Presentation on theme: "Chapter 2: Elicited behavior, Habituation, and sensitization"— Presentation transcript:
1 Chapter 2: Elicited behavior, Habituation, and sensitization behavior is a reaction to a stimulus in the environment.Food salivationBright light pupil dilation.
2 The simplest form of elicited behavior is the reflex. Components of a Reflex ArcAll reflex arcs have five essential components1. receptorreacts to a stimulus.2. The sensory (afferent) neuronconducts message to CNS3. The integration centerconsists of one or more synapses in the CNS.4. The motor (efferent) neuronconducts from CNS to an effector.5. The effector,muscle fibers or glands,contracts or secretes.
4 The reflex arc just described = simplest situation. Often other neural connections are involved.Notice that the Reflex arc does not require any willful conscious act Thus - elicited
5 Animals with reflexive tendencies had an advantage Reflexes appear to have evolved to protect the well being of the organism.withdrawal from paineyeblinkpupillary reflexSneeze, cough, vomitpatellar reflexrooting reflex.salivationrelease of digestive fluids.Animals with reflexive tendencies had an advantage
6 Ethology and Modal Action Patterns Ethologists study the role of behavior within the context of species-specific behaviors.This is in contrast to the general processes approach used by most psychologistsEthologistsbehavior is generally instinctive.often study animals in the wild rather than the laboratory
7 Consummatory behaviors behaviors that are crucial for survival.feeding, courting, reproducing, and care for offspring.innate, genetically determined survival behaviors.For ExampleImprinting.Konrad Lorenz Why do geese imprint, but other birds/animals (robins) do not?Precocial vs Altricial?
8 1. The object must be moving Ethologists try to find the variables that are responsible for eliciting the behavior.imprinting = two important factors.1. The object must be movingdoesn’t matter if it is living or notultra lights2. The imprinting must occur within a critical period(13-16 hours after hatching).Critical Period for learning some things for humans?language
9 Modal Action Patterns. (MAP’s) MAPs vs Reflexes modern Ethology abandoned the term instinctMAPs vs ReflexesMAPs aremore complexconsist of a long series of reflex-like actsmore variable, though still stereotypicless likely to be evident at or soon after birth.
10 In addition, to qualify as a MAP, a behavioral sequence must meet four specific criteria according to Moltz (1963)1. Stereotypedoccurs the same way each time2. continue to completion once begundifficult to disrupt3. latent periodonce completed, some time must pass before behavior appears again4. innatethe animal must perform the full integrated behavioral sequence the first time its elicited
11 Like Reflexes MAPs are highly adaptive Protection from predators Cat – arch back, fluff hair, hissProtection against the elementsMigrationhibernationgetting foodPigs rootingspider webscourtship and matingBig Horn SheepDuckscare for youngBirdsNestsGathering foodWasps that capture spiders
12 Modal Action Patterns are released by a sign stimulus a specific environmental event that triggers an MAPFemale pheromones often trigger mating behavior in malesThe sign stimulus works like a key to unlock an innate releasing mechanisminnate releasing mechanisma neural mechanism that is stimulated by a sign stimulus.controls the modal action pattern
13 Examples Geese with Eggs Birds feeding young Herring gull studies Rolling away?What if it slips on way back?stereotypedLarger eggs?Supernormal stimuliBirds feeding youngCowbirdsHerring gull studiesWhich beak works best?
21 Do humans exhibit Modal Action Patterns? sleep?Stereotyped?continue to completion once begun?latent period?Innate?emotions?sex?
22 Effects of Repeated Stimulation Descartes thought that a reflexive response would occur the same way each time it was elicitedHowever – elicited behavior are not invariantHabituation.repeated exposure to a stimulus reduces responding to that stimulus.
23 Habituation is a very simple form of learning Very useful tool for understanding animal and infant behavior.Can you distinguish between “ba” and “pa”Infants?Used suck rate as responsePacifier with an embedded switch
24 As simple as habituation is, it can be used to tell us a lot about a nonverbal organism Other race effectCaucasian infants (3.5 months old)Group 1 (Caucasian faces)shown a Caucasian face until habituatedGroup2 (Asian faces)Shown an Asian face until habituatedTestBoth groups shown novel facesNew Caucasian face for group 1New Asian face for group 2
26 Repetitive stimulation does not always cause habituation. HOWEVER,Repetitive stimulation does not always cause habituation.sometimes you get sensitization.My father and motorcycleemotional responsefleedo not habituatelikely to be more responsive to other stimuli.tap on the shoulderdrop a wrench. My dog and car AC
27 Davis (1974)sensitization and habituation to the same stimulus.110 db noise = loud.Gp1 = rats housed in a quiet chamber = 60 dbGp 2 = rats housed in a loud chamber = 80 dbOne of the groups decreased their startle response to the 110 db noise after repeated presentations.The other group increased their startle response to the 110 db noise after repeated presentations.Which group is which?What phenomenon does each group demonstrate?
28 What determines whether we get habituation or sensitization? Dual process theoryTwo simultaneous processesS-R systemReflex arcState systemInvolves additional parts of the nervous system that regulate levels of arousal
29 The S-R system and State system are additive – but in opposite directions The more active system will determine whether habituation or sensitization is displayedExampleCheckerboard study in book.Infants shown checkerboards4 x 412 x 12
31 Habituation versus Sensory Adaptation and Response Fatigue Bright light – blindedLoud noise – can’t hearResponse FatigueToo tired to move
32 Figure 2. 13 – Diagram of a simple reflex Figure 2.13 – Diagram of a simple reflex. Sensory adaptation occurs in the sense organs, and response fatigue occurs in effector muscles. In contrast, habituation and sensitization occur in the nervous system.
33 Characteristics of Habituation Habituation is response specific Some parts of responding may habituate – but others continue to operate.Announcement while taking a testLook uporienting responsequickly habituatesYou will likely still be listening however = other responseListening not habituatedHabituation is stimulus specificStop responding to one thing, but if there is a change in the stimulus the habituation goes away.Dishabituation
34 Time course for habituation Short-term = seconds to minutesLong-term = may persist for many daysLeaton (1976)Startle response in rats to loud high pitched tone