Perceptual integration without conscious access.

The visual system can integrate fragmented input into organized surfaces and objects, a process called perceptual integration. Whether this requires conscious access was tested using the attentional blink, which impairs conscious perception. Behaviorally, the attentional blink reduced accurate conscious decisions about integrated surface structure. Yet, multivariate EEG decoding showed the brain still represented integrated percepts even when conscious access was blocked. In contrast, masking impaired both conscious decisions and neural decoding of integration, while leaving feedforward signals intact. These findings indicate that perceptual integration can occur without access to consciousness, dissociating the two processes.

Study at a glance

Abstract

The visual system has the remarkable ability to integrate fragmentary visual input into a perceptually organized collection of surfaces and objects, a process we refer to as perceptual integration. Despite a long tradition of perception research, it is not known whether access to consciousness is required to complete perceptual integration. To investigate this question, we manipulated access to consciousness using the attentional blink. We show that, behaviorally, the attentional blink impairs conscious decisions about the presence of integrated surface structure from fragmented input. However, despite conscious access being impaired, the ability to decode the presence of integrated percepts remains intact, as shown through multivariate classification analyses of electroencephalogram (EEG) data. In contrast, when disrupting perception through masking, decisions about integrated percepts and decoding of integrated percepts are impaired in tandem, while leaving feedforward representations intact. Together, these data show that access consciousness and perceptual integration can be dissociated.