Wk4 Space & Action 2 Flashcards
representation of the body is constructed in __
, or by, the parietal lobe
what are arguably key properties of the representation of the body?
it is dynamic, changeable, and plastic
gravitational effects on misperceptions of the environment are stronger in patients with ___ 2
unilateral vestibular loss
unilateral brain damage
In Lopez and Blanke’s paradigm what is the effect of sitting down and why?
Px misperceive a bar’s orientation from standing, to sitting, to lying.
Sitting disrupts their sense of gravity given by their feet, through the plantar reflex.
why is an upright stance an optimal position for gravitational perception?
the head is aligned with gravity, placing the otolith receptor in an optimal orientation for coding gravitational acceleration.
what are two sensory sources that allow us to process body position with respect to gravity?
gravitational acceleration from otolith receptors
mechanoreceptors of the plantar sole (feet)
how does lying down affect body perception? what are two converging reasons for this?
lying makes you more likely to misperceive and misintegrate sensory and environmental cues with respect to the body.
otolith receptors are in a less optimal position to encode gravitational acceleration
the feet dont contact the floor, so there is no info from movement receptors
processing the body’s position with respect to gravity is ___ and __
highly dynamic
always being updated by sensory changes
what is a body schema?
a representation of the body that is independent of sensory inputs from the environment
in what strange ways can phantom limbs be perceived? 2
the limb can stretch and foreshorten
it can also protrude at weird angles
phantom limbs add support/ suggest that __
we have a fundamental body schema which can be developed over time
how did ramachandran explain that a patient was feeling sensations in his amputated hand when his cheek was stroked?
the face portion of the somatosensory map merged/took over some of the area of the lost hand
what are two phenomena elicited by the rubber hand illusion?
proprioceptive drift
subjective ownership
in brief how is the rubber hand illusion created?
an experimenter synchronously stimulates both a rubber hand and the participant’s real, hidden hand
what does proprioceptive drift reveal about processes of body representation?
an updating of the neuronal representations of the body can occur in real time
how would you know that proprioceptive drift has occured in the rubber hand illusion?
where the participant reports their hand is will be shifted away from its actual location, towards the fake hand
even a ___ is capable of eliciting the rubber hand illusion
block of wood
what are some ways that affective / physiological responses have been influenced by subjective ownership in the rubber hand illusion? 3
blood assays reveal changes in histamines
temperature of the real hand can drop when Px perceive the fake hand as their own
there is a startle response to a knife attack on the fake hand (where Px snatch their real hand away!)
what was found by performing the rubber hand illusion on children with autism? and what does this suggest?
delayed induction of the illusion
suggests a multisensory integration deficit that is occurring in autism
what does the rubber hand illusion suggest about vision and proprioception?
vision is more dominant / has higher priority than proprioception, when forming a body representation
what fact shows that people’s internal representation is flexible and extensible?
it can incorporate non-animate objects, such as tools, and make them part of the self representation
what is an affordance?
the feature / quality of an object that allows an action to happen
a graspable object in the environment elicits what two types of action?
wanted/appropriate, which are released and enacted
unwanted/inappropriate which are inhibited
what idea do affordances suggest?
there is a link between our actions and the physical environment – are we ‘predisposed’ to work with tools
