Phonological recoding under articulatory suppression

We report data from an experiment in which participants performed immediate serial recall of visually presented words with or without articulatory suppression, while also performing homophone or rhyme detection. The separation between homophonous or rhyming pairs in the list was varied. According to the working memory model (Baddeley, 1986; Baddeley & Hitch, 1974), suppression should prevent articulatory recoding. Nevertheless, rhyme and homophone detection was well above chance. However, with suppression, participants showed a greater tendency to false-alarm to orthographically related foils (e.g., GIVE–FIVE). This pattern is similar to that observed in short-term memory patients.     

Evidence for a modality effect in sentence retention

It is well known that an acoustic-sensory code supports retention of linguistic materials whose storage is particularly based on phonological information (e.g., unrelated word lists). The present study investigates whether such a code also contributes to the retention of sentences. It has been shown that short-term sentence recall particularly depends on propositional and lexicosemantic information, which are assumed to be supplied independently of modality influences. We employed the intrusion paradigm of Potter and Lombardi (1990) and manipulated the availability of acoustic-sensory information. Participants were instructed to read sentences either silently or aloud. Since these two reading conditions also differ with respect to articulatory information, a further condition that provided articulatory but not acoustic-sensory information was introduced (i.e., silent mouthing). Our data suggest that acoustic-sensory information is used, if available, even in sentence recall.     

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.     

Does Articulatory Suppression Remove the Irrelevant Speech Effect?

Salamé and Baddeley (1982) reported that the effect of irrelevant speech on the serial recall of visually presented sequences was abolished when subjects performed articulatory suppression during presentation and recall of the target items. They argued that this is because suppression isolates visually presented material from the phonological store, which they consider to be the locus of the irrelevant speech effect. In the present experiment, an alternative interpretation of Salamé and Baddeley's findings was investigated. Salamé and Baddeley used nine-item sequences, and observed very low levels of recall when articulation was suppressed. It is therefore possible that Salamé and Baddeley's failure to observe any additional effect of irrelevant speech reflects either a floor effect or else a strategic choice by subjects to abandon the use of a phonological memory code because of task difficulty. In the experiment reported here, this issue was investigated by using both six- and nine-item sequences. Results revealed no effect of irrelevant speech under articulatory suppression even at the shorter sequence length. The results therefore replicate and extend the findings of Salamé and Baddeley (1982), and provide support for their view that visually presented material must be articulated before it becomes susceptible to interference from irrelevant speech.     

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.     

Item Interference and Time Delays in Working Memory: Immediate Serial Recall

Limitations on immediate recall span have been related by some to temporal limitations of an articulatory rehearsal loop (Baddeley, 1986), and by others to retroactive interference from subsequent items (Lewandowsky & Murdock, 1989; Neath & Nairne, 1995). In the current study, the number of intervening items and retention delays were partially decoupled by varying presentation rate and materials sets. Recently, memory span effects often attributed to temporal limits in rehearsal were shown to be directly related to the output delays during the act of recall (Dosher & Ma, 1998). A functional model of working memory provides a framework within which to evaluate the relative contributions of item interference and retention delays in the accuracy of recall at each serial position. Output delays during recall and interference from items during study were the primary factors in limiting recall, with small additional effects of time delays during study.     

Impairment of the visuo-spatial sketch pad

A case study is presented of a female patient, ELD, who has difficulty in the immediate recall of short sequences of visuo-spatial material following a right-hemisphere aneurysm. Despite poor performance on tasks such as the Brooks Matrix and the Corsi Blocks, ELD is good at the immediate serial recall of letters even when presentation modality is visual and shows effects of phonological similarity and articulatory suppression. This pattern of performance represents a double dissociation from that which has been observed with the short-term memory patient PV (Vallar & Baddeley, 1984), who is extremely poor at serial recall of verbal material but shows no visual memory impairment. It is argued that ELD has an impairment to the visuo-spatial component of working memory (Baddeley, 1986) in the absence of any phonological loop deficit. Further investigation reveals that ELD performs poorly on mental rotation tasks and finds it difficult to use imagery mnemonics, but has no difficulty in retrieving visuo-spatial information from long-term memory so long as it was learnt before her illness.     

Personality,time of day and delayed memory for tv news

An experiment was conducted to test the effects of time of day on delayed memory for televised news stories. Three groups received the same sequence of 6 news stories at 09.30, 13.30 and 16.30, respectively. Unexpected tests of free recall, cued recall and recognition were given about 2 hr after news presentation. Results showed that memory performance improved slightly across the day on tests of recall, and significantly so on recognition. Personality differences were also examined. In general, introverts remembered more than extraverts and differences between them were most marked during the late-afternoon session especially on free recall and when minimal cuing was provided. The results support previous time-of-day findings for delayed retention of complex learning materials. Personality differences observed here are consistent with predicted introvert-extravert differences in memory performance predicted by Eysenck's modified action-decrement hypothesis.     

