  The role of attention in cognition becomes obvious if we take into  account the fact that the mere coming together of object, sense  faculty, and consciousness is not sufficient for a cognitive event to arise. Rather, cognition occurs only when consciously attending to a  given object. In normal circumstances, the senses always process a  steady and continuous stream sensory impressions. But this sense data becomes a concrete object of apprehension only when attention is  directed toward specific regions of the perceptual field. Why is it  that causation must be understood from the perspective of  consciousness? Because, given the generally pragmatic concerns of the Buddhist explanatory account, consciousness is central to effecting  the changes that are necessary for an individual engaged on the noble eight-fold path to make any real progress. Thus, whereas contact  cannot be prevented so long as consciousness (citta)  inhabits, and is conditioned by, the mental constituents  (caitta, caittasika), feelings and perceptions that result from contact are within the purview of consciousness.