Memory-basedsame-different conceptualization by pigeons

We first trained pigeons to peck one button (same) after the successive presentation of 16 identical pictures and to peck a second button (different) after the successive presentation of 16 nonidentical pictures. Later, we tested the birds with other lists ofsame anddifferent items composed of completely novel pictures. Accuracy to the testing lists reliably exceeded chance levels, thus demonstratingsame-different conceptualization by pigeons under conditions that, for the first time, (1) eliminated purely perceptual mechanisms of discrimination learning and transfer and (2) required memory-based processing of the experimental stimuli.     

Emotional Salience and the Isolation Effect

When a homogeneous list contains a few items that are different from the rest of the items in the list, these isolated items show enhanced recall compared to the same items in a list where these items are not isolated. This phenomenon, known as the isolation effect, has been explained on the basis of isolated items eliciting salience. In this experiment, negative pictures and neutral pictures were isolated at the early and late part of the list. The salience explanation would predict that participants would pay more attention to these isolated items resulting in higher judgments of learning (JOL) ratings compared to the same items in the control list. Negative pictures showed the isolation effect for both early and late isolation; however, for early isolation, JOL was similar between the isolated and non-isolated pictures indicating that the emotional isolation effect does not require emotional salience.     

强大的错误记忆效应:词表呈现时间与呈现方式的影响

本研究采用DRM范式(Deese-Roediger-McDermott paradigm),考察了词表项目的呈现时间与呈现方式对错误记忆效应的影响。结果发现,被试对关键诱饵的错误再认受到学习阶段词表项目的呈现方式的影响,表现为所有项目随机呈现条件下的错误再认明显低于分组呈现条件,尤其是在20ms的随机呈现条件下,观察到了对关键诱饵的最低错误再认率。说明在对词表项目的编码阶段产生了对关键诱饵的连续激活,而对关键诱饵的错误记忆则是基于连续激活的不断累积的结果,当词表项目的随机呈现阻断了连续激活过程时,便会有效降低错误记忆效应。而且,在所有实验条件下均发现了错误记忆效应产生中所伴随的强烈主观体验,证实了错误记忆是一种强大的效应。     

图片部分线索效应的学习时间分配的发展

部分线索效应指让学习者学习一系列材料, 在随后的测试阶段, 给学习者提供先前所学材料的一部分作为提取线索, 让其回忆剩余的材料, 回忆成绩反而比没有提取线索时回忆成绩差的现象。通过3个实验, 以图片为实验材料, 考察了图片部分线索效应学习时间分配的发展特点。实验1考察了图片部分线索效应的边界条件, 结果发现：图片学习中, 以物体名称为线索时, 不存在部分线索效应; 而以图片为线索时, 存在部分线索效应。结果表明：跨域线索是图片部分线索效应的边界条件。实验2利用图片作线索, 考察了图片部分线索效应的发展特点, 结果发现：图片学习中, 不同年龄被试均存在部分线索效应。结果表明：年龄不是图片部分线索效应的边界条件。实验3考察不同年龄被试对部分线索消极作用的记忆监控的发展变化趋势, 结果发现：小学二年级儿童即使经过多次学习, 也不能意识到部分线索的消极作用; 小学五年级儿童经过二次学习后, 方可意识到这种消极作用, 并在部分线索条件下安排了更多的学习时间; 初二和高二年级学生经过一次学习, 即可意识到部分线索的消极作用, 他们均在部分线索条件下安排了更长的学习时间。结果表明：儿童的学习时间分配决策能力在小学二年级到小学五年级之间有一个质的提高; 与初二学生相比, 高二学生对部分线索带来的消极影响做了更多的时间补偿。     

Information-seeking behavior: exploring metacognitive control in pigeons

Metacognitive control may occur if an organism seeks additional information when the available information for solving a problem is inadequate. Such information-seeking behavior has been documented in primates, but evidence of analogous behavior is less convincing in non-primates. In our study, we adopted a novel methodological approach. We presented pigeons with visual discriminations of varying levels of difficulty, and on special testing trials, we gave the birds the opportunity of making the discrimination easier. We initially trained pigeons on a discrimination between same and different visual arrays, each containing 12 items (low difficulty), 4 items (intermediate difficulty), or 2 items (high difficulty). We later provided an “Information” button that the pigeons could peck to increase the number of items in the arrays, thereby making the discrimination easier, plus a “Go” button which, when pecked, simply allowed the pigeons to proceed to their final discriminative response. Critically, our pigeons’ choice of the “Information” button increased as the difficulty of the task increased. As well, some of our pigeons showed evidence of prompt and appropriate transfer of using the “Information” button to help them perform brand-new brightness and size discrimination tasks. Speculation as to the contents of pigeons’ private mental states may be unwarranted, but our pigeons did objectively exhibit the kind of complex, flexible, and adaptive information-seeking behavior that is deemed to be involved in metacognitive control.     

