Presence in Visual Mental Imagery

‘Presence’, the sense of being inside a virtual environment evoked with the help of computer mediation, has come to be a subject well explored in the field of virtual reality. Studies on mental imagery confirm that we can intuitively evoke objects and spaces in our minds and interact with them temporally. We believe that a sense of presence could be experienced in such self-evoked reality as well. This paper explores the experience of presence in visual mental imagery. We studied verbal expressions, physical movements and gestures, exhibited during mental imagery experiences in two scenarios - a guiding task and a mental walk exercise. A ‘protocol analysis’ was performed followed by analysis of time taken and mapping of physical movements. The results evidently point to this spatio-temporal phenomenon of experiencing presence. Furthermore, we present a comparative review on the sense of presence experienced during mental imagery and virtual reality.IIT-ParisTech mobility programm

Quantum Dot Targeting with Lipoic Acid Ligase and HaloTag for Single-Molecule Imaging on Living Cells

We present a methodology for targeting quantum dots to specific proteins on living cells in two steps. In the first step, Escherichia coli lipoic acid ligase (LplA) site-specifically attaches 10-bromodecanoic acid onto a 13 amino acid recognition sequence that is genetically fused to a protein of interest. In the second step, quantum dots derivatized with HaloTag, a modified haloalkane dehalogenase, react with the ligated bromodecanoic acid to form a covalent adduct. We found this targeting method to be specific, fast, and fully orthogonal to a previously reported and analogous quantum dot targeting method using E. coli biotin ligase and streptavidin. We used these two methods in combination for two-color quantum dot visualization of different proteins expressed on the same cell or on neighboring cells. Both methods were also used to track single molecules of neurexin, a synaptic adhesion protein, to measure its lateral diffusion in the presence of neuroligin, its trans-synaptic adhesion partner.National Institutes of Health (U.S.) (R01 GM072670)Camille & Henry Dreyfus FoundationMassachusetts Institute of Technology. Computational and Systems Biology Program. MIT-Merck Postdoctoral Fellowshi

A systematic review of protocol studies on conceptual design cognition

This paper reports the first systematic review and synthesis of protocol studies on conceptual design cognition. 47 protocol studies from the domains of architectural design, engineering design, and product de-sign engineering were reviewed towards answering the following re-search question: What is our current understanding of the cognitive processes involved in conceptual design tasks carried out by individual designers? Studies were found to reflect three viewpoints on the cognitive nature of designing, namely: design as search; design as ex-ploration; and design activities. Synthesising the findings of individual studies yielded a classification of cognitive processes involved in con-ceptual design tasks, described in different terms across different viewpoints. Towards a common terminology, these processes are posi-tioned within the cognitive psychology literature, revealing seven basic types of process that appear to be fundamental to designing across all viewpoints: memory (working and long term); visual perception; men-tal imagery; attention; semantic association; cognitive control; and higher-order processes, e.g. analysis and reasoning. The development of common cognitive models of conceptual design, grounded in a sci-entifically rigorous understanding of design cognition, is identified as an avenue for future research

Presence in Visual Mental Imagery

‘Presence’, the sense of being inside a virtual environment evoked with the help of computer mediation, has come to be a subject well explored in the field of virtual reality. Studies on mental imagery confirm that we can intuitively evoke objects and spaces in our minds and interact with them temporally. We believe that a sense of presence could be experienced in such self-evoked reality as well. This paper explores the experience of presence in visual mental imagery. We studied verbal expressions, physical movements and gestures, exhibited during mental imagery experiences in two scenarios - a guiding task and a mental walk exercise. A ‘protocol analysis’ was performed followed by analysis of time taken and mapping of physical movements. The results evidently point to this spatio-temporal phenomenon of experiencing presence. Furthermore, we present a comparative review on the sense of presence experienced during mental imagery and virtual reality.International audience‘Presence’, the sense of being inside a virtual environment evoked with the help of computer mediation, has come to be a subject well explored in the field of virtual reality. Studies on mental imagery confirm that we can intuitively evoke objects and spaces in our minds and interact with them temporally. We believe that a sense of presence could be experienced in such self-evoked reality as well. This paper explores the experience of presence in visual mental imagery. We studied verbal expressions, physical movements and gestures, exhibited during mental imagery experiences in two scenarios - a guiding task and a mental walk exercise. A ‘protocol analysis’ was performed followed by analysis of time taken and mapping of physical movements. The results evidently point to this spatio-temporal phenomenon of experiencing presence. Furthermore, we present a comparative review on the sense of presence experienced during mental imagery and virtual reality

Imaging proteins in live mammalian cells with biotin ligase and monovalent streptavidin.

This protocol describes a simple and efficient way to label specific cell surface proteins with biophysical probes on mammalian cells. Cell surface proteins tagged with a 15-amino acid peptide are biotinylated by Escherichia coli biotin ligase (BirA), whereas endogenous proteins are not modified. The biotin group then allows sensitive and stable binding by streptavidin conjugates. This protocol describes the optimal use of BirA and streptavidin for site-specific labeling and also how to produce BirA and monovalent streptavidin. Streptavidin is tetravalent and the cross-linking of biotinylated targets disrupts many of streptavidin's applications. Monovalent streptavidin has only a single functional biotin-binding site, but retains the femtomolar affinity, low off-rate and high thermostability of wild-type streptavidin. Site-specific biotinylation and streptavidin staining take only a few minutes, while expression of BirA takes 4 d and expression of monovalent streptavidin takes 8 d