Biological Influences on Learning

1. Biological Influences on Learning Chapter 9

2. General Laws Of Learning 2 • Learning is the main determinant of action • Laws of learning reveal themselves in any study of behavior, even if they are not behaviors exhibited in a natural setting. • Past experience do not interfere with the learning involving arbitrary stimuli in the laboratory. • Conducted in humans and non human animals. • The specific CS, US (Pavlovian), reinforcer, and response (Instrumental) is arbitrary. • Extreme Enviromentalist and Nuturist!!!!!

3. Watson and General Laws 3 • “The behaviorist, ……. recognizes no dividing line between man and brute. The behavior of man, with all of its refinement and complexity, forms only a part of the behaviorist's total scheme of investigation” • "Give me a dozen healthy infants, well-formed, and my own specified world to bring them up in and I'll guarantee to take any one at random and train him to become any type of specialist I might select—doctor, lawyer, artist, merchant-chief, and, yes, even beggarman and thief, regardless of his talents, penchants, tendencies, abilities, vocations, and race of his ancestors”

4. A Possible Rapprochement 4 Millions of Specific Laws One General Law Exaptations (serving one particular function, but later but modified to serve another)

5. Flying Dinosaurs and Exaptations 5 • Feathers for thermoregulation • Recycled for flight So, modes of learning should be conserved and modified for other purposes

6. Behavior Systems Approach 6 • Learning acts within innate behavior systems and functions to change the integration, tuning, instigation, or linkages. • According to Timberlake, an animal possesses instinctive behaviors such as feeding, mating, social bonding, care of young, and defense.

7. 7 • Learning improves simple and complex motor tasks through repetition. • Activation of a mode can also be conditioned to cues that signal the receipt of reinforcers. • Conditioning of a specific mode produces a general motivational state that sensitizes all of the perceptual-motor modules in that mode. • Different stimuli can be conditioned to different modes. • Variations of learning can occur between species.

8. Constraints and Predispositions 8 • Constraints • When learning occurs less rapidly or less completely than expected. • Predispositions • Instances where learning occurs more rapidly or in a different form than expected.

9. Constraints: Animal Misbehavior 9 • Breland & Breland (1961) initiated the use of instrumental procedures to teach exotic behaviors to animals. • Animals learned the behaviors, but began showing instinctive behaviors. • Instinctive drift • When instrumental behavior deteriorates despite continued reinforcement due to the elicitation of instinctive behaviors.

10. IQ Zoo • Animal misbehavior may also be a result of Pavlovian conditioning. • For misbehavior to develop, stimuli resembling the natural cues must be consistently paired with the reinforcer and must reinforce naturally occurring species-typical behavior.

11. Constraints: Schedule-Induced Behavior 11 • Skinner (1948) found that reinforcing pigeons on an FI-15 sec. schedule resulted in stereotyped behavior. • Superstitious behavior • Skinner thought the “ritualistic” stereotyped pattern of behavior may have associated superstitious behavior with reinforcement. • Alternative view is the ritualistic behavior fill the “behavioral vacuum” between rewards

12. 12 • Terminal behavior • The behavior that precedes reinforcement when an animal is reinforced on an interval schedule of reinforcement. • Interim behavior • The behavior following reinforcement when an animal is reinforced on an interval schedule of reinforcement. • Schedule-induced behavior • The high levels of instinctive behavior that occur following reinforcement on an interval schedule.

13. Schedule-Induced Polydipsia (SIP) 13 • The high levels of water consumption following food reinforcement on an interval schedule. • Some important aspect of food can produce excessive drinking. • Has been observed in rats, pigeons, and nonhuman primates. • Usually occurs in the immediate time following reinforcement and decreases as time for the next reinforcement nears.

14. SIP Group Control Group

15. The Nature of Schedule-Induced Behavior 15 • Riley and Wetherington (1989) proposed that schedule-induced instinctive behavior is a product of periodic reinforcement. • The relative insensitivity of water-induced polydipsia to taste aversion is compelling evidence of this.

16. Does Schedule-Induced Behavior Occur in Humans? 16 • Gilbert (1974) suggested that interval schedules could be responsible for some peoples’ excessive alcohol consumption. • Rats on interval schedules show excessive consumption of ethanol; cocaine solution.

17. Arm-Chair Quarterback Blitzed 17 Stay Budweiser Sipping Go Inter-Potato Chip Interval

18. 18 • Schedule-induced polydipsia in animals is a good model for excessive alcohol consumption in humans. • Smoking and eating are other type of schedule-induced behaviors seen in humans. • Evidence is weaker in humans, and natural schedule induced behavior develops more slowly in humans than in animals.

19. Schedule-Induced “Chin Rubs” 19

20. Scheduled-Induced Anorexia 20 • Rats fed once per day at the same time • Periodic 24 hour schedule • Free-access to wheel (or not)

21. Activity-Induced Anorexia 21

22. Predispositions and Taste Aversion 22 • Preparedness? • Avoidance of a flavor that precedes an illness experience (implies selectivity) • Long-delay learning? • The association of a flavor with an illness that occurred even several hours after the flavor was consumed. Is this a special type of learning

23. The Selectivity of Flavor Aversion Learning 23 • Garcia and Koelling (1966) demonstrated this phenomenon in a groundbreaking study with rats. • Seligman (1970): rats possess an evolutionary preparedness for flavor aversion learning. • Rats can also associate an environmental cue with illness. • Taste cues, however, are especially salient.

24. 24 • Birds acquire visual aversions more readily than taste aversions. • Rely more heavily on visual system for food. • Search for food during the day. • Rats are nocturnal, and rely more heavily on gustatory information to find food.

