Midterm 1 Flashcards
Wilhelm Wundt
Start of experimental Psychology.
Separation of psychology from philosophy.
Measures reaction times and word associations.
Procedures to describe sensations
John Watson
Behaviorist Manifesto
Behaviorism
Replaces subjective introspection with objective observation of behaviours.
People were thought of as “responders” responding to conditioning through experiences.
Learning occurs as a result of the consequences of behaviour.
Behaviourists do not believe in mental phenomenas like knowledge, thinking, intention,…
Tolman: Cognitive maps
Organisms take in information from their environment and build up cognitive maps as they learn (latent learning)
Latent Learning
Tolman.
Experiment with 3 groups of rats in a maze, no reinforcement, regular reinforcement everyday, reinforcement only after day 11.
Group 1 doesn’t learn anything.
Group 2 shows steady improvement.
Group 3 shows sudden improvement on day 11, they learnt things in the first 10 days but only started using the knowledge once reward arrived.
The cognitive maps are inferred from the rat’s behaviours as they cannot be directly observed.
Minsky
Believed that you need systems of hierarchy to represent the world.
Computer program that would be able to use terms of relations such as inside, to the left,…
The most important thing is the idea of representation.
Skinner’s verbal behaviour
A behaviourist explanation of language development.
Language is a way to get other individuals to do something. All other functions (logic, communication) are only derivatives.
Should only think of language behaviours as the measurable effects they ave on human interaction
Noam Chomsky
Negative review of Skinner’s “Verbal Behaviour”
He argues language cannot only be learnt through reinforcement, there must some innate structure because children are not exposed to every single possible combinations of words by the time they can speak (poverty of the stimulus)
Poverty of the stimulus
Children are able to produce an infinite number of sentence even though they only heard a finite amount of them until now
Constraints and principles cannot be learnt
children do not “know” anything about grammar or syntax but still they can produce grammatical sentences
Chomsky’s LAD
Children are born with a Language Acquisition Device.
Unconscious process inside the child’s mind.
This is how children produce sentences they have never heard before (ie no eat cake/he hitted).
Criticism: It’s a black box how do we know how it works? Languages of the world are so diverse that such universality is rare. Only addresses syntax and not semantics (meaning of words)
Bottom-Up processing
Starts with sensory data (distal stimulus) and builds up representation.
STIMULUS -> ATTENTION -> PERCEPTION -> THOUGHT PROCESS -> DECISION -> RESPONSE
ie the letter A is a black blotch broken down into features by the brain and then perceived as the letter A
Top-down Processing
Starts with the expectations and contexts to help interpret incoming data.
Key difference: Later stages of processing affect earlier stages (ie PERCEPTION affects ATTENTION, and THROUGH PROCESS affects PERCEPTION)
Top-Down 3D perception
We use light sources to infer depth.
Single Light Source Assumption: our visual system’ interpretation is constrained by the rule that there can only be one light source. We also have a built-in assumption that light is coming from above.
Parallel vs Serial Processing
There is a big speed advantage in parallel.
In serial processing, the mind can only deal with one piece of information at a time, therefore when a lot of information is received, a bottleneck forms and slows down decision making.
Sternberg Paradigm
Give subjects a short list of letters to memorize. Have to quickly decide if an item is new or part of the list.
Serial process: items are tested one at a time, predicts a linear increase in response time as set size increases
Parallel process: items tested simultaneously, time would not increase as set size increases according to Sternberg.
Results: reaction time is linear, therefore concluded people think in a serial manner
Double-Stimulation Paradigm
You receive a first input X and are still processing it when you receive a second one Y. You can’t deal with Y until you are done with X. The separation between the onsets of the two stimuli is called SOA (stimulus-onset asynchrony).
As SOA increases, the reaction time for Y decreases because you have more time process. This is known as PRP (psychological refractory period), where you need this refractory period to clear out X.
Parallel and Interactive processing
Perception of visual event affected by perception of auditory events (ie hearing 2 beeps when a circle flashes once makes you think it flashed twice)
McGurk effect
Lip movement says “ga”, speech sound says “ba” and we perceive “da” which is a mixture of both
Identifiability
The ability to specify the correct combination of representations and processes used to accomplish a task
Marr’s approach to how the mind performs information processing
Different explanatory tasks at different levels:
- Computational level (WHY, goals): identify the specific information-processing problem that the system is configured to solve, and identify general constraints to solutions to that problem
- Algorithmic level (WHAT): explains how the system actually performs the task (identify inputs/outputs, algorithm for transforming input to output, specifies how information is represented). Also known as information processing level.
- Physical Implementation level (WHERE, HOW): physical realization of the system, identify neural structures realizing the basic representational states to which the algorithm applies, identify neural mechanisms that transform those representational states according to the algorithm
A complete understanding at one level may not be enough to fully explain an information processor of interest.
Calculator example
Physical Implementation level: explain the physical operations through transistors, resistors ect… -> you now know the physical processes but you don’t know what it is actually doing
Computational level: specify the laws of arithmetic and how the calculator conforms to these abstract laws -> you are missing how it is doing it at the most basic level
Algorithmic level: explain the information processing steps carried out by the addition algorithm
Marr’s Analysis of visual system
Identified two key jobs for the visual system:
- provide a 3D representation of the visual environment
- provide object-centered rather than viewer-centered frame of reference.
Computational level: input is light arriving in the retina, output is a 3D representation of environment. Goal is to infer surface boundaries from 2D image.
Algorithmic analysis: compute zero crossings over image
Physical Implementation: wiring P, Q and AND cells in early visual cortex
Marr’s stages of visual processing
IMAGE BASED PROCESSING (some pattern of light, pixels) -> SURFACE BASED PROCESSING (differentiate surfaces) -> OBJECT BASED PROCESSING (recognize object) -> CATEGORY BASED PROCESSING (what category it fits in)