The Brain and Behaviour

1
The Brain and Behaviour

• Unit 3 Psychology

2
(No Transcript)
3
Cerebral Hemispheres

• The cerebral hemispheres are divided right down
  the middle into a right hemisphere and a left
  hemisphere.
• Each hemisphere appears to be specialised for
  some behaviours and this is called
  LATERALISATION.
• The hemispheres communicate with each other
  through a thick band of 200-250 million nerve
  fibres - the corpus callosum.

4
And

• Even though there are 2 hemispheres, they work
  together as ONE BRAIN to achieve tasks, thought,
  action and so on.
• The brain is PLASTIC and after damage, it can
  sometimes re-assign areas of the brain to take
  over from damaged areas.

5
Hemispheric Specialisation

• The right side of the brain controls muscles on
  the left side of the body and the left side of
  the brain controls muscles on the right side of
  the body.
• In general, sensory information from the left
  side of the body crosses over to the right side
  of the brain and information from the right side
  of the body crosses over to the left side of the
  brain.
• Therefore, brain damage to one side of the brain
  will affect the opposite side of the body.

6
Cerebral Cortex - Corpus Callosum
7
CORPUS CALLOSUM
A mass of nerve fibres connecting the two
cerebral hemispheres, facilitating the exchange
of information and the coordination of
activities. HINT it looks like an ear shape.
8
CEREBRAL CORTEX

• Largest area of the brain, 70 of the neurons of
  the central nervous system.
• It is about 3mm thick.
• Looks like a walnut.
• Higher mental functions thinking memory.
• There are 2 cerebral hemispheres, divided into
  four areas or cortical lobes
• Frontal Parietal Temporal
  Occipital.
• Each lobe controls a different range of
  activities.

9
FRONTAL LOBE

• The frontal lobe occupies the front part of the
  brain behind the forehead.
• Speech, motor activities (movement) and higher
  intellectual functions.
• This area of the brain is most closely associated
  with "control" of voluntary responses
• It is closely linked with making decisions and
  judgements. It is where we would find ME.

10
BROCAS AREA

• Located in the left frontal lobe near the primary
  motor cortex.
• It is responsible for the production of clear and
  articulate speech (movement, grammar and
  pronunciation).
• Brocas Aphasia is a language impairment caused
  by damage to Brocas Area. Speech is slow,
  incomplete and not fluent. Some patients cannot
  speak at all. The MOTOR SKILLS of speech have
  been damaged. They can still UNDERSTAND others
  speech.

11
Frontal Lobe Damage?

• Slower thoughts and behaviour
• Find it difficult to look for a range of
  strategies to deal with problem solving
• Loss of self-awareness and self-consciousness
• Altered emotional reactions
• Loss of spontaneity
• Alteration of time perception
• Problems with active planning and reacting to
  change

12
OCCIPITAL LOBE
The occipital lobes, located near the rear of the
brain, are associated with the visual system.
This is where visual sensations are sent and
where we analyse and reconstruct patterns sensed.
In other words, where perception happens or
where we SEE This is also called the Visual
Cortex or Primary Visual Cortex. This takes up
1/3 of the brains space.
13
Occipital Lobe Damage?

• Damage to the primary visual cortex can produce
  blindness.
• Damage to the visual association cortex (this
  includes parts of the parietal temporal lobes
  as well) of the left hemisphere affects our
  ability to recognise a visual scene.
• Familiar objects may not be recognised if there
  is damage to the right hemisphere of the visual
  association cortex.

14
Temporal Lobe

• The temporal lobe receives auditory signals and
  is mainly involved in hearing, processing
  language and interpreting the meaning of words.
• This region is also called the Auditory Cortex.
• The temporal lobe also has a role in memory and
  in facial recognition. (hippocampus)
• It also helps with vision, object recognition,
  personality and how we behave socially.

