Lana Okubo^1,2 (), Shin'yα Nishida¹, Kiyofumi Miyoshi¹; ¹Kyoto University, ²Japan Society for the Promotion of Science

Scholars have long debated the relationship between attention and consciousness. An important challenge is explaining how we maintain coherent conscious experience across the entire visual field, despite that attention can only be allocated to specific locations or features. We propose that this is achieved through the concurrent operation of two attention-related phenomena: (1) attentional boosting, in which an attended stimulus appears more intense when compared to an unattended stimulus, and (2) subjective inflation, in which a stimulus can paradoxically become more detectable under inattention when tested in yes/no detection. Using the signal detection theory (SDT) framework, we demonstrated that these seemingly conflicting phenomena can indeed occur simultaneously under the identical set of parameter values. Specifically, we conducted an SDT simulation of comparative judgment between two stimuli (relevant to attentional boosting) and yes/no detection of a stimulus (to examine subjective inflation). Evidence from each stimulus was assumed to be normally distributed across trials. The critical assumption was that attention (attended vs. unattended) modulates both the mean and variance of evidence distributions. Following our previous findings, we posited that attended stimuli are encoded with higher mean strength and reduced variance, whereas unattended stimuli are represented with lower mean strength and increased variance. Importantly, these encoding regimes interacted with each task’s demands, simultaneously accounting for both phenomena. In yes/no detection, increased variance in the unattended condition raised the probability of a weak stimulus producing evidence exceeding the threshold, providing a mechanistic explanation for subjective inflation. In contrast, variance showed a limited impact on comparative judgment, and the elevated mean of attended compared to unattended distributions yielded the typical attentional boosting effect. Our computational perspective bridges classical attention theory with contemporary consciousness research, showing how our visual system prioritizes specific locations while maintaining broadly stable perception by preserving stimulus visibility in unattended areas.

Acknowledgements: This work was supported by JSPS KAKENHI Grant Number 24KJ0137 and 25K00896.