The role of exemplar typicality and encoding strategies in category retrieval-induced forgetting

Selective retrieval practice of category exemplars often impairs the recall of related items, a phenomenon known as retrieval-induced forgetting (RIF). In Experiment 1 the role of item typicality (high, low) and presentation format of category exemplars (random, grouped) were analysed, while in Experiment 2 two encoding strategies (inter and intracategory) to modulate RIF were tested. Exemplar typicality was the critical factor underlying RIF. Competition during retrieval practice rendered RIF in the typical exemplars, but RIF did not appear when the exemplars were low typicality. The greater impairment of strong exemplars is in line with the inhibitory account of RIF and the notion of interference dependence. Inhibition appeared with random and grouped presentations suggesting that presentation format of the exemplars is not a critical factor in modulating RIF in a category-cued recall task. Distinctive processing instructions using sentences that connected items from different categories (intercategory strategy) and integration instructions by using size to organise the exemplars within categories (intracategory strategy) easily avoided competition and the need of inhibition processes in recall.     

How focus at encoding affects children’s source monitoring

Retention of source information is enhanced by focus on speakers’ feelings about statements even though recognition is reduced for both adults and children. However, does any focus on another person lead to enhanced source monitoring, or is a particular kind of focus required? Does other-focus enhance source monitoring, or does self-focus detract from it? In Experiment 1, 4- and 6-year-olds watched two speakers make statements in a no-focus control or with focus directed on how they (or a speaker) felt about the statements or on perceptual features about themselves (or the speaker). Source monitoring decisions were enhanced by other-focus in both the perceptual and emotional conditions. However, the effect was larger for the emotional condition, and source monitoring exceeded no-focus controls only for this condition. Experiment 2 showed no effect of other-focus versus self-focus on source monitoring when questions were semantic.     

The effect of age on rule-based category learning

An explicit, rule-based, category-learning task with abstract visual stimuli was administered to 50 healthy older adults and 48 younger adults. Accuracy and reaction time (RT) were examined for the effects of age, perceptual abilities, rule memory, rule complexity, stimulus novelty, and response competition. Older adults performed at equivalent levels to younger adults when applying a simple rule, but showed performance decrements when applying a more complex rule. The age effect interacted with both stimulus novelty and response competition, and was not eliminated after controlling for basic perceptual abilities and rule memory. The authors suggest that older adults show category learning deficits in conditions that require enhanced cognitive control. These results are discussed in reference to the growing body of literature regarding age-related change in executive abilities and frontal lobe function.     

The effect of increasing the memorability of category instances on estimates of category size

According to Tversky and Kahneman’s (1973) availability heuristic, people sometimes make use of the ease with which instances are retrieved when they have to estimate proportions or frequencies. One implication of this availability heuristic is that any factor that affects memorability of instances from a category should also affect the estimated category size. In one of their experiments, Tversky and Kahneman found that, after being presented with a list of names, people judged the more famous names to be more frequent. Similarly, recall was found to be greater for the more famous names. Three experiments that used Tversky and Kahneman’s paradigm are reported. Repeating nonfamous names resulted in their increased recallability and a corresponding increase in estimates of their frequency (Experiments 1 and 3). Making nonfamous names more salient (Experiment 3) also had parallel effects on recallability and frequency estimates, indicating that different memory manipulations affected availability in a similar fashion. Furthermore, reliance on the heuristic was not changed as a function of prior knowledge (Experiment 2) or practice (Experiment 3)     

认知灵活性对概率类别学习的影响

本研究采用“数字-字母转换任务”区分高低认知灵活性者, 构建概率配对模式相同但形式不同的两个概率类别学习任务, 借助ERP技术探讨认知灵活性对概率类别学习任务的作用特点与机制。结果发现, 本研究的两个任务中, 高认知灵活性组的规则习得水平均优于低认知灵活性组, 认知灵活性能促进概率类别的学习。同时, 对不同学习阶段的ERPs分析结果显示, 高认知灵活性者在概率类别学习中的优势源于反馈加工过程。     

