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It is clear that people can learn a new sensory skill – a new way of mapping sensory inputs onto world states. It remains unclear how flexibly a new sensory skill can become embedded in multisensory perception and decision-making. To address this, we trained typically-sighted participants (N=12) to use a new echo-like auditory cue to distance in a virtual world, together with a noisy visual cue. Using model-based analyses, we tested for key markers of efficient multisensory perception and decision-making with the new skill. We found that twelve of fourteen participants learned to judge distance using the novel auditory cue. Their use of this new sensory skill showed three key features: (1) it enhanced the speed of timed decisions; (2) it largely resisted interference from a simultaneous digit span task; and (3) it integrated with vision in a Bayes-like manner to improve precision. We also show some limits following this relatively short training: precision benefits were lower than the Bayesoptimal prediction, and there was no forced fusion of signals. We conclude that people already embed new sensory skills in flexible multisensory perception and decision-making after a short training period. A key application of these insights is to the development of sensory augmentation systems that can enhance human perceptual abilities in novel ways. The limitations we reveal (sub-optimality, lack of fusion) provide a foundation for further investigations of the limits of these abilities and their brain basis.

A parabolic cylinder is an invariant, non-recurrent Fatou component Ω of an automorphism F of C2 satisfying: (1) The closure of the ω-limit set of F on Ω contains an isolated fixed point, (2) there exists a univalent map Φ from Ω into C2 conjugating F to the translation (z, w) ↦ (z+ 1 , w) , and (3) every limit map of { F∘ n} on Ω has one-dimensional image. In this paper, we prove the existence of parabolic cylinders for an explicit class of maps, and show that examples in this class can be constructed as compositions of shears and overshears.

Humans can learn to use acoustic echoes to detect and classify objects. Echolocators typically use tongue clicks to induce these echoes, and there is some evidence that higher spectral frequency content of an echolocator’s tongue click is associated with better echolocation performance. This may be explained by the intensity of the echoes. The current study tested experimentally (a) if emissions with higher spectral frequencies lead to better performance for target detection, and (b) if this is mediated by echo intensity. Participants listened to sound recordings that contained an emission and sometimes an echo from an object. The peak spectral frequency of the emission was varied between 3.5 and 4.5 kHz. Participants judged whether they heard the object in these recordings and did the same under conditions in which the intensity of the echoes had been digitally equated. Participants performed better using emissions with higher spectral frequencies, but this advantage was eliminated when the intensity of the echoes was equated. These results demonstrate that emissions with higher spectral frequencies can benefit echolocation performance in conditions where they lead to an increase in echo intensity. The findings suggest that people who train to echolocate should be instructed to make emissions (e.g. mouth clicks) with higher spectral frequency content.

To evaluate the effects on depressive mood of withdrawal of antihypertensive medication, we conducted a randomized, multi-center study with clinical centers at the Albert Einstein College of Medicine, Bronx, NY, University of Alabama School of Medicine, Birmingham, and the University of Mississippi School of Medicine in Jackson. Patients were formerly active participants in the Hypertension Detection and Follow-Up Program (HDFP) whose blood pressure was controlled with drugs for a period of 5 years. Of 496 patients, 431 had both baseline and "1-year" mood scores. Patients, stratified by obesity, were randomized to one of three groups: continue the HDFP medication; discontinue medication with no dietary intervention, or with sodium restriction and potassium increase; or, for those overweight, to a weight reduction intervention. Depression was assessed using the CES-D scale (Center for Epidemiological Studies--Depressed Mood), administered at baseline and again approximately 1 year after randomization. Of the seven treatment groups, only those who continued their HDFP medication showed significant improvement in mood from baseline. The overweight continue-medication group showed significantly greater improvement compared to the no-drugs, no-diet intervention groups, and to the overweight sodium-restriction group. Patients who had their blood pressure successfully controlled with weight reduction had a significant improvement in mood from 11.0 scale points to 8.0, P = .006. Comparisons between those withdrawn from diuretic alone and those withdrawn from both diuretic plus reserpine were inconclusive. Dietary Intervention Study of Hypertension (DISH) shows no evidence that continued use of chlorthalidone has a negative impact on quality of life, while our results concerning reserpine were inconclusive.(ABSTRACT TRUNCATED AT 250 WORDS)