Empirical factors affecting memory in collaborative versus nominal groups.

When individuals collaborate to try to retrieve some encoded information, not surprisingly, the collaborative group typically remembers more than does any individual. When the non-redundant output from the individuals is combined, however, this nominal group often, surprisingly, remembers more than does the collaborative group. This finding is known as collaborative inhibition. The finding of collaborative inhibition, that collaborative groups remember less would be predicted given the summed non-redundant memories of an equal number of individuals remembering alone, indicates that there is something about remembering in a collaborative group that impairs the performance of the individuals in that group. Research directed toward what that something is has focused on both social and cognitive factors, with the consensus being that cognitive factors play the more important role. An extensive body of work on this topic has accumulated over the past 25+ years, with researchers proposing theoretical explanations and generating empirical data revealing the conditions under which this collaborative inhibition is more versus less likely to occur. The purpose of this review is to summarize those empirical factors to provide a resource for researchers interested in pursuing this work.

Task Interference in Prospective Memory: Adopting a Retrieval Mode and Checking for Targets.

Embedding a prospective memory task in an ongoing activity can interfere with performance of that ongoing activity. One explanation of this task interference is that it entails (a) adopting a retrieval mode or readiness to encounter the targets that indicate when to perform the intended action and (b) checking the environment for those targets. An experiment using a new method is reported and provides evidence for these processes. On control trials, participants performed just the ongoing activity (a short-term memory task combined with a 4-choice RT task). On experimental trials, a prospective memory task (press the Enter key if certain words appear in the short-term memory task) was embedded in the ongoing activity. Evidence for adopting a retrieval mode came from finding slower RT task performance on control trials when participants had already been instructed about the prospective memory task than when they had not yet been so instructed. Evidence for target checking came from finding slower RT task performance on experimental trials when a target could appear in any one of five locations than in just one location.

Emotional display rules in Palestine: Ingroup/outgroup membership, status of interaction partner and gender.

This study investigates emotional display rules within the Palestinian context, focusing on the seven basic emotions in a sample of 150 college students from the Gaza Strip and the West Bank. Overall, participants felt that it was more appropriate to express positive emotions (happiness and surprise) than negative powerful (anger, contempt and disgust) or negative powerless (fear and sadness) emotions. They also perceived it to be more appropriate to express positive and negative powerless emotions to ingroup than outgroup members and to express negative powerful emotions to lower status compared to higher status individuals. Gender differences were also found: men endorsed greater expression of both powerful and, surprisingly, powerless emotions than women, but only when interacting with outgroup members. Results are interpreted in terms of the cultural values of individualism-collectivism and power distance as well as cultural differences in emotional expressiveness between collectivistic societies. This study is one of the first to examine emotional display rules in an Arab population, thus expanding our current knowledge base.

The Future Orientation of Past Memory: The Role of BA 10 in Prospective and Retrospective Retrieval Modes.

Klein made the provocative suggestion that the purpose of human episodic memory is to enable individuals to plan and prepare for the future. In other words, although episodic (retrospective) memory is about the past, it is not actually for the past; it is for the future. Within this focus, a natural subject for investigation is prospective memory, or memory to do things in the future. An important theoretical construct in the fields of both retrospective memory and prospective memory is that of a retrieval mode, or a neurocognitive set or readiness to treat environmental stimuli as potential retrieval cues. This construct was originally introduced in a theory of episodic (retrospective) memory and has more recently been invoked in a theory of how some prospective memory tasks are accomplished. To our knowledge, this construct has not been explicitly compared between the two literatures, and thus this is the purpose of the present article. Although we address the behavioral evidence for each construct, our primary goal is to assess the extent to which each retrieval mode appears to rely on a common neural region. Our review highlights the fact that a particular area of prefrontal cortex (BA 10) appears to play an important role in both retrospective and prospective retrieval modes. We suggest, based on this evidence and these ideas, that prospective memory research could profit from more active exploration of the relevance of theoretical constructs from the retrospective memory literature.

Relational and item-specific influences on generate-recognize processes in recall.

The generate-recognize model and the relational-item-specific distinction are two approaches to explaining recall. In this study, we consider the two approaches in concert. Following Jacoby and Hollingshead (Journal of Memory and Language 29:433-454, 1990), we implemented a production task and a recognition task following production (1) to evaluate whether generation and recognition components were evident in cued recall and (2) to gauge the effects of relational and item-specific processing on these components. An encoding task designed to augment item-specific processing (anagram-transposition) produced a benefit on the recognition component (Experiments 1-3) but no significant benefit on the generation component (Experiments 1-3), in the context of a significant benefit to cued recall. By contrast, an encoding task designed to augment relational processing (category-sorting) did produce a benefit on the generation component (Experiment 3). These results converge on the idea that in recall, item-specific processing impacts a recognition component, whereas relational processing impacts a generation component.

Target preexposure eliminates the effect of distraction on event-based prospective memory.

Prospective memory is critical to everyday functioning and can be vulnerable to distraction. We conducted an experiment to explore whether we could buffer prospective memory against distraction. For half the participants, we preexposed stimuli that were later designated as prospective memory targets. Then, all participants performed an ongoing task (in which the prospective memory task was embedded) under standard and high attentional demand (i.e., under full and divided attention). Target preexposure improved prospective memory and eliminated the significant divided attention effect. Thus, target preexposure seems to buffer prospective memory against the disruptive effect of dividing attention. Moreover, target preexposure seemed to help participants to respond with the correct intended action. This result implies that preexposure to the target stimuli facilitated the encoding of an association between the target stimuli and the intended action, perhaps promoting relatively more reflexive retrieval and thereby buffering prospective memory against distraction.

