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 phonological similarity and concurrent irrelevant articulation on short-term-memory recall of repeated and novel word lists

The extent to which phonological similarity of list words impairs short-term-memory recall was investigated in two experiments. Experiment 1 showed that the phonological-similarity effect occurred both when list words were repeatedly sampled from a small set and when they were new on every trial, both when word-order information was required and when it was not. Furthermore, the adverse effect of phonological similarity on recall was apparent on the initial lists recalled, did not change over trials, and cannot be attributed to increasing levels of proactive inhibition across lists. In Experiment 2, subjects were required to count repeatedly to six during list presentation. Concurrent irrelevant articulation lowered recall and abolished the phonological similarity effect for both repeated and novel word lists.     

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.     

The influence of word frequency on recency effects in directed free recall

Leading theoretical explanations of recency effects are designed to explain the reported absence of a word frequency effect on recall of words from recency serial positions. The present study used a directed free-recall procedure (J. J. Dalezman, 1976) and manipulated the frequency composition of the word lists (pure and mixed). Overall, with pure lists, a greater proportion of high-frequency (HF) words were recalled than low-frequency (LF) words, and with mixed lists, a greater proportion of LF words were recalled than HF words. Of importance, this recall advantage for one frequency over the other as a function of list composition was evident across the last three serial positions, indicating an influence of word frequency on recency effects that is dependent on the frequency composition of the lists. These results challenge one of the major assumptions on which several theories of recency effects have been based.     

Role of study strategy in recall of mixed lists of common and rare words

Experiment 1 confirmed previous findings that common words are more recallable than are rare words when the 2 kinds of words are presented in separate lists but not when they are presented in the same list. Experiment 2 showed much the same pattern when an orienting task was performed during word presentation. In Experiment 3 common words were found to be more recallable than rare words even for mixed lists when no warning was given of the memory test, although the effect was less pronounced than for pure lists. In Experiment 4 stronger measures were taken to preclude anticipation of the memory test, and the effect of word commonness was found to be just as pronounced with mixed lists as it was with pure lists. It was suggested that lists are studied in a way believed to optimize recall and that mixed lists foster a strategy of favoring the rare words.     

Continued word associations and free recall

Two experiments on the short-term free recall of 12-word associated and non-associated lists are reported. Degree of association (derived from norms obtained by continuous controlled association) and word frequency were varied. Significant facilitation as a result of the associative manipulations was obtained and clustering of the responses was positively related to this. Clustering was also affected by the method of presentation of the associated words; this occurred more often when they were grouped in presentation than when they were presented randomly arranged among other words in the list. Low frequency associated word lists were generally found to be more efficiently recalled than those of comparable association values but consisting of high frequency words.     

工作记忆中汉语反词长效应机制

工作记忆中的反词长效应(reverse word-length effect)指在对长词和短词混合的词表进行即时序列回忆时, 独立长词回忆成绩优于独立短词的现象。以汉字词语为材料通过3个实验探讨反词长效应的机制。实验1采用纯粹词表和长短词混合词表, 既得到纯粹词词长效应, 也得到独立词反词长效应。实验2削弱了长短词之间的词长差异, 结果独立词反词长效应消失, 且独立词回忆成绩优于纯粹词。实验3设计了视觉延迟条件, 得到与实验1类似的结果, 只是独立词反词长效应有所削弱。三个实验的结果并不一致, 无法用现有的语音回路理论或SIMPLE理论进行很好地解释, 理论的整合与创新显得非常重要。因此, 提出多重编码以既相互竞争又相互补充方式进行平行加工的观点进行更完整地解释。     

Paradoxical effects of testing: Repeated retrieval attempts enhance the likelihood of later accurate and false recall

The testing effect is the finding that taking an initial test enhances the likelihood of later recall. The present report examines the extent to which this benefit of testing comes with a cost: an enhanced likelihood of erroneously recalling incorrect information. Subjects were given short lists of semantic associates (e.g., hill, valley, climb); each list converged upon a related nonpresented word (e.g., mountain). After presentation of some lists, the subjects received no initial test; after others, one initial free recall test; and after others, three successive free recall tests. The probabilities of final free recall (and the probability of reporting vivid recollection of the moment of encoding) of both studied and related, nonstudied words (e.g., mountain) were highest when three initial tests had been taken, intermediate following one initial test, and lowest when no initial test had occurred. The beneficial effects of testing carry the cost of increases in erroneous memory for related information.     

