Breakdown of Marks
Psychology Study Score
Unit 3 Exam
33%
Unit 4 Exam
33%
SAC work
(Unit 3 &Unit 4)
34%
Exam Revision for Brain and
Nervous System – Area of
Study 1
The Brain
• Cerebral Cortex
– Comprises two hemispheres (left & right)
of nerve tissue
– Hemispheres are joined by a band of nerves
called the corpus callosum which allows the
hemispheres to communicate
– Each hemisphere has four lobes: frontal,
parietal, occipital, temporal
– Each hemisphere's surface is covered by a
thin (3-5mm), convoluted (folded) layer of
neurons called the cerebral cortex
– Generally involved with information
processing (e.g. perception, memory,
thinking, language)
– Neurons in the cerebral cortex process
sensory and motor information
Frontal Lobe
• Enables higher mental functioning involving
learning and memory and control over complex
movements, including the mechanics of speech
(Broca’s area).
• This region also controls emotions, personality
and intellectual tasks requiring reasoning and
planning.
Primary Motor Cortex
– Controls voluntary movements of skeletal
muscles
– Motor cortex in left frontal lobe controls
voluntary movements on right side of body
and vice versa
– Areas at top of motor cortex control lower
parts of the body and vice versa
– Amount of motor cortex is related to
precision of movement of area (e.g. hands
fingers, mouth, lips, have proportionately
more motor cortex)
• Broca’s Area
– In left
hemisphere
only and
involved in
production
of speech
Parietal Lobe
• Mediates attention and is involved in
spatial perception and bodily awareness
based on sensations of touch pressure,
pain and body movement.
Primary Somatosensory Cortex
• Receives and processes sensory inputs
from the body (i.e. body senses)
– Sensory cortex in left parietal lobe
processes sensory information from the
right side of body and vice versa.
– Amount of sensory cortex is related to
sensory sensitivity of body area (e.g.
mouth, lips, tongue and genital areas have
proportionately more sensory cortex)
Occipital Lobe
• The primary visual cortex enabling
perception
Primary Visual Cortex
• Receives and processes visual signals
from two eyes
– Right occipital lobe processes left visual
field information (inputs from the right
half of each eye)
– Left occipital lobe processes right visual
field information (inputs from the left half
of each eye)
Temporal Lobe
• The main location where auditory
information is projected, enabling hearing
to register.
• This region left hemisphere of the brain
contains Wernicke’s area, a language
centre where speaking reading, writing and
spelling are processed.
• Also, this location acts as a centre for the
recognition of different visual forms,
enabling individuals to distinguish one
object from another (role in memory)
Primary Auditory Cortex
• Receives and processes auditory information from the
ears
– Left temporal lobe processes verbal sounds (e.g. words)
– Right temporal lobe processes non- verbal (e.g. music)
Wernicke’s Area
• In left
hemisphere
only involved in
comprehension
of speech
Broca’s & Wernicke’s Area
Area
Location
Function
When Damaged
Broca’s Area
Left frontal lobe
(next to motor
cortex)
Controls facial
muscles and larynx
to produce speech
(i.e. stores
articulation codes
for clear and fluent
speech)
Causes expressive
aphasia – an
inability to produce
fluent speech
without disruption
to comprehension
of spoken or
written language
Wernicke’s
Left temporal lobe
(next to auditory
codes for language)
Controls
comprehension of
speech and
language (i.e.
stores auditory
codes for language)
Causes receptive
aphasia – an
inability to
comprehend
meanings of spoken
words or language
without disruption
to speech
production
however, the
person’s speech is
meaningless
Hemispheric Specialisation
Left Hemisphere
Right Hemisphere
Verbal Tasks: production and
comprehension of speech and language,
reading and writing
Non verbal and visual-spatial tasks: object
and pattern recognition, map reading,
musical melodies, painting, poetry
Rationality (i.e. logical reasoning)
Emotional expression and recognition
Processes information logically,
sequentially, analytically (e.g.
mathematics, science)
Processes information holistically (i.e.
whole patterns simultaneously) and
intuitively (i.e. less logically)
Processes sensory information from
body’s right side
Processes sensory information from
body’s left side
Controls voluntary movements and
sensations of body’s right side
Controls voluntary movements and
sensations of body’s left side
Hemispheric Specialisation
• The tendency for
one hemisphere
to be dominant
(i.e. more
specialised, exert
greater control)
in certain
cognitive and
behavioural
functions.
Hemispheric Specialisation
Research on People with intact Brains
• Psychological studies
– Of people with intact (undamaged) brains
indicate specialisation of left hemisphere
for verbal tasks and specialisation of right
hemisphere for non verbal tasks; however
there is some overlap in functions between
hemispheres.
