Distraction,amnesia, and the next-in-line effect

Two studies use a free recall task to track, moment by moment, cognitive repercussions of an upcoming performance. As in earlier research, subjects display impaired recall for events which immediately precede an anticipated public performance. This “next-in-line effect” occurs even if the “performance” consists of reading a word to oneself. However, subjects show no memory deficit if their performance is not anticipated, and they have generally poor recall if they know they will be performing—but not when. Distraction and amnesia accounts of these recall deficits are discussed. Ancillary findings illuminate the organization of memory in social settings.     

“P300” and memory: Individual differences in the von Restorff effect

Event-related brain potentials (ERPs) were elicited by words in a free recall paradigm that included a novel item. The P300 component of the ERP is elicited by novel, task-relevant events, and we tested the hypothesis that P300 is a manifestation of the cognitive processing invoked during “context updating.” If the degree to which current representations in working memory need revision is related to P300 amplitude, then the P300 elicited by a given item should be related to the ability to recall that item on a subsequent test. Forty lists were presented to 12 subjects in each of two sessions. The lists were 15 words long, and 1 word, in position 6 through 10, was “isolated” by changing its size. Most subjects recalled these isolated words more often than other words in the same positions (von Restorff effect), and these words also elicited larger P300s than other words. Analysis of variance on the component scores from a principal components analysis revealed that words recalled had a larger amplitude P300 (on initial presentation) than words not recalled. Striking individual differences emerged, and there were strong relationships between the von Restorff effect, overall recall performance, mnemonic strategies, and the association between components of the ERP and recall performance. The overall recall performance of subjects who reported simple (rote) mnemonic strategies was low, but they showed a high von Restorff effect. For these subjects the amplitude of the P300 elicited by words during initial presentation predicted later recall. In contrast, subjects who reported complex mnemonic strategies remembered a high percentage of words and did not show a von Restorff effect. For these subjects P300 did not predict later recall, although a later “slow wave” component of the ERP did. The initial response to isolated items was the same for all subjects (a large P300), and all subjects recognized the isolates faster than other words in a recognition test given at the end of each session. The subjects in whom P300 did not predict recall reported mnemonic strategies that involved organizing the material. These strategies continue long after the time period reflected by P300 (600 msec). Because they were so effective they may have overshadowed the relationship between P300 and recall, which is based on the initial encoding of an event. Our interpretations were further confirmed and clarified from data obtained in a final grand recall and in the recognition test.     

Mood-congruent free recall bias in anxious individuals is not a consequence of response bias

The status of mood-congruent free recall bias in anxious individuals was evaluated following incidental encoding of target words. Individuals with high and low levels of trait anxiety completed a modified Stroop task, which revealed an attentional bias for threat-related stimuli in anxious individuals. This group was significantly slower in naming the colour in which threat-related words were displayed compared to neutral words. In a subsequent free recall test for the words used in the modified Stroop task, anxious individuals recalled more threat-related words compared to low-anxious people. This difference was significant even when controlling for the false recall of items that had not been presented during study. These results support the view put forward by Russo, Fox, Bellinger, and Nguyen-Van-Tam (2001) that mood-congruent free recall bias in anxious individuals can be observed if the target material is encoded at a relatively shallow level. Moreover, contrary to Dowens and Calvo (2003), the current results show that the memory advantage for threat-related information in anxious individuals is not a consequence of response bias.     

Mood-congruent free recall bias in anxious individuals is not a consequence of response bias

The status of mood-congruent free recall bias in anxious individuals was evaluated following incidental encoding of target words. Individuals with high and low levels of trait anxiety completed a modified Stroop task, which revealed an attentional bias for threat-related stimuli in anxious individuals. This group was significantly slower in naming the colour in which threat-related words were displayed compared to neutral words. In a subsequent free recall test for the words used in the modified Stroop task, anxious individuals recalled more threat-related words compared to low-anxious people. This difference was significant even when controlling for the false recall of items that had not been presented during study. These results support the view put forward by Russo, Fox, Bellinger, and Nguyen-Van-Tam (2001) that mood-congruent free recall bias in anxious individuals can be observed if the target material is encoded at a relatively shallow level. Moreover, contrary to Dowens and Calvo (2003), the current results show that the memory advantage for threat-related information in anxious individuals is not a consequence of response bias.     

