Psych 140

• It is a relationship between a specific event and a simple response to

  that event.

  Reflex
• It is either present at birth or appears at predictable stages in development.

  Reflex
• When does reflex failure happen?

  consumed excessive amounts of alcohol or other drugs that depress the central nervous system.
• Charles Darwin


  1809, England, tried medicine and theology but stopped, then pursued natural history
• HMS Beagle voyage


  1. Purpose: map shorelines of land areas around the world

  2. Opportunity to explore different species of plants and animals to understand the origin of the species

  3. Brought the book "Principles of Geology" by Charles Lyell
• Charles Lyell


  Considered the "Father of Geology", argued the Earth had been around for million years and changed slowly, so there was no reason to think that vast variety of life forms appeared overnight in their current form
• Animal breeding


  Deliberate model of changes "intervention by breeder"
• Thomas Malthus


  Argued population =/= utopia, but population = ruins, because of limited resources < increase of population, "nature is the breeder"
• Darwin: 'Owing to this struggle for life, any variation, however slight and from whatever cause proceeding, if it be in any degree profitable to an individual of any species, will tend to the preservation of that individual, and will generally be inherited by its offspring. The offspring, also, will thus have a better chance of surviving.'
• Classical conditioning


  The process whereby we learn to predict when and what we might eat, when we are likely to face danger, and when we are likely to be safe. It is also integrally involved in the learning of new emotional reactions (e.g., fear or pleasure) to stimuli that have become associated with a significant event.
• Systematic studies of classical conditioning

  • Began with the work of the great Russian physiologist Pavlov
  • Also independently discovered by Edwin Twitmyer in a Ph.D. dissertation submitted to the University of Pennsylvania in 1902
• Psychic secretions


  Stomach secretions elicited by food-related stimuli, which seemed to be a response to the expectation or thought of food
• Vul'fson and Snarskii


  • First systematic studies of classical conditioning in Pavlov's laboratory, focusing on salivary responses to various substances placed in the mouth
• Orosensory stimuli


  Sensations of texture and taste in the mouth
• Object learning


  The association of one feature of an object with another
• Conditional stimulus (CS)


  The tone or light, whose effectiveness in eliciting salivation depended on pairing it several times with the presentation of food
• Unconditional stimulus (US)


  The food or sour taste, whose effectiveness in eliciting salivation did not depend on any prior training
• Conditional response (CR)


  The salivation that eventually came to be elicited by the CS
• Natural Selection


  Helps species adapt to change over generations, changes not just physical change but also certain kinds of behaviour as well, helps organisms adapt to change, not the individual
• Unconditional response (UR)


  The salivation that was always elicited by the US
• Classical conditioning has been investigated in a variety of situations and species
• Fear conditioning


  • A major focus of investigators of Pavlovian conditioning, involving the conditioning of emotional reactions
  • Shock is used because it can be regulated with great precision and its intensity can be adjusted to avoid any physical harm
  • Freezing is a common defense response that occurs in a variety of species in anticipation of aversive stimulation
• Lick-suppression procedure


  An indirect measure of fear-induced immobility, where the ongoing behavior of licking a drinking spout is suppressed when a fear CS is presented
• Lever press suppression


  Another indirect measure of fear-induced immobility, where rats suppress their lever pressing for food reward when a fear CS is presented
• Eyeblink conditioning


  • A prominent technique for translational research involving classical conditioning, using the eyeblink reflex as an early component of the startle response
• Sign tracking


  • Animals often approach and contact stimuli that signal the availability of food, which is dramatically illustrated when the signal is located far away from the food cup
  • Individual differences in sign tracking are correlated with individual differences in impulsivity and vulnerability to drug abuse
• Goal tracking


  Conditioned behavior that tracks the goal object, which is food
• Taste preference and aversion learning

  • A taste preference is learned if a flavor is paired with nutritional repletion or other positive, while a conditioned taste aversion is learned if ingestion of a novel flavor is followed by an aversive consequence
  • Taste aversions can be learned with just one pairing of the flavor and illness, and can occur even if the illness does not occur until several hours after exposure to the novel taste
• Evaluative conditioning


  Our evaluation or liking of a stimulus is changed by having that stimulus associated with something we already like or dislike
• Excitatory Pavlovian conditioning


  • Organisms learn a relation between a CS and US, such that presentation of the CS activates behavioral and neural activity related to the US in the absence of the actual presentation of that US
• Short-delayed conditioning


  The most frequently used procedure for Pavlovian conditioning, where the US is presented slightly after the start of the CS on each trial
• Trace conditioning


  Similar to short-delayed conditioning, but the US is not presented until some time after the CS has ended, leaving a gap between the CS and US
• Long-delayed conditioning


  Similar to short-delayed conditioning, but the US is presented after a longer delay from the start of the CS
• The laws of governing inheritance are quite unknown
• Interstimulus interval


  The time between the conditioned stimulus (CS) and the unconditioned stimulus (US) within a conditioning trial
• Short-delayed conditioning


  1. CS starts each trial

  2. US presented after a brief (less than 1 minute) delay

  3. CS may continue during the US or end when the US begins
• Trace conditioning


  1. CS presented first

  2. US not presented until some time after the CS has ended

  3. Gap between CS and US called the trace interval
• Long-delayed conditioning


  1. CS starts before the US

  2. US delayed much longer (5-10 minutes or more) than in short-delayed procedure

  3. No trace interval, CS lasts until US begins
• Simultaneous conditioning


  CS and US presented at the same time
• Backward conditioning


  US occurs shortly before, rather than after, the CS