Mutual inhibition in collaborative recall: evidence for a retrieval-based account

In Experiment 1 participants gave 3 successive free recalls of items learned either individually or in pairwise collaboration. The first and third recalls were performed individually, the second alone or in collaboration. Collaborative recall led to an inhibitory effect after individual learning but not after collaborative learning, in which partners had similar retrieval strategies. Consistent with a retrieval locus for collaborative inhibition, non-recalled items reappeared in subsequent individual recall. Experiment 2 showed that collaborative inhibition was eliminated when a separate retrieval cue was given for each item. Experiments 2 and 3 also showed that when participants learned items in the same order, their retrieval strategies were more similar and they showed less collaborative inhibition. It is concluded that mutual interference in collaborative recall is due to the mutual disruption of individual retrieval strategies.     

Do novel associative word stem completion and cued recall share the same memory retrieval processes?

The aim of this study was to determine whether word stem completion for novel associations between cue and target words was mediated by automatic unconscious memory processes or effortful memory processes under conscious control. This was done by applying full and divided attention conditions at test to stem completion, cued recall, and recognition, and by administering a questionnaire that probed the memory strategies used by subjects during the completion test. Divided attention had no effect on stem completion performance, but did reduce associative cued recall. Recognition performance was weakened overall by divided attention, but the associative effect was similar under both attention conditions. This suggested that novel associative word stem completion was mediated by automatic retrieval processes. However, the results of the questionnaire indicated that only subjects who attempted to remember the words from the study phase during the completion task showed any novel associative effect. It is concluded that novel association word stem completion and cued recall share automatic retrieval processes, which nevertheless give rise to the experience of remembering.     

Effects of the timing and identity of retrieval cues in individual recall: an attempt to mimic cross-cueing in collaborative recall

Inhibitory effects in collaborative recall have been attributed to cross-cueing among partners, in the same way that part-set cues are known to impair recall in individuals. However, studies of part-set cueing in individuals typically involve presenting cues visually at the start of recall, whereas cross-cueing in collaboration is likely to be spoken and distributed over time. In an attempt to bridge this gap, three experiments investigated effects of presenting spoken part-set or extra-list cues at different times during individual recall. Cues had an inhibitory effect on recollection in the early part of the recall period, especially when presented in immediate succession at the start of recall. There was no difference between the effects of part-set and extra-list cues under these presentation conditions. However, more inhibition was generated by part-set than extra-list cues when cue presentation was distributed throughout recall. These results are interpreted as suggesting that cues presented during recall disrupt memory in two ways, corresponding to either blocking or modifying retrieval processes. Implications for explaining and possibly ameliorating inhibitory effects in collaborative recall are discussed.     

Priming of face matching in amnesia.

Priming was studied in a task that required a speeded response to photographs of faces. On each trial, subjects viewed two faces and decided if the same person was shown twice or if two different people were shown. Both familiar and unfamiliar (i.e., well-known and unknown) faces were used, and some face pairs were repeated with a mean delay of about 10 min. Repetition was associated with faster reaction times in young subjects (Experiment 1) as well as in amnesic patients and age-matched control subjects (Experiment 2). The patients' reaction times were slower overall, although the magnitude of the priming effect did not differ from that in the control subjects. This preservation of a normal reaction-time facilitation in subjects with impaired recognition memory for faces occurred for both familiar and unfamiliar faces, suggesting that amnesia does not necessarily interfere with the acquisition of new information as indexed by this priming effect.     

Do alcoholic amnesic patients passively rehearse verbal information?

Recently it has been claimed that alcoholic amnesic patients mainly engage in passive repetitive rehearsal during spontaneous learning and that this contributes to their memory problem. To test this hypothesis further, two experiments were conducted which compared list learning in amnesic patients and normal controls. In Experiment I both groups of subjects were required either to learn a list which was presented five times consecutively with free recall following each presentation, or they were asked to repeat each word out loud as they saw it and carry on doing so until the next word was shown. Five presentation trials were given and free recall was again tested after each presentation. It was predicted that if the amnesics' spontaneous form of learning involved only passive repetition there should be no difference between learning and repetition for this group while the controls should show an impairment in repeating compared to learning. The results showed that both groups of subjects were impaired to the same extent with repeating compared to learning and it was concluded that spontaneous learning was similar in both groups and that neither group merely passively rehearsed during spontaneous learning. A second experiment examined recognition performance of the two groups of subjects after learning or repeating lists of 20 words. Recognition was tested with distractors which were irrelevant, acoustically similar, graphemically similar, or semantically similar to the target word. It was found there were no differences between either of the groups in the pattern of errors made over the different distractor types. It was thus concluded that there was no encoding or rehearsal abnormality in the amnesic group. The possibility of differences between groups of alcoholic amnesics was discussed as well as the putative role of slow cognitive processing in their memory problems.     