15
WERNICKES AREA

• Usually located in left temporal lobe. It is
  responsible for the comprehension of language.
  This relates to speech, writing and reading.
• Wernickes Aphasia means people have difficulty
  with comprehending language and producing
  understandable speech. Inappropriate or made-up
  words can be used and sentences often dont make
  sense. A word salad describes their speech.

16
Temporal Lobe Damage?

• Hearing impairments or deafness.
• Problems with memory, object recognition, naming
  objects, personality change.
• Ability to comprehend speech and language
  diminished and their own language shows problems
  with structure and function.

17
Parietal Lobe

• The parietal lobe receives and processes sensory
  information from the body. It gives us space
  perception and lets us judge where our body IS.
• It is associated with the sensory cortex and
  processes information about touch, taste,
  pressure, pain, heat and cold.
• The parietal lobe is also sometimes called the
  Sensory Cortex as it adjoins the Primary
  Somatosensory Cortex.

18
Parietal Lobe Damage?

• A loss of the feedback system of the
  somatosensory cortex our bodily sensations
  wont be registered.
• Problems with reacting appropriately to heat,
  pain and so on. How can we register what is
  being sensed?
• Left parietal damage can result in alexia
  (inability to read) or agraphia (inability to
  write / draw).

19
PRIMARY MOTOR CORTEX

• The primary motor cortex helps coordinate all
  voluntary muscle movements. It is involved in the
  planning and control of these voluntary bodily
  movements.
• Neural messages FROM the motor cortex are
  EFFERENT and leave the brain ( E like the word
  Exit!)
• It is located in the Frontal lobe.

20
PRIMARY SOMATOSENSORY CORTEX
Receives sensory information from the receptor
cells in the skin and skeletal muscles. Neural
messages TO the somatosensory cortex are
AFFERENT It is located in the Parietal Lobe.
21
SAME

• S - sensory
• A - afferent
• M - motor
• E - efferent
• Remember the acronym!

22
Hemispheric specialisation
In individuals with normal hemispheric
dominance, the left hemisphere controls language
and general cognitive functions. Lefthanders
have a 60chance of having their speech areas in
the left hemisphere, 15 right hemisphere and 15
mixed over both hemispheres. The right hemisphere
manages nonverbal processes, such as attention,
pattern recognition, line orientation and the
detection of complex auditory tones.
23
LEFT

• Movement and sensation for RHS body
• Verbal tasks (speech, comprehension, reading,
  writing)
• Analysis (Maths, calculations, sequential tasks,
  evaluations)
• Logical reasoning (factual comparisons,
  argument)
• Ordering and coordinating complex movements
• Time and rhythm.

24
RIGHT

• Movement and sensation for LHS body
• Non-verbal tasks and processing the whole
• Spatial and visual thinking (visualising places,
  putting together a cut up picture, map reading,
  seeing patterns, recognising faces)
• Being creative idea generation
• Fantasy (daydreams, possibilities)
• Appreciation of art and music
• Recognising and expressing emotions (interpreting
  body language)

25
Hemispheric Specialisation

• There is constant communication between
  hemispheres to achieve tasks.
• There is symmetry between left and right
  hemispheres 2 occipital, 2 temporal, 2 parietal
  and 2 frontal lobes.
• However this symmetry is not exact - for example,
  the area associated with language appears only on
  the left hemisphere in most people 95 of
  people.

26
SPLIT BRAIN SPERRY

• Done to prevent epileptic seizures across the
  hemispheres. Initial research by Sperry.
• Corpus callosum severed to disconnect hemispheres
  and stop neural impulses travelling across.
  Optic nerves stay intact.
• Individuals function normally on a day-to-day
  basis.

27
Brain Research Imaging Techniques
28
CASE STUDY

• In-depth study of some behaviour or phenomenon of
  interest in a particular individual, group or
  situation. May involve a combination of
  observations of behaviour, diagnostic tests,
  interviews and analysis of medical records.

29
Advantages?

• Information obtained is very detailed and
  provides a comprehensive understanding of the
  person and their problems.
• Useful as a source of ideas and hypotheses.