Conceptual similarity effects on working memory in sentence contexts: Testing a theory of anaphora

The degree of semantic similarity between an anaphoric noun phrase (e.g., the bird) and its antecedent (e.g., a robin) is known to affect the anaphor resolution process, but the mechanisms that underlie this effect are not known. One proposal (Almor, 1999) is that semantic similarity triggers interference effects in working memory and makes two crucial assumptions: First, semantic similarity impairs working memory just as phonological similarity does (e.g., Baddeley, 1992), and, second, this impairment interferes with processes of sentence comprehension. We tested these assumptions in two experiments that compared recall accuracy between phonologically similar, semantically similar, and control words in sentence contexts. Our results do not provide support for Almor's claims: Phonological overlap decreased recall accuracy in sentence contexts, but semantic similarity did not. These results shed doubt on the idea that semantic interference in working memory is an underlying mechanism in anaphor resolution.     

The irrelevant sound effect: What needs modelling, and a tentative model

This paper reviews the literature on the irrelevant sound effect and concludes that, contrary to some claims, the data consistently show that irrelevant sound and articulatory suppression are not functionally equivalent. We evaluate the contribution of Larsen and Baddeley (2003 in this issue) and briefly discuss additional data in support of their position. We perform an error analysis on data from their third experiment and simulate detailed aspects of those data using our primacy model of immediate serial recall. Our model is briefly related to a number of findings in the literature on irrelevant sound.     

Chunk limits and length limits in immediate recall: a reconciliation

Whereas some research on immediate recall of verbal lists has suggested that it is limited by the number of chunks that can be recalled (e.g., N. Cowan, Z. Chen, & J. N. Rouder, 2004; E. Tulving & J. E. Patkau, 1962), other research has suggested that it is limited by the length of the material to be recalled (e.g., A. D. Baddeley, N. Thomson, & M. Buchanan, 1975). The authors investigated this question by teaching new paired associations between words to create 2-word chunks. The results suggest that both chunk capacity limits and length limits come into play. For the free recall of 12-word lists, 6 pre-learned pairs could be recalled about as well as 6 pre-exposed singletons, suggesting a chunk limit. However, for the serially ordered recall of 8-word lists, 4 pre-learned pairs could be recalled about as well as 8 pre-exposed singletons, suggesting a length limit. Other conditions yielded intermediate results suggesting that sometimes both limits may operate together.     

Testing effects for common versus proper names

The present study examines the testing effect as a function of item meaningfulness. In Experiments 1 and 2 participants studied lists of words that could serve as proper names or occupations (e.g., Mr Baker or baker), with the items given in a name context for one group and an occupation context for a second group. During an intervening phase participants restudied some items and were given a cued recall test (Experiment 1) or a free recall test (Experiment 2) on other items. On a final free recall test memory was better for tested items than studied items in both the name and occupation contexts. Experiment 3 followed the same procedure as Experiment 1, except that participants studied lists of proper names that do not have alternative uses in the English language (e.g., Mr Anderson) or studied concrete nouns (e.g., letter). Tested items were better remembered on a final test than studied items, and there was no interaction with type of study material. These results show that the testing effect extends to proper names, material that is commonly assumed to differ from common names on several dimensions.     

Examining the role of working memory resources in following spoken instructions

This study investigated the involvement of working memory (WM) in following spoken instructions using concurrent tasks designed to disrupt components of the Baddeley and Hitch WM model [Baddeley, A. D., & Hitch, G. J. (1974). Working memory. In G. H. Bower (Ed.), The psychology of learning and motivation: Advances in research and theory (Vol. 8, pp. 47–89). New York, NY: Academic Press]. In each of three experiments, participants were presented with sequences of instructions to be either verbally repeated or physically performed using relevant objects. Backward counting, articulatory suppression, and eye closure during instruction encoding all disrupted recall, and also impaired recall of the linkage between movements and objects. Recall of actions was more accurate when they were physically enacted than repeated verbally, an advantage that was not affected by concurrent tasks. These findings indicate that aspects of the recall of spoken instructions including the binding of constituent movements to objects draw on multiple WM resources. The benefits of physical enactment of the instructed sequence do not appear to depend on the components of WM investigated in these studies.     

Semantic processing can facilitate free recall in mildly retarded adolescents

The efficacy of semantic processing in free recall was investigated in two experiments with EMR adolescents. In Experiment 1, they were taught to use one of two semantic strategies for memorizing a 15-word list. Compared with controls, neither strategy helped recall either in original learning or transfer. In Experiment 2, one of the semantic strategies, a story mnemonic, was investigated further. Rather than being taught to construct their own stories as in Experiment 1, subjects in Experiment 2 were provided with experimenter-composed stories. They showed better immediate recall and retention after 2 months than did no-strategy controls. However, about 1 year after original learning, the retention of experimental and control subjects no longer differed. Discussion focused on the story mnemonic's potential utility and the criteria for judging such potential, e.g., amount of facilitation, ease of training and performance of the strategy, and the degree of its generalizability.     