The dual effect of context on memory of related and unrelated themes: Discrimination at encoding and cue at retrieval

The influence of contextual factors on encoding and retrieval in recognition memory was investigated using a retroactive interference paradigm. Participants were randomly assigned to four context conditions constructed by manipulating types of presentation modality (pictures vs words) for study, interference, and test stages, respectively (ABA, ABB, AAA, & AAB). In Experiment 1 we presented unrelated items in the study and interference stages, while in Experiment 2 each stage contained items from the same semantic category. The results demonstrate a dual role for context in memory processes-at encoding as well as at retrieval. In Experiment 1 there is a hierarchical order between the four context conditions, depending on both target-test and target-interference contextual similarity. Adding a categorical context in Experiment 2 helped to specify each list and therefore better distinguish between target and interferer information, and in some conditions compensated for their perceptual similarity.     

Repetition and laterality effects on recognition memory for words and pictures*

Recognition memory for a list of words was tested by presenting a series of items with Ss instructed to make positive responses to targets (list items) and negative responses to distractors (nonlist items). The test items were either words or pictures, and they were presented tachistoscopically either to the left or right visual field. The results showed mean response latencies to be generally faster for stimuli presented to the right visual field. Response times were faster for target and distractor stimuli on their second test presentations than on initial tests, but this effect was much larger for targets. Repetitions were shown to decrease the amount of time necessary to execute the stimulus encoding and initial retrieval stages of recognition. This was also true, although to a lesser extent, if different stimulus forms (words or pictures) were used on the two tests. Subsequent recognition stages, including memory search and decision processes. were apparently independent of test stimulus form.     

Separating central mechanisms by POCs: Evidence for an input—output buffer

Four experiments were performed, in each of which two sub-lists of items were presented for later recall, with varying priorities for success on each of the lists. All showed a trade-off, indicating that at some point the two lists were using the same mechanisms. In the two cases where presentation was simultaneous, however, the effects of priority interacted with those of recall order—that is, the items recalled first showed a larger effect of priority than did those recalled second. In the two cases where one sub-list arrived after the other, the low-priority items gave just as large an effect of recall order as the high-priority items. The second list presented did, however, show a larger effect of recall order than the first list presented. It is argued that the systems shared between two sublists involve some representations that are not disturbed by output, as well as an input—output buffer. The latter can hold a little extra information temporarily, but is disturbed by output; for successive lists it is dedicated largely to the most recently received list, but for simultaneous lists it is shared between the two lists in proportion to priority.     

Memory for instances and categories in children and adults

College subjects and 7-year-olds were trained in sorting 16 words into two conceptual categories. Training consisted of either three list presentations (Experiment I) or training to solution (Experiment II). Then either immediately or after a 3 to 4 week delay subjects received a recognition test which assessed memory for the instance vs categorical properties of the task stimuli by embedding words from the original list and from the list categories with confusion items from either the same or different categories as those on the original list. The data indicated that learning and memory were controlled primarily by categorical properties of the task items in adults and by specific instance properties in children. However, there was evidence that children had learned the categorical attributes of the task and may have differed from adults chiefly in their failure to utilize these attributes to assist learning and memory performance. The age differences in learning and memory were independent of the degree of initial training.     

The within-list distributed practice effect: Tests of the varied context and varied encoding hypotheses

The present studies provided separate tests of the varied context and varied encoding hypotheses of the MP-DP effect. The investigation of varied encoding used an incidental learning procedure in which the nature of the orienting task was manipulated such that the subject attended to different attributes of words (varied encoding) or only one attribute (same encoding). While the prediction that the recall of MP-DP items should be comparable under comparable levels of encoding was not supported, differences were obtained in recall of items under same and variable orienting task conditions. An MP-DP effect was obtained under the incidental learning procedure. Tests of varied context involved the presentation of target items in list contexts which were the same or different from list contexts on previous occurrences of the item. The prediction that recall of items surrounded by different context should exceed that of items surrounded by the same context was not supported.     