On the generality of some memory laws

Several memory laws have been established for the free recall of word lists. The generality of some of these laws were tested, using tasks which the subjects performed (SPTs) as to-be-recalled list items. SPT recall obeyed one law of word recall in showing a strong positive recency effect in immediate free recall, which appeared to be due to these events being in a temporary state of high accessibility. Differences between word and SPT recall were: 1) The reliable primacy effect associated with word recall did not appear in SPT recall; 2) Subjects reported using active memorisation strategies for word lists, but not for SPT lists; 3) Unlike word recall, diverting the subject's attention to so-called deep or shallow features of the SPTs during presentation did not affect the level of their recall. These results considered together with Cohen & Stewart's (1981) finding that SPT recall was not age-sensitive were taken to indicate that SPTs should be regarded as a different class of memory event than words, and that memory models dealing with SPT recall should de-emphasize the importance of encoding, stressing instead retention, and retrieval operations.     

Effects of word frequency on individual-item and serial order retention: Tests of the order-encoding view

The order-encoding view of the word frequency effect proposes that low-frequency (LF) items attract more attention to the encoding of individual-item information than do high-frequency (HF) items, but at the expense of order encoding (DeLosh & McDaniel, 1996). When combined with the assumption that free recall of unrelated words is organized according to their original order of presentation, this view explains the finding that HF words are better recalled than LF words in pure lists but that, in mixed lists, recall is better for LF words. The present study confirmed that in mixed lists, order memory becomes equivalent for HF and LF words and that the predicted pattern of order memory and recall holds fo r incidental order-encoding conditions, for longerlists than those used inprevious experiments, and for lists with minimal interitem associativity. Moreover, recall from HF lists declined, but recall from LF lists improved, in related-word lists, relative to unrelated-word lists, reversing the usual pure-list free recall advantage for HF words. These results were uniquely predicted by the order-encoding account and favor this view over accessibility, interitem association, and cuing effectiveness explanations of the word frequency effect.     

The influence of acoustic and semantic similarity on long-term memory for word sequences

It has been shown that short-term memory (STM) for word sequences is grossly impaired when acoustically similar words are used, but is relatively unaffected by semantic similarity. This study tests the hypothesis that long-term memory (LTM) will be similarly affected. In Experiment I subjects attempted to learn one of four lists of 10 words. The lists comprised either acoustically or semantically similar words (A and C) or control words of equal frequency (B and D). Lists were learned for four trials, after which subjects spent 20 min. on a task involving immediate memory for digits. They were then asked to recall the word list. The acoustically similar list was learned relatively slowly, but unlike the other three lists showed no forgetting. Experiment II showed that this latter paradox can be explained by assuming the learning score to depend on both LTM and STM, whereas the subsequent retest depends only on LTM. Experiment III repeats Experiment I but attempts to minimize the effects of STM during learning by interposing a task to prevent rehearsal between the presentation and testing of the word sequences. Unlike STM, LTM proved to be impaired by semantic similarity but not by acoustic similarity. It is concluded that STM and LTM employ different coding systems.     

Creating False Memories of Words with or without Recognition of List Items: Evidence for Nonconscious Processes

Subjects exposed to lists of semantically related words falsely remember nonstudied words that are associated with the list items (e.g., Deese, 1959; Roediger & McDermott, 1995). To determine if subjects would demonstrate this false memory effect if they were unable to recognize the list items, we presented lists of semantically related words with or without a concurrent memory load at rates of 2 s, 250 ms, or 20 ms per word (Experiment 1, between-subjects design) and 2 s or 20 ms per word (Experiment 2, within-subjects design). We found that the subjects falsely recognized semantically related nonstudied words in all conditions, even when they were unable to discriminate studied words from unrelated nonstudied words. Recognition of list items was unnecessary for the occurrence of the false memory effect. This finding suggests that this memory illusion can be based on the nonconscious activation of semantic concepts during list presentation.     

Effects of stimulus variability on perception and representation of spoken words in memory

A series of experiments was conducted to investigate the effects of stimulus variability on the memory representations for spoken words. A serial recall task was used to study the effects of changes in speaking rate, talker variability, and overall amplitude on the initial encoding, rehearsal, and recall of lists of spoken words. Interstimulus interval (ISI) was manipulated to determine the time course and nature of processing. The results indicated that at short ISIs, variations in both talker and speaking rate imposed a processing cost that was reflected in poorer serial recall for the primacy portion of word lists. At longer ISIs, however, variation in talker characteristics resulted in improved recall in initial list positions, whereas variation in speaking rate had no effect on recall performance. Amplitude variability had no effect on serial recall across all ISIs. Taken together, these results suggest that encoding of stimulus dimensions such as talker characteristics, speaking rate, and overall amplitude may be the result of distinct perceptual operations. The effects of these sources of stimulus variability in speech are discussed with regard to perceptual saliency, processing demands, and memory representation for spoken words.     

