Audio-visual interactions in binocular rivalry using the Shepard illusion in the auditory and visual domain

When both eyes are presented with dissimilar images, human observers report alternating percepts - a phenomenon known as binocular rivalry. Subjects were presented dichoptically with (1) a looming/receding starfield or (2) a looming/receding Shepard Zoom (Berger, Siggraph 2003), the visual equivalent of the Shepard tone illusion. In four psychophysical experiments, we investigated the influence of (1) a real complex tone rising/falling in pitch and (2) rising/falling Shepard tones on the dominance and suppression times of the rivaling visual motion percepts (relative to non-motion sounds or no sounds). First, we observed longer dominance times of looming than receding visual percepts even in the absence of sound. Second, auditory looming signals enhanced this looming bias by lengthening the dominance periods of their congruent visual looming percept. Third, receding auditory motion signals reduced the perceptual looming bias, though this effect was less pronounced and not consistently observed. Collectively, the results show that the perceptual predominance of looming relative to receding visual motion is amplified by congruent looming/receding auditory signals during binocular rivalry. Auditory looming/receding signals may influence the dominance times of their congruent and incongruent visual percepts via genuine multisensory and higher order attentional mechanisms at multiple levels of the cortical hierarchy

Associations of LV Hypertrophy With Prevalent and Incident Valve Calcification Multi-Ethnic Study of Atherosclerosis

ObjectivesThe aim of this study was to evaluate the relationship between percentage of predicted left ventricular mass (%PredLVM) and valve calcification in the MESA (Multi-Ethnic Study of Atherosclerosis) study.BackgroundCardiac valve calcification has been associated with left ventricular hypertrophy (LVH), which portends cardiovascular events. However, this relationship and its mediators are poorly understood.MethodsThe MESA study is a longitudinal cohort study of men and women 45 to 84 years of age without clinical cardiovascular disease in whom serial cardiac magnetic resonance and computed tomography imaging were performed. The relationships between baseline %PredLVM and the prevalence, severity, and incidence of aortic valve (AVC) and mitral annulus calcification (MAC) were determined by regression modeling.ResultsPrevalent AVC was observed in 630, and MAC was observed in 442 of 5,042 subjects (median 55.9 and 71.1 Agatston units, respectively). After adjustment for age, sex, body mass index (BMI), ethnicity, socioeconomic status, physical activity, diabetes, cholesterol levels, blood pressure, smoking, kidney function, serum lipids, and antihypertensive and statin medications, %PredLVM was associated with prevalent AVC (odds ratio [OR]: 1.18/SD increase in %PredLVM [95% confidence interval (CI): 1.08 to 1.30]; p = 0.0004) and MAC (OR: 1.18 [95% CI: 1.06 to 1.32]; p = 0.002). Similarly, %PredLVM was associated with increased severity of prevalent AVC (risk difference = 0.26 [95% CI: 0.15 to 0.38]; p < 0.0001) and MAC (risk difference = 0.20 [95% CI: 0.03 to 0.37]; p = 0.02). During follow-up (mean 2.4 ± 0.9 years), 153 subjects (4%) developed AVC, and 198 (5%) developed MAC. The %PredLVM was associated with incident AVC (OR: 1.24 [95% CI: 1.04 to 1.47]; p = 0.02) and MAC (OR: 1.18 [95% CI: 1.01 to 1.40]; p = 0.04). Further adjustment for inflammatory markers and coronary artery calcification did not attenuate these associations. Specifically, concentric LVH most strongly predicted incident valve calcification.ConclusionsWithin the MESA cohort, LVH was associated with prevalence, severity, and incidence of valve calcification independent of hypertension and other identified confounders