How Do Brain and Body Support Mind and Behavior?

From explanatory questions and neural networks to plasticity, regulation, reward, and awareness.

Level: Introductory
Reading load: 11 core readings in 6 units
Prerequisites: No neuroscience course is assumed. The guides introduce essential biological and methodological terms; several reviews will reward more than one sitting. How to Read Psychological Science offers useful preparation in evaluating evidence, but is not a prerequisite.
Last reviewed: September 2026

Introduction

The brain belongs to the world it helps us know. To explain a memory, a pleasure, or a movement, we must follow the relations between nervous tissue, the living body, and its surroundings. Naming a region gives us a place to begin; understanding requires evidence of what happens there and how it contributes to the capacity we wish to explain.

This path moves from explanatory frameworks to cells and networks, then examines how experience changes nervous systems and how brain and body regulate one another. Reward, sleep, and disorders of consciousness make the distinctions between a psychological capacity, a biological mechanism, and its measurement concrete. Conceptual reviews supply ways of thinking; empirical papers give you opportunities to use them.

By the end, you should be able to distinguish questions about how a capacity works, how it develops, what it does for the organism, and how it arose through evolution; connect a measure with the inference it supports; and compare human observations with biological interventions and animal evidence. Keep a running example—a remembered event, a sought reward, or a change in alertness—and ask how each unit changes what an adequate explanation would require.

Unit 1 of 6

What would count as a biological explanation?

Begin by separating the questions an explanation might answer. Then examine a common inferential shortcut: assuming that activity in a region identifies a mental process. The framework clarifies the target; the methodological paper clarifies what one kind of evidence can contribute.

Reading
1 of 11
Tinbergen's Four Questions: An Appreciation and an Update
Bateson, P., & Laland, K. N. (2013). Tinbergen's four questions: An appreciation and an update. Trends in Ecology & Evolution, 28(12), 712–718. https://doi.org/10.1016/j.tree.2013.09.013
Major synthesis · Contemporary update · Moderate · Full work: 7 pages
Use the four questions to keep mechanism, development, current utility, and evolutionary history distinct.
Why you’re reading it. This framework will help you recognize what each later biological explanation addresses and what it leaves open.
A question to consider. For a person learning to juggle, formulate one question of each kind. Which could repeated brain scans help answer?
Reading
2 of 11
Can Cognitive Processes Be Inferred from Neuroimaging Data?
Poldrack, R. A. (2006). Can cognitive processes be inferred from neuroimaging data? Trends in Cognitive Sciences, 10(2), 59–63. https://doi.org/10.1016/j.tics.2005.12.004
Methodological contribution · Critical reappraisal · Moderate · Full work: 5 pages
Follow why knowing that a region is active during a task is different from identifying the process occurring whenever that region is active.
Why you’re reading it. Establish a standard for interpreting the neural measurements encountered throughout this path.
A question to consider. A news report says a reward-related region activated while someone viewed a photograph, so the person must have enjoyed it. What comparison and background information are missing?

Unit 2 of 6

How do cells and networks support a capacity?

A psychological capacity depends on organized activity, not merely a list of locations. Yuste argues for considering populations of interacting cells. Scoville and Milner provide a different route to explanation: examining what is impaired and preserved after damage. Neither approach alone supplies the complete mechanism.

A network account asks how cells influence one another and how their coordinated activity contributes to a capacity. Begin by explaining that proposal in words. Then ask what evidence could distinguish it from an account based on the response of one cell or region.

Reading
3 of 11
From the Neuron Doctrine to Neural Networks
Yuste, R. (2015). From the neuron doctrine to neural networks. Nature Reviews Neuroscience, 16(8), 487–497. https://doi.org/10.1038/nrn3962
Foundational argument · Major synthesis · Challenging · Full work: 11 pages
Compare explanations based on a cell's response with explanations based on interactions and population activity.
Why you’re reading it. Build a vocabulary for organization between the level of individual neurons and the level of behavior.
A question to consider. Explain how interactions among cells could matter to remembering even when no single cell's response explains the whole capacity. What observation would help evaluate that account?
Reading
4 of 11
Loss of Recent Memory after Bilateral Hippocampal Lesions
Scoville, W. B., & Milner, B. (1957). Loss of recent memory after bilateral hippocampal lesions. Journal of Neurology, Neurosurgery & Psychiatry, 20(1), 11–21. https://doi.org/10.1136/jnnp.20.1.11
Landmark empirical study · Historical turning point · Moderate · Full work: 11 pages
Compare the affected tissue and the pattern of impaired and preserved performance across the reported cases.
Why you’re reading it. Contrast evidence from damage with evidence from activation, while retaining the network perspective.
A question to consider. If damage disrupts a capacity, what further evidence would show whether the tissue stores its information, coordinates other regions, or supports another necessary process?

