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Cited by 1,358Philosophy and History of ScienceUndergraduate Neuroscience Education and ResearchPhilosophy and Theoretical Science

Neuroscience Needs Behavior: Correcting a Reductionist Bias

Open access
Krakauer, John W., Ghazanfar, Asif A., Gomez-Marin, Alex, MacIver, Malcolm A., Poeppel, David·2017·Neuron
DOI 10.1016/j.neuron.2016.12.041
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Abstract

There are ever more compelling tools available for neuroscience research, ranging from selective genetic targeting to optogenetic circuit control to mapping whole connectomes. These approaches are coupled with a deep-seated, often tacit, belief in the reductionist program for understanding the link between the brain and behavior. The aim of this program is causal explanation through neural manipulations that allow testing of necessity and sufficiency claims. We argue, however, that another equally important approach seeks an alternative form of understanding through careful theoretical and experimental decomposition of behavior. Specifically, the detailed analysis of tasks and of the behavior they elicit is best suited for discovering component processes and their underlying algorithms. In most cases, we argue that study of the neural implementation of behavior is best investigated after such behavioral work. Thus, we advocate a more pluralistic notion of neuroscience when it comes to the brain-behavior relationship: behavioral work provides understanding, whereas neural interventions test causality.

AI snapshot

Written from the paper’s full text.

TL;DR

This perspective argues that neuroscience’s dominant reductionist/interventionist program—using neural manipulation to test necessity and sufficiency—is not sufficient to understand how the brain generates behavior. It advocates a more pluralistic neuroscience in which detailed behavioral and task decomposition provides understanding, while neural interventions test causality.

Key findings

  • Causal manipulation at the neural level is not equivalent to understanding: necessity/sufficiency claims can identify starting conditions or correlates but do not explain the algorithms or component processes that generate behavior.
  • Multiple realizability and degeneracy mean the same behavior can arise from different circuit configurations, and the same circuit can generate different behaviors, so neural data alone cannot reliably infer behavioral-level processes.
  • The Jonas and Kording microprocessor study is used as an empirical demonstration: applying neuroscience techniques to a known microprocessor and three videogames failed to reverse-engineer its stored-program architecture; the analyzed “behavior” was 10 s of spontaneous activity with no player playing the game.
  • The paper gives four examples where behaviorally driven work yielded more complete insights—bradykinesia, sound localization, electrolocation/jamming avoidance response, and motor learning—and argues that behavioral work is often epistemologically prior to neural implementation studies.

Methods

  • Perspective/conceptual article, not a primary empirical study; no formal experimental design, sample, or statistical analysis is reported.
  • The argument is developed through selected examples from prior literature, including the microprocessor analogy, C. elegans, mirror neurons, bird flocking, Parkinson’s disease/bradykinesia, barn owl and gerbil sound localization, weakly electric fish electrolocation, and sensorimotor adaptation.
  • Main analysis is conceptual and philosophical: it contrasts interventionist causal explanation with Marr’s computational/algorithmic/implementation levels and argues for behavioral task decomposition before neural implementation work.

Limitations

  • The paper states no formal limitations section.
  • Evident from the text: as a perspective piece, it does not systematically review the literature or empirically test its claims; its examples are selected to support the argument.
  • Evident from the text: it offers no quantitative synthesis or predefined criteria for when behavioral work should precede neural work, so the recommendation remains a conceptual and methodological stance.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1016/j.neuron.2016.12.041

Cites

71 of 71 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 59 cited sources checked · 0 supported · 0 flagged

  • Premisecitation

    The same behavior may result from alternative circuit configurations.

    “The same behavior may result from alternative circuit configurations”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Marder and Goaillard, 2006

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  • Premisecitation

    The same behavior may result from different circuits altogether.

    “from different circuits altogether”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Katz, 2016 source

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  • Premisecitation

    The same circuit may generate different behaviors.

    “the same circuit may generate different behaviors”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Katz, 2016 source

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  • Premisecitation

    The brain's deep degeneracy makes the causal manipulation approach not sufficient for gaining a full understanding of the brain's role in behavior.

    “When this concern is coupled with the brain's deep degeneracy, it becomes apparent that the causal manipulation approach is not sufficient for gaining a full understanding of the brain's role in behavior”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Marom et al., 2009 source

      Not checked in the free run.

  • Interpretationnone given

    Detailed analysis of tasks and of the behavior they elicit is best suited for discovering component processes and their underlying algorithms.

    “Specifically, the detailed analysis of tasks and of the behavior they elicit is best suited for discovering component processes and their underlying algorithms.”
    Quote in the paperNot a substantial claim
  • May combine two claims. 16
  • Classified as probably not a substantial claim. 27

  • May combine two claims.

