Foundations of Social, Cognitive, and Affective Neuroscience

PSY 511.001 Spr 2026

Rick Gilmore

Department of Psychology

Overview

Prelude

– melodysheep (2011)

If understanding everything we need to know about the brain is a mile, how far have we walked?

– National Geographic (2014)

Today’s topics

  • Why neuroscience psychology is harder than physics
  • Course overview
  • Does neuroscience need behavior? Does behavioral science need the brain?

Why psychology is harder than physics

Physics perspective

  • Simplifying assumptions
  • Universal laws
  • Macro phenomena
  • Low dimensional state space

On state spaces…

State space is the set of all possible states of a dynamical system; each state of the system corresponds to a unique point in the state space. For example, the state of an idealized pendulum is uniquely defined by its angle and angular velocity…

– Terman & Izhikevich (2008)

Figure 1 from Terman & Izhikevich (2008)

Figure 1 from Terman & Izhikevich (2008)

Psychological perspective

  • What is the state…
    • Of the world (\(W\))?
    • Of the organism?
      • Body (\(B\))
      • Nervous system (\(N\))
      • Mind (\(M\))
  • How do these states change over time?
  • What causes the changes?

flowchart TD
  N[**N**ervous System] --> B[**B**ody]
  B --> W[**W**orld]
  W --> B
  B --> N
  M["**M**ind"] -.- N

Swanson (2005) Figure 1

Swanson (2005) Figure 1

States high dimensional

  • ~86 billion neurons
  • ~100 trillion - 1 quadrillion synapses
  • ?? # of motor units
  • 600+ skeletal muscles; 300+ joints

Sejnowski, Churchland, & Movshon (2014) Figure 1

Sejnowski et al. (2014) Figure 1

Direct vs. indirect measurement

  • \(W\), \(B\), \(N\) (more or less) directly
  • vs. \(M\), measured indirectly
    • Via \(N\), \(B\), \(W\)

Your turn

  • Do you agree or disagree?
  • Does it matter?

Hard to simplify

A GIF of a spherical cow.
By Keenan Crane; (The source material is licensed under CC0), CC BY-SA 4.0

Single parts -> multiple functions

Calabrese (2018)

Calabrese (2018)
  • Many circuit wiring patterns yield similar dynamics
  • Wiring diagram (i.e., connectome) important, but not definitive

Biological systems not “designed”

  • …like human-engineered ones

https://en.wikipedia.org/wiki/Computer_architecture

https://en.wikipedia.org/wiki/Computer_architecture

Studying such systems is hard because…

  • Change structure/function over time
  • Hard to measure what is being exchanged, what is being controlled

(Cisek, 2019, fig. 3). Schematic behavioral control systems. (A) When the current nutrient state deviates from a desired state, locomotion is initiated, ultimately bringing the animal to a more desirable state. (B) Elaboration of nutrient state control into a high-level controller (ANS) and a lower-level controller (BNS) capable of two modes of locomotion, local exploitation, and long-range exploration. 5HT, serotonin; ANS/BNS, apical/blastoporal nervous system; DA, dopamine; NPY, neuropeptide Y

(Cisek, 2019, fig. 3). Schematic behavioral control systems. (A) When the current nutrient state deviates from a desired state, locomotion is initiated, ultimately bringing the animal to a more desirable state. (B) Elaboration of nutrient state control into a high-level controller (ANS) and a lower-level controller (BNS) capable of two modes of locomotion, local exploitation, and long-range exploration. 5HT, serotonin; ANS/BNS, apical/blastoporal nervous system; DA, dopamine; NPY, neuropeptide Y

Course overview

Goals

  • Master fundamentals of neuroscientific concepts and facts
  • Prepare to read primary source literature in social, behavioral, cognitive, affective, and clinical neuroscience

Structure

https://psu-psychology.github.io/psy-511-scan-fdns-2026-spring/

Questions

  • What is the basic organizational plan of the nervous system?
  • How does the nervous system undergird…
    • action
    • perception
    • emotion
    • learning & memory

Questions

  • What happens to the brain during sleep?
  • How does the nervous system develop? How has it evolved?
  • How do neurons work? How do they communicate?
  • How do disorders of the mind reveal themselves in the nervous system?

