46,424 research outputs found
Assentication: User Deauthentication and Lunchtime Attack Mitigation with Seated Posture Biometric
Biometric techniques are often used as an extra security factor in
authenticating human users. Numerous biometrics have been proposed and
evaluated, each with its own set of benefits and pitfalls. Static biometrics
(such as fingerprints) are geared for discrete operation, to identify users,
which typically involves some user burden. Meanwhile, behavioral biometrics
(such as keystroke dynamics) are well suited for continuous, and sometimes more
unobtrusive, operation. One important application domain for biometrics is
deauthentication, a means of quickly detecting absence of a previously
authenticated user and immediately terminating that user's active secure
sessions. Deauthentication is crucial for mitigating so called Lunchtime
Attacks, whereby an insider adversary takes over (before any inactivity timeout
kicks in) authenticated state of a careless user who walks away from her
computer. Motivated primarily by the need for an unobtrusive and continuous
biometric to support effective deauthentication, we introduce PoPa, a new
hybrid biometric based on a human user's seated posture pattern. PoPa captures
a unique combination of physiological and behavioral traits. We describe a low
cost fully functioning prototype that involves an office chair instrumented
with 16 tiny pressure sensors. We also explore (via user experiments) how PoPa
can be used in a typical workplace to provide continuous authentication (and
deauthentication) of users. We experimentally assess viability of PoPa in terms
of uniqueness by collecting and evaluating posture patterns of a cohort of
users. Results show that PoPa exhibits very low false positive, and even lower
false negative, rates. In particular, users can be identified with, on average,
91.0% accuracy. Finally, we compare pros and cons of PoPa with those of several
prominent biometric based deauthentication techniques
Eye movements in surgery: A literature review
With recent advances in eye tracking technology, it is now possible to track surgeonsâ eye movements while engaged in a surgical task or when surgical residents practice their surgical skills. Several studies have compared eye movements of surgical experts and novices, developed techniques to assess surgical skill on the basis of eye movements, and examined the role of eye movements in surgical training. We here provide an overview of these studies with a focus on the methodological aspects. We conclude that the different studies of eye movements in surgery suggest that the
recording of eye movements may be beneficial both for skill assessment and training purposes, although more research will be needed in this field
Personalization of Saliency Estimation
Most existing saliency models use low-level features or task descriptions
when generating attention predictions. However, the link between observer
characteristics and gaze patterns is rarely investigated. We present a novel
saliency prediction technique which takes viewers' identities and personal
traits into consideration when modeling human attention. Instead of only
computing image salience for average observers, we consider the interpersonal
variation in the viewing behaviors of observers with different personal traits
and backgrounds. We present an enriched derivative of the GAN network, which is
able to generate personalized saliency predictions when fed with image stimuli
and specific information about the observer. Our model contains a generator
which generates grayscale saliency heat maps based on the image and an observer
label. The generator is paired with an adversarial discriminator which learns
to distinguish generated salience from ground truth salience. The discriminator
also has the observer label as an input, which contributes to the
personalization ability of our approach. We evaluate the performance of our
personalized salience model by comparison with a benchmark model along with
other un-personalized predictions, and illustrate improvements in prediction
accuracy for all tested observer groups
Looks of Love and Loathing:Cultural Models of Vision and Emotion in Ancient Greek Culture
International audienceThis paper considers the intersection of cultural models of emotion, specifically love and envy, with folk and scientific models of vision in Greek antiquity. Though the role of the eyes in the expression of these emotions can intersect with widespread beliefs in vision as a «haptic», material process, analogous to touch and involving physical contact between perceiver and perceived, none the less the emotional concepts resist absorption into a single over-arching theory of the physical effects of seeing and being seen. The specific cultural models of vision («active», «passive», and «interactive») are enlisted in support of cultural models of emotion where they fit, modified where they fit less well, and ignored when they do not fit at all.Cette Ă©tude sâoccupe de lâinteraction des modĂšles culturels de lâĂ©motion. Plus particuliĂšrement elle examine lâamour et la jalousie, notamment en rapport avec les modĂšles populaires et scientifiques de la vision tels quâils Ă©taient perçus dans lâantiquitĂ©. Alors que le rĂŽle jouĂ© par les yeux dans lâexpression des Ă©motions sâentrelace avec les croyances largement rĂ©pandues sur la vision comme processus matĂ©riel tactile Ă©quivalent au touchĂ© et provoquant un contact physique direct entre celui qui perçoit et celui qui est perçu, les concepts Ă©motionnels semblent rĂ©sister Ă une thĂ©orie unique et globalisante couvrant les effets physiques du regard et de la vue. Les modĂšles culturels spĂ©cifiques de la vision (« active », « passive » ou « interactive ») sont ici cataloguĂ©s Ă lâaide des formes culturelles de lâĂ©motion lĂ oĂč ils sont appropriĂ©s ; ils sont modifiĂ©s lĂ oĂč ils sont moins adĂ©quats, voire nĂ©gligĂ©s quand ils nâont pas de pertinence