Amnesics Have a Disproportionately Severe Memopry Deficit for Interactive Context

Two experiments were used to compare the recognition memory of amnesic and normal subjects for intentionally encoded words (targets) and for incidentally encoded words that were meaningfully related to the targets and presented at the same time (interactive context). In both experiments the target recognition of the two groups was matched at a high level by presenting the amnesics with much shorter lists of words to remember. Experiment 1 compared 20 amnesics and their matched controls and showed that whereas the amnesics' recognition of the target words did not benefit significantly when they were presented together with their interactive context words (relative to their recognition when the target words were presented alone), that of the controls did. Experiment 2 compared 14 amnesics and their matched controls and showed that when patients and their controls were matched on their target word recognition in isolation, then the patients still showed worse recognition for the interactive context words. These effects were not found only in Korsakoff patients, and their size did not correlate with behavioural measures of frontal-lobe damage. It is concluded that amnesics may be more impaired at recognizing incidentally encoded interactive context than they are at recognizing target material, and this deficit may be an essential feature of the syndrome.     

Effects of the timing and identity of retrieval cues in individual recall: An attempt to mimic cross-cueing in collaborative recall

Inhibitory effects in collaborative recall have been attributed to cross-cueing among partners, in the same way that part-set cues are known to impair recall in individuals. However, studies of part-set cueing in individuals typically involve presenting cues visually at the start of recall, whereas cross-cueing in collaboration is likely to be spoken and distributed over time. In an attempt to bridge this gap, three experiments investigated effects of presenting spoken part-set or extra-list cues at different times during individual recall. Cues had an inhibitory effect on recollection in the early part of the recall period, especially when presented in immediate succession at the start of recall. There was no difference between the effects of part-set and extra-list cues under these presentation conditions. However, more inhibition was generated by part-set than extra-list cues when cue presentation was distributed throughout recall. These results are interpreted as suggesting that cues presented during recall disrupt memory in two ways, corresponding to either blocking or modifying retrieval processes. Implications for explaining and possibly ameliorating inhibitory effects in collaborative recall are discussed.     

The Claparède phenomenon: A further example in amnesics,a demonstration of a similar effect in normal people with attenuated memory,and a reinterpretation

Three amnesics and four controls were asked to find hidden objects in cartoon drawings, and their success rate and search speed were noted over five learning trials. When latency on the first trial was equated in the two groups, amnesics were shown to learn the location of the test objects less rapidly than controls. Savings scores at seven weeks were similar in the two groups when amount of exposure during learning was equivalent. At seven weeks amnesics failed to recognize items that they were able to show savings on in terms of speed of search (the Claparede phenomenon), but a similar effect was demonstrated in the control group when tested some 17 months later. The implications of the results for various retrieval-deficit views of the amnesic syndrome were discussed.     

Are two heads better than one? Experimental investigations of the social facilitation of memory

The hypothesis that two people collaborating in recall would remember more than a single person was examined in a series of four experiments. All the experiments used variations on the same ‘sequential’ design where, in social conditions, people recalled alone initially and then recalled jointly in pairs: as a control for reminiscence, some people recalled alone on two separate occasions. On the second recall in all of the experiments two people always recalled more than one, but this was simply due to the independent statistical summation of two people's memories: no evidence whatsoever was found for the pairs of people generating new information that was not available to either member of the pair. This surprising result was not attributable to artefacts linked to the complexity or familiarity of stimulus material, nor was it linked to variations in people's cognitive perspectives. No evidence of social facilitation of memories was therefore found: two people recalling together certainly pool their separate memories so as to outperform individuals but the social interaction does not appear to generate previously unavailable memories.