Recall-to-reject: The effect of category cues on false recognition

Four experiments examined the effect of category cueing on recall-to-reject, one of the central memory-editing mechanisms thought to prevent the occurrence of false memories. When category names were used as retrieval cues, the typically observed false recognition effect was eliminated for semantically associated distractors (Experiment 1a) and, moreover, a reduction in the absolute level of the false alarm rate was found for phonologically associated distractors (Experiment 2a). In addition to the old/new-recognition data, analyses using multinomial models support the interpretation that category cueing was successful in increasing the probability of recall-to-reject (Experiments 1b and 2b). The results are in line with dual-process theories of recognition memory and provide further evidence for recall-to-reject in single item recognition. They demonstrate its potential to reduce false recognition even when explicit instructions are not given. In addition, the results demonstrate that the paradigm can give rise to side effects that oppose recall-to-reject. A simultaneous familiarity increase can explain why many studies failed to find evidence for recall-to-reject in terms of false alarm rates.     

Recall-to-reject: The effect of category cues on false recognition

Four experiments examined the effect of category cueing on recall-to-reject, one of the central memory-editing mechanisms thought to prevent the occurrence of false memories. When category names were used as retrieval cues, the typically observed false recognition effect was eliminated for semantically associated distractors (Experiment 1a) and, moreover, a reduction in the absolute level of the false alarm rate was found for phonologically associated distractors (Experiment 2a). In addition to the old/new-recognition data, analyses using multinomial models support the interpretation that category cueing was successful in increasing the probability of recall-to-reject (Experiments 1b and 2b). The results are in line with dual-process theories of recognition memory and provide further evidence for recall-to-reject in single item recognition. They demonstrate its potential to reduce false recognition even when explicit instructions are not given. In addition, the results demonstrate that the paradigm can give rise to side effects that oppose recall-to-reject. A simultaneous familiarity increase can explain why many studies failed to find evidence for recall-to-reject in terms of false alarm rates.     

The effect of category learning on sensitivity to within-category correlations

A salient property of many categories is that they are not just sets of independent features but consist of clusters of correlated features. Although there is much evidence that people are sensitive to between-categories correlations, the evidence about within-category correlations is mixed. Two experiments tested whether the disparities might be due to different learning and test tasks. Subjects learned about categories either by classifying items or by inferring missing features of items. Their knowledge of the correlations was measured with classification, prediction, typicality, and production tests. The inference learners, but not the classification learners, showed sensitivity to the correlations, although different tests were differentially sensitive. These results reconcile some earlier disparities and provide a more complete understanding of people's sensitivities to within-category correlations.     

The effect of attentional focus on social anxiety

The aim of the present study was to examine the effect of attentional focus on social anxiety in a group of high and low blushing-anxious subjects. One hundred and fourteen psychology undergraduate students were screened using the Fear of Blushing subscale of the Blushing Questionnaire [B?gels, S. M., & Reith, W. (1999). Validity of two questionnaires to assess social fears: The Dutch social phobia and anxiety questionnaire and the blushing, trembling and sweating questionnaire. Journal of Psychopathology and Behavioral Assessment, 21, 51-66]. Those with the most extreme scores in the top and bottom 20% of the distribution were selected to form a high (n=22) and a low (n=22) blushing-anxious group. Subjects were randomly allocated to either a self-focused attention (SFA) condition or a task-focused attention (TFA) condition. They were asked to engage in a 5 min conversation with the first author, and were instructed to either self-focus (SFA condition) or task-focus (TFA condition). Levels of social anxiety and self-awareness were measured using visual analogue scales. Results suggest that the there was a significant condition by group interaction, with high blushing individuals showing considerably higher levels of social anxiety in the SFA condition compared to the TFA condition while low blushing individuals showed no significant difference across the two conditions.     

Typhoid Pollyanna: The effect of category valence on retrieval order of positive and negative category members

Previous research suggests that people process pleasant information more efficiently than unpleasant information. This phenomenon has been illustrated in a variety of contexts and paradigms, and is frequently referred to as the Pollyanna principle. One important aspect of the Pollyanna principle is that people tend to retrieve pleasant members of a category from semantic memory prior to unpleasant members of the same category. However, we propose that the retrieval advantage of favourably viewed category members holds only for positive categories and that prototypicality of category members might be a better predictor of ease of retrieval than favourability. These possibilities were tested in two studies. In Study 1, favourability effects on retrieval order were observed for positive categories but not for neutral or negative categories. In Study 2, prototypical category members were retrieved before less prototypical category members for both positive and negative categories. These results suggest that the Pollyanna principle might be the result of a confound between favourability and prototypicality for members of favourable categories.     