    Interpretationreasoning

    Behavioral work provides understanding, whereas neural interventions test causality.

    “behavioral work provides understanding, whereas neural interventions test causality.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    In most cases, study of the neural implementation of behavior is best investigated after behavioral work.

    “In most cases, we argue that study of the neural implementation of behavior is best investigated after such behavioral work.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Interpretationcitation

    Technique-driven neuroscience could be considered an example of substitution bias.

    “Technique-driven neuroscience could be considered an example of what is known as the substitution bias”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Kahneman, 2011

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  • May combine two claims.

    Interpretationcitation

    Pure behavioral experiments are of critical importance and highly informative in their own right, but have increasingly been marginalized or at best postponed.

    “Despite this pure behavioral step being of critical importance and highly informative in its own right, it has increasingly been marginalized”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Anderson and Perona, 2014

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    Interpretationcitation

    Correctly labeling something as behavior is contingent on the outcome of an investigation into what the animal does to ensure its survival in its native habitat.

    “correctly labeling something as behavior is contingent on the outcome of an investigation into what the animal does to ensure its survival in its native habitat.”
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    • cites Tinbergen, 1963 source

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  • Probably not a substantial claim: may not pass S2 (checkable), S4 (based).

    Interpretationnone given

    It is disturbingly common for studies to include behavior as simply a hasty add-on in papers otherwise crammed full of multiple techniques, types of results, and even species.

    “It is disturbingly common for studies to include behavior as simply a hasty add-on in papers that are otherwise crammed full of multiple techniques, types of results, and even species.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    The question of how the brain generates behavior is best answered through precise hypotheses articulated in an a priori conceptual framework, careful task design, and collection of behavioral data.

    “This is a question best answered through precise hypotheses articulated in an a priori conceptual framework, careful task design, and the collection of behavioral data.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S4 (based).

    Interpretationnone given

    The first step for developing conceptual frameworks that meaningfully relate neural circuits to behavioral predictions is to design hypothesis-based behavioral experiments.

    “The first step for developing conceptual frameworks that meaningfully relate neural circuits to behavioral predictions is to design hypothesis-based behavioral experiments.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationcitation

    Understanding something is not the same as just describing it or knowing how to intervene to change it.

    “understanding something is not the same as just describing it or knowing how to intervene to change it.”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Marr, 1982

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    • cites Anderson, 1972 source

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    • cites Bechtel, 2008

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    Interpretationreasoning

    It is a significant confusion to label a coordinated response to a stimulus a behavior without first determining the relevance of the response to the animal's natural life.

    “It is therefore a significant confusion to label a coordinated response to a stimulus a ''behavior'' without first determining the relevance of the response to the animal's natural life”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Premisecitation

    The tendency to ascribe psychological properties to single neuron activity that can only be sensibly ascribed to a whole behaving organism is known as the mereological fallacy.

    “This tendency to ascribe psychological properties to single neuron activity that can only be sensibly ascribed to a whole behaving organism is known as the mereological fallacy”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Smit and Hacker, 2014

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  • May combine two claims.

    Premisereasoning

    Flocking in birds is an emergent behavior that can only be understood at the algorithmic level, which in turn can only be determined by studying the emergent behavior itself.

    “An example of an emergent behavior that can only be understood at the algorithmic level, which in turn can only be determined by studying the emergent behavior itself, is flocking in birds.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Reynolds, 1987 source

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    Premisecitation

    A central pattern generator may be understood better using the intentional stance.

    “a central pattern generator may be understood better using the intentional stance”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites Dennett, 1989

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    • cites comment by Grillner in Selverston, 1980

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  • May combine two claims.

    Interpretationreasoning

    Behavior itself is emergent from aggregated neural circuits and therefore should also be studied in its own right.

    “behavior itself is emergent from aggregated neural circuits and therefore should also be studied in its own right.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationnone given

    The treatment of behavior in the Jonas and Kording study perfectly represents how the neuroscience field typically tends to work with this concept.

    “The treatment of ''behavior'' perfectly represents how the neuroscience field typically tends to work with this concept.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Interpretationreasoning

    Additional behavioral evidence that the participant understands the other individual is lacking.

    “Additional behavioral evidence that the participant understands the other individual is lacking.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    Many commentaries pointed out that increasingly complete descriptions at one level do not serve as a bridge to the next level.

    “Many of the commentaries pointed out, however, that increasingly complete descriptions at one level do not serve as a bridge to the next level.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Selverston, 1980 source

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  • Classified as probably not a substantial claim.

    Interpretationreasoning

    No overt new theory is offered that will bridge ensemble activity and behavior.

    “No overt new theory, however, is offered that will bridge ensemble activity and behavior.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    Empirical and theoretical behavioral work would complement causal explanations at the neural and circuit level.

