Cue Integration in Categorical Tasks: Insights from Audio-Visual Speech Perception

Previous cue integration studies have examined continuous perceptual dimensions (e.g., size) and have shown that human cue integration is well described by a normative model in which cues are weighted in proportion to their sensory reliability, as estimated from single-cue performance. However, this normative model may not be applicable to categorical perceptual dimensions (e.g., phonemes). In tasks defined over categorical perceptual dimensions, optimal cue weights should depend not only on the sensory variance affecting the perception of each cue but also on the environmental variance inherent in each task-relevant category. Here, we present a computational and experimental investigation of cue integration in a categorical audio-visual (articulatory) speech perception task. Our results show that human performance during audio-visual phonemic labeling is qualitatively consistent with the behavior of a Bayes-optimal observer. Specifically, we show that the participants in our task are sensitive, on a trial-by-trial basis, to the sensory uncertainty associated with the auditory and visual cues, during phonemic categorization. In addition, we show that while sensory uncertainty is a significant factor in determining cue weights, it is not the only one and participants' performance is consistent with an optimal model in which environmental, within category variability also plays a role in determining cue weights. Furthermore, we show that in our task, the sensory variability affecting the visual modality during cue-combination is not well estimated from single-cue performance, but can be estimated from multi-cue performance. The findings and computational principles described here represent a principled first step towards characterizing the mechanisms underlying human cue integration in categorical tasks

The role of a best practice alert in the electronic medical record in reducing repetitive lab tests

Harini Bejjanki,1 Lazarus K Mramba,2 Stacy G Beal,3 Nila Radhakrishnan,1 Rohit Bishnoi,1 Chintan Shah,1 Nikhil Agrawal,4 Neil Harris,3 Robert Leverence,1 Kenneth Rand3 1Division of Hospital Medicine, Department of Medicine, University of Florida, Gainesville, FL, USA; 2Statistics, Department of Internal Medicine, University of Florida, Gainesville, FL, USA; 3Department of Pathology, Immunology, & Laboratory Medicine, College of Medicine, University of Florida, Gainesville, FL, USA; 4Department of Nephrology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA Background: The recommendations of the American Board of Internal Medicine Foundation’s “Choosing Wisely®” initiative recognize the importance of improving the appropriateness of testing behavior and reducing the number of duplicate laboratory tests.Objective: To assess the effectiveness of an electronic medical record Best Practice Alert (BPA or “pop up”) intervention aimed at reducing duplicate laboratory tests and hospital costs.Design: Comparison of the number of duplicated laboratory tests performed on inpatients before and after the intervention.Setting: University of Florida Health Shands Hospital, Gainesville, FL, USA, during 2014–2017.Intervention: The electronic medical record intervention was a BPA pop-up alert that informed the ordering physician if a recent identical order already existed along with the “ordering time”, “collecting time”, “resulting time”, and the result itself.Main outcome measures: Percentage change in the number of inpatient duplicate orders of selected clinical biochemistry tests and cost savings from reduction of the duplicates. Student’s t-test and beta-binomial models were used to analyze the data.Results: Results from the beta-binomial model indicated that the intervention reduced the overall duplicates by 18% (OR=0.82, standard error=0.016, P-value<0.000). Percent reductions in 9 of the 17 tests were statistically significant: serum hemoglobin A1C level, vitamin B12, serum erythrocyte sedimentation rate, serum folate, serum iron, lipid panel, respiratory viral panel, serum thyroid stimulating hormone level, and Vitamin D. Additionally, important cost savings were realized from the reduction of duplicates for each lab test (with the exception of CRP) with an estimated overall savings of $72,543 over 17 months in the post-intervention period.Conclusions: The present study included all hospital inpatients and covered 17 clinical laboratory tests. This rather simple and low-cost intervention resulted in significant reductions in percentage duplicates of several tests and resulted in cost savings. The study also highlights the role of hospitalists in quality improvement. Keywords: laboratory, testing, health care, cost

Near-optimal integration of facial form and motion

Abstract Human perception consists of the continuous integration of sensory cues pertaining to the same object. While it has been fairly well shown that humans use an optimal strategy when integrating low-level cues proportional to their relative reliability, the integration processes underlying high-level perception are much less understood. Here we investigate cue integration in a complex high-level perceptual system, the human face processing system. We tested cue integration of facial form and motion in an identity categorization task and found that an optimal model could successfully predict subjects’ identity choices. Our results suggest that optimal cue integration may be implemented across different levels of the visual processing hierarchy