In this Masters' thesis project, I focused on how multisensory experiences influence later unisensory discrimination performance. Previous studies have provided evidence that single-trial multisensory experiences can influence the ability to accurately discriminate image repetitions during a continuous recognition task (Murray, et al., 2004; Murray et al., 2005; Lehmann and Murray, 2005). It has been shown that pairing visual objects with their corresponding sounds can enhance subsequent visual discrimination, whereas pairing visual objects with an identical pure tone leads to an impaired subsequent visual discrimination compared with performance with objects only encountered visually. Despite their opposing polarity, these effects indicate that incoming visual stimuli access multisensory memory traces established through single-trial learning. One open issue is the role of semantic versus episodic multisensory experiences, because prior work was confounded by pairing different visual objects with an identical pure tone (Lehmann and Murray, 2005). In the present masters' project, I determined the role of episodic multisensory experiences by pairing (on their initial encounters) visual objects with meaningless, but unique sounds. Subjects discriminated initial from repeated presentations of images of common objects. Half of the initial presentations of images were presented in a unisensory visual manner. Each of the remaining half of the images was paired on its initial presentation with a distinct but meaningless sound in a multisensory context. All repeated presentations were exclusively unisensory visual. The results of the psychophysical investigation showed that accuracy in recognition of repeated images was impaired for those that had been initially presented in a multisensory context. This decrement was dissociable from performance during initial image presentations, ruling out explanations in terms of attention or direct transfer from encoding to retrieval. Instead, the results indicate that the direction of the impact of single-trial multisensory memories on visual object discrimination is linked to the semantic versus episodic contingencies between the senses. The thesis is organized as follows. The first section will introduce multisensory learning and how this process impacts further unisensory discrimination and recognition performance. For this purpose several studies will be presented briefly. The second half of the introduction focuses on multisensory integration. The main principles of integration will be elucidated. Thereafter evidence supporting the model for early, low-level multisensory integration will be presented. The second section is build around the Master's project. The previous findings which led to the present investigation will be presented and the open questions will be illustrated. Subsequently, the submitted version of the manuscript which resulted from our psychophysical study is inserted. The third section is dedicated to the presentation of the ongoing electrical neuroimaging study. The preliminary results will be presented. Further future directions, in the form of a control experiment, will be presented.