Assessment of retrieval strategy in incidental, intentional, and inclusion tests with word-fragment cues

The purpose of this study was to assess retrieval strategy in incidental, intentional, and inclusion tests with word-fragment cues following a levels-of-processing manipulation at study. The results of Exp. 1 showed small levels-of-processing effects in incidental tests, and most subjects reported involuntary rather than voluntary retrieval of study-list words. In an intentional test, although levels of processing had a much greater effect, quite a few subjects also reported involuntary rather than voluntary retrieval of study-list words, and these subjects showed a smaller effect of levels of processing than subjects reporting voluntary retrieval. These results suggest that subjects given instructions for both voluntary and involuntary retrieval of study-list words in an inclusion test might not in fact attempt voluntary retrieval at all, but simply adopt an involuntary retrieval strategy. The results of Exp. 2 provided evidence to support this suggestion. The general implication is that where test contamination refers to subjects' failure to use retrieval strategies in accordance with test instructions, inclusion tests can be contaminated, as well as incidental or intentional tests, and that it is always necessary to obtain converging evidence about the actual strategies subjects use.     

The role of task persistence in young adolescence for successful educational and occupational attainment in middle adulthood

The main purpose of the present study was to investigate the importance of task persistence in young adolescence for successful educational and occupational attainment in middle adulthood. Data from age 13 (N = 1,092) and adult age (age 43 for women, N = 569 and age 47 for men, N = 393) were taken from the Swedish longitudinal research program entitled "Individual Development and Adaptation." In line with previous research, task persistence was found to be related to changes in grades between age 13 and age 16, over and above other childhood factors. Task persistence at age 13 was also a significant predictor of both income and occupational level in middle adulthood for the men, controlling for a number of childhood factors (including intelligence), and even when educational attainment in adulthood was taken into account. Finally, task persistence was related to educational attainment in adulthood. The authors suggest that task persistence is a second fundamental factor besides general mental ability, influencing attainment within the area of working life and education. The influence of task persistence is discussed in form of personality-environment selection mechanisms.     

Imaging Episodic Memory: Implications for Cognitive Theories and Phenomena

Functional neuroimaging studies are beginning to identify neuroanatomical correlates of various cognitive functions. This paper presents results relevant to several theories and phenomena of episodic memory, including component processes of episodic retrieval, encoding specificity, inhibition, item versus source memory, encoding-retrieval overlap, and the picture-superiority effect. Overall, by revealing specific activation patterns, the results provide support for existing theoretical views and they add some unique information which may be important to consider in future attempts to develop cognitive theories of episodic memory.     

Selective sex differences in declarative memory

Sex invariance of a six-factor, higher order model of declarative memory (two second-order factors: episodic and semantic memory; and four first-order factors: recall, recognition, fluency, and knowledge) was established for 1,796 participants (35-85 years). Metric invariance of first- and second-order factor loadings across sex was demonstrated. At the second-order level, a female advantage was observed for both episodic and semantic memory. At the first-order level, sex differences in episodic memory were apparent for both recall and recognition, whereas the differences in semantic memory were driven by a female superiority in fluency. Additional tests of sex differences in three age groups (35-50, 55-65, and 70-85 years of age) indicated that the female superiority in declarative memory diminished with advancing age. The factor-specific sex differences are discussed in relation to sex differences in hippocampal function.     

Stability, growth, and decline in adult life span development of declarative memory: cross-sectional and longitudinal data from a population-based study

Five-year changes in episodic and semantic memory were examined in a sample of 829 participants (35-80 years). A cohort-matched sample (N=967) was assessed to control for practice effects. For episodic memory, cross-sectional analyses indicated gradual age-related decrements, whereas the longitudinal data revealed no decrements before age 60, even when practice effects were adjusted for. Longitudinally, semantic memory showed minor increments until age 55, with smaller decrements in old age as compared with episodic memory. Cohort differences in educational attainment appear to account for the discrepancies between cross-sectional and longitudinal data. Collectively, the results show that age trajectories for episodic and semantic memory differ and underscore the need to control for cohort and retest effects in cross-sectional and longitudinal studies, respectively.     

An fMRI study of phonological and spatial working memory using identical stimuli

The aim of the present fMRI study was to localize brain areas that were uniquely activated for phonological versus spatial working memory. Previous studies have reported inconsistent results, most likely because of methodological heterogeneity varying both stimuli and instructions in the same study. Here, identical consonant-vowel-consonant non-words were visually presented to the subjects in a 2-back paradigm under two different instructions; the subjects either had to memorize the non-words per se or their location. The results give evidence for a hemispheric organization of working memory, with dominance for processing of phonological information in the left hemisphere and frontal cortex, and spatial information in the right hemisphere and parietal cortex. The results also reflect a certain overlap between the neuronal network for working memory and processing of verbal and spatial material. These findings are discussed with regard to processing specificity and the extent that activated areas also may reflect perceptual processes.     

Semi-sparse PCA

It is well known that the classical exploratory factor analysis (EFA) of data with more observations than variables has several types of indeterminacy. We study the factor indeterminacy and show some new aspects of this problem by considering EFA as a specific data matrix decomposition. We adopt a new approach to the EFA estimation and achieve a new characterization of the factor indeterminacy problem. A new alternative model is proposed, which gives determinate factors and can be seen as a semi-sparse principal component analysis (PCA). An alternating algorithm is developed, where in each step a Procrustes problem is solved. It is demonstrated that the new model/algorithm can act as a specific sparse PCA and as a low-rank-plus-sparse matrix decomposition. Numerical examples with several large data sets illustrate the versatility of the new model, and the performance and behaviour of its algorithmic implementation.

     

Internal imagery training in active high jumpers

The main purpose of this study was to examine whether the use of internal imagery would affect high jumping performance for active high jumping athletes. Over a period of six weeks, a group of active high jumpers were trained with an internal imagery program for a total of 72 minutes. This group was compared to a control group consisting of active high jumpers that only maintained their regular work-outs during the same time period. Four variables were measured; jumping height, number of failed attempts, take-off angle, and bar clearance. There was a significant improvement on bar clearance for the group that trained imagery (p < 0.05) but not for the control group. No other differences were found. The results suggest that internal imagery training may be used to improve a component of a complex motor skill. Possible explanations and future recommendations are discussed.     

Enhanced occipital and anterior cingulate activation in men but not in women during exposure to angry and fearful male faces

Blood-oxygenation-level-dependent signal was measured with functional magnetic resonance imaging in 24 healthy young subjects (12 men and 12 women) during viewing of angry, fearful, and neutral male and female face pictures. Exposure to angry male as opposed to angry female faces activated the visual cortex and the anterior cingulate gyrus significantly more in men than in women. A similar sex-differential brain activation pattern was present during exposure to fearful but not neutral faces. Previous behavioral studies indicate enhanced physiological arousal in men but not in women during exposure to angry male as opposed to female faces, and brain imaging studies have shown that the occipital cortex and the anterior cingulate gyrus are influenced by activity in the autonomic nervous system as well as by visual attention. Hence, we suggest that the elevated occipital and anterior cingulate activation in men during confrontation with other angry and fearful males may reflect enhanced vigilance in a potentially dangerous situation.