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David LaBerge has crafted a book on visual attention that will be accessible and interesting to a broad audience, from students doing their first project in cognitive psychology, to accomplished researchers in the field. The goal of the book is to present a coherent cognitive - neuroscience model of attention - a framework within which one can understand the rich database of findings pertaining to visual attention. In some respects, the book is also an overview and synthesis of LaBerge's own work on spatial attention. The first half of the book covers behavioural investigations; the second half covers cognitive - neuroscience investigations.
For scientists studying attention, it has been apparent for some time that distinctions must be made between different varieties of attention if progress is to be made in understanding this psychological phenomenon. In sections of the book which follow the initial overview and historical treatment, LaBerge wrestles with the diversities and similarities among different forms of attention, and arrives at his particular cut, developed formally in the Preparation/Selection model.
Preparatory attention is engendered by detailed expectations about a future event. Preparatory attention can be directed to a spatial location (e.g., left of center), to an attribute (e.g., upwards motion) or to an entire object (e.g., a car). For example, the expectation of a visual attribute, such as upwards motion, induces top - down preparatory activity in brain areas that specialize in sensory processing of that attribute. When the particular expected attribute appears in the visual field, preparatory attention facilitates its processing by speeding information flow.
Selective attention is engendered by the need to process a portion of a cluttered visual array. The purpose of selective attention is to route desired input for further processing and to attenuate undesired input. Both the degree of clutter and the similarity of the desired input to distracting input play prominent roles in LaBerge's analysis of selective attention.
These two varieties of attention, preparatory and selective, differ in terms of their spatial distribution and temporal performance. Preparatory attention is...