Lecture 16 - Spatial Navigation Flashcards
(37 cards)
When were cognitive/spatial maps initially proposed?
Tollman was the first to suggest cognitive/spatial maps and provided evidence for this using rats in the 1940s.
There is evidence for place cells in which area of the brain?
The hippocampus.
Aside from place cells, what other cells are important for creating a cognitive map?
Are these cells all in the hippocampus?
Grid cells, head direction cells, and border/boundary cells.
No. Whilst place cells are found in the hippocampus, these other cells are found in other areas of the brain, but are close to the hippocampus.
A lot of work around understanding how we engage with navigation and form cognitive maps is based on experiments using rodents.
Why is it difficult do measure navigation in humans and how is it currently done?
With rodents neurons and cortical activity can be measured directly using electrodes. Due to ethical reasons the same cannot be done with humans. This means when we want to measure brain activity in humans we need to use more indirect measures, such as fMRI, which are less accurate more limiting.
Where in the brain are ‘scenes’ processed (proposed area)? Scenes include landscapes, rooms etc.
The parrahippocampal place area (PPA). Proposed by Kanwisher.
What aspects of a scene is the PPA encoding?
The PPA encodes for global geometry of a scene (that is, the layout of a scene as dictated by the larger structures, or lack there of, in the scene), not the objects themselves.
The PPA encodes for the global geometry of a scene not the objects within the scene.
True or False?
True.
There is a broad range of evidence to support this statement.
What areas encode for the objects within a scene?
The areas in the brain that responsible for encoding for/processing information regarding objects in our visual field are the Lateral Occipital Complex and the fusiform gyrus.
What would a person with damage to the PPA experience a scene as?
People with damage to the PPA report being able to see and identify objects within a scene, but do not have a sense the layout of the scene, i.e where these objects are in relation to one another.
What do border/boundary cells encode for/what aspect of vision are they responsive to?
Border/boundary cells encode for information about how far away we are from objects/landmarks.
The border/boundary cells in the hippocampus are not playing a role in recognising objects/landmarks, but rather are only encoding for information in regards to how far from a landmark/object one is.
True or false.
True.
Where in the brain are the border/boundary cells that encode for distance from and between objects/landmarks?
Border/boundary cells are located in the hippocampus.
There has been evidence to show that humans also have place-responsive/place cells in the hippocampus.
True or false.
True.
What is encoded in the retrosplenial complex?
Allocentric heading
What is allocentric heading and where in the brain is this aspect of vision encoded/processed?
The Retrosplenial Complex.
What is a euclidian distance and what is a path distance?
Hint: as the crow flies
EUCLIDIAN DISTANCE refers to the distance as the crow flies.
PATH DISTANCE refers to the distance a route will take.
Are euclidian distances encoded in the posterior or anterior region of the hippocampus.
The anterior area of the hippocampus.
Where are path distances encoded? The posterior or anterior are of the hippocampus?
Posterior.
Do euclidian distances correspond to a cognitive map?
Yes.
What is encoded in the posterior parietal cortex?
In the RETROSPENIAL CORTEX it is thought that allocentric heading.
Taxi drivers in London that had been working for a long time showed increases growth in their hippocampus. What does this suggest about the hippocampus.
What areas of the hippocampus were found have increased volume and what area had decreased volume?
Did London bus drivers show this same change in hippocampus volume?
The hippocampus is responsible for spatial navigation and cognitive maps, at least partially.
The anterior of the hippocampus had decreased volume and the posterior had increased volume.
No.
What is Unilateral Spatial Neglect?
Unilateral Spatial Neglect is the contralateral disturbance or absense of visual awareness of one side of the visual field.
Why is unilateral spatial neglect caused mostly by damage to the right parietal lobe and why right-side spatial neglect rare?
The right hemisphere tends to be more responsible for spatial awareness and spatial encoding.
There is redundant processing of right visual spatial data in the left hemisphere, along with processing the right hemisphere as well, whereas left side visual data is only processed in the right visual field. This means that it is rare for unilateral spatial neglect of the right visual field.
What is the frequency map of the basilar membrane in the cochlear?
Higher frequencies are mapped toward the base of the basilar membrane and lower frequencies are mapped toward the apex of the basilar membrane.
