pulsepacket_generator – Generate sequence of Gaussian pulse packets¶
Description¶
The pulsepacket_generator
produces a spike train contains Gaussian pulse
packets centered about given times. A Gaussian pulse packet is a given
number of spikes with normal distributed random displacements from the center
time of the pulse. It resembles the output of synfire groups of neurons.
All targets receive identical spike trains.
New pulse packets are generated when activity or
sdev
are changed.Gaussian pulse are independently generated for each given pulse-center time.
Both standard deviation and number of spikes may be set at any time. Pulses are then re-generated with the new values.
All stimulation devices share the parameters start
and stop
,
which control the stimulation period. The property origin
is a
global offset that shifts the stimulation period. All three values are
set as times in ms.
For spike-emitting devices, only spikes with times t that fulfill \(\mathrm{start} < t \leq \mathrm{stop}\) are emitted. Spikes that have timestamp of \(t = \mathrm{start}\) are not emitted.
For current-emitting devices, the current is activated and deactivated such that the current first affects the target dynamics during the update step \((\mathrm{start}, \mathrm{start}+h]\), that is, an effect can be recorded at the earliest at time \(\mathrm{start}+h\). The last interval during which the current affects the target’s dynamics is \((\textrm{stop}-h, \textrm{stop}]\).
The property stimulus_source
defaults to an empty string. It can
be set to the name of a stimulation backend, in which case it will
take its parameters from the configured backend instead of from the
internally stored values. More details on available backends and their
properties can be found in the guide to stimulating the network.
Parameters¶
- label
A string specifying an arbitrary textual label for the device. Stimulation backends might use the label to generate device specific identifiers like filenames and such. Default:
""
.- origin
A positive floating point number used as the reference time in ms for
start
andstop
. Default:0.0
.- start
A positive floating point number specifying the activation time in ms, relative to
origin
. Default:0.0
.- stimulus_source
A string specifying the name of the stimulation backend from which to get the data for updating the stimulus parameters of the device. By default, the device uses its internally stored parameters for updating the stimulus. Default:
""
.- stop
A floating point number specifying the deactivation time in ms, relative to
origin
. The value ofstop
must be greater than or equal tostart
. Default:infinity
.
- pulse_times
List of times of the centers of pulses in ms.
- activity
Number of spikes per pulse. Default:
0
.- sdev
Standard deviation of spike times in each pulse in ms. Default:
0.0
.
Setting parameters from a stimulation backend¶
The parameters in this stimulation device can be updated with input coming from a stimulation backend. The data structure used for the update holds one value for each of the parameters mentioned above. The indexing is as follows:
activity
sdev
pulse_times
Sends¶
SpikeEvent