The time course of working memory effects on visual attention

Previous work has generated inconsistent results with regard to what extent working memory (WM) content guides visual attention. Some studies found effects of easy to verbalize stimuli, whereas others only found an influence of visual memory content. To resolve this, we compared the time courses of memory-based attentional guidance for different memory types. Participants first memorized a colour, which was either easy or difficult to verbalize. They then looked for an unrelated target in a visual search display and finally completed a memory test. One of the distractors in the search display could have the memorized colour. We varied the time between the to-be-remembered colour and the search display, as well as the ease with which the colours could be verbalized. We found that the influence of easy to verbalize WM content on visual search decreased with increasing time, whereas the influence of visual WM content was sustained. However, visual working memory effects on attention also decreased when the duration of visual encoding was limited by an additional task or when the memory item was presented only briefly. We propose that for working memory effects on visual attention to be sustained, a sufficiently strong visual representation is necessary.     

Prioritizing new elements with a brief preview period: Evidence against visual marking

Watson and Humphreys (1997) have proposed that the ability to prioritize new elements over old elements involves a time-consuming process (of at least 400 msec) of active inhibition of the locations of the old elements, which they referred to asvisual marking. Recently, Donk and Theeuwes (2001) have suggested that prioritized selection of new over old elements is an instantaneous process related to the luminance change accompanying the appearance of the new elements. The aim of the present study was to test these two alternatives by investigating whether prioritized selection of new over old elements could be achieved with a very short preview of the old elements (50 msec). The results indicated that participants were able to prioritize selection of new over old elements when the new elements were presented with luminance onset whereas the old elements were not. New elements could not be prioritized if both the old and the new elements appeared with luminance onset. The results indicated that prioritization of new elements is based on an instantaneous process, rather than on a time-consuming process.     

Visual antipriming: Evidence for ongoing adjustments of superimposed visual object representations

A fundamental question of memory is whether the representations of different items are stored in localist/discrete or superimposed/overlapping manners. Neural evidence suggests that neocortical areas underlying visual object identification utilize superimposed representations that undergo continual adjustments, but there has been little corroborating behavioral evidence. We hypothesize that the representation of an object is strengthened, after it is identified, via small representational changes; this strengthening is responsible for repetition priming for that object, but it should also be responsible for antipriming of other objects that have representations superimposed with that of the primed object. Functional evidence for antipriming is reported in young adults, amnesic patients, and matched control participants, and neurocomputational models. The findings from patients dismiss explicit memory explanations, and the models fit the behavioral performance exceptionally well. Putative purposes of priming and comparisons with other theories are discussed. Priming and antipriming may reflect ongoing adjustments of superimposed representations in neocortex.     

Prioritizing selection of new elements: bottom-up versus top-down control

Watson and Humphreys (1997) have proposed that prioritized selection of new over old elements occurs because observers can apply top-down inhibition to the locations of the old elements by a mechanism they refer to as visual marking. However, recent evidence has suggested that the top-down mechanism is questionable (Donk & Theeuwes, 2001). In the present study, we investigated whether prioritized selection of new over old elements occurs in a bottom-up or a top-down fashion. Observers were presented with displays containing one set of elements (old elements) followed, after a certain time interval, by a second set of elements (new elements). The observers were instructed to search for the presence of a target that was presented with equal probability among the old and the new elements (Experiments 1 and 2) or twice as often among the old elements than among the new elements (Experiment 3). The results show that new elements were prioritized for selection over old ones even though the observers had no incentive to do so. The results suggest that prioritized selection of new over old elements is not mediated by a top-down inhibition process, as was proposed by Watson and Humphreys (1997). Instead, prioritization of new elements appears to be a bottom-up process. The implications of these results are discussed in terms of models of attentional control.     

A cross-linguistic data bank for oral picture naming in Dutch, English, German, French, Italian, Russian, Spanish, and Swedish (PEDOI)

The well established effect of word frequency on adult's picture naming performance is now called into question. This is particularly true for variables which are correlated with frequency, as is the case of age of word acquisition. Since the work of [Carrol and White, 1973] there is growing agreement among researchers to confer an important role in lexical access to this variable. Indeed, it has been shown ( [Hodgson and Ellis, 1998]) that for normal English-speaking adults only the variables 'age-of-acquisition' and 'name agreement' are independent predictors of naming success among the various variables considered. However, when brain-damaged subjects with and without degenerative pathologies are studied, word frequency and word length as well as concept familiarity all give significant effects ( [Hirsh and Funnell, 1995]; [Lambon Ralph et al., 1998]; [Nickels and Howard, 1995]). Finally, it has been suggested that the production of specific error types may be related to such variables. According to [Nickels and Howard, 1994] the production of semantic errors is specifically affected by 'imageability' and in the recent study by [Kremin et al., 2001] 'age of acquisition' predicts (frank) word finding difficulties.     