Recall versus recognition: a methodological note

Some current investigators have made direct comparisons of recognition performance with cued recall. In other instances, indirect comparisons of recognition and recall have been made by observing the difference in recognition performance with different types of target material, for example, high- and low-frequency words; this difference has been then compared with the difference obtained when recall is used to measure retention of the same type of target materials. Finally, some experimenters have examined how recognition performance is related to the type of target material that is used, for example, words, pictures, and so on. The results obtained from all of these studies have been used to make inferences about the nature of the memorial process. We have attempted to call attention to the generally accepted but neglected finding that performance on any recognition test can be manipulated by changing the characteristics of the distractors, thus casting doubt on the generality of the experimental findings as well as their theoretical implications.     

Good and bad effects of phonological similarity on word and nonword recall: The role of beginnings and ends

This study explored whether earlier results of differential (harmful vs. helpful) short-term memory effects of shared syllables at nonword beginnings compared to ends could be replicated for lists of bisyllabic real words. We studied immediate serial recall of lists that had phonologically redundant syllables at the beginnings or ends of two-syllable words or nonwords. The results showed that redundancy at the beginning had a negative effect on both types of material. Redundancy at the end did not impair memory for nonwords but harmed the serial recall of words. Irrespective of lexicality, lists of beginning-redundant items were more difficult to recall than end-redundant items. The distribution of errors suggested that the better recall of end-redundant lists compared to beginning-redundant lists was related to a positive effect at encoding and/or retention, independent of effects at recall, for both words and nonwords.     

Why does self-reference promote incidental encoding?

Answering a question regarding a stimulus word can cause incidental encoding of the word itself. The thoroughness of the encoding depends in part upon what question is answered. For example, saying whether a word describes oneself causes a particularly high degree of incidental encoding. The study reported here investigated several variables that have been proposed as mediators of that effect. As in previous research, subjects completed an incidental-encoding and recall procedure. They then rated (a) the quality and degree of affect that they would experience if each stimulus word were to be applied to them, (b) the importance to them of the behavioral/psychological dimension implied by the stimulus word, and (c) the degree to which they saw themselves as distinctive on that dimension. As in previous studies, deciding whether a word described the self increased the likelihood of subsequent recall. There also was a highly significant interaction such that words judged to be applicable to self were recalled better than those judged not to be applicable. There was no evidence, however, of a mediational role for any other variable studied. Discussion centers on theoretical implications of the data.     

Cue utilization following different forms of encoding in mildly, moderately, and severely demented patients with Alzheimer's disease

The ability of patients with Alzheimer's disease (AD) to utilize semantic category cues in order to improve memory performance was examined. Categorizable lists of words or objects were presented under five different encoding conditions: (a) nouns, (b) objects, (c) objects with a semantic orienting question, (d) objects with self-generated motoric acts, and (e) objects with experimenter-instructed motoric acts. Subjects were asked to memorize the items for a free recall test, and were subsequently provided with the category names in a cued recall test. Mildly, moderately, and severely demented AD patients, and a group of normal older adults participated in the study. Results showed that normal older adults and mildly demented AD subjects were able to utilize cues to improve memory performance in all conditions. Moderately demented patients utilized cues in all conditions except in the verbal condition (condition [a]), whereas severely demented patients utilized cues only in the motoric condition (condition [e]). These results suggest that the ability to utilize category cues following a motoric encoding is preserved later in AD than the ability to utilize cues after a semantic encoding.     

Characteristics of spatial memory span: Is there an analogy to the word length effect, based on movement time?

