lecture 8 - partiel lobe Flashcards
look at where the partiel lobe is - diagram
back/behind
contrast between temporal lobe and parietal lobe
temporal lobe- tells you what things around you are , what memories and emotions are associated
frontal lobe - tells you what you can do with the things around you
what is gyrus responsible for
motor processing
primary somatosensory cortex responsibility
-feeling things on your body (touch, pain, etc)
Receives input from 20 types of receptors in skin: touch, tempera-ture, stretch, etc
■ contralaterally organized.
■ Electrical stimulations elicits sensations of being touched.
■ Lesions impair various tactile senses.
primary somatosensory cortex is _______ organised
contralaterally
________ ________ elicits sensations of being touched
electrical stimulations
the motor cortex has somatopic organisation
the distribution of areas of the motor cortex relating to specific activities of skeletal muscles, as mapped by electrically stimulating a point in the cortex and observing associated movement of a skeletal muscle in the face, the trunk, or a limb.
what is the homonculus
, diminutive fully formed human body
what does the parietal lobe do
-creates potential links between body and the world
-in at least 3 different ways
3 parts of parietal lobes
-left inferior parietal lobe
-superior parietal lobes
- right inferior parietal lobes
what happens when there are lesions to the superior parietal lobes
disorders of visually guided action
what is ataxia
-ataxia (failure to put in order)
-ataxia is unsteady and clumsy motion of the limbs, with poorly coordinated movements
what is optic ataxia
-how can this happen
optic ataxia specifies that the deficit occurs for movements under visual guidance, even through primary vision, motor control and knowledge about the limbs in space is present.
the inability to accurately point to or reach for objects under visual guidance with intact ability when directed by sound or touch despite normal strength. Therefore, a patient who can see an object may be unable to reach for it accurately until they physically contact it.
Happens after lesions to the superior parietal lobe, and affects the contralateral hand
what does the video with the patient that has optic ataxia tell us
-she can recognise objects
-can estimate size of object by scaling the distance between thumb and index finger
Only actions that require visual input are affected
- patients can touch their own body parts.
- reaching to an object from memory is often better
.- can perform well known gestures.
- can pantomine using objects
what does the video tell us about patients with optic ataxia
-they can recognise objects- vision?
-can estimate size of object?
-which actions are affected
-patients can recognise objects- this means their vision is intact
-can estimate the size of the object by scaling the distance between thumb and index finger - means their spatial perception is intact
-only actions that require visual input are affected
-patients can touch own body parts
- reaching to an object from memory is often better
.- can perform well known gestures.
- can pantomine using objects
not a disorder of vision or action
OA- not a disorder of ______ or ______
vision or action
-its more a disorder of visually guided hand movements - coordination?
-hand eye coordination
-coordination of limbs relative to objects
-uniting visual and motor skills to allow hands and sight to work together
lesions to the left inferior parietal lobe can cause
-disorders of learned action, skilled action
-for humans / organisms to use tools they need to know how to ____ them.
-gestures can also be seen as tools- how?
-use (this is learning)
-gestures can be seen as tools, you have to learn them to use and understand them
define apraxia
-apraxia means ‘without action’ and ideomotor means ‘movement ideas’
-altogether this means without action due to lack of movement ideas
-loss of the ability to execute or carry out learned purposeful movements, despite having the physical ability to perform the movements
what are patients with apraxia able and unable to do
-unable to use tools, to pantomime the use of imaginary tools and to recognise pantomimed actions. most cant even imagine the movements
-able to effectively grasp objects, touch parts on their own body, so again its not a problem with motor control
lesions to the right inferior parietal lobe can cause
disorders of attention and looking
william james idea of attention
-‘the taking possession by the mind in clear and vivid form, of one out of what seem several simultaneously possible objects or train of thought… it implies withdrawal from some things in order to deal effectively with others’
right parietal lobe hosts the system of attention etc
-the card changing trick
The notion that we are conscious of all aspects of the world in front of us is an illusion.
We have to constantly scan the scene to stay conscious of its contents.
We only store where things are so that we can look at them again if their details are important.
eg card changing trick
what is hemispatial neglect
-the effect this has on patients
after damage to right inferior parietal lobe
: forgetting” one side of space (usually left).
failure to orient toward, explore and respond to stimuli presented on the contralesional side(typically the left hemisphere)
Happens even when stimuli appear in isolation or for sustained periods of time.
Neglect patients often only talk to people on their right, bump into objects on their left, but are completely unaware of their deficit.
what does the right hemisphere control (parietal lobe)
-orientation in space
or movement of the eyes
hemispatial neglect- what is it literally
usual control of movement of eyes has a deficit in visual action because patient ‘forgets’ that there are looking opportunities to the left side of space
Imagination is controlled by the same system; imagination is not abstract but seems to rely on a spatially accurate mental image that we scan with imagined eye movements.
the parietal lobe links the body to the world in 3 ways :
1: where you can look
2: which visually guided actions you can perform with the objects around you
3: which learned actions you can perform with them
