Download - Scene perception

9.1 Scene Perception PSYC 579 Topic Presentation, University of British Columbia

Diliara Nasirova

School of Interactive Art and Technology, Simon Fraser University

March 23, 2011

2

Outline

1.  Introduction to Scene Perception

2.  Theories of Scene Perception ■  Coherence Theory ■  Virtual Representation ■  Triadic Architecture

3.  Application to visual design ■  Visual Transitions ■  Attentional Coercion

Diliara Nasirova | PSYC 579 | March 23, 2011

3

Introduction Scene Perception

•  Scene Perception is a visual perception of an environment as viewed by an observer at any given time.


4

Introduction Belief about vision

•  Our brains contain detailed, picture-like representation of the scene


5

Introduction Phenomena against the belief •  Inattentional Blindness:

•  The failure to notice the presence of unattended stimuli, even when they are presented within an observer’s field of view

•  Change Blindness: •  The failure to see changes even

when they are large, anticipated and repeatedly made if they are made during a visual disturbance


Simons and Chabris (1999) “Gorillas in Our Midst: Sustained Inattentional Blindness for Dynamic Events”

6

Introduction Phenomena against the belief •  Inattentional Blindness:

•  The failure to notice the presence of unattended stimuli, even when they are presented within an observer’s field of view

•  Change Blindness: •  The failure to see changes even

when they are large, anticipated and repeatedly made if they are made during a visual disturbance


Rensink RA (2002). Internal vs. external information in visual perception.

7

Introduction Change Blindness demo


http://www.cs.ubc.ca/~rensink/flicker/download/Harborside.mov

8




9




10




11

Introduction If a visual buffer existed…


12

Introduction If there is no buffer…


1.  How is it possible to see change at all? 2.  How might human vision operate?

13

Theories of Scene Perception Coherence theory

•  Coherence theory is based on three related hypotheses 1.  Volatile proto-objects formed rapidly in the visual field (without attention) 2.  Focused attention selects some proto-objects and forms coherence field 3.  Release of focused attention (back to proto-objects)


14


•  Coherence theory is based on three related hypotheses 1.  Volatile proto-objects formed rapidly in the visual field (without attention) 2. Focused attention selects some proto-objects and forms coherence field 3. Release of focused attention (back to proto-objects)


15


•  Coherence theory is based on three related hypotheses 1.  Volatile proto-objects formed rapidly in the visual field (without attention) 2.  Focused attention selects some proto-objects and forms coherence field 3.  Release of focused attention (back to proto-objects)


16

Theories of Scene Perception Coherence theory •  Why observers fail to detect changes in "attended" objects?

■  Small number of items can be attended at any time ■  Not all details can be represented in a coherence field ■  Change blindness results



•  Counterintuitive implications: ■  Only a few items can be

represented ■  The representation details is

limited

•  Why do we not notice these limitations?


Rensink RA (2000a). The dynamic representation of scenes.

18

Theories of Scene Perception Virtual Representation


•  For most tasks, only one object is in play at any time:

19

Theories of Scene Perception Virtual Representation


•  Idea of virtual representation:

■  Create a coherent, detailed representation only of a few objects needed for the task at hand

■  Details about any object should be available on request

•  Provide large savings in computational

resources: memory & processing time

20

Theories of Scene Perception Virtual Representation •  For successful use of virtual representation

eye movements and attentional shifts should be made ■  to the appropriate object ■  at the appropriate time.

•  But what directs these movements and shifts?


Rensink RA (2000). Scene perception.

21

Theories of Scene Perception Triadic Architecture •  A possible solution is a triadic architecture with three systems


Rensink RA (2000). Scene perception.

layout gist

object sketch

22

Theories of Scene Perception Triadic Architecture


Rensink RA (2002). Internal vs. external information in visual perception.

23

Theories of Scene Perception Triadic Architecture •  The representation of a scene

involves the dynamic interaction of three systems.

•  A complete representation of the

scene is never constructed - only one coherent object represented at any one time


24

Application to Visual Design Visual Transitions

•  It is possible for displays to promote or prevent the conditions that create change blindness.

■  Saccade ■  Eye blinks ■  Occlusion ■  Movie cuts ■  Gradual transitions ■  Movement

Diliara Nasirova | PSYC 579 | Jan 26, 2011

25

Application to Visual Design Visual Transitions

Diliara Nasirova | PSYC 579 | Jan 26, 2011

•  Design of displays robust to change blindness: ■  Minimizing saccades (important

information close together) ■  Minimizing number of dynamic

events in the background & foreground

26

Application to Visual Design Visual Transitions •  Change Detection in 3D

Parametric Systems: Human-Centered Interfaces for Change Visualization

1. Change blindness 2. On model (A) and

on periphery (B) visualizations

3. Combined views.


http://www.bentley.com/

27

Application to Visual Design Visual Transitions •  Change Detection in 3D

Parametric Systems: Human-Centered Interfaces for Change Visualization

1. Change blindness 2. On model (A) and

on periphery (B) visualizations

3. Combined views.


29 Diliara Nasirova | PSYC 579 | March 23, 2011

31

Application to Visual Design Attention Coercion •  Taking control of attention and

making the observer see (or not see) any given part of the display.

•  Can be carried out in different ways:

■  High-level interest


32

Application to Visual Design Attention Coercion


•  Taking control of attention and making the observer see (or not see) any given part of the display.

•  Can be carried out in different ways: ■  High-level interest ■  Mid-level directives

33

Application to Visual Design Attention Coercion


•  Taking control of attention and making the observer see (or not see) any given part of the display.

•  Can be carried out in different ways: ■  High-level interest ■  Mid-level directives ■  Low-level salience

34

Conclusion


1.  Change blindness is very general phenomenon.

2.  Only one coherent object can be attended at a time.

3.  The perception of a scene is inherently dynamic.

35

Questions?

•  Thank you…


36

References

1.  Rensink RA (2002). Internal vs. external information in visual perception. Proceedings of the Second International Symposium on Smart Graphics: 63-70. [Smart Graphics 2; Hawthorne, NY, USA.]

2.  Rensink RA (2000). Scene perception. In AE Kazdin (ed.), Encyclopedia of Psychology, vol. 7. (pp. 151-155). New York: Oxford University Press.

3.  Rensink RA (2000a). The dynamic representation of scenes. In DJ Simons (ed.) Change Blindness and Visual Memory (pp. 17-42). London: Psychology Press.

4.  Varakin DA, Levin DT, and Fidler R (2008). Unseen and unaware: implications of recent research on failures of visual awareness for human-computer interface design. Hum.-Comput. Interact., 19:389–422
