Week 12 (pt.2): Perception and Memory

What is perception

interpretation of sensation into meaningful forms

Computational aspects in object recognition include (3)

object constancy

view dependent/invariant

shape encoding

Object constancy varies in (3)

viewing position

how it is illuminated

object's surroundings

What is agnosia

inability to recognize objects when using a specific sense, even though the discriminative ability of that sense is intact

What are types of agnosia (3)

astereognosis

visual agnosia

auditory agnosia

What is tactile agnosia

inability to recognize objects by touch

What is the type of agnosia where the hearing is intact but cannot recognize sounds

auditory agnosia

What happens if theres a right lesion in auditory agnosia

interferes with interpretation of environmental sounds

What happens if theres a left lesion in auditory agnosia

unable to understand speech (wernicke's aphasia)

What are the two visual pathways

ventral stream and dorsal stream

What pathway is the "what" and gets input from parvocellular pathways; identification of objects

Ventral stream

If there is damage at the ventral stream what is it called

agnosia

If there is damage at the dorsal stream what is it called

optic ataxia, apraxia (loss of affordances)

What pathway is the "where"/"how" and gets input from magnocellular pathways; location of objects in space

dorsal stream

What stream involves spatial processing

dorsal stream

What stream involves object processing

ventral stream

What is visual agnosia

damage to the ventral pathway ; inability to recognize objects visually but can recognize by touch or sound

What is the type of visual agnosia that is unable to visually identify people's faces

prosopagnosia

What is apraxia

the knowledge of how to perform skilled movement is lost

Intact: sensation, muscle strength, coordination, understanding of task

Impairment in the ability to plan and carry out skilled, nonhabitual motor acts in the correct sequence; sometimes called DCD is known as

developmental dyspraxia

What is the type of apraxia that involves difficulty with dressing due to an inability to correctly orient clothing to the body

dressing apraxia

What is the type of apraxia that involves difficulty drawing, building, and assembling objects

constructional apraxia

3 types of limb apraxia

ideomotor

ideational

conceptual

Ideomotor is the inability to

carry our a motor command

Ideational is the inability to

create a plan for a specific movement; difficulty sequencing series of tasks

Conceptual is the difficulty of what

using tools

What are the complex perceptual functions (2)

visual perception and visuospatial perception

Ability to interpret information from visible light reaching the eye (form discrimination, figure ground) is known as

viasual perception

Ability to perceive or otherwise react to size, distance, or depth aspects of the environemt (spatial relations, topographical orientation) is known as

visuospatial perception

Form discrimination is the ability to

preceive differences among objects and positional aspects of objects

What are examples of for difficulties in form discrimination

unable to distinguish the difference between a square, rectangle and diamond

similar letters such as M and N

words such as hose, house, and horse

What is the ability to differentiate foreground and background forms or objects

figure ground

What is the term for relating objects to each or self

spatial relation

What is topographical orientation

determine the location of objects and settings and the route to the location

What are a few tests used to test visual perceptual skills (TVPS)

visual discrimination

visual foreground

visual closure

visual spatial-relations

What is body schema

an internal awareness of the body and the relationship of body parts to each other

What are the 3 classifications of memory

working

declarative (explicit)

procedural (implicit)

What classification of memory involves discrete information, depends on conscious reflection and cognitive processes and requires attention during recall

declarative

semantic: facts

episodic: events

What is procedural (implicit) memory

recall of skills and habits

What is working memory

short-term memory

What is amnesia

loss of declarative memory

What is retrograde amnesia

loss of memory of events BEFORE injury

What is anterograde amnesia

loss of memory of events occurring AFTER injury

What is the pathology of Alzheimer's Disease

reduced function and death of neurons; dysfunction of cells that line the blood vessels

What occurs later in Alzheimer's Disease

amyloid clumps together extracellulary & tau tangles intracellulary --> leads to impaired neuronal communication

What would happen after amyloid and tau impair neuronal communication

atrophy of cortex, amygdala and hippocampus

What are some symptoms of Alzheimer's Disease

forgetfulness

failure to produce/comprehend language

getting lost eaisly

What is the prognosis for Alzheimer's Disease

progressive, irreversible, 5-10 year life expectancy after diagnosis