Neuropsychologia 44 (2006) 1388–1397 Differential components of prospective memory? Evidence from fMRI Jon S. Simons a,∗ , Marieke L. Sch ¨ olvinck a , Sam J. Gilbert a , Chris D. Frith b , Paul W. Burgess a a Institute of Cognitive Neuroscience and Department of Psychology, University College London, UK b Wellcome Department of Imaging Neuroscience, Institute of Neurology, University College London, UK Received 14 October 2005; received in revised form 22 December 2005; accepted 11 January 2006 Available online 28 February 2006 Abstract Two of the principal components of prospective memory (i.e., remembering to carry out delayed intentions) are recognizing the appropriate context to act (“cue identification”) and remembering the action to be performed (“intention retrieval”). In this experiment, the demands on these components were manipulated while measuring brain activity using fMRI to explore whether the two components share a common neural basis. The results showed significant behavioral differences between the cue identification and intention retrieval conditions. However, a consistent pattern of hemodynamic changes was found in both prospective memory conditions in anterior prefrontal cortex (BA 10), with lateral BA 10 activation accompanied by medial BA 10 deactivation. These effects were more pronounced when demands on intention retrieval were high. This is consistent with the hypothesis that anterior prefrontal cortex (area 10) supports the biasing of attention between external events (e.g., identifying the cue amid distracting stimuli) and internal thought processes (i.e., maintaining the intention and remembering the intended actions). Together, the results suggest that whilst cue identification and intention retrieval may be behaviorally separable, they share at least some common neural basis in anterior prefrontal cortex. © 2006 Elsevier Ltd. All rights reserved. Keywords: Anterior prefrontal cortex; Rostral prefrontal cortex; Frontal lobes; Functional magnetic resonance imaging (fMRI); Executive function 1. Introduction Prospective memory (PM 1 ), remembering to perform an intended action after a delay (Meacham & Singer, 1977), may involve a number of processing stages: forming an intention, maintaining the intention in memory over an interval while being engaged in another (or ongoing) task, executing the intended action at the appropriate moment, and evaluating the outcome (Freud, 1901; Ellis, 1996). Much research into PM has focused on the third of these stages, involving recogni- tion of the appropriate moment to act and remembering what action was to be performed (see Table 1 in Burgess, Scott, ∗ Corresponding author at: Brain Mapping Unit, University of Cambridge, Addenbrooke’s Hospital, Hills Road, Cambridge CB2 2QQ, UK. E-mail address: jss30@cam.ac.uk (J.S. Simons). 1 Delegates at the 2nd International Conference on Prospective Memory, Zurich, July 2005, voted that the use of the abbreviation “PM” for prospective memory was preferable to other extant forms. & Frith, 2003, for a list of cardinal properties of PM). The most often studied example is where an action needs to be per- formed when an external event occurs, such as remembering to stop and buy a loaf of bread when you drive past the gro- cery store (“event-based PM”; Einstein, Holland, McDaniel, & Guynn, 1992). McDaniel and Einstein (1992) proposed a division of event-based PM into two components: cue identi- fication and intention retrieval. Cue identification involves the detection of the cue event (e.g., the grocery store) signaling that the intended action should be performed; intention retrieval involves the subsequent recovery of that intention (e.g., buy- ing the bread) from memory. There are a considerable number of behavioral studies that have investigated these components (e.g., Brandimonte & Passolunghi, 1994; Cohen, West, & Craik, 2001; Marsh, Hicks, Cook, Hansen, & Pallos, 2003; Einstein et al., 1992; Einstein, McDaniel, Manzi, Cochran, & Baker, 2000; Ellis & Milne, 1996; West, Herndon, & Crewdson, 2001; West & Ross-Munroe, 2002; West, Wymbs, Jakubek, & Herndon, 2003). 0028-3932/$ – see front matter © 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.neuropsychologia.2006.01.005