At the time of writing (December, 2013), a search for cognitive bias modification (CBM) in SCOPUS yields 113 results. Tellingly, the earliest of the articles found by this rather crude search appear in 2009, clustering around the special issue on CBM in the Journal of Abnormal Psychology that year (Koster et al. 2009). While the term CBM had been used in the literature prior to this, and in fact research into CBM (albeit not always using this exact term) had been steadily gathering momentum since the first studies were published in 2000, there has clearly been an explosion in research on CBM in the years since. What has happened in this period? Over the past 4 years, CBM research has been on an exciting journey, with many twists and turns, ups and downs. This special issue seeks to provide an overview of this journey, and a glimpse of the road-or roads-ahead. But where to begin? The journey did not start in 2009, nor even a decade earlier when the dominant CBM paradigms were first described. To fully make sense of this journey, and all the twists in this travellers' tale, we must go back further still.Once upon a time … during the cognitive era of psychology … researchers embarked on the great adventure of exploring the 'cognitive landscape' of emotional pathology … an extremely challenging landscape…. After a few years, the first landmarks were established: cognitive biases in emotional disorders. But what did they signify? It seemed that such selective information-processing biases were crucial factors in the etiology, maintenance, and relapse of various types of emotional disorders. Hence, many cognitive theories built on this discovery in order to account for emotional pathology (e. Cognitive biases reflect a general processing advantage for disorder-relevant information. The findings of cognitive-experimental research indicate that emotional disorders are (roughly) characterized by three types of biases, i.e., biases in attention, interpretation, and memory. To illustrate, depressed or anxious individuals are, compared to healthy individuals, more likely to attend to negative cues, interpret ambiguity in a more negative manner, and selectively recall negative information (for a review, see Mathews and MacLeod 2005). According to the assumptions put forward by cognitive theories, the functional relationship between biases and emotional pathology can be described as follows: Biases are accompanied by various dysfunctional cognitions, which in turn activate dysfunctional emotional and behavioral responses. Due to the reinforcing connection between cognitions, emotions, and behavior, a 'psychopathological downward spiral' becomes activated in vulnerable individuals, possibly resulting in anxiety-or depression-related symptoms.In parallel to the development of measures to assess biases in attention, interpretation, and memory, researchers started to investigate whether it is also possible to modify biased cognitive processes. This work was motivated by the question of the causal nature of these biases: while the...