Impaired sensitivity to dynamic stimuli in poor readers of a regular orthography

The mappings from grapheme to phoneme are much less consistent in English than they are for most other languages. Therefore, the differences found between English-speaking dyslexics and controls on sensory measures of temporal processing might be related more to the irregularities of English orthography than to a general deficit affecting reading ability in all languages. However, here we show that poor readers of Norwegian, a language with a relatively regular orthography, are less sensitive than controls to dynamic visual and auditory stimuli. Consistent with results from previous studies of English-readers, detection thresholds for visual motion and auditory frequency modulation (FM) were significantly higher in 19 poor readers of Norwegian compared to 22 control readers of the same age. Over two-thirds (68.4%) of the children identified as poor readers were less sensitive than controls to either or both of the visual coherent motion or auditory 2Hz FM stimuli.     

When Gender Stereotypes Get Male Adolescents into Trouble: A Longitudinal Study on Gender Conformity Pressure as a Predictor of School Misconduct

Sex Roles - School misconduct is a threat to educational careers and learning. The present study sheds light on why male adolescents in particular are prone to school misconduct. Qualitative...     

Knowledge and Attitudes Towards Genetic Testing: A Two Year Follow-Up Study in Patients with Asthma,Diabetes Mellitus and Cardiovascular Disease

Adequate knowledge and personal attitudes towards DNA-testing are major determinants of optimal utilization of genetic testing. This study aims to (1) assess the genetic knowledge and attitude towards genetic testing of patients with asthma, diabetes mellitus type II and cardiovascular diseases, (2) determine whether their knowledge or attitude changed since 2002, and (3) investigate the predictive role of knowledge on attitude. Data were collected within the Panel of Patients with Chronic Diseases in 2002 and 2004, resulting in 398 data-pairs. Results show that factual knowledge mainly relates to associations between genes and diseases, less is known on associations between genes, chromosomes, cells and body. The perceived knowledge on DNA-testing has not increased since 2002. The attitude towards genetic testing also appeared to be rather consistent. Less perceived medical genetic knowledge and more perceived social genetic knowledge were found predictive for a more reserved attitude towards genetic testing. In conclusion, advanced developments in the field of genetics are not accompanied by increased knowledge of patients with common multi-factorial diseases. The finding that more perceived social genetic knowledge results in more reluctance can be considered an indicator for the necessity of social debates on genetic testing.     

Illness perceptions in dialysis patients and their association with quality of life

The present study explored illness perceptions of end stage renal disease (ESRD) patients on both haemodialysis (HD) and peritoneal dialysis (PD) treatment, and their associations with quality of life. Leventhal's self-regulation model (SRM) was used as a theoretical framework. Illness perceptions and quality of life were assessed with the IPQ-R and the SF-36 in 91 HD and 42 PD patients participating in the NECOSAD-study. Compared to HD patients, PD patients experienced more personal control and had a better understanding of the illness. Illness perceptions explained from 17 to 51% of the variance in quality of life scores. Perception of more symptoms, more consequences and lower personal control were associated with lower well-being. The concept of illness perceptions is useful in understanding the impact of ESRD and of dialysis treatment on quality of life. Interventions aimed at providing more knowledge about ESRD and dialysis, and provision of skills to coping with the illness and its consequences may improve quality of life in dialysis patients.     

Illness perceptions and self-care behaviours in the first years of living with type 2 diabetes; does the presence of complications matter?

Objective: To assess illness perceptions, self-care behaviours and their relationship in recently diagnosed type 2 diabetes mellitus (T2DM) patients with and without diabetes-related complications.

Design: Cross-sectional survey among 192 recently diagnosed T2DM patients of whom 23% reported the presence of diabetes-related complications. Illness perceptions and self-care were assessed by the Revised Illness Perception Questionnaire (IPQ-R) and the revised Summary of Diabetes Self-Care Activities (SDSCA) measure.

Results: Generally, participating patients perceived T2DM as a chronic, but relatively controllable condition with minor consequences. In the presence of complications, however, T2DM was perceived as more unpredictable with more (serious) consequences and less controllable by self-care or medical treatment. Furthermore, engagement in exercise and foot care was reported more often by patients with complications. Self-care was related to certain illness perception dimensions, and interactions between perceptions and complications were found.

Conclusion: T2DM patients in the first years of their illness are often recommended to make lifestyle changes in the absence of noticeable diabetes-related symptoms or complaints. As many T2DM patients do not seem to perceive their condition to be serious and postpone lifestyle changes until diabetes-related complications appear, a major challenge for professionals is to convince asymptomatic patients of the importance of self-care.