...the mechanisms of perception, cognition, and action remain mysterious because they emerge from the real-time interactions of large sets of neurons in densely interconnected, widespread neural circuits. It is time for a large-scale effort in neuroscience to create and apply a new generation of tools to enable the functional mapping and control of neural activity in brains with cellular and millisecond resolution...This initiative, the Brain Activity Map (BAM), could put neuroscientists in a position to understand how the brain produces perception, action, memories, thoughts, and consciousnessThe last phrase, in particular, is borderline delusional. As John Horgan points out, we don't even see the side of the barn yet. Apart from the fact that we don’t know what to include in a simulation and what to leave out, we already have conclusive evidence that a search for a road map of stable neural pathways that can represent brain functions is futile. Edited from Horgan:
...the brain is radically unlike and more complex than any existing computer. A typical brain contains 100 billion cells, and each cell is linked via synapses to as many as 100,000 others. Synapses are awash in neurotransmitters, hormones, modulatory peptide (small proteins), neural-growth factors and other chemicals that affect the transmission of signals, and synapses constantly form and dissolve, weaken and strengthen, in response to new experiences...not only do old brain cells die, new ones can form via neurogenesis...many genes are constantly turning on and off and thereby further altering operations of brain nerve cells...the brain may be processing information at many levels below and above that of individual neurons and synapses...each individual neuron, rather than resembling a transistor, maybe be more like a computer in its own right, engaging in complex information-processing.
I fear that these big, much-hyped initiatives will turn out to be as disappointing as the Decade of the Brain. Rather than boosting the status of neuroscience, they may harm its credibility.A particularly telling story comes from my long time friend and colleague Tony Stretton at the University of Wisconsin, who studies the very simple nervous system of the parasitic nematode Ascaaris suum, that has only 298 neurons, for which a functional circuit from the morphological synapses, scored by electron microscopy, has been obtained. This is just the sort of information the Brain Activity Map project is trying to obtain for our brains. So, do we know how the Ascaris nervous system works? No, we're not even close, because Stretton has discovered that their are numerous peptides (as many as 250) that modulate the activity of neurons. Go figure how neurons in that complex modulatory soup work!! And multiply the problem by at least a billion for our brains.
To be fair, the vigorous discussion over the merits of a big push has led, as Markoff and Gorman describe in the NYTimes, to cast the enterprise as trying to better define the playing field, rather than assuming that we now know what it is.