Raffaella Folgieri
DICo – Digital Information & Communication Departiment
Constancy factors in visual
perception
Gjovik, Norway
Why interest in visual perception?
• to investigate main factors in VR
• to understand boundaries between
perception and cognitive processes
• to find instruments and methods to
analyse human reaction to VR stimuli
• to understand emotional and cognitive
involvement
MOTIVATION
• Investigating emotions in VR
Aims: investigate emotions
in VR
AIMS:
reduce hazards in production
plants and storage sites by addressing
end-users’ practical safety
issues through merging Human
Factors (HF) knowledge and Virtual
Operators virtually immersed in
Reality(VR) technologies
Virthualis project
production plant and in control
room felt emotionally proven
as immersed in real physical
situation
What are potentially influencing factors?
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VR AS A COMMUNICATION PROCESS
• between human beings
• mediated by computer systems
– interaction, visualization and other sensory stimuli
to convey information
• Reality
– is not a intrinsic characteristic of VR
– is the result of a conventional way of coding
information.
A coding whose purpose is to bring the observer to the
conclusion that the VR set is verisimile, i.e. “similar-tothe-real-thing” (or involves similar sensation?)
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VISUAL PERCEPTION RELEVANCE
• Vision is the main sensorial system
• We need to focus on visual perception key factors
– Colors
– Immersivity:
• is the emotional stimulus key factor
• needs all the visual field
– Observer needs to explore actively all the visual fiels
moving head and eyes
• The space and the depth perceptions become
foundamental
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Eat me, Drink me…
What are key
factors in spatial perception?
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SPACE, SIZE AND SHAPE
• Spatial perception depends on multiple aspects
• We focus on three:
• Relative distances
• Size
• Shape
• We experiment some constancy effects, what
are their origin? Perceptual? Cognitive?
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SPATIAL CONSTANCY
Perception viewpoint:
• understand relative
distances and
dimensions
• Interaction:
foundamental role
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SHAPE CONSTANCY (1)
Cognitive viewpoint:
• mental rotation or
translation
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SHAPE CONSTANCY (2)
• In shape constancy effect we have a major role
of high level brain activity: mental rotations!
• We assume that this activity can be detected in
different brain areas, producing strong signals,
to be identified and classified
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EXPERIMENTS AND OBSERVATIONS
• To detect above activity we need to devise
specific experiments
• To observe brain activity we could use:
– fMRI
– Experiments on primate
• Both are invasive/difficult to use in VR
environment
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INVESTIGATION OBJECTIVES
In a VR context:
• fMRI not enough
• Need: uninvasive and portable instrument to
investigate brain activity
– to identify brain areas activated in space and depth
perception processes
– to correlate brain areas to active interactive exploration
of spaces
• This will allows us to
– understand if in VR similarity to phisical reality is
necessary
– find boundaries between perception and cognitive
processes
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EEG in VR: WHAT AND HOW
• Experiments setup
•
VR similar to physical reality
•
Reproducing stimuli through VR far from reality
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MODELS AND METHODS
• Computational models to analyse data from
brain-motion and emotion sensors:
– Brain activity, cardio frequency, sweat, eye,
arms and legs activities
• Data-fusion problem:
– Machine learning methods
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MACHINE LEARNING
Area of Artificial Intelligence concerned with the
development of techniques which allow
computers to "learn".
Machine Learning:
design and development of
algorithms that allow
computers to evolve behaviors
based on empirical data
(sensor data or databases).
We want VR reacting to human perception!
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EXPECTED RESULTS
Indications on brain areas involved in
• VR perception:
• relative distances and dimensions
• interaction
• Cognitive viewpoint:
• objects (mental) recognition
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FINAL OBJECTIVE
Experiments with EEG foundamental for the
realization of algorithms allowing VR to
adapt to human and vice-versa
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Thank you!
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