Semantic access in number word translation: the role of crosslingual lexical similarity

The revised hierarchical model of bilingualism (e.g., Kroll & Stewart, 1994) assumes that second language (L2) words primarily access semantics through their first language (L1) translation equivalents. Consequently, backward translation from L2 to L1 should not imply semantic access but occurs through lexical wordform associations. However, recent research with Dutch-French bilinguals showed that both backward and forward translation of number words yields a semantic number magnitude effect (Duyck & Brysbaert, 2004), providing evidence for strong form-to-meaning mappings of L2 number words. In two number-word translation experiments with Dutch-English-German trilinguals, the present study investigated whether semantic access in L1-L2 and L1-L3 number-word translation depends on lexical similarity of the languages involved. We found that backward translation from these more similar language pairs to L1 still yields a semantic magnitude effect, whereas forward translation does not, in contrast with the Dutch-French results of Duyck and Brysbaert (2004). We argue against a dual route model of word translation and suggest that the degree of semantic activation in translation depends on lexical form overlap between translation equivalents.     

The care-system for homeless youth in The Netherlands: perceptions of youngsters through a peer research approach

The aim of this study was to examine the perceptions of homeless youth of the care they receive. Since we wanted to involve homeless youth as participants in this project, we adopted the approach of peer-research. This form of collaborative research has a major role for homeless youth in making an inventory of the problems. A parallel is drawn between the parent-adolescent relationship and the relationship between social worker and homeless adolescent.     

Discrimination of possible and impossible objects in infancy

Adults can use pictorial depth cues to infer three-dimensional structure in two-dimensional depictions of objects. The age at which infants respond to the same kinds of visual information has not been determined, and theories about the underlying developmental mechanisms remain controversial. In this study, we used a visual habituation/novelty-preference procedure to assess the ability of 4-month-old infants to discriminate between two-dimensional depictions of structurally possible and impossible objects. Results indicate that young infants are sensitive to junction structures and interposition cues associated with pictorial depth and can detect inconsistent relationships among these cues that render an object impossible. Our results provide important insights into the development of mechanisms for processing pictorial depth cues that allow adults to extract three-dimensional structure from pictures of objects.     

Mechanisms of modal and amodal interpolation

P. J. Kellman and T. F. Shipley (1992) and P. J. Kellman, P. Garrigan, and T. F. Shipley (2005) suggested that completion of partly occluded objects and illusory objects involve the same or similar mechanisms at critical stages of contour interpolation. B. L. Anderson, M. Singh, and R. W. Fleming and B. L. Anderson (2007) presented a number of arguments against this view. The author analyzes 3 of these arguments, as well as B. L. Anderson's ecological justification for believing that these mechanisms must be very different, and suggests that their conclusions are unwarranted. The author also outlines a model consistent with the identity hypothesis and with recent physiological evidence, including a quantitative proposal for contour interpolation strength. The model suggests that V1 and V2 receive from higher visual areas feedback that modulates their responses to stimuli eliciting modal completion, amodal completion, and collinear contour facilitation. The model qualitatively explains the unstable percepts evoked by various recently devised stimuli.     

Temporal reproduction: further evidence for two processes

Some authors have suggested separate mechanisms for the processing of temporal intervals above versus below 2-3s. Given that the evidence is mixed, the present experiment was carried out as a critical test of the separate-mechanism hypothesis. Subjects reproduced five standard durations of 1-5s presented in the auditory and visual modalities. The Corsi-block test was used to assess effects of working-memory span on different interval lengths. Greater working-memory span was associated with longer reproductions of intervals of 3-5s. A factor analysis run on mean reproduced intervals revealed one modality-unspecific factor for durations of 1-2s and two modality-specific factors for longer intervals. These results are interpreted as further indications that two different processes underlie temporal reproductions of shorter and longer intervals.     

Motion misperception caused by feedback connections: A neural model simulating the Fröhlich effect

When asked to indicate the starting position of a fast moving stimulus, observers do not indicate the actual starting position but a later position on the motion trajectory. This perceptual illusion is known as the “Fröhlich effect”. We present a neural model aimed at simulating this phenomenon based on feedforward and feedback connections. The basic simulation mechanisms seem to be compatible with the attentional and the motion extrapolation account. A comparison between simulated and empirical results showed that the model is capable of generating the same main effects as those found in the empirical data.     

A reevaluation of the effect of velocity on induced motion

Induced motion (IM) was measured as a function of the temporal frequency of inducer oscillation. IM magnitude decreased as frequency increased above 5 Hz. Increasing the amplitude of inducer motion, and thereby its velocity, did not influence the temporal frequency dependence of IM. This suggests that it is the duration of inducer motion, rather than its velocity, that is the critical stimulus feature in studies that report decreased IM with higher frequencies of inducer oscillation. In a separate experiment, the optokinetic nystagmus elicited by the inducing stimulus in the absence of a fixation target displayed frequency-response characteristics similar to those of IM. This finding supports the hypothesis that IM magnitude is proportional to the voluntary effort required to suppress reflexive eye movements while maintaining stable fixation.