PSYC74H3 - Midterm 1

Slides, Lectures, Readings; from weeks 1-4

Pythagoras

He believed the soul was a self-moving number and that the movement of the soul was connected to the motion of the planets.

Heraclitus

Reality is always changing; we can't know objects completely, only their movement paths.

Democritus

The soul moves the body through the movement of tiny particles (atoms), an early idea similar to modern ions in neurons.

Plato

Self-movement shows the soul is immortal. He compared the body to a chariot and the soul to the charioteer guiding it.

Aristotle

Movement requires both a mover (soul) and something being moved (body). Only living beings move purposefully.

Galen

Muscles work in opposing pairs, and 'animal spirits' travel through nerves to make muscles contract.

Leonardo da Vinci

Carefully studied human and animal anatomy to understand movement.

Descartes

Believed humans are made of two separate things: soul and body. Some movements, like reflexes, happen automatically without the soul.

Borelli

Used physics to explain how muscles move; muscles act like elastic fibers. He suggested a 'nerve juice' theory for muscle contraction.

Swammerdam

Experiments showed nerves cause muscles to contract directly; proved 'animal spirits' aren't liquids.

Galvani

Nerves and muscles use electricity to communicate.

Matteucci

Muscles themselves generate electrical currents.

DuBois-Reymond

First to record electrical activity in muscles (EMG).

Pflüger

Even decapitated frogs could move their legs in reflex patterns; spinal cord can produce movement without the brain.

Marey & Muybridge

Used high-speed photography to study human and animal motion; this was the start of modern motion analysis.

Helmholtz

How we see depends on both our senses and movements.

Sechenov

We actively look at things; perception is not passive.

Woodworth

Movements have an initial impulse and corrections happen later; faster movements produce more errors.

Ramón y Cajal

Nervous system made of individual neurons, not one continuous network.

Sherrington & Foster

Discovered the synapse, the gap where neurons communicate.

Babinski

Damage to the cerebellum causes poor coordination ('asynergias').

Hughlings Jackson

CNS has three levels controlling movement.

Graham Brown

Spinal cord can create rhythmic movement patterns (Central Pattern Generators) without sensory input.

Hill/Fenn/Lombard

Hill: muscles don't behave like simple springs; Fenn: more work produces more energy; Lombard paradox: muscles on both sides of a joint can contract at once.

Wachholder & Altenburger

Studied electrical activity of muscles; CNS adjusts muscle elasticity.

Gamma motoneurons

Control muscle sensors (spindles) to adjust sensitivity and precision; Merton used this to explain fine motor control.

Bernstein

Filmed fast, precise movements like piano playing at high speed to analyze them.

Levels of movement construction

Level A: Reflexes, muscle tone, posture; basic control of body. Level B: Muscle synergies and patterns; locomotion, dance; body-centered and repetitive. Level C: Goal-directed movements; adapt to environment; strategy vs result (C1 vs C2).

Level D

Meaningful, everyday actions like using tools; dominant hand faster, nondominant for stability; apraxia = can move but fail goal.

Level E

Highest human level: symbolic and cultural actions like speech, music, writing.

Motor system

Both movement + stabilization.

Example of walking

Involves stepping in a controlled way while keeping balance.

Understanding motor control

Being able to predict, control, or simulate movement.

Implicit skills

Skills like riding a bike that can be described in explicit terms for study.

Turing test for movement

Can robots move like humans?

Research focus: Learning

How do we acquire and retain skills?

Research focus: Individual differences

Genetics, experience, motivation, feedback.

Research focus: Disorders

Stroke, Parkinson's, cerebral palsy, spinal injuries.

Research focus: Rehabilitation

Restore or compensate movement.

Research focus: Robotics/AI

Replicate human movement for machines.

Applied example: Bike riding

Shows implicit skills can be analyzed explicitly.

Balance

Critical for daily life and sports.

Key historical takeaway: Motor control evolution

Evolved from philosophy → anatomy → physiology → biomechanics → neurophysiology → applied research.

Neglect of Motor Control in Psychology

Rosenbaum (2005) called motor control the 'Cinderella of psychology' because it is often ignored.

No-Celebrity Hypothesis

False; major psychologists studied motor control.

Only-Human Hypothesis

False; human motor control is not unique.

Dumb-Jock Hypothesis

False; motor activities require intelligence.

Too-Hard-to-Study Hypothesis

False; technical challenges exist but were overcome.

Think-Before-You-Act Hypothesis

Psychology prioritizes cognition; motor control is valued if linked to perception/knowledge.

Future Directions

Boundaries between psychology and neuroscience are blurring.

Degrees of Freedom Problem

Many ways to achieve a task (e.g., touching your nose). Solved using synergies (Bernstein) to coordinate muscles/joints efficiently.

Sequence & Timing Problem

How actions are ordered and timed. Errors like spoonerisms show multiple planning levels. Response chaining insufficient; hierarchical control needed (chunked sequences, rule-based).

Perceptual-Motor Integration

Movement and perception influence each other. Feedback loops: ballistic (fast) + corrective (slow). Mirror neurons link action and perception.