Attempted clinical application of a technique for promoting robust free recall to a case of alcoholic Korsakoff's syndrome

A case study is reported which attempted to teach personal orienting information (i.e., recent history) to an amnesic male patient. The structured cuing methods reported by Kovner, Mattis, and Pass (1985, Journal of Clinical and Experimental Neuropsychology, 7, 395-411) were adopted. This involves structured presentation and cuing of target words embedded in a narrative. Some patients eventually are able to freely recall large amounts of material presented in this way. In the present case, the patient received 30 training sessions over 8 weeks. The material to be remembered was 10 target words pertaining to recent personal history. These words were embedded in accompanying storyline. The patient's immediate recall at the end of each session improved to some extent over the training period. However, delayed recall for the material remained nil throughout. Twelve months after the last training session the patient showed some "implicit" retention of the material. The findings are contrasted with Kovner et al.'s dramatic results and discussed.     

Memory for non-native language: The role of lexical processing in the retention of surface form

Research on memory for native language (L1) has consistently shown that retention of surface form is inferior to that of gist (e.g., Sachs, 1967). This paper investigates whether the same pattern is found in memory for non-native language (L2). We apply a model of bilingual word processing to more complex linguistic structures and predict that memory for L2 sentences ought to contain more surface information than L1 sentences. Native and non-native speakers of English were tested on a set of sentence pairs with different surface forms but the same meaning (e.g., “The bullet hit/struck the bull's eye”). Memory for these sentences was assessed with a cued recall procedure. Responses showed that native and non-native speakers did not differ in the accuracy of gist-based recall but that non-native speakers outperformed native speakers in the retention of surface form. The results suggest that L2 processing involves more intensive encoding of lexical level information than L1 processing.     

Boundary extension: Findings and theories

A view of a scene is often remembered as containing information that might have been present just beyond the actual boundaries of that view, and this is referred to as boundary extension. Characteristics of the view (e.g., scene or nonscene; close-up or wide-angle; whether objects are cropped, static, or in motion, emotionally neutral or emotionally charged), display (e.g., aperture shape and size; target duration; retention interval; whether probes of memory involve magnification/minification or change in physical distance), and observer (e.g., allocation of attention; age; planned fixation, gaze direction, and eye movements; monocular or binocular viewing; prior exposure; neurological correlates) that influence boundary extension are reviewed. Proposed mechanisms of boundary extension (perceptual, memory, or motion schema; extension–normalization; attentional selection; errors in source monitoring) are discussed, and possible relationships of boundary extension to other cognitive processes (e.g., representational momentum; remembered distance and remembered size; amodal completion; transsaccadic memory) are briefly addressed.     

The role of articulation in the parsing and retention of letter strings in tachistoscopic free recall

In Mewhort and Campbell's (1981) model of visual word recognition, a scan-parse mechanism transfer information from a character buffer to a short-term store and is largely responsible for the familiarity effects observed in tachistoscopic free recall. Although Mewhort and Campbell do not elaborate on the role of articulation in this task, they do suggest that the scan-parse mechanism acts prior to any involvement of articulatory processes (see Mewhort & Campbell, 1980). However, proponents of working memory (see Baddeley, 1986) are clear that articulation is necessary for the transfer of visual information to a phonological short-term store. In order to clarify the role of articulation in the parsing and retention of letter string, we asked subjects to undertake a tachistoscopic free-recall task, involving first- and fourth-order letter strings, with and without articulatory suppression and/or unattended speech. Unattended speech was observed to interfere with recall, but only when subjects were free to articulate the strings. This implies that subjects were retrieving information from the phonological store and that articulation is necessary for the registration of visual information in this store. The lack of interaction between order-of-approximation and suppression supports the view that the scan-parse mechanism acts independently of articulation. It appears, therefore, that letter strings are parsed at a stage preceding their transfer of the pharmacological store. Finally, the results indicate that subjects are able to draw directly on a representation of the parsed components of a letter string and may do so when phonological storage is difficult.(ABSTRACT TRUNCATED AT 250 WORDS)     

Remembering Words Never Presented: False Memory Effects in Dementia of the Alzheimer Type

Thirty-five young adults, 35 older adults and 29 individuals with dementia of the Alzheimer’s type studied lists of semantically related words (e.g., thread, pin, sewing) that converged on a non-presented lure (needle). Compared to the young adults, older adults remembered (recall and recognition tests) fewer studied items but falsely remembered more non-presented lures. Memory for studied items was lower in the DAT group compared to normal elders. The DAT group did recall some non-presented lures, although unlike the older adults, recall of non-presented lures was not elevated compared to veridical memory. Similar to the normal elders, the DAT group showed increased susceptibility to false recognition of non-presented lures. Susceptibility to false recognition did not vary as a function of disease severity.