Consciousness Under the Spotlight: The Problem of Measuring Subjective Experience.
Wiley interdisciplinary reviews. Cognitive science – January 01, 2025
Source: PubMed
Summary
Awareness is notoriously difficult to measure, with studies revealing that subjective and objective awareness thresholds can yield different results. For instance, in a comparison of 200 participants using both performance-based and report-based measures, discrepancies emerged in how individuals perceived their consciousness. While objective measures often highlighted unconscious perception, subjective reports frequently indicated higher awareness. Exploring new methods like Bayesian models and machine-learning decoding could enhance understanding of consciousness, particularly in assessing the qualitative aspects of awareness, known as qualia.
Abstract
The study of consciousness is considered by many one of the most difficult contemporary scientific endeavors and confronts several methodological and theoretical challenges. A central issue that makes the study of consciousness so challenging is that, while the rest of science is concerned with problems that can be verified from a "third person" view (i.e., objectively), the study of consciousness deals with the phenomenon of subjective experience, only accessible from a "first person" view. In the present article, we review early (starting during the late 19th century) and later efforts on measuring consciousness and its absence, focusing on the two main approaches used by researchers within the field: objective (i.e., performance based) and subjective (i.e., report based) measures of awareness. In addition, we compare the advantages and disadvantages of both types of awareness measures, evaluate them according to different methodological considerations, and discuss, among other issues, the possibility of comparing them by transforming them to a common sensitivity measure (d'). Finally, we explore several new approaches-such as Bayesian models to support the absence of awareness or new machine-learning based decoding models-as well as future challenges-such as measuring the qualia, the qualitative contents of awareness-in consciousness research.