Hypermnesia occurs in recall but not in recognition

Two experiments investigated the effect of encoding conditions and type of test (recall vs. recognition) on the phenomenon of hypermnesia (improved performance across repeated tests). Subjects in Experiment 1 studied a list of words using either imaginal or semantic elaboration strategies and then received three successive tests. Different groups of subjects received either free recall, four-alternative forced-choice recognition, or yes/no recognition tests. Reliable hypermnesia was found only in the recall conditions, with the recognition conditions showing either no change in performance levels across tests (forced-choice tests) or significant forgetting (yes/no tests). In Experiment 2, subjects studied a list of words, and encoding was manipulated using three orienting tasks. Once again, hypermnesia was found with the recall tests but not with the forced choice recognition tests. Finding hypermnesia in recall but not in recognition indicates that retrieval processes in recall play a major role in producing hypermnesia. Also, the finding that the magnitude of the recall hypermnesias increased with an increase in total cumulative recall levels across study conditions suggests that cumulative recall levels are an important factor in determining the presence or absence of recall hypermnesia.     

Hypermnesia in free recall and cued recall

In three experiments, categorized lists and both free recall and cued recall tests were used to examine hypermnesia. In Experiment 1, materials were drawn from obvious and nonobvious categories in an attempt to vary the amount of relational processing at encoding. The study materials in Experiment 2 consisted of a long word list that comprised several exemplars from each of a number of common categories. In Experiment 3, a single exemplar was drawn from each of 45 categories. In each experiment, similar magnitudes of hypermnesia were obtained on free and cued recall tests. Examination of the specific items recalled across tests indicated that similar processes underlie the hypermnesic effect for both test conditions. Implications of the results for extant accounts of the hypermnesic effect are discussed. It is concluded that the dynamics of retrieval processes change in a systematic fashion across repeated tests and the retention interval following study and that an adequate account of the nature of these changes in retrieval dynamics is essential to our understanding of hypermnesia and related phenomena.     

Hypermnesia: Age-related differences between young and older adults

Hypermnesia is a net improvement in memory performance that occurs across tests in a multitest paradigm with only one study session. Our goal was to identify possible age-related differences in hypermnesic recall. We observed hypermnesia for young adults using verbal (Experiment 1) as well as pictorial (Experiment 2) material, but no hypermnesia for older adults in either experiment. We found no age-related difference in reminiscence (Experiments 1 and 2), though there was a substantial difference in intertest forgetting (Experiments 1 and 2). Older, relative to young, adults produced more forgetting, most of which occurred between Tests 1 and 2 (Experiments 1 and 2). Furthermore, older, relative to young, adults produced more intrusions. We failed to identify a relationship between intrusions and intertest forgetting. We suggest that the age-related difference in intertest forgetting may be due to less efficient reinstatement of cues at test by older adults. The present findings reveal that intertest forgetting plays a critical role in hypermnesic recall, particularly for older adults.     

Classification accuracy across multiple tests following item method directed forgetting

We investigated recall of line-drawing pictures paired at study with an instruction either to remember (TBR items) or to forget (TBF items). Across three 7-minute tests, net recall (items reported independent of accuracy in instructional designation) and correctly classified recall (recall conditional on correct instructional designation) showed directed forgetting. That is, for both measures, recall of TBR items always exceeded recall of TBF items. Net recall for both item types increased across tests at comparable levels showing hypermnesia. However, across tests, correct classification of both item types decreased at comparable levels. Collectively, hypermnesia as measured by net recall is possible for items from multiple sets, but at the cost of accurate source information.     

Classification accuracy across multiple tests following item method directed forgetting

We investigated recall of line-drawing pictures paired at study with an instruction either to remember (TBR items) or to forget (TBF items). Across three 7-minute tests, net recall (items reported independent of accuracy in instructional designation) and correctly classified recall (recall conditional on correct instructional designation) showed directed forgetting. That is, for both measures, recall of TBR items always exceeded recall of TBF items. Net recall for both item types increased across tests at comparable levels showing hypermnesia. However, across tests, correct classification of both item types decreased at comparable levels. Collectively, hypermnesia as measured by net recall is possible for items from multiple sets, but at the cost of accurate source information.     

