Rhyming words and onset-rime constituents: an inquiry into structural breaking points and emergent boundaries in the syllable

Geudens and Sandra, in their 2003 study, investigated the special role of onsets and rimes in Dutch-speaking children's explicit phonological awareness. In the current study, we tapped implicit phonological knowledge using forced-choice similarity judgment (Experiment 1) and recall of syllable lists (Experiment 2). In Experiment 1, Dutch-speaking prereaders judged rime-sharing pseudowords (/fas/-/mas/) to sound more similar than pseudowords sharing an equally sized nonrime unit (/fas/-/fak/). However, in a syllable recall task (/tepsilonf/, /ris/, /nal/), Dutch-speaking prereaders were as likely to produce recombination errors that broke up the rime (/tepsilons/) as to produce errors that retained the rime (/repsilonf/). Thus, a rime effect was obtained in a task that highlighted the phonological similarity between items sharing their rimes, but this effect disappeared in tasks without repetition of rime units. We conclude that children's sensitivity to rimes depends on similarity relations and might not reflect a fixed perceived structure of spoken syllables.     

Pointing out of the picture

The eyes of portrayed people are often noticed to 'follow you' when you move with respect to a flat painting or photograph. We investigated this well-known effect through extensive measurements of pictorial relief and apparent orientation of the picture surface for a number of viewing conditions, including frontal and oblique views. We conclude that cases of both oblique and frontal viewing are very similar in that perception simply follows what is indicated by the proximal stimulus, even though this may imply that the (perceived) physical and pictorial spaces segregate. The effect of foreshortening then causes an apparent narrowing of pictorial objects. We find no evidence for any 'correction' mechanisms that might be specifically active in oblique viewing conditions.     

Segmenting two-phoneme syllables: developmental differences in relation with early reading skills

This study explored developmental differences in children's segmentation skills of VC and CV syllables (e.g., /af/ and /fa/) in relation to their early reading abilities. To this end, we followed a subgroup of Dutch speaking prereaders who participated in, and replicated the segmentation task in first grade, at the outset of phonics reading instruction. Reading abilities were assessed after 6 and 9 months. First, we confirmed that VCs offer an easier context to isolate phonemes than CVs. Second, matching analyses showed that this development from VC to CV segmentation posed comparatively increasing difficulties for poor segmenters. Third, this qualitatively different development was reflected in early reading performance. Our data emphasize the importance of phonetic factors and instruction-based experiences in phonological development.     

Haptic detection of sine-wave gratings

We studied human haptic perception of sine-wave gratings. In the first experiment we measured the dependence of amplitude detection thresholds on the number of cycles and on the wavelength of the gratings. In haptic perception of sine-wave gratings, the results are in agreement with neural summation. The rate at which detection thresholds decrease with increasing number of cycles is much higher than can be accounted for by probability summation alone. Further, neural summation mechanisms describe the detection thresholds accurately over the whole spatial range probed in the experiment, that is wavelengths from 14 mm up to 225 mm. Earlier, we found a power-law dependence of thresholds on the spatial width of Gaussian profiles (Louw et al, 2000 Experimental Brain Research 132 369-374). The current results extend these findings; the power-law dependence holds not only for Gaussian profiles, but also for a broad range of sine-wave gratings with the number of cycles varying between 1 and 8. Haptic perception involves tactual scanning combined with an active, dynamic exploration of the environment. We measured characteristics of the velocity and force with which stimuli were scanned while performing a psychophysical task. One particularly surprising finding was that, without being instructed, participants maintained an almost constant scanning velocity during each 45-min session. A constant velocity in successive trials of the experiment might facilitate or even be necessary for discrimination. Further, a large systematic dependence of velocity on scanning length was found. An eightfold increase in scanning length resulted in about a fourfold increase in scanning velocity. A second experiment was conducted to study the influence of scanning velocity on psychophysical detection thresholds. This was done by systematically imposing specific scanning velocities to the participants while the thresholds were measured. The main result of the second experiment was that psychophysical detection thresholds are constant over a relatively broad range of scanning velocities.     

