Quality space computations for consciousness

The quality space hypothesis holds that conscious sensory states, such as colors, are experienced in relation to one another—red feels more like orange than like green or blue. Recent evidence indicates that subjective similarity among experiences can be explained by similarities in neural activation patterns. This review examines how localist, workspace, and higher-order theories of consciousness can account for the qualitative character of experience and functionally support a quality space. Existing empirical evidence for each theoretical position is assessed, and novel experimental methods—including altering local activation spaces through brain stimulation or behavioral training—are highlighted as ways to distinguish among these accounts.

Study at a glance

Abstract

The quality space hypothesis about conscious experience proposes that conscious sensory states are experienced in relation to other possible sensory states. For instance, the colour red is experienced as being more like orange, and less like green or blue. Recent empirical findings suggest that subjective similarity space can be explained in terms of similarities in neural activation patterns. Here, we consider how localist, workspace, and higher-order theories of consciousness can accommodate claims about the qualitative character of experience and functionally support a quality space. We review existing empirical evidence for each of these positions, and highlight novel experimental tools, such as altering local activation spaces via brain stimulation or behavioural training, that can distinguish these accounts.