Neuropsychology Flashcards
Neuropsychology
Relationship between brain and behaviour Alternative terms Biopsychology Biological psychology Physiological psychology Focus: normal/healthy brain structure and function
Examines Gross anatomy of the brain Electrical processes (nerve impulses) Chemical processes (neurotransmitters) Brain development and ageing
Clinical neuropsychology is
neuropsych meets clinical psychology
> Essentially what clinical psychologists do, but with different clients
Clients: have some form of brain damage or dysfunction
Brain damage can be congenital - resulting from problems that occur during the brain’s development (foetal development)
> Damage can be acquired at any stage of life - during infancy, childhood, adolescence or in the adult years - through trauma or disease
Developmental disorders - examples
Congenital hypothyroidism
Child is born with an underactive thyroid gland (this gland regulates metabolic rate
and brain development)
Cerebral palsy
Caused by trauma to the brain during foetal development or at birth, leading to motor and postural problems
Acquired disorders - examples
During childhood - e.g. injury to the head (fall, bicycle accident), brain infection
(encephalitis), epilepsy
Adulthood - e.g. tumours, strokes, degenerative diseases
Functions affected by brain damage can be..
Perceptual skills Motor abilities Cognitive abilities, e.g. Attention Language - speech and writing Memory Visuo-spatial skills Problem-solving skills Etc. Mood/emotional functioning Depression Anxiety Behaviour Aggressiveness Impulsivity Inappropriate behaviour All of which affect psychosocial functioning Ability to live independently Self-care Work/study Maintain friendships Manage finances Resume driving
Etc.
Neurons
Comprise of cell bodies and axons
In CNS, axons surrounded by glial cells, which form an insulating sheath - myelin
Electrical events
Info transmitted along axons via electrical event - action potential
Action potentials move between gaps in myelin, leading to faster transmission
Chemical events
Information transferred between neurons via chemical events
Neurotransmitters are released at the synapse, enabling messages to be transferred from one neuron to the next
Neurotransmitters: dopamine, serotonin, acetylcholine, etc.
‘Brain damage’ involves..
death of cells and/or disruption to their functioning
Death of cells
Variety of causes
Lack of blood, oxygen, glucose
Diseases or physical injury
Alzheimer’s disease or Parkinson’s disease
Disruptions to neuronal functioning, affecting
Electrical transmission
e.g. multiple sclerosis - affects myelin
Neurotransmitters
e.g. Parkinson’s disease - substantia nigra (in midbrain), reduced dopamine
Neuronal functioning
Damage differs in a number of ways
Diffuse vs. focal
Static vs. progressive
Diffuse damage
Not concentrated in any specific region
Includes
Diffuse axonal damage (DAI) - affects axons/white matter
Diffuse vascular damage - affects blood vessels, causing diffuse widespread
bleeding in small blood vessels
General term: diffuse brain damage (DBD)
Leads to general/wide-reaching cognitive problems
Slower responses, less efficient information processing
Focal damage
> Concentrated in specific areas
Damage/’lesions’ often more visible and more easily detected using brain scans
Varies in size/amount
Usually leads to more specific cognitive problems, which vary according to the location of the damage
‘Static’/single/one-off events
Acute event
Examples:
> Traumatic brain injuries - e.g. motor vehicle accidents
Stroke
Carbon monoxide poisoning
Most damage occurs around the time of the injury/event; in the acute/early stages
Condition stabilises, improvement/recovery can occur
Dura
hard, solid, thick protective layer of brain
Arachnoid layer
fibrous membrane with blood vessels and cerebrospinal fluid (provides cushion)
Pia matter
thin layer that closely follows the outside of the brain
Sulci
grooves/fissures
Gyri
convolutions/folds (Sulci and Gyri provide important landmarks for functionality)
Association/secondary areas
> Adjacent to primary processing area
Process information from primary processing areas
Higher-order processing
Located next to primary areas
Tertiary areas
> Between association areas
Combine info from association areas - higher-level processing
Complex – from a range of different sourse
eg. Language and memory
Posterior regions
Occipital, parietal and temporal lobes
function: Input
Anterior regions
Frontal lobes
Function: Output
Regions connected by
> Short fibres - connect one part of a lobe to another
Association fibres - connect lobes located on the same side of the brain
Commissures - fibres that link two hemispheres (eg, corpus colosseum)
Visual association area
> Adjacent to primary visual cortex
Receives info from primary visual cortex
Synthesises different types of visual information with memory
Undertakes higher-level visual processing, enabling us to perceive and recognise objects
Primary visual cortex
Cortical blindness
Retina is intact but the visual processing is damaged
Blindsight
optical lobe damage cont.