Hypermnesia and total retrieval time

Recall performance sometimes improves over repeated recall attempts, a phenomenon dubbed hypermnesia. A critical theoretical issue is whether hypermnesia is due to repeated testing per se or increased retrieval time. The present experiments investigated by contrasting five testing conditions. All participants were presented with the same study list followed by either two shorter recall tests or a single longer test. In the multiple test conditions, the tests were either separated by a (filled) 7-minute interval (the multiple-split condition), or presented consecutively, with no break (the multiple-immediate condition). In the single test conditions, the test either began at the start of the recall session, after a (filled) 7-minute delay, or with a 7-minute interruption inserted in the middle. The multiple-split condition produced more reminiscence and hypermnesia than the multiple-immediate condition. More importantly, the multiple-split condition produced greater cumulative recall than any of the other conditions (which did not differ among themselves). That is, single and repeated recall tests of equal total duration are not functionally equivalent.     

Hypermnesia and total retrieval time

Recall performance sometimes improves over repeated recall attempts, a phenomenon dubbed hypermnesia. A critical theoretical issue is whether hypermnesia is due to repeated testing per se or increased retrieval time. The present experiments investigated by contrasting five testing conditions. All participants were presented with the same study list followed by either two shorter recall tests or a single longer test. In the multiple test conditions, the tests were either separated by a (filled) 7-minute interval (the multiple-split condition), or presented consecutively, with no break (the multiple-immediate condition). In the single test conditions, the test either began at the start of the recall session, after a (filled) 7-minute delay, or with a 7-minute interruption inserted in the middle. The multiple-split condition produced more reminiscence and hypermnesia than the multiple-immediate condition. More importantly, the multiple-split condition produced greater cumulative recall than any of the other conditions (which did not differ among themselves). That is, single and repeated recall tests of equal total duration are not functionally equivalent.     

Degree of learning,interpolated tests,and rate of forgetting

The purpose of the two experiments reported here was to observe the effects of degree of learning, interpolated tests, and retention interval, primarily on the rate of forgetting of a list of words, and secondarily on hypermnesia for those words. In the first experiment, all the subjects had one study trial on a list of 20 common words, followed by two tests of recall. Half of the subjects had further study and test trials until they had learned the words to a criterion of three correct consecutive recalls. Two days later, half of the subjects under each learning condition returned for four retention tests, and 16 days later, all the subjects returned for four tests. Experiment 2 was similar, except that all the subjects had at least three study trials followed by four recall tests on Day 1, intermediate tests were given 2 or 7 days later, and they all had final tests 14 days later. The results showed that rate of forgetting was attenuated by an additional intermediate set of tests but not by criterion learning. Hypermnesia was generally found over the tests that were given after a retention interval of 2 or more days. The best predictor of the amount of hypermnesia over a set of tests was the difference between overall cumulative recall and net recall on the first test of the set.     

Reminiscence, forgetting, and hypermnesia using face-name learning: isolating the effects using recall and recognition memory measures

A face-name learning paradigm was used to study phenomena involved in reminiscence, forgetting, and hypermnesia. Individuals introduced themselves on videotape while participants tried to learn their names. The presence of cues during testing increased overall performance but decreased hypermnesia in Experiment 1. Significant recognition memory effects were found for reminiscence and hypermnesia in Experiments 2 and 3. Experiment 3 also showed no interference from activities between testing sessions, but did show facilitating effects from exposure to photographs of target faces and to exposure of target names. The results were interpreted as showing support for reminiscence effects being primarily caused by imagery redintegration and effects consistent with stimulus sampling theories.     

Reminiscence,forgetting, and hypermnesia using face–name learning: Isolating the effects using recall and recognition memory measures

A face–name learning paradigm was used to study phenomena involved in reminiscence, forgetting, and hypermnesia. Individuals introduced themselves on videotape while participants tried to learn their names. The presence of cues during testing increased overall performance but decreased hypermnesia in Experiment 1. Significant recognition memory effects were found for reminiscence and hypermnesia in Experiments 2 and 3. Experiment 3 also showed no interference from activities between testing sessions, but did show facilitating effects from exposure to photographs of target faces and to exposure of target names. The results were interpreted as showing support for reminiscence effects being primarily caused by imagery redintegration and effects consistent with stimulus sampling theories.     

