Implications of aging, lexicality, and item length for the mechanisms underlying memory span

Verbal and visual serial-order memory in deaf signers and hearing nonsigners: A systematic review and meta-analysis

Previous research suggests Deaf signers may have different short-term and working memory processes compared with hearing nonsigners due to prolonged auditory deprivation. The direction and magnitude of these reported differences, however, are variable and dependent on memory modality (e.g., visual, verbal), stimulus type, and research design. These discrepancies have made consensus difficult to reach which, in turn, slows progress in areas such as education, medical decision-making, and cognitive sciences. The present systematic review and meta-analysis included 35 studies (N = 1,701 participants) that examined verbal (n = 15), visuospatial (n = 10), or both verbal and visuospatial (n = 10) serial-memory tasks comparing nonimplanted, Deaf signers to hearing nonsigners across the life span. Multivariate meta-analyses indicated a significant, negative effect of deafness on verbal short-term memory (forward recall), g = -1.33, SE = 0.17, p < .001, 95% CI [-1.68, -0.98], and working memory (backward recall), g = -0.66, SE = 0.11, p < .001, 95% CI [-0.89, -0.45], but no significant effect of deafness on visuospatial short-term memory, g = -0.055, SE = 0.17, p = 0.75, 95% CI [-0.39, 0.28]. Visuospatial working memory was not analyzed due to limited power. Population estimates for verbal and visuospatial short-term memory were moderated by age wherein studies with adults demonstrated a stronger hearing advantage than studies with children/adolescents. Quality estimates indicated most studies were of fair quality, with only 38% of studies involving Deaf authors. Findings are discussed in the context of both Deaf equity and models of serial memory.

Destination Memory for Self-Related Information: When I Tell Elvis Presley about My Favorite Food

Destination memory, the ability to remember to whom information was previously delivered, has found to be influenced by social processing and social interactions. This memory has also been shown to be compromised in normal aging. Our paper investigated whether older adults would demonstrate better destination memory for self-related information than for general information.

METHODS

We asked younger adults and older adults to tell self-related information (e.g., "I like Chinese food") and semantic information (e.g., "the moon is smaller than the sun") to pictures of celebrities (e.g., Elvis Presley).

RESULTS

Analysis showed higher destination memory for self-related information than for semantic information in older adults and younger adults.

DISCUSSION

Older adults may draw on self-related information to improve memory and social interactions.

Wakeful Rest Benefits Recall, but Not Recognition, of Incidentally Encoded Memory Stimuli in Younger and Older Adults

Older adults exhibit deficits in episodic memory tasks, which have often been attributed to encoding or retrieval deficits, with little attention to consolidation mechanisms. More recently, researchers have attempted to measure consolidation in the context of a behavioral experiment using the wakeful rest paradigm (i.e., a brief, quiet period of minimal stimulation, which facilitates memory performance, compared to a distractor task). Critically, older adults might not produce this effect, given established age differences in other episodic memory processes and mind-wandering. In three experiments, we directly compared younger and older adults in modified versions of the wakeful rest paradigm. Critically, we utilized incidental encoding procedures (all experiments) and abstract shape stimuli (in Experiment 3) to limit the possibility of retrieval practice or maintenance rehearsal as potential confounding mechanisms in producing the wakeful rest effect. Wakeful rest reliably and equally benefited recall of incidentally encoded words in both younger and older adults. In contrast, wakeful rest had no benefit for standard accuracy measures of recognition performance in verbal stimuli, although there was an effect in response latencies for non-verbal stimuli. Overall, these results suggest that the benefits of wakeful rest on episodic retrieval are preserved across age groups, and hence support age-independence in potential consolidation mechanisms as measured by wakeful rest. Further, these benefits do not appear to be dependent on the intentionality of encoding or variations in distractor task types. Finally, the lack of wakeful rest benefits on recognition performance might be driven by theoretical constraints on the effect or methodological limitations of recognition memory testing in the current paradigm.

Age-related reversal of postural adjustment characteristics during motor imagery

Physical and imagined movements show similar behavioral constraints and neurophysiological activation patterns. An inhibition mechanism is thought to suppress overt movement during motor imagery, but it does not effectively suppress autonomic or postural adjustments. Inhibitory processes and postural stability both deteriorate with age. Thus, older people’s balance is potentially vulnerable to interference from postural adjustments induced by thoughts about past or future actions. Here, young and older adults stood upright and executed or imagined manual reaching movements. Reported arm movement time (MT) of all participants increased with target distance. Older participants reported longer MT than young participants when executing arm movements, but not when imagining them. Older adults’ anteroposterior (AP) and mediolateral (ML) postural sway was higher than young adults’ at baseline, but their AP sway fell below their baseline level during manual imagery. In contrast, young adults’ AP sway increased during imagery relative to their baseline. A similar tendency to reduce sway in the ML direction was also observed in older adults during imagery in a challenging stance. These results suggest that postural response during manual motor imagery reverses direction with age. Motor imagery and action planning are ubiquitous tasks, and older people are likely to spend more time engaged in them. The shift toward restricting body sway during these tasks is akin to a postural threat response, with the potential to interfere with balance during activities of daily living.