> Extensive damage (on both hemispheres), person reports being blind but still has very basic visual processing on the subcortical level (subconscious)
> Not common
Can perform basic visual tests but may say it was a guess (can differentiate an x over an o)
Visual anosognosia
optical lobe damage cont.
Anosognosia = lack of awareness
Cortically blind person denies being blind, and tries to behave as if sighted
Confabulation - ‘make up’ excuses why they bump into things (not deliberately lying)
>The part of the brain that knows they are blind is damaged
Visual agnosia
Visual association cortex damage (optical lobe damage cont.)
Agnosia = loss of knowledge
Problems specific to visual processing
Can recognise things using other senses - sound, touch (this is because tactile information processing not damaged)
Person may perceive the object in its parts (piecemeal), or
May perceive the whole object, but not recognise what it is
There are different types of visual agnosia
Object agnosia
Inability to recognise common objects
Colour agnosia
> Unable to distinguish between colours or to relate colours to objects
Black and white vision
Colour visuon is intact
Prosopagnosia
Inability to recognise faces
Parietal lobes
Primary somatosensory cortex
> Located along post-central gyrus
Receives somatosensory info - e.g. touch/pressure, temperature, pain, limb position/movement
Info received from the opposite side of the body (contra-lateral input)
Highly organised
Somatosensory homunculus
Hands and face are overrepresented proportionate to their size - because it is more important to have more sensory receptors on these things…
Somatosensory association area
Adjacent to primary somatosensory area
Integrates sensory info
Combining and analysing sensory info
Recognition of objects by touch alone
Tertiary processing area
Adjacent to Somatosensory association area
Integrates different types of sensory information
Visual, auditory, tactile and spatial information processed together
Tactile agnosia (astereognosis
Inability to recognise things via touch
Visual neglect/hemi-inattention
When a person neglects one side of space as if it doesn’t exist
Person does not pay attention to the opposite side to where the damage is
e.g. only dresses one side of their body, or shaves one side of their face
Doesn’t physically know that the “opposite side” of the world is there - harder to
compensate for as opposed to blindspots
Fail to attend one area of space
Apraxia
Disorder affecting voluntary movement
Not attributable to: Motor/physical problems Problems comprehending Motivation
Dressing apraxia
> Specific form of apraxia
Person unable to coordinate movements to dress,wave goodbye, fold a letter, light a match
omit appropriate actions or fail to make any movement
Temporal lobes
Important and varied functions
Auditory processing
Language
Memory
regulating emotional reaction
Primary auditory cortex
> Located on superior temporal gyrus, adjacent to lateral fissure
Receives auditory information
Allows us to hear – both verbal and non
Auditory input is
Ipsilateral (same side) and
Contralateral (opposite side)
Mostly contralateral input
Organised according to tones - tonotopically organised
Anterior - high frequency
Posterior - low frequency
Damage can lead to different affects based on this
Auditory association area
Right
Specialises in analysing non-verbal sounds
Music, other day-to-day sounds
Auditory association area
Left
referred to as Wernicke’s area (all right handed people- ¬97% , most left handed people)
Specialises in processing speech
Comprehending speech
Auditory association area
Wernicke’s aphasia (more common)
Aphasia means a language problem
May also have pure word deafness
Unable to comprehend speech
Have fluent (lots of output) but meaningless speech
Unaware that their speech is incomprehensible
Cannot repeat words or sentences Might be able to read depending on how much damage there is - but may still struggle to attach meaning to words
Auditory association area
Right-sided damage
Problems recognising non-verbal sounds
e.g. if there is a fire alarm you wouldn’t recognise that you should evacuate
Problems with processing music (amusia)
Is typically less disabling than left side due to our dependence on language
Motor cortex
> Located on pre-central gyrus, anterior to central sulcus
Controls muscles/movement
Projections to neurons in spinal cord, which project to muscles >Highly organised
Contra-lateral control
Motor homunculus
Pre-motor cortex
Located anterior to motor cortex
Selects, sequences, programs complex movements
Typing, speaking, ride bike, writing - pre-motor cortex ensures that everything happens in the right order
Broca’s area (left hemisphere)
Pre-motor cortex
Specialised for movements involved in speech and writing
Prefrontal cortex
Last part of the brain to fully mature (25ish)
Rich connections with all other areas of the brain
Responsible for very high level functions: ‘executive functions’
Executive functions - impact on everything
Intact executive functions needed to function independently
Responsible for
Working memory/attention
Integrating information
Regulating behaviour
Formulating plans
What steps we need to do, in what order
Executing plans
Monitoring and modifying
If it looks like what we’re doing is not going to achieve what we want, we modify what we do
Behavioural regulation
Ability to start, stop and change, as needed – flexibility
Cannot learn from experience
Perseveration - repeat a response when no longer appropriate
Do not adapt to change
Cannot inhibit behaviour
Fail to comply with instructions
