CHAPTER 3: Flashcards
Habituation
Decrease in strength or occurrence of behavior after repeated exposure to same stimulus.
When you first move in to a new house, the neighbors’ dog barking annoys you. But over time you get used to it and eventually, you will sometimes not even notice it.
Learning about repeated events:
Novel events are arousing
Regulated by the form of stimulus, the number of exposures, and time between exposures
Orienting Response
Innate reaction to novel stimuli
Fixation time
Acoustic Startle Reflex
Defensive response to loud, unexpected noise
Loud noise startles the rodent initially, but responses to the same noise will subsequently decrease.
Why Habituate?
Stimuli are now familiar & predictable
Avoid wasting time and energy
It’s stressful to be overwhelmed by all the stimuli present.
We are able to be more aware of other more important/novel stimuli
Risks to Habituation
Danger may lurk in unattended stimuli
Little boy cries wolf. The towns people habituate to the false alarms, such that when it is real, they don’t pay attention.
Habituation increases in response to…
- less arousing events
- when stimulus has been presented multiple times
- exposures are separated by short intervals.
Habituation is Regulated by…
the form of stimulus,
the # of exposures, and
the time between exposures
Habituation differs from non-learning situations such as ____ and ____
Habituation differs from non-learning situations such as adaptation and fatigue.
Adaptation (sensory) and Fatigue (motor) are types of diminished response that aren’t as cognitive
Habituation is learning-dependent independent of sensory and motor neurons.
Stimulus Specificity
Subject perceives that new stimulus is different from the habituated stimulus
Object discrimination in infants
Can be used to assess Perceptual capabilities of subjects
Stimulus Generalization** Infants and attending
Dishabituation
Recovery of behavioral response when new (novel & arousing) stimulus presented
Coolidge Effect
Mr. and Mrs. Coolidge, poultry breeding…
Think of the Acoustic Startle Reflex that rodents show to noise.
Rodent sex:
Males have much more sex when presented with new females than if they are paired with the same female.
Human Sexual Dishabituation?
The relationships subjective and physical arousal relationships in males are very directly related.
This not true at all for women.
For women, arousal is more cognitive.
That’s why women don’t really have a female version of men’s Viagra.
Male arousal is subject to habituation.
Females do not habituate as strongly to sexual stimuli.
Is this why men tend to cheat on their relationships more?
Maybe, maybe not.
Sensitization
Startling stimulus leads to stronger response to subsequent stimulus, more than would have normally been evoked
Hurricane Katrina sensitized people to subsequent hurricanes, such that subsequent less serious hurricanes caused mile-long traffic jams as people panicked and tried to get out of the area.
Habituation
vs.
Sensitization
Sensitization:
- GENERAL to a VARIETY of stimuli and responses.
- Results in INCREASED response magnitude.
- Occurs only after EMOTIONALLY arousing stimuli.
- Normally lasts for only SHORT period of time
Habituation:
- SPECIFIC to a PARTICULAR stimulus and response.
- Results in DECREASED response magnitude.
- Occurs after REPETITION of a variety of stimuli.
- Exhibited BOTH short term and long term.
Dual Process Theory
The idea that Habituation & Sensitization are two forms of learning that are independent but operate in parallel
One’s response to stimulus reflects combined effects of habituation and sensitization.
Exposure Weakens Connection
Habituation
Exposure Strengthens Connection.
The ability of a certain stimulus, as well as stimuli that are similar to it, to trigger a response increases.
Sensitization
Perceptual Learning
Experience with a set of stimuli makes the same stimuli easier to distinguish
Increased ability to make fine distinctions between highly similar stimuli
Discrimination learning
Assessing the gender of a chick;
Eventually you begin to recognize
More accurate when appropriate feedback is given
Learning Languages
Coke versus Pepsi example:
They taste a lot alike on the first time of trying pop in general.
But soda drinkers can tell the difference.
Mere Exposure Learning
Learning without explicit training
A type of Latent Learning
Learning occurs Independent of training or reward
Experimental group rodents grow up surrounded by to–be-descriminated figures on cage walls.
Control group rodents don’t experience the figures until discrimination traintin during adulthood
The experimental rodents were exposed to the neutral stimuli of the shapes for awhile before being rewarded for discriminating the shapes from each other. In the tests, they did better than controls.
Dog training: fine differences
Discrimination Training:
Learning Specificity
Learning Specificity:
Learning about one group of stimuli does not transfer automatically to another group of stimuli.
Like from dogs to chickens.
Difficult discrimination = Greater specificity
Subjects improve to near perfect ability to detect subtle differences.
Perceptual skills don’t generalize much: learning specificity
Feedback is critical.
Have to know if ne is wrong or right to improve
Learning through Exploration
Organisms can exert control over the kinds of stimuli they repeatedly experience.
Spatial Learning and Rat Mazes
Spatial Learning
Acquisition of information about one’s surroundings
Mere exposure learning: only evident at test
Exposure-first group:
First 10 days: the animals are just moving around. No reinforcement or encouragement.
Just moving through the environment led the animal to learn about its environments
The exposure-first group did better than the group that was trained the entire time
Niko Tinbergen: Landmark based learning; bees & displaced nests
In humans: Men are much more likely to use spatial cues than women
Niko Tinbergen
Landmark based learning
bees & displaced nests
Spatial Learning
In humans: Men are much more likely to use spatial cues than women
Novel Object Recognition
Most animals generally prefer novel objects and situations
Familiarity: A sense of sameness (William James, 1890)
Neophobia:
Active avoidance of novel objects.
Dolphins do not like novelty.
A sense of sameness
Familiarity
Priming
Prior exposure to stimulus improves ability to recognize same stimulus later (even minus the sense of familiarity)
Priming does not require explicit memory of primed stimuli
Priming & Amnesiacs
Do anterograde amnesic patients show priming effects?
YES!!!
The amnesiacs perform almost identically with the control group of regular people in a Priming experiment.
Priming does not require explicit memory of primed stimuli
Anterograde Amnesia:
inability to form new declarative memories following hippocampal damage
Remember these Points!
Perceptual learning: recognition and discrimination.
The finer the discrimination, the less generalization that will occur.
Priming: setting yourself up to respond in a particular way
People living in the city walking past homeless people: Habituation
Wine tasters:
Discrimination Learning
Brain Substrates??
Pavlov found that decorticated dogs do not habituate to auditory stimuli…
So we need the cortex to inhibit orienting responses??
Spinal cats do habituate to body tactile stimuli…
So cortex in not required???
How to Reconcile?
When the auditory stimuli comes to the brain, it has to be translated before it can translate to motor action.
But the touching the body…
Learning with Aplysia:
Giant sea slug
Invertebrate learning offers a simpler system in which to isolate neurobiological correlates of learning
Giant sea slug:
Simple nervous system (~20,000 neurons).
Neuronal development is hard-wired, does not very from slug to slug.
Identifiable individual neurons.
24 sensory neurons, 6 motor neurons
Gill withdrawal: Sensitization
