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SEMESTER TWO: CLINICAL ASPECTS OF PSYCHOLOGY

2018

NEUROPSYCHOLOGY: LECTURE 1 TOPIC INTRODUCTION WEEK 1: Tuesday 24th July 2018

What is Neuropsychology? 

Relationship between brain and psychological functions o Brain structure and function o Psychological function  behaviour

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Cognitive neuropsychology: o Information – processing approach o Models how things work in our brain  how do we think things through? o Infers the normal structure and function of the brain from the study of damage to the nervous system

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Clinical neuropsychology: o Application of neuropsychological knowledge to evaluate human behaviour as it relates to normal and abnormal functioning o Differential diagnosis: discrimination between disorders o Treatment planning: decisions based on the nature and extent of function o Rehabilitation: considering strengths and weaknesses of client to apply treatment strategies o Capacity/competence: evaluating a person’s ability to make reasonable decisions o Legal proceedings: document cause, nature and extent of dysfunction in personal injury cases

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Methods: Uses single case studies and “syndromes” approach: o Case studies: however has weaknesses in terms of generalisability (generalising someone’s problem to everyone else in the population) o Syndrome: collection of symptoms

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Investigating the Brain The Brain 

Structure: fine & gross o Single cells (neurons) o Brain structure and pathways o White matter: connects different parts of the brain (grey matter) to work together o Grey matter: where it happens (activity)

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Chemistry o Neurotransmitters o Psychoactive drugs

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Blood Vessels o Arterial (brings blood in) and venous

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Electrophysiology o Neuron: action potential o EEG: large number of cells

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Development o Normal and pathological

X-Rays/ Scans 

Plain X-Ray (2-D view) o Used for skull fractures, bones

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Contrast X-ray o Angiogram: dye injected into blood then x-rayed provides an image of blood vessels in the body/brain

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Computerised Axial Tomography (CAT/CT scan) o Multiple brain “slices” (3D picture) viewed at any orientation o Can detect differences as small as 1%

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Magnetic Resonance Imaging (MRI scan) o Measures magnetic properties of protons (water molecules) contained in the brain o Produces a 3D picture, similar to CT scan with a better resolution

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EEG (Electroencephalography)    

Measures electrical activity in the brain Uses metal electrodes to scalp Neurotransmitter firing  electrochemical processes Used to diagnose epilepsy, sleep disorders, coma, brain death

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Measured by frequency (speed) and amplitude (how high lines go) o o o o o

Beta waves: alert awake (high frequency, low amplitude) Alpha waves: relaxed awake/transitioning to sleep Theta waves: drowsy Delta waves: deep sleep (low frequency, high amplitude) Sleep spindles: asleep

ERP (Event Related Potentials)  

Changes in EEG patterns seen after presented stimulus Detects diseases affecting sensory pathways o Visual responses o Auditory responses o Somatosensory responses

PET Scan (Positron Emission Tomography)    

Reflects brain activity not structure (coloured imaging/heat scan map) Blood flow Glucose metabolism Resting state/functional scans

Functional MRI    

fMRI reflects brain activity not structure (like MRI) Detects activity of neurons by magnetic field Need baseline scans Ask someone to do something in an MRI machine

DTI (Diffusion Tensor Imaging)  

Imaging of white matter tracts Explores the connections between the different brain regions

MRS (Magnetic Resonance Spectroscopy)  

Measures metabolites/neurochemicals in the brain Can indicate cell death or dysfunction

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TMS (Transcranial Magnetic Stimulation)   

Non-invasively modulating brain activity Using magnetic pulses or pulse externally to facilitate or disrupt brain activity Used for depression and confirming lesions

Neuropsychological Assessment  

Behavioural investigation of brain functioning Person in context: o Individual History o Family/relationship history o Presenting problem o IQ measurement

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Assessment of: o Cognitive function o Sensori-motor function o Social/emotional function

