sentence: On the other hand , it has been suggested that associations between tactile stimuli and chroma decline with age : Ludwig and Simner ( 2013 ) found significant associations between chroma and tactile properties in children but not adults , suggesting innateness of associations ( cf ., neonatal synaesthesia ; Maurer & Mondloch , 2005 ) , which is lost during development through processes such as neural pruning.One modality for which the developmental trajectory of crossmodal associations has not been as well studied is olfaction .