    “This work would complement causal explanations at the neural and circuit level.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    Every scientist takes a philosophical position, either tacitly or explicitly, whenever they state that a result is important, fundamental, or interesting.

    “Every scientist takes a philosophical position, either tacitly or explicitly, whenever they state that a result is ''important,'' ''fundamental,'' or ''interesting.''”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S4 (based). May combine two claims.

    Interpretationreasoning

    There is no interesting variable inherent to the data that can be objectively plotted on a graph; abstract reasoning and normative claims cannot be substituted by, or obtained from, data.

    “There is no ''interesting'' variable inherent to the data that can be objectively plotted on a graph-abstract reasoning and normative claims cannot be substituted by, or obtained from, data.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    Ion channels do not cause the cardiac rhythm; the rhythm just is the combination of the higher level of the cell membrane and the lower level of ion channels.

    “The conceptual point is that the ion channels do not cause the cardiac rhythm-instead the rhythm just is the combination of the higher level of the cell membrane and the lower level of ion channels.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S4 (based).

    Interpretationreasoning

    Assertions that a result is important, fundamental, or interesting are always a judgment from outside of science.

    “This is because such assertions are always a judgment from outside of science.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable). May combine two claims.

    Interpretationreasoning

    If the question is how the brain leads to behavior, we are first asking why the brain is performing this behavior and then asking how it is doing it.

    “if the question is ''how does the brain lead to behavior?''we are first asking why is the brain performing this behavior and then asking how is it doing it.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    Understanding that the flapping of wings is critical to flight aids the subsequent study of feathers.

    “understanding that the flapping of wings is critical to flight aids the subsequent study of feathers.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    Ion channels do not beat; heart cells do.

    “Ion channels do not beat, heart cells do.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    The best way to answer which patterns in the data should be selected for further investigation is to examine the game-play, the behavior, itself.

    “The best way to answer this would be to examine the game-play-the behavior-itself.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable). May combine two claims.

    Interpretationreasoning

    It is unlikely that, from the outset, studying an ostrich feather in isolation would lead to the conclusion that there is such a phenomenon as flight or even that feather-like structures would be useful for flight.

    “It is unlikely that, from the outset, studying an ostrich feather in isolation would lead to the conclusion that there is such a phenomenon as flight or even that feather-like structures would be useful for flight.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Analysis of the JAR behavior was first performed by investigators who built a simple virtual world for electric fish, resulting in reliable elicitation of the JAR.

    “Analysis of the behavior was first performed by investigators who built a simple virtual world (Box 1) for electric fish: a small tank in which a fish's own electric field was picked up, then slightly shifted in frequency and fed back, resulting in the reliable elicitation of what is now called the JAR (Watanabe and Takeda, 1963).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Watanabe and Takeda, 1963

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  • Probably not a substantial claim: may not pass S2 (checkable). May combine two claims.

    Interpretationreasoning

    The use of filler terms signals a tacit awareness of the lack of, and a desire for, a different kind of understanding, which can be obtained by doing empirical and theoretical behavioral work.

    “Importantly, however, the use of filler terms signals a tacit awareness of the lack of, and a desire for, a different kind of understanding, which we argue can be obtained by doing empirical and theoretical behavioral work.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    Neural circuits do not feel pain; whole organisms do.

    “Neural circuits do not feel pain, whole organisms do.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable). May combine two claims.

    Interpretationreasoning

    This activity is a fragment of activity, which is stimulus-response rather than behavior, an adaptive pattern of activity that enhances fitness.

    “This is a fragment of activity, which we refer to as ''stimulus-response'' (Box 1) to distinguish it from behavior, an adaptive pattern of activity (i.e., one that enhances fitness).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    It is now known from careful psychophysical work that many distinct learning algorithms operate together to counter the effects of a perturbation during adaptation, even though phenotypically their summed behavior can look like pure error-based cerebellar learning.

    “Crucially, however, it is now known from careful psychophysical work that many distinct learning algorithms operate together to counter the effects of a perturbation during adaptation, even though phenotypically their summed behavior can look like pure error-based cerebellar learning (Huang et al., 2011;Taylor et al., 2014).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites Huang et al., 2011 source

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    • cites Taylor et al., 2014 source

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    Premisecitation

    Because the electric field is controlled by the fish's motor system, it enabled the complete characterization of a behavior using precisely controlled signals and set the groundwork for Heiligenberg's subsequent discoveries of the circuits underlying the behavior.

    “As the electric field is controlled by the fish's motor system, it enabled the complete characterization of a behavior using precisely controlled signals and set the groundwork for Heiligenberg's subsequent discoveries of the circuits underlying the behavior (Heiligenberg, 1991).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Heiligenberg, 1991

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  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Science is driven by both technological advances and a guiding vision.

