Effects of observing and producing deictic gestures on memory and learning in different age groups

The studies presented in this dissertation aimed to investigate whether observing or producing deictic gestures (i.e., pointing and tracing gestures to index a referent in space or a movement pathway), could facilitate memory and learning in children, young adults, and older adults. More specifically, regarding memory it was investigated whether the use of deictic gestures would improve performance on tasks targeting cognitive functions that are found to change with age (working memory, cognitive control, and source memory). In addition, it was investigated whether any found effects would be more pronounced for children in whom these cognitive functions are still developing, and for older adults, in whom these cognitive functions have been found to suffer from age-related declines

Compensatory effects of pointing and predictive cueing on age-related declines in visuospatial working memory

In this study, we investigated whether the visuospatial working memory performance of young and older adults would improve if they used a multimodal as compared with a unimodal encoding strategy, and whether or not visual cues would add to this effect. In Experiment 1, participants were presented with trials consisting of an array of squares and an array of circles. They were instructed to point at one type of figure (multimodal encoding strategy) and only to observe the other (unimodal encoding strategy). After each trial, an immediate location recognition test of one of the two arrays followed. In Experiment 2, the same task was used, but a cue was provided, either before or after the encoding phase, indicating which of the two arrays would be tested. Our results showed that a multimodal, as compared with a unimodal, encoding strategy improved visuospatial working memory performance in both young and older adults (Exp. 1), and that adding visual cues to the multimodal but not to the unimodal encoding strategy improved older adults’ performance up to the level of young adults (Exp. 2). In both age groups, cueing after encoding led to higher performance in the multimodal than in the unimodal condition when the second array was tested. However, cueing before encoding led to higher performance in the multimodal than in the unimodal condition when the first array of the figure sequence was tested. These results suggest that pointing together with predictive cueing can have beneficial effects on visuospatial working memory, which is especially important for older adults

Action-speech and gesture-speech integration in younger and older adults: An event-related potential study

In daily communication, speech is enriched with co-speech gestures, providing a visual context for the linguistic message. It has been shown that older adults are less sensitive to incongruencies between context (e.g., a sentence) and target (e.g., a final sentence word). This is evidenced by a smaller and delayed N400 (in)congruency effect that reflects the difference between the N400 component in response to congruent versus incongruent targets. The present study investigated whether the effect of age on the N400 effect in sentence-final word integration would also arise for verb-gesture/action integration. Assuming that gestures have a tight connection to language these would provide a higher contextual constraint for the action phrase than the literal actions (i.e., an action performed on an object can be understood in isolation, without the action phrase). EEG was recorded from a sample of younger and older participants, while they watched audio-visual stimuli of a human actor performing an action or pantomime gesture while hearing a congruent or incongruent action phrase. Results showed that the N400 (in)congruency effect was less widespread in the older than the younger adults. It seemed that older adults, but not younger adults were less sensitive to the gestural than the action (object) information when processing an action phrase

Lactobacillus reuteri inhibition of Enteropathogenic Escherichia coli adherence to human intestinal epithelium

Enteropathogenic Escherichia coli (EPEC) is a major cause of diarrheal infant death in developing countries, and probiotic bacteria have been shown to provide health benefits in gastrointestinal infections. In this study, we have investigated the influence of the gut symbiont Lactobacillus reuteri on EPEC adherence to the human intestinal epithelium. Different host cell model systems including non-mucus-producing HT-29 and mucus-producing LS174T intestinal epithelial cell lines as well as human small intestinal biopsies were used. Adherence of L. reuteri to HT-29 cells was strain-specific, and the mucus-binding proteins CmbA and MUB increased binding to both HT-29 and LS174T cells. L. reuteri ATCC PTA 6475 and ATCC 53608 significantly inhibited EPEC binding to HT-29 but not LS174T cells. While pre-incubation of LS174T cells with ATCC PTA 6475 did not affect EPEC attaching/effacing (A/E) lesion formation, it increased the size of EPEC microcolonies. ATCC PTA 6475 and ATCC 53608 binding to the mucus layer resulted in decreased EPEC adherence to small intestinal biopsy epithelium. Our findings show that L. reuteri reduction of EPEC adhesion is strain-specific and has the potential to target either the epithelium or the mucus layer, providing further rationale for the selection of probiotic strains

Schoolcompositie en kenmerken van docentkwaliteit op VO-scholen. Resultaten van secundaire analyses op de Nederlandse data in het OESO-TALIS 2013 bestand.

In deze studie worden de resultaten gerapporteerd van secundaire analyses op de Nederlandse data van het Teaching and Learning International Survey (TALIS) onderzoek van de OESO. Onderzocht werd of schoolcompositie en ervaring een verband hadden met werktevredenheid, kenmerken van docentkwaliteit en behoefte aan professionalisering op het gebied van diversiteit. Uit de resultaten blijkt dat docenten op scholen met relatief veel leerlingen met een lage sociaaleconomische achtergrond, minder tevreden zijn met hun beroep, minder vertrouwen i

Effects of pointing gestures on memory for (in)congruent stimuli in children and young adults.

We investigated whether finger pointing toward picture locations can be used as an external cognitive control tool to guide attention and compensate for the immature cognitive control functions in children compared with young adults. Item and source memory performance was compared for picture-location pairs that were either semantically congruent (e.g., a cloud presented at the upper half of the screen) or incongruent (e.g., a cloud presented at the lower part of the screen). Contrary to our expectations, pointing had an adverse eff

Co-thought gesturing supports more complex problem solving in subjects with lower visual working-memory capacity

During silent problem solving, hand gestures arise that have no communicative intent. The role of such co-thought gestures in cognition has been understudied in cognitive research as compared to co-speech gestures. We investigated whether gesticulation during silent problem solving supported subsequent performance in a Tower of Hanoi problem-solving task, in relation to visual working-memory capacity and task complexity. Seventy-six participants were assigned to either an instructed gesture condition or a condition that allowed them to gesture, but without explicit instructions to do so. This resulted in th