The role of recall time in producing hypermnesia

In two experiments subjects presented with either words or pictures showed improved recall over three successive recall tests for both types of materials, partially replicating Erdelyi’s finding of hypermnesia. However, these subjects did not recall more unique items than other subjects who received only one test equated in time with the three shorter ones. It is concluded that hypermnesia results from simply allowing subjects additional recall time. In a third experiment subjects were shown to recall additional information even after a long recall period employed during an experimental session. This surprising amount of item recovery during long recall periods is attributed to the use of subjective retrieval cues that are thought to function in a manner analogous to externally manipulated cues.     

Source‐monitoring accuracy across repeated tests following directed forgetting

The repeated recall of items from lists that participants were earlier instructed to either remember or to forget was examined in two experiments. RR participants (those instructed to remember both lists they were presented) tended to recall more List 1 items than FR participants (those instructed to forget the first list and to remember the second list). FR participants recalled more List 2 items than did RR participants, but only when directed to report those items (Experiment 1), not when directed to report items from both lists (Experiment 2). Participants experienced difficulty correctly reporting the list source of items they recalled and incorrect source recall increased across tests, showing hypermnesia. This later result underscores the need for caution when assessing the accuracy of information retrieved from multiple sources across repeated tests. Together, the data patterns provide support for the retrieval dynamics account of hypermnesia, the context‐change account of directed forgetting, and limited support for the retrieval inhibition view of directed forgetting.     

Hypermnesia for high-imagery words: The effects of interpolated tasks

The purpose of this study was to determine whether hypermnesia (improved net recall over time) can be differentially affected by manipulating the nature of tasks performed during the intervals between successive recall trials. In Experiment 1, all subjects were asked to imaginally encode separate words and were tested three times for recall. The control group (no interpolated task) produced the hypermnesia effect. Both groups performing interpolated tasks showed significantly lower recall. A second experiment was conducted in order to replicate these results and to examine the effects of intertest rehearsal on hypermnesia. In Experiment 2, subjects were asked to encode pairs of words using interactive-imagery instructions. Six different interpolated task conditions were employed, varying in the degree to which subsystems of working memory were used. Groups performing imaginal interpolated tasks showed no hypermnesia, whereas those performing nonimaginal tasks did. These findings suggest that access to working memory (see Baddeley, 1986) is not necessary for hypermnesia.     

Selective disruption of hypermnesia for pictures and words

In this study, we investigated the effects of various interpolated tasks on hypermnesia (improved recall across repeated tests) for pictures and words. In five experiments, subjects studied either pictures or words and then completed two free-recall tests, with varying activities interpolated between the tests. The tasks performed between tests were varied to test several hypotheses concerning the possible factor(s) responsible for disruption of the hypermnesic effect. In each experiment, hypermnesia was obtained in a control condition in which there was no interpolated task between tests. The remaining conditions showed that the effect of the interpolated tasks was related to the overlap of the cognitive processes involved in encoding the target items and performing the interpolated tasks. When pictures were used as the target items, no hypermnesia was obtained when subjects engaged in imaginal processing interpolated tasks, even when these tasks involved materials that were very distinct from the target items. When words were used as the target items, no hypermnesia was obtained when the interpolated tasks required verbal/linguistic processing, even when the items used in these tasks were auditorily presented. The results are discussed in terms of a strength-based model of associative memory.     

The self-choice effect from a multiple-cue perspective

The self-choice effect refers to the fact that self-chosen items are remembered better than experimenter-assigned items (Takahashi, 1991). The present study investigated the hypothesis that (a) response choice involves relational processing as activation of both target and context items, and (b) such activated context items are effective as potential retrieval cues for recall of target items. In the experiment, participants chose (choice condition) or were assigned (force condition) a target to remember for each trial. Prior to free recall of the target items, context words, related new words, or unrelated words were presented in a recognition task as potential retrieval cues. The results of a subsequent free recall test indicated that the incidental cues were more effective in the choice condition than in the force condition. Also, recognition resulted in a greater rate of successfully recognized context words at the cost of increasing falsely recognized related new words in the choice condition in comparison with the force condition. These results indicated that response choice activates context items at encoding, which operate as potential retrieval cues for recall of target items. Such cuing mechanisms operative in the self-choice effect are consistent with the multiple-cue theory proposed by Soraci et al. (1994; see also Soraci et al., 1999) for generative processing.     

