Event-related potentials dissociate perceptual from response-related age effects in visual search Iris Wiegand a,b, *, Kathrin Finke a , Hermann J. Müller a,c , Thomas Töllner a a Department of Psychology, Ludwig-Maximilians-Universität München, Munich, Germany b Graduate School of Systemic Neurosciences, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany c Department of Psychological Sciences, Birkbeck College, London, UK Received 5 February 2012; received in revised form 27 July 2012; accepted 2 August 2012 Abstract Attentional decline plays a major role in cognitive changes with aging. However, which specific aspects of attention contribute to this decline is as yet little understood. To identify the contributions of various potential sources of age decrements in visual search, we combined response time measures with lateralized event-related potentials of younger and older adults performing a compound-search task, in which the target-defining dimension of a pop-out target (color/shape) and the response-critical target feature (vertical/horizontal stripes) varied independently across trials. Slower responses in older participants were associated with age differences in all analyzed event-related potentials from perception to response, indicating that behavioral slowing originates from multiple stages within the information-processing stream. Furthermore, analyses of carry-over effects from one trial to the next revealed repetition facilitation of the target-defining dimension and of the motor response— originating from preattentive perceptual and motor execution stages, respectively—to be independent of age. Critically, we demonstrated specific age deficits on intermediate processing stages when intertrial changes required more executively controlled processes, such as flexible stimulus-response (re-)mapping across trials. © 2013 Elsevier Inc. All rights reserved. Keywords: Aging; Executive control; Visual search; Visual attention; Priming; Visual short-term memory; N2-posterior-contralateral; Contralateral-delay- activity; Lateralized-readiness-potential 1. Introduction One essential daily task that becomes slower with age is visual search: our ability to discern and react upon a visually more or less distinctive item in a cluttered scene (Madden et al., 2004). Age-related slowing in the performance of visual search tasks might be attributable to a selective stage in the information-processing cycle, or it might originate from several stages and accrue across the sequential processes making up the cycle. Candidate stages are the selection of task-relevant sensory information, the identification of re- sponse-critical information, and/or the selection and execu- tion of the required motor response (e.g., Kok, 2000; Salt- house, 2000). The present study was designed to examine this question at the microlevel of separable processing stages. Performance in visual search tasks is known to be influ- enced by recently encountered stimuli and actions per- formed in response to them, within a sequence of trial episodes (e.g., Maljkovic and Nakayama, 1994; Müller et al., 2010). A special instance that might pose particular problems for older adults is the remapping of previously encoded stimulus-response (S-R) associations across such episodes (Hommel et al., 2011). Presumably, the fast adap- tation processes involving flexible S-R remapping from one trial episode to the next require a higher degree of executive control processes, which are particularly age-sensitive (e.g., Park, 2000). * Corresponding author at: Department of Psychology, General and Ex- perimental Psychology, Ludwig- Maximilians-University Munich, Leopol- dstr. 13, D-80802 Munich, Germany. Tel.: +49 (0) 89 2180 72527; fax: +49 (0) 89 2180 5211. E-mail address: iris.wiegand@psy.lmu.de (I. Wiegand). Neurobiology of Aging 34 (2013) 973–985 www.elsevier.com/locate/neuaging 0197-4580/$ – see front matter © 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.neurobiolaging.2012.08.002