The effects of implementation intention strategies on prospective memory cue encoding

Implementation intentions, which include a structured verbal statement and mental imagery, improve prospective memory performance (i.e. remembering to execute delayed intentions). To investigate whether, and how, implementation intention strategies affect encoding processes we had participants complete a thought probe procedure immediately after forming the intention to remember to press Q when seeing fruit words. In Experiment 1, an implementation intention verbal statement (relative to control statement) significantly increased generation of high typicality exemplars (apple, banana, orange). In Experiment 2, an implementation intention imagery procedure (relative to control imagery) produced similar outcomes. In Experiment 3, combining the statement and imagery components of the implementation intention (relative to control statement and imagery) demonstrated even more potent effects (e.g. three-fold increase in fruit exemplars generated). In Experiment 4, we tested whether the control statement versus control imagery procedure differentially affected encoding, but these control procedures showed no significant differences. An interesting, unanticipated finding was that there was significantly less mind wandering in the implementation intention conditions relative to the control conditions. The current experiments provide novel information on the processes operating during intention encoding, and support the classic view that implementation intentions increase the encoding of specific retrieval cues.     

Sex-contingent face aftereffects depend on perceptual category rather than structural encoding

Many studies have used visual adaptation to investigate how recent experience with faces influences perception. While faces similar to those seen during adaptation phases are typically perceived as more 'normal' after adaptation, it is possible to induce aftereffects in one direction for one category (e.g. female) and simultaneously induce aftereffects in the opposite direction for another category (e.g. male). Such aftereffects could reflect 'category-contingent' adaptation of neurons selective for perceptual category (e.g. male or female) or 'structure-contingent' adaptation of lower-level neurons coding the physical characteristics of different face patterns. We compared these explanations by testing for simultaneous opposite after effects following adaptation to (a) two groups of faces from distinct sex categories (male and female) or (b) two groups of faces from the same sex category (female and hyper-female) where the structural differences between the female and hyper-female groups were mathematically identical to those between male and female groups. We were able to induce opposite aftereffects following adaptation between sex categories but not after adaptation within a sex category. These findings indicate the involvement of neurons coding perceptual category in sex-contingent face aftereffects and cannot be explained by neurons coding only the physical aspects of face patterns.     

The effect of category variability in perceptual categorization

Exemplar and distributional accounts of categorization make differing predictions for the classification of a critical exemplar precisely halfway between the nearest exemplars of 2 categories differing in variability. Under standard conditions of sequential presentation, the critical exemplar was classified into the most similar, least variable category, consistent with an exemplar account. However, if the difference in variability is made more salient, then the same exemplar is classified into the more variable, most likely category, consistent with a distributional account. This suggests that participants may be strategic in their use of either strategy. However, when the relative variability of 2 categories was manipulated, participants showed changes in the classification of intermediate exemplars that neither approach could account for.     

The effect of midazolam on implicit and explicit memory in category exemplar production and category cued recall

Transfer-appropriate processing theory (Roediger, Weldon, & Challis, 1989) proposes that dissociations between performance on explicit and implicit memory tests arise because these tests often rely on different types of information processing (e.g., perceptual processing vs conceptual processing). This perspective predicts that implicit and explicit memory tasks that rely primarily on conceptual processing should show comparable results, not dissociations. Numerous studies have demonstrated such similarities. It is, however, possible that these results arise from explicit memory contamination of performance on implicit memory tasks. To address this issue, an experiment was conducted in which participants were administered the sedative midazolam prior to study. Midazolam is known to create a temporary, but dense, period of anterograde amnesia. The effects of blocking stimulus materials by semantic category at study and generation at study were investigated on category exemplar production and category-cued recall. The results of this study demonstrated a dissociation of the effects of midazolam on category exemplar production and category-cued recall. Specifically, midazolam reduced the effect of blocking stimulus materials in category-cued recall, but not in category exemplar production. The differential effect of midazolam on explicit and implicit memory is at odds with transfer-appropriate processing theory and suggests that theories of memory must distinguish the roles of different types of conceptual processing on implicit and explicit memory tests.     

