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

BRAIN FUNCTIONS AND THE SENSES

Planning Movement

Planning Movement

Conscious movements are those that we deliberately decide

to make. They involve several regions of our brain and include

processes that lie outside our conscious awareness.

The planning process

There are several stages involved in carrying out a movement—from

initial perception of the environment, to planning, to adjustments

during the movement. These stages involve different areas of the

brain working together to produce a response. The area that prompts

the movement is the motor cortex. Different sections of the motor

cortex send signals to different parts of the body (see p.98). However,

before an action begins, an action plan is created by the dorsolateral

frontal cortex and the posterior parietal cortex and is passed through

two areas of the motor cortex: the supplementary motor area (SMA)

and the premotor area (PMA). The cerebellum coordinates the

movement as it is happening. The steps above show the brain areas

involved and the sequence of signals in a typical movement.

Putamen feeds stored

information to posterior

parietal cortex

Gathering information

Sensory areas, such as the visual

cortex, send signals to the frontal cortex.

The putamen, which stores learned actions,

sends information to the parietal cortex,

which assesses whether these learned

actions could be used in this new situation.

1

When we prepare for a voluntary action, a buildup of

electrical activity, called the readiness potential, occurs.

It begins in the SMA and is intensified by activity in the

PMA. Activity in the SMA starts up to 2 seconds before

we become consciously aware of our decision to move—

which may suggest that we are less in control of our

actions than we might believe (see p.168).

READINESS POTENTIAL

THALAMUS

DORSOLATERAL

FRONTAL CORTEX

POSTERIOR

PARIETAL

CORTEX

VISUAL

CORTEX

Time (seconds)

–3 –2 –1 0 1

Activity in

SMA

0

Activity

Activity in

PMA

WHY DON’T WE

FORGET HOW TO RIDE

A BICYCLE?

Nerve cells in the putamen

encode the sequence of muscle

movements into our long-term

memory storage so that

they are easily accessible

even years later.

Sensory information is sent

from visual cortex via thalamus

to dorsolateral frontal cortex

SPINAL CORD

THE CEREBELLUM CONTAIN S

MORE THAN 50 PERCENT

OF THE BRAIN’S NEURONS

Posterior parietal cortex receives

information from putamen and also

assesses body’s position in relation

to surroundings

BASAL

GANGLIA

Time of actual

movement

PUTAMEN

US_096-097_Planning_movement.indd 96 20/09/2019 12:35