Stimulus redundancy and immediate recall

This study examined immediate recall in two stimulus prefix and two stimulus suffix conditions and in a condition that combined a prefix and suffix. Suffixes and the combination of a prefix with a suffix interfered more with recall overall than did prefixes. Performance in each of the conditions that included a prefix was significantly better overall than in appropriate control conditions, in which interference was augmented by a redundant element in recall. It was suggested that prefixes and suffixes lie operationally on a continuum and that their effects result from the subject's inability to dissociate the redundant element from the memory series. However, the location of redundancy imposes different processing requirements that differentially influence recall.     

“Next-to-nothings” and nothingness: A study of attention, attenuation and the stimulus prefix effect

The stimulus prefix effect, in which a non-recallable item placed at the beginning of a to-be-remembered string of items creates interference, was studied using a 1-s simultaneous visual method of presentation. Two variants on the standard prefix condition were used; in one, the prefix, o, was presented in a different colour from the memory string of seven digits and, in the other, the prefix consisted of three identical zeroes. The three prefix conditions were compared with two control conditions in which either seven or eight digits were presented. No evidence of prefix effects was found in the recall data over serial positions 1-4, for which retrieval was highly efficient, and it was concluded that the action of response set may exclude the prefix from a response buffer (c.f. Morton, 1970). There was also no evidence that the specialized prefixes led to an attenuation of the interference found in the remaining positions. The latter finding is considered to be contrary to a unit-formation hypothesis (Kahneman, 1973) but is consistent with a mode of operation of the logogen model (Morton, 1970).     

Articulatory organization in the prefix effect

Neisser, Hoenig, and Goldstein (1969) reduced the “stimulus prefix effect” (diminished recall of seven digits preceded by a redundant prefix) when the redundant prefix and the recall digits were produced by different speakers. In the present studies, similar results were obtained using one speaker only, but with the prefix and recall digits spoken separately in different utterances and combined by tape splicing. The results support a hypothesis concerning the perception of intact, wholistically organized articulatory units. A second hypothesis, also based on the idea of intact articulatory units, was tested.     

The stimulus suffix effect as a memory coding phenomenon

Two short-term memory experiments examined the nature of the stimulus suffix effect on auditory linguistic and nonlinguistic stimulus lists. In Experiment 1, where subjects recalled eight-item digit lists, it was found that a silently articulated digit suffix had the same effect on recall for the last list item as a spoken digit suffix. In Experiment 2, subjects recalled lists of sounds made by inanimate objects either by listing the names of the objects or by ordering a set of drawings of the objects. Auditory suffixes, either another object sound or the spoken name of an object, produced a suffix effect under both recall conditions, but a visually presented picture also produced a suffix effect when subjects recalled using pictures. The results were most adequately explained by a levels-of-processing memory coding hypothesis.     

Stimulus array and recall method as variables in audio-visual split-span memory

Performance on an audio-visual split-span task was found to be adversely affected by the concurrent operation of two factors, namely: alternation of stimulus classes between the two input messages, and the use of a recall method which entails alternate sampling of the two messages. However, these factors had no significant effect when operating singly. The present study indicated that subjects prefer the strategy of reporting visual items first when using modality recall, and that this strategy is more efficient than that of reporting auditory items first. Also, modality recall proved to be the preferred method under free recall instructions. While there were more visual errors than auditory errors, visual commissions exceeded order errors, but auditory order errors exceeded commissions. The redundancy proposal of the search hypothesis (Yntema and Trask, 1963) was tested, and was found to be inadequate as an account of audio-visual performance.     

The Ranschburg effect: Stimulus variables and scoring criterion*

The influence of stimulus variables on recall of intraserially repeated items was investigated with a parametric manipulation of the rate of presentation (.4, .8, or 1.6 sec/item), modality of presentation (auditory or visual), and sequence length (7 or 10 items long). The results indicated that the Ranschburg effect, poorer recall of repeated items than of corresponding control items, is relatively insensitive to stimulus manipulations. The Ranschburg effect was found to be localized primarily at the position of the second occurrence of the repeated item. The influence of the repeated items did not generalize to the other (nonrepeated) items of the sequence. Differences in the Ranschburg effect as a function of the scoring criterion were discussed. The results were interpreted as being consistent with a guessing bias interpretation of the Ranschburg effect.     

