Elicited or Unconditioned Behavior Occurs without past experience Modifiable with experience (examples: habituation and sensitization Some Types of Elicited Behaviour An eliciting or unconditioned stimulus elicits a response without any prior learning Types of Elicited Behaviour Simple Reflex Orienting Reflex Taxis (taxes) Kinesis (kineses) Fixed/Modal Action Patterns FAPs/MAPs Sequence of behaviors directed at the eliciting (sign or releasing) stimulus Sometimes requires underlying drive (hydraulic model) Vigor of response depends on how closely the sign stimulus corresponds to the ideal stimulus (e.g., cute baby) Small (non-ideal) Normal (ideal) Supernormal (exaggerated ideal) Supernormal stimulus An accurate 3-dimensional model of a herring gull's head (a), and a 'supernormal' bill (b). Supernormal stimulus Supernormal stimulus? versus 1950s 1990s Habituation a simple type of learning which is shown by a change in elicited behaviour over trials defined as a reduction in responsiveness (frequency, magnitude) over successive trials sometimes short-lasting and sometimes long lasting Habituation-One Type of Modifiability Eric Kandel and Aplysia Kandel`s Experiments Touch Siphon Gill Withdrawal Habituation gill withdrawal touch Forms of Habituation Short-Term lasts only a few minutes best if stimulus applied at short intervals (2-s) Long-Term lasts weeks best if stimulus applied at longer intervals (30-s) Simplified Circuit What’s the Mechanism of Short-term? decreases in synaptic transmission loss of skin sensitivity decrease in motor synapse fatigue Not Muscle Fatigue Spontaneous Evoked Pinsker et al., (1970) Science 167:1740 What’s the Mechanism of Short-term? decreases in synaptic transmission loss of skin sensitivity decrease in motor synapse fatigue Not Motor Synapse Before skin SN After electrical MN record gill Kupfermann et al., (1970) Science 167:1743 What’s the Mechanism of Short-term? decreases in synaptic transmission loss of skin sensitivity decrease in motor synapse fatigue Not Skin Sensitivity Stage 1 touch skin SN MN record MN activity to assay habituation gill Kupfermann et al., (1970) Science 167:1743 Not Skin Sensitivity touch skin SN block MN record MN activity to assay habituation gill Kupfermann et al., (1970) Science 167:1743 What’s the Mechanism of Short-term? decreases in synaptic transmission loss of skin sensitivity decrease in motor synapse fatigue Mechanism of Short-term Habituation Decrease in neurotransmitter released at the synapse with both the motor neuron and the interneuron! Mechanism of Long-Term Habituation Change in the number of synapses! Some Properties of Habituated Responses 1. Spontaneous Recovery 2. Dishabituation 3. Generalization Spontaneous Recovery Hi Response Stimulus Time Passes Lo Number of Presentations Dishabituation Hi Response Stimulus Novel Event (no time passes) Habituation Dishabituation Lo Number of Presentations Generalization Sensitization- Another Type of Modifiability enhanced response to a “benign” stimulus after exposure to a “noxious” one (most common) for example, startle enhanced response after repeated presentations of a “not so benign” stimulus (less common) for example, kindling Rat Startle Human Startle Kindling repeated stimulation of hippocampal cells increases responsiveness after being sensitized, very little stimulation is required to produce the seizures related to epilepsy Dual Process Theory Competition between two separate processes 1. S-R System: Habituation 2. State System: Sensitization Examples S S + + NET - - H NET H Trials Trials Conditions Favouring Habituation 1. 2. 3. 4. 5. 6. Calm organism Shorter interstimulus intervals Less variable interstimulus intervals Low intensity Less complexity More trials Interstimulus Interval Complexity Looking Time Trials Imagine……… Kendra is an overly anxious person. She worries about the smallest things. Some examples of the unpleasant symptoms she experiences include excessive sweating, heart palpitations, and a fitful sleep. Her anxiety places her at risk for depression, heart disease, and diabetes. A genetic test reveals Kendra has a vulnerability in the promoter region of her serotonin transporter gene. Her doctor tells her that if her mother had been more loving and attentive when Kendra was younger, she might have been calmer. The doctor maintains experience can program calmness, and calmness acquired by experience is inheritable. Gene Expression-A third Type of Modifiability Genes affect bodily processes, including emotional regulation Two copies of the “short” version of a promoter for the serotonin transporter gene is a risk factor Maternal Behavior licking and grooming (LG) and arched-back nursing (ABN) High LG-ABN mothers Low LG-ABN mothers Attentive Mothering Licking and arched-back nursing by mother an immediate “calming” effect on baby rats in the first week after birth a long-term reduction in stress responsiveness the promoter for the short version of serotonin transporter gene is “switched on” by attentive mothering so, a vulnerable pup with two short copies of the promoter for the serotonin transporter gene is cured by its mother’s licking (short gene works better) this environmental effect is passed along to the pup’s own offspring Brain of Vulnerable Baby Rat high LG-ABN mother short gene expressed less anxiety Cross-fostering Studies Imagine……… Kendra’s doctor gives her a prescription for a pill that will promote the activity of the malfunctioning gene. No other therapy is necessary. Kendra’s children inherit the faulty gene, but its function is enhanced.