High-priority event instructions affect implicit and explicit memory tests

Previous work has shown that instructing subjects to give special priority to one target event in a list enhances recall for that event, but impairs recall for the events immediately preceding it (Tulving, 1969). We examined the benefit of high-priority instructions, and the retrograde amnesia for previous items, in three experiments that included two explicit tests of memory (free recall and cued recall with word-stem cues) and an implicit test (word-stem completion). Experiments 1 and 2 revealed a beneficial effect of high-priority instructions on memory for the target events in both free recall and primed word-stem completion. Retrograde amnesia for previous events was either absent (Experiment 1) or modest (Experiment 2) in free recall; however, no evidence for amnesia occurred on the implicit test. In Experiment 3, we asked if the benefit of high-priority instructions on the implicit test was due to contamination from intentional recollection, by employing the logic of the retrieval-intentionality criterion via a levels-of-processing manipulation. The results showed a beneficial effect of high-priority instructions on free recall, word-stem cued recall, and word-stem completion. Level of processing affected the two explicit tests, but not the implicit test, indicating that it induced incidental retrieval. We conclude that the benefit of high-priority instructions occurred on all three tests used in these experiments. In contrast, the phenomenon of retrograde amnesia occurred in free recall, but not in primed word-stem completion.     

Total retrieval time and hypermnesia: Investigating the benefits of multiple recall tests

Hypermnesia is an increase in recall over repeated tests. A core issue is the role of repeated testing, per se, versus total retrieval time. Prior research implies an equivalence between multiple recall tests and a single test of equal total duration, but theoretical analyses indicate otherwise. Three experiments investigated this issue using various study materials (unrelated word lists, related word lists, and a short story). In the first experimental session, the study phase was followed by a series of short recall tests or by a single, long test of equal total duration. Two days later, participants took a final recall test. The multiple and single test conditions produced equivalent performance in the first session, but the multiple test group exhibited less forgetting and fewer item losses in the final test. In a fourth experiment, using a brief delay (15 min) between the recall sessions, the multiple recall condition produced greater hypermnesia as well as fewer item losses. In addition, final recall was significantly higher in the multiple than in the single test condition in three of the four experiments. Thus, single and repeated recall tests of equal total duration are not functionally equivalent, but rather produce differences observable in subsequent recall tests.     

Reminiscence and hypermnesia in children's eyewitness memory

Three experiments examined reminiscence and hypermnesia in 5- and 6-year-olds' memory for an event across repeated interviews that occurred either immediately afterward (Experiment 1) or after a 6-month delay (Experiments 2 and 3). Reminiscence (recall of new information) was reliably obtained in all of the experiments, although the numbers of new items recalled were fewer after a delay than when the interviews occurred immediately afterward. Hypermnesia (increasing total recall over repeated recall attempts) was obtained only in Experiment 1 when interviews occurred immediately and 24 h after the event.     

Note on subjects' hypotheses in multiple-cue probability learning

Subjects' hypotheses in multiple-cue probability learning was studied by trial-by-trial verbal reports in tasks with linear and nonlinear cue-criterion relations. In accordance with earlier findings, the results of the present experiment show that subjects learned linear tasks rapidly, while nonlinear tasks were not learned at all. The subjects' verbal hypotheses show that the subjects were concerned with rules for combining cue values, rather than with cue-criterion functions. This explains why the subjects fail to learn nonlinear multiple-cue tasks. It also shows that, although the subjects seem to learn multiple-cue tasks through a hypothesis testing process of the same kind as in single-cue probability tasks, the hypotheses tested in multiple-cue tasks are different from those tested in single-cue tasks. Finally, the present results suggest that the picture of the subjects' cognitive models of multiple-cue probability learning tasks provided by the customary multiple regression analysis may be fundamentally misleading in that it suggests that the subjects learn the validity of each cue rather than a combination rule.     

Part‐set cuing of texts,scenes, and matrices

In four experiments, we extended the study of part‐set cuing to expository texts and pictorial scenes. In Experiment 1, recall of expository text was tested with and without part‐set cues in the same order as the original text; cues strongly impaired recall. Experiment 2 repeated Experiment 1 but used cues in random order and found significant but reduced impairment with cuing. Experiments 3 and 4 examined the part‐set cuing of objects presented in a scene or matrix and found virtually no effect of cuing. More objects were recalled from the scene than from the matrix, indicating that the scene's organization aided memory, but the cues did not assist recall. These results extend the domains in which part‐set cues have either impaired or failed to improve recall. Implications for education and eyewitness accounts are briefly considered.