Mental Imagery Induces Cross-Modal Sensory Plasticity and Changes Future Auditory Perception

Can what we imagine in our minds change how we perceive the world in the future? A continuous process of multisensory integration and recalibration is responsible for maintaining a correspondence between the senses (e.g., vision, touch, audition) and, ultimately, a stable and coherent perception of our environment. This process depends on the plasticity of our sensory systems. The so-called ventriloquism aftereffect—a shift in the perceived localization of sounds presented alone after repeated exposure to spatially mismatched auditory and visual stimuli—is a clear example of this type of plasticity in the audiovisual domain. In a series of six studies with 24 participants each, we investigated an imagery-induced ventriloquism aftereffect in which imagining a visual stimulus elicits the same frequency-specific auditory aftereffect as actually seeing one. These results demonstrate that mental imagery can recalibrate the senses and induce the same cross-modal sensory plasticity as real sensory stimuli

Measuring Underemployment at the County Level

As labor markets tightened in the last half of the nineties, economic development and community leaders sought to identify more locally available workers than were indicated by published statistics. Using results from commissioned surveys, they pointed to large numbers of part-time workers who desired full-time work, and to full-time workers who were qualified for better jobs. These statistics were often used to negate low official unemployment rates that deterred firms, concerned by the ostensible shortage of workers, from locating in their counties. We have conducted a larger, statewide, survey of underemployment and linked it to the detailed demographic and labor force data from the 2000 Census. We used the results to identify variations in the number and type of underemployed persons around the state, with emphasis on the differences between urbanized and rural areas. Over a quarter of full-time workers reported underemployment, including a third of workers in exurban counties. However, forty to fifty percent of underemployment is reportedly by choice, with the highest rates in the small urban and exurban regions. Of those that are not underemployed by choice, over ninety percent of respondents in some regions cited lack of job opportunities. We find that between fourteen and forty percent of part-time workers prefer full-time work, with the highest rates in rural Appalachian counties. We provide some of the reasons underemployed people cite as constraints to better employment. Also, we used the survey results and the recent Census information to predict the number and type of underemployed persons in each county. The model can be used to update predictions as new local demographic and labor force estimates are released annually from the Census Bureau’s forthcoming American Community Surveys

Where imagination meets sensation : mental imagery, perception and multisensory Integration

What happens if we imagine seeing something while we are listening to something? Will it change what we hear? What happens if we imagine hearing something while we are looking at something? Will it change what we see? In everyday perception, our brains integrate the information provided to us by our different senses in order to form a coherent perception of the world around us in a process referred to as multisensory integration. However, sometimes the information provided to our senses arises from within, as is the case when we imagine a sensory stimulus; for example, when you picture in your mind the face of a loved one, or imagine how they sound when they say your name. The term mental imagery is used to refer to these willed simulations of sensory stimuli in our minds. Empirical research on mental imagery has demonstrated that there is a great deal of similarity in how we consciously experience, and in how our brains process the sensory stimuli we imagine and the sensory stimuli we perceive from the external world. However, whether our brains integrate stimuli that are imagined in one sense and perceived in the other has never before been explored. The main aim of this thesis was to investigate this possibility. There were two main goals of the work comprising this thesis. First, to examine whether mental imagery is integrated with incoming sensory stimuli from a different sensory modality to change perception, and second, to examine the neural correlates of these mental imageryinduced changes in perception. Multisensory illusions have come to be a hallmark of multisensory integration as they are an easy and demonstrable way of measuring the integration of cross-modal sensory stimuli. Here, we have made use of classic multisensory illusions, and adapted them to investigate whether mental imagery in one sensory modality can integrate with veridical sensation in another sensory modality to produced fused multisensory percepts. We also used functional magnetic resonance imaging (fMRI) to examine whether brain areas related to multisensory integration of real stimuli were involved in multisensory integration of real and imagined stimuli. By supplanting a real sensory stimulus with an imagined one in three different classic multisensory illusions, we found that imagined sensory stimuli were integrated with real sensory stimuli from a different sensory modality to change perception. Moreover, we found that these imagery-induced multisensory illusions followed the same spatial and temporal rules as classic multisensory illusions (Study I), as well as the unity-assumption rule of multisensory integration (Study II). Furthermore, we found that the neural correlates of a mental imagery-induced multisensory illusion were closely related to those known to be involved in integration of real multisensory stimuli (Study III). Lastly, consistent with what is known about adaptation to real multisensory stimuli, we found that repeated pairings of imagined and real stimuli from different sensory modalities lead to changes in future perception of the latter (Study IV). Together, these findings suggest that, indeed, what we imagine hearing can change what we see, and what we imagine seeing can change what we hear, affording mental imagery a larger role in multisensory perception than has ever before been considered

Consecutive Case Series of Melanoma Sentinel Node Biopsy for Lymphoseek Compared to Sulfur Colloids

