281 Unit 2

• Stimulus – an energy change that affects an
• organism through its receptors

• Receptor – an organism that converts enery
• changes in its environment into nerve impulses

Because it is often overlook inthe analysis of a more complex phenomenon

• The action of an organisms
• effector

Kinesis

• An unlearned functional relation
• between a stimulus condition and the speed of movement irrespective of
• direction

Taxis

• An unlearned functional relation
• between a stimulus and movement toward or away from the stimulus

Fixed action pattern

• An unlearned ridged sequence of
• responses that once started, continues to occur regardless of the effects of
• the separate responses on the environment.

• Duck will imprint to anything
• medium sized and can be operantly conditioned to move away from the object

• Reference input -Thermostat
• setting

Comparator - Thermostat

Action system - Furnace

Output - Hot air

Actual input - Air temp

Distubance - Open window

Sensory neurons detect stimuli

• That info travels to the
• interneurons

• Interneurons send the info through
• the spinal cord to the motor neurons which excite the muscle fibers causing a
• reflex

• It is a part of the repertoire of
• all members of a species (may be species specific)

• Bx is not the result of prior
• learning

• Bx has a rigid sequence that once
• started, will complete regardless of if it is necessary in the current context

• The sign stimulus initiates a
• Fixed action pattern

• Watson believed there were no
• innate human abilities and that environment was the most impactful in
• determining how people behave

• Pinker believed humans had innate
• abilities such as language and emotional expressions

All kids babble

• All cultures can correctly
• identify emotions portrayed in pictures

• FAP once initiated will continue
• until completion

• Reaction chains require an
• external stimulus at each step in the sequence to continue until completion

• Human universals unlike innate
• bxal characteristics are influenced by learning and may have different
• topographies or physical characteristic but they universally server the same
• function

Dance, music

• Decrease in strength of response
• after repeated presentations of the stimulus that elicits that response

It is stimulus specific

• Habituation allows organisms to
• disregard unimportant stimuli

• Course of habituation – repeated
• presentations of the stimulus brings large decreases in the response at first
• and smaller decreases there after

• Effect of time -Response will
• recover if stimulus is withheld for some time.
• The longer the absence the larger the response

Relearning effect

• After a period of time without
• the stimulus, habituation upon representation will happen more rapidly

Effect of stimulus intensity

• Habituation occurs slower or not
• at all with intense stimuli

Occurs faster with weak stimuli

Effects of overlearning

• The more presentations of the
• stimulus before the withholding period the and after there is no more
• observable change in Bx the longer the retention of habituation

Stimulus Generalization

• Habituation generalizes to
• similar stimuli

Two processes a and b

• A is the initial reaction to stimuli
• which is large

• B kicks in later but stays high
• longer which opposes a and bring emotional state back to baseline

In repeated presentation

• A
• peaks but not as drastic

• B immediately kicks in and has a
• more drastic increase

Pets scans

FMRI