感知觉加工与概念加工对联结记忆中图片优势效应的影响

本研究采用联结再认范式考察联结记忆中感知觉水平和概念加工程度对图片优势效应的影响。实验1通过呈现清晰或模糊的词语或图片对操纵了感知觉水平,结果发现只有在清晰条件下图片优势效应才会出现;实验2则在模糊条件下通过要求被试想象两个项目之间的关系操纵了概念加工程度,结果发现在有概念加工条件下,出现了图片优势效应。研究结果表明：（1）降低的感知觉水平会导致联结记忆中的图片优势效应消失;（2）对模糊项目对进行概念加工会使联结记忆中出现图片优势效应。     

Developmental changes in word attribute utilization for organization and retrieval in free recall

The development of two distinct but related activities in free recall: organization and retrieval, was examined in relation to the development of memory attributes. Twenty-five words printed on cards were chosen to be cross-classified according to conceptual category and according to acoustic similarity. Second-graders (8 year olds), sixth-graders (12 year olds), and college students (20 year olds) either sorted the stimulus words as they wished, were yoked to another subject's sort, or were instructed to sort the words in a blocked fashion according to one attribute or the other. Age differences in attribute preference for sorting were found, as well as significant interactions between age level and attribute basis for mean recall-within-categories, for cued recall, and for clustering in free recall. The results lend strong support to the theory that attribute dominance does in fact change as a function of age, in terms of both organizational schemes and the role of these schemes for recall, and suggest that psychologists reexamine the present notions of children's organizational skills in recall tasks.     

Dissociating the effects of featural and conceptual interference on multiple target processing in rapid serial visual presentation

Attentional blink (AB) describes the finding that, when subjects attend to a specified target in a rapidly presented visual stream, they show a decreased ability to process a subsequent probe item for up to 600 msec. In the present study, the roles of featural and conceptual interference in the processing of targets and probes in a rapid serial visual presentation stream were examined. In Experiment 1, featurally more complex T + 1 items produced larger AB even when the physical energy of the stimulus (e.g., the number of pixels) was held constant. In Experiment 2, the conceptual category of the T + 1 item affected target identification but not AB magnitude. These result suggest that featural interference is a major determinant of AB magnitude, whereas featural and conceptual interference both affect target identification.     

The suffix effect: How many positions are involved?

Three experiments tested the effect of the availability of the last item on the recall performance for earlier list items in a stimulus suffix paradigm. A decrement due to the suffix occurred for preterminal positions even when the last item was made available. This preterminal suffix effect was found to be more extensive in a condition in which subjects were free to recall the end items first than in a condition in which subjects were forced to recall in a strict left-to-right fashion.     

Enhancement of 4-year-old children's memory span for phonologically similar and dissimilar word lists

Previous research suggests that preschool children are deficient in rehearsal and that stimulus list repetitions can improve their recall, presumably by substituting for the products of rehearsal. However, the previous research included interitem or postlist retention intervals of several seconds or more. We examined the utility of list repetitions with reference to an ordinary span task in which spoken words were presented 1 s apart for immediate recall. Lists with phonologically similar versus dissimilar items were included, to determine if the overall pattern of recall could be made more similar to what is ordinarily obtained in older children. Cumulative repetition was found to cause a moderate increase in both memory span and the phonological similarity effect. Other types of list repetition provided more insight into types of stimulus redundancy that were helpful (e.g., repeated serial order information) or not helpful (e.g., forced articulatory coding) to children attempting to recall spoken lists. The underlying mnemonic processes are discussed.     

Differential effects of repetition on pre- and postcategorical memory traces

The effect of list repetition on immediate recall for aurally presented nine-letter lists was studied under two conditions. In the first, a redundant stimulus item was presented as the tenth item in each list, while the suffix was not included in a control condition. As in previous research (Crowder & Morton, 1969), the stimulus suffix selectively interfered with recall at the terminal presentation serial positions, indicating the presence of precategorical acoustic storage. Repetition had a nonselective effect on performance. This result and an analysis of acoustic errors support the inference that qualitative differences in the memory code may lead to differences in other functional properties of the memory trace, such as responsiveness to repetition.     

Redundancy gains and costs in cognitive processing: effects of short stimulus onset asynchronies

In 7 experiments, the influence of varying stimulus onset asynchronies (SOAs) on the processing of redundant information about words and pseudowords was investigated. All stimuli were visually presented once or twice with 2 copies of the same item flashed either simultaneously or with short SOAs between presentations. The experiments revealed a redundancy gain for words that was absent for pseudowords. Furthermore, the redundancy gain disappeared at an SOA of 50 ms, and there was a gradual performance decline at longer SOAs. However, probing SOAs of 150 and 300 ms revealed that, compared with presentation of 1 target stimulus alone, words were processed significantly faster when target and redundantcopy appeared with a 150-ms lag. The results are tentatively explained in a neurocognitive framework.     

Word length and age influences on forward and backward immediate serial recall

The present research is aimed at understanding the processes involved in short-term memory and how they interact with age. Specifically, word length effects were examined under forward serial recall, backward serial recall, and item recognition tasks, with performance being interpreted within an item-order theoretical framework. The interaction of age, word length, and direction of recall was examined in two experiments, the first of which confirmed that the word length was present with forward recall and absent with backward recall. In addition, age effects were stronger in backward recall than in forward recall. In the second experiment, an item-order trade-off methodology was utilized with backward recall. When order memory was required, there was no word length effect and strong age effects. When memory was tested via an item recognition test, there was a reverse word length effect and no age effect. While word length effects can be interpreted within the item-order framework, age effects cannot.     

