StairHandler

data StairHandler

A Trial Handler that implements the Quest algorithm for quick measurement of psychophysical thresholds. QuestHandler relies on the jsQuest library, a port of Prof Dennis Pelli's QUEST algorithm by Daiichiro Kuroki.

Constructor

new StairHandler(options)

Source:
Parameters:
Name Type Description
options Object

the handler options

Properties
Name Type Attributes Default Description
psychoJS module:core.PsychoJS

the PsychoJS instance
varName string

the name of the variable / intensity / contrast / threshold manipulated by QUEST
startVal number

initial guess for the threshold
minVal number

minimum value for the threshold
maxVal number

maximum value for the threshold
nTrials number

maximum number of trials
name string

name of the handler
autoLog boolean <optional>
 false

whether or not to log

Extends

  • TrialHandler

Members

(static, readonly) Direction :Symbol

Source:
Properties:
Name Type Description
START Symbol
UP Symbol
DOWN Symbol

StairHandler step direction.

Type:
  • Symbol

(static, readonly) StepType :Symbol

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Properties:
Name Type Description
DB Symbol
LINEAR Symbol
LOG Symbol

StairHandler step type

Type:
  • Symbol

intensity

Source:

Get the current value of the variable / contrast / threshold.

This is the getter associated to getStairValue.

Methods

(protected) _decreaseValue()

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Decrease the current value of the variable / contrast / threshold.

(protected) _estimateStairValue()

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Estimate the next value, based on the current value, the counter of correct responses, and the current staircase direction.

(protected) _increaseValue()

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Increase the current value of the variable / contrast / threshold.

(protected) _updateTrialList()

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Update the next undefined trial in the trial list, and the associated snapshot.

addResponse()

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Add a response and advance the staircase.

getStairValue() → {number}

Source:

Get the current value of the variable / contrast / threshold.

Returns:

the current value

Type
number