30
Limitations?

• Time consuming process.
• Problems generalising to other individuals.
• Brain injuries rarely localised or limited to one
  particular area.
• The brain is plastic and able to adapt and
  re-assign function to another area of the brain,
  so true effects of damage are difficult to
  guarantee.

31
Electrical Stimulation of the Brain

• Electrodes can be used to stimulate parts of the
  brain so that brain function can be observed,
  therefore used for surgery e.g. Location of
  speech areas.
• Electrical stimulation of selected areas of the
  brain can provide a 3 dimensional brain-map to
  demonstrate deliberately induced responses. This
  is called Electrical Stimulation of the Brain -
  ESB.
• This is INVASIVE and carries risks. Penfield did
  this to map the brain.

32
Penfield ESB image
33
WADA Test

• Half the brain is anaesthetised or put to sleep
  via an injection into an artery.
• Functions or behaviours still occurring are
  happening in the hemisphere of the brain that is
  awake.
• Allows us to see lateralisation of the brain and
  check for the placement of vital functions such
  as speech and memory.
• WEIRD FACT a person may be unable to speak or
  comprehend language but can still SING!

34
ELECTROENCEPHALOGRAPHYPhew, long word to learn
to spell

• This measures the waves of electrical activity
  produced by the brain.
• Small disc-shaped metal plates are put on a
  persons scalp. These discs detect electrical
  impulses from the brain and send them to an
  electroencephalograph which amplifies these brain
  waves and records them via computer on a sheet of
  paper.
• The patterns are then examined for changes or
  unusual patterns that may indicate injury or
  illness.

35

36
Advantages?

• Procedure is harmless and less invasive than ESB.
  
• Equipment is easily accessed.
• It can be used to study brain activity over a
  long period of time.
• It has provided information about brain activity
  associated with thoughts, feelings and behaviour.

37
Limitations?

• It is unable to provide information about
  specific brain structures and what their function
  is.
• Unable to be specific about the exact location or
  the ORIGIN of the waves produced by the brain
  often quite general.
• Time consuming to complete.

38
COMPUTERISED AXIAL TOMOGRAPHY CAT or CT

• X-Ray information of the brain is collected by a
  computer and compiled into an image of the brain.
  This is a useful tool in detecting abnormalities
  in brain tissue.However the CT does not provide
  information about how the brain actually
  functions. It is STRUCTURAL information

39
Advantages?

• Non-invasive.
• Can be used for healthy and abnormal brains
• Slices can combine for a 3D image
• Identifies the precise location and extent of
  structural damage or abnormalities in the brain.
  e.g. tumours or damage from a stroke

40
Limitations?

• It only shows brain structure and does not
  provide any information about the functioning of
  the brain.
• X-rays should be limited for health reasons, as
  they are radioactive. Thought to be negligible
  levels of radiation for CAT scans.
• Only gives slices THROUGH brain, so horizontal
  images only.

41
MAGNETIC RESONANCE IMAGING - MRI SCANA very
strong magnetic field produces an image of the
brain. A person is put inside a machine that
collects the magnetic information from atoms
moving or resonating in the brain, which a
computer then generates into a 3 dimensional
representation of the brain. Researchers can then
see into the living brain. More detailed than
CT/CAT
42
Advantages?

• More sensitive than CT/CAT scan and produces more
  detailed images.
• It does not use X-rays or radioactive substances.
  
• Can detect and display extremely small changes in
  the brain
• Can be imaged from different angles, not just
  horizontal like CT/CAT.

43
Limitations?

• Cant be used with metal implants (pacemakers,
  metal plates) because of the huge magnetic force.
• Not useful for claustrophobics or uncooperative
  (moving) individuals.
• It only shows STRUCTURE of the brain, not
  function.

44
POSITRON EMISSION TOMOGRAPHY - PET Scan

• Injected with a harmless radioactive glucose
  which travels to the brain.
• Provides images of the working brain by tracking
  blood flow around the brain as it uses the
  glucose.
• Computer detects radioactive signals and
  generates colour-coded pictures of brain
  activity.
• It gives information about brain function as a
  person completes a required task.