Proximity and gaze influences facial temperature:a thermal infrared imaging study
Direct gaze and interpersonal proximity are known to lead to changes in psycho-physiology, behaviour and brain function. We know little, however, about subtler facial reactions such as rise and fall in temperature, which may be sensitive to contextual effects and functional in social interactions. Using thermal infrared imaging cameras 18 female adult participants were filmed at two interpersonal distances (intimate and social) and two gaze conditions (averted and direct). The order of variation in distance was counterbalanced: half the participants experienced a female experimenterâs gaze at the social distance first before the intimate distance (a socially ânormalâ order) and half experienced the intimate distance first and then the social distance (an odd social order). At both distances averted gaze always preceded direct gaze. We found strong correlations in thermal changes between six areas of the face (forehead, chin, cheeks, nose, maxilliary and periorbital regions) for all experimental conditions and developed a composite measure of thermal shifts for all analyses. Interpersonal proximity led to a thermal rise, but only in the ânormalâ social order. Direct gaze, compared to averted gaze, led to a thermal increase at both distances with a stronger effect at intimate distance, in both orders of distance variation. Participants reported direct gaze as more intrusive than averted gaze, especially at the intimate distance. These results demonstrate the powerful effects of another personâs gaze on psycho-physiological responses, even at a distance and independent of context
Using social robots to study abnormal social development
Social robots recognize and respond to human
social cues with appropriate behaviors.
Social robots, and the technology used in their
construction, can be unique tools in the study
of abnormal social development. Autism is a
pervasive developmental disorder that is characterized
by social and communicative impairments.
Based on three years of integration
and immersion with a clinical research
group which performs more than 130 diagnostic
evaluations of children for autism per
year, this paper discusses how social robots
will make an impact on the ways in which we
diagnose, treat, and understand autism
The N170 event-related potential differentiates congruent and incongruent gaze responses in gaze leading
To facilitate social interactions, humans need to process the responses that other people make to their actions, including eye movements that could establish joint attention. Here, we investigated the neurophysiological correlates of the processing of observed gaze responses following the participantsâ own eye movement. These observed gaze responses could either establish, or fail to establish, joint attention. We implemented a gaze leading paradigm in which participants made a saccade from an on-screen face to an object, followed by the on-screen face either making a congruent or incongruent gaze shift. An N170 event-related potential was elicited by the peripherally located gaze shift stimulus. Critically, the N170 was greater for joint attention than non-joint gaze both when task-irrelevant (Experiment 1) and task-relevant (Experiment 2). These data suggest for the first time that the neurocognitive system responsible for structural encoding of face stimuli is affected by the establishment of participant-initiated joint attention
Domain general learning: Infants use social and non-social cues when learning object statistics.
Previous research has shown that infants can learn from social cues. But is a social cue more effective at directing learning than a non-social cue? This study investigated whether 9-month-old infants (N = 55) could learn a visual statistical regularity in the presence of a distracting visual sequence when attention was directed by either a social cue (a person) or a non-social cue (a rectangle). The results show that both social and non-social cues can guide infants' attention to a visual shape sequence (and away from a distracting sequence). The social cue more effectively directed attention than the non-social cue during the familiarization phase, but the social cue did not result in significantly stronger learning than the non-social cue. The findings suggest that domain general attention mechanisms allow for the comparable learning seen in both conditions
- âŠ