object HRF#

Specification of a hemodynamic response function (HRF) model.

Most design matrix constructors permit sparse events of the form (onset, duration, amplitude) to be convolved by a named HRF, possibly with some parameters. Some may permit dense time series to be convolved as well.

This specification makes no attempt to constrain the names and parameters, or require consistency of accepted model names across implementations. Implementations SHOULD fail if the model is unknown.


The “canonical” HRF defined in SPM:

  "Variables": ["condition1", "condition2"],
  "Model": "spm"
  • extra: Extra = Extra.forbid

field Variables: List[str] [Required]#

Name of the variables to be convolved.

These must appear in Model.X.

field Model: str [Required]#

Name of a hemodynamic model.

Known model names include:

  • "spm"

  • "spm + derivative"

  • "spm + derivative + dispersion"

  • "glover"

  • "glover + derivative"

  • "glover + derivative + dispersion"

  • "afni"

  • "fir"

The list of supported models is expandable and limited by the estimator, not the specification. Note that "glover" is the default “Gamma” HRF in FSL.

field Parameters: Optional[Dict[str, Any]]#

Parameters to the hemodynamic model.

Options will be software specific and are not controlled. For "fir", the parameter "fir_delays" is required.