The effects of interference tasks on recency in the free recall of action events

Summary Lists of verbal instructions were read aloud and each was enacted either by the subject (SPTs) or by the experimenter (EPTs). In Experiment 1 free recall was made of lists of SPTs and EPTs either immediately after presentation, after an empty 20-s delay interval, or after a 20-s delay interval filled with backward counting. The recall of recency items was unaffected by the empty delay interval, but was somewhat reduced by the counting task. In Experiment 2 free recall was made of lists of SPTs and EPTs either immediately after presentation or after a delay that was filled with a single SPT or a single EPT, 20 s in length. The recency effect evident in the immediate-recall condition was virtually wiped out in the delay conditions, irrespective of whether the delay task matched those in the free-recall list or not. These results are discussed in terms of the mnemonic similarity of the two types of action event.     

Modality effects in delayed free recall and recognition: Visual is better than auditory

During presentation of auditory and visual lists of words, different groups of subjects generated words that either rhymed with the presented words or that were associates. Immediately after list presentation, subjects recalled either the presented or the generated words. After presentation and test of all lists, a final free recall test and a recognition test were given. Visual presentation generally produced higher recall and recognition than did auditory presentation for both encoding conditions. The results are not consistent with explanations of modality effects in terms of echoic memory or greater temporal distinctiveness of auditory items. The results are more in line with the separate-streams hypothesis, which argues for different kinds of input processing for auditory and visual items.     

The effect of word length in short-term memory: Is rehearsal necessary?

Three experiments investigated the effect of word length on a serial recognition task when rehearsal was prevented by a high presentation rate with no delay between study and test lists. Results showed that lists of short four-phoneme words were better recognized than lists of long six-phoneme words. Moreover, this effect was equivalent to that observed in conditions in which there was a delay between lists, thereby making rehearsal possible in the interval. These findings imply that rehearsal does not play a central role in the origin of the word length effect. An alternative explanation based on differences in the degree of retroactive interference generated by long and short words is proposed.     

The effect of word length in short-term memory: Is rehearsal necessary?

Three experiments investigated the effect of word length on a serial recognition task when rehearsal was prevented by a high presentation rate with no delay between study and test lists. Results showed that lists of short four-phoneme words were better recognized than lists of long six-phoneme words. Moreover, this effect was equivalent to that observed in conditions in which there was a delay between lists, thereby making rehearsal possible in the interval. These findings imply that rehearsal does not play a central role in the origin of the word length effect. An alternative explanation based on differences in the degree of retroactive interference generated by long and short words is proposed.     

On the nature of talker variability effects on recall of spoken word lists.

In a recent study, Martin, Mullennix, Pisoni, and Summers (1989) reported that subjects' accuracy in recalling lists of spoken words was better for words in early list positions when the words were spoken by a single talker than when they were spoken by multiple talkers. The present study was conducted to examine the nature of these effects in further detail. Accuracy of serial-ordered recall was examined for lists of words spoken by either a single talker or by multiple talkers. Half the lists contained easily recognizable words, and half contained more difficult words, according to a combined metric of word frequency, lexical neighborhood density, and neighborhood frequency. Rate of presentation was manipulated to assess the effects of both variables on rehearsal and perceptual encoding. A strong interaction was obtained between talker variability and rate of presentation. Recall of multiple-talker lists was affected much more than single-talker lists by changes in presentation rate. At slow presentation rates, words in early serial positions produced by multiple talkers were actually recalled more accurately than words produced by a single talker. No interaction was observed for word confusability and rate of presentation. The data provide support for the proposal that talker variability affects the accuracy of recall of spoken words not only by increasing the processing demands for early perceptual encoding of the words, but also by affecting the efficiency of the rehearsal process itself.     

