Brain Dynamic Patterns and the Mind
At what organizational level is consciousness “encoded?”
Posted Mar 06, 2017
Efforts to find the bases for our conscious experiences are normally divided into two general categories: the easy problem and the hard problem. The easy problem is concerned with various electrical or chemical measures of brain function that occur in different mental states. These measures, called conscious correlates or signatures of consciousness are revealed with various brain imaging methods as well as by the mental conditions of patients with brain injury or disease. By contrast, the hard problem is concerned with the very existence of the amazing phenomenon of consciousness itself. Many scientists do not consider the hard problem to be a scientific problem at all; they would leave this issue to the philosophers.
Nearly all agree that the easy problem is nicely dealt with by mainstream science, but attitudes toward the hard problem seem to cover the following range: (1) There is no hard problem. “Mind” is simply another name for brain processes that obey physical laws; end of story (This position is labeled Type A Materialism, one of six categories described by philosopher David Chalmers). (2) Yes, there is a problem, but we should not admit it; such talk only encourages extra-scientific “mystical thinking.” (3) Yes, there is a problem, but it’s far too hard for today’s science to deal with. (4) Yes, the hard problem is very hard, but perhaps we can take some tiny steps towards better understanding by first addressing the easy problem with our scientific tools. We can then follow the implications of this “easy” information to address the hard problem.
Later posts will examine these philosophical positions in more depth, but this post focuses on the activity patterns of minds, the so-called signatures of consciousness partly revealed by brain imaging and other scientific methods. This approach is fully consistent with all four attitudes listed above. I adopt the label “brain pattern” in the broad sense, indicating the dynamic (ever changing) properties of electrical, chemical, or other events in brain tissue, analogous to weather patterns over the earth. Such brain patterns reveal important aspects of our mental states. Physicists often call such dynamic patterns “fields.” Thus, scientists speak of temperature fields, electromagnetic fields, gravitational fields, various kinds of information fields, human population fields, brain activity fields, and many more.
The concept of a brain pattern’s spatial scale of description is nicely illustrated by a metaphor employing the temperature maps that routinely appear in our news media. Scientific data like temperature are recorded with very limited spatial and temporal resolutions. For example, TV weather channels show color maps of temperature distribution (world, national, state, or smaller scale) at some “fixed time” (actually a time average). The smallest regions over which temperatures are averaged and the shortest corresponding time averages determine the spatial and temporal resolutions of the patterns or maps. Thus, each pattern or map location is not really a “point,” but actually represents the estimated average temperature over some local region, perhaps a 10x10 square mile area near ground level. But, many smaller hot and cold areas occur inside such large regions, forming dynamic sub-patterns that the large-scale temperature map cannot reveal. On a hot day, intermediate-scale cold regions occur inside air conditioned homes, even smaller-scale hot regions occur near active ovens, and so forth. Even human bodies raise local small-scale temperature patterns somewhat.
The accompanying fractal image demonstrates the importance of spatial scale when describing patterns, maps, or fields. Fractals are patterns in which magnification of any small part of an image reveals new, smaller scale patterns that generally differ from the larger pattern, but share some statistical properties (called “self-similarity”). Consciousness occurs only when brain patterns exhibit special kinds of changes over time. For example, if this figure were to correspond to some physical state of the brain, parts of this pattern must apparently persist for at least one-half second for consciousness to occur (an outcome based on studies involving brain stimulation or sensory input). Thus, our subjective experience of the “now” is really the “remembered present,” a time averaged state over the past half second or so. Other important time-dependent behaviors seemingly required for consciousness to occur include the various brain rhythms revealed with EEG (“brain wave”) recordings.
A natural question is whether there exists some special scale of brain pattern; let’s call it the C-scale (consciousness scale) which either “equals” mind (attitude one) or “encodes” mind (attitude four). Many scientists emphasize the single neuron scale, in which case each brain neuron is analogous to a single pixel in a pattern, map, or photograph. However, brain science has revealed conscious signatures at many levels: the single neuron, averages over millions of neurons (EEG), and several intermediate scales. Given these data, we can question whether such special C-scale actually exists. That is, perhaps consciousness is fundamentally a multi-scale phenomenon, meaning that consciousness “equals” or is “encoded” by patterns that develop over a broad range of scales. By analogy, the human social system is fundamentally a multi-scale phenomenon, involving interactions at the individual, neighborhood, city, state, and nation scales. In this view, consciousness is “encoded” in (or “equals”) dynamic patterns occurring at multiple scales. Furthermore, perhaps consciousness is intimately associated with cross scale interactions, both bottom-up and top-down as discussed in earlier posts. Let’s call this idea the multi-scale conjecture. While such conclusion is consistent with both attitudes one and four, it may provide an intriguing basis for deeper studies of the hard problem. To be continued.
David J. Chalmers, The Character of Consciousness (New York: Oxford University Press, 2010)
Gerald M. Edelman and Giulio Tononi, A Universe of Consciousness: How Matter Becomes imagination (New York: Basic Books, 2000)
Paul L. Nunez, Brain, Mind, and the Structure of Reality (New York: Oxford University Press, 2010)
Paul L. Nunez, The New Science of Consciousness: Exploring the Complexity of Brain, Mind, and Self (Amherst, New York: Prometheus Books, 2016)
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