1. A quick introduction to connectionist cognitive architecture Simply a toolbox for creating psychological theories Better than the old “info processing” model - allows easy feedback & parallelism

2. A quick introduction to connectionist cognitive architecture Simply a toolbox for creating psychological theories Better than the old “info processing” model - allows easy feedback & parallelism Assumptions Used The mind: a series of highly interconnected nodes, each encoding a hypothesis

3. A quick introduction to connectionist cognitive architecture Simply a toolbox for creating psychological theories Better than the old “info processing” model - allows easy feedback & parallelism Assumptions Used The mind: a series of highly interconnected nodes, each encoding a hypothesis nodes are organized hierarchically in layers, increasing in abstractness

4. A quick introduction to connectionist cognitive architecture Simply a toolbox for creating psychological theories Better than the old “info processing” model - allows easy feedback & parallelism Assumptions Used The mind: a series of highly interconnected nodes, each encoding a hypothesis nodes are organized hierarchically in layers, increasing in abstractness nodes have a state and trigger point, above which they influence other nodes

5. A quick introduction to connectionist cognitive architecture Simply a toolbox for creating psychological theories Better than the old “info processing” model - allows easy feedback & parallelism Assumptions Used The mind: a series of highly interconnected nodes, each encoding a hypothesis nodes are organized hierarchically in layers, increasing in abstractness nodes have a state and trigger point, above which they influence other nodes nodes tend to excite those in other layers, and inhibit those in the same layer

6. A quick introduction to connectionist cognitive architecture Simply a toolbox for creating psychological theories Better than the old “info processing” model - allows easy feedback & parallelism Assumptions Used The mind: a series of highly interconnected nodes, each encoding a hypothesis nodes are organized hierarchically in layers, increasing in abstractness nodes have a state and trigger point, above which they influence other nodes nodes tend to excite those in other layers, and inhibit those in the same layer on a stimulus, activation spreads through the network until it “settles” into a new state

7. A quick introduction to connectionist cognitive architecture Simply a toolbox for creating psychological theories Better than the old “info processing” model - allows easy feedback & parallelism Assumptions Used The mind: a series of highly interconnected nodes, each encoding a hypothesis nodes are organized hierarchically in layers, increasing in abstractness nodes have a state and trigger point, above which they influence other nodes nodes tend to excite those in other layers, and inhibit those in the same layer on a stimulus, activation spreads through the network until it “settles” into a new state there is a fixed amount of activation available to excite nodes (attention)

8. “It has wings” State = 0.4 An example of a node

9. An example of a network

10. Highly useful psychological modeling tools: Explain attention findings (divided vs. focussed attention) Explain differences between STM and LTM Explain forgetting Explain learning & application of concepts Explain priming effects in cognition generally Explain recognition of recall failure

11. Return to presence - the problem at hand Current approach to understanding presence: identifying variables via empirical manipulation For this to work, need to test as many variables in the same experiment as possible This blind approach gives awesome practical problems!

12. Imagine: want to test the effects of these variables: Stereopsis (yes/no) Avatar animation (yes/no) Field of view (16°/ 32°/ 64°) Display type (MHD/Fishtank/Desktop) Perspective (1st person/3rd person) This requires 2x2x3x3x2 = 72 conditions At a minimum of 12 subjects per condition, 864 subjects!!

13. Apart from this, current research suffers from: Lack of statistical power (small effects, few subjects) Little methodological sophistication (still use 2 group experiments) Conclusions which go beyond data found Lack of understanding of psychological processes of perception

14. Solution to the problem: Follow standard natural science methods: Begin with a model Generate specific hypothesis implied by the model Test these hypotheses to evaluate the validity of the model Advantage of this approach - there is always a defined research goal and avoids many null results

15. Current model of presence Nothing explicitly or formally defined Model seems to be: “Being there” is a consequence of having sensory stimulation approaching that found in natural perception. Problems with this model: No account of higher-level processes (“willing suspension of disbelief”) Gives a technology-centered view of a psychological process It is difficult to understand the implications of such a model Current evidence contradicts it

16. Towards a new model: considerations Things we know about presence, supported by current model: Positive correlations: Realism Attention on the VE Storyline Negative correlations: Bad interface Attention on the RE (BIPs) Poor immersion Most trustworthy results are relational (biggest effects) No information on causality with relational studies

17. From those findings, several things become clear: Direction of attention is important Quality of stimulus is important Interference with the process is possible Top-down processes are important The current presence model does not take many of these points into account: cannot explain why BIPs occur, or why interference should happen does not give any space for top-down processing (such as storyline)

18. Connectionist networks are a possible candidate for modeling: they model attentional processes well they can account for interference they can explain selection between competing stimuli they can account for top-down effects, bottom-up effects as well as their interactions

19. Presence as a form of environmental perception & reaction In my model, presence is a natural process, a part of perception can occur in any setting, not just computer created VEs (theme parks, books, films, etc) Rather than thinking of presence as a “feeling of being there”, look at it from a behaviorist view: During the presence state, subjects are more likely to think and act in a way coherent with the demands of the virtual world rather those of the real world. The dominance of virtually-aligned cognition represents the level of presence. This idea agrees with the classical “being there” idea of presence, but is more operationalized - bridges “presence” and “behavioral presence”

