A. Reflexes (S -> R)

• Probability, Latency, Magnitude, Refractory Period
• Types/Examples
• Sherringtonian (Sensory Nerve, Interneruon, Motor Nerve -- e.g., knee jerk, pupil constriction, dilation)
• Complex Motor -- e.g., chewing, swallowing, gagging, vomit, -- walking, Moro Reflex, arm withdrawal.
• Glandular/Hormonal -- e.g., Salivation, Sweating, Aldosterone Release, Histamine Release ...
• Localized Capillary Responses -- e.g., Hives, Blisters
• Changes in Reflexes
• Dynamic changes of nonassociative learning
• Neuron/Brain Development and Neurogenesis
• Brain Plasticity...

• Long term change in reactivity
• versus Adaptation, short-term habituation, and fatigue
• Long term habituation
• Stimulus specific
• examples... Box 3.1, Box 3.2, LTD
• Sensitization
• Usually NOT Stimulus specific
• Usually NOT as long-term
• examples... Box 3.2, LTP
• Habituation/Sensitization in Simple Animals (e.g., Aplysia: Syphon touch, gill retraction, and Tail shock
• Complexities
• Intensity effects -- need not be linear.
• Large individual differences
• Post hoc Interpretations...  as bad as Mr. Freud!!
• Notice that the right balance of habituation and sensitization sets optimal awareness.
• Mrs. Coolidge shares a fact...  the infamous "Coolidge effect."

• Now, the 2 x 2 Association Matrix (Figure 3.1):
• 
  

a. CS AND US BOTH PRESENT	b. CS ALONE (HABITUATION CTL)
c. US ALONE (SENSITIZATION CTL)	d. NEITHER CS NOR US (CONTEXT)

• Association occurs when:
• Contiguity of CS and US  -- "CS and US Together"  (Correlated)
• Contingency between CS and US  -- "CS predicts US"  p(US|CS) > all other cells.
• Barker proposes a 2 stage theory -- Contiguity important at first, Contingency important eventually
• Example: Pavlov's Salivary Conditioning
• Dog in harness sitting comfortably, but with a tube for meat powder (US), a tube for saliva (UR, CR), and a bell (NS/CS).
• Repeated trials with Bell preceding Food.
• At first, the dog orients to the Bell, salivates to the Food.
• Ultimately, the dog salivates to the Bell, salivates to the Food.
• CS -> CR
• US -> UR
• The Learning Curve: Figure 3.4
• Other Examples:
• Aplysia: Maintained Gill Withdrawal (CR) to Syphon Touch (CS) if paired with tail shock (US) (Box 3.3)
• Honeybee proboscis extension (CR) to cinnamon oil (CS) associated with sugar water (US)
• Infant eye blink (CR) to tone (CS) paired with small puff of air to eye (US)
• Excitatory Conditioning (vs Inhibitory Conditioning, to be defined later)
• Appetitive (Generally, US is something the individual will approach and keep contact with)
• Defensive, Aversive (Generally, US is something the individual will escape or avoid)
• Parameters (Procedural characteristics that you can change yield the Four Tenets of Ass. Theory).
• Type of CS-US pair (some combinations condition easily, some with difficulty).  Barker indicates this Tenet as "Similarity"
• Intensity of CS/US (Rule: Within limits, the greater the magnitude the better the conditioning)
• CS-US interval (Rule: optimal conditioning when this interval is between 0.5 sec to 7 sec)
• Intertrial interval (Rule: optimal conditioning when this interval is greater than 5 minutes)
• Frequency (Rule: conditioning improves with continued training)
• Is it Conditioning? or is it a Nonassociative Change in Reactivity?
• Conditioning (Association) Group vs ... Nonassociative Groups
• Habituation control group (CS only) and then test with CS
• Sensitization control group (US only) and then test with CS
• Random control group (a = b = c) and then test with CS
• Extinction and Spontaneous Recovery and Rapid Reconditioning
• Presenting CS alone AFTER it has been trained as a CS leads to decline in CR
• Presenting CS and US Randomly after CS has been trained as a CS leads to decline in CR
• If Extinction is followed by a resting period and the extinction resumes, there is a return of CR for several trials (Spontaneous Recovery)
• If Extinction is followed by a return to Conditioning, CR returns much more rapidly than during the initial conditioning.
• External Inhibition and Internal Inhibition
• Defining Inhibition: active suppression of CR.
• External: a Disruptive stimulus occurs and  CR does not occur
• Internal: Pavlov proposed that Extinction produced an active suppression of CR.  This is one account of spontaneous recovery.  Occasionally a new stimulus can disinhibit the CR.
• Generalization and Discrimination
• Stimuli similar to the CS also produce a CR.
• The CR to these other stimuli may be of diminished strength (Gradient of Generalization)
• Generalization is Adaptive...
• Second Signal System.
• CS as first Signal  (sight of apple "stands for" the sweet/sour taste of apple.
• A Name as second Signal (name of apple "stand for" this sweet/sour taste too
• Why distinguish between First and Second Signals?  Because the name often stands for the sight of the object that in turn stands for "experience with" the object.
• This association between words and the experience of things is very powerful and is the basis of much of language.
• How the Nervous System accomplishes Associative Learning
• Remember the Aplysia.. We know which neurons change.  (Box 3.3)
• A peek inside Spotski. We can see which areas of the brain are involved. (Box 3.4)