Cognitive maps, perception

Cognitive Maps

Are a representation of space that describes distances and directions which includes knowing where you are within this map.

Two types of cognitive maps

Survey representations and route representations

Survey Representations

Birds eye view, using external references such as north/south

Route Representations

A path view relative to self. (ex. turn left after captain’s den to reach CNU)

How do people differ

People differ in how they navigate a spatial scene and not everyone creates a cognitive map

Features of cognitive map

1. Shortcuts 2. landmarks 3. integrating routes to create a survey (bird’s eye view) map

What brain regions do cognitive maps use

Research suggests hippocampus may create a map (place learning); while basal ganglia (“striatal system”) creates a route (response learning)

Dual solution paradigm

Meaning that people can use a mixture of the two strategies

Shortcuts rely on what brain region?

Hippocampus

Familiar routes rely on what brain region?

Basal ganglia (“striatal system”)

What future research needs to be done on cognitive maps

Research needs to keep in mind how they are defining features of a cognitive map and be prepared to test for individual variation

Define perception

Is an experience resulting from stimulation of the senses

What is perception based on

What we sense, past experiences, expectations

Types of processing

Bottom-up processing and top-down processing

Bottom-up Processing

Perception comes from stimuli in the environment. Parts are identified and put together and then recognition occurs.

Top-down Processing

People construct perceptions using information based on knowledge and expectations. We use our knowledge to inform our perceptions

Helmholtz’s theory of unconscious inference

Perception is based on unconscious assumptions about the environment based on past experiences.

Likelihood Principle

We perceive the “most likely” objects based on expected patterns

Object Permeance

Babies as young as 4 months are aware of how objects should behave relative to other objects. Research done by Jean Piaget. A behavioral measure for a young participant who cannot speak is how long they look at something

Measure a behavioral reaction

Recording behavioral response or reaction to a situation or stimulus

Measure reaction time

Amount of time it takes to respond to a stimulus. Amount of time it takes to complete a task. Frequently called “response time” or RT.

Measure performance

How many correct or incorrect? Measure “self-corrections”. Behavioral measures are frequently paired with other methods.

Summary of perception

Perception is an experience resulting from stimulation of the senses. Perception is based on a combination of (i) what we sense (ii) past experiences and (iii) expectations. Perception can occur through bottom-up and/or top-down processing. Perception (as well as other forms of cognition) can be measured by multiple behavioral measures, which include three broad categories: reaction, time, and performance.

Parts of the brain

Sensory Common Thread

Each sensory modality has its own pathway but they all follow a similar pattern. Information closest to sensory information “home” (known as primary sensory cortex), the more basic. Information becomes more complex as we move down the path of sensory processing.

Two primary pathways in sensory receptor

Dorsal (where) and ventral (what)

Visual Processing Pathway

Primary visual cortex (V1) is the “sensory information home”. Basic visual information could be lines and colors. More complex visual information would be whole objects, faces, etc.

Visual Processing Pathway

“Where” visual stream: spatial processing, location, movement, spatial relations. “What” visual stream: object processing, color, texture, detail, shape, size.

Summary of “Where is perception”

Each of the five senses has a primary sensory cortex (a “home”). For visual processing this is the primary visual cortex (aka V1). Sensory pathways follow a similar pattern. Upon entering the brain, they travel to their respective primary sensory cortex, then information travels along (at least) two pathways: the dorsal and ventral pathways.

Gestalt School of Thought

The whole is greater than the sum of its parts

Gestalt laws of perception

A collection of principles (or laws) that attempt explains how we perceive (organize & interpret) visual information into unified wholes. Law of good continuation, law of good figure, law of similarity, law of familiarity, law of proximity, law of common fate

Law of Good Continuation

Applies to points that, when connected, result in straight or smooth lines that are seen as belonging together. Lines tend to be seen as flowing the smoothest path. Objects that are overlapping by other objects are perceived as continuing behind the overlapping object.

Law of Good Figure

Aka Law of Simplicity. Every stimulus pattern is seen so the resulting structure is as simple as possible. In our example we see five circles in (a) but (b) is perceived as a more complex array of nine objects

Law of Similarity

Similar things appear grouped together.

Law of Familiarity

Things are more likely to form groups if the groups appear familiar or meaningful.

Law of Proximity

Things near each other appear grouped together.

Law of Common Fate

Things moving in the same direction appear to be grouped together.

Optical Illusions

When we visually perceive something that is different from our reality. The gestalt laws can be used to help describe how our brains create these optical illusions.

Visual Processing and Perception

Bottom-up: taking in visual pattern. Image is perceived as the same pattern. Top-up: required to “override” sensory input and to systematically count the dots. If this were a behavioral experiment, we could measure how long it takes to do the task and/or accuracy of responses.

Perception in occipital lobe

Law of Familiarity: Things are more likely to form groups if the groups appear familiar or meaningful. Law of Good Continuation: Applies to points that, when connected, result in straight or smooth lines that are seen as belonging together. Law of Good Figure/Simplicity: every stimulus pattern is seen so the resulting structure is as simple as possible. Gestalt laws of perceptual organization can work in combination to create an optical illusion.

Sensory perception and the brain

Sensory perception is not always an accurate representation of the stimulus. This can be limited by: sensory detecting abilities (sensory receptors). Conflicts with bottom-up and top-down processing. How many colors do you see? <20 dichromat (2 color receptors), 20-32 trichromat (3 color receptors), 33-39 tetrachromat (4 color receptors)

Summary of Gestalt Laws & Optical Illusions

The six gestalt laws of perceptual organization are a collection of principles (or laws) that attempt explain how we perceive objects. The gestalt laws can be used to describe how these optical illusions are created. Both top-down and bottom-up processing can influence our perception.