Spike trains Flashcards
What is typical methods for decoding of spike trains?
Discretization of time and binning of results
A trial refers to the response to a single presentation of stimulus, what follows this?
Superimpose the trials with the stimulus times
Divide time into small intervals
Plot the spike count in each bin
When is a spike triggered average used?
When there is a continuous stimulus
What does the spike triggered average show?
It shows the average value of the stimulus at different amounts of time before a spike.
If there is a time dependent stimulus s(t) and the N spikes at times ti the spike triggered average is ..
S(tau)=1/N *sum(s(ti-tau))
In other words it gives the average amount of stimulus a time tau before a spike.
What does an autocorrelogram show?
Shows how the behaviour of a spike train is related to its behaviour at a different time.
What is an autocorrelogram used for?
To detect periodic behaviour in spike trains. A periodic spike train will have gaps between spikes related to the period.
How do you calculate an autocorrelogram?
Divide time in to small bins of size ∂t
Count how many spikes are separated by a time between n∂t and(n+1)∂t and put them in the nth bin
Plot the histogram
What is a cross correlogram
A cross correlogram is useful for measuring the relationship between the spiking in two neurons; it might give an indication that one neuron may be influential in causing the other to spike or it might show that both neurons are entrained to the same periodic behavior
How do you calculate a cross correlogram?
Divide time into small bins, of length ∂t say.
• Count how many spikes from neuron two are found between n ∂t and (n + 1) ∂t compared
to the a spike from neuron one.
• Plot the histogram.
What is the Tuning curve and what is it used for?
The tuning curve is used to related the response to a family of stimuli parameterized by a single variable. The tuning curve is a plot of the firing rate against the parameter
What is the following equation:
d’=(µ2-µ1)/sigma
A measure of how different two distributions are
