The quality of perception without attention

Abstract

Although we experience a rich and detailed world every time we look around, we do not have the capacity to report about all that we experienced if the scene is taken away. Our limited attentional capabilities restrict us to only report about the few items that we happened to attend to. Does this imply that we are never conscious of more than a few items at once? Or should our definition of consciousness include the unattended part of our perceptual experience? The discussion about whether we consider a certain process as conscious or unconscious depends for an important part on definition. In this thesis, I provide data to inform this discussion. I first determined that we can study unattended stimuli behaviorally by examining different stages in visual short-term memory. I then examined whether certain characteristics that are associated with consciousness - such as information integration that support perceptual inference and explicit information processing - are present for these different stages of memory. Last, I looked at the neural signature of unattended stimuli to investigate whether the same type of perceptual processing occurs as for attended stimuli. In sum, I found that unattended processes display many of the characteristics that we normally associate with attended processing. Below, I will first summarize and interpret the main findings of this thesis, and then discuss what this might imply for the study of consciousness