Approach

  • Biologically essential behaviors
  • Brain architecture (neuroanatomy)
  • Brain function (neurophysiology)
  • Brain communication (neurochemistry)
  • Changes over evolutionary and developmental time

Approach

  • The nervous system as a mechanism
  • Specifically, an information processing system

Wikipedia

Wikipedia

Mindful of limitations in brain/computer metaphors

https://www.explainthatstuff.com/howcomputerswork.html

https://www.explainthatstuff.com/howcomputerswork.html

Inputs

  • From environment, body, brain

Processing

  • Current inputs + brain state + body state + possible future states…
  • Stored information
  • Physiological & behavioral goals

Cisek (2019) Figure 1

Cisek (2019) Figure 1

Outputs

  • To brain, body, environment

Mapping structures to functions…

Cisek (2019) Figure 8

Cisek (2019) Figure 8

And vice versa?

Cepelewicz (2021)

Cepelewicz (2021)

The brainwide representation of behavioral variables suggests that information encoded nearly anywhere in the forebrain is combined with behavioral state variables into a mixed representation…Our data indicate that it happens as early as primary sensory cortex.

– Stringer et al. (2019)

Do we have the right “psychological” structures?

Psychological sciences have identified a wealth of cognitive processes and behavioral phenomena, yet struggle to produce cumulative knowledge…

– Eisenberg et al. (2019)

Progress is hamstrung by siloed scientific traditions and a focus on explanation over prediction…two issues that are particularly damaging for the study of multifaceted constructs like self-regulation…We conclude that self-regulation lacks coherence as a construct…

– Eisenberg et al. (2019)

How should behavior be defined?

How is behaviour defined?

Behavioural biology is a major discipline within biology, centred on the key concept of ‘behaviour’. But how is ‘behaviour’ defined, and how should it be defined? …

– Levitis, Lidicker, & Freund (2009)

We outline what characteristics we believe a scientific definition should have, and why we think it is important that a definition have these traits. We then examine the range of available published definitions for behaviour.

– Levitis et al. (2009)

Finding no consensus, we present survey responses from 174 members of three behaviour-focused scientific societies as to their understanding of the term. Here again, we find surprisingly widespread disagreement as to what qualifies as behaviour…

– Levitis et al. (2009)

Respondents contradict themselves, each other, and published definitions, indicating that they are using individually variable intuitive, rather than codified, meanings of `behaviour.’

– Levitis et al. (2009)

We offer a new definition, based largely on survey responses: “Behaviour is the internally coordinated responses (actions or inactions) of whole living organisms (individuals or groups) to internal and/or external stimuli, excluding responses more easily understood as developmental changes.”

– Levitis et al. (2009)

Levels of analysis

Sejnowski et al. (2014) Figure 1

Sejnowski et al. (2014) Figure 1

David Marr (1945-1980)

David Marr

David Marr

Marr (1980)

Marr (1980)

Marr’s Three Levels

Favela (2020) Figure 3

Favela (2020) Figure 3
  • What must be computed to carry out task X?
  • What algorithm is used to carry out the computation?
  • What hardware implements the algorithm?

Computational level

  • What has to be computed?
    • What is the shape/form of that unknown object?
    • What did that person just say?
    • Is that unknown object a threat to me?

Algorithmic level

  • What’s the ‘recipe’ or sequence of operations for…
    • computing shape
    • perceiving speech
    • recognizing threats

Implementation level

  • How do…
    • neurons
    • areas
    • networks
  • implement the recipe?

Causality in neuroscience

  • Siddiqi, Kording, Parvizi, & Fox (2022)
  • Stimulation & lesion studies needed for inferring causation.
  • Bradford-Hill criteria (Hill, 2015)

Varied notions of mechanism

Fig. 1: The narrow and broad notions of mechanism from Ross & Bassett (2024)

Fig. 1: The narrow and broad notions of mechanism from Ross & Bassett (2024)

Toward reverse neuroethology

Figure 1 from Asinof & Card (2024)

Figure 1 from Asinof & Card (2024)

…when faced with a difficult question, we often answer an easier one instead, usually without noticing the substitution.