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2018

NEUROPSYCHOLOGY: LECTURE 2 TOPIC FUNCTIONAL NEUROANATOMY WEEK 2: Tuesday 31st July 2018

Terminology: Directions and Sections   

Frontal section Sagittal section Horizontal section

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Dorsal - top Ventral – bottom Anterior - front Posterior - back

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2018

Layers of Protection The Skull    

Frontal bone: protects frontal lobe Partial bone: protects parietal lobe Occipital bone: protects occipital lobe Temporal bone: protects temporal lobe

The Meninges  Dura mater: outer layer  “hardest and toughest to break”  Arachnoid membrane: contains lots of blood vessels  Subarachnoid space: filled with CSF (between the arachnoid membrane and pia 

mater) Pia mater: softest lining of the brain

Empty Spaces: The Ventricles  Spaces in the brain that are filled with fluid: o Two lateral ventricles (right and left) o Third ventricle o Fourth ventricle  filled with CSF

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Stops the brain from collapsing in on itself Cushions it from the inside

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Cerebrospinal Flow (within the Ventricles & Meninges)  Cerebrospinal fluid: formed in the choroid plexus o Contains glia cells (ependymal cells  produce CSF)

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In the lateral ventricles as well as the third and fourth ventricles there is choroid plexus which produces CSF

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Arachnoid villi: where CSF leaves the brain

Blood Supply: Cranial Arteries  Brain is very hungry for oxygen!  Circle of Willis: where key arteries that provide blood for the brain meet together and form a circle

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Anterior cerebral artery: supplies blood to the dorsal surface of the brain Middle cerebral artery: supplies blood laterally to the surfaces of the brain Posterior cerebral artery: supplies blood ventrally/posterior to the medial surface of the brain

Basic Functional Neuroanatomy 

Structures of the brain: work from the bottom of the brain up

Hindbrain Structures   

Medulla: most inferior Pons: connects the cerebellum through the brain Cerebellum: “little brain”

Midbrain Structures 

Tectum: o Inferior colliculi  processes auditory info o Superior colliculi  processes visual info

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Tegmentum: o Covers the Pons

Diencephalon: Thalamus 

Thalamus: o Sends messages to the brain or to the body o Sensory motor relay station, o Has specific nuclei that relates to specific functions

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Hypothalamus: sits beneath the thalamus, hormones

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Thalamic Projections o Afferent: coming into thalamus o Efferent: coming out of thalamus

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SEMESTER TWO: CLINICAL ASPECTS OF PSYCHOLOGY

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Forebrain Structures Basil Ganglia  

Surrounds the thalamus Important for motor functioning/voluntary movement o Putamen o Caudate nucleus: “tail” o Substantia nigra

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Limbic System  Above the basal ganglia  Emotion  Cingulate cortex: “belt” wraps around  Temporal lobes: amygdala (process emotions), hippocampus (forms new memories)

Brain Hemispheres and Neocortex   

Two hemispheres Separated by the longitudinal fissure  largest sulcus in the brain Cortex/Neocortex: outer layer of grey matter o Gyri (gyrus): “hills” or “peaks” o Sulci (sulcus): “valleys” or “gaps”

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Corpus callosum: connects two hemispheres, white matter tract (collection of axons)

Dividing the Cerebral Hemispheres   

Central sulcus: divides frontal and parietal lobes Lateral (sylvian) fissure: divides frontal, parietal and temporal lobes Parieto-occipital sulcus: divides parietal and occipital lobes

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Hierarchical Organisation of Function 

Projection Map o Primary Areas: receive sensory input o Secondary areas: interpret inputs/organise movements o Association areas: modulate information between secondary areas

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Primary Areas o Anterior (motor)  Frontal lobe  motor functions o Posterior (sensory)  Parietal  body senses (somatosensory)  Temporal  auditory functions  Occipital  visual functions

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Secondary Areas 11

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o Receive input from primary areas o Interprets sensory inputs/organise movements 

