Working memory and literacy as predictors of performance on algebraic word problems

Previous studies on individual differences in mathematical abilities have shown that working memory contributes to early arithmetic performance. In this study, we extended the investigation to algebraic word problem solving. A total of 151 10-year-olds were administered algebraic word problems and measures of working memory, intelligence quotient (IQ), and reading ability. Regression results were consistent with findings from the arithmetic literature showing that a literacy composite measure provided greater contribution than did executive function capacity. However, a series of path analyses showed that the overall contribution of executive function was comparable to that of literacy; the effect of executive function was mediated by that of literacy. Both the phonological loop and the visual spatial sketchpad failed to contribute directly; they contributed only indirectly by way of literacy and performance IQ, respectively.     

Interruption-similarity effects during discourse processing

We examined the effect of interruption on reading to determine if discourse processing is susceptible to similarity-based interference. Participants read pairs of passages, either one before the other (in the continuous condition) or with the sentences of the two passages interleaved (in the interruption condition). In addition, the similarity of the types of passages (narrative or expository) in a pair was manipulated. Performance was measured with self-paced reading time of the sentences and with accuracy in answering comprehension questions. In two experiments, interruption slowed the reading of text sentences; this effect of interruption was greatest when the interrupting text was of the same style as the primary text (an interruption-similarity effect). We discuss these results with respect to current models of the role of working memory in discourse processing.     

A comparison of health behaviours in lonely and non-lonely populations

Loneliness can be defined as perceived social isolation and appears to be a relatively common experience in adults. It carries a significant health risk and has been associated with heart disease, depression and poor recovery after coronary heart surgery. The mechanisms that link loneliness and morbidity are unclear but one of the mechanisms may be through poor health beliefs and behaviours. The aims of this cross-sectional survey of 1289 adults were to investigate differences in health behaviours (smoking, overweight, BMI, sedentary, attitudes towards physical activity) in lonely and non-lonely groups. Lonely individuals were more likely to be smokers and more likely to be overweight - obese. The lonely group had higher body mass index scores controlling for age, annual income, gender, employment and marital status. Logistic regression revealed no differences in sedentary lifestyles. Lonely individuals were significantly less likely to believe it was desirable for them to lose weight by walking for recreation, leisure or transportation. The findings provide support for an association between health behaviours, loneliness and excess morbidity reported in previous studies.     

Basis of recency and frequency judgements of novel faces: generalised strength or episode-specific memories?

Evidence for generalised and episode-specific strength in judgements of recency and frequency of novel faces was investigated in two experiments. Novel faces (created using an identikit program) were presented either once or three times in either of two study sets, separated by a 4 minute (Experiment 1) or 24 hour (Experiment 2) delay. In Experiment 2, the study-test phases were preceded by a familiarisation phase in which faces were presented either with or without an occupational label (some faces were not familiarised). In both experiments, judgements of recency were consistent with greater reliance on generalised strength (an amalgamation of recency and frequency of presentation), although there was some evidence for a contribution of episode-specific information. Familiarisation had opposite effects on judgements of recency and frequency, with familiarised faces judged as having been studied more frequently (three times), but less recently (yesterday) than unfamiliarised faces. The latter result is consistent with participants discounting generalised strength when episode-specific information is inadequate.     

Experimental manipulation of prior experience: Effects on item and associative recognition

Frequency of exposure to very low- and high-frequency words was manipulated in a three-phase (familiarisation, study, and test) design. During familiarisation, words were presented with their definition (once, four times, or not presented). One week (Experiment 1) or one day (Experiment 2) later, participants studied a list of homogeneous pairs (i.e., pair members were matched on background and familiarisation frequency). Item and associative recognition of high- and very low-frequency words presented in intact, rearranged, old-new, or new-new pairs were tested in Experiment 1. Associative recognition of very low-frequency words was tested in Experiment 2. Results showed that prior familiarisation improved associative recognition of very low-frequency pairs, but had no effect on high-frequency pairs. The role of meaning in the formation of item-to-item and item-to-context associations and the implications for current models of memory are discussed.