– Kahneman (2013), p. 12 quoted in Krakauer, Ghazanfar, Gomez-Marin, MacIver, & Poeppel (2017)

There and back again

  • The perception action-cycle

Fuster (2004) Figure 2

Fuster (2004) Figure 2

Another example…

flowchart LR
  A["Screen"] --> B(("Retina"))
  B --> C["Thalamus"]
  C --> D["Primary visual cortex"]
  D --> E["?"]
Figure 1: From computer screen to cortex. 
flowchart LR
  E["?"] --> F["Primary motor cortex"]
  F --> G("Motor neuron")
  G -->|"Alpha motor fiber"|H(["Extrafusal muscle fiber"])
  G --> I("Spinal interneuron")
  I -->|"Gamma motor fiber"|J(["Intrafusal fiber"])
  H & J --> K(["Finger muscle"])
Figure 2: Pathways to move the finger. 
flowchart LR
  A(["Finger muscle"]) --> C(["Intrafusal muscle fiber"])
  C --> D["Stretch receptor"]
  D -->|"Ia afferent"| E("Spinal cord interneuron")
  E --> F["Somatosensory cortex"]
Figure 3: Feedback from finger muscle. 
flowchart LR
  A["Finger skin"] --> B("Spinal cord neuron")
  B --> C["Somatosensory cortex"]
  D["Finger joints"] --> B
Figure 4: Other sources of sensory information from the finger. 
flowchart LR
  A["Finger skin"] --> B["Somatosensory cortex"]
  C["Finger joints"] --> B
  D["Stretch receptor"] --> B
  E["Motor cortex"] --> B
  F["?"] --> B
Figure 5: Inputs to primary somatosensory cortex.

Break

Your turn

Does neuroscience need behavior?

Krakauer, J. W., Ghazanfar, A. A., Gomez-Marin, A., MacIver, M. A., & Poeppel, D. (2017). Neuroscience needs behavior: Correcting a reductionist bias. Neuron, 93(3), 480–490. https://dx.doi.org/10.1016/j.neuron.2016.12.041.

Parada, F. J. & Rossi, A. (2018). If neuroscience needs behavior, what does psychology need? Frontiers in Psychology, 9, 433. https://doi.org/10.3389/fpsyg.2018.00433.

Newcombe, N. (2017). If neuroscience needs behavior, what does behavioral science need? APS Observer, 31(1). https://www.psychologicalscience.org/observer/if-neuroscience-needs-behavior-what-does-behavioral-science-need

Key points

  • Questions ‘often tacit…belief in the reductionist program for understanding the link between brain and behavior’
  • Behavior -> understanding; neural interventions -> causality
  • Marr’s 3 levels (computation; algorithm; implementation)

But what is behavior?

“Behavioural biologists don’t agree on what constitutes behaviour”

Behaviour is the internally coordinated responses (actions or inactions) of whole living organisms (individuals or groups) to internal and/or external stimuli, excluding responses more easily understood as developmental changes.

– Levitis et al. (2009)

Krakauer et al. (2017) Figure 1

Krakauer et al. (2017) Figure 1

Krakauer et al. (2017) Figure 2

Krakauer et al. (2017) Figure 2

Krakauer et al. (2017) Figure 3

Krakauer et al. (2017) Figure 3

Krakauer et al. (2017) Figure 4

Krakauer et al. (2017) Figure 4

Parada & Rossi (2018) Figure 1

Parada & Rossi (2018) Figure 1

Exercise LVL

Main points

  • Psychology is harder than physics
  • Neuroscience needs behavior
  • Psychology needs behavior + mental states + measures of environment

