Vanishing white matter disease: a review with focus on its genetics

Leukoencephalopathy with vanishing white matter (VWM) is an autosomal recessive brain disorder, most often with a childhood onset. Magnetic resonance imaging and spectroscopy indicate that, with time, increasing amounts of cerebral white matter vanish and are replaced by fluid. Autopsy confirms white matter rarefaction and cystic degeneration. The process of localization and identification of the first two genes related to VWM, EIF2B5 and EIF2B2, was facilitated by two founder effects in the Dutch population. EIF2B5 and EIF2B2 encode the epsilon and beta subunits of translation initiation factor eIF2B. Soon it was shown that mutations in all five eIF2B subunit genes can cause VWM. EIF2B is essential for the initiation of translation of RNA into protein and is involved in regulation of the process, especially under stress conditions, which may explain the sensitivity to stress conditions observed in VWM patients. The pathophysiology of the disease is still poorly understood.     

How do health and biological age influence chronological age and sex differences in cognitive aging: moderating, mediating, or both?

Much research on cognitive competence in normal older adults has documented age and sex differences. The authors used new cross-sectional data from the Victoria Longitudinal Study (VLS) (n=386; age 61 to 95 years) to examine how health and biological age influence age and sex differences in cognitive aging. The authors found evidence for both moderating and mediating influences. Age differences were moderated by health status, such that the negative effects of age were most pronounced among participants of relatively better health. Sex differences were moderated by health and were more pronounced among participants reporting comparatively poorer health. Although health mediated a notable amount of age-related cognitive variation, BioAge mediated considerably more variance, even after statistical control for differences in health. A complex pattern emerged for the mediation of sex differences: Although BioAge accounted for sex-related variation in cognitive performance, health operated to suppress these differences. Overall, both health and BioAge predicted cognitive variation independently of chronological age.     

Symmetry and repetition in perspective

Although ecologically relevant, perspective views of symmetries and repetitions have hardly been investigated. Any symmetry or repetition that is not oriented orthogonally to the line of sight yields perspective distortions on the retina. In this study, these distortions are analyzed in terms of first-order structures (i.e., virtual lines between corresponding points) and second-order structures (i.e., correlation quadrangles formed by two virtual lines). In the literature, these structures have been proposed to guide the detection of fron to parallel symmetry and repetition. But what about perspective views? First, the analysis in this study shows that perspective distorts the retinal first-order and second-order structures of symmetry and repetition differently. Second, the results of two experiments on this distortion difference suggest that, in perspective views, symmetry and repetition detection is not preceded by normalization but occurs directly on the basis of the retinal first-order and second-order structures.     

Does the order of head noun and modifier explain response times in conceptual combination?

We describe a speeded sensibility judgment experiment in which noun-noun combinations in the Indonesian language were used that parallels Gagné and Shoben's (1997) study of combinations in the English language. Like English, Indonesian is read from left to right and contains noun-noun combinations that are formed by juxtaposing the nouns. However, unlike in English, the order of the modifier and the head noun is reversed. This difference between English and Indonesian combinations allowed us to assess whether sensibility judgments of combinations are affected primarily by the left-right order of the nouns or by different functional roles of the nouns (i.e., modifier vs. head noun). As in Gagné and Shoben's study, the modifier's relation frequency contributed significantly to predicting sensibility judgment times in a regression analysis, but the head noun's relation frequency did not. We discuss the implications of this finding for models of conceptual combination.     

The novelty effect: support for the Novelty-Encoding Hypothesis

In two experiments, we examined the "Novelty-Encoding Hypothesis" proposed by Tulving and Kroll (1995), suggesting that the encoding of online information into long-term memory is influenced by its novelty and that novelty increases recognition performance. In Phase 1 (familiarization phase), subjects participated in a standard memory experiment in which different types of materials (verbs and nouns) were studied under different encoding conditions (enactment and non-enactment) and were tested by an expected recognition test. In Phase 2 (critical phase), subjects evaluated the materials (both familiar materials which were encoded earlier in Phase 1, and novel materials which were not presented earlier in Phase 1) in a frequency judgment task and were given an unexpected recognition test. The results of both experiments showed that novel items were recognized better than familiar items. This result held true for both hit rates - false alarms and hit rates. The novelty effect was observed for different subjects (Swedish and Japanese), different materials (verbs and nouns; high frequency and low frequency), and different types of encoding in Phase 1 (enactment and non-enactment). These findings provide support for the "Novelty-Encoding Hypothesis" stating that the effect is based on the encoding of target items at the time of the critical study (Phase 2). A comparison between the present experiments and the Tulving and Kroll (1995), Dobbins, Kroll, Yonelinas & Liu (1998) and Greene (1999) studies suggests that the novelty effect is more pronounced under incidental encoding than under intentional encoding.     

