The stimulus response model of consumer behaviour is useful to understand the buying behaviour of individual consumers in the context of individuals buying consumer products. An extended stimulus-response model of behavioural processes in consumer decision making is proposed that serves to integrate the influences and interlinkages of buyer psychology, various buyer characteristics, and the impact of the buyer decision process on consumer decision making. The model proposes that the behavioural process of consumer decision making be as a result of the interaction of three aspects of individual buyer behaviour: communication sensitivity; enculturated individuality; and rational / economic decision making. The paper addresses the flip side of the consumer decision making process in terms of the five stages of decision making from need recognition to post-purchase satisfaction. An aggregate level framework of behavioural process in consumer decision making has been provided, that could lead to a richer analysis of micro level factors and relationships influencing consumer decision behaviour.