Evidence for Specialisation includes
Results of neuro-imaging studies
• EEG studies
 Brainwaves activity greater in left hemisphere
with verbal tasks; greater in right hemisphere
with spatial tasks
• Tachistoscope Studies
 Left hemisphere identifies verbal stimuli (words)
more quickly when briefly flashed to right visual
field and right hemisphere identifies non-verbal,
spatial stimuli (e.g. pictures of objects) more
quickly when flashed to the left visual field
Research On people with
Split Brains
• Split Brain Studies
– Ability to verbally name and identify words and
objects flashed to the right visual field (i.e.
sent to left hemisphere); but
– Inability to verbalise words or name objects
flashed to the right visual field (i.e. sent to
left hemisphere); but
– Inability to verbalise words or name objects
flashed to left visual field (i.e. sent to the
right hemisphere); patients can identify these
objects by touch alone using their left hand
(i.e. controlled by the right hemisphere)
– Severed corpus callosum prevents hemispheric
exchange of information.
So, say a "typical" (language in the LEFT hemisphere)
split-brain patient is sitting down, looking straight
ahead and is focusing on a dot in the middle of a
screen. Then a picture of a spoon is flashed to the
right of the dot. The visual information about the
spoon crosses in the optic chiasm and ends up in the
LEFT HEMISPHERE. When the person is asked what the
picture was, the person has no problem identifying the
spoon and says "Spoon." However, if the spoon had
been flashed to the left of the dot (see the picture),
then the visual information would have travelled to
the RIGHT HEMISPHERE. Now if the person is asked
what the picture was, the person will say that nothing
was seen!! But, when this same person is asked to pick
out an object using only the LEFT hand, this person
will correctly pick out the spoon. This is because touch
information from the left hand crosses over to the
right hemisphere - the side that "saw" the spoon.
However, if the person is again asked what the object
is, even when it is in the person's hand, the person will
NOT be able to say what it is because the right
hemisphere cannot "talk." So, the right hemisphere is
not stupid, it just has little ability for language - it is
"non-verbal."
• Wada test
 When a hemisphere is anaesthetised, limbs
on opposite side of body go limp; when the
left hemisphere is anaesthetised, language
is impaired.
Central Nervous System
• The central nervous system (CNS) the
section of the nervous system that
includes the brain and the spinal cord.
• The spinal cord forms part of the
central nervous system, and connects
the brain to other areas of the body.
The Peripheral Nervous System
(PNS)
• The peripheral nervous system links the
central nervous system to other parts
of the body and is divided into the
somatic nervous system and the
autonomic nervous system.
Somatic nervous system
in the control of skeletal muscles
• The somatic nervous system transports messages to
and from the sense organs and the spinal cord.
• The somatic system, via its connections with the
skeletal muscles, controls voluntary actions like
waving one’s hand or other bodily movements.
• Nerves from the somatic system do not control any
of the non-skeletal muscles, such as the heart, lungs,
stomach, intestines, etc.
Autonomic nervous system (ANS)
in the control of the non skeletal muscles
• The autonomic nervous system controls involuntary
bodily activities, such as digestion and heart rate,
when nerves transmit information to and from the
glands and internal organs enabling a balanced state.
Autonomic = Automatic
The Autonomic Nervous System involves automatic
(involuntary) processes.
Distinction between sensory and motor
neuron activity within the somatic nervous
system
• Sensory (afferent) nerve fibres receive sensory
stimuli arising inside or outside the body and transmit
them inwards to the central nervous system where
they are correlated.
• The motor (efferent) nerve fibres transmit
information outwards, away from the central nervous
system, enabling the co-ordination of organs such as
muscles and glands.
• This allows them to work harmoniously ensuring the
well being of the individual
Nervous System
Sympathetic
Increases responsiveness of muscles and
organs during activity, stress or when
threatened (e.g. fight or flight)
Parasympathetic
Decreases responsiveness of muscles and
organs, thereby restoring the body’s
functioning (e.g. relaxation response)
Function
Sympathetic
Parasympathetic
Arousal, Responsiveness
Increases
Decreases
Expenditure of Energy
Increases
Decreases
Heart Rate, Blood
Pressure, Respiration
Increases
Decreases
Adrenal Gland
Secretions
Increases
Decreases
Digestion
Slows
Increases
Blood Sugar level
Increases
Decreases
• Imagining a parachute floating down to
the ground may help you to remember
the prefix for the Parasympathetic
branch which brings physical
mechanisms back down to normal levels
again, relaxing the body after arousal.