04/12/2011 by admin.

I spent some time many, many years ago in wondering what effective pre-scientific predicting was like. The predictions I was wondering about were not omens from entrails and the like, but good prediction of natural things made without the understanding that we now use. How did ancients forecast the weather for example?

At some point I ran across some person using the biblical phrase “ye can discern the face of the sky; but can ye not discern the signs of the times?” That phrase ‘discern the face of the sky’ is either as old as the original biblical texts or a medieval idiom used in early English translations. In either case it was from before knowledge of clouds, winds, air pressure etc. So the thought came – if you are trying to predict a system that has very complex patterns of elements are not understood – if you personify the system and try to get to feel for the patterns in terms of facial expressions, tones of voice, emotions, intentions, personalities – then you can use all the mental abilities that we have evolved for understanding and predicting people. Then you can learn how to predict weather, keep getting better at it for a life time, share/compare with others, and teach the skill to your children. You get to know the west wind’s personality. You get to see when the sky intends to freeze.

Deric Bownds’ blog (here) has a abstract that reminded me of ‘the face of the sky’. The paper is Bilalic, Langner, Ulrich, Grodd (2011) Many Faces of Expertise: Fusiform Face Area in Chess Experts and Novices, The Journal of Neuroscience:

The fusiform face area (FFA) is involved in face perception to such an extent that some claim it is a brain module for faces exclusively. The other possibility is that FFA is modulated by experience in individuation in any visual domain, not only faces. Here we test this latter FFA expertise hypothesis using the game of chess as a domain of investigation. We exploited the characteristic of chess, which features multiple objects forming meaningful spatial relations. In three experiments, we show that FFA activity is related to stimulus properties and not to chess skill directly. In all chess and non-chess tasks, experts’ FFA was more activated than that of novices’ only when they dealt with naturalistic full-board chess positions. When common spatial relationships formed by chess objects in chess positions were randomly disturbed, FFA was again differentially active only in experts, regardless of the actual task. Our experiments show that FFA contributes to the holistic processing of domain-specific multipart stimuli in chess experts. This suggests that FFA may not only mediate human expertise in face recognition but, supporting the expertise hypothesis, may mediate the automatic holistic processing of any highly familiar multipart visual input.

Unfortunately, I am not able to access the paper. And there was another paper that I also found interesting in the abstract but could not access - Tong, Joyce, Cottrell (2008) Why is the fusiform face area recruited for novel categories of expertise? A neurocomputational investigation:

What is the role of the Fusiform Face Area (FFA)? Is it specific to face processing, or is it a visual expertise area? The expertise hypothesis is appealing due to a number of studies showing that the FFA is activated by pictures of objects within the subject’s domain of expertise (e.g., cars for car experts, birds for birders, etc.), and that activation of the FFA increases as new expertise is acquired in the lab. However, it is incumbent upon the proponents of the expertise hypothesis to explain how it is that an area that is initially specialized for faces becomes recruited for new classes of stimuli. We dub this the “visual expertise mystery.” One suggested answer to this mystery is that the FFA is used simply because it is a fine discrimination area, but this account has historically lacked a mechanism describing exactly how the FFA would be recruited for novel domains of expertise. In this study, we show that a neurocomputational model trained to perform subordinate-level discrimination within a visually homogeneous class develops transformations that magnify differences between similar objects, in marked contrast to networks trained to simply categorize the objects. This magnification generalizes to novel classes, leading to faster learning of new discriminations. We suggest this is why the FFA is recruited for new expertise. The model predicts that individual FFA neurons will have highly variable responses to stimuli within expertise domains.

Their question – ‘exactly how the FFA would be recruited for novel domains of expertise’ – may be that we use a person (or group of persons as in chess) as a sort of default alternative and this allows all of the power of our understanding of others to be used for novel domains. Not a bad trick.

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01/12/2011 by admin.

We really do seem to be in direct contact with the world around us – we can reach out and touch it. But that directness is an illusion; there are many levels of manipulation between reality and our experience of it. Consciousness gives us this sense of presence right ‘here’. We are present in the world at the focal point of a 3 dimensional projection. It seems like we are born with this perspective at least in rudimentary form. It appears to be part of the structure of conscious awareness.

