Presentation on theme: "The Nature of Elicited Behavior"— Presentation transcript:
1 The Nature of Elicited Behavior Elicited Behavior: Behavior in response to a stimulusBecause of preexisting organization of the nervous systemFrom the simplest reflexes to the most complex behavior sequencesReflexes consist of eliciting stimulus and corresponding responseprovide rapid behavioral adjustment to environmental events likely to be encountered.The response rarely occurs in the absence of the stimulusReflex Arc (simple reflex) is mediated by minimum of three neuronsSensory NeuronInterneuronMotor NeuronHowever not all reflexes are simple reflex arcs with simple circuitsstartle reflexJump when you hear a loud sound,requires complex circuits including auditory circuit, processing circuit and motor circuit each of which contains several neuronsMore complex behaviors such as running away from a grizzly bearconsists of a combination of reflexes including hormonal, emotional and cognitive processing to the extent that it is difficult to determine the role of reflexes.
3 Functional value of some common reflexes Withdrawal Reflex; pulling away from painful stimulusPatellar Reflex is a stretch reflex that is part of a large set of proprioceptive signalsStartle reflex (video) is a whole body response to a sudden stimulusPupil dilation/contraction in response to light intensityMuch of the behavior repertoire of new infants (sucking, head turning, respiratory occlusion reflex)Some reflexes in infants disappear with maturationMoro reflex when the head is released suddenly the arms should move sideways with the palms up and the thumbs flexedSucking reflex: sucking when the area around mouth is touchedStartle reflex: pulling arms and legs in after hearing loud noiseStep reflex: stepping motions when sole of foot touches hard surface
5 Functional value of some common reflexes Much of the behavior repertoire of new infants (sucking, head turning, respiratory occlusion reflex)Others are precursors to mature behaviorRooting Reflex when you stroke the baby's cheek. The infant will turn toward the side that was stroked and begin to make sucking motions with the mouthGrasping reflex occurs if you place a finger on the infant's open palm. The hand will close around the fingerAnd yet others are examples of reflexes that last into adulthoodBlinking reflex -- blinking the eyes when they are touched or when a sudden bright light appearsCough reflex -- coughing when the airway is stimulatedGag reflex -- gagging when the throat or back of the mouth is stimulatedSneeze reflex -- sneezing when the nasal passages are irritatedYawn reflex - yawning when the body needs more oxygenPower Point Presentation on Infant Reflexes and Stereotypies
6 Modal Action Pattern Fixed action patterns (Lorenz and Tinbergen) develop independently of the rearing environment and continue to completion even in the absence of guiding stimuli.Fixed-action-pattern of egg retrieval by greylag goose.archaic terminology replaced by modal action patternModal Action Pattern (MAP) Reflexive response sequences peculiar to a specific speciesSexual behavior such as nest building in birds or fishTerritorial defense such as guarding a boundary from intrudersAggression such as parents attacking intrudersPrey capture such as wolves chasing and catching deerMAP can be simple or complex and how they occur can depend on the feedback from the external environmentSimple egg retrievalMore complex courtship behavior includes the interaction of male and female
7 Fixed action pattern Modal action pattern Egg retrieval by greylag goose. Fixed action patterns are given independently of the rearing environment and continue to completion even in the absence of guiding stimuli.
8 Modal Action PatternMAP are elicited by Sign Stimulus or releasing stimulusHerring gull chicks peck at a red spot on parent's billTinbergen and Perdeck, (1950) Experiments where a yellow stick with red spots acts as a stimulus.Threshold for eliciting behavior varies with circumstancesthe same stimulus can have varying effects depending upon the physiologicalmotivational such as hungerhormonal influences such as breeding seasonThese patterns are not done exactly the same each time performedSupernormal stimulusartificially exaggerated sign stimulus that elicits an unusually vigorous responseis the most effective stimulus for eliciting behavior may not be those that occur under natural conditionsTimbergen 1948 Osytercather Supernormal Sign Stimuli using large eggsArtificial Eggs used by Baerends & Kruijt
10 Sign Stimulus Tinbergen and Perdeck, (1950) Herring gull chicks use a moving red spot on bill as a sign stimulus to recognize their mother.A yellow stick with red spots acts as a supernormal stimulus.
11 Supernormal Sign Stimuli A supernormal sign stimulus is one that mimics and “outdoes” normal sign stimuli.
12 Baerends & Kruijt Supranormal Egg Retrieval Model Value
13 Modal Action Patterns in humans? Eating behaviorOdor and taste of foodVisual cues of foodSocial and Sexual behaviorCosmetics, Perfume, ClothingTactile: touchOlfactory: pheromonesVisual: Eyebrow flashAre these “sign stimuli” ?Supra-normal stimuli effects on HumansArt, advertising, toys etc.Head size of dollsBody shape in artColor, size, shape, movement in advertising
15 Sequential Organization of Behavior Responses are organized into functionally effective behavior sequencesDistinctions made by early ethologists:Motivated behavior (foraging for food) involves appetitive behavior (early components)beginning of sequenceless stereotypedcan take on a variety of different forms depending on the environmentBring the organism into contact with stimuli that release (elicit) consummatory behaviorConsummatory behavior (end components)highly stereotypedand species-specific modal actions patternselicited by specific releasing stimuli
16 Sequential Organization of Behavior Examples: Foraging, Mating , Sexual activity, Territorial Defense and AggressionHumans: ForagingAppetitive: Type and method of food preparation varies across culturesConsummatory: chewing and swallowing the same across culturesHumans: AggressionAppetitive: Threatening behavior varies across culturesConsummatory: Hitting and hurting consistent across culturesForaging behavior organized into modes: (Timberlake 2001)general search modefocal search modefood handling modeAwareness of sequential organization of behavior in a given species is important because learning effects depend on which component of the behavior sequence is being modified.
17 Guarding Dog Anatolian Shepherd originated in the Anatolia region of central Turkeyresponsible for guarding livestock without human assistanceTraining a livestock-guarding dog is primarily a matter of raising the dog with sheep to establish a social bond between sheep and dogNeoteny: retain puppy like characteristicslicking the muzzle of an adultplay wrestlingbarking when something new or strange approachesabsence of predatory behavior
18 Effects of repeated stimulation Elicited behavior change with experienceDoes not occur exactly the same every time an elicited stimulus is encounteredVaries in intensity (and form)Varies in durationReflexive behavior changes with repeated presentations of eliciting stimulusSalivary response in humansStartle Response in RatsHabituation effects:Decrease in responsiveness with repeated exposure to a particular eliciting stimulus.Stimulus specificAffected by novelty or familiarity and complexity of stimulation
19 Effects of repeated stimulation Salivation and Hedonic Ratings of Taste in PeopleRepeated taste of lemon or lime see Figure 2.4Decreased salivationLower hedonic ratingsPeople find the taste of food to be less pleasant the more often they eat that foodHabituation to the taste of lemon yogurt see figure 2.5Habituation in average weight womenLess habituation in overweight womenVisual Attention in InfantsThe more novel and or complex a visual stimulus the more an infant looks with repeated presentation see Fig 2.7Facial familiarity in infants (3.5 months) see Figure 2.8Phase one: group one familiarized to side view, group two familiarized to frontal viewPhase two: each group tested with familiar face or novel faceEffected by the frequency