Free recall measures of short-term store: Are rehearsal and order of recall data necessary?

Several investigators have claimed that immediate free recall is a composite of output from two different storage systems—a short-term store (STS) and a long-term store (LTS). Free recall data and measures of STS were evaluated by having subjects report their rehearsals while lists of words were presented at a rate of one word every 1.25, 2.50, or 5.00 sec. The results support the conclusions that (a) arranging recall as a function of where an item was presented, rather than where it was rehearsed, is inappropriate to discussions of STS and LTS, and (b) computing measures of STS without both rehearsal and order of recall data yields a biased estimate of STS.

     

Time estimation as a function of recall: a test of Ornstein's theory of temporal judgement

The storage size metaphor used by Ornstein to explain subjective estimations of the length of time a task had lasted is contrasted with a recall hypothesis on the basis of the distinction between accessibility and availability. The different hypotheses were tested using a design similar to one which measured recall and recognition of common and uncommon words. Results showed that although an equivalent number of words were still in store for both groups, subjects who had learnt common words showed better recall and judged the learning task to have lasted longer. The results are interpreted as being in favour of the recall hypothesis. A preliminary study showed higher recall and longer time estimations for subjects who had performed a semantic orienting task in a levels-of-processing experiment.     

The effects of social pressure on group recall

In two experiments, individual subjects worked in conjunction with two perceived group members to recall six 30-item categorized word lists. The perceived group members' recall levels were manipulated to establish either high or low group standards. After participating in the perceived group, subjects completed a surprise final individual recall test that covered all of the presented material. On the basis of the hypothesis that the subjects' performance would be affected by social pressure, it was predicted that subjects working in high-performing groups would recall more words than subjects working in low-performing groups on both the group recall tests and the final individual recall test. These predicted results were observed. Thus, a complete analysis of the group recall environment should include a consideration of conformity theory whereby subjects' memories can be affected by their group members' output levels.     

The short-term storage as a buffer memory between long-term storage and the motor system: A simultaneous-processing model

It is assumed that in a free-recall task the short-term store serves as a memory buffer between the long-term store and a final motor stage of word production. Because of this the retrieval process in long-term store is not hindered by the final motor stage of word production since continued output from the long-term store queues in the buffer for motoric processing. Otherwise a time consuming communication between the two processes would be necessary. A stochastic model of this conceptualization is provided to predict the temporal course of free recall as well as a paradigm in which the contribution of the short-term store in free recall can be studied. The experimental results from this paradigm were used to test the model and to estimate short-term storage capacity on the basis of the time course of free recall. The model predictions were in good agreement with the data and the capacity estimate coincides well with estimates found by totally different methods reported in the literature.     

Age-related differences in immediate serial recall: Dissociating chunk formation and capacity

We assessed the contribution of two hypothesized mechanisms to impaired memory performance of older adults in an immediate serial recall task: decreased temporary information storage in a capacity-limited mechanism, such as the focus of attention, and a deficit in binding together different components into cohesive chunks. Using a method in which paired associations between words were taught at varying levels to allow an identification of multiword chunks (Cowan, Chen, & Rouder, 2004), we found that older adults recalled considerably fewer chunks and, on average, smaller chunks than did young adults. Their performance was fairly well simulated by dividing attention in younger adults, unlike what has been found for long-term associative learning. Paired-associate knowledge may be used in an implicit manner in serial recall, given that younger adults under divided attention and older adults use it well despite the relatively small chunk capacities displayed by these groups.     

Effects of signability and imagery on word recall of deaf and hearing students

This study examined 40 deaf and 20 hearing students' free recall of visually presented words varied systematically with respect to signability (i.e., words that could be expressed by a single sign) and visual imagery. Half of the deaf subjects had deaf parents, while the other half had hearing parents. For deaf students, recall was better for words that had sign-language equivalents and high-imagery values. For the hearing students, recall was better for words with high-imagery values, but there was no effect of signability. Over-all, the hearing students recalled significantly more words than the deaf students in both immediate and delayed free-recall conditions. In immediate recall, deaf students with deaf parents reported using a sign-language coding strategy more frequently and recalled more words correctly than deaf students with hearing parents. Serial-position curves indicated several differences in patterns of recall among the groups. These results underline the importance of sign language in the memory and recall of deaf persons.     

Phonological short-term store and the nature of the recency effect: Evidence from neuropsychology

The recency effect in immediate recall of lists of unrelated words was investigated in P.V., a left hemisphere-damaged patient, who had a grossly reduced auditory verbal span, attributed to a selective impairment of a phonological short-term store. No recency effect was evident in free recall of auditorily presented material. When the patient was instructed to recall the final items of the list first, the recency performance remained defective, even though P.V. was able to adopt a recall from end order. In the case of visual presentation, P.V.'s free recall performance was within the normal range and a clear recency occurred in the recall from end condition. These results are consistent with the view that the standard recency effect in immediate free recall of auditorily presented material represents the output of a phonological short-term store to which ordinal retrieval strategies, in P.V.'s case unimpaired, are applied. Finally, the contributions of the phonological short-term store and the process of rehearsal to the recency effect and to immediate memory span performance are discussed.     

