Emotion and memory for temporal information 1 Running head: EMOTION AND MEMORY FOR TEMPORAL INFORMATION 2005, Emotion, 5, 503-507

Contextual information such as color and spatial location has been found to be better remembered for emotional than for neutral items. The current study examined whether the influence of emotion extends to memory for another fundamental feature of episodic memory: temporal information. Results from a list discrimination paradigm showed that (a) item memory was enhanced for both negative and positive pictures compared to neutral ones, and was better for negative than for positive pictures; and (b) temporal information was better remembered for negative than for positive and neutral pictures, whereas positive and neutral pictures did not differ from each other. These findings are discussed in relation to the processes involved in memory for temporal information. Emotion and memory for temporal information 3 Influence of Emotion on Memory for Temporal Information There is now abundant evidence that memory for emotional events tends to be better than memory for neutral events (Reisberg & Hertel, 2004). In laboratory studies, individuals typically recall or recognize more emotional than neutral stimuli, whether they be words or pictures (see, e.g., Ochsner & Schacter, 2003; Phelps, 2004, for reviews). In addition, some studies using the Remember-Know procedure (Gardiner & Richardson-Klavehn, 2000; Tulving, 1985) suggest that the probability of being able to bring to mind some recollection of what occurred at the time an item was encoded is enhanced for emotional words (Dewhurst & Parry, 2000; Kensinger & Corkin, 2003) and pictures (Comblain, D’Argembeau, Van der Linden, & Aldenhoff, 2004; Ochsner, 2000), as compared to neutral ones. One does not know what participants in these studies actually remember about emotional stimuli, however. Memory for an item can include many kinds of information such as semantic features of the stimulus, information about the time and place at which it was acquired, its modality of presentation, associated thoughts and emotions, item parameters such as size and color, and so forth (Johnson, Hashtroudi, & Lindsay, 1993). A handful of recent studies have begun to investigate the effect of emotion on memory for some specific stimulus attributes. These studies show that features such as color information and spatial location are better remembered for emotional than for neutral items (D’Argembeau & Van der Linden, 2004; Doerksen & Shimamura, 2001; Kensinger & Corkin, 2003). However, the influence of emotion on memory for other stimulus attributes is currently unknown. In this study, we investigated the influence of emotion on memory for an essential characteristic of episodic memory: temporal information. A defining feature of episodic memory is indeed that events seem to belong to particular times in our past (Wheeler, Stuss, & Tulving, 1997). As is the case for other stimulus attributes, memory for temporal information seems to be more or less precise Emotion and memory for temporal information 4 depending on the retrieved item: we are able to recall the time of certain past events with great accuracy (e.g., one’s own wedding), whereas other events can be recalled but are difficult to locate precisely (e.g., the date when you bought a particular book). The purpose of this study was to investigate whether the emotional salience of an item affects our ability to localize the time at which it was previously encountered. To this end, a list discrimination paradigm (see, e.g., Parkin, Walter, & Hunkin, 1995) was used, in which participants were successively presented with three study lists, each containing positive, negative, and neutral pictures. For each study list, participants were asked to learn the pictures but were not informed that their memory for the list in which the item occurred would subsequently be tested (i.e., temporal information was encoded incidentally). This was done because previous findings suggest that the influence of emotion on memory for contextual information may in some cases be superseded by effortful encoding strategies (i.e., when participants voluntarily try to learn this information), at least for some types of contextual details such as color information (D’Argembeau & Van der Linden, 2004). Item memory and memory for temporal information were then assessed by asking participants to recognize the pictures among new ones and, contingent on recognition, to indicate whether they appeared in the first, second or third study list. Finally, as some studies have reported gender differences both in emotional response (e.g., Bradley, Codispoti, Sabatinelli, & Lang, 2001) and memory (e.g., Canli, Desmond, Zhao, & Gabrieli, 2002) for emotional pictures, we examined potential gender differences in the influence of emotion on item memory and memory for temporal information. Emotion and memory for temporal information 5