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Biotech Science

Spontaneous Brain Activity and Human Behavior 141

Posted by Zonk
from the argh-me-precious-brains dept.
Dr. Eggman writes "Ars Technica is featuring an article summarizing an interesting and perhaps controversial paper which finds links between spontaneous brain activity and human behavior. Spontaneous, yet organized brain activity has been observed without stimulation and even in humans under anesthesia. This paper attempts to link this activity to the observed variability of human performance in even simple, repeated tasks, hoping to establish a new avenue of research into alternative brain processing theories. 'The subtraction provided a much cleaner connection between the button press and brain activity in the left SMC. Once spontaneous activity was accounted for, noise was down by 60 percent, and the signal to noise ratio in the experiments doubled. Putting this another way, spontaneous activity accounted for about 60 percent of the variation between tests. The authors say that these results show that spontaneous brain activity is more than simply a physiological artifact; it helps account for some of the variability in human behavior. In that sense, they argue for a greater acceptance of the view that our brain may have some intrinsic activity that's somewhat independent of sensory input.'"
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Spontaneous Brain Activity and Human Behavior

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  • Free will. (Score:1, Interesting)

    by Anonymous Coward on Friday October 05, 2007 @07:36PM (#20874969)
    About time some hard evidence confirmed what us duelists have known all along. Finally the old dogma of reductionism can be laid to rest.
  • by Anonymous Coward on Friday October 05, 2007 @08:13PM (#20875317)
    Everything I know about my brain is mediated knowledge. Other people (lots of other people whom I never met) with specialized equipment (which I will never get to use) have been studying the brain for generations. They have formed many elaborate models about how it works, what it does, and how it accounts for human behavior. Then, they shared these models with the world (including me).

    My experience of my mind, however is immediate. I sense it directly. I didn't become aware of it by being told it was there, I became aware of it by feeling it.

    So, in a very concrete sense, my mind is more real to me than my brain. I have experienced my mind directly, whereas I have only heard about my brain second-hand. What sense does it make for me to believe that something which I experience moment-by-moment isn't real because of its incompatibilities between some idea of how things work which I have only experienced, and can only ever experience, second-hand?

    Scientists model our experience of reality. These models are not perfect; they have gaps. We shouldn't respond to these gaps by pretending that reality has them too. We should simply recognize them as gaps and continue to study what we can.

  • Re:Mind (Score:4, Interesting)

    by Artifakt (700173) on Saturday October 06, 2007 @12:21AM (#20876679)
    I'll give you one of the simplest real mysteries:

    Let's go to a movie. We'll sit in a comfy chair, and watch Indiana Jones dodge boulders. What happens?

    1. Usually, a person enters a state that can be described as focused monomania (just as Hypnosis can be described). For an hour and a half, they focus on the film so that they are unaware of anything beyond the edges of the screen. They believe the events shown are every bit as real as real life until the film is over. They jump when Ripley opens a hatch and the ship's cat pops out. They cringe when Michael Myers swings an axe. They get aroused when ... Ahem, I'll keep this within the realm of Slashdot. I don't want to think about what arouses many of you. In fact, it's very hard to enjoy a film at all without getting that deeply into it. People don't just forget their external environment, often they forget their bladders unless the need becomes really critical, or sit so still that a foot 'goes to sleep' or similar effects. It takes a real annoyance to snap many of them out of it, a cell phone ringing, loud talking, or worse (and it's perceived as a distinct annoyance to be 'snapped out of it').

    2. A conscious person, typically of normal mental health, has had an out of the body experience lasting typically 90 minutes or so. The other things in life that can allegedly normally cause such an effect aren't present. There's no chemical disturbance of the brain (as from a hallucinogen). There's no physical disturbance (as from a blow to the head). There's no build up of fatigue toxins (as is sometimes used to explain sleep related mental effects). There's nothing but images, images which in the hands of a skilled artist can be so compelling that we choose to become entangled, enthralled, enraptured.

    3. Now describe it in evolutionary terms: We observe some members of a species that has just developed many of its unique brain functions over the last million years. They have lived for 99.999% of that time in small groups typically numbering less than 30. The single most common predator for that entire time was members of other small groups of humans, who typically were just as virulently cannibalistic as we observe today in chimpanzees. Without any of the causes we normally consider to cause a brain dis-function, these members of that species have become totally oblivious to large numbers of strangers, not of their tribe, they have made a deliberate, determined effort to become so, and to stay in that state for an extended time.

    4. The mystery is, why, after doing that once, do humans not realize what they have done, run out of movie theaters screaming, and never return?
  • by Anonymous Coward on Saturday October 06, 2007 @12:22AM (#20876683)
    The brain's complexity is still too great for us to model in exacting detail. While the conceptual jumps between the functioning of a neuron to the subtleties of human behavior are small, they are nonetheless present (and numerous). It is faith, and nothing more, that inclines you to say that we (the scientists) "know" that the mind is nothing more than the brain's software.

    Don't get me wrong, I love science. It's fruits are in evidence and I study neuroscience as a hobby. However, I do not love arrogance, and I especially do not love the very unscientific practice of drawing conclusions that are outside the scope of the available evidence.

