Cognitive Psychology Final

mind-body dualism

Reduce thought to computation Approach cognitive psychology using a computer metaphor.

Degraded Stimulus

influences perception stage only longer RT; slope the same;

SELF-TERMINATING SEARCH

Search stops when item found "present" half as steep as "absent" (bottom)

Receptive fields

"care about" size & shape Receptive fields overlap. Across a collection of receptive fields, orientation matters. cells in the cortex (brain) They have receptive fields too Record from 3 cortical cells Some prefer vertical, others prefer horizontal or oblique: -I/ SIMPLE CELLS maximal response to stimuli of a particular orientation ±15°. Lower visual processing includes ganglion cells, and simple cells which detect edges and lines with particular orientations

Turning Reductionism

"mental states are the computational states of a Turing machine" The mind is some type of Turing machine Beginnings of artificial intelligence

Formalism/Formal System

A finite set of parts/pieces + A finite set of rules -> Proper/logical sequences Example: Chess Finite pieces Finite Space Finite rules about movement, capture Complicated, but deterministic sequences of outcomes

Allen Turing

Turing Machine Symbol manipulating system capable of any mathematical operation

Token Physicalism

Any kind of matter than can support mental states can be a Turing Machine Carbon is not a privileged substrate "It doesn't matter what the matter is"

Questions about formal systems:

Are they COMPLETE? Are they CONSISTENT? Are they DECIDABLE/DEFINITE?

resting potential of a neuron

Characterization of axon with respect to electrical voltage inside vs. outside is negative "-"

Descartes Dualism: Body

Behavior of physical body can be explained mechanically. Involuntary actions Rudimentary notion of reflexes (automatic responses)

The all-or-none law states that:

Cell fires or it doesn't: longer/stronger stimulation does not influence individual action potentials

How do the relations between changes in the stimulus & behavior inform us about the Mind?

Donders: Simple vs. Choice Reaction Time (RT) Stage Theory: thought = train of processes or stages. RT is the sum of all different processing times. Subtraction Method: RT2 - RT1 = Stage B processing time. Assumption of Pure Insertion: change from Task1 to Task2 inserts a new stage without altering others

Energy -> Brain

E -> S: Physical (F) energy converted to Psychological (Y) response In some sense, S copies E, however imperfectly. It is the 1st stage in getting the world inside the mind.

EXHAUSTIVE SEARCH

Every item in STM is always examined absent/present same slope (top) RT increases w/ set size slope = item search time

How do we study to mind? Behavioral Approach (not Behaviorism)

Information Processing (IP): abstract description of how information is manipulated—flow diagrams IP->sequence from input-to-output Infer components of the mind based on behavioral measures

Descartes' Nativism

Knowledge is inherited

Paradox of Learning/Knowledge

Knowledge is necessary to acquire Knowledge

Descartes Mind-Body Dualism

Mind and body are distinct entities

Type Physicalism

Mind and mental states REQUIRE carbon based matter The Turing reductionism and Token physicalism allow us to model the mind and body as Descartes envisioned Mind as a symbol manipulating machine INDEPENDENT of the particular physical characteristics of the body

How do we study to mind? Physiological Approach (neuroscience)

Neurological correlates of behavior Links between brain structure & cognitive function Infer component of mind based on physiological changes

Sternberg's Model as prototype of Information Processing Theory

No attempting to attribute information processing to any brain location or brain process Highly symbolic - no consideration of neural representation Computer metaphor-high speed scanning Assumption of additive finishing times Independent/serially ordered processing stages RT is the sum of all different processing times

Descartes Dualism: Mind

Non-physical mind provides humans with consciousness, free will, and awareness. Voluntary actions Can modify, facilitate or restrict involuntary actions

TEMPORAL SUMMATION

One or more presynaptic neurons transmit impulses in rapid-fire order

PHYSIOLOGICAL APPROACH: How do the changes in the brain inform us about the Mind?

Patient HM (Henry Molaison): Bicycle accident age 9 Increasingly severe epileptic seizure since age 10, unresponsive to medication Bilateral HIPPOCAMPUS removal age 29 Short term memory is normal As long as attention is not diverted Most memories prior to operation (LTM) accessible Surgically removed brain areas are important for transferring information from short term memory to long term memory.

Descartes' Rationalism

Primacy of Reason "the ghost in the machine"

Godel

Provided 2 theorems: 1) For any CONSISTENT formal theory it is possible to construct an arithmetic statement that is true but not included in the theory. 2) If a formal system can be proven to be CONSISTENT and COMPLETE from within itself, then it is INCONSISTENT.

Russell/Hilbert

Said you can look at formal systems in the same way as scientists look at other things in nature. Through observation, classification, etc. Mathematics as the object of inquiry, not a tool of inquiry Developed predicate calculus: a language suited to asking scientific questions about mathematics

Stage 2: NEURAL PROCESSING

Separate receptors converge onto a ganglion cell pool information to ganglion cells some receptors excite; others inhibit ganglion cell ->collection receptors is ganglion's RECEPTIVE FIELD->Receptive fields "care about" size & shape

Godel's Theorem

State that it is impossible for a system to generate all possible truths

Aristotole

The actual world is real, and all knowledge can be extracted from it. Knowledge is accessible by examining actual world and reasoning about it. Knowledge is constructed by associating sensory information.

Reminiscence theory of knowledge

The immortal soul has complete Knowledge of the pure forms, this knowledge is only accessible through introspection.

SPATIAL SUMMATION

The sum of multiple synapses firing at different locations at one time to create a net effect.

Plato

True Knowledge can only be obtained through appreciation of the pure forms, because only they have real, permanent existence.

Principle of Neural Representation:

We (our minds) have only direct awareness of states of the body. The mind is not DIRECTLY aware of the states of the environment. Mind inters states of the environment from states of the body.

COMPLEX CELLS as feature detectors

a neuron in the visual cortex that responds best to moving bars with a particular orientation: - / response (to orientation & size & motion direction) maximal response to stimuli of a particular orientation, size AND motion

action potential

electrical "+" signal within the neuron Voltage difference changes Membrane destabilizes "+" charge travels down axon Signal is PROPAGATED from one end to another w/o losing strength.

Feature detectors

nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle, or movement

LATERAL INHIBITION-

neural circuitry/mechanism for detecting stimulus features by the convergence of inhibitory and excitatory signals. Feature detectors

Distributed coded representation

the mental representation is based on a "chorus" of neural activity

Stage 1 of Transduction

transforming one form of energy into another: Source->Sun reflected scattered absorbed surfaces, substances Some light gets to eye