119 research outputs found

    The exterior-letter advantage in linear multi-letter arrays

    Get PDF
    When linear arrays of unrelated letters (e.g., 'sfdthnc') are presented tachistoscopically centred across a fixation point, letters presented at exterior positions (e.g., 's----c') aregenerally reported more accurately than letters presented in interior positions. This "exterior-letter advantage" suggests that processing is more efficient for exterior letters than for interior letters. Previous researchers have argued that the exterior-letter advantage can be fully accounted for by the influences of lateral interference and mask configuration. However, the processes responsible for the exterior-letter advantage are far from resolved, despite the robustness of the phenomenon and its occurrence in numerous investigations into visual information processing. The experiments reported in this study investigated the role of lateral interference and backward pattern masking in the exterior-letter advantage. To investigate the role of lateral interference, performance was compared across complete 7-letter arrays and arrays in which the presence and proximity of flanking letters was varied by (i) presenting only exterior letters and their immediately flanking interior letter, (ii) varying the number blank letter-spaces by which these letter-pairs were separated, (iii) varying the nature of the characters presented in these displays, and (iv) presenting each exterior/interior letter-pair in isolation. The role of backward pattern masking was investigated (i) using different mask configurations which either matched or exceeded the left and right boundaries of complete letter arrays, and (ii) using masks which overlay only the positions of each exterior/interior letter-pair. The findings indicate that while lateral interference and mask configuration each played a part, neither an imbalance in the number of immediately flanking letters for interior and exterior letters nor mask configuration can entirely account for the exterior-letter advantage

    The potential for prevention of dementia across two decades: The prospective, population-based Rotterdam Study

    Get PDF
    Background: Cardiovascular factors and low education are important risk factors of dementia. We provide contemporary estimates of the proportion of dementia cases that could be prevented if modifiable risk factors were eliminated, i.e., population attributable risk (PAR). Furthermore, we studied whether the PAR has changed across the last two decades. Methods: We included 7,003 participants of the original cohort (starting in 1990) and 2,953 participants of the extended cohort (starting in 2000) of the Rotterdam Study. Both cohorts were followed for dementia until ten years after baseline. We calculated the PAR of overweight, hypertension, diabetes mellitus, cholesterol, smoking, and education. Additionally, we assessed the PAR of stroke, coronary heart disease, heart failure, and atrial fibrillation. We calculated the PAR for each risk factor separately and the combined PAR taking into account the interaction of risk factors. Results: During 57,996 person-years, 624 participants of the original cohort developed dementia, and during 26,177 person-years, 145 participants of the extended cohort developed dementia. The combined PAR in the original cohort was 0.23 (95 % CI, 0.05-0.62). The PAR in the extended cohort was slightly higher at 0.30 (95 % CI, 0.06-0.76). The combined PAR including cardiovascular diseases was 0.25 (95 % CI, 0.07-0.62) in the original cohort and 0.33 (95 % CI, 0.07-0.77) in the extended cohort. Conclusions: A substantial part of dementia cases could be prevented if modifiable risk factors would be eliminated. Although prevention and treatment options of cardiovascular risk factors and diseases have improved, the preventive potential for dementia has not declined over the last two decades

    An adverse tumor-protective effect of IDO1 inhibition

    Get PDF
    By restoring tryptophan, indoleamine 2,3-dioxygenase 1 (IDO1) inhibitors aim to reactivate anti-tumor T cells. However, a phase III trial assessing their clinical benefit failed, prompting us to revisit the role of IDO1 in tumor cells under T cell attack. We show here that IDO1 inhibition leads to an adverse protection of melanoma cells to T cell-derived interferon-gamma (IFNγ). RNA sequencing and ribosome profiling shows that IFNγ shuts down general protein translation, which is reversed by IDO1 inhibition. Impaired translation is accompanied by an amino acid deprivation-dependent stress response driving activating transcription factor-4 (ATF4)high/microphtalmia-associated transcription factor (MITF)low transcriptomic signatures, also in patient melanomas. Single-cell sequencing analysis reveals that MITF downregulation upon immune checkpoint blockade treatment predicts improved patient outcome. Conversely, MITF restoration in cultured melanoma cells causes T cell resistance. These results highlight the critical role of tryptophan and MITF in the melanoma response to T cell-derived IFNγ and uncover an unexpected negative consequence of IDO1 inhibition

    The Effects of Visual Information on Users' Mental Models: An Evaluation of Pathfinder Analysis as a Measure of Icon Usability

    Get PDF
    Research has shown that individuals' knowledge structures change as a result of learning and experience. This article investigates the possibility that the content of graphical user interfaces can play a role in determining the nature of the knowledge structures users develop. Users employed either concrete, abstract, or arbitrary icon sets in a computer-based problem-solving task. The effects of these icons were assessed using standard measures of performance. On the basis of the assumption that users' mental models should be better if appropriate icons were presented on the interface, Pathfinder analysis was used to elicit users' knowledge structures as they gained experience with the interface. The efficacy of this measure was then compared with performance measures. Our findings show that users' knowledge structures do depend on the nature of the graphical information presented at the interface but do not rely as much on the use of the visual metaphor as previously thought. Although most measures were sensitive to initial differences between icon sets, only some measures were sensitive to the long-term differences that remained after users had gained experience with the icon set. The implications of these findings for interface design are discussed
    corecore