I feel that Metzinger’s descriptions of the nature of consciousness is the best available to date. Before dealing with more complex consciousness, he describes minimal consciousness or ’selfless snapshot consciousness’ which calls the presence of a world:

the most elementary form of conscious experience conceivable: The presence of a world. The phenomenal presence of a world is the activation of a coherent, global model of reality (Constraint 1 - globality) within a virtual window of presence (Constraint 2 - presentationality), a model that cannot be recognized as a model by the system generating it within itself (Constraint 3 - transparency). …If and only if a person is conscious, a world exists for her, and if and only if she is conscious, she can make the fact of actually living in a world available for herself, cognitively and as an agent.

There is an old joke (I will spare your the ethnic language, spoil the joke, but keep the logic): a man has one foot on the dock and one on a boat moving away from the dock, his friends yell “jump, jump”, and he cries “how can I jump when I have no place to stand”. Animals have to know where they are as well as where they are going in the same frame/map/picture/conscious experience. They have to stand ‘here’ or order to jump ‘there’. A world has to exist. But why does it have to have transparency? Metzinger again:

Transparency of internal data-structures is a great advantage for any biosystem having to operate with limited temporal and neural resources. Indeed, it minimizes computational load since it is synonymous to a missing of information on this level of processing: Our representational architecture only allows for a very limited introspective access to the real dynamics of the myriads of individual neural events out of which our phenomenal world finally emerges in a seemingly effortless manner. … Naïve realism hinders the system to lose contact (stops the system from losing contact) with external reality by (due to) getting lost in an introspective exploration of the underlying mechanisms.

Just as we can have a virtual ‘now’ when remembering the past or forecasting the future, we can also have a virtual ‘here’. Memories and imaginings have their own ‘here’s as well as their own ‘now’s. One of the most accessible places to see virtual ‘here’s is in the computer games industry. They work very hard to create a virual conscious ‘here’ using the minimum of code, gadgetry and expense. They can get people (who know throughout the experience that it is all smoke and mirrors) to really feel they are in the virtual world rather than the real one. It is similar to optical illusions where you know that the lines are the same length but you continue to see the illusion in spite of your knowledge.

What does it take to manipulate a person’s conscious ‘here’? Sanchez-vives and Slater reviewed a number of experiments investigating what is effective for virtual presence. (From presence to consciousness through virtual reality; Sanchez-Vives & Slater; Perspectives, Nature Reviews, Neuroscience April 2005)

The graphics frame-rate is positively correlated with reported presence, and the critical minimal frame-rate seems to be ~15 Hz…A lower latency between head movement and display update was also found to be associated… In addition, head tracking, stereopsis and geometric field of view are all associated with higher reported presence. ..Surprisingly, the evidence so far does not support the contention that visual realism is an important contributory factor to presence…In an experiment that exploited the pit room, the scene was displayed at various levels of realism (line drawings, without and with textures, and with photo-realism) in a between-groups design. Although all participants showed a significant increase in heart rate when they encountered the precipice, there were no significant differences in heart rate or reported presence between the different rendering conditions. .. Anecdotal reports indicate that sound has a highly significant impact on presence, and one study showed that spatialized sound was associated with higher reported presence than either no sound or non-spatialized sound…(touch is difficult to mimic but appears to have a definite effect)…One study showed that reported presence was increased when the body was represented by a complete (if crude) virtual body, compared with simple representation by a three-dimensional-arrow cursor. …It was noticed in early studies that many participants — especially those reporting a high degree of presence — were almost unable to move by button pressing, and repeatedly attempted to walk. To reduce the dissociation between proprioception and sensory data, an alternative approach was for subjects to ‘walk in place’ to simulate walking. Experimental results showed that, on average, the participants who moved through the environment using this method reported a significantly higher sense of presence than those who used the mouse-button method. … Other studies have shown a significant positive association between overall body mobilization and reported presence.

It looks as through ‘here’ requires that the timing of events is close, the visual and auditory space is believable and action/reaction/interaction works. It does not depend on believable detail of objects from sight, hearing or touch.

So what does consciousness give us for an advantage when it gives us a ‘here’? The picture still seems very vague to me, with no clear substantial functions for ‘here’ and yet I am sure there is a function. Possibly it provides a place in consciousness to house the ’self’, a window on the world, and a place to stand while interacting with the world, an anchor for the mechanism of space/place/navigation. I have the feeling that there is something I am missing. But for now I will assume that we cannot be acting in the world unless we have a location in the structure of conscious awareness of the world.

There is more to come. Previous posts in this series:

Possible functions of consciousness 1 - leading edge of memory

Possible functions of consciousness 2 – gate to meaning

Possible functions of consciousness 3 – working memory

Possible functions of consciousness 4 – place to imagine

Possible functions of consciousness 5 – create ‘now’

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