The role of perceptual- and semantics-related salience on working memory performance: Behavioral and fMRI studies

One of the most intriguing issues in the study of cognition is to understand which are the factors determining internal representation of the external world. Previous literature highlighted a key role played by attention selection mechanisms in biasing the access to memory representation. This is particularly true for common life situations, wherein scene complexity is such that only a sub-sample of stimuli can be processed efficiently. Here I will present a series of behavioral and neuroimaging (fMRI) studies based on visual search and delayed match-to-sample (i.e., working memory) tasks. In these tasks the to-be-searched and to-be-remembered targets were indexed by both low-level sensory salience and high-level semantics (e.g., the conceptual mismatch between the target and the context of the scene, or its emotional valence). Overall, the findings showed that both low- and high-level factors jointly contribute to guide attention selection and to enhance the probability of successful working memory encoding, through the selective involvement of the posterior parietal cortex.