Congruency effects in part-list cuing inhibition.

In demonstrations of part-list cuing inhibition, subjects who are shown a subset of studied list words recall fewer noncue words than subjects not shown such part-list cues. We propose that part-list inhibition is governed in part by an incongruency principle: Inhibition occurs to the extent that part-list cues induce a retrieval framework different from that used to encode list items. In Experiment 1, word lists were studied followed by a test of free recall either without cues, or with cue words serially organized to be either congruent or incongruent with the order of studied items. In Experiments 2-4, cues consisted of every second study item in the original presentation order (congruent ones) or reordered to form famous names or familiar idioms that had been hidden in the study list (incongruent cues). More part-list inhibition was observed with incongruent cues than congruent cues in all 4 experiments.     

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     

Information processing in reading-disabled and nondisabled children

Reading disabled and nondisabled children (13-14 years of age) were presented lists of 10 words each at different rates (one word per 1, 2, and 4 sec), and immediately after the last word of each list they recalled the words in any order. Recall of the first few words presented from each list (the primacy effect) was lower in reading-disabled than nondisabled children, and slower presentation rates increased the primacy effect in both groups. These findings suggest that reading-disabled children are not completely failing to use elaborative encoding but are using less effective elaborative encoding than nondisabled readers. With all presentation rates, recall of the last few words (the recency effect) was comparable in both groups, suggesting that older reading-disabled children encode and recognize the stimuli and that elaborative encoding is deficient in reading-disabled in spite of adequate stimulus encoding and recognition.     

词频、易接近性和词表序列成分对近因效应影响的实验研究

本研究目的探讨词频、易接近性和词表序列成分对近因效应的影响及其原因。两个实验以不同词频和不同易接近性的中文词为材料,运用直接自由回忆程序和操纵词表的组成成分,探讨近因效应的特点。实验结果表明：词频对近因效应的作用受词表序列成分的影响,对于纯的词表,高频词回忆的比例比低频词更高,对于混合词表,低频词回忆的比例比高频词更高,但是词的易接近性不影响近因效应且不受词表序列成分影响。文章最后对近因效应的性质进行了讨论。     

List composition and the word length effect in immediate recall: A comparison of localist and globalist assumptions

Lists of short words usually are recalled better than lists of longer words in immediate recall tasks. Such word length effects might be explained by localist accounts, in which the length of each word in a list affects the recall of that word only, or by globalist accounts, in which the lengths of at least some words affect the recall of other words (e.g., Baddeley, 1986). In a recent localist account, Neath and Nairne (1995) proposed that the recall of each word depends on the likelihood that features within the word are contaminated within the memory representation. We tested this by presenting not only homogeneous lists of short and long words, but also mixed lists, and by including articulatory suppression on some trials. The short-word advantage depended on the composition of the list, ruling out a strictly localist approach. There appear to be several globalist influences on recall, including distinctiveness factors as well as phonological storage and articulation.     

A recency-based account of the list length effect in free recall

Free recall was examined using the overt rehearsal methodology with lists of 10, 20, and 30 words. The standard list length effects were obtained: As list length increased, there was an increase in the number and a decrease in the proportion of words that were recalled. There were significant primacy and recency effects with all list lengths. However, when the data were replotted in terms of when the words were last rehearsed, recall was characterized by extended recency effects, and the data from the different list lengths were superimposed upon one another. These findings support a recency-based account of episodic memory. The list length effect reflects the facts that unrehearsed words are less recent with longer lists, and that with longer lists, a reduced proportion of primacy and middle items may be rehearsed to later positions.     

Word frequency and list composition effects in associative recognition and recall

The effects of list composition and word frequency on cued recall, associative recognition, and item recognition were examined in three experiments For pure-frequency lists, cued recall and associative recognition show better performance on common high-frequency (HF) words than on rare low-frequency (LF) words. Item recognition, however, shows an advantage for LF words. In mixed lists, consisting of half HF and half LF words, the HF advantage in cued recall disappeared; however, the word frequency effects in item and associative recognition were unchanged. These results are inconsistent with explanations based on differential attention or co-rehearsal of KF and LF words. However, the results are consistent with list strength results which show that recognition is insensitive to strength-based list composition, but that recall is sensitive to list composition.