Lecture 1- perception and cognition

Question 1

What are perception and cognition

Answer 1

Perception: senses and experience of environment
Cognition: thoughts, thinking and action on how we understand the environment

Together they are how we sense, understand and act upon our surroundings, dictating behaviour.

Question 2

Why do we study perception and cognition

Answer 2

Scientific curiosity, application and understand pathology and improve interventions (for sensory/ cognitive loss).

It is a cross disciplinary approach

Question 3

Tools and techniques we use to study cognition and perception

Answer 3

Behaviour: outcomes
Eye-tracking: what are they looking at and focusing on
Virtual reality
Neuroimaging: how cognition works.

Question 4

Information processing chain

Answer 4

Linking of perception to behaviour+thinking typically using cognitive disciplines (cog neuroscience etc)

1) Action/ thinking
2) Memory
3) Attention
4) Perception (sensation)
Either bottom up processing
OR
Top down: working in the opposite way where we use previous experiences to predict what the next event is. Because we predict it we attention until the sensation.

Question 5

Networks:

Answer 5

There is a distributed network of brain regions linked to cogntion and perception not specific areas for specific functions

Question 6

Paradigm of information processing

Answer 6

Framework or model which guides research including assumptions, concepts and methods to study a particular phenomenon.

Currently the Information processing paradigm

Central scientific approach: acquisition, processing, storage and recall of data in the brain

Question 7

2 ways of filtering information

Answer 7

1) Perceptual filter:
selectively attend to certain sensory inputs while ignoring others
2) Perceptual bottleneck:
limitation in the brain’s capacity to process all available sensory information at once.

Information must be collected efficiently: what is relevant, urgent and what can be ignored. This processing is effortless for us and we are very good at it.

Question 8

Perception limits

Answer 8

We have differing levels of perception and some may be able to realise things others don’t
Medical professors found to be more attentive

Question 9

Sensing magnetic fields

Answer 9

Humans use tools to exploit the magnetic field of the earth for navigation such as compasses.

Birds use magnetic fields for orientation without need for tools.

Question 10

What is Echolocation

Answer 10

Used by bats
Also by humans- using soundwaves to find location of objects

Question 11

Transfers across sensory modalities

Answer 11

help have detailed perception as areas substitute other weaker modalities

1) Ventriloquism: from puppet/ other source rather than speaker

2) Synaesthesia: mixing of senses

3) Sensory substitution: replacing missing sense with other e.g. vOICe translating video images into sounds

Question 12

Plasticity of the brain

Answer 12

This is the brain’s ability to reorganise itself by forming new neural connections in response to experience, learning or activity.

• Adaption due to sensory loss
• Rewiring through learning
• Recovery after injury
• Sensory substitution and technology

Question 13

4 theories of perception

Answer 13

Gestalt psychology
Direct perception (Gibson)
Constructivist approach
Information processing approach

Question 14

Gestalt psychology

Answer 14

Views perception as a whole

Principles of perception: proximity, similarity, symmetry, continuity (crossed over arms look like one), closure (filling in gaps to see whole shape), figure-ground (differentiating objects from background), common fate, Praegnanz (good shape)
We fill in gaps/ make assumptions based off these

Question 15

Direct perception (Gibson)

Answer 15

Perception is direct and does not require interpretation or internal representation because the environment provides all sensory information needed.

Bottom up processing: exploit richness of sensory information directly and there is no need for higher level cognitive processing

Comprehensive capture of information: the optic array provides complete and unambiguous information about the environment.

Unambiguous spatial layout: the motion of object relative to the observer provides direct spatial attention- flow field.

Object affordance: the environment provides actionable opportunities based on context
Resonance: perception involves tuning into relevant environmental information

Question 16

Constructivist approach

Answer 16

Perception is an active process not just sensory input as the brain constructs a meaningful interpretation of the world by combining sensory input with prior knowledge- Neisser and Gregory.

Active construction (top down processing) mind fills in gaps to resolve ambiguities and create a coherent percept.

Interactive comparison: input is compared with stored knowledge in a continuous feedback loop

Hypotheses and expectations: the brain generates predictions - hypotheses based on prior experiences which guide perceptions (illusions)
Modern extension of this theory is the Bayesian estimation

Question 17

Information processing approach

Answer 17

Perception is a step-wise process.
Likens perception to computer processing information. Gathers, processes, stores in memory and uses sensory input to generate action.

Neuroscientific + computational approaches views perception as such

Receptors gather input: transform stimuli to neural signals
Filter: encoding information efficiently
Receptive field: localisation and tuning
Illusions: misinterpretations of the physical world
Active sensing: intelligent search strategies/ actively seeking information to improve accuracy.