Thursday, April 30, 2020

Outline of Pavlov's lectures on Conditioned Reflexes 1927

What follows is my outline for Pavlov's Lectures Conditioned Reflexes (1927). Bracketed numbers refer to page numbers according Anrep's translation as found in the Classics in the History of Psychology page. The rest are my sparce notes. Had this properly indented to highlight theme hierarchy, but Blogger apparently refuses to comply. I hope for someone, somewhere it shows. I'll add Lectures XVI & XVII in a few days.

Lecture I

Recent physiological investigations
Investigative options
Through (then actual) psychology
Brand-new path of physiology stemming by the reflex as described by Descartes
A necessary reaction to an external stimulus through a definite nervous path
Objective and experimental
Pavlov's own frustrations in subjective methods
25 years of investigations and systematization (at the time of the lectures) with collaborators
Description of reflexes in general
These are for the survival of the organism (through adaptability)
Inhibitory and excitatory
Chains of reflexes
Identification of reflexes [12]
Example of freedom reflex
Investigatory reflex
Dynamic balance of reflexes in the organism

Lecture II

Choice of secretory reflex
Isolation from other stimuli [20]
Defense of isolation

Demonstration #1 [22]
Plain vanilla with metronome

Demonstration #2 [22]
Conditioned reflex. Signalization through sight . Food, conditioned itself

Demonstration #3 [23]
Food as an unconditional stimulus

Nomenclature of unconditioned and conditioned reflexes
Conditioning as learning

Conditions for successful conditioning [26, 392]
  1. It must overlap in time with the unconditioned stimulus;
The conditioned stimulus has to have some lead time;
The reverse doesn't generate a bond
  1. The organism has to be alert;
And free from any other nervous activity (as that arising from competing stimuli)
  1. A good state of health;
  2. The stimulus has to be mild or not overbearing.

Transformation of an unconditioned reflex into a conditioned one

Threshold of stimulus intensity

Lecture III

Second order conditioning
Third order conditioning found to be impossible

Conditioning through rituals [35]
Demonstration #4 [36]
Speculation on nervous connections

Characteristics of stimuli
Inpidual fluctuations in internal or external environment of the organism may, singly or collectively, acquire the properties of a conditioned stimulus
Trace conditioned reflex
Time lapse

Inhibition [43]
Description of external stimuli disrupting the conditioning of the dog [44]
Lasting effects
Old, established reflexes are more difficult to inhibit
Strength or unusualness of the stimulus has a proportional effect [46] !?
However, if not reinforced, they eventually lose their inhibitory powers !? Hence, they may be termed temporary inhibitory stimuli
Permanent external inhibition

Lecture IV

Internal inhibition
Develops progressively, often with difficulty, as opposed to external inhibition

Extinction (primary)
Weakening of the conditioned reflex by repeated application of the conditioned stimulus without reinforcement
Demonstration #5a
Fluctuations in the curve of extinction
External influences
Rate of extinction [51]
Peculiarities of each organism
Strength of previous conditioning
Number of trials
Intensity of the unconditioned reflex
Length of pause between successive repetitions
Secondary extinction
When primary extinction is happeningother conditioned reflexes are also affected notwithstanding if these are:
Homogeneous conditioned reflexes
Based on the same unconditioned reflex
Heterogeneous conditioned reflexes
On a different unconditioned reflex
After several extinctions even the unconditioned reflex might weaken [54]
The permanency of the secondary reflex also depends on
Its own reinforcement and extinction
If it's weaker than the primary reflex acted upon
When the stimulus is compound, the inpidual stimuli also suffer from secondary extinction
Similarly, the stronger the stimulus, the more effect it will have on the weaker and viceversa
Extinction beyond zero [58]
Measured by its effects on the secondary reflex
Spontaneous recovery
Demonstration #5b
Recovery by a few pairings
Extinction is regarded (by Pavlov) as a special case of inhibition and thus it cannot be completely destroyed. (Hence, nervous connections are rendered latent and subject to reestablishment)

Deviations in the curve of extinction

Temporary restoration of the condition reflects is regarded as a dis-inhibition [66] or inhibition of a inhibition

Lecture V

Internal inhibition (continued)
Combinations of stimuli
Conditioned inhibition/differential inhibition
An unreinforced combination will render an otherwise positive stimulus inactive
Temporal considerations
Overlap of a few seconds in the stimuli is of the essence for inhibition
A clear temporal separation of the stimuli renders the additional one as positive (of the second order) rather than inhibitory (provided it is not very intense, in which case it would work as an external inhibition)
Curve behavior [72]
Other factors
Character of the inpidual
Intensity of the stimulus
First establishment of an inhibitory process or a succeeding one
Summation or repetition of an inhibitory process [79]
Shortening of its effects
Dis-inhibition [82]
By the introduction of just another external stimuli the inhibition is partially lifted

