Ballesteros

Exp Brain Res (2008) 189:473–483 DOI 10.1007/s00221-008-1441-6

RESEARCH ARTICLE

Selective attention modulates visual and haptic repetition priming: effects in aging and Alzheimer’s disease
´ Soledad Ballesteros Æ Jose M. Reales Æ Julia Mayas Æ Morton A. Heller

Received: 14 February 2008 / Accepted: 25 May 2008 / Published online: 7 June 2008 Ó Springer-Verlag 2008

Abstract In twoexperiments, we examined the effect of selective attention at encoding on repetition priming in normal aging and Alzheimer’s disease (AD) patients for objects presented visually (experiment 1) or haptically (experiment 2). We used a repetition priming paradigm combined with a selective attention procedure at encoding. Reliable priming was found for both young adults and healthy older participants forvisually presented pictures (experiment 1) as well as for haptically presented objects (experiment 2). However, this was only found for attended and not for unattended stimuli. The results suggest that independently of the perceptual modality, repetition priming requires attention at encoding and that perceptual facilitation is maintained in normal aging. However, AD patients did not show primingfor attended stimuli, or for unattended visual or haptic objects. These findings suggest an early deficit of selective attention in AD. Results are discussed from a cognitive neuroscience approach. Keywords Alzheimer’s disease Á Aging Á Haptic repetition priming Á Selective attention Á Visual repetition priming

Introduction Studies on aging have shown robust declines in a number of cognitiveprocesses, including selective attention,
S. Ballesteros (&) Á J. M. Reales Á J. Mayas ´ ´ Facultad de Psicologıa, Universidad Nacional de Educacion a Distancia (UNED), Juan del Rosal, 10, 28040 Madrid, Spain e-mail: mballesteros@psi.uned.es M. A. Heller Eastern Illinois University, Charleston, IL, USA

processing speed, working memory and long-term episodic memory. By contrast, semanticknowledge, emotional processing and repetition priming is maintained in a stable form in old age (e.g., Craik and Salthouse 2000; Hedden and Gabrieli 2004; Park et al. 2001). Repetition priming refers to better performance with repeated presentation of stimuli. Responses to repeated stimuli are faster and more accurate than to non-repeated stimuli. Age invariance has usually been reported in visual primingstudies for words and pictures (e.g., Ballesteros et al. 2007b; La Voie and Light 1994; Light 1991; Mitchell 1989; Schacter et al.1992) and for objects presented haptically (Ballesteros and Reales 2004). Attention is required for episodic memory (e.g., Craik et al. 1996; Rock and Gutman 1981). However, the role of attention in repetition priming is not well understood. Some studies involvingdivided attention at encoding have reported priming for unattended stimuli. The lack of attention impaired performance on explicit and conceptual implicit memory tests and has little or no effect on perceptual implicit memory tests (e.g., Parkin and Russo 1990; Stankiewicz et al. 1998). A growing number of selective attention studies have reported attentional effects in both explicit and implicitmemory tasks (e.g., Ballesteros et al. 2006b; Ballesteros et al. 2007a; Crabb and Dark 1999; Hawley and Johnston 1991; MacDonald and MacLeod 1998). In a previous visual study with young adults (Ballesteros et al. 2006b) using the picture fragment completion test to assess repetition priming (experiments 1 and 2), we have consistently shown that pictures attended to at encoding were identified at alower completion level (i.e. better performance) than unattended and non-studied pictures. Moreover, priming was more pronounced and lasted longer (up to a month) for attended pictures. In experiment 3, priming was found for attended but not for unattended

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Exp Brain Res (2008) 189:473–483

pictures in a speeded object naming task. In a further study (Ballesteros et al. 2007a), we...