Affective processes are involved in the formation and modification of attitudes toward a stimulus (Petty and Cacioppo, 1996).
- Advertising can work by creating feelings that can ultimately influence brand attitudes and behavior.

Consumers form their preferences on the basis of elements, such as liking, feelings, and emotions induced by the advertisements or familiarity triggered by mere exposure to the ad (Batra and Ray, 1986; Stuart et al., 1987; Janiszewski and Warlop, 1993).
- Ad-evoked feelings can become directly associated with the brand without any reasoning.

Attitudes toward the ad are related to the number of exposures to the ad (Pechman and Steward, 1989).
- Unfamiliar advertising messages take longer to reach their optimal effectiveness, while the effect of advertising also decreases after several exposures.

"Mere Exposure Theory" (Zajonc, 1968)
- Repeated exposure to a stimulus resulted in increased liking of the stimulus.
- There is an independent central nervous system network that is capable of generating affective responses without the participation of the consciousness-based autonomic nervous system.

Advertising and affective responses (Krugman, 1977; Rossiter and Percy, 1978)
- Advertising need not be informative to be effective, nor does it need to be verbal only, because emotional and visual elements can enhance the preference toward the ad.

Relationship between attitude toward the ad and attitude toward the brand (Mitchell and Olson, 1981)
- A positive reaction toward the ad is highly correlated with its brand preference.

Physiological Measurement (Ekman and Friesen, 1978; Bogart, 1996)
- In order to prevent cognitive bias in measuring the affective effects, a number of noncognitive methods, such as FACS (facial action coding system), EEG (electroencephalogram), pupil dilation, and brain wave, have been developed.