Auditory and visual spatial working memory

A series of experiments compared short-term memory for object locations in the auditory and visual modalities. The stimulus materials consisted of sounds and pictures presented at different locations in space. Items were presented in pure- or mixed-modality lists of increasing length. At test, participants responded to renewed presentation of the objects by indicating their original position. If two independent modality-specific and resource-limited short-term memories support the remembering of locations, memory performance should be higher in the mixed-modality than in the pure-modality condition. Yet, memory performance was the same for items in both types of list. In addition, responses to the memory load manipulation in both modalities showed very similar declines in performance. The results are interpreted in terms of object files binding object and location information in episodic working memory, independently of the input modality.     

Learning to reproduce a list and memory for the learning.

The ability to reproduce from memory a short list of verbal items immediately following presentation is known to improve over successive trials on that list, even if these trials are embedded in a sequence of trials on other lists of the same sort (Hebb, 1961). Less clear is whether this "Hebb effect" arises without the list repetition being noticed. This question has long been pondered and has recently taken on particular theoretical significance, but the available evidence is scant and inconsistent. Two experiments are described in which, in essence, a sequence of immediate reproduction trials was followed by tests that called for list recognition (Experiments 1 and 2) and/or estimates of list presentation frequency (Experiment 1). These tests provided quantitative measures of repetition awareness. Typical Hebb effects were found, but there was no evidence that the effects occurred without the subjects' being aware of the repetition; effect-size analyses indicated that both the recognition and frequency responses were more sensitive to repetition than were the reproduction responses. Therefore, not only could the recognition and frequency responses not have been made solely on the basis of how readily the test lists were reproduced, but the Hebb effect could have required an awareness of repetition.     

Monkey memory: same/different concept learning, serial probe acquisition, and probe delay effects

Three rhesus monkeys were trained and tested in a same/different task with six successive sets of 70 item pairs to an 88% accuracy on each set. Their poor initial transfer performance (55% correct) with novel stimuli improved dramatically to 85% correct following daily item changes in the training stimuli. They acquired a serial-probe-recognition (SPR) task with variable (1-6) item list lengths. This SPR acquisition, although gradual, was more rapid for the monkeys than for pigeons similarly trained. Testing with a fixed list length of four items at different delays between the last list item and the probe test item revealed changes in the serial-position function: a recency effect (last items remembered well) for 0-s delay, recency and primacy effects (first and last list items remembered well) for 1-, 2-, and 10-s delays, and only a primacy effect for the longest 30-s delay. These results are compared with similar ones from pigeons and are discussed in relation to theories of memory processing.     

Predicting the relative efficacy of three presentation methods for assessing preferences of persons with developmental disabilities

Choices were presented to 9 individuals with developmental disabilities using a two-choice format. Each pair of items, selected based on prior preference assessment, was presented to each participant in three conditions (actual items, pictures of the items, and spoken-name presentation) using a reversal design. The evaluation was conducted using food items, and was then repeated using nonfood items. The participants were also given a test to measure their skills on discrimination tasks ranging in difficulty from simple to conditional discriminations. The participants' abilities to make consistent choices with food and nonfood items were predicted, with 94% accuracy, by their discrimination skills. The findings suggest that presentation methods can affect the accuracy of a choice assessment, and that the systematic assessment of basic discrimination skills can be used to predict the effectiveness of different presentation methods in this population.     

Knowing what to remember and forget: A developmental study of cue memory in intentional forgetting

These experiments are the first to investigate children’s encoding and use of information about a memory cue in Bjork’s (1972) intentional forgetting task. In Experiment 1, children in Grades 2, 4, and 6 and college students were given cues to either remember or forget after the presentation of each picture. Recall and recognition tests of pictures and cues followed. The procedure in Experiment 2 was identical to that in Experiment 1 except that the list of presentation pictures was altered for some children (Grades 3 and 4) and adolescents (Grades 8 and 9) so that remember and forget cues were associated with particular taxonomic categories. In Experiment 3, the testing component was modified so that children (Grades 2, 3, and 4) and college students were asked to recall only the cue associated with each picture. The results indicated that (1) children as young as second graders encode the cue associated with each picture, although to a lesser extent than do college students, (2) much improvement in intentional forgetting is still occurring during adolescence, (3) only adults adequately cluster their recall by cue, (4) associating remember and forget cues with items from different categories does not increase the differentiation between cues, and (5) eliminating picture recall and recognition has minimal effects on the magnitude of cue judgments. These results suggest that children’s difficulties on intentional forgetting tasks stem, at least in part, from their poorer encoding of information about whether an item should be remembered or forgotten.     