Next time…

Resources

References

Asinof, S. K., & Card, G. M. (2024). Neural control of naturalistic behavior choices. Annual Review of Neuroscience, 47, 369–388. https://doi.org/10.1146/annurev-neuro-111020-094019
Calabrese, R. L. (2018). Inconvenient truth to principle of neuroscience. Trends in Neurosciences, 41(8), 488–491. https://doi.org/10.1016/j.tins.2018.05.006
Cepelewicz, J. (2021, August). Mental phenomena don’t map into the brain as expected. https://www.quantamagazine.org/mental-phenomena-dont-map-into-the-brain-as-expected-20210824/. Retrieved from https://www.quantamagazine.org/mental-phenomena-dont-map-into-the-brain-as-expected-20210824/
Cisek, P. (2019). Resynthesizing behavior through phylogenetic refinement. Attention, Perception & Psychophysics. https://doi.org/10.3758/s13414-019-01760-1
Eisenberg, I. W., Bissett, P. G., Zeynep Enkavi, A., Li, J., MacKinnon, D. P., Marsch, L. A., & Poldrack, R. A. (2019). Uncovering the structure of self-regulation through data-driven ontology discovery. Nature Communications, 10(1), 2319. https://doi.org/10.1038/s41467-019-10301-1
Favela, L. H. (2020). Cognitive science as complexity science. Wiley Interdisciplinary Reviews. Cognitive Science, 11(4), e1525. https://doi.org/10.1002/wcs.1525
Fuster, J. M. (2004). Upper processing stages of the perception-action cycle. Trends in Cognitive Sciences, 8, 143–145. https://doi.org/10.1016/j.tics.2004.02.004
Hill, A. B. (2015). The environment and disease: Association or causation? 1965. Journal of the Royal Society of Medicine, 108(1), 32–37. https://doi.org/10.1177/0141076814562718
Kahneman, D. (2013). Thinking, fast and slow (1st edition). Farrar, Straus; Giroux. Retrieved from https://www.amazon.com/Thinking-Fast-Slow-Daniel-Kahneman/dp/0374533555
Krakauer, J. W., Ghazanfar, A. A., Gomez-Marin, A., MacIver, M. A., & Poeppel, D. (2017). Neuroscience needs behavior: Correcting a reductionist bias. Neuron, 93(3), 480–490. https://doi.org/10.1016/j.neuron.2016.12.041
Levitis, D. A., Lidicker, W. Z., & Freund, G. (2009). Behavioural biologists don’t agree on what constitutes behaviour. Animal Behaviour, 78(1), 103–110. https://doi.org/10.1016/j.anbehav.2009.03.018
Marr, D. (1980). Vision. Retrieved from https://mitpress.mit.edu/books/vision
melodysheep. (2011, March). Ode to the brain! By symphony of science. Youtube. Retrieved from https://www.youtube.com/watch?v=JB7jSFeVz1U
National Geographic. (2014, January). Beautiful 3-D brain scans show every synapse | national geographic. YouTube. Retrieved from https://www.youtube.com/watch?v=nvXuq9jRWKE
Parada, F. J., & Rossi, A. (2018). If neuroscience needs behavior, what does psychology need? Frontiers in Psychology, 9, 433. https://doi.org/10.3389/fpsyg.2018.00433
Ross, L. N., & Bassett, D. S. (2024). Causation in neuroscience: Keeping mechanism meaningful. Nature Reviews. Neuroscience. https://doi.org/10.1038/s41583-023-00778-7
Sejnowski, T. J., Churchland, P. S., & Movshon, J. A. (2014). Putting big data to good use in neuroscience. Nat. Neurosci., 17(11), 1440–1441. https://doi.org/10.1038/nn.3839
Siddiqi, S. H., Kording, K. P., Parvizi, J., & Fox, M. D. (2022). Causal mapping of human brain function. Nature Reviews Neuroscience, 23(6), 361–375. https://doi.org/10.1038/s41583-022-00583-8
Stringer, C., Pachitariu, M., Steinmetz, N., Reddy, C. B., Carandini, M., & Harris, K. D. (2019). Spontaneous behaviors drive multidimensional, brainwide activity. Science, 364(6437), 255. https://doi.org/10.1126/science.aav7893
Swanson, L. W. (2005). Anatomy of the soul as reflected in the cerebral hemispheres: Neural circuits underlying voluntary control of basic motivated behaviors. Journal of Comparative Neurology, 493(1), 122–131. https://doi.org/10.1002/cne.20733
Terman, D., & Izhikevich, E. (2008). State space. Scholarpedia Journal, 3, 1924. https://doi.org/10.4249/scholarpedia.1924