    “As Woese has argued (Woese, 2004), science is driven by both technological advances and a guiding vision.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Woese, 2004 source

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  • Probably not a substantial claim: may not pass S2 (checkable). May combine two claims.

    Interpretationreasoning

    Since the causal-manipulation view by itself will not lead to understanding, a more pluralistic conception of mechanistic understanding can only help neuroscience.

    “Since the causal-manipulation view by itself will not lead to understanding, a more pluralistic conception of mechanistic understanding can only help neuroscience.”
    Quote in the paperNot a substantial claim
36 of 36

  • The paper relies on this without support.

    The brain-behavior relationship is usefully analogous to the software-hardware distinction in computer science.

    “An analogy from computer science that has both historical and conceptual appeal is the distinction between software and hardware; whereby the software represents ''what'' the brain (or one of its modules) is doing, and the hardware represents ''how'' it is doing it.”

  • The paper relies on this without support.

    A microprocessor is sufficiently analogous to a brain that failure of neuroscience techniques to reverse engineer it demonstrates limits of those techniques for understanding the brain.

    “In a nice irony, the computer science analogy has come full circle with a provocative study that applied numerous neuroscience techniques to a single microprocessor (analogous to a brain) in an attempt to understand how it controls three classic videogames (analogous to behaviors)”

  • The paper relies on this without support.

    Natural behaviors performed by individuals are the appropriate target for understanding neural mechanisms of behavior.

    “Understanding behavior and its component processes at the level of detail necessary to generate meaningful neural level insights will require an emphasis on natural behaviors performed by individuals.”

  • The paper relies on this without support.

    The current dominant notion of what constitutes understanding in neuroscience is based on an interventionist approach to causality.

    “The current dominant notion of what constitutes understanding in neuroscience is based on an interventionist approach to causality.”

  • The paper relies on this without support.

    Neuroscience has been focused of late on neural circuits.

    “Neuroscience has been focused of late on neural circuits.”

  • The authors state this as an assumption.

    There is an implicit assumption in neuroscience that implementation-level description will not only allow causal claims but also somehow lead to algorithmic and computational understanding (naive emergence).

    “There seems to be an implicit assumption that implementation-level description will not only allow causal claims but also somehow lead to algorithmic and computational understanding (''naive'' emergence).”
6 of 6

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Reductionist behavioral tests, though more controllable, raise questions regarding translatability; if a task is far enough removed from an animal's natural environment or behavioral repertoire, it may reflect neural or behavioral responses not used naturally.

    “Though the widely used reductionist tests have the advantage of better controllability, they still raise questions regarding translatability—if a behavioral task is far enough removed from an animal’s natural environment or behavioral repertoire, it may reflect neural or behavioral responses that are not used naturally (Krakauer et al., 2017).”

    From Wireless Optogenetic Stimulation of Oxytocin Neurons in a Semi-natural Setup Dynamically Elevates Both Pro-social and Agonistic Behaviors (2020) · cites this paper as Krakauer et al., 2017

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Related

Authors
Krakauer, J. W., Ghazanfar, A. A., Gomez-Marin, A., MacIver, M. A., & Poeppel, D.
Affiliations
  • Johns Hopkins University (US)
  • Princeton University (US)
  • Northwestern University (US)
  • Max Planck Institute for Empirical Aesthetics (DE)
Corresponding author
Krakauer, John W.
ORCID
Venue
Neuron
Publisher
Elsevier BV
Published
2017-02
Volume
93
Issue
3
Pages
480-490
ISSN
0896-6273 (ISSN-L)
DOI
10.1016/j.neuron.2016.12.041
OpenAlex
W2586907386
Cited by
1,358
References
71
Citations by year
2026: 113 · 2025: 142 · 2024: 148 · 2023: 143 · 2022: 156 · 2021: 181 · 2020: 131 · 2019: 172 · 2018: 123 · 2017: 48
FWCI
67.33
Type
journal article
Language
en
Open access
Licence
Locations
  • Neuron (publishedVersion)
  • PubMed (publishedVersion)
  • DIGITAL.CSIC (Spanish National Research Council (CSIC)) (submittedVersion)
  • MPG.PuRe (Max Planck Society) (submittedVersion)
Topics
  • Social Sciences › Arts and Humanities › History and Philosophy of Science › Philosophy and History of Science
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Undergraduate Neuroscience Education and Research
  • Social Sciences › Psychology › Experimental and Cognitive Psychology › Philosophy and Theoretical Science
Keywords
reductionism, brain-behavior relationship, psychobiology, neural manipulation, causal explanation, necessity and sufficiency, task analysis, component processes, philosophy of neuroscience
MeSH terms
Algorithms, Animals, Behavior, Brain, Humans, Neurosciences, Task Performance and Analysis, Bias

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