Effects of list length and first-trial reward upon concurrent discrimination performance

Rhesus monkeys were given 2304 two-trial object discrimination problems that were presented as members of lists consisting of two, four, or eight problems. The problems within each list were presented concurrently, Trial 1 for all problems in the list being presented before initiation of Trial 2 for any problem. Each problem involved exposure of a single object on Trial 1, which was either rewarded or not rewarded, followed by presentation of the Trial 1 object along with a second object on Trial 2. Performance varied inversely with list length, and this effect became more prominent as a function of training. Performance after Trial 1 nonreward was substantially better than that after Trial 1 reward, and this effect became enhanced both with continued training and with increased list length. The findings were discussed in terms of Bessemer's short-term memory analysis of learning set.     

The influence of selection for response on repetition priming of word identification.

Repetition priming of word identification was examined using study tasks that required participants either to search for targets appearing in rapid serial visual presentation of word lists or to read aloud a list of target words. Nontarget words embedded in search lists produced a small amount of repetition priming on a masked word identification test, independent of presentation duration in the search list (200-1,000 ms), but no priming when they appeared as targets in a second search task used at test. For both test tasks, words that were originally encoded in a read-aloud task or served as detected targets during a search task generated more priming than nontarget words from search lists. These results suggest that priming effects are strongest when study tasks require an item to be selected as the basis for an overt response, even though the information on which study and test responses are based may be different.     

Examining the relationship between free recall and immediate serial recall: Similar patterns of rehearsal and similar effects of word length,presentation rate,and articulatory suppression

In five experiments, rehearsal and recall phenomena were examined using the free recall and immediate serial recall (ISR) tasks. In Experiment 1, participants were presented with lists of eight words, were precued or postcued to respond using free recall or ISR, and rehearsed out loud during presentation. The patterns of rehearsal were similar in all the conditions, and there was little difference between recall in the precued and postcued conditions. In Experiment 2, both free recall and ISR were sensitive to word length and presentation rate and showed similar patterns of rehearsal. In Experiment 3, both tasks were sensitive to word length and articulatory suppression. The word length effects generalized to 6-item (Experiment 4) and 12-item (Experiment 5) lists. These findings suggest that the two tasks are underpinned by highly similar rehearsal and recall processes.     

Vocalization-at-presentation and immediate recall, with varying presentation-rates

An experiment is reported in which the subject read visually presented lists with four different degrees of vocalization; immediately after reading each list he was required to reproduce it either aloud or in writing. Each list consisted of eight consonants and presentation rates were varied between I and 4 letters per sec. For any given series of lists, the subject was asked either to read the letters silently, or to mouth them silently, or to whisper them, or to say them aloud while reading.

At the fastest presentation-rate immediate recall improved monotonically with the degree of vocalization during reading of the lists; at slower rates this generalization held less well, especially for the lower degrees of vocalization. Vocalization was most helpful at the highest presentation-rate.

The overall amount correctly recalled was better for more slowly presented lists and for written as opposed to spoken recall. Analysis of the errors suggested that acoustic confusions were affected by the conditions of presentation; and that serial order intrusions were independent of presentation-or recall-conditions. An apparent variation of transpositions with voicing-and-recall-method failed to reach statistical significance. Theoretical implications of the experiment are discussed, including reference to Broadbent's theory of short-term memory (1958).     

Effects of orthographic and phonological word length on memory for lists shown at RSVP and STM rates

This article reports 3 experiments in which effects of orthographic and phonological word length on memory were examined for short lists shown at rapid serial visual presentation (RSVP) and short-term memory (STM) rates. Only visual-orthographic length reduced RSVP serial recall, whereas both orthographic and phonological length lowered recall for STM lists in Experiment 1. Word-length effects may arise from output processes or from the temporal duration of output in recall. In 2 further experiments, output demands were reduced through the use of a recognition test. Recognition accuracy was impaired only by orthographic length for RSVP lists and by phonological length for STM lists in both experiments. The results demonstrate 2 item length effects not simply attributable to increased output time in recall, and implications for theories of STM are considered.     

