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Articles 1 - 16 of 16
Full-Text Articles in Social and Behavioral Sciences
Vection During Conflicting Multisensory Information About The Axis, Magnitude And Direction Of Self-Motion, April Ash, Stephen Palmisano
Vection During Conflicting Multisensory Information About The Axis, Magnitude And Direction Of Self-Motion, April Ash, Stephen Palmisano
Faculty of Health and Behavioural Sciences - Papers (Archive)
We examined the vection induced by consistent and conflicting multisensory information about self-motion. Observers viewed displays simulating constant-velocity self-motion in depth while physically oscillating their heads left ^ right or back ^ forth in time with a metronome. Their tracked head movements were either ignored or incorporated directly into the self-motion display (as an added simulated self-acceleration). When this head oscillation was updated into displays, sensory conflict was generated by simulating oscillation along: (i) an orthogonal axis to the head movement; or (ii) the same axis, but in a non-ecological direction. Simulated head oscillation always produced stronger vection than `no …
An Indoor Localisation And Motion Monitoring System To Determine Behavioural Activity In Dementia Afflicted Patients In Aged Care, Matthew D'Souza, Montserrat Ros, Mohanraj Karunanithi
An Indoor Localisation And Motion Monitoring System To Determine Behavioural Activity In Dementia Afflicted Patients In Aged Care, Matthew D'Souza, Montserrat Ros, Mohanraj Karunanithi
Faculty of Health and Behavioural Sciences - Papers (Archive)
Dementia is highly prevalent among the older population. Most patients with dementia are admitted to an aged care facility due to wandering behaviour which tends to result in dangerous scenarios such as straying away from the facility and being seriously injured. Due to the decreasing availability of carers in aged care, there is a need to prioritise monitoring of patients that have a severe case of wondering. The challenge is to allow carers to monitor the status of such patients in terms of position localisation and motion behavioural status, in real-time. The long term behavioural analysis of such patients would …
Directionless Vection: A New Illusory Self-Motion Perception, Takeharu Seno, Y Yamada, Stephen A. Palmisano
Directionless Vection: A New Illusory Self-Motion Perception, Takeharu Seno, Y Yamada, Stephen A. Palmisano
Faculty of Health and Behavioural Sciences - Papers (Archive)
We report a new visual illusion, "directionless vection." When expanding and contracting optic flows are simultaneously presented in the same depth plane, observers can perceive illusory self-motion (vection) without direction
Perception Of Mooney Faces By Young Infants: The Role Of Local Feature Visibility, Contrast Polarity And Motion, Yumiko Otsuka, Harold C. H Hill, So Kanazawa, Masami K. Yamaguchi, Branka Spehar
Perception Of Mooney Faces By Young Infants: The Role Of Local Feature Visibility, Contrast Polarity And Motion, Yumiko Otsuka, Harold C. H Hill, So Kanazawa, Masami K. Yamaguchi, Branka Spehar
Faculty of Health and Behavioural Sciences - Papers (Archive)
We examined the ability of young infants (3- and 4-month-olds) to detect faces in the two-tone images often referred to as Mooney faces. In Experiment 1, this performance was examined in conditions of high and low visibility of local features and with either the presence or absence of the outer head contour. We found that regardless of the presence of the outer head contour, infants preferred upright over inverted two-tone face images only when local features were highly visible (Experiment 1a). We showed that this upright preference disappeared when the contrast polarity of twotone images was reversed (Experiment 1b), reflecting …
Vection Can Be Induced Without Global-Motion Awareness, Takeharu Seno, Stephen A. Palmisano, Hiroyuki Ito, Shoji Sunaga
Vection Can Be Induced Without Global-Motion Awareness, Takeharu Seno, Stephen A. Palmisano, Hiroyuki Ito, Shoji Sunaga
Faculty of Health and Behavioural Sciences - Papers (Archive)
A new vection illusion is reported. Vection was induced even though there was no consciously perceived global display motion corresponding to the self-motion. The resulting experience can be summarised as: ``I feel that I am moving but I do not know why''.
