Aug 28, 2013
Sentiment in New York City: A High Resolution Spatial and Temporal View
Karla Z. Bertrand, Maya Bialik, Kawandeep Virdee, Andreas Gros, Yaneer Bar-Yam
http://arxiv.org/abs/1308.5010v1 (link to PDF full text)
Measuring public sentiment is a key task for researchers and policymakers alike. The explosion of available social media data allows for a more time-sensitive and geographically specific analysis than ever before. In this paper we analyze data from the micro-blogging site Twitter and generate a sentiment map of New York City. We develop a classifier specifically tuned for 140-character Twitter messages, or tweets, using key words, phrases and emoticons to determine the mood of each tweet. This method, combined with geotagging provided by users, enables us to gauge public sentiment on extremely fine-grained spatial and temporal scales. We find that public mood is generally highest in public parks and lowest at transportation hubs, and locate other areas of strong sentiment such as cemeteries, medical centers, a jail, and a sewage facility. Sentiment progressively improves with proximity to Times Square. Periodic patterns of sentiment fluctuate on both a daily and a weekly scale: more positive tweets are posted on weekends than on weekdays, with a daily peak in sentiment around midnight and a nadir between 9:00 a.m. and noon.
Aug 07, 2013
A recent introductory talk on the problem that consciousness and qualia presents to physicalism by Frank C. Jackson.
Welcome to wonderland: the influence of the size and shape of a virtual hand on the perceived size and shape of virtual objects
Welcome to wonderland: the influence of the size and shape of a virtual hand on the perceived size and shape of virtual objects.
PLoS One. 2013;8(7):e68594
Authors: Linkenauger SA, Leyrer M, Bülthoff HH, Mohler BJ
The notion of body-based scaling suggests that our body and its action capabilities are used to scale the spatial layout of the environment. Here we present four studies supporting this perspective by showing that the hand acts as a metric which individuals use to scale the apparent sizes of objects in the environment. However to test this, one must be able to manipulate the size and/or dimensions of the perceiver's hand which is difficult in the real world due to impliability of hand dimensions. To overcome this limitation, we used virtual reality to manipulate dimensions of participants' fully-tracked, virtual hands to investigate its influence on the perceived size and shape of virtual objects. In a series of experiments, using several measures, we show that individuals' estimations of the sizes of virtual objects differ depending on the size of their virtual hand in the direction consistent with the body-based scaling hypothesis. Additionally, we found that these effects were specific to participants' virtual hands rather than another avatar's hands or a salient familiar-sized object. While these studies provide support for a body-based approach to the scaling of the spatial layout, they also demonstrate the influence of virtual bodies on perception of virtual environments.
Using avatars to model weight loss behaviors: participant attitudes and technology development.
J Diabetes Sci Technol. 2013;7(4):1057-65
Authors: Napolitano MA, Hayes S, Russo G, Muresu D, Giordano A, Foster GD
BACKGROUND: Virtual reality and other avatar-based technologies are potential methods for demonstrating and modeling weight loss behaviors. This study examined avatar-based technology as a tool for modeling weight loss behaviors. METHODS: This study consisted of two phases: (1) an online survey to obtain feedback about using avatars for modeling weight loss behaviors and (2) technology development and usability testing to create an avatar-based technology program for modeling weight loss behaviors. RESULTS: Results of phase 1 (n = 128) revealed that interest was high, with 88.3% stating that they would participate in a program that used an avatar to help practice weight loss skills in a virtual environment. In phase 2, avatars and modules to model weight loss skills were developed. Eight women were recruited to participate in a 4-week usability test, with 100% reporting they would recommend the program and that it influenced their diet/exercise behavior. Most women (87.5%) indicated that the virtual models were helpful. After 4 weeks, average weight loss was 1.6 kg (standard deviation = 1.7). CONCLUSIONS: This investigation revealed a high level of interest in an avatar-based program, with formative work indicating promise. Given the high costs associated with in vivo exposure and practice, this study demonstrates the potential use of avatar-based technology as a tool for modeling weight loss behaviors.Abstract
What Color is My Arm? Changes in Skin Color of an Embodied Virtual Arm Modulates Pain Threshold.