Influence of shape on haptic curvature perception

Curvature discrimination of hand-sized doubly curved surfaces by means of static touch was investigated. Stimuli consisted of hyperbolical, cylindrical, elliptical and spherical surfaces of various curvatures. In the first experiment subjects had to discriminate the curvature along a specified orientation (the discrimination orientation) of a doubly curved surface from a flat surface. The curvature to be discriminated was oriented either along the middle finger or across the middle finger of the right hand. Independent of the shape of the surface, thresholds were found to be about 1.6 times smaller along the middle finger than across the middle finger. Discrimination biases were found to be strongly influenced by the shape of the surface; subjects judged a curvature to be more convex when the perpendicular curvature was convex than when this curvature was concave. With the results of the second experiment it could be ruled out that the influence of shape on curvature perception was simply due to a systematic error made by the subject regarding the discrimination orientation.     

Haptic curvature discrimination at several regions of the hand

Static haptic discrimination of the curvature of convex, concave, or straight 20-cm-long strips was investigated for nine placements on the hand. In one condition, the strips were touched with the palmar side of the hand, and in the other condition, with the dorsal side. The influence of the lengths of the strips, and thus of contact lengths, was also investigated. For all placements, discrimination was poorer in the dorsal than in the palmar condition, owing to poorer cutaneous resolution on the dorsal side of the hand (the kinesthetic stimulation was the same in both conditions). Thus cutaneous stimulation is important. In both experiments, performance appeared to depend primarily on contact length. Moreover, the discrimination thresholds for all different placements and contact lengths followed the same trend. We conclude that in these experiments the effective stimulus for the discrimination of curved strips is the total difference of local surface attitude—that is, the slope difference over the far ends of the stimulus.     

Curvature affects haptic length perception

One possible way of haptically perceiving length is to trace a path with one’s index finger and estimate the distance traversed. Here, we present an experiment in which observers judge the lengths of paths across cylindrically curved surfaces. We found that convex and concave surfaces had qualitatively different effects: convex lengths were overestimated, whereas concave lengths were underestimated. In addition, we observed that the index finger moved more slowly across the convex surface than across the concave one. As a result, movement times for convex lengths were longer. The considerable correlation between movement times and length estimates suggests that observers take the duration of movement as their primary measure of perceived length, but disregard movement speeds. Several mechanisms that could underlie observers’ failure to account for speed differences are considered.     

Evidence for attenuated affective processing in obesity

Attenuated affective processing is hypothesized to play a role in the development and maintenance of obesity. Using an affective priming task measuring automatic affective processing of verbal stimuli, a group of 30 obese participants in a weight-loss program at the Psychosomatic University Clinic Bonn (M age = 48.3, SD = 10.7) was compared with a group of 25 participants of normal weight (M age = 43.6, SD = 12.5). A smaller affective priming effect was observed for participants with obesity, indicating less pronounced reactions to valenced adjectives. The generally reduced affective processing in obese participants was discussed as a possible factor in the etiology of obesity. Individuals who generally show less pronounced affective reactions to a given stimulus may also react with less negative affect when confronted with weight gain or less positive affect when weight is lost. Consequently, they could be expected to be less motivated to stop overeating or to engage in dieting and will have a higher risk of becoming or staying obese.     

A validation and short form of the Basic Character Inventory

The Basic Character Inventory (BCI) contains 136 items, 17 lower-order personality factors and three higher-order personality factors derived from psychoanalytic theory: Oral, Obsessive Compulsion, and Hysteria. Previous research that investigated the BCI's psychometric properties examined small, special populations and did not use modern statistical methods to validate the BCI. The present study validates the BCI via confirmatory factor analyses using a large sample of 6,285 Norwegian nursing and teaching students. Reliability, convergent validity, and divergent validity of the BCI were also assessed. Results indicated general support for the original BCI factor structure in a reduced form of the BCI that possesses strong reliability and validity, and is suitable for use in time-limited measurement settings.     

One, two, three, many - Subitizing in active touch

‘Subitizing’ refers to rapid and accurate judgement of small numbers of items, while response times and error rates increase rapidly for larger set-sizes. Most enumeration studies have been done in vision. Enumeration studies in touch have mostly involved ‘passive touch’, i.e. touch without active exploration. In daily life a much more common situation is that of ‘active touch’, e.g. when we count the number of coins in our pocket. To investigate numerosity judgement in active touch, we let subjects haptically explore varying numbers of spheres. Our results show that enumeration for up to 3 items is more efficient than for larger numbers of items. We also show that enumeration in this regime was not performed through estimation. Furthermore, it is shown that numerosity information was accessed directly and not through mass or volume cues. Not only do our results show that a haptic version of subitizing exists in active touch, they also suggest similar underlying enumeration mechanisms across different modalities.