There is a distinction between physiological and psychological aspects of addiction. Both of which are important for the development and maintenance of substance abuse. Within psychological aspects of addiction, attention and learning may play integral roles in substance abuse behaviour. This thesis explores how an environment seems to become increasingly occupied by substance-related stimuli, as a result of substance use (Chapter 5). It is demonstrated how such stimuli are able to initially attract attention (Chapter 2.6) and such attentional biases are difficult to inhibit (Chapter 2). Such attentional biases appear to be robust behaviours which are not overly affected by craving and outcome expectancies (Chapter 3). Moreover, it is discussed how attentional biases may be associated with automaticity development (Chapter 6). This research is performed using a dyslexic population, as dyslexia has been hypothesised as an impairment in automaticity development. Therefore a population potentially impaired in automaticity development may demonstrate different patterns of substance-related attentional bias, compared to control participants (Chapter 6.6). This means that a deeper understanding of how automaticity develops for some stimuli rather than others may be beneficial for the study of substance abuse (Chapter 7). Finally, it is suggested how substance abuse interventions may benefit from closer consideration of the attentional and learning aspects of addiction (Chapter 8).