Hazel Emslie

The Children's Test of Nonword Repetition: a test of phonological working memory.

This article presents findings from the Childrens Test of Nonword Repetition (CNRep). Normative data based on its administration to over 600 children aged between four and nine years are reported. Close developmental links are established between CNRep scores and vocabulary, reading, and comprehensive skills in children during the early school years. The links between nonword repetition and language skills are shown to be consistently higher and more specific than those obtained between language skills and another simple verbal task with a significant phonological memory component, auditory digit span. The psychological mechanisms underpinning these distinctive developmental relationships between nonword repetition and language development are considered.

Phonological memory and vocabulary development during the early school years: a longitudinal study

The nature of the developmental association between phonological memory and vocabulary knowledge was explored in a longitudinal study. At each of 4 waves (at ages 4, 5, 6, and 8 yrs), measures of vocabulary, phonological memory, nonverbal intelligence, and reading were taken from 80 children. Comparisons of cross-lagged partial correlations revealed a significant shift in the causal underpinnings of the relationship between phonological memory and vocabulary development before and after 5 yrs of age. Between 4 and 5 yrs, phonological memory skills appeared to exert a direct causal influence on vocabulary acquisition. Subsequently, though, vocabulary knowledge became the major pacemaker in the developmental relationship, with the earlier influence of phonological memory on vocabulary development subsiding to a nonsignificant level. (PsycINFO Database Record (c) 2008 APA, all rights reserved)

Random Generation and the Executive Control of Working Memory

A series of experiments explores the capacity for generating sequences of random responses, relating it to the central executive component of working memory. Experiment 1 shows a broadly similar pattern of redundancy increasing with speed of generation for both the verbal generation of digits and the manual pressing of keys. In both cases deviations from randomness are shown to reflect the increasing use of a limited number of stereotyped response sets. The remaining experiments use keyboard generation. Experiment 2 demonstrates that concurrent immediate serial recall decreases randomness, and that longer recall sequences produce less random output. Experiments 3 and 4 show that whereas simple counting has no effect on randomness, serial recall, semantic category generation, and concurrent digit generation have substantial effects, and a concurrent fluid intelligence test has the greatest influence on the randomness of key pressing. It is suggested that the task of random generation resembles that of category fluency because it requires the subject to switch retrieval plans and inhibit repetition. On this basis it is predicted that a task involving repeated switching of categories will interfere with generation, despite being predictable and having a low memory load. Experiments 5 and 6 confirm this prediction. Strengths and limitations of the switching hypothesis are discussed, as are the implications of our results for the analysis of executive processes.

Reducing everyday memory and planning problems by means of a paging system: a randomised control crossover study

OBJECTIVES To evaluate a paging system designed to improve independence in people with memory problems and executive deficits. METHODS After a successful pilot study, a randomised control trial was conducted involving a crossover design with 143 people aged between 8 and 83 years. All had one or more of the following: memory, planning, attention, or organisation problems. Most had sustained a traumatic head injury or a stroke although a few had developmental learning difficulties or other conditions. The crossover design ensured that some people received a pager after a 2 week baseline whereas others were required to wait for 7 weeks after the baseline before receiving the pager. Participants were assessed at three time periods—namely, at baseline, 7 weeks, and at 14 weeks postbaseline. RESULTS More than 80% of those who completed the 16 week trial were significantly more successful in carrying out everyday activities (such as self care, self medication, and keeping appointments) when using the pager in comparison with the baseline period. For most of these, significant improvement was maintained when they were monitored 7 weeks after returning the pager. CONCLUSIONS This particular paging system significantly reduces everyday failures of memory and planning in people with brain injury.

The influences of number of syllables and wordlikeness on children’s repetition of nonwords

It has recently been suggested that the developmental association between nonword repetition performance and vocabulary knowledge reflects the contribution of phonological memory processes to vocabulary acquisition (e.g., Gathercole & Baddeley, 1989). An alternative account of the association is that the child uses existing vocabulary knowledge to support memory for nonwords. The present article tests between these two alternative accounts by evaluating the role of phonological memory and linguistic factors in nonword repetition. In a longitudinal database, repetition accuracy in 4-, 5-, and 6-year-olds was found to be sensitive to two independent factors: a phonological memory factor, nonword length, and a linguistic factor, wordlikeness. To explain these combined influences, it is suggested that repeating nonwords involves temporary phonological memory storage which may be supported by either a specific lexical analogy or by an appropriate abstract phonological frame generated from structurally similar vocabulary items.

Evaluation of NeuroPage: a new memory aid

This report describes NeuroPage, a simple and portable paging system, developed in California by the engineer father of a son with head injury working together with a neuropsychologist. Using an ABA single case experimental design, the efficacy of NeuroPage was evaluated with 15 neurologically impaired subjects all of whom had significant everyday memory problems because of organic memory impairment or because of problems with planning and organisation consequent on frontal lobe damage. Data were analysed with an odds ratio test which takes into account different underlying success rates for each target and calculates an average improvement factor. This test showed a significant improvement between the baseline and the treatment phases for each subject (P<0.05).