Front Hum Neurosci. 2013;7:438
Authors: Martini M, Perez-Marcos D, Sanchez-Vives MV
It has been demonstrated that visual inputs can modulate pain. However, the influence of skin color on pain perception is unknown. Red skin is associated to inflamed, hot and more sensitive skin, while blue is associated to cyanotic, cold skin. We aimed to test whether the color of the skin would alter the heat pain threshold. To this end, we used an immersive virtual environment where we induced embodiment of a virtual arm that was co-located with the real one and seen from a first-person perspective. Virtual reality allowed us to dynamically modify the color of the skin of the virtual arm. In order to test pain threshold, increasing ramps of heat stimulation applied on the participants' arm were delivered concomitantly with the gradual intensification of different colors on the embodied avatar's arm. We found that a reddened arm significantly decreased the pain threshold compared with normal and bluish skin. This effect was specific when red was seen on the arm, while seeing red in a spot outside the arm did not decrease pain threshold. These results demonstrate an influence of skin color on pain perception. This top-down modulation of pain through visual input suggests a potential use of embodied virtual bodies for pain therapy.
When it comes to some of the health hazards of light at night, a new study suggests that the color of the light can make a big difference.
Read full story on Science Daily
In a list of "Disturbing Phubbing Stats" on their website, of note:
-- If phubbing were a plague it would decimate six Chinas
-- 97% of people claim their food tasted worse while being a victim of phubbing
-- 92% of repeat phubbers go on to become politicians
So it's really just a joke site? Well, a joke site with a serious message about our growing estrangement from our fellow human beings. But mostly a joke site, yes.
Read full article.
Re-blogged from Medgadget
Google Glass may have been developed to transform the way people see the world around them, but thanks to Dapper Vision’s OpenGlass Project, one doesn’t even need to be able to see to experience the Silicon Valley tech giant’s new spectacles.
Harnessing the power of Google Glass’ built-in camera, the cloud, and the “hive-mind”, visually impaired users will be able to know what’s in front of them. The system consists of two components: Question-Answer sends pictures taken by the user and uploads them to Amazon’s Mechanical Turk and Twitter for the public to help identify, and Memento takes video from Glass and uses image matching to identify objects from a database created with the help of seeing users. Information about what the Glass wearer “sees” is read aloud to the user via bone conduction speakers.
Here’s a video that explains more about how it all works:
Pupil responses allow communication in locked-in syndrome patients.
Josef Stoll et al., Current Biology, Volume 23, Issue 15, R647-R648, 5 August 2013
For patients with severe motor disabilities, a robust means of communication is a crucial factor for their well-being. We report here that pupil size measured by a bedside camera can be used to communicate with patients with locked-in syndrome. With the same protocol we demonstrate command-following for a patient in a minimally conscious state, suggesting its potential as a diagnostic tool for patients whose state of consciousness is in question. Importantly, neither training nor individual adjustment of our system’s decoding parameters were required for successful decoding of patients’ responses.
Paper full text PDF
Image credit: Flickr user Beth77
German test of the controllability of motor imagery in older adults.
Z Gerontol Geriatr. 2013 Aug 3;
Authors: Schott N
Abstract. After a person is instructed to imagine a certain movement, no possibility exists to control whether the person is doing what they are asked for. The purpose of this study was to validate the German Test of the Controllability of Motor Imagery ("Tests zur Kontrollierbarkeit von Bewegungsvorstellungen" TKBV). A total sample of 102 men [mean 55.6, standard deviation (SD) 25.1] and 93 women (mean 59.2, SD 24.0) ranging in age from 18-88 years completed the TKBV. Two conditions were performed: a recognition (REC) and a regeneration (REG) test. In both conditions the participants had to perform the six consecutive instructions. They were asked to imagine the posture of their own body. Subjects had to move only one body part (head, arms, legs, trunk) per instruction. On the regeneration test the participants had to actually produce the final position. On the recognition test, they were required to select the one picture among five pictures, which fit the imagery they have. Explorative factor analysis showed the proposed two-dimensional solution: (1) the ability to control their body scheme, and (2) the ability to transform a visual imagery. Cronbach's α of the two dimensions of the TKBV were 0.89 and 0.73, respectively. The scales correlate low with convergent measures assessing mental chronometry (Timed-Up-and-Go test, rREG = - 0.33, rREC = - 0.31), and the vividness of motor imagery (MIQvis, rREG = 0.14, rREC = 0.14; MIQkin, rREG = 0.11, rREC = 0.13). Criterion validity of the TKBV was established by statistically significant correlations between the subscales, the Corsi block tapping test (BTT, rREG = 0.45, rREC = 0.38) and with physical activity (rREG = 0.50, rREC = 0.36). The TKBV is a valid instrument to assess motor imagery. Thus, it is an important and helpful tool in the neurologic and orthopedic rehabilitation.
