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General Information
Acacia is shorthand for the Amsterdam center for the study of adaptive control in brain and behavior. The center is based on a VICI award, granted by the Netherlands Organization for Scientific Research (NWO) to Prof. dr. Richard Ridderinkhof, and is stationed at the Department of Psychology of the University of Amsterdam. Launched in March 2005, the Acacia has become a center for research in the field of adaptive control from the perspective of the cognitive neurosciences. It features several PhD students, postdocs, research assistants, and senior researchers, plus many masters students from around the world.
Rather than a formal organizational unit at the University of Amsterdam, the Acacia is a virtual center, providing an avenue and financial support for the initiation, coordination, supervision, and dissemination of research. Thus, the Acacia fosters invited lectures, LabMeetings and JournalClubs, research tools and facilities, and conference trips for its associates, resulting in extensive collaborations within the center and with colleagues in the Netherlands and abroad. It thus provides a coordinative and organizational platform for numerous larger- and smaller-scale research projects. The virtual center is embodied in the present Acacia website.
The Acacia also has a public function in addition to its scientific mission. This dedicated public service aims at older adults in the Netherlands. Embodied in the website SeniorLab, its aim is to provide popular-scientific information for anyone interested in the field of neurocognitive aging, in particluar with respect to cognitive control. SeniorLab also lets older adults participate actively in experimental games and tasks, both on-line and as participants in our research projects.
Program Description
If circumstances call for immediate performance adjustments, how do neural interactions decide when to recruit cognitive control? How is adaptive decision making (deciding which action to take in the face of rapidly changing demands) established without invoking a homunculus?
- Medial frontal cortex (MFC) is involved in performance monitoring: evaluating outcome vis-à-vis expectancy, and detecting performance errors or conflicting response tendencies. MFC is not involved in implementing appropriate adjustments itself; this is the core business of prefrontal cortex (PFC), in particular lateral PFC and orbitofrontal cortex (OFC). There is some initial evidence for a direct contingency between performance monitoring and adaptive behavior. The specific mechanism by which detection of conflict or negative outcome in MFC engages the recruitment of control, however, remains undisclosed. How do PFC processes involved in implementing control become engaged when activations in MFC signal the need to instigate performance adjustments? Who is in command of recruiting cognitive control?
- This question, crucial to understanding adaptive cognitive control but thus far resistant to (if not exempt of) experimental scrutiny, is the main issue to be tackled in the intended research: what are the neurocognitive mechanisms that underlie the connections between signaling the need to increase the level of control (in MFC, indexed in EEG/fMRI measures), and the subsequent recruitment of control (in PFC, indexed in fMRI and behavioral adjustments, especially altered reaction-time distributions). Paradigmatic innovations and new combinations of methods will help scrutinize this missing link.
- Further explorations involve individual differences in these adaptive decision-making mechanisms related to old age. We will investigate the extent to which set shifting, goal-directed action selection, and performance monitoring involve differential patterns of activation among young and older adults. Correlations between age-differential brain activation patterns and specific aspects of behavioral decline will be examined to illuminate the risk-avoiding decision-making strategies associated with aging.