In studies of verbal short-term memory it has been shown that the length of words to be remembered affects the size of memory span. This word-length effect is attributed to relationships between the rate of rehearsal of verbal material and the time it takes to speak the words being rehearsed. For spatial memory span there may also be an internal rehearsal system linked to overt responding, and if there is a strong analogy to be drawn between the verbal and spatial domains then movement time between spatial targets should predict the number of spatial locations that can be recalled. In the experiments reported here the time taken to move between spatial targets is varied by altering the size of targets and the distance between them. No difference between span performance on a nine-block spatial span task were found, either on immediate recall or on recall after an interval. When recall is of items from an array of 27, grouped in nine sets of three, with only one location in any set being presented on any trial, there is an effect of display size. This effect is consonant with the argument that movement time is related to spatial rehearsal, but other explanations are also possible. However, if recall in this task is scored over the nine sets rather than over the 27 items, then there is no difference between the displays. The results indicate that performance on the normal nine-block spatial-span task cannot be predicted by movement time.     

Repetition and trace interaction: Superadditivity

This paper reports five experiments that examined memory for repeated and unrepeated pairs of words. In over 40 experimental comparisons, cued recall of the repeated pairs was better than it would have been if the words had been repeated as independent cognitive events. Therefore, memory traces do interact with other traces of the same nominal items. Our account of superadditive recall is that some encodings fail on the final test because they lack a needed piece of information. Specifically, some need additional item-specific information to enable access by the cue, and some need relational information for recall of the target. The second trial is an implicit test of memory, whose results give the system a heuristic basis for standing pat or doing more encoding. If a retrieved encoding needs less than a new one to become a success, it has a good chance of becoming a success, and recall is superadditive. However, if the ease of retrieving the encoding is for the wrong reasons, such as massed repetition, the item remains a failure, and recall is subadditive.     

Negative Cueing Effects with Weak and Strong Intralist Cues

In three experiments, we studied cueing effects of relational and itemspecific information after enacted and non-enacted encoding of short sentences (e.g. lift the pen, fold the paper). In Experiment 1, all subjects were instructed at encoding to remember only the nouns of these sentences; half of the subjects were informed about the categorical nature of the nouns, whereas the other half were not. At retrieval, all subjects were given a free recall test and a cued recall test with the verb of each sentence as the cue. In Experiment 2, all subjects were instructed at encoding to remember the whole sentence; as in Experiment 1, half of the subjects were informed about the categorical nature of the nouns and half were not. At test, all subjects were given two cued recall tests, one categorical cue for each noun in the first test and one verb cue and one categorical cue for each noun in the second test. In Experiment 3, at encoding, all subjects were informed about the categorical nature of nouns and were instructed to remember the whole sentence. In this experiment, the actions were performed with imaginary objects; free recall and cued recall tests were given to different subjects. In all three experiments, there was a negative effect of intralist cueing with verbs. This finding is at odds with the Encoding Specificity Principle, which assumes facilitation of cueing at retrieval if the cues were encoded together with the to-be-remembered information at encoding. Also, the effect of intralist cueing was different after encoding with enactment than after encoding without enactment; this difference holds true for enactment with real objects but not for enactment with imaginary objects. Enactment increased both the relational and the item-specific cueing efficiency. The results are discussed in terms of encoding interference between cues and targets and between item-specific processing and relational processing. Enacted encoding is conceived as integrating episodic information both with respect to item specificity and relational aspects of the information.     

Repetition,cuing, and state-dependent memory

Two experiments examined the effects of several types of repetition on state-dependent memory for conceptually categorized words. In both experiments, compatibility between pharmacological states at encoding and at retrieval facilitated the uncued recall of nonrepeated categories but had no appreciable effect on the recall of words within recalled categories. In both experiments, compatibility between encoding/retrieval states failed to facilitate the uncued recall of repeated categories li.e., categories whose names and/or exemplars were presented at least twice, in a constant or variable order, and with substantial spacing between successive presentations). And again, in both experiments, the level of uncued recall was higher for repeated than for nonrepeated categories, irrespective of the compatibility or incompatibility of encoding/retrieval states. These findings, together with other relevant observations reported in the literature, suggest that repetition in general, and repetition of category names in particular, influences recall in much the same ways as does explicit cuing with category names: It enhances the accessibility of higher order units, as reflected in uncued category recall, and it diminishes to the extent to which access to these units is state dependent.     

