Affective responses, on the other hand, are more basic and may be less problematic in terms of assessment. Brewin has proposed two experiential processes that frame non-cognitive relations between various affective experiences: those that are prewired dispositions (i.e. non-conscious processes), able to "select from the total stimulus array those stimuli that are causally relevant, using such criteria as perceptual salience, spatiotemporal cues, and predictive value in relation to data stored in memory" (Brewin, 1989, p. 381), and those that are automatic (i.e. subconscious processes), characterized as "rapid, relatively inflexible and difficult to modify... (requiring) minimal attention to occur and... (capable of being) activated without intention or awareness" (1989 p. 381).