Perception and Senescence Flashcards
Describe scanpaths of 1 and 2 months old and then an adult
1 month: 1st edge they see
2 months: start looking at inner details to identify
Adult: Look at central features to identify face
Where is the damage on the brain that causes prosopagnosia
Fusiform face gyrus (V4/IT)
What would you notice on a DTI MRI of someone with prosopagnosia?
Smaller inferior longitudinal fasiculus (ILF)
How else can someone with prosopagnosia identify a person
Hair style, Clothing, voice
True or false: Even a person with mild or moderate prosopagnosia will never recognize a face
False - mild or moderate can recognize with enough exposures
True or false: People with prosopagnosia only have trouble with faces
False - also cars and dog breeds. Anything where you’re only looking at a few same components to identify
Tell me about the Grandmother cell theory and if it’s accurate
Says that each face occupies one neuron. Not accurate anymore. Found that a face will activate the same combination of neurons though
Diseases that can lead to prosopagnosia?
Williams syndrome
Aspergers
How do you test for prosopagnosia?
Test using CG faces
True or false: Congenital prosopagnosia is common whereas acquired is not
True
What neurotransmitter causes decrease in vision with senescence?
Decrease in GABA
What’s affected by aging?
Dark adaptation Color vision Central vision Stereopsis Flicker Motion
What age does dark adaptation, color vision and stereopsis begin to falter?
Dark adaptation and stereopsis = 75ish
Colorvision totally gives out at 90ish
How much do pupil sizes change with age?
0.5mm per decade of life
How much worse is contrast sensitivity in older people?
3x worse than young adults
How much worse is stereopsis in older people than younger people?
1/2 as good as it used to be
If epileptic, why will you be more likely to get a decrease in motion perception when younger
Decrease in GABA for epilepsy!
What’s allesthesia?
See an object in blind field
Strange diplopia
What lobes account for allesthesia
Parietal if Balint’s syndrome
Occipital lobe
What’re the types of positive spontaneous visual phenomena
Allesthesia, visual distortion, kinetopsia, palinopsia and polyopia, phosphenes and photopsias, formed hallucinations
What’s visual distortion? What lobe do they occur in?
Alice in wonderland syndrome
Micropsia and teleopsia (Parietal)
Macropsia and pelopsia (Temporal)
What’s kinetopsia?
When you see movement that doesn’t exist. Can be in formed (rotating snakes) or unformed patterns (Migraine aura)
What’s palinopsia?What about polyopia? Where do these hallucinations come from?
Palinopsia: See things that should be gone from scene
Polyopia: see multiples of things. Can lead to trails of object
Caused by drug Trazodone
Phosphenes and photopsias
Phosphenes are unformed color/light blobbies
Photopsias are structured/tend to have a pattern
Causes of visual hallucination?
Dementia Seizure Drugs Parkinsons Sleep deprived Psychotic Charles Bonnet
Why does dementia cause hallucinations?
Poor perfusion. Just like with coffee
What’re hypnogogic and hypnopompic effects and what do they relate to?
Seizure induced hallucinations that happen right before sleep (Hypnogogic) or after waking (Hypnopompic)
What disorders cause hallucinations by causing decreases in dopamine?
Drugs (esp meth) Sleep deprivation
Why do you get hallucinations with parkinsons?
Poor fixations cause brain to do magic eye effect with world
Who typically gets Charles Bonnet syndrome?
Blind individuals
What causes psychotic hallucinations?
Increase in NTs