Thematic elaboration and proximity in childrens recall, organization, and long-term retention of pictorial materials.

Preschool and fifth-grade children were asked to learn and recall lists of nine pictures of common objects in which the thematic relationship and the physical proximity of subsets of items were varied. Five presentation conditions (lists) were employed: (1) subgroups of three items simultaneously presented with an explicit theme, (2) the same items as in (1) but randomly arranged in the subset, (3) unrelated items presented simultaneously in groups of three, (4) nine items presented successively but temporally blocked in subgroups of three, and (5) nine items displayed successively in a random arrangement. Recall and clustering scores indicated that the older children spontaneously elaborated pictures when subsets of items were presented simultaneously and when these items formed a natural theme. The preschool children failed to elaborate, responding more on the basis of the proximity of the items. Proximity was a potent recall cue for both age groups. Long-term tests, carried out after one week, showed good retention, the output organization of which closely paralleled that observed during original learning.     

Pictorial encoding reduces false recognition of semantic associates

High levels of false recognition can be observed after people study lists of semantic associates that all converge on a nonpresented lure word. To test the idea that encoding distinctive perceptual information would help to reduce false recognition, we presented a line drawing representing each associated word during study list presentation and later tested recognition of studied words and lure words. Two experiments revealed marked reductions in false recognition after pictorial encoding, relative after to word encoding. Results suggest that people reject related and unrelated lures because these items lack the distinctive qualities associated with remembered pictures.     

An experimental analysis of memory processing

Rhesus monkeys were trained and tested in visual and auditory list-memory tasks with sequences of four travel pictures or four natural/environmental sounds followed by single test items. Acquisitions of the visual list-memory task are presented. Visual recency (last item) memory diminished with retention delay, and primacy (first item) memory strengthened. Capuchin monkeys, pigeons, and humans showed similar visual-memory changes. Rhesus learned an auditory memory task and showed octave generalization for some lists of notes--tonal, but not atonal, musical passages. In contrast with visual list memory, auditory primacy memory diminished with delay and auditory recency memory strengthened. Manipulations of interitem intervals, list length, and item presentation frequency revealed proactive and retroactive inhibition among items of individual auditory lists. Repeating visual items from prior lists produced interference (on nonmatching tests) revealing how far back memory extended. The possibility of using the interference function to separate familiarity vs. recollective memory processing is discussed.     

Adapting to an irrelevant item in an immediate recall task

Recall of the last one or two items of a spoken list is impaired when the list is followed by a nominally irrelevant item. At issue here was whether this suffix effect is reduced with repeated exposure to the irrelevant item. The effect was found to decline over successive blocks of trials, but only slightly (Experiment 1). No decisive evidence for adaptation to the irrelevant item was found when it was spoken after each of the list items rather than after the last one only (Experiments 2 and 3). The strongest evidence for adaptation was obtained when the irrelevant item was repeated in an unbroken stream that extended through the presentations and recall periods of successive lists: The recency effect and the level of recall at the last position within a list were greater under these conditions than when the irrelevant item was presented only once after each list (Experiments 4, 5, and 6).     

Free recall and retrieval speed of categorized items by kindergarten children

Kindergarten Ss were presented with 16 pictorial items in four category sets or a partially random ordem with one item from each category composing the four presentation sets. The pictures were presented either on conceptually related background pictures or on white backgrounds. The categorically grouped presentation facilitated free recall performance, both in terms of number of items recalled and the speed with which the items were recalled, and increased the amount of clustering in recall. Categorical clustering in recall was associated with shorter within- than between-category intervals and for those Ss who recalled items from each of four categories successively, the over-all temporal pattern in recall closely approximated that found with adults. No background effects were found.