Lecture 16: Spatial Cognition

Topographic memory

The ability to move from one landmark to another, relying on topographic knowledge, route following, and a response strategy.

Weakness: removing landmark

Cognitive map

A mental representation of the spatial environment that employs survey knowledge, piloting, and a place strategy.

Body space

A neural map of the surface of the body and everything with which it comes into direct physical contact.

Grasping space

The area immediately surrounding the body (also known as peri-personal space) that is monitored by the ventral visual field.

Distal space

The spatial realm through which the body travels, monitored and processed primarily by the dorsal visual field.

Time space

The subjective cognitive representation and awareness of the past, present, and future.

Egocentric reference frame

A viewpoint-centered spatial representation system in which object locations are encoded in relation to the observer (observer-dependent).

Hippocampal Volume

HPC has been show to be larger (more neurons) in caching bird species (hide surplus food for later in winter), relative to non-caching species

→London taxi drivers may also have larger HPC than non-specialists.

Allocentric reference frame

A world-centered spatial representation system in which the locations of objects are encoded relative to other objects and environmental features, independent of the observer's viewpoint.

Dead reckoning (path integration)

The process of continuously updating one's present position based on self-motion cues such as speed, direction, optic flow, vestibular input, and proprioceptive signals.

→Sailors historically relied on this ability

Morris water maze (Morris water task)

A spatial navigation assessment in which subjects navigate through a circular pool using distal cues to locate a submerged, hidden platform or sensor.

→ Non-human animals and humans can use distal landmarks to accomplish this

Test of spatial memory

A neuropsychological evaluation in which subjects name and estimate prices for an array of tabletop objects and are subsequently tested on their ability to accurately reproduce object locations after short and long delays.

Damage to left HPC (spatial memory test)

subjects perform similar to controls - able to produce the location of object in original presentation

Damage to right HPC (spatial memory test)

subjects have significantly more errors in producing original location of objects.

Visualization tests

Neuropsychological assessments (such as paper folding) that evaluate an individual's capacity to mentally rotate, manipulate, retain, and recall visual objects.

Orientation tests

Neuropsychological assessments (such as mental rotation) designed to evaluate a subject's understanding of how elements are arranged within a visual scene that changes orientation.

Topographic disorientation

A gross clinical disability in navigating or finding one's way using salient environmental cues, often resulting from topographic agnosia or spatial amnesia.

Right hemisphere function (one of them)

Spatial abilities associated with understanding and processing visual information.

Topographic agnosia

Inability to navigate using salient environment cues, even in familiar environments.

Retrograde spatial amnesia

a condition where individuals lose the ability to navigate or recall previously known environments or routes due to memory loss.

Anterograde spatial amnesia

An impairment characterized by the inability to navigate in or learn the layout of novel spatial environments following neurological damage

Developmental topographic disorientation

A condition characterized by a lifelong inability to navigate environmental surroundings, linked to a lack of functional connectivity between the retrosplenial cortex and the parahippocampal place area.

Egocentric disorientation

A spatial syndrome where a patient has difficulty perceiving or representing the relative location of objects with respect to the self, associated with unilateral or bilateral damage to the posterior parietal cortex.

→ can locate objects with visual guidance but not with eyes closed.

Heading disorientation

An impairment in which a patient can identify landmarks but is unable to represent their direction of orientation with respect to the environment or plan a course, associated with damage to the right posterior cingulate cortex.

Spatial distortion

An aberration in the spatial perception of oneself, which can manifest as out-of-body experiences; linked to strokes affecting the medial parietal or posterior cingulate cortex.

Landmark agnosia

An inability to recognize and use prominent environmental landmarks to orient oneself, typically caused by lesions in the medial occipital lobe including the lingual, fusiform, and parahippocampal gyri.

Anterograde disorientation

A syndrome where a patient can successfully navigate familiar environments learned before the injury but cannot recognize novel landmarks or learn new environmental layouts, associated with damage to the right parahippocampal gyrus.

Retrosplenial cortex

A cortical structure located immediately posterior to the splenium of the corpus callosum (comprising Brodmann Area $29$ and Area $30$) implicated in heading orientation and navigational connectivity.

Ventral Stream contribution

Projects from occipital lobe to frontal lobe to mediate perception

Has three projections

Three projections from dorsal stream

1. Projection to primary motor areas mediates grasping and reaching

2. Projection to secondary/supplemental motor areas mediates eye movement

3. Projection to temporal lobes is important for spatial navigation

Temporal lobes and spatial behavior

Different research suggests a specific role in spatial navigation or more general role in memory that can impair spatial functions.

Ex.

• ventral stream projects to temporal lobe to mediate perception

• temporal lobe integrates info about body (e.g., autonoetic awareness) and external world to guide movement to targets.

HOWEVER, roles are not clear.

Hippocampus/Entorhinal cortex + spatial behavior

• Dorsal and ventral streams coverage on hippocampus and entorhinal cortex

Damage to hippocampus

…and surrounding areas associated with anterograde spatial amnesia, but not retrograde spatial amnesia

Place cells

Spatially tuned neurons situated primarily in the hippocampus that fire selectively when an organism enters a specific location within an environment.

Head direction cells

Neurons located predominantly in the postsubiculum that discharge whenever an animal points its head in a specific preferred orientation, regardless of its body position or movement path.

Grid cells

Spatially firing neurons located in the medial entorhinal cortex that discharge at regularly spaced nodes, tiling the terrain into an array of equilateral triangles.

Egocentric boundary-vector cells (border cells)

Spatially tuned cells that fire specifically when an animal is at a particular distance and direction relative to environmental borders or boundaries.

Time cells

Neurons that fire at specific successive moments during a temporal interval, encoding the temporal dimension of experience.

Scene construction theory

A theoretical model proposing that the hippocampus synthesizes inputs from cortical regions to generate spatially coherent scenes supporting navigation, episodic memory, imagination, and future thinking.

Theory of mind

The cognitive capability within social cognition to utilize constructed scenes to attribute mental states—such as desires, beliefs, intentions, and knowledge—to others across past, present, and future timelines.