The Brain as the Seat of the Mind
Biological Psychology (or behavioral neuroscience) investigates the physiological and neural mechanisms of behavior. One of its founding debates concerned the timing and cause of emotion. William James and Carl Lange independently proposed the James-Lange theory: physiological arousal comes first, and the SUBJECTIVE feeling of emotion follows as the brain's interpretation of that bodily state — we feel afraid because we notice ourselves trembling, not the reverse. Walter Cannon and Philip Bard challenged this with the Cannon-Bard theory: physiological arousal and the subjective experience of emotion occur simultaneously and somewhat independently, both triggered together by the thalamus relaying signals to the cortex and the body at once.
Meanwhile, Karl Lashley searched for the engram — the physical trace of a memory in the brain — by training rats on a maze task and then surgically removing varying amounts of cortical tissue. He found that memory loss depended more on how much cortex was removed than on precisely which region, leading him to propose two principles: mass action (the cortex functions as an integrated whole for complex tasks) and equipotentiality (many regions of a functional area can substitute for one another after damage). Lashley never found a single, localized engram.
| Theory | Order of events |
|---|---|
| James-Lange | Arousal first, then subjective emotion |
| Cannon-Bard | Arousal and emotion simultaneously, both from the thalamus |
Later, Donald Hebb proposed a cellular mechanism for how experience changes the brain: "cells that fire together, wire together," now known as Hebbian learning — repeated co-activation of two neurons strengthens the synaptic connection between them, providing a physical basis for how the engram Lashley searched for might actually be stored, distributed across many strengthened connections rather than any single site.
Common pitfall: assuming Lashley's failure to find a single engram meant memory has no physical basis at all. His conclusion was the opposite — memory has a distributed physical basis across many cortical regions working together, not a localized one.