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

BRAIN FUNCTIONS AND THE SENSES

Planning Movement 96 97

Deciding how to move

The dorsolateral frontal cortex

and parietal cortex work together to

plan the movement. This information

is sent via the basal ganglia (see pp.32–33)

to the PMA and SMA, which specify the

sequence of muscle contractions needed.

2

Getting ready for action

Signals travel to the primary

motor area, which forwards instructions

to the cerebellum and brain stem to be

fine-tuned. Signals from these areas return

to the primary motor area, which sends the

signal for action to the spinal cord.

3

DORSOLATERAL

FRONTAL CORTEX

POSTERIOR

PARIETAL

CORTEX

CEREBELLUM

SMA

Command for action

sent via spinal

cord to muscles

PUTAMEN

THALAMUS

GLOBUS

PALLIDUS

Dorsolateral

frontal cortex

sends signals to

basal ganglia

Putamen receives

signals from frontal

and parietal areas

KEY

Signals to

cerebellum

Signals from

cerebellum

Regulating movement

The basal ganglia are a group of nuclei that

are linked to the thalamus. Signals from frontal

and parietal areas are processed by circuits in

the basal ganglia that amplify or inhibit

movement signals.

Thalamus relays signals

from basal ganglia to

PMA and SMA

Information exchanged

between cerebellum

and brain stem

Posterior parietal cortex

signals conscious intention to

move via basal ganglia

Making adjustments

Signals from the primary motor area are

sent to the cerebellum, which plays a role

in measuring time. It also makes real-time

adjustments to movements in response to

our environment.

SPINAL CORD SPINAL CORD

Dentate nucleus

makes subtle

adjustments to

motor plans

Primary motor area has

command-feedback links with

cerebellum and basal ganglia

Globus pallidus

inhibits unwanted

movements

Subthalamic

nucleus involved

in impulse control

Substantia

nigra controls

strength of

actions

Once signals have

been regulated, thalamus

forwards to PMA and SMA

Cerebellar

cortex

coordinates

timing

PMA

DENTATE

NUCLEUS

Basal ganglia

strengthen or

weaken signals

F

R

O

N

T

C

R

O

S

S^

SE

CT

IO

N

THALAMUS

PUTAMEN

BASAL

GANGLIA

PRIMARY

MOTOR AREA

BASAL

GANGLIA

CER

EB

EL

LA

R

CO

RT

EX

S

ID

E

C

R

O

SS

S

EC

TI

ON

Brain stem passes

information back to

primary motor

area once it is

fine-tuned

BRAIN STEM

BRAIN STEM

US_096-097_Planning_movement.indd 97 20/09/2019 12:35