Lecture VI

Internal inhibition (continued)
Interval between stimulus and reinforcement of the unconditioned reflex
By retarding a simultaneous reflex gradually
By jumping from a simultaneous reflects to a delayed one
There's an initial disappearance of the reflex, however, it gradually strengthens with enough trials and moves into intermediate position between the stimulus and the reinforcement
It is difficult to establish a delayed reflex without a previous application of a simultaneous regime
Intervening factors
Character of the inpidual
Type of conditioned stimulus used [90]
Trials during the preliminary stage
Whether the stimulus is continued or intermittent
Nature of the delay inhibition
Initially strong and not a gradual summation of the excitatory processes nor fatigue
Other stimuli acting on the delay phase
These may disrupt or not the inhibition depending on their type (strength)[94] or their repetition [98]
Initial excitatory behavior versus posterior inhibitory in the delay phase from one stimulus [103]
A compound stimulus is formed with the lapse of time experienced
Latent period
Brief recapitulation [106]
Experimental extinction
Conditioned inhibition
Inhibition of delay

Second order inhibition

Lecture VII

Reflex mechanisms
Analyzing mechanism
By which it selects out of the whole complexity of the environment those units which are of significance
Synthesizing mechanism
By which inpidual units can be integrated into an excitatory complex

Previous investigations of the analyzing mechanism
The superiority of the scope of the conditioned reflex
Initially, all the characteristics of the environment serve as a generalized stimulus and after some trials, the relevant stimulus from it come to the foreground, while those that are not, fall back [115]
Not based on dis-inhibition
Establishment of differentiations
Through repeated reinforcement
Not as effective if at all
By contrast [118, 122]
First, establish a reflex;
Present a similar, though contrasting in some aspect, stimuli without reinforcement;
Work from there to even finer contrasts

The non-reinforced stimuli lose their excitatory processes through inhibition […, 125]
Though not without fluctuations [120]
Can work with either positive or negative conditioned stimuli
Differential inhibition is the fourth type of internal inhibition
Intensity of the stimulus
Intensity of the unconditioned reflex

Lecture VIII

Instrumentation recap

Sense (analyzers) sensibility
Auditory [134]
Tone, pitch, rhythm
Instrument limits
Tactile [137]
Nutritive substances
Rejectable substances
Synthesis [141]
Compound stimuli
Overshadowing of different stimuli in type
Cutaneous is stronger than auditory; stronger than auditory; stronger than visual
Nevertheless, the weaker stimulus is necessary for the production of the conditioned reflects a when it has been compounded with a stronger one. Also on the weaker element can bring down a compound stimulus if it is not singly reinforced (inhibition).
If single stimuli already have served on conditioning, there is no overshadowing when compounded [IX]
Successive stimuli [145]
With same or different analyzers
Modifications of patterns
A set pattern can be differentiated from unreinforced ones although this, takes time
Inpidual stimuli lose their excitatory properties
Elementary and higher forms of analysis and synthesis [148]
Sense limits

Lecture IX

Irradiation and concentration
Internal inhibition initiated in a single definite point of an analyzer, rapidly irradiates over the whole analyzer, after which it is slowly concentrated upon its initial point. This can be traced.

Supposition that there is a correspondence between the analyzers and that of the cortex in regards of neighboring areas [154, 214]

Investigation of the nature of the phenomena [156]
Places of secondary and primary extinction

Auditory specific

Lecture X

Secondary inhibition of the other analyzers
Inhibition initiated in one analyzer reveals itself in other analyzers as well in the form of inhibitory aftereffect
Dependent on inhibition strength
Nonetheless the effect is weaker than in the primary analyzer
Experimental methodology [171]
Difficulties [175]

Aftereffects of the excitatory processes

Generalization of any recently established conditioned stimulus [185]

Lecture XI

Mutual induction

Positive induction
Inhibition leading to increased excitation
Following the extinction in some other area of stimulus within the analyzer
Not the form of dis-inhibition [190]
Depends on
The intensity of inhibition
Coarseness (or just how fine) of differentiation [194]
Coarser differentiation loses its induction when followed by finer training
Represents a temporary, phasic phenomenon in the establishment of inhibition
There are exceptions
Negative induction [196]
Excitation leading to increased inhibition
Difficulties in its investigation

Lecture XII

Interaction of irradiation and concentration with induction
These processes interact with one another
Sensitivity [208]
Of single non-reinforcement
Small influences over extended periods
Undulation (waves) in time and distribution of inhibition
Correspondence [214]

Positive induction applied to a definite place limits the spread of the inhibitory process

The interaction between expectation and mediation is determined either by the face of establishing new relations in the cortex or by the type of nervous system in different animals

Lecture XIII

The cortex as a mosaic of functions
Some cells respond to excitation while others to inhibition in a localized manner
Suggested problems (unresolved)
Functional demarcation
Its mechanism
Variability and stability [227]
Dynamic system [232]

Lecture XIV

Second kind of inhibition: inhibition in the cortex
Under the influence of conditioned stimuli that cortex sooner or later (sometimes very slowly) develops inhibition. This happens in a progressive manner
Frequent repetitions accelerates this process [237, 242]
This is attributed to the sensibility of the cortical elements which become functionally exhausted [244]
In other words, it is a protective mechanism
Shortening of the reinforcement delay
Avoiding many repetitions in one session
Interruption of the trials
Increase in the strength of the conditioned stimulus
Increase of the number of the conditioned stimuli (positive induction)
Increasing the strength of the unconditioned stimulus