Learning Problem

Motor skills learned by experience, deliberate practice, specificity of practice, and neural plasticity. Example: Held & Hein (1963) kitten carousel; skill improves with repeated, targeted practice (Ericsson et al., 1993; Keetch et al., 2005; Merzenich et al., 1984).

Closed-Loop Theory

Uses feedback to refine movements; perceptual trace improves with practice; KR (knowledge of results) enhances performance; limited for complex movements.

Schema Theory

Generalized Motor Programs (GMPs) adapt to different situations; reduces stored programs while allowing consistency + novelty.

Motor Program Theory

Pre-structured commands executed without feedback; problem: feedback influences movement.

Stage Theory

1) Cognitive: verbal, high attention. 2) Associative: more automatic, experimentation. 3) Autonomous: smooth, fast, little conscious effort.

Levels of Analysis in Motor Control

Behavioral: Focus on skill learning, performance variables, cognitive processes. Biomechanical: Joints, levers, mechanical properties. Neurophysiological: Brain and CNS control of muscles. Movement depends on both motor system + environment.

Applications of Motor Control

Sports, games, rehabilitation, industrial skills, arts, and language (speech as motor task). Understanding motor control improves training, therapy, and human-machine interaction.

Historical Origins

Emerged from neurophysiology (neural mechanisms) + psychology (learning/skills). Independent until 1970s; then merging. Early philosophers: Plato, Aristotle, Galen. Early neural research: Fritsch & Hitzig (brain excitable), Sherrington (reflexes), Bernstein (degrees of freedom). Post-WWII: military research, Fleishman (motor abilities taxonomy), Fitts' law (speed-accuracy trade-off), ergonomics.

Cognitive Revolution & Integration

Shift from S-R models to cognitive/info-processing models (1970s-1990s). Schema theory (Schmidt) emphasizes generalized rules. Joint studies combine neurophysiology, biomechanics, and behavior. Dynamical systems perspective: movement emerges from body-environment interaction (Kelso, Turvey, Thelen).

Modern Research & Technology

Computers and internet improve data collection, analysis, and dissemination. Integration of behavioral, neural, rehabilitation, sports, and ergonomics research. Focus on practice scheduling, feedback, and motor skill learning.

Key Figures

Bernstein: Degrees of freedom, coordination. Fleishman: Motor abilities taxonomy. Fitts: Fitts' law, ergonomics. Henry: Memory drum, specificity. Adams: Closed-Loop Theory. Keele: Motor programs, attention, vision. Whiting: Catching research, journal founding. Thelen: Motor development, emergent behaviors.

Motor Program-Based Theory

Stored motor programs (GMPs), invariant features (order, relative time), parameters (speed, muscles). Solves degrees of freedom problem.

Open-Loop

Pre-planned movements, no feedback (throwing a dart).

Closed-Loop

Uses feedback to adjust (driving a car).

Dynamical Systems

Movement emerges from body-environment interaction; self-organization; attractor states; order and control parameters; coordination patterns emerge spontaneously; perception-action coupling.

Motor programs

Separate programs for walking/running.

Mechanical methodology

Observe movement patterns and success, study behavior and space.

Electrical methodology

EMG (muscle), EEG (brain).

Metabolic methodology

MRI, fMRI, PET (slow, high spatial resolution). Often combined; need to account for electromechanical delays.

Unperturbed paradigms

Observe natural movement or instructed variations.

Perturbed paradigms

Alter system (lesions, injuries, animal models) to study recovery and causality.

Kinematics

Describes movement details, causes.

Kinematics variables

Displacement, velocity, acceleration.

3D reference

Front-back, side-side, up-down.

Body segmentation

12 segments × 15 variables = 180 measurements.

Potentiometer

Measures joint rotation via current.

Strain gauge

Measures force.

Goniometer

Measures joint angles (cheap, simple; affected by skin movement).

Accelerometers

Measures limb acceleration (placement-sensitive, expensive).

Optoelectric

Markers tracked by cameras (high accuracy, full-body; occlusion/manual correction).

Electromagnetic

Sensitive to metal.

Kinetics

Study of forces causing movement.

Force platforms

Measure vertical, anterior-posterior, medial-lateral forces.

Link-segment models

Estimate internal forces from mass, kinematics.

Time on Target (TOT)

Duration aligned with target.

CE (constant error)

Average signed deviation, indicates bias.

VE (variable error)

Standard deviation, indicates inconsistency.

AE (absolute error)

Average unsigned error, overall accuracy.

Total variability (E)

Combines bias + variability.

Types of motor skills

Discrete: brief, clear start/end (button press, kick); Continuous: ongoing (swimming, running); Serial: sequence of discrete movements (typing, gymnastics).

Closed skills

Stable environment → focus on precision.

Open skills

Dynamic environment → focus on adaptability.

Reliability

Consistency across trials (fatigue, attention, instruments affect).

Validity

Accurately reflects performance (construct and face validity).

Control strategies

Standardized instructions, controlled environment, individual testing.

Lab control

Improves precision but may reduce real-world applicability.

Skill classification

Differentiates control and learning processes.