25. Long-delay learning? 25 • Concurrent interference • The prevention of learning when a stimulus intervenes between the conditioned and unconditioned stimuli or when a behavior occurs between the operant response and reinforcement. • Long-delayed learning occurs as the absence of concurrent interference • Interference is observed if other tastes are introduced.

26. Flavor Aversion Learning in Humans 26 • Many children in the early stages of cancer develop flavor aversions before toxic chemotherapy. • Adult and child cancer patients receiving radiation therapy. • Causes weight loss in these individuals. • Mapletoff ice-cream as a surrogate

27. Imprinting 27 • Imprinting • The development of a social attachment to stimuli experienced during a sensitive period of development. • Lorenz (1952) found that infant birds form attachments to the first moving object they encounter. • Birds may imprint to inanimate objects as well as animals of another species. • Conditions influences the likelihood of imprinting.

28. Conditions Influence Imprinting 28 • Klopfer (1971) found that ducklings imprinted more readily to a moving object than a stationary object. • Harlow (1971) studied this phenomenon in nonhuman primate surrogate, cloth mothers. • Ainsworth (1982) has studied the effect of imprinting on human infants. • Imprinting can still occur after sensitive development periods when sufficient experience is given. • The sensitive period for attachment differs among species.

29. Sexual Preference 29 • The sexual preference of many birds is established during the sensitive period. • Does not have to be of the same species. • Sexual preference, thus, does not depend upon sexual reinforcement. • Is not modified even after sexual experience with another bird species.

30. Nature of Imprinting 30 • Moltz (1960, 1963) proposed that Pavlovian and operant conditioning are responsible for social imprinting. • Before the fear system develops, chicks orient to large, familiar and unfamiliar objects (e.g., the mother) with low levels of arousal. • Fear system develops, unfamiliar objects elicit high arousal. • Chicks cling to their mother associated with lower levels of arousal

31. 31 • Fear reduction may be associated with “mama” in young human and nonhuman primates • Harlow (1971) used inanimate surrogate mothers of different forms (both wire and cloth) for nonhuman primate infants. • Primates clung to the cloth surrogate in the presence of a dangerous object, but fled when only the wire surrogate was present.

32. 32 • The research of Ainsworth and colleagues: • Secure relationship • The establishment of a strong bond between a mother who is sensitive and responsive to her infant. • Anxious relationship • The relationship developed between a mother and her infant when the mother is indifferent to her infant.

33. 33 • Instinctive view of Imprinting • The view that imprinting is a genetically programmed form of learning. • Kovach and Hess (1963) found that, despite its administration of electric shock, chicks still approached the imprinted object. • Punishment may not inhibit imprinting. • Primate infants clung to abusive “monster mothers” even as they were abused (Harlow, 1971).

34. Brain Mechanisms of Reward 34 • Electrical Brain Stimulation • Brain stimulation can be used as reinforcement. • Many species will act to earn brain stimulation. • Medial Forebrain Bundle or MFB (James Olds)

35. Characteristics 35 • Has 4 characteristics: • Highly reinforcing • Motivates ongoing behavior • Its functioning is stimulated by the presence of reinforcers • Its reinforcing effects are enhanced by deprivation

36. 36 • Stimulus-bound behavior • Behavior tied to the prevailing environmental conditions and elicited by stimulation of the brain’s reinforcement center. • Activation of the MFB reinforces behavior. • Watching erotic films leads to stimulation of the MFB and sexual activity. • Also has been shown to eliminate pain in cancer patients. • Produces a strong euphoria that lasts several hours.

37. “Liking” versus “Wanting” 37 • Hypothesis #1: Hedonia, dopamine (DA) acts as a “pleasure neurotransmitter”. • drugs of abuse are involved dopamine activity, particularly in the "high" or euphoric state • However, not all rewards or pleasurable things involve activation of the reward system • Hypothesis #2: Incentive salience (wanting, “do it again” or “craving”) stands out as a possible role for dopamine as it regard.

38. Mesolimbic Reinforcement System 38 • The MFB is only part of the brain’s reinforcement center. • Mesolimbic reinforcement system • A central nervous system structure that mediates the influence of reinforcement on behavior. • Tegmentostriatal pathway and nigrostriatal pathway.

40. 40 • Tegmentostriatal pathway • A neural pathway that begins in the lateral hypothalamus, goes through the MFB and ventral tegmental area, terminates in the nucleus accumbens, and governs the motivational properties of reinforcers. • Ventral tegmental area (VTA) • A structure in the tegmentostriatal reinforcement system that projects to the nucleus accumbens.

41. 41 • Nucleus accumbens (NA) • A basal forebrain structure that plays a significant role in the influence of reinforcement on behavior. • Nigrostriatal pathway • A neural pathway that begins in the substantia nigra and projects to the neostriatum and that serves to facilitate reinforcement-induced enhancement of memory consolidation.

42. 42 • One line of evidence of DA influence is the powerful reinforcing properties of amphetamine and cocaine, which increase the level of activity at dopaminergic receptors. • Animals quickly learn behaviors to self-administer amphetamine and cocaine. • Natural reinforcers (e.g., food and water) also trigger dopamine release, as does MFB stimulation.

43. Opiate Activation of the Tegmentostriatal Pathway 43 • Opiate drugs also stimulate the tegmentostriatal pathway. • Animals learn to self-administer opiate drugs such as heroin and morphine. • Opiate drugs do not activate DA receptors. • Both DA and opiate receptors produce activation in the NA.