20. My idea of a connectionist model for environmental perception: Perceptual layers Detectors for “real” stimuli Detectors for “image” stimuli Conceptual layers Detectors for other stimuli

21. The center layer (layers) represent them mechanisms which determine presence Detectors for “real” stimuli These nodes become activated when the subject is stimulated by something which is perceived as real (eg. animation, stereo, etc) Detectors for “image” stimuli These nodes are activated when the subject is stimulated by something which is perceived as an image (eg. glint of a photograph, jaggies, etc) As usual, there is vertical excitation and lateral inhibition Detectors for other stimuli These nodes are activated when the subject is stimulated by other stimuli (not emanating from the VE)

22. Perceptual layers Detectors for “real” stimuli Detectors for “image” stimuli Conceptual layers Detectors for other stimuli The high presence situation: Stable state with “Real” cluster most activated

23. Perceptual layers Detectors for “real” stimuli Detectors for “image” stimuli Conceptual layers Example: looking at a photograph (low presence) A Flatness, glossiness, etc. A “I am holding a photo”, etc. Detectors for other stimuli Result: action/thoughts are in terms of an image rather than an object I I

24. A photo is a simple case - the Image perceptions outweigh the Real perceptions In a VE, the Real, Image and Other clusters are competing far more strongly However, in order for a stimulus to affect our actions and thoughts (presence), only one of those middle clusters can remain activated enough to affect the upper layers Consider a “good” VE: high immersion (HMD, earphones), real walking to move

25. Perceptual layers Detectors for “real” stimuli Detectors for “image” stimuli Conceptual layers Example: High immersion VR (high presence): Initial conditions Jaggies, low FOV, etc. “I am in a VE” Detectors for other stimuli

26. Perceptual layers Detectors for “real” stimuli Detectors for “image” stimuli Conceptual layers Example: High immersion VR (high presence): Stable state Detectors for other stimuli Result: action/thoughts are in terms of the VE rather than the RE

27. This is still a more simple case - what about presence with very poor immersion equipment? (Counter Strike presence) In these cases, top-down processing becomes far more important - the storyline finding comes into effect Consider a “bad” VE: low immersion (desktop), but player keen “to be a terrorist” (willing suspension of disbelief)

28. Perceptual layers Detectors for “real” stimuli Detectors for “image” stimuli Conceptual layers Example: Low immersion VR (high presence): Initial conditions Jaggies, flatness, etc. “I am in playing a game” Detectors for other stimuli “I am a terrorist” disctractions

29. Perceptual layers Detectors for “real” stimuli Detectors for “image” stimuli Conceptual layers Example: Low immersion VR (high presence): Stable state Detectors for other stimuli Result: action/thoughts are in terms of the VE rather than the RE (moderate amount)

30. Evaluation of the new model - explaining acquisition of the presence state Strengths: Can explain high presence levels in low immersion situations Can explain low presence in high immersion situations Agrees with the “holodeck” idea (lucid dreaming) Supersedes and expands the previous model Weaknesses: Vague about the processes in the conceptual layers (key to presence) Division of middle layer into three clusters seems abitrary The “other” cluster is a bit of a kludge to explain distractions

31. Further explanations allowed by this model - failures of presence Failure due to interference - distractions High levels of activation of the “other” cluster will inhibit activation in the “Real” cluster These distraction can come from below (extraneous sounds etc.) or from above (dual tasks eg. BIP detections) Distractions can block presence, or merely reduce it This explains the lower “presence power” of low immersion systems

32. Failure due to poor stimulus quality The VE stimuli are always occurs in the presence of other stimuli For the “Real” node to become dominant, the “Real” stimuli must be high enough to overcome “Image” and “Other” if the stimuli is too poor, “Image” will inhibit “Real” too much Poor stimuli do not ensure zero presence, but certainly lower levels

33. Failure due to non-compliant subject This is a more complex situation - involves 2 simultaneous failures The first is interference - a non-compliant subject will be attending to personal thoughts, activating the “Other” cluster from above The second is a lack of top-down activation of the “Real” node. This will make it harder to make it dominant

34. Predictions from the connectionist model Many predictions can be directly made from this model, such as: A low immersion, poor quality system can still create high levels of presence - prime the subject, reduce distractions Task performance in VR will be increased in high presence situations only if the task requires thought in terms of the VE (spacial or thematic) Conversely, these translate into recommendations which we can make to VR authors: Give more importance to the subject’s mental set (priming materials) Ensure that immersion is increased, even if stimulus quality is low Tap into user’s previous experiences where possible (increase top-down activation)

35. Empirically testing the model Key statement of the theory: Presence levels are determined by stimulus quality, priming, distractions all singly as well as in interaction This should be directly tested, as it is the foundation of the theory One possibility - use a 3-way factorial design (allows checking main effects and interactions)

36. Set up a 3x2x3 design (about 50 subjects if we use repeated measures - not ideal) Variable 1: stimulus quality - 3 levels Stereo, textured, radiosity Mono,textured Mono, flat shading Variable 2: priming - 3 levels preparatory video/booklet/briefing no preparation Variable 3: distraction - 3 levels no distraction, visual or auditory infrequent, slight distractions frequent intense distractions

37. Should find: Each variable makes a difference to presence levels individually Interactions between variables (eg. high presence when priming was high but only if distractions were low as well)