    Our present models of human behavior make some useful predictions, though they are not perfectly accurate and they have a huge gap: the models do not express our common experience of consciousness. The word "conscious" is often used (in a scientific sense) to mean little more than "responsive." However, the connotations that impregnate this word did not come about by accident. The mystery of consciousness, and most importantly its staunchly indeterministic and non-mechanical nature, is a moment-by-moment immediate reality for all humans.

    Some of us have played conceptual games with ourselves in order to rationalize away its existence, because of its theoretically problematic nature. And who am I to say that some of us may not actually be philosophical zombies (i.e., soft machines that perfectly mimic conscious beings)? Be that as it may, my consciousness is far more real to me than anything I could ever read or study via objective experimentation. Any model that excludes it is simply incomplete, and any model that defines it as nothing more than emergent phenomena of deterministic, mechanical processes is simply incorrect.

    I am not a religious man. I do not embrace mythology as reality, even if it comes from a scientist.

  • by Christianson (1036710) on Saturday October 06, 2007 @04:20AM (#20877497)
    Does anybody who has spent more than 2 minutes thinking about the human mind really believe that first argument?

    In the sense that it is an oversimplification, useful to establish things in a word-count limited introduction, but whose primary role seems to be to lead laypeople to grotesque and frightening misapprehensions, no, neuroscientists don't believe that first argument.

    It is unquestionable that there is neural activity in the absence of sensory stimuli or motor response. It is also known that this activity is not unstructured but correlated across the neuronal population (though the significance of this fact is a point of dispute). Nor does anyone assume that this activity does not have the ability to influence the response of an organism -- neuronal activity is neuronal activity.

    At the same time, the paramount task of the nervous system is to process the environment around the organism and respond to it appropriately. To be successful in the natural selection sense, you cannot ignore pain, mating signals, fire, loud noises, sudden movements, etc., and when something comes up, you must be able to formulate and implement a strategy which can actually deal with the situation that stimulus describes. Sensory experience is a huge part of neural activity, and if deprived of it long enough -- so that the only activity is the spontaneous activity mentioned above -- the brain enters a degenerate state. Or, to put it another way, you go insane.

    The nervous system, then, is a massively complex system which has a baseline pattern of activity, is receiving constant input from a variety of sensory organs (even when you close your eyes, or plug your ears, you receive input from them; it's just meaningless), all of which is being modulated by "supervisory systems" (e.g, the dopaminergic and serotonergic systems) that control meta-response properties such as attention, anticipation, learning, expectation, and so on. The debate can be reduced to two issues. The first is: once you have accounted for stimulus-driven activity and the effects of the higher-order supervisory systems, does the baseline activity contribute any significant fraction of the organism's final response? And if so, is the baseline activity no more than the muddled-together echo of past stimulus-driven activity rattling around the recurrent network that is the brain and can thus be regarded as simply random noise, or is it meaningful in its own right?

    The paper in question [neuron.org] tries to address the first of these questions. Their results seem to demonstrate that a large fraction of the inter-trial variability in a motor task cannot be explained by known modulating factors such as attention, and thus can be attributed primarily to the baseline activity. Thus, baseline activity would appear to be a major influence on response. The second question remains open, and it is really the core of the issue. These results, however, go a long way towards making it a pressing issue.

    The experiment may well be scientifically interesting, but not for the reason advertised.

    The experiment is scientifically interesting, and for exactly the reasons advertised. There is a fundamental difference between neuroscience and psychology. One studies the operation of the nervous system, and the other studies the nature of the human mind. The basic element of study of neuroscience is spikes, of which you are never aware; psychology interests itself in thoughts, which (from the perspective of a neuroscientist) we can't even meaningfully define, let alone measure. Perhaps one day we might be able to unite the two, but at this point, a criticism of neuroscience based on psychological principles is no more well-founded than lambasting the mathematics of game theory because it runs afoul of sociological thought.

  • Re:Mind (Score:3, Interesting)

    by jotok (728554) on Saturday October 06, 2007 @09:05AM (#20878741)
    So, we have this idea of the "brain." When we say "brain" we'll just assume that it includes all data ever gathered about the brain by anyone on this planet, ever.

    How did we get that info? Well, we used the senses we have at our disposal...but those are mediated in the brain. And they do not always reflect what we think of as "objective" reality. This is not about subjectivity; this is about our experience being distant from actual events, like how chemical data can be transmitted as either taste or as pain depending on which particular neuron binds to the stimulus molecule.

    So IMO in order to say that the mind is a function of the brain you have to make a lot of assumptions about what the brain are, what the mind are, how they function, etc. I think they are obviously interrelated, but as yet poorly defined and poorly understood concepts.
  • by pla (258480) on Saturday October 06, 2007 @09:26AM (#20878899) Journal
    plus the task to try to think of nothing, which is quite hard

    I don't think you can safely pass that off as a minor little clause in your point - The same problem this FP seems to make.

    Of course we have "spontaneous brain activity" that influences our performance on certain tasks. Most of us call that "thinking", preferably about the problem, but also quite possibly about lunch or that cute tech's short skirt or about why the FSM lets good pasta get overcooked.

    This seems like a non-article. No one seriously believes the human brain does nothing but react to sensory input. It just makes a good model since we have nothing but wild guesses about how our wetware really works.

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