How the Brain Works The Facts Visually Explained by DK (z-lib.org)

BRAIN FUNCTIONS AND THE SENSES

Unconscious Movement 100 101

Planning

The brain combines real-time

visual information and stored programs

for movement sequences to create a

plan of action. This is first rehearsed in

the premotor area and then sent to the

primary motor cortex.

Conscious action

By the time the player becomes

conscious of acting, the movement

sequence is well underway. The action

is most likely to be effective if the

person has sufficient skill, stored

knowledge, and information.

3 4

Reflex actions

Reflexes are split-second responses

to danger that we do not have to learn

or even think about; the body reacts

automatically. Reflex actions involve the

same muscles that are used in voluntary

movements, but the initial, instantaneous

response does not involve the brain.

Instead, the signal from the sensory

nerves travels to the spinal cord, which

triggers a response that travels along the

motor nerves. Additional signals are sent

to the brain afterward, to encode the

memory in case the danger recurs.

Bypassing the brain

Reflexes involve a simple neural

response called the reflex arc.

Receptors in the skin and muscles

send a danger signal along sensory

neurons to the spinal cord; there, relay

neurons synapse with motor neurons

to trigger a fast response.

OUR NEURONS AND

NERVE PATHWAYS CHANGE

CONSTANTLY IN RESPONSE

TO EXPERIENCES

Anyone learning a new skill passes

through several stages. Beginners have

to work hard to acquire competence.

With practice, neural pathways

develop until the learner can perform

well without thinking about it.

DEVELOPING COMPETENCE

Additional relay

neurons send

signal to brain

Movement

sequence

begins

Motor neuron

sends signal

to muscle

to contract

MUSCLE

STIMULUS

SPINAL CORD

Ball coming

toward player

Sensory neurons

send signal to

spinal cord

Receptors in

skin detect heat

from flame

Relay neurons

in spinal cord

generate response

Premotor

area plans

movement

1

2

3

4

5

MOTOR

CORTEX

VISUAL

CORTEX

Primary motor area plans

and executes movement

KEY

Signals to spinal cord

Signals to muscle

Signals to brain

Conscious

competence

Able to use skill,

but only with effort

Unconscious

incompetence

Unaware of skill needed

and lack of proficiency

Conscious

incompetence

Aware of skill needed

but lacking proficiency

Unconscious

competence

Performing skill

is automatic

US_100-101_Unconcious_Movement.indd 101 20/09/2019 12:35