Brain regions and their dynamics in prospective memory retrieval: a MEG study.

We measured brain activity using magnetoencephalography in five participants during ongoing tasks that included prospective memory, retrospective memory, and oddball trials. Sources were identified in the hippocampal formation and posterior parietal and frontal lobes. Posterior parietal cortex activation had an earlier onset in the prospective memory condition than retrospective memory or oddball conditions, a higher level of theta activity in the retrospective condition, and higher levels of upper alpha in the prospective and oddball conditions. Activation of the hippocampal formation had a longer duration in the retrospective memory and prospective memory conditions than the oddball condition, but prominent alpha and theta band activity was present in all three conditions. We interpret the early (87 ms) onset of activity in parietal cortex as evidence for an initial noticing of appropriate conditions for a PM response. Hippocampal activity may reflect a subsequent memory search for the intended action.

The role of noticing in prospective memory forgetting.

Two experiments used autonomic reactions (i.e., skin conductance responses; SCRs) in conjunction with behavioral responses to study retrieval processes in prospective memory. SCRs were recorded while participants performed a prospective memory task embedded in an ongoing task. Stimuli that received the same behavioral response (i.e., no prospective memory response) evoked different autonomic reactions as a function of whether they were versus were not prospective cues (Experiments 1 and 2) and as a function of whether they did versus did not share perceptual or conceptual features with prospective cues (Experiment 2). To the extent that SCRs provide an index of noticing a stimulus, increased SCRs for prospective cues and for stimuli that shared features with prospective cues (even though they were not responded to as prospective cues) provided evidence that noticing a stimulus is not invariably accompanied by recognizing the stimulus as a cue to perform an intended action. The results are consistent with the general 2-stages cue-focused view of prospective memory retrieval, which proposes that noticing a prospective cue prompts a directed memory search, which can result in recognizing the stimulus as a cue to perform an intended action and retrieving the intended action.

Disentangling encoding versus retrieval explanations of the bizarreness effect: implications for distinctiveness.

Recall effects attributed to distinctiveness have been explained by both encoding and retrieval accounts. Resolution of this theoretical controversy has been clouded because the typical methodology confounds the encoding and retrieval contexts. Using bizarre and common sentences as materials, we introduce a paradigm that decouples the nature of the encoding context (mixed vs. unmixed lists of items) from the retrieval set (mixed vs. unmixed retrieval sets). Experiment 1 presented unmixed lists for study, and Experiment 2 presented mixed lists for study. In both experiments, significant bizarreness effects were obtained in free recall when the retrieval set intermixed items but not when the retrieval set consisted of only one item type. Also, Experiment 1, using a repeated testing procedure, did not reveal evidence for more extensive encoding of bizarre sentences than of common sentences. The results support the idea that retrieval dynamics primarily mediate the bizarreness effect, and perhaps more generally, distinctiveness effects.

Apolipoprotein E and prospective memory in normally aging adults.

The epsilon4 allele of apolipoprotein E (APOE) is an established risk factor for Alzheimer's disease, despite uncertainty as to its effect on cognitive function in normal aging. Some evidence suggests poor episodic memory and executive functioning in epsilon4 allele carriers. Prospective memory has been overlooked in investigations of the relationship between APOE and cognition. The authors used a laboratory paradigm to examine the relationship between prospective memory and APOE status in healthy elderly adults, and they varied the association (high vs. low) between a target word and a response word. The authors found a significant deficit in prospective memory for epsilon4 allele carriers but no effect of association in either group. The results suggest the deficit was due to failure of the prospective component of the task.

Cue-focused and reflexive-associative processes in prospective memory retrieval.

Several theories of event-based prospective memory were evaluated in 3 experiments. The results depended on the association between the target event and the intended action. For associated target-action pairs (a) preexposure of nontargets did not reduce prospective memory, (b) divided attention did not reduce prospective memory, (c) prospective memory was better than when the target event and intended action were not associated, and (d) prospective memory was characterized by retrieval of the precise intended action. These results converge on the view that retrieval is mediated by a reflexive-associative process. In contrast, for unassociated pairs (a) preexposure of nontargets reduced prospective memory, and (b) divided attention reduced prospective memory. These results implicate cue-focused retrieval processes and are most consistent with a discrepancy-plus-search model. The entire pattern implicates both cue-focused and reflexive-associative processes and more generally supports a multiprocess framework of prospective memory (M. A. McDaniel & G. O. Einstein, 2000).

Goal specificity and knowledge acquisition in statistics problem solving: evidence for attentional focus.

Solving training problems with nonspecific goals (NG; i.e., solving for all possible unknown values) often results in better transfer than solving training problems with standard goals (SG; i.e., solving for one particular unknown value). In this study, we evaluated an attentional focus explanation of the goal specificity effect. According to the attentional focus view, solving NG problems causes attention to be directed to local relations among successive problem states, whereas solving SG problems causes attention to be directed to relations between the various problem states and the goal state. Attention to the former is thought to enhance structural knowledge about the problem domain and thus promote transfer. Results supported this view because structurally different transfer problems were solved faster following NG training than following SG training. Moreover, structural knowledge representations revealed more links depicting local relations following NG training and more links to the training goal following SG training. As predicted, these effects were obtained only by domain novices.