45
Advantages?

• It provides information about brain function and
  activity during various tasks.
• Can be used for healthy or damaged brains.
• Enables detailed images of the functioning brain.
  
• It is possible to observe how different areas
  interact when a person is doing a particular
  task.
• People with intact brains can be actively used in
  research.

46
Limitations?

• Less detailed than MRI scans no real
  identification of structures doing the work.
• Requires in injection of radioactive glucose,
  however it is meant to be harmless in quantity.
  Therefore, there is a limit to the number of PET
  Scans that can be taken in an individual, so
  rapid changes in brain activity may not be picked
  up.
• Level of brain activity observed in different
  areas may be related to factors other than the
  specific task itself eg. The duration or
  difficulty of the task.

47
(No Transcript)
48
fMRI

• Functional Magnetic Resonance Imaging uses a
  magnetic field like MRI.
• Allows REAL TIME imaging of a brain (3-5 secs).
• Measures the oxygenated blood flow and oxygen use
  of the brain, as the brain uses it. The brain
  uses more glucose and oxygen than any other
  organ.

49
Advantages?

• Non-invasive and safe no surgery or injections.
  
• It can take numerous pictures of the brain in
  quick succession and images are more detailed and
  precise compared to PET Scans (and cheaper).
• Suitable for a range of patients and issues.
• Gives structure AND function and is the only
  one that does this.

50
Limitations?

• May be compromised by the 2 Ds
• Duration of task boredom?
• Difficulty of task too hard, confused?
• Not subject friendly loud and claustrophobic
  environment.
• No magnetic METAL the same as MRI
• Hard to compare data because of variation of
  blood flow with individuals.

51
Functional Connectivity During Reading
Comprehension

• fMRI imaging
• Brain areas interact to
• work as a whole

52
IMAGING TechniquesStructure or Function?

• STRUCTURE
• CT or CAT Scan
• MRI
• fMRI

• FUNCTION
• EEG
• PET
• fMRI

53
The Autonomic Nervous System

• A system of nerves that carry information to and
  from internal organs and glands.
• Is automatic and involuntary we dont control
  it breathing, heart rate, perspiration.
• Goal is to maintain the body at optimum state of
  functioning and in a balanced state homeostasis.

54
ANS divisions?

• Sympathetic Nervous System
• Responds by releasing adrenaline to increase the
  activity or arousal of the body more energy.
• Threats activation
• Exercise activation

• Parasympathetic Nervous System
• Responds by calming or counterbalancing the body
  BACK to a resting state by decreasing the bodys
  responsiveness and restoring homeostasis

55
How do they interact?

• SNS activates and
• Inhibits digestion, salivation, tears,
  elimination of waste, bladder control.
• Increases pupil dilation, heart rate, blood
  pressure, perspiration, respiration and releases
  sugars from liver and adrenaline from the adrenal
  glands.

• PNS works to...
• Return the functioning of these body organs and
  systems to a level of homeostasis or a balanced
  state of equilibrium to conserve energy.
• The PNS is working constantly.

56
Fight or Flight

• A state of arousal that prepares or mobilises the
  body to deal with a perceived threat to survival
  or safety.
• The body is aroused to confront the threat
  stand and FIGHT
• OR
• Run away or flee from the threat take FLIGHT.
• The Sympathetic NS takes over and prepares us for
  ACTION.

57
The Polygraph

• A device to measure autonomic functions to
  indicate level of physiological arousal.
• Use as a Lie Detector is based on the theory
  that when we tell lies, our physiological arousal
  changes.
• It tracks respiration (rate of breathing), heart
  rate (pulse), blood pressure and galvanic skin
  response (electrical conductivity of skin).
• Theory when we lie, these all INCREASE. A
  baseline is established first to record normal
  physiological responses.

