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The tale of the neuroscientists and the computer: why mechanistic theory matters.

Brown JW - Front Neurosci (2014)

View Article: PubMed Central - PubMed

Affiliation: Psychological and Brain Sciences, Indiana University Bloomington, IN, USA.

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A little over a decade ago, a biologist asked the question “Can a biologist fix a radio?” (Lazebnik, )... That question framed an amusing yet profound discussion of which methods are most appropriate to understand the inner workings of a system, such as a radio... For the engineer, the answer is straightforward: you trace out the transistors, resistors, capacitors etc., and then draw an electrical circuit diagram... This resting network is slightly different across different computers in a way that correlates with their processor speed, memory capacity, etc., and thus it is possible to predict various capacities and properties of a given computer by measuring its activity pattern when idle... Another flurry of publications results... This allows them to use MRI to diagnose other computers with broken disk controllers... They conclude that the disk controller plays a key role in mediating disk access, and this is confirmed with a statistical mediation analysis... Someone even develops the technique of Directional Trunk Imaging (DTI) to characterize the structure of the ribbon cables (fiber tract) from the disk controller to the hard disk, and the results match the functional correlations between the hard disk and disk controller... Similar investigations of nearby regions of the CPU yield similar results, while antidromic stimulation reveals inputs from related number-representing regions... In the end, the neurophysiologist concludes that the cells in this particular CPU region have receptive fields that respond to different kinds of numbers, so this must be a number representation area... But for all of this, have the neuroscientists really understood how the computer works? The moral of the story is twofold: first, that we sorely need a foundational mechanistic, computational framework to understand how the elements of the brain work together to form functional units and ultimately generate the complex cognitive behaviors we study... If we really care about the question of how the brain works, we must not delude ourselves into thinking that simply collecting more empirical results will automatically tell us how the brain works any more than measuring the heat coming from computer parts will tell us how the computer works... Instead, our experiments should address the questions of what mechanisms might account for an effect, and how to test and falsify specific mechanistic hypotheses (Platt, ).

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The inside of a typical computer, showing CPU, hard disk, memory, and disk controller.
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Figure 1: The inside of a typical computer, showing CPU, hard disk, memory, and disk controller.

Mentions: Within the fields of systems, cognitive, and behavioral neuroscience in particular, I fear we are in danger of losing the meaning of the Question “how does it work?” As the saying goes, if you have a hammer, everything starts to look like a nail. Having been trained in engineering as well as neuroscience and psychology, I find all of the methods of these disciplines useful. Still, many researchers are especially well-trained in psychology, and so the research questions focus predominantly on understanding which brain regions carry out which psychological or cognitive functions, following the established paradigms of psychological research. This has resulted in the question being often reframed as “what brain regions are active during what psychological processes,” or the more sophisticated “what networks are active,” instead of “what mechanisms are necessary to reproduce the essential cognitive functions and activity patterns in the system.” To illustrate the significance of this difference, consider a computer (Figure 1). How does it work?


The tale of the neuroscientists and the computer: why mechanistic theory matters.

Brown JW - Front Neurosci (2014)

The inside of a typical computer, showing CPU, hard disk, memory, and disk controller.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4215610&req=5

Figure 1: The inside of a typical computer, showing CPU, hard disk, memory, and disk controller.
Mentions: Within the fields of systems, cognitive, and behavioral neuroscience in particular, I fear we are in danger of losing the meaning of the Question “how does it work?” As the saying goes, if you have a hammer, everything starts to look like a nail. Having been trained in engineering as well as neuroscience and psychology, I find all of the methods of these disciplines useful. Still, many researchers are especially well-trained in psychology, and so the research questions focus predominantly on understanding which brain regions carry out which psychological or cognitive functions, following the established paradigms of psychological research. This has resulted in the question being often reframed as “what brain regions are active during what psychological processes,” or the more sophisticated “what networks are active,” instead of “what mechanisms are necessary to reproduce the essential cognitive functions and activity patterns in the system.” To illustrate the significance of this difference, consider a computer (Figure 1). How does it work?

View Article: PubMed Central - PubMed

Affiliation: Psychological and Brain Sciences, Indiana University Bloomington, IN, USA.

AUTOMATICALLY GENERATED EXCERPT
Please rate it.

A little over a decade ago, a biologist asked the question “Can a biologist fix a radio?” (Lazebnik, )... That question framed an amusing yet profound discussion of which methods are most appropriate to understand the inner workings of a system, such as a radio... For the engineer, the answer is straightforward: you trace out the transistors, resistors, capacitors etc., and then draw an electrical circuit diagram... This resting network is slightly different across different computers in a way that correlates with their processor speed, memory capacity, etc., and thus it is possible to predict various capacities and properties of a given computer by measuring its activity pattern when idle... Another flurry of publications results... This allows them to use MRI to diagnose other computers with broken disk controllers... They conclude that the disk controller plays a key role in mediating disk access, and this is confirmed with a statistical mediation analysis... Someone even develops the technique of Directional Trunk Imaging (DTI) to characterize the structure of the ribbon cables (fiber tract) from the disk controller to the hard disk, and the results match the functional correlations between the hard disk and disk controller... Similar investigations of nearby regions of the CPU yield similar results, while antidromic stimulation reveals inputs from related number-representing regions... In the end, the neurophysiologist concludes that the cells in this particular CPU region have receptive fields that respond to different kinds of numbers, so this must be a number representation area... But for all of this, have the neuroscientists really understood how the computer works? The moral of the story is twofold: first, that we sorely need a foundational mechanistic, computational framework to understand how the elements of the brain work together to form functional units and ultimately generate the complex cognitive behaviors we study... If we really care about the question of how the brain works, we must not delude ourselves into thinking that simply collecting more empirical results will automatically tell us how the brain works any more than measuring the heat coming from computer parts will tell us how the computer works... Instead, our experiments should address the questions of what mechanisms might account for an effect, and how to test and falsify specific mechanistic hypotheses (Platt, ).

No MeSH data available.