Spatial and non-spatial aspects of visual attention: Interactive cognitive mechanisms and neural underpinnings

In humans and non-human primates, the parietal lobe plays a key role in spatial attention - the ability to extract information from regions of space. This role is thought to be mediated by "priority" maps that highlight attention-worthy locations, and provide top-down feedback for motor orienting and attentional allocation. Traditionally, priority signals within the parietal cortex have been characterized as being purely spatial, i.e., encoding the desired locus of gaze or attention regardless of the context in which the brain generates that selection. Here, we highlight evidence from human behavior and neuroimaging as well as monkey physiology, to argue that non-spatial responses are critical to the establishment of priority maps in parietal cortex. This review offers an integrative view of the role that parietal cortex plays in attentional selection, providing evidence that priority maps reflect spatial and non-spatial priorities that ultimately act on sensory information in a spatial way.