1. Four Lobes of the Cerebral Cortex

Structure and function: different parts of the brain
control different functions.
The frontal Lobe
The frontal Lobe
 Primary motor cortex – movement
 Broca’s area speech production
 Forward area association judging planning initiative
 Expression of characteristics associated with
personality and emotional behaviour
 (The motor is in the front of the car Broca’ is driving)
The frontal Lobe as a car?
Phineas gage – frontal lobe damage
 September 13, 1848, 25-year-old Railway foreman
 Packing gun powder into a hole with a steel pole to
blow up rock
 Sparks from the pole ignite the gun powder and send
the pole under gage’s cheek and out the top of his head
 Before the accident he was well liked, organised, calm
and polite
Phineas gage – frontal lobe damage
After the accident Phineas suffered severe personality changes
Became impulsive, aggressive, disorganised
Could not continue his work as foreman
Appeared for a time at Barnum's American Museum in New York
February 1860, Gage had the first in a series of increasingly
severe convulsions
 died in or near San Francisco on May 21 — just under twelve
years after his accident
 Gage’s case along with others suggest the frontal lobes important
role in emotion and personality, planning and initiative
The Parietal lobe
The Parietal lobe
 Primary Somatosensory cortex
 Receives info from senses
 Somatosensory cortex at front of temporal lobe next to
primary motor cortex which is at the back of the
frontal lobe
 (The party lobe, your senses are going wild at a party)
The Parietal lobe – on fire at a party?
Motor and Sensory Cortex organisation
The homunculus man
The temporal Lobe
The temporal Lobe
 Primary auditory area
 Wernicke’s area speech comprehension
 Primarily associated with hearing
 Also important role in memory
 Decisions made about which features of environment
we will remember
 Facial recognition also performed in temporal lobe
 (Temporal sounds like tempo, the tempo of the music)
The Primary Auditory Cortex
 Resides in each temporal lobe
 Receives and processes sounds from both ears
 Each primary auditory cortex has specialised areas of
sound and thus play vital roles in the identification of
 Two main features of sound: frequency (perceived as
pitch) and amplitude or intensity (perceived as
 Each primary auditory cortex is also specialised to process
different types of sound. Verbal sounds (e.g. words) in the
left hemisphere and non-verbal sounds (e.g. Music)
processed in the right hemisphere. BUT there is some
overlap, this is not exclusive!
Temporal Lobe Association Areas
 Located in each temporal lobe
 Different association areas appear to be involved in memory
(including linking emotions with memory and determining
appropriate emotional responses to sensory info and memories)
 Amnesia (partial or complete loss of memory) often occurs in
people with damage to either or both temporal lobes.
 Receiving, processing and storing of facts (semantic memories)
how to do things (procedural memories) and personal
experiences such as birthdays or holidays (episodic memories)
appear to occur in areas of the temporal lobes.
 Object identification and facial recognition are also involved,
thus perception and memory to make decisions about our
environmental features is an important role of the temporal
lobe.. However, perception and memory are not exclusive to one
area of the brain but involve many interconnected areas.
 Located towards the rear of the temporal lobe
 In left hemisphere only (next to primary auditory cortex)
and connected to Broca’s area by a bundle of nerves.
 Has crucial role in comprehension of speech, but is also
involved in speech production, more specifically,
interpreting the sounds of human speech.
 Word is heard, then the auditory sensation is processed by
the primary auditory cortex of the left temporal lobe, but
the word cannot be understood until the information has
been processed by Wernicke’s area.
 Also vital for not just understanding words, but also for locating
appropriate words from memory to express intended meanings
when we speak or write.
 When a word is to be spoken, a “representation” of it is
transmitted to Broca’s area in the frontal lobe which co-ordinates
the muscles needed to produce the sound of the word and
supplies this information to the face area located where the
temporal and occipital lobes intersect.
 Damage to Wernicke’s area causes impairment in understanding
speech and to speaking.
 Read Box 4.5 on page 194
The temporal Lobe as a drummer?