58
Questions asked?

• CONTROL or BASELINE questions
• Unrelated to the investigation.
• Should NOT, in theory, elicit a heightened
  physiological arousal.
• Used to COMPARE against relevant questions.

• RELEVANT or CRITICAL questions
• Relate directly to the investigation being
  studied.
• Should, in theory, show a heightened
  physiological arousal.
• Used to indicate lies.

59
Limitations?

• Guilt and anxiety produce similar arousal.
• Being accused of something and being asked
  questions about it may produce high levels of
  arousal, even though innocent.
• Hardened criminals may not experience stress or
  guilt. Sociopaths may not experience or
  understand guilt, or right VS wrong.
• It is possible to self-harm in order to produce a
  pain response, which is similar in physiological
  arousal to guilt.

60
Intense and prolonged arousal

• Stress is the bodys response to threatening or
  challenging events.
• Whether we experience stress depends on our
  perception of events.
• A stressor is the event or circumstance that has
  the potential to produce stress. We must respond
  to the stressor.
• They can be both physical (in the environment) or
  psychological (mental).

61
What are the consequences of stress?

• Prolonged or intense stress weakens the bodys
  immune system.
• Cortisol produced to fix organs and systems,
  starts to create damage.
• This makes the body more vulnerable to attack
  from bacteria and viruses.
• Stress reactions can be
• Physical/physiological muscle tension,
• Emotional/psychological depression, anger
• Cognitive low concentration and problem
  solving
• Behavioural agitation or aggression

62
Stress and Disease

• Prolonged or intense stress has been linked to
  disease.
• Asthma, high blood pressure, migraines,
  constipation, diarrhoea, ulcers, arthritis, heart
  disease, indigestion, insomnia, PMT, eczema,
  sexual problems

• These are PSYCHOSOMATIC disorders - illnesses in
  which psychological factors play a part in
  producing physical damage to the body or how the
  body functions.
• They relate to over-arousal of the ANS

63
Selyes GAS (1956)

• General Adaptation Syndrome or GAS
• Selyes stages can make the acronym of SCARE
• S - shock and C - countershock create the..
• A - alarm stage
• R - resistance
• E - exhaustion

64
(No Transcript)
65
GAS Stages

• SHOCK
• 1st stage of ALARM
• We are faced with a new stressor
• Body temporarily goes into shock.
• Our resistance to stress drops below normal
  levels.
• Blood pressure, body temperature DROP and loss of
  muscle tone.

• COUNTERSHOCK
• 2nd stage of ALARM
• Bodily resources mobilised to fight or deal with
  stressor.
• Enter state of high arousal and alertness (SNS
  kicks in adrenaline).
• Similar to Fight or Flight.

66
Gas Stages

• RESISTANCE
• Stressor not dealt with effectively??
• Attempt to cope or adjust to stressor and normal
  level of coping rises.
• Physiological symptoms disappear temporarily.
• Physical cost susceptible to other stressors,
  lowered immunity to disease, psychosomatic
  disorders may appear.

• EXHAUSTION
• Stressor not dealt with effectively??
• Unable to overcome the threat, energy resources
  are depleted.
• High level of physical wear and tear on organs.
• Extreme fatigue, anxiety, feelings of
  hopelessness, depression, disturbed sleep,
  ulcers, blood pressure, possible collapse.

67
Do we all react the same way?

• Some individuals experience wildly different
  reactions to stressors. Do you like exams,
  rollercoasters or throwing yourself out of a
  perfectly good plane? Some people do!
• Most stressors are dealt with in the Alarm
  Reaction stage.
• Some specific stressors appear to produce unique
  reactions even at a hormonal level.

68
Coping with STRESS

• Exercise 15 mins
• Relaxation
• Social support
• Talk with someone
• Ask for help
• Get organised
• Plan for success
• Find humour
• Try to balance life commitments

• Learn to meditate etc
• Set priorities lists
• Have varied interests
• Positive mental set
• Take time out
• Know what you CAN do
• ROYGBIV
• Stop being your own worst critic