simTSfmri: Simulate fMRI time series

In NeuroStat/neuRosim: Functions to Generate fMRI Data Including Activated Data, Noise Data and Resting State Data

Description

Simulates an fMRI time series for the specified design and noise type.

Usage

simTSfmri(design = list(), base=0, nscan = NULL, TR = NULL, SNR=NULL,
	 noise = c("none", "white", "temporal", "low-frequency", 
	"physiological", "task-related", "mixture"), type = c("gaussian", "rician"),
	 weights, verbose = TRUE, rho = 0.2, freq.low = 128, freq.heart = 1.17, 
	freq.resp = 0.2, vee=1)

Arguments

design	List generated by simprepTemporal specifying the design. If not specified, noise time series are generated.
base	Baseline value of the time series.
nscan	Number of scans.
TR	Repetition time in seconds.
SNR	Signal-to-noise ratio of the time series.
noise	Type of noise (white is default).
type	If noise==white, noise==task-related or noise==mixture, type of system noise (gaussian is default).
weights	If noise==mixture, vector of weights with 5 elements to specify the fraction of the noise components.
verbose	Logical indicating if warnings should be returned.
rho	If noise==temporal or noise==mixture, value of autocorrelation coefficients. The length of the vector indicates the order of the autoregressive model.
freq.low	If noise==low-frequency or noise==mixture, frequency of the low-frequency drift in seconds.
freq.heart	If noise==physiological or noise==mixture, frequency of heart rate in Hz.
freq.resp	If noise==physiological or noise==mixture, frequency of respiratory rate in Hz.
vee	If type=="rician", non-centrality parameter of the distribution.

Value

A vector representing the fMRI time series.

Author(s)

M. Welvaert

See Also

simVOLfmri, simprepTemporal

Examples

design <- simprepTemporal(totaltime=200, onsets=seq(1,200,40), 
	durations=20, effectsize=1, TR=2, hrf="double-gamma")
ts <- simTSfmri(design=design, SNR=1, noise="white")
## Not run: plot(ts, type="l")

NeuroStat/neuRosim documentation built on Sept. 14, 2019, 10:37 a.m.