Attention, perceptual continuity, and action control

Visual perception is based on much more than retinal input. One striking example of this is the way information from the motor system about body, head and eye movements is smoothly and effortlessly incorporated into our perception of the visual environment. The image on the retina is in almost constant motion as a consequence of our own movements, but perception is subjectively stable and continuous, and we rarely confuse changes on the retina caused by our own movements with changes due to objects moving in the environment, or lose track of objects as eye movements shift them rapidly from one place to another on the retina.

On the other hand, visual perception is also based on far less than retinal input. More information falls on our retina than we can process, so some selection is necessary. Although it may feel like perception incorporates the entire scene in equivalent detail, this is because we find detail wherever and whenever we look for it. But, like the refrigerator light, when we are not looking for it, it does not exist. Without attention, we seem to process the world in a rudimentary state, one in which objects have no continuity or identity. Unattended objects in the environment can be swapped, removed, and changed without perturbing our visual experience. But what does attention do that imbues our environment with detail, identity, meaning and continuity? Despite decades of dedicated research, the field of cognitive psychology is still only scratching at the surface of this question.

Our recent work on the first issue has begun to shed light on the second. Spatial attention seems to play a critical role in perceived stability across eye movements. Just before an eye movement, evidence is growing that activity in visual maps in the brain corresponding to attended objects will shift across the map in order to remain aligned with the object’s expected new position on the retina. The result of this shift of attention is a continuous perception of attended objects across saccades. This model is an important addition to our understanding of perceptual continuity across saccades, and it also sheds new light on old questions about the nature of visual attention, and the role of attention in eye movements and in action more generally. In current and future research I am exploring the idea that predictive shifts of attention provide the basis not only for perceptual continuity, but also for comparing the expected sensory consequences of eye movements with their actual consequences. I am also interested in understanding the extent to which conclusions about the role of attention in eye movement control that we build from remapping can apply to actions more generally, or to any kind of predictable environmental changes. Re‐examining attention in light of its role in perceptual continuity and eye movement control holds great promise for reshaping our understanding of its fundamental properties and function.