The impact of reward and punishment on visual attention during naturalistic visual search: valence or salience?

In this thesis, I am going to address the issue of how both reward and punishment affect visual representation, by the use of a visual search paradigm performed in naturalistic scenes. More specifically, I am going to approach these two motivational forces by referring to their constituting dimensions, namely valence and salience. In fact, while being positioned in oppositely valenced space, these two outcomes share the burden of signaling stimuli with strong behavioral importance, coding therefore for motivational salience. After reviewing the main existing literature in this field (Chapter 1), I will describe a series of studies which examine how reward and punishment impact visual attention through the analysis of behavioral measures (Chapter 2) and fMRI activation (Chapter 3 and 4). The main idea resulting from these studies is that, in spite of what a rational approach to the problem would suggest, automatic visual attention does not process these two outcomes according to a salience, but rather through a valence pattern.