Newspaper Zombie
Field note
Field note. Subject walks slowly, holding a newspaper in front of its face, and appears calm. When the paper is destroyed, it shows an abrupt rage response and roughly doubles its speed. After losing its head, it keeps walking for a moment before falling.
Predict first
Review the field notes and then consider how to explain the zombie’s behavior.
Is this zombie really reading? And why does losing the paper make it so angry? Make a guess, then open the report.
Scans
AI-drawn image. Not yet checked by an expert; may contain anatomical errors and, obviously, is not detailed enough to be accurate.
Region guide
- Cerebral cortex
- The brain’s wrinkled outer layer. Handles higher functions such as thinking, language, and perception; the prefrontal cortex is one part of it.
- Prefrontal cortex
- The front of the frontal lobe. Supports planning and higher-level thinking.
- Amygdala
- A small, almond-shaped area deep in the temporal lobe. Processes emotion, especially fear and aggression.
- Hippocampus
- A curved structure deep in the temporal lobe. Helps form new memories of facts and events.
- Basal ganglia
- A group of structures deep in the brain. Help control movement and form habits.
- Corpus callosum
- A thick band of nerve fibers connecting the left and right halves (hemispheres) of the brain so they can share information.
- Cerebellum
- At the back, below the cortex. Controls balance and coordination; helps with skills and habits.
- Thalamus
- The brain’s sensory relay station. Passes along information from every sense except smell.
- Hypothalamus
- Below the thalamus. Keeps the body in balance (temperature, appetite) and helps trigger fight or flight.
- Pituitary gland
- A pea-sized gland hanging below the hypothalamus, which controls it. Called the “master gland” because its hormones direct many other glands in the body.
- Brainstem
- Connects the brain to the spinal cord. Runs automatic functions such as breathing and heart rate.
- Pons
- Part of the brainstem. Connects the lower brainstem and cerebellum with the rest of the brain and helps regulate brain activity during sleep.
- Spinal cord
- Not part of the brain. Carries messages between the brain and body and runs some reflexes on its own.
Sources: Spielman et al. (2020), §3.4, §3.5, §8.2, §10.4; basal ganglia from Cleveland Clinic (2022). (Unchecked by a person; AI research only.)
Brain report
(open it after you make your guess)
What’s different. This zombie has a smaller prefrontal cortex and hippocampus than the control brain and a larger amygdala, and all three look damaged. Its basal ganglia, cerebellum, and brainstem look typical, and its spinal cord is unusually thick.
Is it reading? Probably not. We think this zombie holds the newspaper out of habit. Habits and skills are a kind of implicit memory: you use them without consciously remembering them, like riding a bike (Spielman et al., 2020, §8.1). (Unchecked by a person; AI research only.) The cerebellum supports this kind of memory (Spielman et al., 2020, §8.2), and so do the basal ganglia (Knowlton et al., 1996). (Unchecked by a person; AI research only.) Both look typical here. The hippocampus, which helps form new memories of facts and events, is smaller (Spielman et al., 2020, §8.2). (Unchecked by a person; AI research only.) This zombie might not be able to tell you what it just “read.”
A real-life comparison. After surgery removed his hippocampus, patient H.M. could no longer form many new memories of facts and events, but he could still learn new motor skills (Spielman et al., 2020, §3.4). (Unchecked by a person; AI research only.)
Why the sudden rage? The amygdala processes emotion, especially fear and aggression. Sensory information can reach it by a fast route straight from the thalamus, before the cortex has a chance to weigh in (Spielman et al., 2020, §10.4). (Unchecked by a person; AI research only.) The prefrontal cortex helps people calm themselves down (Ochsner & Gross, 2005). (Unchecked by a person; AI research only.) A large amygdala and a small prefrontal cortex could add up to a short temper.
Why so fast? Strong emotion activates the body’s sympathetic nervous system (“fight or flight”), and the hypothalamus helps switch it on (Spielman et al., 2020, §10.4). (Unchecked by a person; AI research only.) That might explain the burst of speed.
How it might walk without a head. In people, the spinal cord handles some reflexes without the brain, such as pulling your hand away from something hot (Spielman et al., 2020, §3.4). (Unchecked by a person; AI research only.) Animal research suggests the spinal cord also contains circuits that can produce a basic stepping rhythm (Guertin, 2009). (Unchecked by a person; AI research only.) Like the Basic Zombie, this zombie has an extra-thick spinal cord, which might let it keep stepping for a moment after losing its brain. A human couldn’t do this.
Real-brain takeaway
- Implicit memory (habits and skills) and explicit memory (facts and events) rely on different brain areas.
- The hippocampus helps form new explicit memories.
- The amygdala processes emotion; the prefrontal cortex helps regulate it.
- The hypothalamus helps trigger the body’s fight-or-flight response.
- The spinal cord carries messages between the brain and body and runs some reflexes on its own.
Sources for this page
Guertin, P. A. (2009). The mammalian central pattern generator for locomotion. Brain Research Reviews, 62(1), 45–56. https://doi.org/10.1016/j.brainresrev.2009.08.002 (Unchecked by a person; AI research only.)
Knowlton, B. J., Mangels, J. A., & Squire, L. R. (1996). A neostriatal habit learning system in humans. Science, 273(5280), 1399–1402. https://doi.org/10.1126/science.273.5280.1399 (Unchecked by a person; AI research only.)
Ochsner, K. N., & Gross, J. J. (2005). The cognitive control of emotion. Trends in Cognitive Sciences, 9(5), 242–249. https://doi.org/10.1016/j.tics.2005.03.010 (Unchecked by a person; AI research only.)
Spielman, R. M., Jenkins, W. J., & Lovett, M. D. (2020). Psychology 2e. OpenStax. https://openstax.org/details/books/psychology-2e (Free to read) (Unchecked by a person; AI research only.)
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