Week 11: Higher Cognitive Functions Flashcards
What does asymmetry provide us with?
Language and other higher cognitive specialisations
How many lobes is the cerebral cortex/cerebrum divided into?
4 lobes - each lobe has specific location and functions
What are the 4 lobes?
Frontal lobe: thinking, conceptualisation, planning Parietal lobe: movement, orientation, calculation, recognition Occipital lobe: visual perception Temporal lobe: sound, speech processing, aspect of memory
Occipital lobe
Location: back of the brain Role: visual processing centre Primary visual cortex (Brodmann area 17) - important role in processing visual information
What are the clinical symptoms?
Cortical blindness (visual agnosia) Lack colour discrimination Homonymous hemianopsia
What is Homonymous Hemianopsia?
Visual field loss that respects the vertical midline (affect both eyes)
What is visual agnosia?
Impairment in the recognition of visually presented objects
What is the occipital lobe injury test?
1) colour matching test 2) recognition of famous people from abstract image
Parietal lobe
Location: above occipital lobe and behind frontal lobe Role: integrate sensory information through various senses
Left parietal lobe?
Gerstmann’s Syndrome
- right left confusion - difficulty writing - maths and language problems
Right Parietal Lobe
- neglect part of body and space (impair dressing and washing) - difficulty making things
What is hemispatial neglect?
Neglect the left side of visual field Neglect is more prominent and long-lasting after damage to the right hemisphere of the human brain (stroke)
What is the parietal lobe injury test?
1) Kimura Box test (sensorimotor task) 2) two-point discrimination test (somatosensory)
Temporal lobe
Location: side of the brain, below frontal and parietal lobes Role: processing sensory input into derived meaning for memory, language and emotion
Left temporal lobe
Language; disturb recognition of words (wernicke’s aphasia) Memory; impaired memory for verbal material
Right temporal lobe
Language: cause persistent talking Memory; impaired memory for non-verbal material (e.g. music and drawing) Prosopagnosia (face blindnesss) - inability to recognise faces
What are the test for temporal lobe injury test?
1) Wechsler Memory scale - revised (verbal memory) 2) Rey-complex figure (visual memory)
Frontal lobe
Location: front of brain, in front of Parietal and temporal lobe Role: emotional control centre and home to own personality: Motor function (e.g. loss of fine movement and strength of arms, hands and fingers) Spontaneity (e.g. little spontaneous facial expression) Language: e.g. Broca’s aphasia Problem solving, Memory, judgement, impulse control, social behaviour and sexual behaviour
Left frontal lobe
Pseudo-depression Language-related movements
Right frontal lobe
Pseudo psychopatic syndrome Non-verbal abilities
What is the frontal lobe injury test?
1) Wisconsin card sorting (divergent thinking) 2) finger tapping ( motor skills) - count average number of finger tap in a 10 second interval 3) token test (language skills)
What two tasks can domestic chicks perform simultaneously?
Find food (right eye discriminate grain from background) Be vigilant for predators (left eye monitor overhead predator)
Marmosets with weaker hand preference
Slower to react to a predator than those with a stronger hand preference
Fruit flies with an asymmetrical brain structure
Better to generate and retrieved long term memory
What did Paul Broca describe?
Patient understand language, but could not speak Could Whistle, utter few words, sing lyrics of melody
What did Paul Broca post-mortem show?
Lesion in the posterior region of frontal lobe (Broca’s area; Brodmann area 44 and 45)
What did Karl Wernicke describe?
Patient could speak but not understand language Ability to speak, hear instability to use or understand sentences
What did Karl Wernicke post-Mortem show,
Lesion in the rear Parietal/temporal region of the left brain hemisphere (wernicke’s area; Brodmann area 22)
What are the types of Aphasia ?
Global aphasia Mixed transcortical Broca’s Transcortical motor Wernicke’s Transcortical sensory Conduction Anomic
What is the WADA test?
1) hold both hands up and start counting 2) inject the dye into left common carotid artery and use angiogram to check which blood vessels will be affected 3) inject barbiturate (e.g. sodium amobarbital) into left common carotid artery 4) left hand drop and lose speech. Right hand still raised because left hemisphere control right Limbs and speech 5) once barbiturate quickly wears off, use of left ya d and speech is returned
Why is left hemisphere dominant?