Free recall of concrete and abstract words in poor and normal readers

The present study compared poor and normal readers in second and sixth grade on free recall of concrete and abstract words. On the basis of the assumption that memory for abstract words relies more heavily upon linguistic coding ability than does memory for concrete words, it was expected that poor readers would have much greater difficulty on recall of abstract words than would normal readers, but would more closely approximate the normal readers on recall of concrete words. The hypothesis was confirmed at the second-grade level but not at the sixth-grade level, wherein the magnitude of group differences on concrete words was comparable to that on abstract words. Post hoc analyses of intrusion errors suggested that the linguistic coding hypothesis may be a viable explanation of reader group differences on memory tasks only at lower age levels.     

Memory in educable mentally retarded adults: Deficit in subject or experimenter?

Educable mentally retarded (EMR) and nonretarded adults free recalled lists of (a) words, (b) minitasks performed by the subjects (SPTs), (c) minitasks performed by the experimenter (EPTs), or (d) task instructions. The EMR subjects were significantly inferior to the nonretarded subjects in the immediate recall of words, EPTs and instructions, but not in the immediate recall of SPTs. This proficiency of the EMR subjects in SPT recall was attributed to the nonstrategic nature of this test. The EMR subjects were, however, inferior to the nonretarded subjects in a final free recall (recall of all lists) of all four types of item.     

Hearing loss and perceptual effort: Downstream effects on older adults' memory for speech

A group of older adults with good hearing and a group with mild-to-moderate hearing loss were tested for recall of the final three words heard in a running memory task. Near perfect recall of the final words of the three-word sets by both good- and poor-hearing participants allowed the inference that all three words had been correctly identified. Nevertheless, the poor-hearing group recalled significantly fewer of the nonfinal words than did the better hearing group. This was true even though both groups were matched for age, education, and verbal ability. Results were taken as support for an effortfulness hypothesis: the notion that the extra effort that a hearing-impaired listener must expend to achieve perceptual success comes at the cost of processing resources that might otherwise be available for encoding the speech content in memory.     

Redintegration and the benefits of long-term knowledge in verbal short-term memory: an evaluation of Schweickert's (1993) multinomial processing tree model

The impact of four long-term knowledge variables on serial recall accuracy was investigated. Serial recall was tested for high and low frequency words and high and low phonotactic frequency nonwords in 2 groups: monolingual English speakers and French-English bilinguals. For both groups the recall advantage for words over nonwords reflected more fully correct recalls with fewer recall attempts that consisted of fragments of the target memory items (one or two of the three target phonemes recalled correctly); completely incorrect recalls were equivalent for the 2 list types. However, word frequency (for both groups), nonword phonotactic frequency (for the monolingual group), and language familiarity all influenced the proportions of completely incorrect recalls that were made. These results are not consistent with the view that long-term knowledge influences on immediate recall accuracy can be exclusively attributed to a redintegration process of the type specified in multinomial processing tree model of immediate recall. The finding of a differential influence on completely incorrect recalls of these four long-term knowledge variables suggests instead that the beneficial effects of long-term knowledge on short-term recall accuracy are mediated by more than one mechanism.     

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.     

Estimating the Capacity of Phonological Short-term Memory

Two methods of assessing the capacity of phonological short-term memory that minimize support from long-term memory were compared in a sample of 7- and 8-year-old children. The children were tested on immediate serial recall of words and nonwords, and on the serial recognition of sequences composed of words and nonwords. Serial recognition scores were found to be highly related to children's accuracy of recall of nonwords composed of low-probability phonotactic combinations, but were independent of the long-term memory contributions to recall estimated in the serial recall experiment. Children with high vocabulary knowledge performed significantly better than low vocabulary children on both the recall and recognition measures. It is argued that the convergence of the two techniques lends substantial validity to their use as assessments of phonological storage capacity relatively free of long-term memory influence, and that the crucial difference between children varying in vocabulary knowledge lies in this storage capacity rather than the differential availability and use of long-term knowledge.     