Presentation format effects in working memory: The role of attention

Four experiments are reported in which participants attempted to remember three or six concrete nouns, presented as pictures, spoken words, or printed words, while also verifying the accuracy of sentences. Hypotheses meant to explain the higher recall of pictures and spoken words over printed words were tested. Increasing the difficulty and changing the type of processing task from arithmetic to a visual/spatial reasoning task did not influence recall. An examination of long-term modality effects showed that those effects were not sufficient to explain the superior performance with spoken words and pictures. Only when we manipulated the allocation of attention to the items in the storage task by requiring the participants to articulate the items and by presenting the stimulus items under a degraded condition were we able to reduce or remove the effect of presentation format. The findings suggest that the better recall of pictures and spoken words over printed words result from the fact that under normal presentation conditions, printed words receive less processing attention than pictures and spoken words do.     

The interval for interference in conscious visual imagery

Three experiments are described that use dynamic visual noise (DVN) to interfere with words processed under visual and verbal processing instructions. In Experiment 1 DVN is presented to coincide with the encoding of the words or to coincide with the interval between encoding and recall. The results show that while DVN is a robust disruptor when it is applied during encoding to words processed under visual instruction, it has no effect during encoding when the words are processed under rote instruction. Moreover, DVN has no effect when it is applied during the retention interval, no matter what means are employed to encode the words. Experiment 2 extends these findings by again showing no effect of DVN during the retention interval, yet showing robust interference effects for visually processed words during recall. Finally, Experiment 3 demonstrates that the results of Experiments 1 and 2 cannot be explained by a difference in the time duration associated with application of DVN during the retention interval compared to during encoding and recall. Moreover, the differing decay functions for visually and verbally processed words during the intervals used in Experiment 3 suggest that any failure to cause interference is not because the two processing instructions resulted in words being retained in the same medium. The functions are consistent with word storage mechanisms reflecting appropriately verbal and visual properties. The results are discussed in terms of current models of visual working memory. It is argued that a full interpretation of the results requires a buffer mechanism as an important component of any model of visual working memory.     

The interval for interference in conscious visual imagery

Three experiments are described that use dynamic visual noise (DVN) to interfere with words processed under visual and verbal processing instructions. In Experiment 1 DVN is presented to coincide with the encoding of the words or to coincide with the interval between encoding and recall. The results show that while DVN is a robust disruptor when it is applied during encoding to words processed under visual instruction, it has no effect during encoding when the words are processed under rote instruction. Moreover, DVN has no effect when it is applied during the retention interval, no matter what means are employed to encode the words. Experiment 2 extends these findings by again showing no effect of DVN during the retention interval, yet showing robust interference effects for visually processed words during recall. Finally, Experiment 3 demonstrates that the results of Experiments 1 and 2 cannot be explained by a difference in the time duration associated with application of DVN during the retention interval compared to during encoding and recall. Moreover, the differing decay functions for visually and verbally processed words during the intervals used in Experiment 3 suggest that any failure to cause interference is not because the two processing instructions resulted in words being retained in the same medium. The functions are consistent with word storage mechanisms reflecting appropriately verbal and visual properties. The results are discussed in terms of current models of visual working memory. It is argued that a full interpretation of the results requires a buffer mechanism as an important component of any model of visual working memory.     