A randomized control trial to evaluate a paging system for people with traumatic brain injury

Although memory problems following acquired brain damage are common, some people are able to compensate for these problems through external aids. It was recently demonstrated that a paging system could reduce the everyday memory and planning problems for people with non-progressive brain injury. The 143 patients who participated in the study comprised several diagnostic groups. This paper reports on the sub-group of people with TBI (n = 63). This sub-group was part of the larger sample of 143 already published in the 2001 study. A randomized control cross-over design randomly allocated people to group A (pager first) or group B (waiting list first). Each participant chose their own tasks for which they needed reminders. During a 2 week baseline, successful task achievement was documented. Group A achieved 47.14% of tasks and group B 47.88%. People in group A then received a pager for 7 weeks. During the last 2 weeks of this 7 week period, task achievement was documented again. Group A now achieved 71.80% of tasks and group B (on the waiting list) achieved 49.05% (no different from baseline). Group A then returned their pagers and group B received pagers. During the last 2 weeks of this stage participants were monitored once more. At this point, people in group A had dropped back slightly but were still statistically significantly better than during the baseline (67.23%). Group B, meanwhile, were now achieving 73.62% of tasks. This was statistically significantly better than baseline and significantly better than group A, now in the post-pager phase. It is concluded that this paging system significantly reduces the everyday memory and planning problems of people with TBI.

Improvement or simply practice? The effects of twenty repeated assessments on people with and without brain injury

Measuring recovery of function may mean testing the same individual many times, a procedure that is inevitably open to improvement due to learning on the specific tests rather than recovery per se. This is particularly likely to be an issue with measures of memory performance. We therefore studied the performance of normal and brain-injured people across 20 successive test sessions on measures of orientation, simple reaction time, forward and backward digit span, visual and verbal recognition, word list learning and forgetting, and on three semantic memory measures, namely, letter and category fluency and speed of semantic processing. Differences in overall performances between the two groups occurred for all tests other than orientation, digit span forward, and simple reaction time, although the tests differed in their degree of sensitivity. The tests varied in the presence or absence of practice effects and in the extent to which these differed between the two groups. Data are presented that should allow investigators to select measures that are likely to optimize sensitivity while minimizing possible confounding due to practice effects.

Text entry on handheld computers by older users

Small pocket computers offer great potential in workplaces where mobility is needed to collect data or access reference information while carrying out tasks such as maintenance or customer support. This paper reports on three studies examining the hypothesis that data entry by older workers is easier when the pocket computer has a physical keyboard, albeit a small one, rather than a touchscreen keyboard. Using a counter-balanced, within-subjects design the accuracy and speed with which adults over 55 years of age could make or modify short text entries was measured for both kinds of pocket computer. The keyboard computer was the Hewlett Packard 360LX (HP), but the touch-screen computers varied across studies (experiment 1: Apple Newton™ and PalmPilot™; experiment 2: Philips Nino™; experiment 3: Casio E10™). All studies showed significant decrements in accuracy and speed when entering text via the touch-screen. Across studies, most participants preferred using the HPs small physical keyboard. Even after additional practice with the touch screen (experiments 2 and 3) many entries still contained errors. Experiment 3 showed that younger people were faster but not more accurate than older people at using the touch-screen keyboard. It is concluded that satisfactory text entry on palm-size computers awaits improvements to the touch-screen keyboard or alternative input methods such as handwriting or voice. Interface developments that assist older people typically benefit younger users too.

Compensatory strategies for acquired disorders of memory and planning: differential effects of a paging system for patients with brain injury of traumatic versus cerebrovascular aetiology

Background: Previous studies have demonstrated the effectiveness of paging systems in compensating for everyday memory and planning problems after brain injury, including in individuals with traumatic brain injury (TBI). Methods: Here, in addition to further analyses of the TBI data from a previous randomised control crossover trial, results are reported from a sub-group of 36 participants with brain injury from cerebrovascular accident (CVA). Results: Results indicate that, as with the TBI group, the pager was effective. However, the pattern of results following cessation of treatment differed. At a group level, TBI participants demonstrated maintenance of pager-related benefits, whereas CVA participants’ performance returned to baseline levels. Comparisons of demographic and neuropsychological characteristics of the groups showed that the CVA group was older, had a shorter interval post-injury, and had poorer executive function than the TBI group. Furthermore, within the TBI group, maintenance was associated with executive functioning, such that executive dysfunction impeded maintenance. This correlation remained after controlling for demographic differences between groups. Conclusions: Together, these findings suggest that executive dysfunction may affect treatment—for example, whether or not temporary use of the pager is sufficient to establish a subsequently self-sustaining routine.