Speech and short term memory in left hemisphere
What are the current techniques for functional neuroimaging?
Electroencephalography (EEG) - electrical activity Positron emission tomography (PET) - metabolic (18-Fluro-deoxy-glucose) - blood flow Functional magnetic resonance imaging (fMRI) -cerebral blood flow, blood flow, oxyhemoglobin vs deoxyhemoglobin ratio
Reacting a heard word
1) auditory cortex (hear the sound) 2) wernicke’s area (formulate what we are going to say) 3) Broca’s area (execute the plan of speech) 4) motor cortex (activation of speech)
Speaking a written word
1) visual cortex (read the word) 2) Angular gyrus (convert visual into auditory cortex) 3) Wernicke’s area (formulate what we are going to say) 4) Broca’s area ( execute the plan of speech) 5) Motor cortex ( activation of speech)
What are the neurotransmitters for the neurochemistry of speech and language disorder?
Dopamine Serotonin Acetylcholine
Dopamine
Parkinson disease Deficit in: Fluency Syntactic comprehension Prefrontal attentional Control Clarity and volume
What is improved in Parkinson’s patients?
Verbal
Fluency on levodopa
What is an example of dopamine D2 receptor agonist?
Bromocriptine
What does Bromocriptine improve?
Verbal fluency in Transcortical motor aphasia
Serotonin
Decreased levels are associated with depression Depression are associated with aphasia
What is an example of SSRI?
Fluvoxamine
What happens to children born to mothers using SSRI during pregnancy?
Greater risk of speech and language disorders
What has SSRI shown to improve?
Fluent aphasia (flow but no comprehension) or non-fluent aphasia (halting and effortful)
Acetylcholine
Found throughout the nervous system Greater cholinergic activity in left hemisphere than right (left temporal lobe)
What is an example of anticholinergic agent?
Scopolamine
What does scopolamine impair?
Verbal memory skills of storage, retrieval and working memory
What has significant anticholinergic effects?
Tricyclic antidepressants
What is an example of anticholinesterase inhibitor?
Galanthamine
What does Galanthamine improve?
Naming, auditory comprehension and verbal memory in individuals with fluent aphasia
What are Robert Plutchick’s 8 primary emotions?
1)Anger 2) Fear 3) Sadness 4) Disgust 5) Surprise 6) Anticipation 7) Trust 8) Joy
What has the brain have capacity to do?
Learn and remember emotional significance of a variety of stimuli and events (emotional valence)
Intrinsic attractiveness
Positive valence -joy
Aversness
Negative valence - anger/fear
What is a key limbic structure in emotional memory/expression?
Amygdala
What does lesion of amygdala cause?
Difficult learning association between stimuli and emotional states
What does the connections between cortical regions to subcortical limbic structures do?
Enable direct influence of complex sensory information in cortex to directly influence the limbic system
What does disruption to this connection cause (e.g. frontal lobe lesion)?
Inappropriate emotional and social behaviour in absence of intellectual deficits
What does cortex consist of?
Prefrontal and temporal cortex
What does limbic system consist of?
Hypothalamus, amygdala, hippocampus
What does the Brainstem autonomic nuclei consist of?
Parabrachial Nucleus, n. Solitary tract, dorsal motor nucleus of vagus
Cell bodies of dopamine system
Central tegmental area and substantia nigra
Cell bodies of serotonin system
Raphe Nucleus
Cell bodies of noradrenaline system
Locus coeruleus
What are 2 different types of primary injury?
Focal injury and diffuse injury
Focal injury
Coup (at site) Contrecoup (opposite side)
Diffuse injury
Diffuse axonal injury (widespread injury) Major cause of unconsciousness and persistent vegetative state
What do traumatic brain injury patients have problems controlling?
Own emotions (emotional lability) and recognising emotions of others
What are the physical reasons of emotions?
1) damage to the frontal lobes and limbic system which control our emotions and behaviour 2) frustrated with the effect of their injury
What are the psychosocial reasons for emotions?
1) communication 2) attention 3) memory 4) problem solving 5) personality changes 6) loss of inhibition
What is used to measure emotion recognition and neuropsychological functioning?
Complex Audio-Visual Emotion Assessment Task (CAVEAT)