The Spatial Tuning Of "Motion Streak" Mechanisms Revealed By Masking And Adaptation, Deborah Apthorp, John Cass, David Alais
The Spatial Tuning Of "Motion Streak" Mechanisms Revealed By Masking And Adaptation, Deborah Apthorp, John Cass, David Alais
Faculty of Health and Behavioural Sciences - Papers (Archive)
We previously reported that fast-moving dot arrays cause orientation-tuned masking of static gratings (D. Apthorp, J. Cass, & D. Alais, 2010), which we attribute to “motion streaks.” Using similar “streaky” dot motion, we describe spatial frequency tuning of grating threshold elevations caused by masking (Experiment 1) and adaptation (Experiment 2) to motion. To compare the streaks with psychophysical tunings, we Fourier analyzed time-averaged translating dots, which were bandpass (peaking at È2.3 c/deg). Masking, however, was strongest at lower test frequencies (e1 c/deg) and largely isotropic over orientation, although a small orientation-tuned effect occurred at È1.2 c/deg. Results were broadly similar …
Temporal Integration Of Movement: Fhe Time-Course Of Motion Streaks Revealed By Masking, David Alais, Deborah M. Apthorp, Aana Karmann, John Cass
Temporal Integration Of Movement: Fhe Time-Course Of Motion Streaks Revealed By Masking, David Alais, Deborah M. Apthorp, Aana Karmann, John Cass
Faculty of Health and Behavioural Sciences - Papers (Archive)
Temporal integration in the visual system causes fast-moving objects to leave oriented 'motion streaks' in their wake, which could be used to facilitate motion direction perception. Temporal integration is thought to occur over 100 ms in early cortex, although this has never been tested for motion streaks. Here we compare the ability of fast-moving ('streaky') and slow-moving fields of dots to mask briefly flashed gratings either parallel or orthogonal to the motion trajectory. Gratings were presented at various asynchronies relative to motion onset (from to ms) to sample the time-course of the accumulating streaks. Predictions were that masking would be …
Orientation Tuning Of Contrast Masking Caused By Motion Streaks, Deborah Apthorp, John Cass, David Alais
Orientation Tuning Of Contrast Masking Caused By Motion Streaks, Deborah Apthorp, John Cass, David Alais
Faculty of Health and Behavioural Sciences - Papers (Archive)
We investigated whether the oriented trails of blur left by fast-moving dots (i.e., “motion streaks”) effectively mask grating targets. Using a classic overlay masking paradigm, we varied mask contrast and target orientation to reveal underlying tuning. Fast-moving Gaussian blob arrays elevated thresholds for detection of static gratings, both monoptically and dichoptically. Monoptic masking at high mask (i.e., streak) contrasts is tuned for orientation and exhibits a similar bandwidth to masking functions obtained with grating stimuli (È30 degrees). Dichoptic masking fails to show reliable orientation-tuned masking, but dichoptic masks at very low contrast produce a narrowly tuned facilitation (È17 degrees). For …
Motion Streaks In Fast Motion Rivalry Cause Orientation-Selective Suppression, Deborah Apthorp, Peter Wenderoth, David Alais
Motion Streaks In Fast Motion Rivalry Cause Orientation-Selective Suppression, Deborah Apthorp, Peter Wenderoth, David Alais
Faculty of Health and Behavioural Sciences - Papers (Archive)
We studied binocular rivalry between orthogonally translating arrays of random Gaussian blobs and measured the strength of rivalry suppression for static oriented probes. Suppression depth was quantified by expressing monocular probe thresholds during dominance relative to thresholds during suppression. Rivalry between two fast motions or two slow motions was compared in order to test the suggestion that fast-moving objects leave oriented "motion streaks" due to temporal integration (W. S. Geisler, 1999). If fast motions do produce motion streaks, then fast motion rivalry might also entail rivalry between the orthogonal streak orientations. We tested this using a static oriented probe that …
Tilt Aftereffects And Tilt Illusions Induced By Fast Translational Motion: Evidence For Motion Streaks, Deborah Apthorp, David Alais
Tilt Aftereffects And Tilt Illusions Induced By Fast Translational Motion: Evidence For Motion Streaks, Deborah Apthorp, David Alais
Faculty of Health and Behavioural Sciences - Papers (Archive)
Fast-moving visual features are thought to leave neural 'streaks' that can be detected by orientation-selective cells. Here, we tested whether 'motion streaks' can induce classic tilt aftereffects (TAEs) and tilt illusions (TIs). For TAEs, participants adapted to random arrays of small Gaussian blobs drifting at 9.5 deg/s. Following adaptation to directions of 15, 30, 45, 60, 75, and 90 degrees (clockwise from vertical) subjective vertical was measured for a briefly presented test grating. For TIs, the same motions were presented in an annular surround and subjective vertical was measured for a simultaneously presented central grating. All motions were 50% coherent, …
