validities. Mroczek and Kolarz have also developed another set of scales to measure positive and negative affect. Each of the scales has 6 items. The scales have shown evidence of acceptable validity and reliability across cultures. Non-conscious affect and perception In relation to perception, a type of non-conscious affect may be separate from the cognitive processing of environmental stimuli. A monohierarchy of perception, affect and cognition considers the roles of arousal, attention tendencies, affective primacy (Zajonc, 1980), evolutionary constraints (Shepard, 1984; 1994), and covert perception (Weiskrantz, 1997) within the sensing and processing of preferences and discriminations. Emotions are complex chains of events triggered by certain stimuli. There is no way to completely describe an emotion by knowing only some of its components. Verbal reports of feelings are often inaccurate because people may not know exactly what they feel, or they may feel several different emotions at the same time. There are also situations that arise in which individuals attempt to hide their feelings, and there are some who believe that public and private events seldom coincide exactly, and that words for feelings are generally more ambiguous than are words for objects or events. Therefore, non-conscious emotions need to be measured by measures circumventing self-report such as the Implicit Positive and Negative Affect Test (IPANAT; Quirin, Kazén, & Kuhl, 2009). 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). But a note should be considered on the differences between affect and emotion. Arousal Arousal is a basic physiological response to the presentation of stimuli. When this occurs, a non-conscious affective process takes the form of two control mechanisms: one mobilizing and the other immobilizing. Within the human brain, the amygdala regulates an instinctual reaction initiating this arousal process, either freezing the individual or accelerating mobilization. The arousal response is illustrated