http://dl.acm.org/citation.cfm?id=2134203 http://dl.acm.org/citation.cfm?id=2134203 Thu, 01 Mar 2012 00:00:00 GMT 2134203 http://dl.acm.org/citation.cfm?id=2134204
Exposure to distressing computer-generated stimuli and feedback of physiological changes during exposure have been effective in the treatment of anxiety disorders (e.g., social phobia). Here we studied voluntary facial activations as a method for regulating more spontaneous physiological changes during virtual social stimulation. Twenty-four participants with a low or high level of social anxiety activated either the corrugator supercilii (used in frowning) or the zygomaticus major (used in smiling) facial muscle to keep a female or a male computer character walking towards them. The more socially anxious participants had a higher level of skin conductance throughout the trials as compared to less anxious participants.]]> Mon, 05 Mar 2012 00:00:00 GMT 2134204 http://dl.acm.org/citation.cfm?id=2134205
Reading is one of the most well-studied visual activities. Vision research traditionally focuses on understanding the perceptual and cognitive processes involved in reading. In this work we recognize reading activity by jointly analyzing eye and head movements of people in an everyday environment. Eye movements are recorded using an electrooculography (EOG) system; body movements using body-worn inertial measurement units. We compare two approaches for continuous recognition of reading: String matching (STR) that explicitly models the characteristic horizontal saccades during reading, and a support vector machine (SVM) that relies on 90 eye movement features extracted from the eye movement data. We evaluate both methods in a study performed with eight participants reading while sitting at a desk, standing, walking indoors and outdoors, and riding a tram.]]> Mon, 05 Mar 2012 00:00:00 GMT 2134205 http://dl.acm.org/citation.cfm?id=2134206
A reinforcement learning (RL) method was used to train a virtual character to move participants to a specified location. The virtual environment depicted an alleyway displayed through a wide field-of-view head-tracked stereo head-mounted display. Based on proxemics theory, we predicted that when the character approached within a personal or intimate distance to the participants, they would be inclined to move backwards out of the way. We carried out a between-groups experiment with 30 female participants, with 10 assigned arbitrarily to each of the following three groups: In the Intimate condition the character could approach within 0.38m and in the Social condition no nearer than 1.2m.]]> Mon, 05 Mar 2012 00:00:00 GMT 2134206 http://dl.acm.org/citation.cfm?id=2134207
In order to better understand how scene motion is perceived in immersive virtual environments, we measured scene-motion thresholds under different conditions across three experiments. Thresholds were measured during quasi-sinusoidal head yaw, single left-to-right or right-to-left head yaw, different phases of head yaw, slow to fast head yaw, scene motion relative to head yaw, and two scene-illumination levels. We found that across various conditions (1) thresholds are greater when the scene moves with head yaw (corresponding to gain <1.0) than when the scene moves against head yaw (corresponding to gain >1.0), and (2) thresholds increase as head motion increases.]]> Mon, 05 Mar 2012 00:00:00 GMT 2134207 http://dl.acm.org/citation.cfm?id=2134208
The visuospatial learning of a map on cellphone displays was examined. The spatial knowledge of human participants was assessed after they had learned the relative positions of London Underground stations on a map via passive, marginally active, or active exploration. Following learning, the participants were required to answer questions in relation to the spatial representation and distribution of the stations on the map. Performances were compared between conditions involving (1) without auditory cues versus continuous auditory cues; (2) without auditory cues versus noncontinuous auditory cues; and (3) continuous auditory cues versus noncontinuous auditory cues. Results showed that the participants perfomed better following active and marginally-active explorations, as compared to purely passive learning.]]> Mon, 05 Mar 2012 00:00:00 GMT 2134208