430 likes | 570 Views
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
E N D
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? versus 1950s 1990s
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
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)
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 touch skin SN MN record MN activity to assay habituation gill Stage 1 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 • Spontaneous Recovery • Dishabituation • Generalization
Spontaneous Recovery Stimulus Hi Response Time Passes Lo Number of Presentations
Dishabituation Stimulus Novel Event (no time passes) Hi Response Habituation Dishabituation Lo Number of Presentations
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
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
Conditions Favouring Habituation • Calm organism • Shorter interstimulus intervals • Less variable interstimulus intervals • Low intensity • Less complexity • More trials
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) Low LG-ABN mothers High 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
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.