Decline in working memory updating through ageing: intrusion error analyses

The present research examines the decline in working memory updating through age. Two experiments compared groups of participants in different age ranges (young-old, 55-65 years, old, 66-75 years and old-old, more than 75 years and, in Experiment 2 only, young, 20-30 years). Memory updating tasks were administered, which required participants to remember the smallest items in each list. To perform the task correctly, participants had to update information efficiently, reducing interference from items no longer relevant. Intrusion errors were computed and in the first experiment these were described as "intrusions of irrelevant items" (immediate exclusion) and "intrusions of once relevant items" (delayed exclusion). The oldest adults performed worse in memory updating and made a greater number of intrusion errors of once relevant information. In the second experiment results showed that increases in memory load (number of items that had to be remembered) and updating demand (number of potentially relevant items) impaired performance. The oldest adults had greater difficulty when the task demand was increased. Furthermore, they produced a higher number of intrusion errors, particularly when the updating demand was increased. It therefore appears that elderly people have specific difficulty in updating information in working memory by excluding irrelevant information.     

Age differences in verbal and visuo-spatial working memory updating: evidence from analysis of serial position curves

Memory updating is the ability to select and update relevant information and suppress no-longer-relevant data. The few studies in this area, targeting mainly the verbal domain, have investigated and confirmed an age-related decline in working memory updating ability (De Beni & Palladino, 2004; Van der Linden, Bredart, & Beerten, 1994). The present research examines the ability of younger and older adults to update information in verbal and visuo-spatial running memory tasks. Results showed that the participants' performance was higher in the verbal than in the visuo-spatial task. Nonetheless, independently of the task domain, an age-related decline in updating performance was found. Moreover, analysis of serial positions suggested that, in the updating procedure, the participants were not attempting to actively maintain items, preferring to adopt a low-effort, "recency-based" strategy. The use of this type of strategy is more evident in older participants, as shown in both the accuracy performance and the proportion of intrusion errors.     

Visuospatial working memory and mental representation of spatial descriptions

The purpose of the present research is to investigate whether different components of working memory (WM) are involved in processing spatial and nonspatial texts. The interference effects of two concurrent tasks on comprehension and recall of two kinds of text were investigated in two experiments. Each participant listened to a spatial and a nonspatial text, with one of two concurrent tasks: articulatory suppression or spatial tapping. The dependent variables in Experiment 1 were accuracy of recall and verification of information inferred from the texts. In Experiment 2 response times in the verification task were also considered. Results support the hypothesis that verbal and spatial components of working memory are differentially involved in the comprehension and memory of spatial and nonspatial texts, with a selective interference effect of the spatial concurrent task on the spatial text and an interference effect of the verbal concurrent task on both the spatial and nonspatial texts. These effects emerged for recall, sentence verification, and response times. Our findings confirm previous results showing that the verbal component of working memory is involved in the process of text comprehension and memory. In addition, they show that visuospatial working memory is involved, in so far as the text conveys visuospatial information.     

The effects of imagery instructions on total congenital blind recall

Abstract

Research on the performance of total congenital blind subjects in imagery tasks is of particular interest because it helps to evaluate the consequences of their lack of visual experience. The present paper examines some points which remained unclear in the preceding research on the effects of imagery instructions on the recall of blind subjects. In Experiment 1 it is shown that, in a free recall task of unrelated nouns, the blind may take advantage of imagery instructions, independently of the particular requirement to form either common or bizarre images. In Experiment 2 the multiple image processing deficit of the blind found by De Beni and Cornoldi (1988) was again observed, but the effect was not found when the same quantity of material had to be processed verbally. Results are interpreted as showing that, although the blind may follow imagery instructions, their visual handicap creates specific difficulties in creating interactive images involving several items at the same time.     

What people believe about memory

Two representative samples of adult Norwegians (n=2000) were asked a set of general and specific questions regarding their beliefs and opinions about human memory. The results indicate that on many questions, such as time of the earliest memories, inhibiting effects of collaboration, and memory for dramatic versus ordinary events, the views of the general public concurred with current research findings, and people in general had realistic views about their own memory performance. On other questions, such as the reliability of olfactory as compared with visual and auditory memory, the memory of small children in comparison with that of adults, the likelihood of repression of adult traumatic memories, and on more general questions such as the possibility of training memory and the capacity limitations of long-term memory, a large proportion of the participants expressed views that are less supported by scientific evidence. Implications of these findings are briefly discussed.     

Imagery and rehearsal as study strategies for written or orally presented passages

In the present research, we studied the influence of text presentation modality on recall under imagery, rehearsal, and no strategy instructions. It was hypothesized that imagery is a more effective recall strategy for an oral presentation and rehearsal for a written presentation, and that imagery and rehearsal are effective study strategies. One hundred twenty participants participated, 80 of whom were trained in the use of imagery or rehearsal in the study of passages and 40 of whom made up the control group. A text was presented orally or in writing; the trained participants were to memorize it using the strategy taught, and the participants in the control group were to memorize it using a freely chosen strategy. They were then asked for free written recall. The results confirmed that the participants using imagery recalled the oral presentation better than the written one, and those using rehearsal recalled the written presentation better than the oral one. The discussion focuses on a selective-interference explanation of the presentation modality effects. Practical suggestions are given, and implications for future research are discussed.