Sensory Feedback in the Learning of a Novel Motor Task

The role of different forms of feedback is examined in learning a novel motor task. Five groups of ten subjects had to learn the voluntary control of the abduction of the big toe, each under a different feedback condition (proprioceptive feedback, visual feedback, EMG feedback, tactile feedback, force feedback). The task was selected for two reasons. First, in most motor learning studies subjects have to perform simple movements which present hardly any learning problem. Second, studying the learning of a new movement can provide useful information for neuromuscular reeducation, where patients often also have to learn movements for which no control strategy exists. The results show that artificial sensory feedback (EMG feedback, force feedback) is more powerful than “natural” (proprioceptive, visual, and tactile) feedback. The implications of these results for neuromuscular reeducation are discussed.     

Learning new movement patterns: a study on good and poor writers comparing learning conditions emphasizing spatial, timing or abstract characteristics

In the earliest stages of motor-skill learning cognitive, visuo-spatial and dynamic processes play an important role. Which of these should be addressed first when children need to learn a new complex movement sequence? This study compares three learning methods in a within-subject design by having 18 good and 18 poor 8-year-old writers master unfamiliar, letter-like patterns by (1) tracing a trajectory on a screen, (2) tracking a moving target (pursuit), and (3) performing the pattern using written explicit instructions. Following each 10-trial learning phase, the children completed a short test phase. Besides errors and kinematic data, Dynamic Time Warping (DTW) was used to calculate the deviation for each pattern from the ideal shape (DTW-distance). As predicted, the number of errors and DTW-distance were very low during the learning phase of the tracing and pursuit conditions and higher in the explicit condition. Conversely, in the test phase, tracing yielded the highest DTW-distance and the explicit condition the lowest DTW-distance and error percentages. The results were remarkably similar for the good and poor writers. The poor learning results of the tracing condition and the good results of the explicit condition have important implications for the teaching of handwriting and remedial therapy.     

Changing brains, changing perspectives: the neurocognitive development of reciprocity

Adolescence is characterized by the emergence of advanced forms of social perspective taking and significant changes in social behavior. Yet little is known about how changes in social cognition are related to changes in brain function during adolescence. In this study, we investigated the neural correlates of social behavior during three phases of adolescence, carrying out functional magnetic resonance imaging of participants' brains while they were Player 2 in the Trust Game. We found that with age, adolescents were increasingly sensitive to the perspective of the other player, as indicated by their reciprocal behavior. These advanced forms of social perspective-taking behavior were associated with increased involvement of the left temporo-parietal junction and the right dorsolateral prefrontal cortex. In contrast, young adolescents showed more activity in the anterior medial prefrontal cortex, a region previously associated with self-oriented processing and mentalizing. These findings suggest that the asynchronous development of these neural systems may underlie the shift from thinking about self to thinking about the other.     

The Discrepancy Between How Women See Themselves and Feminists Predicts Identification with Feminism

Many women who accept the basic tenets of feminist ideology are reluctant to call themselves feminists, which is problematic because feminist self-identification is related to a variety of positive outcomes. The present research tests the idea that discrepancies between women’s self-view and feminist-view on the dimensions of competence and warmth are related to identification with feminism. This supposition is guided by the idea that a full understanding of why women have difficulty embracing feminism must take into account not only their view of feminists, but also whether women see themselves as different from feminists. Three online survey studies, which included 387, 288, and 116 adult U.S. women, demonstrate that perception of warmth identification with feminism was lower if women regard feminists as less warm than they see themselves. For perceptions of competence, the direction of this discrepancy was irrelevant: The more women see feminists as differently competent (i.e., higher or lower), the less they identify with feminists. Moreover, perceived discrepancy predicted identification with feminism even after controlling for women’s agreement with feminist values. Both endorsement of feminist values and perceived discrepancy are important in predicting identification with feminism and therefore practical interventions to maximize identification should target both of these components. For perceived discrepancy, interventions to reduce feminist-self discrepancies will likely be most effective if they target stereotypes of feminists as being cold.     

The frequency effect in second-language visual word recognition

A lexical decision experiment with Dutch-English bilinguals compared the effect of word frequency on visual word recognition in the first language with that in the second language. Bilinguals showed a considerably larger frequency effect in their second language, even though corpus frequency was matched across languages. Experiment 2 tested monolingual, native speakers of English on the English materials from Experiment 1. This yielded a frequency effect comparable to that of the bilinguals in Dutch (their L1). These results constrain the way in which existing models of word recognition can be extended to unbalanced bilingualism. In particular, the results are compatible with a theory by which the frequency effect originates from implicit learning. They are also compatible with models that attribute frequency effects to serial search in frequency-ordered bins (Murray & Forster, 2004), if these models are extended with the assumption that scanning speed is language dependent, or that bins are not language specific.     

