher-order theories, visual consciousness involves a higher-order representation of a sensory representation, with a neural basis in the prefrontal cortex. This project involves an adversarial collaboration between proponents of two leading higher-order theories of consciousness, the Higher-Order Representation of Representation theory (HOROR) and the Perceptual Reality Monitoring theory (PRM), and a leading first-order theory of consciousness, the Recurrent Processing Theory (RPT).
Theory leaders and team members have designed two experiments that attempt to falsify higher-order and first-order theories. Leaders of each theory have suggested an experimental paradigm that may falsify opposing theories by dissociating visual consciousness from its neural correlates according to those theories.
The experiments are designed to meet the high standards of open science. Whatever the result, this adversarial collaboration will lead to a higher level of rigor in the scientific study of consciousness and help narrow down the space of viable theories.
Change blindness is a phenomenon characterized by observers’ failure to notice seemingly obvious changes in their visual input. In most cases of change blindness in the literature, such unnoticed changes coincide with other visual transients. This research team studied slow change blindness, a related phenomenon that occurs even in the absence of visual disruptions when the change occurs sufficiently slowly, to determine whether it could be explained by conclusions from classic change blindness. Across three different slow change blindness experiments the team found that observers who consistently failed to notice the change had access to at least two memory representations of the changing display. One representation was precise but short lived: a detailed representation of the more recent stimulus states, but fragile. The other representation lasted longer but was fairly general: stable but too coarse to differentiate the various stages of the change. These findings suggest that, although multiple representations are formed, the failure to compare hypotheses might not explain slow change blindness; even if a comparison were made, the representations would be too sparse (longer term stores) or too fragile (short-lived stores) for such comparison to inform about the change.