Effects of concreteness and semantic relatedness on composite imagery ratings and cued recall

Day and Bellezza (1983) rejected a dual coding imagery explanation for the superior recall of concrete words because unrelated concrete pairs were rated lower in composite imagery but were still remembered better than related abstract pairs. We show that dual coding theory explains their results and our new findings using the same paradigm. In Experiment 1, 120 subjects rated imagery or relatedness for 108 pairs that varied in concreteness, pair relatedness, and associative strength. Incidental cued recall followed. Relatedness and strength affected imagery ratings, as did concreteness, and very low relatedness partly accounted for the low composite imagery ratings for unrelated concrete pairs. Concreteness and relatedness also affected recall, and suporior recall for unrelated concrete pairs occurred consistently under imagery but not under relatedness instructions. In Experiment 2, 40 subjects rated imagery value and recalled 24 pairs. Subsequent questioning indicated that composite images were retrieved better given stimuli from unrelated concrete than from related abstract pairs. These findings and Day and Bellezza’s original results are explained in terms of (1) imaginal and verbal associative processes, which jointly influence composite imagery ratings and recall, and (2) the critical role of stimulus concreteness during image retrieval and recall (i.e., the conceptual peg hypothesis).     

Right-ear advantage and delayed recall

Two studies were performed using monaural presentation of verbal material to test for a right-ear advantage (REA) in recall. It was hypothesized that a delayed recall task and examination of the serial position curve would be a more sensitive test for ear asymmetries than those used in previous studies. In Experiment 1, 30 right-handed male subjects were given lists of words to recall, presented to either the left or right ear, with language chatter, baroque music, or no stimulus concurrently presented to the opposite ear. Both immediate and delayed recall were assessed. The results indicated that the strongest REAs appeared in delayed recall. Moreover, the REAs occurred regardless of the stimulus conditions co-occurring in the other ear. Experiment 2 was done to test whether the REAs in the delayed recall were due to rehearsal biases. Twenty-four right-handed male subjects recalled lists of words with standard instructions and instructions to recall in the reverse order of input (limiting rehearsal). The results indicated that the backward instructions limited and controlled rehearsal and, hence, input to long-term storage; the REAs occurred in delayed recall under all instructional conditions.     

Short-term recall by deaf signers of American Sign Language: implications of encoding strategy for order recall

Two experiments were conducted on short-term recall of printed English words by deaf signers of American Sign Language (ASL). Compared with hearing subjects, deaf subjects recalled significantly fewer words when ordered recall of words was required, but not when free recall was required. Deaf subjects tended to use a speech-based code in probed recall for order, and the greater the reliance on a speech-based code, the more accurate the recall. These results are consistent with the hypothesis that a speech-based code facilitates the retention of order information.     

Instantiation of general terms in young and older adults

Instantiation of general terms in discourse requires inference from general world knowledge and use of linguistic context to particularize meaning. According to the semantic deficit hypothesis, older adults should be less likely than young adults to generate or to store such inferences. In Experiments 1 and 2 an indirect measure, relatedness judgment, was used to assess immediate comprehension and memory for inferences. In Experiment 3 a direct measure, cued recall, was used to tap memory for inferences. No age differences in immediate or delayed memory were observed in Experiments 1 or 2. In Experiment 3 older adults recalled fewer sentences, but there was no evidence for a specific decrement in storage of inferential material. Older adults are not impaired in ability to draw inferences based on general world knowledge, nor are they more likely than young adults to encode linguistic information in a general, stereotypic fashion.     

Word frequency effects in immediate serial recall of pure and mixed lists: tests of the associative link hypothesis.

In immediate serial recall, high-frequency words are better recalled than low-frequency words. Recently, it has been suggested that high-frequency words are better recalled because of their better long-term associative links, and not because of the intrinsic properties of their long-term representations. In the experiment reported here, recall performance was compared for pure lists of high- and low-frequency words, and for mixed lists composed of either one low- and five high-frequency words or the reverse. The usual advantage of high-frequency words was found with pure lists and this advantage was reduced, but still significant with mixed lists composed of five low-frequency words. However, the low-frequency word included in a high-frequency list was recalled just as well as high-frequency words. Results are challenging for the associative link hypothesis and are best interpreted within an item-based reconstruction hypothesis, along with a distinctiveness account.     

Production deficiencies in free recall: A comparison of hyperactive,learning-disabled,and normal children

Free recall of weakly categorizable words was compared in hyperactive (ADDH), reading-disabled, and normal boys. During a baseline trial, hyperactive boys recalled fewer words and showed less category organization than both reading-disabled and normal boys. Following a manipulation designed to encourage semantic encoding of words, hyperactive boys showed an immediate improvement in item recall and organization so that their free-recall performance was similar to that of reading-disabled and normal children. During later trials of a multiple-trial format, hyperactive boys recalled fewer words than did the reading-disabled and normal boys, despite maintaining equality in category organization. Rather than lacking the skill to use semantic organization as a strategy in free recall, hyperactive boys had difficulty in spontaneously generating the organizational strategy in response to instructions to remember and sustaining sufficient effort to task completion.