Lecture 5-6 Flashcards
Habituation, Sensitivation & Familiarization
Habituation
A decrease in the strength or occurrence of a behavior after repeated exposure to the stimulus that produces that behavior
Researchers examine simple examples of habituation in the lab, and measures a single easily measurable response, such as the ____ ____ ____
acoustic startle reflex
Acoustic startle reflex
A defensive response (such as jumping or freezing) to a startling stimulus (such as a loud noise)
Orienting response
An organism’s innate reaction to a novel stimulus
Dishabituation
The renewal of responding after a new stimulus has been presented
(same stimulus to different organ and then back to the original organ: renewed response)
Habituation is ____ specific, meaning that habituation to one event does not cause habituation to every other stimulus in the same sensory modality
stimulus
How rapidly a response habituates and how long the decrease in responding lasts depend on several factors: How ____ the stimulus is, how many ____ it is experienced, and the ____ of time between repeated exposures
arousing; times; length
An exposure that is presented with closely spaced repetitions is a ____ exposure, and an exposure that is spread out over time is called a ____ exposure.
Massed; spaced
____-term habituation is those that last for only a few minutes or hours, while ____-term habituation lasts a day or more
short; long
Spontaneous recovery
A stimulus-evoked response that has habituated reappears after a period of no stimulus presentations
(Stimulus to the same organ after resting period)
Stimulus specificity
Habituation to one stimulus does not cause habituation to other stimuli
Sensitization
Phenomenon in which an arousing stimulus leads to stronger responses to a later stimulus
Familiarity
The perception of similarity that occurs when an event is repeated
Priming
Phenomenon in which prior exposure to a stimulus can improve the ability to recognize that stimulus later
Perceptual learning
Lerning in which repeated experiences with a set of stimuli make those stimuli easier to distinguish
Latent learning
Learning that is unconnected to a consequence and remains undetected until explicitly demonstrated at a later stage
Cognitive map (Edward Tolman)
An internal psychological representation of the spatial layout of the external world
How does these groups perform in the matrix?
a) Rats never rewarded
b) Rats always rewarded
c) Rats rewarded on Day 11
a) never rewarded: error rate decrease slowly and gradually flattens out at ~6 errors
b) always rewarded: eror rate decrease faster and drops to ~2 errors by day 17
c) rewarded on Day 11: same decrease rate with never rewarded rats at the start, starting day 11 see a drastic decrease and by day 14/15 reaches ~1 error
Subregions of the hippocampus include: ____ ____ (DG), ____ ____ 3/1 (CA 3/CA 1), and ____ (Sub)
Dentate gyrus, cornu ammonis, subiculum
How to measure firing rate (Hz) of a neuron?
of action potentials/duration of time
Spatial ratemap
Firing rate of a neuron is represented as a function of space
Place field
In a spatial ratemap, a small area of increased activity
Place cell
A neuron with spatial coding that increases activity in a spatial ratemap
Where are place cells found in the brain?
Hippocampus
____ ____ are created regardless of task demands. A ____ ____ will be created even if the rat is simply walking around the maze without purpose. It can then be searched for a solution when required. Altogether, this forms the neural basis of latent learning.
Place fields; cognitive map
The withdrawal reflex in Aplysia gill:
1. ____ input to the siphon (or tail or mantle) will activate respective ____ neurons.
2. ____ neurons release the neurotramitter ____ at synapses onto ____ neurons.
3. ____ neurons innervate muscles that retract the gill
- Somatosensory; sensory
- Sensory; glutamate; motor
- motor
In habituation, sensory neurons release ____ amount of glutamate into motor neuron, resulting in ____ amount of spikes in motor neurons, leading to less gill muscle movement. This constitutes the neural mechanisms of habituation.
decreased; decreased
Aplysia gill withdrawal reflex is an example of synaptic depression, which means…
Reduction in synaptic transmission
In Aplysia gill withdrawal reflex, how does number of action potentials relate to the effect of spikes on postsynaptic neurons?
number of action potentials remains the same, but each spike has less effect on the postsynaptic neuron
Homosynaptic plasticity
Specific to synapsese involved in habituation
____ presentation of stimuli over multiple days results in change in ____ of synapses/number of ____ terminals onto ____ neurons, thus reducing excitatory drive onto motor neurons. (constitutes ____ term habituation)
Spaced; number; presynaptic; motor; longer
Neural circuits in Aplysia gill: Withdrawal reflex
Touching siphon stimulates and activates ____ neuron S, which then releases less ____ with each action potential, thereby causing less ____ of ____ neuron M, therefore the gill muscles are not activated as much as the gill is withdrawn less
Sensory; glutamate; excitation; motor
Sensitization in Aplysia
____ excited by tail sensory neuron synapses on siphon & mantle sensory neurons are called ____-____ synapse, which releases ____ (neuromodulator), which results in greater number of ____ vesicles, resulting in greater ____ of motor neuron.
axo-axonic; serotonin; glutamate; excitation
____ ____: Plasticity occurred at the siphon and mantle sensory neuron synapses onto the motor neuron (different pathways). This is demonstrated by ____ in Aplysia.
Heteroplasticity; sensitization
____ ____ is the process of altering synaptic transmission at synapses not involved with processing the initial stimulus
Heterosynaptic plasticity
