Edwin Ray Guthrie, The Psychology of Learning
(1935):
1. the environment is described as an uncountably vast
collection of micro-stimuli corresponding to every aspect of a total stimulus situation
that an animal could possibly attend to
2. the S-R connection attains its full
strength on the first
pairing of the stimulus and response: contiguity, not frequency!
3. a new response made in the presence
of a stimulus completely erases / obliterates / replaces / "writes
over" any previous response to that stimulus (recency, or "postremity"); an S-R
connection is otherwise permanent
interpretation of
concepts based strictly on mechanism - no stimuli have value for
the animal:
"reinforcement"
works not because the animal has some goal or desire but because it changes
the stimulus situation, thus protecting the successful response: no new
response can be attached to those stimuli if they're no longer present
- ex.: when a cat gets out of a puzzle box, it
no longer has the puzzle box stimuli to connect a new response to -- so for
those stimuli the response that got it out of the box is preserved; note: no value
in freedom (or in ANY reinforcement)!
- learning appears to be gradual because it
takes several trials for significant portions of the collection of
micro-stimuli to all have the correct response connected to them
"extinction"
is the result of failure to "protect" an established response:
without reinforcement (i.e., a change of stimulus situation to protect the
response), any new response can simply take the place of the old one
"punishment"
only works when it causes the animal to make a new response to a stimulus
stiuation
- ex.: a child running toward the road should
be slapped on its face (to cause a recoiling response), rather than on its
behind (which is a stimulus to propel it forward even faster, adding to the
undesirable response); an analogous experiment with rats was done by Fowler and
Miller (1963)
- ex.: a child throwing her coat on the floor
should be required to enter the house again, take off the coat again, and hang
it up; this new response to the front-door-stimuli will replace the
coat-throwing-response
[for the curious:
"motivation" simply provides a set of stimuli (e.g., stomach pangs
for hunger, dry lips for thirst) that stay with the animal until it
meets that need (e.g., by eating or drinking), after which they are no longer
present
- this causes the eating
or drinking response to be connected with those so-called "maintaining
stimuli" in the same manner as described above; note: no value
in food!]
important aspects transcending
the particulars of Guthrie's contiguity theory:
1. description of environment as
collection of micro-features (especially in modern connectionism)
2. notion of competing responses used
in explanation of extinction and punishment
Clark Hull, Principles of Behavior (1943):
·
SER = D x SHR - IR - SIR - SOR
SER reaction potential
_
SER effective reaction potential
·
SER momentary effective reaction potential
D = drive: motivation; generic energizer of behavior
SHR = habit strength: product of learning; permanent; from number and amount of reinf.
IR = reactive inhibition: fatigue; Pavlov's "internal inhibition" of a response
SIR = conditioned
inhibition: learned inhibition of a habit; IR connected to a
stimulus; this could be learned because NOT-responding is
itself a response that
reduces IR (fatigue) -- which is a kind of
drive to "not-respond"
SOR = oscillation effect: random
factor in prediction of behavior strength: the
fluctuation of the nervous system's threshold for responding
given a certain level
of "effective reaction potential"
A Behavior System
(1952):
·
SER = D x SHR x K x V - IR - SIR - SOR
SER reaction potential
SHR = habit strength: only from number of reinf. (not amount)
K = incentive motivation:
from amount of reinf.,so...
SER = reaction potential = (drive) x (habit strength) x
(incentive motivation)
[we're
ignoring V in the 1952 equation, but for the curious...
V
= stimulus-intensity
dynamism: intensity of external stimulus]
according to Hull all
learning, classical and instrumental, is due to reinforcement; but Spence and others accepted
contiguity too.
- originally, reinforcement = need
reduction
(biological: hunger, thirst, sex, sleep, warmth, pain avoidance, etc.), but...
- need reduction later changed to drive
reduction (or drive
stimulus reduction) -- perceptual or "psychological" vs.
biological; e.g., hungry rats can be reinforced by non-nutritive saccharine
water, dogs by "sham eating" in which food never reaches stomach
extinction due to build-up of IR ; spontaneous recovery happens after IR dissipates; when SIR equals SHR extinction is final
Crespi-Zeaman effect (Crespi, 1942; Zeaman, 1949) -
changing amount of reinforcement had unexpected sudden effect on
behavior: incentive motivation K must be separate factor in SER
hypothetico-deductive
system: postulates
-> theorems derived -> experiments as tests -> revision of postulates
as necessary