Cognition and Neurosciences Effects of pair collaboration and word-frequency in recognition memory: A study with the remember-know procedure CLELIA ROSSI-ARNAUD, 1 LAURA PIERONI, 1 PIETRO SPATARO 2 and VINCENZO CESTARI 3 1 Department of Psychology, University of Rome ‘‘Sapienza’’, Italy 2 Department of Dynamic and Clinical Psychology, University of Rome ‘‘Sapienza’’, Italy 3 Department of Educational Sciences, LUMSA University and CNR Institute, Rome, Italy Rossi-Arnaud, C., Pieroni, L., Spataro, P. & Cestari, V. (2011). Effects of pair collaboration and word-frequency in recognition memory: A study with the remember-know procedure. Scandinavian Journal of Psychology 52, 516–523. The present study investigated the effects of pair collaboration and word-frequency on recognition memory, using the ‘‘remember-know’’ procedure. The aim was to test the predictions of the information-exchange hypothesis (Clark, Hori, Putnam & Martin, 2000), which states that collaborative facilitation occurs when participants are able to share their recollective memories with other members of the group. Results showed that recognition performance was significantly better in the collaborative than in the individual condition, and better for low-frequency than for high-frequency words. The advantage of col- laborating dyads was produced by an increase of correct hits, coupled with a significant reduction of false alarms. Furthermore, the analysis of the ‘‘remem- ber’’ (R) and ‘‘know’’ (K) responses indicated that the effects of both pair collaboration and word-frequency were larger on recollection than on familiarity processes. It is concluded that, in a collaborative condition, arguments based on the retrieval of the contextual details associated with the target words are more effective than those based on familiarity in increasing the proportions of correct hits. In addition, it is proposed that collaboration may lead to a reduction of the probability to accept new items on the basis of familiarity (K) responses. Key words: Collaboration, recognition memory, frequency, recollection. Clelia Rossi-Arnaud, Department of Psychology, University ‘‘Sapienza’’, Rome, Via dei Marsi 78, 00185, Italy. Tel: + 39 06 49917513; fax: + 39 06 49917711; e-mail: clelia.rossi-arnaud@uniroma1.it INTRODUCTION Explicit memory can be assessed via recall or recognition, either individually or in a group. Although it is generally accepted that people collaborating remember more than individuals (Lorge & Solomon, 1961; Meudell, Hitch & Boyle, 1995), Weldon and Bel- linger (1997) demonstrated that the total number of items retrieved by collaborative groups was lower than the recall of non-collaborative (nominal) groups, which are created by pooling responses of individuals working alone, with redundant stimuli counted only once. This effect, typically observed in free recall with groups of two (Andersson & Ro ¨nnberg, 1996; Finlay, Hitch & Meudell, 2000; Wright & Klumpp, 2004) or three subjects (Basden, Basden, Bryner & Thomas, 1997; Weldon & Bellinger, 1997), is called collaborative inhibition. A number of mechanisms have been advanced to account for the decrease in recall performance of collaborative groups, ranging from motivational factors, such as social loafing or evaluation apprehension (Weldon, Blair & Dearmin, 2000), to cognitive pro- cesses, like production blocking or strategy disruption (Basden et al., 1997; Finlay et al., 2000; Wright & Klumpp, 2004). In par- ticular, the latter hypothesis states that listening to the collabora- tors’ output would disrupt individual retrieval strategies. The underlying assumption is that, when subjects are requested to recover stored information in a free recall task, each of them for- mulates a systematic strategy that specifies the order of recollec- tion of the target items. However, in a collaborative condition participants are simultaneously exposed to the stimuli produced by other members of the group, which have an organization usually inconsistent with that of individual retrieval schemes. Therefore, it follows that using someone else’s output to cue one’s own mem- ory will often have negative effects, inducing participants to switch from their spontaneous retrieval order towards less effective strategies (Basden & Basden, 1995; Basden et al., 1997). In contrast to the inhibitory effect observed in free recall, Clark et al. (2000; see also Clark, Abbe & Larson, 2006) showed that collaboration at retrieval can facilitate performance in recognition tasks, primarily by increasing hit rates. To explain the difference between their results and those obtained by Weldon and Bellinger (1997), Clark et al. (2000) proposed that recognition may mini- mize the role of the retrieval-blocking mechanisms that are hypoth- esized to be at the origin of collaborative inhibition in free recall. Indeed, in recognition tasks the target words are re-presented at retrieval, so that group members are not required to use list-based retrieval strategies to impose their own order on recall, and thus are less open to mutual disruption. Rather, an increase in hit rates only requires that a person makes a compelling argument for why she/he is correct about the judgement of an item as old, for exam- ple by invoking specific recollections (Clark et al., 2000, 2006). Although collaborative facilitation in recognition memory is now well established, to date no study has examined the locus of this effect. More specifically, results from cognitive, neuropsycho- logical and neuroimaging research indicate that performance in recognition tasks reflects two distinct processes, referred to as rec- ollection and familiarity (for a review see Yonelinas, 2002). Even if different models have been proposed, all of them share the basic notion that recollection responses require the retrieval of the con- textual details associated with the study events. For instance, Mandler (1980) proposed that familiarity reflects an increase in stimulus activation, whereas recollection implies a search process Ó 2011 The Authors. Scandinavian Journal of Psychology Ó 2011 The Scandinavian Psychological Associations. Published by Blackwell Publishing Ltd., 9600 Garsington Road, Oxford OX4 2DQ, UK and 350 Main Street, Malden, MA 02148, USA. ISSN 0036-5564. Scandinavian Journal of Psychology, 2011, 52, 516–523 DOI: 10.1111/j.1467-9450.2011.00912.x