Challenging research in various fields has driven a wide range of methodological advances in variable selection for regression models with high-dimensional predictors. In comparison, selection of nonlinear functions in models with additive predictors has been considered only more recently....

Functional magnetic resonance imaging (fMRI) is the most popular technique in human brain mapping, with statistical parametric mapping (SPM) as a classical benchmark tool for detecting brain activity. Smith and Fahrmeir (J Am Stat Assoc 102(478):417–431, <CitationRef CitationID="CR22">2007</CitationRef>) proposed a competing method based...</citationref>