Subjective states associated with retrieval failures in Parkinson’s disease Celine Souchay a,⇑ , Sarah Jane Smith b a LEAD UMR CNRS 5022, Universite de Bourgogne, Esplanade Erasme, Pole AAFE, 21065 Dijon, France b Bradford Dementia Group, University of Bradford, UK article info Article history: Received 11 February 2013 Available online 30 May 2013 Keywords: Memory Subjective states Feeling-of-knowing Tip-of-the-tongue Parkinson’s disease abstract Instances in which we cannot retrieve information immediately but know that the infor- mation might be retrieved later are subjective states that accompany retrieval failure. These are expressed in feeling-of-knowing (FOK) and Tip-of-the-tongue (TOT) experiences. In Experiment 1, participants with Parkinson’s disease (PD) and older adult controls were given general questions and asked to report when they experienced a TOT state and to give related information about the missing word. The PD group experienced similar levels of TOTs but provided less correct peripheral information related to the target when in a TOT state. In Experiment 2, participants were given a Semantic (general knowledge questions) and an Episodic (word pairs) FOK task. PD patients failed to accurately predict their future memory performance (FOK) in response to both episodic and semantic cues. Results are interpreted in the context of recent frameworks of memory and metacognition. Ó 2013 Elsevier Inc. All rights reserved. 1. Introduction Parkinson’s disease (PD) is a neurodegenerative disorder characterized by motor symptoms, caused by a loss of dopami- nergic neurons in the basal ganglia. Studies investigating memory in PD have compared two main systems: the episodic memory system and the semantic memory system (Tulving, 1985). Episodic retrieval is characterized by a recollective expe- rience and a feeling of the self in the past (Tulving, 1985). Semantic retrieval is associated with noetic awareness (familiarity and knowing) and reflects conceptual knowledge. Studies in Parkinson’s disease have revealed impairments in episodic memory, particularly on free recall tasks (Daum et al., 1995; Gabrieli, Singh, Stebbins, & Goetz, 1996; Jonhson, Pollard, Vernon, Tomes, & Jog, 2005; Whittington, Podd, & Stewart-Williams, 2006; see Dujardin and Laurent 2003 for a review). Similarly, many studies have showed semantic memory deficits in Parkinson’s disease particularly on fluency tasks (see Henry and Crawford 2003 for a review). Whilst many researchers have suggested that memory problems in PD are associated with difficulties retrieving informa- tion, not many studies have actually explored the subjective states associated with retrieval in this clinical population. Sub- jective states differ according to the type of memory task involved (episodic versus semantic) as well as the retrieval outcome. Subjective states can either accompany retrieval success or emerge following a retrieval failure. In the case of a retrieval success, subjective states might be captured by the type of contextual information that participants can recall, such as where or when the information was presented (i.e. recollection). On the other hand, when people fail to retrieve the infor- mation they might infer that they still might retrieve the answer. Instances in which we cannot retrieve information imme- diately but know that the information will or might be retrieved later are the subjective states that accompany retrieval 1053-8100/$ - see front matter Ó 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.concog.2013.05.001 ⇑ Corresponding author. E-mail address: celine.souchay@u-bourgogne.fr (C. Souchay). Consciousness and Cognition 22 (2013) 795–805 Contents lists available at SciVerse ScienceDirect Consciousness and Cognition journal homepage: www.elsevier.com/locate/concog