Tertiary Areas (Association Cortex) o Located between secondary areas o Mediates complex activities (not sensory or motor)  E.g. memory, language, attention, planning  Wernicke’s or Broca’s area

Primary Motor and Somatosensory Cortices 

Motor Cortex o In the frontal lobe anterior to the central sulcus o Extends into the medial surface in the longitudinal fissure o Primary Sensory Areas: visuo-motor and object recognition processes o Contralateral  left hemisphere controls right side of body and vice versa

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Somatosensory Cortex o In the parietal lobe posterior to the central sulcus o Receives info about position of body in space and tactile stimulation

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Primary Sensory Cortices 

Visual cortex (V1) o Located in occipital lobe o Contralateral representation of visual fields o Retinotopic map

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Auditory cortex o Located in the temporal lobe o Bilateral representation of sound (both sides) o Tonotopic map  High frequency sounds: rostral/anterior  Low frequency sounds: caudal/posterior

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Olfactory and gustatory cortex o Olfactory bulb projects to limbic system and orbitofrontal regions ( behind eyes)  Represented ipsilaterally (same side) o Gustatory cortex in insula (hidden in the lateral fissure)

The Connectome 

Human Connectome Project 14

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o Maps brain pathways to identify them and variations 

Neocortical regions connected by four types of axon projections: o Short connections between one part of a lobe and another o Interhemispheric connections between one hemisphere and another (corpus callosum) o Connections through the thalamus o Long connections between one lobe and another

NEUROPSYCHOLOGY: LECTURE 3 TOPIC NEURODEVELOPMENT WEEK 3: Tuesday 7th August 2018

Lateralisation of Function Structural and Functional Brain Asymmetries  

Hemispheric specialisations, dominance; lateralisation Knowledge about lateralisation’s comes from: o Lesion studies o “Split brain” patients o Wada procedure

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Laterality (side) o Left and right hemispheres are lateralised and have different functions o However, both hemispheres participate in nearly every behaviour 15

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o Laterality affected by environmental and genetic factors  Cerebral organisation in some left-handers is different to right-handers  Females brain are less asymmetrical than males brains 

Left hemisphere o Produces and understand language o Controls movement on the right side of the body

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Right hemisphere o Perceives and synthesizes non-verbal information (e.g. music, non verbal information) o Controls movement on the left side of the body

Lateralisation and Asymmetry in Humans 

General counter-clockwise torque o Right frontal and left parieto-occipital regions are larger

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Right hemisphere  heavier, more white matter Left hemisphere  more grey matter

Understanding Lateralisation: The Corpus Callosum and Split Brain Studies  Corpus callosum severed because: o Congenital defects o Damage from stroke o Treatment for epilepsy (stops seizure from spreading to one side of the brain from the other, keeps seizure more localised)

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Acute deficits: o Tactile anomia: inability to name objects placed in their hands o Hemialexia: inability to comprehend words that are presented to one of the two visual fields (resolves in time) o Unilateral apraxia: problems with motor tasks of one side

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Chronic effects are more subtle

Split Brain Experiments  1960’s: Sperry & Gazzaniga (Patient Joe): reported effects of surgical bisection o

If optic chiasm is in tact you can direct visual field info from one visual field to the opposite visual cortex

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Left and right hemispheres can no longer share information  Left hemisphere: cant name objects presented to the right  Right hemisphere: CAN visually identify objects

Effects of Split Brain Operation  Face processing (Levy, 1972) o Could verbally identify the face seen by the right hemisphere 

Language (Zaidel, 1978) o Can display more complex material for longer periods o Right hemisphere: has basic word knowledge but cannot process complex grammar or put sentences together

Lateralisation of Language Function  Broca and Wernicke o Broca’s area: posterior frontal lobe o

 Speech production Wernicke’s area: superior posterior temporal lobe  Speech comprehension

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The right hemisphere does play a role in language comprehension e.g. understanding a joke