Haptic pop-out in a hand sweep

Visually, a red item is easily detected among green items, whereas a mirrored S among normal Ss is not. In visual search, the former is known as the pop-out effect. In daily life, people often also conduct haptic (tactual) searches, for instance, when trying to find keys in their pocket. The aim of the present research was to determine whether there is a haptic version of the pop-out effect. Blindfolded subjects had to search for a target item which differed in roughness from the surrounding distractor items. We report reaction time slopes as low as 20 ms/item. When target and distractor identities were interchanged the slopes increased indicating a search asymmetry. Furthermore, we show that differences in search slope were accompanied by search strategy differences. In some conditions a single-hand sweep over the display was sufficient, while in others a more detailed search strategy was used. By relating haptic search slopes to parallel and serial search strategies we show, for the first time, that pop-out effects occur under free manual exploration.     

Thermosensory reversal effect quantified

At room temperature, some materials feel colder than others due to differences in thermal conductivity, heat capacity and geometry. When the ambient temperature is well above skin temperature, the roles of ‘cold’ and ‘warm’ materials are reversed. In this paper, this effect is quantified by measuring discrimination thresholds for subjective coldness at different ambient temperatures using stimuli of different thicknesses. The reversal point was found to be at 34 °C, somewhat above skin temperature. At this reversal point, discrimination is quite impossible. At room temperature, subjects were able to discriminate between stimuli of different thickness based on subjective coldness, showing that the sense of touch, unlike vision, can penetrate solid objects. Furthermore, somewhat surprisingly, at ambient temperatures well below normal room temperature, discrimination is worse than at room temperature.     

The SNARC effect in the processing of second-language number words: further evidence for strong lexico-semantic connections

We present new evidence that word translation involves semantic mediation. It has been shown that participants react faster to small numbers with their left hand and to large numbers with their right hand. This SNARC (spatial-numerical association of response codes) effect is due to the fact that in Western cultures the semantic number line is oriented from left (small) to right (large). We obtained a SNARC effect when participants had to indicate the parity of second-language (L2) number words, but not when they had to indicate whether L2 number words contained a particular sound. Crucially, the SNARC effect was also obtained in a translation verification task, indicating that this task involved the activation of number magnitude.     

WordGen: a tool for word selection and nonword generation in Dutch, English, German, and French.

WordGen is an easy-to-use program that uses the CELEX and Lexique lexical databases for word selection and nonword generation in Dutch, English, German, and French. Items can be generated in these four languages, specifying any combination of seven linguistic constraints: number of letters, neighborhood size, frequency, summated position-nonspecific bigram frequency, minimum position-nonspecific bigram f requency, position-specific frequency of the initial and final bigram, and orthographic relatedness. The program also has a module to calculate the respective values of these variables for items that have already been constructed, either with the program or taken from earlier studies. Stimulus queries can be entered through WordGen's graphical user interface or by means of batch files. WordGen is especially useful for (1) Dutch and German item generation, because no such stimulus-selection tool exists for these languages, (2) the generation of nonwords for all four languages, because our program has some important advantages over previous nonword generation approaches, and (3) psycholinguistic experiments on bilingualism, because the possibility of using the same tool for different languages increases the cross-linguistic comparability of the generated item lists. WordGen is free and available at http://expsy.ugent.be/wordgen.htm.     

“Logic of artistic development: the case of Mondrian” [New Ideas in Psychology 21 (2003) 221-246]

In this article I show how we can give a formal representation and analysis of evolutions in artistic style, using the work of the painter Mondrian as an example. Capitalising on the idea that radical change in thought implies related changes in judgement criteria, we can in a ‘‘logic of development’’ specify the relations within, and between, those different sets of artistic judgement criteria that are considered typical of successive stages in artistic development. I discuss some of the problems involved in dealing with post-conventional thinking and judgement. Then I propose five major steps in Mondrian's artistic quest, showing how it is different—and how different it is—from other kinds of (e.g. moral or aesthetic) judgement development. Whereas many kinds of conceptual development lead to (various types of) criterion expansion, this form of entirely postconventional development goes in the opposite direction of a most stringent criterion reduction.