When the inhibition has taken hold even the conditioned stimulus fails
A new conditioned stimulus restores the subject [239-241]

Lecture XV

A general spreading of this inhibition is possible: sleep or internal inhibition

Development of inhibitions
Prolonged action of a conditioned stimulus
Perhaps even more so with extinction
In differentiation it is clearer
Happens also with delayed reflexes

Starts with drowsiness and develops into deep sleep
The unconditioned stimulus even loses efficacy
With non-reinforcement
Reinforcement delays the progression of the secondary inhibition

Powerful stimuli (such as electric shocks) can also be found to develop internal and secondary inhibition

Some analyzers (senses) lend themselves more readily to inhibitions than others

Internal inhibition is explained as a scattered sleep [253] and functional fatigue [259]

Avoidance tactics [254]
The addition of other stimuli [255]
Even add to the sleep [258]
Monotonous stimuli on humans

Surgical investigations [259]

From sleep to inhibition [260]
With delays
Summation of inhibitions (cf. 256)

Excitation preceding drowsiness [263]

Final considerations

Lecture XVI

Transitional stages into sleep
Partial; localized sleep
Alert posture but unresponsive
Complete inhibition in the cortex; motor centers still free from inhibition
Subject's previous conditioning history
Numerous applications
Nature of the neutral stimuli
Weak and/or prolonged
Strong and short
May cause the spread of partial division into other areas of the cortex: "animal hypnotism" [269,312]
Variation of intensity in compound stimuli as a means of comparing them [269]
What can happen over many days (pathological) can be replicated in a few minutes in the transition to sleep
Paradoxical phase [271]
Strong stimuli do not have an effect while weak ones have a disproportionate one
Equalization phase
All the stimuli become equal in their effect
Intermediate (unnamed) phase
Medium strength stimuli have the greater effect
Return to normal

Relation to induction [276]

Narcotics [278]
Other transition controls [280]

No definite order in the phases can be established

Lecture XVII

Pathological disturbances arising from function

Dependence on types
Equal influences do not have the same effects […, 299]

Vivacious, but most likely to fall into drowsiness in the absence of stimuli. Predisposition to excitation […, 293]
Fraidy, but more apt to yield regular results under conditioning.  Predisposition to inhibition (Cf. Introverts).
Intermediate types [288]

Conflict between excitation and inhibition [292]

There is a breakdown of conditioned reflexes [290, ]. Acute neurosis

Rest [290,]
Stepping back and starting afresh [291, 319]
Chemical compounds [299]
Companionship [296]
Other stimuli [318]

Lecture XVIII

Transition from inhibition to excitation
Possibilities [311]
From a single point to the whole cortex
As injurious agent upon the cortex

Congenital weaknesses [312]
Definite conditions bring forth abnormalities
Types of stimuli according to intensity
The case of Petrograd 1924
Unusually strong stimulus
Breakdown of conditioned reflexes
Their restoration. Neurotic sequels (PTSD?)
Constitutions predisposed to inhibition become even more susceptible to it. Chronic pathological state [, 397]

Lecture XIX

Physical disturbances or interventions
Methodology and difficulties
Experimenter reflexes are the most likely to disappear well inherent, natural, reflexes are the first to resurface
Usually the greater the lesion, the greater it takes to recover
Recovered reflexes are often stronger [324] while inhibitions weaker
Complications [325]
Peculiar symptoms
Extirpation the whole cortex [328]
Simple reflex machine. Unconditionable
Acoustic analyzer centers [330]

Lecture XX

Visual analyser
Tactile analyser
Motor analyser

Lecture XXI

Activity after lesions
Example of reestablishment of conditioned reflexes [374]

Lecture XXII

Investigatory viewpoints
The one taken: the laws governing a complex system founded on the processes of excitation and inhibition
Determination and tabulation of different phases of the cortical activity
Absence or presence of inhibition or excitation
Their conditions
Their interrelations

Difficulties encountered [378]
Exquisiteness and complexity of the system
Reassessment of the old points of view
Secondary conditions [383]
Stimuli intensity

Way forward
Reducing the mass of various separate observations to terms of a progressive diminishing number of general more fundamental units [387]

Mechanism of dis-inhibition [390]
Necessary elements of conditioning

Lecture XXIII

Results in application to man
Habits identified as a chain of conditioned reflexes
Graduality in acquisition
Interruptions as disruptions of performance
Other similarities
Monotonous stimuli inducing drowsiness
Alertness and sleep
Pathological cases
Nervous and psychic disturbances
Violent changes in life, powerful stimuli…
(Petrograd 1924)
Cortex injury
Some inpiduals remain unaffected [397]
Identification with neurasthenia and hysteria [398]
Sleep disorders
Therapeutic measures [401]
Borderline states [404]
Hypnotic states
The conscious and the unconscious [410]
Final words
Much to explore and to systematize there still is


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