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Also important for non-verbal aspects of communication

The Wada Procedure and Language Function  Sodium amobarbital injected to produce a period of anaesthesia in one hemisphere in order to localise speech before surgery o Anaesthesia only lasts several minutes

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Causes unresponsiveness to contralateral visual field

Allows for the study of each hemisphere and determining lateralisation of speech

Neurodevelopment Neural Tube to Brain  

Day 18, after conception PNS and CNS begin to develop Day 26, ectodermal tissue at one end of the embryo is fused together to form the neural tube o Cavity in tube  ventricles o Anterior (front) of tube  brain o Posterior (back) of tube spinal cord

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Prosencephalon (Forebrain) o Telencephalon  Cerebral hemispheres o Diencephalon  Thalamus, Hypothalamus

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Mesencephalon (Midbrain)

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Rhombencephalon (Hindbrain) o Metencephalon  Pons and Cerebellum o Myelencephalon  Medulla oblongata

Neural Development 

Proliferation o Corticogenesis begins in 6th gestational week o Most concentrated period of neuronal proliferation

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Migration o Mostly complete by 18th week (where the cells travel where they need to be) o Six layers of neurons o Malformations associated with aberrant cell migration

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Myelination o Posterior to anterior process o Accounts for most increase in brain weight postnatally Axonal and dendritic development o Arborisation o Sensitive to environmental stimulation

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Synaptogenesis o Parallel process with above o Posterior to anterior process

Neurodevelopment: 5 to 20 years 

Pruning of synapses o Red indicates more gray matter, blue less gray matter o Gray matter wanes in a back to front wave as the brain matures and neural connections are pruned  Areas performing more basic functions mature earlier  Areas for higher-order functions (emotion, self-control) mature o Delayed cortical development in ADHD 18

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o Over-pruning in some disorders e.g. schizophrenia o Decline in gray matter may continue until age 60

Acquired vs. Developmental Neuropsychological Disorders 

Developing brain is vulnerable to insult during gestation and in early development

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Acquired disorders o Result from insult to, or infection of, the brain by environmental trigger  E.g. toxins, chemicals

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Developmental disorders o Disorders due to a deviation (abnormality) in normal brain development o May be genetic (inherited) o Some developmental disorders may be acquired through parental behaviour i.e. Foetal Alcohol Syndrome (or Foetal Alcohol Spectrum Disorder - FASD)

Foetal Alcohol Syndrome   

Foetal alcohol syndrome (FAS) Foetal alcohol spectrum disorder (FASD) Due to prenatal exposure to alcohol o How much not well understood

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Intrauterine growth retardation; low birth weight Characteristic facial dysmorphisms/abnormalities

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Physical conditions: o Heart defects; skeletal abnormalities

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Cortical & subcortical abnormalities: o Frontal cortex o Corpus callosum & WM o Cerebellar abnormalities o Hippocampus and basal ganglia

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Causes: o Intellectual disability o Executive dysfunction; ADHD 19

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o Sensorimotor impairments

Agenesis of the Corpus Callosum 

A congenital cause of the split brain, affecting the corpus callosum o Other commissures (anterior, hippocampal) often intact o Often associated with other structural abnormalities

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Frequently associated with cognitive impairments (as per FAS) Normal language and spatial skill lateralisation, however: o Difficulties with tasks requiring integration of information o Language: difficulties with rhyming words/sound alikes o Spatial: difficulties with jigsaws, puzzles, depth perception

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Theory of mind deficits psychosocial difficulties

NEUROPSYCHOLOGY: LECTURE 4 TOPIC LEARNING DISABILITIES, ADHD & TOURETTE’S DISORDER WEEK 4: Tuesday 14th August 2018

Specific Learning Disabilities 

Hallahan & Mercer (2001)  proposed 5 periods in the historical development of Learning Disability concept: o European Foundation Period (1800 – 1920)  Gall  attempted to describe what a learning disability was  Brain injury ...