The effect of midazolam on implicit and explicit memory in category exemplar production and category cued recall

Transfer‐appropriate processing theory (Roediger, Weldon, & Challis, 1989) proposes that dissociations between performance on explicit and implicit memory tests arise because these tests often rely on different types of information processing (e.g., perceptual processing vs conceptual processing). This perspective predicts that implicit and explicit memory tasks that rely primarily on conceptual processing should show comparable results, not dissociations. Numerous studies have demonstrated such similarities. It is, however, possible that these results arise from explicit memory contamination of performance on implicit memory tasks. To address this issue, an experiment was conducted in which participants were administered the sedative midazolam prior to study. Midazolam is known to create a temporary, but dense, period of anterograde amnesia. The effects of blocking stimulus materials by semantic category at study and generation at study were investigated on category exemplar production and category‐cued recall. The results of this study demonstrated a dissociation of the effects of midazolam on category exemplar production and category‐cued recall. Specifically, midazolam reduced the effect of blocking stimulus materials in category‐cued recall, but not in category exemplar production. The differential effect of midazolam on explicit and implicit memory is at odds with transfer‐appropriate processing theory and suggests that theories of memory must distinguish the roles of different types of conceptual processing on implicit and explicit memory tests.     

The subjective estimation of relative syllable frequency

Ss are able to judge the relative frequency of occurrence in English of nonmorphemic syllables independent of phoneme frequency. The results support a theory of speech perception based on the syllable as a unit as opposed to the phoneme.     

The effect of encoding training on perceptual recall

The effect of encoding training on tachistoscopic performance was measured by training groups of Ss in either an octal or a standardized English encoding of nine place binary numbers. A control group of Ss was allowed to encode ad lib during an equivalent training period. Performance was measured before, during and after the encoding training. It was found that imposing a code on S impaired tachistoscopic performance both during and for some time after the encoding training. Possible reasons for this effect are discussed.     

Phonemic and category encoding of unattended words in dichotic listening

The claim that unattended items in dichotic listening are categorized (Smith & Groen, 1974) was examined in three experiments using dichotic presentation and probe reaction time. Negative probe words from the unattended list were more difficult to reject when the dichotic lists shared a semantic category than when they differed in category, whether or not the attended list was precued, thereby replicating and extending Smith and Groen’s findings. The difficulty with intralist probes following dichotic lists of a homogeneous category was found to be a special case of the probe similarity effect, since extralist probes of the same category as the attended input were rejected more slowly (and with more errors) than different category probes. The effects of category homogeneity were evident on the attended, but not on the unattended, inputs (Experiment 2). The third experiment compared focused and divided attention with dichotic lists of unrelated items. Phonemically similar probes were more difficult to reject when related to items on the attended channel in the focused condition than either channel in divided attention, and easiest to reject when similar to an unattended item. Linear regression confirmed that the unattended input was processed only at a precategorical (acoustic) level.     

The effect of structure on scanning strategies

Ss heard four-digit strings and saw a two-digit probe immediately after each. Every possible combination of two digits taken from the string, as well as each member of the string combined with some digit from the negative set was tested. Reaction times for verifying that both probe digits occurred in the string reveal that Ss grouped the members of the string into two ordered pairs. This result argues that the structure Ss might assign to so-called random strings must be considered when discussing scanning strategies. Structural explanations of two common patterns of reaction times are presented.     

The effect of uncertainty on the detection of frequency modulation at low modulation rates

Frequency modulation detection performance is compared in two conditions of stimulus variability. The data show that when the modulation rate is randomized within an experimental block, performance is somewhat poorer than when the modulation rate is fixed. The results are interpreted within the framework of a template matching model for modulation detection. They suggest that a template is acquired in part from experimental context and in part from a multistage template matching process.