Intro to Vision Science Terms Flashcards
Visual Illusions
misperceptions due to processing in visual system, result in a percept that differs from reality (NOT OPTICAL ILLUSIONS)
eg. apparent convergence of vertical lines - rising objects appear to fall outward at the top - connects to buildings with columns (parthenon used distorted building made them inclined inwards to compensate for visual illusion and make them appear parallel and straight
Sensation
simple sensory experience elicited by a stimulus; conversion of energy or chemicals to a neural code
eg. senses are vision, audition, gustation, touch, warmth, cold, pain
Information Processing
describes the behavior of a particular kind of device (info processor),
looking at mind as an info processor which is a complex system that receives, stores, retrieves, transforms and transmits information, done by processing info (data) according to rules/procedures (program).
3 accounts: implementational, formal, interpretational
Perception
conscious experience of objects; organization and interpretation of neural signals
eg. recognition or identification of an object based on sensations, using vision to identify the lightwaves/shapes that make up a phone as a phone
Implementational Aspects of Perception
how perceptual procedures are physically realized in the “wetware” of the brain, described in terms of physical structures involved, neurophysiology aspect
Formal Aspects of Perception
information processes are represented in symbols and abstract structures, described in terms of underlying functions and knowledge structures, rules are formal only depend on token type
Interpretational Aspects of Perception
a description of what a system is doing and why, in terms of the behaviors observed, what is the goal
Tri-Level Hypothesis
basic assumption is perception is information processing, 3 levels
1) Computational theory (behavioral level) - goal of computation, why appropriate, logic strategy by which it can be carried out, logic/mathematics.
2) representation/algorithm (functional level), how can theory be actualized, what is representation for input/output, what is algorithm for transformation psychophysics/computer simulation
3) Hardware implementation (physical level), how can representation and algorithm be realized physically, neuroscience/electrical engineering
Primitive Operations
makes up an info processing system, makes up the functional architecture, biologically fixed part of cognition,
eg. analogy is the dictionary from which all sentences in some language can be created
Functional Analysis
take a very complicated functional description and decompose it into organized description of simpler subfunctions, typically just leads to descriptions not to explanations
eg. Ryles Regress: colour perception -> processing of info in colour pathways -> neural circuits -> neuroanatomy -> neurobiochemistry -> chemistry -> physics -> ?
Subsumption Criterion
if a sub function can be explained using natural, causal laws (physiological laws) then decomposition can stop
eg. colour vision was described functionally in trichromatic theory but was not subsumed until three different photopigment molecules isolated in 1960s, there is no need to explain how / why molecules are photo sensitive
Cognitive Penetrability Criterion
if a perceptual phenomenon cannot be altered by a change in beliefs, then the function is cognitively impenetrable, if it is not changed by top-down processing then it implies it is bottom-up and thus must be handled by the functional architecture
eg. visual illusion like the simultaneous colour contrast, even if you know what colours actually are (same shade of red) it does not change the experience of the illusion (one red seeming more orangeish and the other red seeming darker)
Weakly Equivalent Models
from engineering perspective, just develop system that accomplishes some task not necessarily in the same way as humans (pure AI), system can pass a test of intelligence for wrong reasons from a psychological perspective. Same computation, different representation/algorithm, different implementation
eg. AI playing chess
Strongly Equivalent Models
from cognitive science perspective, want to develop models of human processes that exhibit the same behavior for the right reasons (same underlying fundamental processes being used). Same computation, same representation/algorithm, different implementation