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Create a single trial regressor

single_trial_regressor.Rd

Creates a regressor object for modeling a single trial event in an fMRI experiment. This is particularly useful for trial-wise analyses where each trial needs to be modeled separately. The regressor represents the predicted BOLD response for a single event using a specified hemodynamic response function (HRF).

Usage

single_trial_regressor(
  onsets,
  hrf = HRF_SPMG1,
  duration = 0,
  amplitude = 1,
  span = 24
)

Arguments

onsets

the event onset in seconds, must be of length 1.

hrf

a hemodynamic response function, e.g. HRF_SPMG1

duration

duration of the event (default is 0), must be length 1.

amplitude

scaling vector (default is 1), must be length 1.

span

the temporal window of the impulse response function (default is 24).

Value

A `Reg` object (inheriting from `regressor` and `list`).

Details

This is a convenience wrapper around `regressor` that ensures inputs have length 1.

See also

regressor

Examples

# Create single trial regressor at 10 seconds
str1 <- single_trial_regressor(onsets = 10, hrf = HRF_SPMG1)

# Single trial with duration and custom amplitude
str2 <- single_trial_regressor(
  onsets = 15,
  duration = 3,
  amplitude = 2,
  hrf = HRF_SPMG1
)

# Evaluate the response
times <- seq(0, 40, by = 0.1)
response <- evaluate(str1, times)