Recall of short word lists presented visually at fast rates: Effects of phonological similarity and word length

Phonological similarity of visually presented list items impairs short-term serial recall. Lists of long words are also recalled less accurately than are lists of short words. These results have been attributed to phonological recoding and rehearsal. If subjects articulate irrelevant words during list presentation, both phonological similarity and word length effects are abolished. Experiments 1 and 2 examined effects of phonological similarity and recall instructions on recall of lists shown at fast rates (from one item per 0.114-0.50 sec), which might not permit phonological encoding and rehearsal. In Experiment 3, recall instructions and word length were manipulated using fast presentation rates. Both phonological similarity and word length effects were observed, and they were not dependent on recall instructions. Experiments 4 and 5 investigated the effects of irrelevant concurrent articulation on lists shown at fast rates. Both phonological similarity and word length effects were removed by concurrent articulation, as they were with slow presentation rates.     

Effect of list length on recall after dichotomous visual presentation

A visual analogue of an auditory dichotic listening experiment was carried out using what may be termed dichotomous visual presentation of lists of either three or four stimuli. Each stimulus consisted of several identical letters which were arranged so as to form the outline of a second, large letter. Subjects attended to either the small or large letters, and recalled either the attended or unattended letters first. It was found that the results for the three-stimulus and four-stimulus lists differed substantially; they were interpreted as consistent with the model of short-term memory proposed by Broadbent (1975).     

REPETITION DEAFNESS:

Abstract— This research demonstrates a new cognitive phenomenon known as repetition deafness, a difficulty in immediate recall of repeated words in computer-compressed speech Sixty-four subjects heard sentences and lists at four speeded rates 70, 55, 35, and 28 msl phoneme Each target word in the materials followed a pretarget word that was either identical (repeated-target condition) or different (unrepeated-target condition), and targets were harder to recall when repeated than unrepeated Repetition deafness was rate-limited, occurring only with rapid rates of presentation (55 mslphoneme or less), and decreased in magnitude as structure increased from lists to sentences Implications for current theories of repetition deficits are discussed     

Lexical coherence in short-term memory: Strategic reconstruction or “semantic glue”?

This study explores the foundation of lexical/semantic phoneme binding effects in verbal short-term memory (STM). The immediate serial recall of pure lists of words and nonwords was compared with the recall of mixed lists that had either a predictable, alternating structure (e.g., wnwnwn) or an unpredictable structure (i.e., the serial positions of the words/nonwords could not be known in advance). The study provides evidence for two separate mechanisms by which long-term linguistic knowledge contributes to STM. First, there was evidence for automatic lexical/semantic binding effects that were independent of knowledge of lexical status. The nonwords in both types of mixed list damaged word recall and encouraged the phonological elements of words to migrate. In both alternating and unpredictable mixed lists, the phonemes of words were more likely than the phonemes of nonwords to be recalled together as a coherent item, suggesting that lexical/semantic knowledge encourages the phonological elements of words to emerge together in immediate serial recall, even when lexical status is unknown. Secondly, there was evidence for “strategic redintegration”, which was dependent on prior knowledge of the lexical status of the items in mixed lists. When participants recalled items that they knew to be words in advance, they were able to use this knowledge to constrain their responses so that they were more likely to be lexically appropriate. These findings motivate modifications to current theories of the interaction between linguistic knowledge and verbal short-term memory.     

Does emotion help or hinder immediate memory? Arousal versus priority-binding mechanisms

People recall taboo words better than neutral words in many experimental contexts. The present rapid serial visual presentation (RSVP) experiments demonstrated this taboo-superiority effect for immediate recall of mixed lists containing taboo and neutral words matched for familiarity, length, and category coherence. Under binding theory (MacKay et al., 2004), taboo superiority reflects an interference effect: Because the emotional reaction system prioritizes binding mechanisms for linking the source of an emotion to its context, taboo words capture the mechanisms for encoding list context in mixed lists, impairing the encoding of adjacent neutral words when RSVP rates are sufficiently rapid. However, for pure or unmixed lists, binding theory predicted no better recall of taboo-only than of neutral-only lists at fast or slow rates. Present results supported this prediction, suggesting that taboo superiority in immediate recall reflects context-specific binding processes, rather than context-free arousal effects, or emotion-linked differences in rehearsal, processing time, output interference, time-based decay, or guessing biases.     

