expyfun.stimuli.TrackerMHW

class expyfun.stimuli.TrackerMHW(callback, x_min, x_max, base_step=5, factor_down=2, factor_up_nr=4, start_value=40, n_up_stop=2, repeat_limit='reversals')

Up-down adaptive tracker for the modified Hughson-Westlake Procedure

This class implements a standard up-down adaptive tracker object. It is configured to run a fixed-step m*base-down n*base-up tracker (staircase), with a different z*base-up if there is “no response” to the start_value.

Parameters:

callbackcallable | ExperimentController | None

The function that will be used to print the data, usually to the experiment .tab file. It should follow the prototype of ExperimentController.write_data_line. If an instance of ExperimentController is given, then it will take that object’s write_data_line function. If None is given, then it will not write the data anywhere.

x_minfloat

The minimum value that the tracker level (x) is allowed to take. A value must be provided and cannot be “None”.

x_maxfloat

The maximum value that the tracker level (x) is allowed to take. A value must be provided and cannot be “None”.

base_stepfloat

The size of the base step when the tracker moves up or down.

factor_downfloat

The factor multiplier of the base step when the tracker moves down. The default is 2.

factor_up_nrfloat

The factor multiplier of the base step when there is “no response” (i.e., “incorrect” response) to the start_value. The default is 4.

start_valuefloat

The starting level of the tracker.

n_up_stopint

The number of times the level has a correct response in order to stop.

repeat_limitstr

How to treat trials that try to exceed either x_min or x_max. reversals will consider these trials as reversals while staying at the same level. ignore does not consider these trials as reversals.

Returns:

trackerinstance of TrackerMHW

The up-down modified Hughson-Westlake tracker object.

Notes

In the modified Hughson-Westlake procedure, the up-step is the base-step, (e.g., 5) and the down-step is 2 * base-step (e.g., 10), except when there is “no response” to the starting value. Then the up-step is 4 * base-step (e.g., 20) in order to quickly get within a suitable range for audibility and finding threshold.

check_valid(n_reversals)

If last reversals contain reversals exceeding x_min or x_max.

Parameters:

n_reversalsint

Number of reversals (starting from the end to check).

Returns:

validbool

True if none of the reversals are at x_min or x_max and False otherwise.

property n_reversals

The number of reversals so far

property n_trials

The number of trials so far

plot(ax=None, threshold=True)

Plot the adaptive track.

Parameters:

axAxesSubplot | None

The axes to make the plot on. If None defaults to current axes.

thresholdbool

Whether to plot the estimated threshold on the axes. Default is True.

Returns:

figFigure

The figure handle.

axAxesSubplot

The axes handle.

lineslist of Line2D

The handles to the staircase line and the reversal dots.

plot_thresh(ax=None)

Plot a line showing the threshold.

Parameters:

axAxes

The handle to the axes object. If None, the current axes will be used.

Returns:

linelist Line2D

The handle to the threshold line, as returned from plt.plot.

respond(correct)

Update the tracker based on the last response.

Parameters:

correctboolean

Was the most recent subject response correct?

property responses

The response history

property reversal_inds

The trial indices which had reversals

property reversals

The reversal history (0 where there was no reversal)

property stopped

Has the tracker stopped

property threshold_reached

Which levels have threshold reached

property x

The staircase

property x_current

The current level

Examples using expyfun.stimuli.TrackerMHW

Do an adaptive track staircase with MHW procedure

Do an adaptive track staircase with MHW procedure