Cognitive🔢 Flashcards
Cognitive machine challenge
Build a machine that reasons with logic: create new logic from facts already known (inferences)
Use symbolic logic (replace all words with symbols so machine can make inference automatically)
Existing logical computers
Blocks and chess
Blocks 1970s- Computer solves spatial arrangements by starting with known facts and infers how to arrange
Chess 1990s- start with known facts of chess positions, generate new positions and consequences of moves, choose best outcome
Learning with neural networks
Strengthen connections
Before- U to R
After-CS strengthened connections to U
3 types of Cognitive psychology models
Data analysis model- data driven and descriptive (line graph)
Box and arrow model- information processing, conceptual. IMPLICIT assumption
Computational model-informational processing as simulation, various levels of abstraction. EXPLICIT assumption
Performs cognitive tasks to learn how it is implemented in the brain, without neurobiology
Explicit vs implicit models
Cognitive process- implicit models
Computational models can make assumptions explicit and assumptions can then be tested (specific predictions for outcomes)
Goals of modelling
Must be specific, models are often implicit
Can test assumptions
Predicts outcome, help to select which experiment to perform and distinguish between models
Can be exploratory (not predictive) trends difficult to show from the brain (oversimplified however)
Abstraction and idealised real concepts
All models wrong but some are useful but explanation does not imply prediction
Marr’s 3 levels of understanding
How to think about info processing systems like the brain
Computation-WHY (problem) the goal e.g. recognise objects
Algorithm- WHAT (rules) represented approach, how carried out e.g. detect edges, outline
Implementation-HOW (solved physically) e.g. visual neurons sensitive to lines
Bottom up approach
Implementation (neural circuits)
Algorithm (how generate algorithms)
Computation (what can we solve this with)
Neuroscience favours this
Top down approach
Computational (specific problem)
Algorithm (to solve problem)
Implementation (how these representations can be implemented in neural circuits)
Experimental techniques favour this method (epistemological bias)
Marr’s level favoured by neuroscience
Implementation (has epistemological bias towards it)
Bottom up
Moravec’s paradox
Computers can do hard tasks to us e.g. solving tasks but not easy tasks to us e.g. perception
Multisensory integration and touch/movement study
Seeing and feeling that you touch the object is important
Anaesthetise finger to block all touch sensations (does not affect motor abilities)
Much slower and less precise to pick up objects, need to integrate
Reference frames
(representational schemas) represent different info from senses, transform representations to common representation
Need to know body orientation and position of object, relative positions(body schema) to external space to unify frames
Reference frames of the senses
Vision- eye centred/retinal, location of stimulus on retina
Audition- head centred, location of sound with respect to ears
Touch-body centred, location of tactile stimulus on skin
Need to convert between reference frames and to external space (the world, irrespective of location and orientation of body)
Reference frames and snake game
Need to know information about snake’s body layout to convert from player perspective to snake perspective
See space in top down view as player, but could control actions of snake in different view (first person)
Reference point
Reference frames need to be in same reference point
‘Is the object I’m seeing the same object I’m touching’
Transformations needed for us to convert between reference frames
Eye to head transformations- orientation of eyes needed
Head to body transformations- orientation of head needed
Body schema
Position of body in space, relative position of body parts
7 body schema factors
Spatially coded- body parts in external and relative space
Adaptive-changes over lifetime
Modular- body parts processed in different brain regions
Interpersonal- others movements make sense to you
Supramodal-combines input from proprioception, senses
Coherent- Keeps continuity so don’t feel disembodied
Updated with movement- continually tracks posture
Body image
Body percept (‘feel’ you have a body) Body concept (of what a general body look like) Body affect (how we feel about our body)
Structural description- hand attached to arm
Body semantics- names for body parts
Does body posture affect perception?
Temporal order judgement tasks
Participant stretches fingers on hand they think was stimulated first
Crossed arm condition-
worse at body perception, body schema INTERFERES with perception, confused about where touched
How does body schema develop?
Experiment-temporal order judgement task
4 month olds no difference if feet are crossed or not, no body schema interference BUT
6 month olds reach to incorrect foot half the time when crossed, Body schema/ posture now matters for perception. Interferes with tactile orientation
Cross modal contingency- tactile discrimination task
Determine which finger was vibrated:
Visual light distractors on same finger that was vibrated OR other finger
Delay= incongruent reaction time - congruent reaction time
Longer delays when distractors on same hand vs different hand
Touch and vision, two reference frames are converted between
Cross modal contingency task with crossed arms
Tactile stimulus on same side of body, visual stimulus on different side of body
Effect of visual distractor (delays) moved with hand when arm crossed as it switches visual hemispheres.
Cross modal interactions mediated by body schema