Lecture 11 Flashcards
Describe the research study with M.P.
patient M.P., who had damage to his
temporal lobe which impaired his ability to name objects
- Cued in one of two ways before seeing a series of pictures in which they must
respond once they’ve found the target (indicated by the cue)
- Name: The name of the target object (‘cup’)
- Function: A description of the function of the target object (‘any item you
can drink from’)
- Cueing an object with it’s function produced better performance
What are affordances?
They made up of information that indicates what an object is used for, indicating a ‘potential for action’, or “…what the environment offers the animal, what it provides or furnishes.”
What is an action affordance?
action-
based information (the
affordance, or what it does,
and the action associated
with it) is automatically
activated during early stages
of processing
Describe the visual direction strategy of navigation
A visual direction strategy involves
keeping ones body pointed toward a
target
- Walkers simply correct their trajectory
when target drifts to left or right in their
visual field
Describe spatial updating
the processes involved with
keeping track of one’s position
as they move around within an
environment
What is wayfinding?
navigating to a destination that requires making a series
of turns
What are landmarks?
objects on the route that serve as cues to indicate where to turn
What happened during the training phase of the Hamid study?
Participants learned how to navigate a virtual maze (with pictures of common
objects serving as landmarks)
What happened during the testing phase of the Hamid study?
Particpants attempt to reach specific destinations within same virtual maze
environment
What critical comparison was drawn between these two trials?
fixation number on decision-
point landmarks as compared to non-decision-
point landmarks
Describe the museum study
- Participants were then presented with objects from three categories (while
being scanned) and indicating whether or not they remember each:
1. Decision-point landmarks
2. Non-decision point landmarks
3. Objects they were not shown during the experiment - For objects that were remembered,
those at decision-points were associated
with greater parahippocampal gyrus
activation than those at non-decision
points
What is topographical agnosia?
an inability to recognize landmarks
- Associated with damage to the parahippocampal gyrus
- Navigation deficits are a common symptom
F.G. navigated his hometown by relying
heavily on street signs (people are
adaptable and can often learn to use
whatever information is available when
conventional sources are lacking!)
What are place cells?
neurons that fire when in
particular locations (their ‘place field’)
What are grid cells?
similar in concept to place cells but have
multiple place fields that are systematically distributed
(and therefore follow a sort of spatial regularity)
What are head direction cells?
fire depending on direction animal if facing (recall
Gibson’s complaint about pilots not being able to turn their heads in lab-
based experiments!)
What are border cells?
fire when an animal is near the edge of an environment
Describe the monkey mirror neuron study
- Mirror neurons in the cortex of monkeys respond when a monkey grasps an object, as well as when an experimenter grasps an object
- Response to the observed action ‘mirrors’ the response of what happens when the monkey grasps something themselves
- Diminished/little response if object grasped less directly, e.g. by pliers
What are audiovisual mirror neurons?
They respond to stimuli associated with both seeing
and hearing action
- May help link sensory perceptions and motor actions
Describe reaching and grasping
Reaching and grasping are two of
the most common actions taken in
the environment and have great
adaptive value
- As with many topics related to
perception, entails more complexity
than we typically attribute - In part, this has to do with the
automaticity with which we can
engage in these behaviours
Differentiate between the role of dorsal and ventral streams in reaching
- Identifying the object (ventral)
- Positioning hand and fingers to
grasp (dorsal)
What is the parietal reach region?
Contains neurons that become active while reaching/grasping
Describe the monkey light grasping study
Monkey is briefly shown object with lights on, then lights turn off and a cue prompts the monkey to reach for object (Fattori et al., 2010)
- Requires monkey to not only remember location of object but also it’s form (to accommodate a hand grip)
- Specific neurons found that respond to trials requiring specific grips (image at right)
- Visuomotor grip cells become active when simply looking at objects
What is proprioception?
the ability to
sense body position and movement
Where are proprioception receptors located?
the elbow joint,
muscle spindle, and tendon help guide reaching/
grasping behaviour
