Bridging Consciousness and Cognition in Memory and Perception: Evidence for Both State and Strength Processes

Abstract

Subjective experience indicates that mental states are discrete, in the sense that memories and perceptions readily come to mind in some cases, but are entirely unavailable to awareness in others. However, a long history of psychophysical research has indicated that the discrete nature of mental states is largely epiphenomenal and that mental processes vary continuously in strength. We used a novel combination of behavioral methodologies to examine the processes underlying perception of complex images: (1) analysis of receiver operating characteristics (ROCs), (2) a modification of the change-detection flicker paradigm, and (3) subjective reports of conscious experience. These methods yielded converging results showing that perceptual judgments reflect the combined, yet functionally independent, contributions of two processes available to conscious experience: a state process of conscious perception and a strength process of knowing; processes that correspond to recollection and familiarity in long-term memory. In addition, insights from the perception experiments led to the discovery of a new recollection phenomenon in a long-term memory change detection paradigm. The apparent incompatibility between subjective experience and theories of cognition can be understood within a unified state-strength framework that links consciousness to cognition across the domains of perception and memory.

Change detection on a hunch: Pre-attentive vision allows “sensing” of unique feature changes

“…According to Aly and Yonelinas (2012), "state-based" perception is a discrete perceptual state that does either occur or not occur, and that is accompanied by conscious perception of details of the changing object. By contrast, "strength-based" change detection can vary from weak to strong and is accompanied by a feeling of knowing that something has changed, but with little to no ability to identify what the change was.…”

“…By contrast, "strength-based" change detection can vary from weak to strong and is accompanied by a feeling of knowing that something has changed, but with little to no ability to identify what the change was. Using receiver operating characteristics, Aly and Yonelinas (2012) demonstrated that both types of perceptual judgments contribute independently to change detection performance. In later studies, the authors demonstrated that hippocampal damage impairs strength-but not state-based scene perception, and that hippocampal activation measured in fMRI correlates with strength-based, but not state-based perception (Aly et al, 2013a).…”

The Irrationality of Categorical Perception

“…Perception is often categorical (Harnard, 1987) and perceptual categorization can potentially affect decision making (Kiani et al, 2008;Aly and Yonelinas, 2012). Discrete categorization at the perceptual stage is at odds with the requirement that optimal decisions require evaluating the consequences of actions considering all possible states of the world-not just the state perceived.…”

“…This rule is similar to the Becker-DeGroot-Marshak mechanism in behavioral economics (Becker et al, 1964) and provides incentives for the subject to truthfully reveal a subjective probability p. For each of the 6 selected trials, subjects drew a ball from a bag of bingo balls labeled 1-100. If p Ͼ l 1 , the computer checked to see if the subject had correctly answered the relevant component of the task (selected direction for "Probability dots?," target acquisition for "Probability hit?," and overall success for "Probability overall?").…”

“…First, in tasks in which categorical perception has been reported, the utility function is most often implicit or fixed so as to preclude dissociating state inference from utility maximization: for example, observers may receive a reward for correctly reporting the world state and nothing otherwise. Second, whereas payoffs for different outcomes can be manipulated to affect decision criteria (Whiteley and Sahani, 2008;Feng et al, 2009;Fleming et al, 2010), this has mostly been examined in detection regimes in which the categorical aspects of perception are subtler (Kiani et al, 2008;Aly and Yonelinas, 2012). Finally, an important contributor to potential losses and gains from an action is the action itself (Trommershäuser et al, 2003a;Trommershäuser et al, 2003b;Körding and Wolpert, 2004;Trommershäuser et al, 2006;Landy et al, 2012), which in categorization and detection tasks is usually trivial (a button press or eye movement).…”