Transistorized timer for sensory-behavioral research

A timer circuit is presented that can produce pulse durations ranging from 1 to 20,000 msec. The timer has high reliability, is inexpensive, and simple to construct.     

The role of dark pattern stimuli and personality in online impulse shopping: An application of S-O-R theory

Online impulse shopping is a growing industry. This paper uses the Stimulus-Organism-Response framework to model online impulse purchase behavior using a novel combination of stimuli and organism characteristics. The stimuli: social proof, limited-quantity scarcity, and high-demand, are three commonly used website features known as dark patterns. The organism characteristic personality is measured by the big 5 personality traits and persona generated through latent profile analysis. Using the machine learning algorithm XGBoost, impulse purchasing response was predicted separately for each dark pattern stimuli. Results show personality characteristics are important features when predicting consumer impulse purchasing in response to dark pattern messages. Moreover, the personality traits (and personas) most predictive of impulse shopping behavior varied by type of dark pattern. Findings suggest personality influences susceptibility to different dark patterns, indicating a need for tailored interventions to mitigate individual consumer vulnerabilities to impulse shopping.     

Mead, Intersubjectivity, and Education: The Early Writings

This article seeks to reconstruct the early writings of George Herbert Mead in order to explore the significance of his work for the development of an intersubjective conception of education. The reconstruction takes its point of departure in Mead's claim that reflective consciousness has a social situation as its precondition. In a mainly chronological account of Mead's writings on psychology and philosophy from the period 1900–1925, it is shown how Mead explains the social origin of conscious reflection and self-consciousness. It is further shown, how Mead redefines the social in terms of meaningful, creative, radically undetermined, but not yet conscious, interaction. Mead's position thereby implies a reversal of the traditional way in which the relationship between subjectivity and intersubjectivity is conceived. The article ends with an outline of the main implications of this reversal for our understanding of education.     

Analyzing experimental data using the Rasch model

We present a method for studying experimental data based on a psychometric model, the “Rasch model” (Rasch, 1966; Thissen & Steinberg, 1986). We illustrate the method with the use of a data set in the field of concept research. More specifically, we investigate whether a conjunctive concept can be seen as an additive combination of its constituents. High correlations between model and data are obtained, but a formal goodness-of-fit test indicates that the model does not completely account for the data. We then alter the Rasch model in such a way as to capture our idea of why the model deviates from the data. This results in higher correlations and a strong increase in goodness-of-fit. It is concluded that our ideas, as incorporated in the model, adequately summarize the data. More generally, this research illustrates that applying the Rasch model and altering it according to one’s hypotheses is an excellent way to analyze experimental data.     

The role of enactment in implicit and explicit memory

Enactment during the encoding of simple imperatives has been found to improve substantially performance on conceptually driven explicit-memory tests. In two experiments the effect of this manipulation on a conceptually driven implicit test (category association) was studied. A conceptually driven explicit test (free recall) was also included. In Experiment one three different study conditions (enactment with real objects, reading, and generation) were considered. In Experiment two there were two study conditions (enactment with imaginary objects and reading). Compared to reading, generation was found to improve the performance on both free recall and category association, whereas enactment affected free recall only. In a final experiment subjects imagined that they performed the tasks, and this manipulation was found to improve the memory performance on both tests. Taken together, this pattern of results is interpreted as suggesting that free recall and category association have a process in common that is sensitive to semantic processing at study (promoted by generation and imagery, but not by enactment), and that free recall involves a retrieval process in addition that is facilitated by a rich encoding environment (provided by enactment).