Detecting delay in visual feedback of an action as a monitor of self recognition.
Exp Brain Res. 2012 Oct;222(4):389-97
Authors: Hoover AE, Harris LR
Abstract. How do we distinguish "self" from "other"? The correlation between willing an action and seeing it occur is an important cue. We exploited the fact that this correlation needs to occur within a restricted temporal window in order to obtain a quantitative assessment of when a body part is identified as "self". We measured the threshold and sensitivity (d') for detecting a delay between movements of the finger (of both the dominant and non-dominant hands) and visual feedback as seen from four visual perspectives (the natural view, and mirror-reversed and/or inverted views). Each trial consisted of one presentation with minimum delay and another with a delay of between 33 and 150 ms. Participants indicated which presentation contained the delayed view. We varied the amount of efference copy available for this task by comparing performances for discrete movements and continuous movements. Discrete movements are associated with a stronger efference copy. Sensitivity to detect asynchrony between visual and proprioceptive information was significantly higher when movements were viewed from a "plausible" self perspective compared with when the view was reversed or inverted. Further, we found differences in performance between dominant and non-dominant hand finger movements across the continuous and single movements. Performance varied with the viewpoint from which the visual feedback was presented and on the efferent component such that optimal performance was obtained when the presentation was in the normal natural orientation and clear efferent information was available. Variations in sensitivity to visual/non-visual temporal incongruence with the viewpoint in which a movement is seen may help determine the arrangement of the underlying visual representation of the body.
Re-blogged from New Scientist
Glass could soon be used for more than just snapping pics of your lunchtime sandwich. A new game will connect Glass wearers to a virtual ant colony vying for prizes by solving real-world problems that vex traditional crowdsourcing efforts.
Crowdsourcing is most famous for collaborative projects like Wikipedia and "games with a purpose" like FoldIt, which turns the calculations involved in protein folding into an online game. All require users to log in to a specific website on their PC.
The pair have designed a game called Swarm! that puts a Glass wearer in the role of an ant in a colony. Similar to the pheromone trails laid down by ants, players leave virtual trails on a map as they move about. These behave like real ant trails, fading away with time unless reinforced by other people travelling the same route. Such augmented reality games already exist – Google's Ingress, for one – but in Swarm! the tasks have real-world applications.
Swarm! players seek out virtual resources to benefit their colony, such as food, and must avoid crossing the trails of other colony members. They can also monopolise a resource pool by taking photos of its real-world location.
To gain further resources for their colony, players can carry out real-world tasks. For example, if the developers wanted to create a map of the locations of every power outlet in an airport, they could reward players with virtual food for every photo of a socket they took. The photos and location data recorded by Glass could then be used to generate a map that anyone could use. Such problems can only be solved by people out in the physical world, yet the economic incentives aren't strong enough for, say, the airport owner to provide such a map.
Estrada and Lawhead hope that by turning tasks such as these into games, Swarm! will capture the group intelligence ant colonies exhibit when they find the most efficient paths between food sources and the home nest.
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7-9 January 2014, Lisbon, Portugal
Physiological data in its different dimensions, either bioelectrical, biomechanical, biochemical or biophysical, and collected through specialized biomedical devices, video and image capture or other sources, is opening new boundaries in the field of human-computer interaction into what can be defined as Physiological Computing. PhyCS is the annual meeting of the physiological interaction and computing community, and serves as the main international forum for engineers, computer scientists and health professionals, interested in outstanding research and development that bridges the gap between physiological data handling and human-computer interaction.
Regular Paper Submission Extension: September 15, 2013
Regular Paper Authors Notification: October 23, 2013
Regular Paper Camera Ready and Registration: November 5, 2013