Semantic effects in sentence recall: the contribution of immediate vs delayed recall in language assessment

Sentence recall is increasingly used to assess language. It is widely debated what the task is actually testing, but one rarely explored aspect is the contribution of semantics to sentence recall. The few studies that have examined the role of semantics in sentence recall have employed an 'intrusion paradigm', following Potter and Lombardi (1990), and their paradigm relies on interference errors with conclusions based on an analysis of error patterns. We have instead manipulated the semantic plausibility of whole sentences to investigate the effects of semantics on immediate and delayed sentence recall. In Study 1, adults recalled semantically plausible and implausible sentences either immediately or after distracter tasks varying in lexical retrieval demands (backward counting and picture naming). Results revealed significant effects of plausibility, delay, and a significant interaction indicating increasing reliance on semantics as the demands of the distracter tasks increased. Study 2, conducted with 6-year-old children, employed delay conditions that were modified to avoid floor effects (delay with silence and forward counting) and a similar pattern of results emerged. This novel methodology provided robust evidence showing the effectiveness of delayed recall in the assessment of semantics and the effectiveness of immediate recall in the assessment of morphosyntax. The findings from our study clarify the linguistic mechanisms involved in immediate and delayed sentence recall, with implications for the use of recall tasks in language assessment.

LEARNING OUTCOMES

The reader will be able to: (i) define the difference between immediate and delayed sentence recall and different types of distractors, (ii) explain the utility of immediate and delayed recall sentence recall in language assessment, (iii) discuss suitability of delayed recall for the assessment of semantics.

Revisiting backward recall and benchmark memory effects: a reply to Bireta et al. (2010)

When participants are asked to recall lists of items in the reverse order, known as backward recall, several benchmark memory phenomena, such as the word length effect, are abolished (Bireta et al. Memory & Cognition 38:279-291, 2010). Bireta et al. (Memory & Cognition 38:279-291, 2010) suggested that in backward recall, reliance on order retention is increased at the expense of item retention, leading to the abolition of item-based phenomena. In a subsequent study, however, Guérard and Saint-Aubin (in press) showed that four lexical factors known to modulate item retention were unaffected by recall direction. In a series of five experiments, we examined the source of the discrepancy between the two studies. We revisited the effects of phonological similarity, word length, articulatory suppression, and irrelevant speech, using open and closed pools of words in backward and forward recall. The results are unequivocal in showing that none of these effects are influenced by recall direction, suggesting that Bireta et al.'s (Memory & Cognition 38:279-291, 2010) results are the consequence of their particular stimuli.

Differential contribution of cognitive and psychomotor functions to the age-related slowing of speech production

Healthy elderly adults are slower to initiate and produce speech. However, the sources of the slowing remain poorly understood. The present study evaluates to which extent psychomotor and cognitive changes influence age-related slowing in speech generation. Four verbal tasks varying in degree of difficulty and cognitive demands were used to evaluate 30 young and 30 healthy elderly. Speed of word production was measured by reaction times and pronunciation durations. Stroop test and Digits backwards were used as cognitive predictors while the Purdue Pegboard and Finger Tapping were used as psychomotor predictors. The relative contribution of cognitive and psychomotor functioning was evaluated by hierarchical regression analyses and based on the processing speed hypothesis. Results showed that Vocabulary and psychomotor execution significantly explained a portion of the variance in RTs depending on type of verbal task. These variables explained 36% of the total variance in reading, 26% in naming, 31% in phonemic fluency and 47% in semantic fluency. Also, Vocabulary and psychomotor functions strongly predicted pronunciation speed. Conversely, tests related to executive functions and working memory were not significant predictors. These data demonstrate the importance of the interplay between Vocabulary and psychomotor decline on speed of language production among healthy elderly adults.

Lexicality and phonological similarity: A challenge for the retrieval‐based account of serial recall?

The retrieval-based account of serial recall (Saint-Aubin & Poirier, 2000) attributes lexicality, phonological similarity, and articulatory suppression effects to a process where long-term representations are used to reconstruct degraded phonological traces. Two experiments tested this assumption by manipulating these factors in the recall of four- and five-item lists of words and non-words. Lexicality enhanced item recall (IR), but only affected position accuracy (PA) for five-item lists under suppression. Phonological similarity influenced both words and non-words, and produced impaired PA in silent and suppressed conditions. Consistent with the retrieval-based account, words and non-words of high word-likeness appear subject to redintegration. However, some findings, like suppression not reducing the phonological similarity impairment in suppressed conditions, present challenges for the retrieval-based account and other models of serial recall.