转换功能对汉语口吃者语音编码的影响

采用双任务范式比较了16名口吃者和16名非口吃者在数字转换任务的同时重复双声词和叠韵词的时间和口吃频率,考察转换功能对于汉语口吃者语音编码的影响。结果表明,转换功能影响汉语口吃者的语音编码：口吃者和非口吃者加工叠韵词比加工双声词需要更多的转换功能。研究结果支持口吃的“内在修正假说”,对口吃的诊断和治疗有重要启示。     

Memory, acquisition, and category clustering in learning-disabled children.

In Experiment 1, single trial, immediate-free recall of learning disabled and nondisabled children was compared. The primacy effect in learning-disabled children was lower, suggesting that rehearsal or other types of elaborative encoding may be deficient in these children. In Experiment 2, acquisition of randomly presented categorical lists in a multitrial-free recall task was compared in learning disabled and nondisabled children. One-half of each group was required to learn the same number of words (34 per list), whereas list length for the other half exceeded the primacy effect of each child in immediate-free recall to the same degree. When the same number of items was learned, acquisition was slower in learning disabled than nondisabled children. When the number of items varied according to the primacy effect of each child, acquisition of both groups was similar. Clustering was lower in learning disabled than nondisabled children. In Experiment 3, multitrial-free recall acquisition of categorical lists was examined in a subject-paced task. When the number of words learned exceeded the primacy effect of each child to the same degree, trials to criterion were similar in both groups but, when the children learned the same number of items, learning-disabled children required more trials to criterion. Presentation rates were faster in learning-disabled children. Presentation rates were negatively correlated with trials to criterion and positively correlated with clustering and primacy in immediate-free recall, suggesting that study time may be taken up by clustering, rehearsal, and/or other encoding strategies. Deficient elaborative encoding may be responsible for the slower acquisition of learning-disabled children.     

Adult Age Differences in Memory for Verbs and Nouns

Younger and older adults were asked to remember noun pairs (e.g., head – cap), verb pairs (e.g., bounce – throw), and verb-noun pairs (e.g., break – stick). For half of the pairs, participants used imagined objects and performed an action or series of related actions for each pair. For the other half of the pairs, participants read but did not perform the pairs. Free recall and cued recall tests revealed that age differences in memory for both performed and nonperformed items were larger for verbs than for nouns. The recall advantage of nouns over verbs was larger for older than for younger adults. Verbs are hypothesized to be more difficult for older adults to remember because they are more and less specific than nouns and because it is more difficult to integrate verbs with other words than to integrate nouns with other words.     

Remembering the good, forgetting the bad: intentional forgetting of emotional material in depression

The authors examined intentional forgetting of negative material in depression. Participants were instructed to not think about emotional nouns that they had learned to associate with a neutral cue word. The authors provided participants with multiple occasions to suppress the unwanted words. Overall, depressed participants successfully forgot negative words. Moreover, the authors obtained a clear practice effect. However, forgetting came at a cost: Compared with the nondepressed participants and with the depressed participants who were instructed to forget positive words, depressed participants who were instructed to forget negative words showed significantly worse recall of the baseline words. These results indicate that training depressed individuals in intentional forgetting could prove to be an effective strategy to counteract automatic ruminative tendencies and mood-congruent biases.     

Memory monitoring and memory performance: Linked closely or loosely?

Summary An experimental test of the metamemory hypothesis claiming a substantive positive relationship between memory monitoring and memory performance is provided. Forty-eight university students learned a set of abstract nouns. They were either instructed to make use of monitoring activities (experimental group), simply to learn the words (control-1) or to use non-metacognitive learning strategies (control-2). Prior to recall, the subjects had to predict the number of items they expected to remember. The experimental predictions were derived on two levels. First, prediction accuracy should be best for the experimental group. This is a necessary prerequisite for a valid test of the second prediction, namely that memory performance, too, should be best for the experimental group. Whereas the first prediction was confirmed, the second, vital for the metamemory hypothesis, was not. Thus, this hypothesis did not stand up to an experimental test, but would have been confirmed if tested by the correlation between prediction accuracy and memory performance.