Positional and temporal clustering in serial order memory

The well-known finding that responses in serial recall tend to be clustered around the position of the target item has bolstered positional-coding theories of serial order memory. In the present study, we show that this effect is confounded with another well-known finding—that responses in serial recall tend to also be clustered around the position of the prior recall (temporal clustering). The confound can be alleviated by conditioning each analysis on the positional accuracy of the previously recalled item. The revised analyses show that temporal clustering is much more prevalent in serial recall than is positional clustering. A simple associative chaining model with asymmetric neighboring, remote associations, and a primacy gradient can account for these effects. Using the same parameter values, the model produces reasonable serial position curves and captures the changes in item and order information across study-test trials. In contrast, a prominent positional coding model cannot account for the pattern of clustering uncovered by the new analyses.     

The development of the use of long-term knowledge to assist short-term recall

The influence of item familiarity upon memory span was examined in adults and children aged 5, 7, and 10 years by comparing the recall of words and nonwords. Using a probed recall task, both item recall and position recall were tested. The effect of familiarity upon item recall was found to develop with age, from no effects in the 5-year-olds to significant effects in the older children and adults. By contrast, no effect of familiarity was found at any age when recall of position was required. Dissociations between word length effects and familiarity effects supported the conclusion that the familiarity effect does not result from rehearsal. Several explanations for the source of the familiarity effect were examined, and the familiarity effect was attributed to a strategic redintegration or reconstruction process, which is necessary for item recall but not for position recall.     

The stimulus suffix: A paradoxical effect

Two experiments are reported which showed that a stimulus suffix word, following eight words presented for immediate serial recall, affected recall performance differentially for the final list word: the target word. The observed difference depended on whether the target word and suffix were associated. It was concluded that both the target word and the redundant stimulus suffix were coded at the level of semantic coding as well as at the level of acoustic coding, and that an effect resulted where none had previously been found. There was no evidence to indicate that the coding of the semantic features required a switch in attention to the target word during the presentation of the list, and the coding for this was presumed to be autonomous. A model was described to explain the paradoxical effect of an associated stimulus suffix.     

Dissociable lexical and phonological influences on serial recognition and serial recall

The impact of the lexicality of memory items on memory performance was compared in two paradigms, serial recall and serial recognition. Experiments 1 to 3 tested 7- and 8-year-old children. Memory accuracy was only mildly impaired in lists containing nonwords compared with words in a serial recognition task involving judgements of whether the items in two sequences were in the same order (Experiment 1), although a substantial advantage for word over nonword items from the same stimulus pool was found in serial recall (Experiment 2). A stronger influence of lexicality on serial recall than serial recognition was further demonstrated in Experiments 3A and 3B, and in 4A and 4B using adult participants. These experiments also established comparable degrees of sensitivity to the phonological similarity of the memory sequences in the two paradigms. The phonological similarity effect in serial recall was found to arise from increased phoneme order errors, whereas the lexicality effect was due principally to the greater frequency of phoneme identity errors for nonwords. It is proposed that the lexicality effect originates in the redintegration of item information just prior to recall, and that this process is largely bypassed in serial recognition.     

Recognition latency for pictures and words as a function of encoded-feature similarity.

In separate trials of a same-different recognition task, a single target item presented as either a picture or a word was followed after a 30-sec delay by a single test item, either a picture or a word. Test items were either nominal matches for the target (same) or one of five related distractor items. Distractors were selected to resemble the target item on one of five dimensions: orthographic, acoustic, conceptual (functional or categorical), schematic (similar in shape), or neutral. Same-different reaction times were found to vary systematically as a function of depiction mode of target and/or test items and by distractor type. Verbally related distractors (orthographic and acoustic) produced longer reaction times when target or test items or both were presented as printed words. When target or test items were presented as pictures, schematic and conceptual distractors produced the longest rejection latencies.     

Implicit and explicit memory without awareness

Summary Three experiments are reported which investigate the conscious status of subjects during an implicit-memory test. In all experiments the subjects either named each visually presented target item or generated each item from an anagram in a first phase of incidental learning. In a second phase, they were either given a visual word-stem completion task as an implicit-memory test or given a recognition task (Experiment 1), or a cued-recall task (Experiments 2 and 3) as explicit-memory tests. Finally, in a third phase the subjects were required to make decisions about the input status (i. e., they had to decide whether the item was present in the first phase) as well as about the output status of information (i. e., they had to decide whether the item had been completed, recognized or recalled in the second phase). A generation effect (i. e., generated items were remembered better than named items) was evident in the recognition and recall data, but only for items whose recognition or recall was accompanied by conscious recollection of their previous occurrence in the study list. Judgments about the input status were more precise, given that items had been consciously recognized or recalled rather than completed. The same pattern of findings was observed for judgments about the output status. The results are interpreted as evidence that subjects in implicit-memory tests are less aware of the fact that some of their productions are relevant to prior experiences. In addition, they are less aware of the fact that they are retrieving information from their memories. However, the same state of nonawareness may be present in explicit-memory tests, as was revealed by the performance of subjects on those items whose recognition or recall was not accompanied by conscious recollection.