Visual Perception Of Smooth And Perturbed Self-Motion, Robert S Allison, James E. Zacher, Stephen A. Palmisano
Visual Perception Of Smooth And Perturbed Self-Motion, Robert S Allison, James E. Zacher, Stephen A. Palmisano
Faculty of Health and Behavioural Sciences - Papers (Archive)
Successful adaptation to the microgravity environment of space and re-adaptation to gravity on earth requires recalibration of visual and vestibular signals. Despite decades of experimentation, motion sickness, spatial disorientation, reorientation illusions and degraded visuomotor performance continue to impact the availability and effectiveness of astronauts. We have found that incorporating jitter of the vantage point into visual displays produces more compelling illusions of self-motion (vection), despite generating greater sensory conflicts. We will discuss a series of ground-based experiments that examine a range of possible explanations for this phenomenon. Recent neuroimaging and neurophysiological data suggests that accelerating optic flow stimulisuch the jittering …
Accelerating Self-Motion Displays Produce More Compelling Vection In Depth, Stephen A. Palmisano, Robert S Allison, Fiona Pekin
Accelerating Self-Motion Displays Produce More Compelling Vection In Depth, Stephen A. Palmisano, Robert S Allison, Fiona Pekin
Faculty of Health and Behavioural Sciences - Papers (Archive)
We examined the vection in depth induced when simulated random self-accelerations (jitter) and periodic self-accelerations (oscillation) were added to radial expanding optic flow (simulating constant-velocity forward self-motion). Contrary to the predictions of sensory-conflict theory frontal-plane jitter and oscillation were both found to significantly decrease the onsets and increase the speeds of vection in depth. Depth jitter and oscillation had lesser, but still significant, effects on the speed of vection in depth. A control experiment demonstrated that adding global perspective motion which simulated a constant-velocity frontal-plane self-motion had no significant effect on vection in depth induced by the radial component of …
Biological Motion And Face Perception In Autism Spectrum Disorder, K Ruparelia, J O'Brien, J Spencer, Harold C. Hill, A Johnston
Biological Motion And Face Perception In Autism Spectrum Disorder, K Ruparelia, J O'Brien, J Spencer, Harold C. Hill, A Johnston
Faculty of Health and Behavioural Sciences - Papers (Archive)
Abstract presented at The 29th European Conference on Visual Perception, 20-25 August 2006, St Petesburg, Russia
Infants' Discrimination Of Faces By Using Biological Motion Cues, Janine Spencer, Justin O'Brien, Alan Johnston, Harold C. Hill
Infants' Discrimination Of Faces By Using Biological Motion Cues, Janine Spencer, Justin O'Brien, Alan Johnston, Harold C. Hill
Faculty of Health and Behavioural Sciences - Papers (Archive)
We report two experiments in which we used animated averaged faces to examine infants' ability to perceive and discriminate facial motion. The faces were generated by using the motion recorded from the faces of volunteers while they spoke. We tested infants aged 4 ^ 8 months to assess their ability to discriminate facial motion sequences (condition 1) and discrim- inate the faces of individuals (condition 2). Infants were habituated to one sequence with the motion of one actor speaking one phrase. Following habituation, infants were presented with the same sequence together with motion from a different actor (condition 1), or …
Do Infants Use A Generalised Motion Processing System For Discriminating Facial Motion?, J V. Spencer, J M. O'Brien, Harold C. Hill, A Johnston
Do Infants Use A Generalised Motion Processing System For Discriminating Facial Motion?, J V. Spencer, J M. O'Brien, Harold C. Hill, A Johnston
Faculty of Health and Behavioural Sciences - Papers (Archive)
Abstract presented at The 28th European Conference on Visual Perception, 22-26 August 2005, A Coruña, Spain
Coherent Perspective Jitter Induces Visual Illusions Of Self-Motion, Stephen A. Palmisano, Darren Burke, Robert S Allison
Coherent Perspective Jitter Induces Visual Illusions Of Self-Motion, Stephen A. Palmisano, Darren Burke, Robert S Allison
Faculty of Health and Behavioural Sciences - Papers (Archive)
Previous research by Palmisano, Gillam and Blackburn (2000) found that adding coherent perspective jitter to constant velocity radial flow improved visually induced illusions of self-motion (known as vection). This was a surprising finding, because unlike pure radial flow, this jittering radial flow should have generated sustained visual-vestibular conflicts - previously thought to always reduce/impair vection. The current experiments attempted to ascertain the essential stimulus features for this jitter advantage for vection by examining three novel types of jitter display. While adding incoherent jitter to radial flow was found to impair vection, adding coherent non-perspective jitter had little effect on this …