Dopaminergic modulation of cognition across the life span.

Half a century ago, dopamine (DA) was discovered as a neurotransmitter in its own right (see Björklund and Dunnett, 2007 for review). Since then, dopaminergic systems have been studied in the context of neuropsychiatric and other disorders (e.g., attention deficit hyperactivity disorder, schizophrenia, Parkinsonism and drug addiction), as well as from the perspectives of cognitive child development and aging. This broad interest in DA primarily reflects its important neuromodulatory functions in (a) subcortical and cortical neural networks, (b) a wide range of cognitive functions, and (c) age-graded changes in behavior across the lifespan. Compared to research on dopaminergic modulation of cognition in healthy young adults and various patient populations, investigations of the link between lifespan changes in DA systems and cognitive functions have been sparse. Hence, drawing evidence from studies of adolescents, younger and older adults, the present collection of review articles was assembled to promote research on the relations between changes in dopaminergic modulation and cognition across the lifespan (Bäckman et al., 2000, 2006; Li and Lindenberger, 1999; Li et al., 2001). The articles discuss recent empirical and theoretical progress in understanding the maturation and senescence of DA systems and their influences on cognition. They cover a wide methodological spectrum, ranging from behavioral studies and behavioral genetics over genomic imaging to pharmacological and neurocomputational approaches.