cognitive neuropsych - memory and perception Flashcards
Define what memory is
-Not a single function
-Dissociated from each other
-Independent
-Damage = amnesia
What are the different types of memory?
-Episodic = experiences
-Semantic = facts
-Working = short term/rehearsal
-Procedural = motor
What parts of the brain are associated with memory?
-Medial temporal lobe
-E.g. hippocampus, amygdala etc.
-More the hippocampus
Define anterograde amnesia
-Struggle to acquire new information that you have been presented with since the lesion
What types of memory does anterograde amnesia effect?
-Impaired declarative memory, both semantic and episodic
-Non-declarative memory isn’t affected, both perceptual and procedural
What disorder can this be caused by?
-Korsakoff syndrome
-Thiamine deficiency
-Can be due to alcoholism
-Bilateral generation of mammillary bodies
How can temporal lobectomy cause this?
-1950s
-Patients with intractable seizures
-Bilateral removal of the temporal lobes
What happened in the H.M. case?
-Had surgical bilateral removal of his anterior hippocampal regions at age 27
-Surgey successful for epilepsy
-IQ unaffected
-No personality change
How was H.M.s memory affected?
-Intact working memory e.gf. normal digit span and had normal rate of forgetting
-Semantic memory affected
-Couldn’t form new episodic memories
-E.g. language was frozen, date and age not updated, didn’t know new home address
Define retrograde amnesia
-Anything from before the lesion
-Distant memories are preserved
-More in amygdala, but still the MTL
How was retrograde amnesia shown in H.M?
-Childhood memories were the same
-Memories from right before lesion were lost e.g. forget death of favourite uncle
What areas play a part in vision?
-Occipital lobe
-Part of temporal and parietal lobe
-E.g. PVC, ventral and dorsal streams
What can be caused if vision is damaged?
-Agnosia
-Optic apraxia
Define agnosia
-Damage to ventral stream
-Inability to recognise
-Don’t know our perceptions
-Modality specific - can name an object through touch
What are the two types of agnosia?
-Apperceptive
-Associative
Define optic apraxia
-Damage to dorsal stream
-Deficit in spatial perception, visuospatial processing and visual guidance of action
What does apperceptive mean?
Unable to perceive the full object
-With intact low level processing
-Evidence = impairment in drawings
-See parts but not the whole
What does associative mean?
-Can perceive the object but can’t name it or recognise it
-Can copy figures
-Can’t draw from verbal instruction
What is prosopagnosia?
-Involves damage to fusiform gyrus
-Lower part of temporal/occipital lobe
-Right sided
What are the two types of prosopagnosia?
-Apperceptive prosopagnosia
-Associative prosopagnosia
What is apperceptive prosopagnosia
-Inability to perceive and cognitively process faces
What is associative prosopagnosia
-Inability to recognise or apply meaning to the face even though they can perceive it
