Week 12: Functional Divisions of Mental Simulation
🎯 Learning Goal
Explain the functional divisions of “David’s Integrated Neural System for Mental Simulation.”
📚 Core Concepts
Professor Havas’ Integrated Neural System for Mental Simulation breaks down how the brain simulates actions and outcomes using distinct but interconnected systems:
• Perception–Action Cycle:
Every perception leads to an action, and every action leads to a new perception. This cycle allows the brain to continuously update its internal model of the world.
Motor Cortex Hierarchy:
SMA (Supplementary Motor Area): Forms intentions and abstract action plans.
PM (Premotor Cortex): Specifies and selects action sequences.
M1 (Primary Motor Cortex): Executes fine motor movements.
“Actions are planned with respect to a goal… and unfold through a hierarchy of motor areas.” — Week 12 Motor Cognition Lecture
• Mirror Neuron System:
Observing others’ actions activates the same motor areas in the observer’s brain, enabling simulation, empathy, and social understanding.
Internal vs. External Information Streams:
External: Affordances — objects automatically suggest possible actions (e.g., a chair affords sitting).
Internal: Goals, memories, and emotional states influence whether or how we act.
🔬 Evidence from Research
• Lecture Insight:
The brain is a prediction machine. It learns the structure of the world from the bottom up and uses top-down projections to simulate what will happen next.
“The brain’s predictions are corrected by the world… and the brain learns from its mistakes.” — Week 12 Motor Cognition Lecture
• Saygin et al. (2004):
Even simplified point-light animations of human motion activate the premotor cortex, showing that the brain simulates actions even when visual input is minimal.
“These stimuli can also recruit action observation networks… characterized by motion cues alone.” — Saygin et al., 2004
• TED Talk (Biological Motion):
Point-light walkers reveal how we extract rich social and emotional information from motion alone — gender, emotion, even personality traits.
“There’s lots of information we can retrieve from the way someone moves.” — Biomotion Lab
🧩 Integration & Synthesis
This system supports predictive coding: the brain constantly simulates what will happen next based on past experience. The SMA, PM, and M1 form a functional hierarchy that allows us to mentally rehearse actions before we perform them.
The mirror neuron system allows us to simulate others’ actions, which supports empathy, language comprehension, and social cognition. This is why we flinch when we see someone else get hurt — our motor system simulates their experience.
Example: Seeing a cup of coffee activates motor plans for grasping — even if we don’t act. Example: A mug with a handle affords grasping — its shape and orientation suggest how to interact with it. But whether we actually reach for it depends on internal factors like thirst, memory of its contents, or social context (e.g., “Is this my mug?”). Example: Watching someone kick a ball activates our own motor cortex as if we were kicking.
🎨 Visuals
“The motor system is organized from intention (SMA) to execution (M1).”
“Perception and action form a continuous loop of simulation and feedback.”
“Even minimal motion cues activate motor simulation areas.”