Deep within the temporal lobe- the
Deep within the Temporal lobe –
the hippocampus
 Memory formation – not memory storage
 Damage leaves patient unable to form new long term
 The hippocampus lives on memory lane
Deep within the temporal lobe- the
 Mediation of fear
 Seizures involving the amygdala involve intense fear
 Damage leaves a person unable to learn a fear response
through classical conditioning
 Involved in remembering the emotional significance of an
 Damage leaves us unable to judge emotional component of
facial expressions in others – i.e. angry person perceived as
calm or even happy
The Occipital Lobe
The Occipital Lobe
 Primary visual area
 Visual cortex located at base of each occipital lobe – is
the major destination of visual inforamtion from the
two eyes.
 Other areas visual association areas – identifying
objects etc.
 (Occipital sounds like optical, optical relates to vision)
 Located at rearmost area of each cerebral hemisphere
 Almost exclusively devoted to the sense of vision
 Damage can produce blindness even if eyes and neural
connections to brain are normal
 Some areas in other 3 lobes also have important visual
 Divided into many different visual areas - the largest
being the primary visual cortex (at the base of the
occipital lobe).
 Information arrives at PVC via visual sensory receptors
(“photoreceptors”) on the retina at the back of each eye.
 Each hemisphere receives and processes half of visual
information. Left half of each eye receives visual sensory
information from right half of visual field and sends info to
left occipital lobe and vice versa. See Box 4.12 on page 224
 Neurons in the PVC and surrounding “secondary” visual
areas specialise in responding to different visual features
e.g. Orientation (direction) of a line, edges, shapes
(forms), motion and colour. Some neurons respond to one
feature only, others to two or more features.
 Have important roles in vision.
 They interact with PVC to select, organise and integrate
visual information.
 They interact with association areas of other lobes to
integrate visual information with other information (e.g.
Memory, language, sounds), so that visual information can
be organised and interpreted in a meaningful way.
 E.g. The frontal lobe (together with parietal lobe) is involved
in spatial reasoning such as trying to work out whether a
specific piece of a jigsaw puzzle will fit into a particular place
in the puzzle.
The Occipital Lobe as an eye?
 Areas other than the visual cortex are also involved in
processing visual information to enable visual
 Research evidence suggests there are 2 major pathways
from the visual cortex in the occipital lobe to areas of
the temporal and parietal lobes – they are the dorsal
stream and the ventral stream.
Dorsal and ventral streams
 Dorsal (“upper”) stream includes areas of the occipital
lobe and leads to parietal lobe.
 Specialises in locating objects or spatial perception (where an
object is and relating it to other objects in a scene). – the
“where” pathway
 Ventral (“lower”) stream includes areas of the occipital
lobe and leads to the temporal lobe.
 Specialises in object perception and recognition (identifying
objects) – the “what” pathway
See Figure 4.29 on page 197
 Case studies of patients with brain damage to specific areas
of the visual cortex provide evidence in support of the
differing roles of the ventral and dorsal streams.
 Patient D.F. suffered carbon monoxide poisoning at 34
years of age which damaged brain areas involved in the
“what” pathway.
 D.F. could no longer recognise the faces of her friends and
family, common objects or even a drawing of a square or
circle. Her condition was diagnosed as “object agnosia”
(the inability to recognise objects).
 D.F. could recognise people by their voices and could usually say
what objects placed in her hands were, through memory of
voices and past experiences with objects using touch and other
 When presented with a drawing of an apple, D.F. cannot identify
or redraw it. But if asked to draw an apple, she can do it from
 D.F. can use visual information about the size, shape and
orientation of objects to control visually guided movements,
suggesting her “where” pathway has not been damaged. E.g. she
can walk across a room and step around things without difficulty
and can also reach out and shake hands as easily as we all do.
 D.F. can reach out and grasp a block, with the exact
correct distance between her fingers, but she cannot
tell you what she is going to pick up or how big it is.
 Her conscious perception of objects is impaired, she
has no awareness of taking in any visual information
about objects she sees.

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