Memory for attended and unattended visual stimuli

Subjects were presented with lists of 'compound letters,' letters whose overall shapes were described by repeated use of replicates of other, smaller letters. In Experiment 1 subjects were asked to attend to either the overall letter or the smaller, constituent letter. At the end of list presentation, recall of all letters was required, but a postlist cue determined whether the attended or unattended letters were to be reported first. The results for four-item lists accorded with those of Martin (1978, 1980): order of report had a larger effect upon retention of attended letters than upon retention of unattended letters. The findings for three-item lists did not agree with Martin, however: first, the interaction of attention and order was weak; second, sharp recency for unattended letters was not found.

Experiment 2 required that subjects recall either in temporal pairs or by letter size. The results strongly suggest that the present paradigm does not constitute an analogue to dichotic listening. In particular, there is little evidence for a role for sensory retention of compound letters at time of recall.     

Rhythmic groups and subjective chunks in memory for melodies

Memory for brief melodic phrases was tested using a short-term recognition-memory paradigm. The five-note phrases were rhythmically separated from each other and presented in lists four phrases in length. A single five-note test item followed each list and either corresponded rhythmically to one of the phrases as presented in the list (within items) or to the last three notes of one phrase and the first two notes of the next (across items). Within items were easier than across items. Slow presentation (3 notes/sec) was slightly easier than fast (6 notes/see). The J-shaped serial position curve typical of short-term memory for verbal material was obtained. The results support the position that rhythmic grouping of input determines subjective chunking and memory storage, facilitating the recognition of test items chunked in the same way as list items.     

Time,space, and memory for order

Information about the order of items in a sequence can be conveyed either spatially or temporally. In the present investigation, we examined whether these different modes of presentation map onto compatible mental representations of serial order. We examined this issue in three immediate serial-recall experiments, in which participants recalled lists of letters in the temporal order in which they had appeared. Each letter in a to-be-remembered sequence was presented in a unique spatial position, with the order of these spatial positions progressing from either left to right or right to left. In this way, the visually presented lists contained both temporal and spatial order information. Recall of the temporal order information was more accurate with congruent spatial order information—that is, when the letters progressed from left to right, following the typical reading direction of English—than when the spatial order information was incongruent. These results suggest compatible representations of serial order when sequences are conveyed spatially and temporally.     

A developmental study of the Prelinguistic Auditory Store (PAS)

Lists of digits 5 and 7 items in length were presented to second graders, sixth graders, and low-IQ sixth graders in either the visual or auditory modality. Half the auditory lists were followed by the redundant nonrecalled, auditorily presented word “recall” which served as a list suffix. The second graders had the most errors in the ordered recall task followed by the low-IQ sixth- and normal sixth-graders in that order. The size of the modality and suffix effects for the various groups seemed to indicate that, for the younger subjects, a larger proportion of the recall after auditory presentation comes from the Prelinguistic Auditory Store than for the older subjects.     

The mixed truth about frequency effects on free recall: Effects of study list composition

The mixed-list paradox is the finding that high-frequency words show a recall advantage in blocked lists, but that this advantage is reversed or nullified in mixed lists. We argue that this paradox has been poorly defined. Specifically, researchers should investigate random and alternating lists separately. We examine blocked, random, and alternating lists in our experiment. We hypothesize that a low-frequency recall advantage could arise due to asymmetrically strong links between low- and high-frequency words. Supporting our hypothesis, a lowfrequency recall advantage is observed in the random list, as is an asymmetry of association. In the alternating list, no recall advantage is observed, and neither is any asymmetry of association. Our results offer a clear challenge to future research to (1) consider the associations between word frequencies and (2) consider random and alternating lists separately.