Intro to Learning - Chapter 2

Learning – Chapter 2  Nature of elicited behaviour o Irritation of respiratory passages causes sneezing and coughing o Behaviour occurs in response to stimuli –elicited  Elicited behaviour = reflexive behaviour o Concept of the reflex  Involves two closely related events  eliciting stimulus and corresponding response o stimulus and response are linked  specificity of relation between stimulus and accompanying reflex response is consequence of nervous system organization  environmental stimulus for reflex activates sensory organ (afferent neuron)  transmits sensory message to spinal cord o neural impulses related to motor neuron (efferent neuron)  activates muscles involved in reflex response  sensory and motor neurons rarely communicate directly  impulses from one to other are relayed through at least one interneuron  neural circuitry ensures that particular sensory neurons are connected to corresponding set of motor neurons  restricted wiring – restricted set of stimuli elicits particular reflex response  reflex arc  afferent neuron, interneuron and efferent neuron  represents fewest neural connections necessary for reflex action  respiratory occlusion reflex  stimulated by reduction of air flow to baby o when cloth covers baby’s face or accumulation of mucus in nasal passages o reactions  pull head back  face-wiping motion  crying involves vigorous expulsion of air  essential for survival o Modal action patterns  Simple reflex responses are evident in many species  Papillary constriction to bright light  Mammalian infants suck in response to object being placed near mouth  Herring-gull chicks just as dependent on parental feeding o Checks peck at tip of parent’s bill  Parents regurgitate  Chicks peck regurgitated food  Modal Action Patterns (MAP):  Response sequences typical of a particular species of particular species  Species-typical modal action patterns identified in many aspects of animal behaviour  Sexual behaviour  Territorial defense  Aggression  Prey capture  Threshold for eliciting these activities vary  Same stimulus have different effects depending on physiological state of animal and its recent actions  Lorenz and Tinbergen 1 Learning – Chapter 2  Species-specific action patterns as fixed action patterns to emphasize activities occurred pretty much the same way in all members of a species o Eliciting stimuli for modal action patterns  Fairly easy to identify in case of simple reflexes  Stimulus responsible for modal action pattern can be more difficult to isolate if response occurs in course of complex social interactions  Pecking by chicks may be elicited by colour, shape/length of parent’s bill, noises parent makes, head movements of the parent or other stimuli  Tinberg and Perdeck o Beak had to be long, thin, moving, downward facing object with contrasting red patch near tip  Sign stimulus or releasing stimulus  Specific features found to be required to elicit pecking behaviour  Once identified, can be exaggerated to elicit especially vigorous response o Supernormal stimulus  Exaggerated sign stimulus  Sign stimuli play major role in control of human behaviour  Also play major role in social and sexual behaviour o Sequential organization of behaviour  Responses do not occur in isolation of one another  All motivated behaviour involves systematically organized sequences of actions  Appetitive behaviour  Early components of behaviour sequence  Occur early in behaviour sequence and serve to bring organism into contact with stimuli that will release consummatory behavior  Less stereotyped and can take variety of different forms depending on situation  More variable and can be shaped by learning  Consummatory responses  End components of behaviour sequence  Completion of a species’ typical response sequence  Highly stereotyped species’ specific behaviours that have specific eliciting or releasing stimuli  Species-typical modal action patterns  Foraging for food  Appetitive response o General search mode  Occurs when subject does not know where to look for food o Focal search mode  Once it finds a source, it begins to search for the food in/on the source only  Consummatory response o Food handling and ingestion mode  Once the food has been found, then this mode activates  Effects of Repeated Stimulation o Reflex mechanism according to Descartes  Each occurrence of eliciting stimulus would produce same reflex reaction because energy of eliciting stimulus was transferred to motor response through direct physical connection  If this was true, it would be of limited interested to researchers o Salivation and hedonic ratings of taste in people  Taste of food elicits salivation as reflex response 2 Learning – Chapter 2  Salivation and hedonic ratings decreased with repeated trials  Habituation Effect o Decline in response with repeated stimulus presentation o Prominent feature of elicited behaviour evident in virtually all species and situations o Decrease in response specific to habituated stimulus only  Stimulus specific  Taste stimulus influences rate of taste habituations  Having attention directed to non-food cues keeps food from losing flavour through habituation o Visual attention in Human Infants  Visual cues elicit a looking response and can be measured by how long they keep their eyes on one object before shifting their gaze  Nature of change is determined by nature of stimulus  Sensitization is observed depending on complexity of the stimulus  People are experts at recognizing and remembering faces  Discriminate faces of their race better than different race o Other race effect  Visual attention paradigm became a prominent tool in study of infant perception as a more complex form of cognition  Provided a great deal of information about infant cognition o The Startle Response  Startle response is part of organism’s defensive reaction to potential or actual attack  Can be measured by measuring sudden movements  Used as their behavioural anchor  Stabilimeter chamber  Used to measure startle response in rats  Chamber rests on pressure sensors o When startled, rat jumps and jiggles the chamber  Indicators of the vigor of the startle reaction  Leaton  Testing sound startle response  Rats presented with a single tone once a day for 11 days  Most startling response observed the first time tone was presented o Less intense reactions the next 10 days  Presented more frequently (every 3 seconds) for 300 trials o Startle reactions quickly ceased when tone presentations occurred every 3 seconds o Dramatic loss was only temporary