Introduction: Sentinel lymph node biopsy (SLNB) is an important adjunct in the staging of patients with melanoma. Preoperative lymphoscintigraphy (LS) with radiolabeled isotopes is essential to localize sentinel nodes for removal. Our study compared the effectiveness of Lymphoseek to standard sulfur colloids (SC) in patients with melanoma undergoing SLNB. Methods: We queried our IRB-approved melanoma database to identify 370 consecutive patients who underwent SLNB from 2012-2016 with at least one year of follow up. There were 185 patients in each group. Data points included characteristics of the primary melanoma lymphoscintigraphy, and SLNB. Student’s t-test and Chi-Square were used to analyze the data with a p-value of \u3c0.05 being considered significant. Results: Patients were equally matched in regard to age, sex, and primary characteristics of their melanoma. In comparison to SC, Lymphoseek required lower radiation dosages (p\u3c0.001), shorter mapping times (p=0.008), and decreased number of sentinel nodes removed (p=0.03). There was no difference in the number of patients with positive nodes (p=0.5). Additionally, there were no statistical differences between the two radioactive tracers in regard to the number of patients with false negative SLNB. Conclusion: Lymphoseek has the potential to decrease radioactivity and mapping time in patients who need SLNB. With a decrease in the number of nodes removed without loss of sensitivity, there is a potential to avoid unnecessary node removal and thus complications such as lymphedema. Longer follow-up will help to determine if there is any increase in false negative rates despite fewer nodes removed

The uncanny valley of haptics

During teleoperation and virtual reality experiences, enhanced haptic feedback incongruent with other sensory cues can reduce subjective realism, producing an uncanny valley of haptics

The impact of first-person avatar customization on embodiment in immersive virtual reality

In virtual reality (VR), users can embody a wide variety of avatars, from digital replicas of themselves through diverse human body styles and appearances to non-humanoid representations. Although choosing a body to inhabit is part of what makes VR such an engaging experience, various studies have shown how embodiment may change the way we perceive ourselves and others both inside and outside VR. In our study, we explored whether first-person versus third-person avatar customization would lead to changes in embodiment. Furthermore, participants were embodied in larger-sized avatars based on the hypothesis that embodiment would lead to a change in implicit bias toward larger-sized people. Our results show that third-person avatar customization led to a decrease in the perceived embodiment of the larger-sized avatar and that, on the contrary, higher embodiment was associated with a reduction in implicit biases toward larger-sized people in the first-person avatar customization mode. These findings suggest that third-person avatar customization leads to reduced feelings of embodiment, while first-person avatar customization may support more radical body changes

Biomineralization of PbS and PbS-CdS core-shell nanocrystals and their application in quantum dot sensitized solar cells

Biomineralization utilizes biological systems to synthesize functional inorganic materials for application in diverse fields. In the current work, we enable biomineralization of quantum confined PbS and PbS–CdS core–shell nanocrystals and demonstrate their application in quantum dot sensitized solar cells (QDSSCs). An engineered strain of Stenotrophomonas maltophilia is utilized to generate a cystathionine γ-lyase that is active for the biomineralization of metal sulfide nanocrystals from a buffered aqueous solution of metal salts and L-cysteine. In the presence of lead acetate, this enzymatic route generates rock salt structured PbS nanocrystals. Controlling the growth conditions yields ∼4 nm PbS crystals with absorption and photoluminescence peaks at 910 nm and 1080 nm, respectively, consistent with the expected strong quantum confinement of PbS at this size. Quantum yields (QY) of the biomineralized PbS quantum dots, determined after phase transfer to the organic phase, range between 16 and 45%. These are the highest reported QY values for any biomineralized quantum dot materials to date and are comparable with QYs reported for chemically synthesized materials. Subsequent exposure to cadmium acetate results in the biomineralization of a thin CdS shell on the PbS core with a resultant blue-shift in optical properties. The photoluminescence peak shifts to 980 nm, consistent with the expected decrease in band gap energy of a PbS–CdS core–shell heterostructured quantum dot. HAADF-STEM imaging confirms the crystalline structure and size of the particles with complimentary XEDS analysis confirming the presence of Cd, Pb, and S in individual nanocrystals. Integration of these QDs into QDSSCs yields open circuit potentials of 0.43 V and 0.59 V for PbS and PbS–CdS, respectively, consistent with expectations for these materials and previously reported values for chemically synthesized QDs

Falling Pitch Imitating Doppler Shift Facilitates Detection of Visual Motion in The Extreme-Periphery

Previous studies demonstrated that concurrent auditory stimuli can bias visual motion perception in the periphery more than in the fovea (e.g., Takeshima & Gyoba, 2013), and auditory becomes crucial when reliability of vision is reduced (e.g., Schmiedchen et al., 2012). We investigated if auditory affects detecting extreme-peripheral visual motion from behind, which is possibly one of the most salient situations since visual ambiguity is very high and detecting such motion can be ecologically critical to survive. In the experiment, a sequence of three 204 ms dots (255 ms SOA) was presented in the extreme-periphery (individually set by the largest eccentricity with 75% detection); each dot was presented at 3 adjacent locations with 2° distance so as to have apparent motion forward, or at the same location. As auditory stimuli, we employed concurrent beep with falling pitch, which roughly imitated Doppler pitch shift for passing-by object. We employed concurrent beep with rising pitch as a control, in addition to another no sound control. The results showed the concurrent beep with falling pitch increased the hit rate for motion detection, relative to that with no sound and rising pitch beep. Underlying mechanism was discussed with signal detection analysis