Modulating the phonological similarity effect: the contribution of interlist similarity and lexicality

The classical phonological similarity effect (PSE) was studied with words and nonwords in two immediate serial recall (ISR) tasks. The relative contributions of intralist and interlist interference were compared, and differential effects on item and order memory were observed. PSE occurred with words and was reversed with nonwords. In addition, PSE was modulated by interlist similarity, which enhanced recall of rhyme items and impaired recall of distinct items. Finally, interlist similarity reduced item recall of words, whereas it improved serial recall of nonwords. The latter finding rules out the hypothesis that the reverse PSE for nonwords is due to interlist interference. It is concluded that two opposing effects of phonological intralist similarity cause the interaction between PSE and lexicality in ISR. With words, the positive effect on item recall is usually masked by a much more disruptive effect on position accuracy. With nonwords, however, the positive effect often masks the negative one. These findings are discussed in relation to current models of verbal short-term memory.

Semantic similarity and immediate serial recall: is there an effect on all trials?

In immediate serial recall, items are better recalled when they are all drawn from the same semantic category. This is usually accounted for by a two-stage retrieval-based framework, in which, at recall, long-term knowledge is used to reconstruct degraded phonological traces. The category shared by list items would serve as an additional retrieval cue restricting the number of recall candidates. Usually, the long-term search set is not defined, but some authors have suggested an extended search set and others a restricted set that is composed of the most recently presented items. This was tested in an experiment in which participants undertook an immediate serial recall task either alone or under articulatory suppression with either semantically similar or dissimilar lists. A trial-by-trial analysis revealed that, in both quiet and suppression conditions, items from similar lists were better recalled on all the trials, including the first one. In addition, there was no interaction between semantic similarity and trial, indicating that the effect of similarity was of similar size on all the trials. The results are best interpreted within a proposal suggesting an extended long-term search set.

Cognitive ability, expertise, and age differences in following air-traffic control instructions

Differences in cognitive ability and domain-specific expertise may help explain age differences in pilot performance. Pilots heard air-traffic controller messages and then executed them while "flying" in a simulator. Messages varied in length and speech rate. Age was associated with lower accuracy, but the expected Age x Message Difficulty interactions were not obtained. Expertise, as indexed by pilot ratings, was associated with higher accuracy; yet expertise did not reduce age differences in accuracy. The effect of age on communication task accuracy was largely explainable as an age-associated decrease in working memory span, which in turn was explainable as decreases in both speed and interference control. Results are discussed within frameworks of deliberate practice and cognitive mediation of age differences.

Age-related deficits in free recall: the role of rehearsal

Age-related deficits have been consistently observed in free recall. Recent accounts of episodic memory suggest that these deficits could result from differential patterns of rehearsal. In the present study, 20 young and 20 older adults (mean ages 21 and 72 years, respectively) were presented with lists of 20 words for immediate free recall using the overt rehearsal methodology. The young outperformed the older adults at all serial positions. There were significant age-related differences in the patterns of overt rehearsals: Young adults rehearsed a greater number of different words than did older adults, they rehearsed words to more recent serial positions, and their rehearsals were more widely distributed throughout the list. Consistent with a recency-based account of episodic memory, age deficits in free recall are largely attributable to age differences in the recency, frequency, and distribution of rehearsals.

Complexity effects in visuo-spatial working memory: implications for the role of long-term memory

Several studies have shown that the capacity of visuo-spatial working memory is limited by complexity. Using a variant of the Corsi blocks task, this paper investigates the effect of complexity of the to-be-remembered path on visuo-spatial memory span. Redundancy was determined by three Gestalt principles: symmetry, repetition, and continuation. Experiment 1 revealed an effect of path complexity. The subsequent experiments explored whether the superiority for recall of structured over complex paths can be attributed solely to the operation of visuo-spatial working memory, or whether it also reflects the use of long-term knowledge. Experiment 2 demonstrated that the effect of complexity remained, even when the mechanisms for visuo-spatial coding were removed by a secondary visuo-spatial task. In Experiments 3 and 4 subjects were trained in the recall of complex paths. This led to the creation of long-term memory representations for these paths, as shown by an improvement in their span, and a concomitant lack of transfer to new paths. Finally, Experiment 5 showed that one prior repetition of a complex path was sufficient to produce specific and long-term learning effects. These results point to the involvement of long-term memory processes in the temporary retention of visuo-spatial material for which representations exist in long-term memory. They also suggest that the effect of complexity may provide a tractable technique for investigating the mechanisms underlying the limits of visuo-spatial short-term storage.