Unit 3 of 6

How does experience change a nervous system?

Organization is itself a developmental achievement. The review describes several forms of neural change and their dependence on timing and conditions. The juggling study then asks what an anatomical measure can reveal about a particular experience. Keep the biological scale of the explanation aligned with the scale of the evidence.

Reading
5 of 11
Brain Plasticity and Behaviour in the Developing Brain
Kolb, B., & Gibb, R. (2011). Brain plasticity and behaviour in the developing brain. Journal of the Canadian Academy of Child and Adolescent Psychiatry, 20(4), 265–276.
Major synthesis · Moderate · Full work: 12 pages
Track which processes change, at what age, and in which species, rather than treating plasticity as one quantity.
Why you’re reading it. Connect developmental explanation with mechanisms that can alter neural organization.
A question to consider. Two experiences produce opposite changes in a synaptic measure but both improve performance. Why would that challenge a simple ‘more is better’ interpretation?
Reading
6 of 11
Changes in Grey Matter Induced by Training
Draganski, B., Gaser, C., Busch, V., Schuierer, G., Bogdahn, U., & May, A. (2004). Changes in grey matter induced by training. Nature, 427(6972), 311–312. https://doi.org/10.1038/427311a
Landmark empirical study · Accessible · Full work: 2 pages
Connect the training schedule and comparison group with the changing MRI measure.
Why you’re reading it. Apply the review's distinctions to a concise human study without turning a structural observation into an unsupported cellular explanation.
A question to consider. A headline says juggling grows new neurons. Which additional measurement would be needed before that interpretation followed from these results?

Unit 4 of 6

How do brain and body regulate each other?

A nervous system functions within a body and an environment. McEwen's account connects interpretation, physiological responses, and recovery. Cohen and colleagues put part of this broad question into a controlled exposure setting, allowing a close examination of what was controlled, what was measured, and which mechanism remains uncertain.

Reading
7 of 11
Protective and Damaging Effects of Stress Mediators: Central Role of the Brain
McEwen, B. S. (2006). Protective and damaging effects of stress mediators: Central role of the brain. Dialogues in Clinical Neuroscience, 8(4), 367–381. https://doi.org/10.31887/DCNS.2006.8.4/bmcewen
Major synthesis · Foundational argument · Challenging · Full work: 15 pages
Follow the feedback between brain and body and the distinction between an adaptive response and its cumulative costs.
Why you’re reading it. Broaden biological explanation beyond neural location to interacting regulatory systems over time.
A question to consider. How would you distinguish repeated short responses with recovery from one prolonged response if both produced the same average hormone level?
Reading
8 of 11
Psychological Stress and Susceptibility to the Common Cold
Cohen, S., Tyrrell, D. A. J., & Smith, A. P. (1991). Psychological stress and susceptibility to the common cold. New England Journal of Medicine, 325(9), 606–612. https://doi.org/10.1056/NEJM199108293250903
Landmark empirical study · Moderate · Full work: 7 pages
Separate standardized viral exposure, measured stress, infection, and clinical illness.
Why you’re reading it. Evaluate a brain–body claim using biological outcomes and design features beyond imaging.
A question to consider. Which part of McEwen's proposed pathway does this design bear on, and what would still be needed to identify the mediator and causal direction?

Unit 5 of 6

What exactly changes when reward changes?

A biological explanation needs a sufficiently precise psychological target. Reward seeking, pleasure, and learning often occur together; they need not change together. This unit asks how separating those components changes the interpretation of a neural intervention.

