The Role of Feedback in Visual Attention and Awareness

Abstract

The mammalian visual system includes numerous brain areas that are profusely interconnected. With few exceptions, these connections are reciprocal. Anatomical feedback connections in general outnumber feedforward connections, leading to widespread speculation that feedback connections play a critical role in visual awareness. However, evidence from physiological experiments suggests that feedback plays a modulatory role, rather than a driving role. Here we discuss theoretical constraints on the significance of feedback's anatomical numerical advantage, and we describe theoretical limits on feedback's potential physiological impact. These restrictions confine the potential role of feedback in visual awareness and rule out some extant models of visual awareness that require a fundamental role of feedback. We propose that the central role of feedback is to maintain visuospatial attention, rather than visual awareness. Our conclusions highlight the critical need for experiments and models of visual awareness that control for the effects of attention. As a matter of clarity in this chapter: by “visual awareness” or “visibility” we mean the conscious perception that a stimulus is visible. Thus, for the purposes of this discussion, we use the terms visual awareness, visibility, and consciousness interchangeably.