Reading
9 of 11
Parsing Reward
Berridge, K. C., & Robinson, T. E. (2003). Parsing reward. Trends in Neurosciences, 26(9), 507–513. https://doi.org/10.1016/S0166-2236(03)00233-9
Foundational argument · Major synthesis · Moderate · Full work: 7 pages
Compare the measures and interventions used to distinguish learning, ‘wanting,’ and ‘liking.’
Why you’re reading it. See why careful psychological definitions remain necessary when studying molecules and circuits.
A question to consider. An intervention increases reward seeking without changing pleasurable reactions. How would you interpret the result, and which alternative explanations would you test?

Unit 6 of 6

What changes across sleep, waking, and awareness?

Biological state affects both performance and the evidence we can obtain about it. The sleep model separates regulatory influences that can be tested against a time course. The consciousness study examines evidence of command following when overt responses are limited. Explaining when sleep occurs and detecting awareness are different questions; bringing them together prevents wakefulness, responsiveness, and experience from being treated as interchangeable.

Reading
10 of 11
The Two-Process Model of Sleep Regulation: A Reappraisal
Borbély, A. A., Daan, S., Wirz-Justice, A., & Deboer, T. (2016). The two-process model of sleep regulation: A reappraisal. Journal of Sleep Research, 25(2), 131–143. https://doi.org/10.1111/jsr.12371
Major synthesis · Critical reappraisal · Challenging · Full work: 13 pages
Keep sleep pressure, circadian timing, and their observable markers distinct.
Why you’re reading it. Evaluate a model that predicts change over time and is revised when its assumptions meet new evidence.
A question to consider. How would changing sleep timing help separate effects of prior wakefulness from effects of the biological clock?
Reading
11 of 11
Willful Modulation of Brain Activity in Disorders of Consciousness
Monti, M. M., Vanhaudenhuyse, A., Coleman, M. R., Boly, M., Pickard, J. D., Tshibanda, L., Owen, A. M., & Laureys, S. (2010). Willful modulation of brain activity in disorders of consciousness. New England Journal of Medicine, 362(7), 579–589. https://doi.org/10.1056/NEJMoa0905370
Landmark empirical study · Methodological contribution · Moderate · Full work: 11 pages
Trace the evidence from an instruction to a task-specific signal, and compare that positive result with the reasons a signal may be absent.
Why you’re reading it. Bring together measurement, functional inference, and state dependence in a case where the limits of an inference matter greatly.
A question to consider. Why does this command-following design support a stronger inference than merely observing activity in a region associated with awareness, while still leaving a negative result ambiguous?

Scope and omissions

This is a foundation in biological explanation, not a survey of every brain region or a training course in neuroscience methods. It includes human imaging, clinical lesion evidence, controlled viral exposure, animal experiments synthesized in reviews, and conceptual models. These sources represent selected organisms and participants, not all populations or conditions.

Detailed electrophysiology, sensory and motor circuits, molecular genetics, reproductive endocrinology, and pharmacology require more room than this route allows. Evolution supplies an explanatory framework here rather than a full comparative evidence sequence. Reward is one entry to motivation and affect, not a complete theory of emotion. Sleep regulation and detected command following likewise do not settle sleep's functions or competing theories of consciousness. Clinical examples teach inference; they do not provide individual diagnosis or treatment advice.

Synthesis

Biological explanation gains its force by connecting levels of life. Cells act within circuits; circuits develop within bodies; bodies meet an environment they must continually respond to. The connections become intelligible when the question and the evidence fit. Learning, pleasure, and motivation need distinct measures, as do sleep timing, responsiveness, and awareness: a common biological setting does not make them the same phenomenon.

The methods also constrain the answer. Activation can inform an inference without uniquely identifying a process. Damage can reveal a necessary contribution without locating an entire capacity. A training-related image change does not identify its microscopic basis, and controlled exposure does not turn a measured psychological difference into a randomized cause. These limits point toward more precise comparisons rather than making biological explanation impossible.

Return to your running example. State the phenomenon, pose one mechanistic and one developmental question, and propose a measurement and an intervention that would distinguish plausible accounts. Then identify what evidence would still be needed about current utility or evolutionary history.

To develop the connection between neural activity and behavior, continue with How Do Neural Circuits Turn Sensation into Action?. It follows signals within and between cells through sensory selection and movement, then examines what circuit interventions can establish.

For a closer look at memory, choose How Do We Remember—and Why Do We Forget? to connect lesion evidence with accounts of memory organization and change.