A response handler element that shows a slider that the subject can click and drag with the mouse to select a value within a numeric range—for example, a Likert scale. One mouse button drags, and clicking any other mouse button records a response. Or optionally the subject can click a "Done" button on screen to record a response. Response value generated is a number that is the current value in the slider's range. You can use any range, discrete or continuous (properties range and increment). The element shows a readout of the current value as the subject uses the slider, either the number or from custom labels you can set. By default it also shows a title expressing the range of the slider. Note a mouseSlider element automatically shows in front of all other elements.

If an element will end automatically, you don't need to set an end time or condition in property end. However, you can if you want to add other end conditions that could occur earlier.

range
increment

Defaults: 1–7 in steps of 1

These properties set the range of numbers the slider passes through. range is a 1×2 vector [a b] setting minimum value a and maximum value b. increment is step size between a and b for values in between (typically 1). Note slider values don't have to be positive or integer. You can also set increment = 0 for a continuous slider.

You can assign custom labels to slider values for purposes of the readout—see labels below.

val1

Default: middle of range

You can change initial value for the slider here. This is a number in the range which you can set in range above. The number is rounded to the nearest increment, set in increment above.

lineLength
lineWidth
lineColor

Default: lineLength = 10 deg
Default: lineWidth = 0.1 deg
Default: lineColor = gray 50%

You can customize the appearance of the slider line with these properties. Length and width are numbers in deg. Color is a 1×3 RGB or 1×4 RGBA vector with numbers between 0–1. The slider line is always centered at element position, which you can set in property position (default window center).

sliderSize
sliderColor

Default: sliderSize = 0.8 deg
Default: sliderColor = white

You can customize the appearance of the slider button with these properties. sliderSize is circle diameter (deg). sliderColor is a 1×3 RGB or 1×4 RGBA vector with numbers between 0–1.

showTitle
title
titleFontSize
titleColor
titlePosition

Default: showTitle = yes
Default: title = range span, or label span if labels set below
Default: titleFontSize = 0.7 deg
Default: titleColor = white
Default: titlePosition = <cd>[0 -2]<cd> → 2 deg above slider, centered

showTitle = <cd>true<cd>/<cd>false<cd>: show a title. If = <cd>true<cd>:

title is a string that is title to show. Default is to show text representing the slider value range (e.g. <cds>"1 – 7"<cds>), or the label range if you set labels below (e.g. <cds>"Strongly disagree – Strongly agree"<cds>).

titleFontSize is title font height (deg). Specifically it sets height of the "em box" for the font. Typically upper case characters are a little smaller than this. If you need more information, see Wikipedia https://en.wikipedia.org/wiki/Point_(typography) for a starting point.

titleColor is a 1×3 RGB or 1×4 RGBA vector with numbers between 0–1.

titlePosition is a 1×2 vector [x y] (deg), + = right/down, that is center of the title relative to center of the slider. The slider in turn is centered at element position, which you can set in property position (default window center).

labels
roundReadoutTo
readoutFontSize
readoutColor
readoutPosition

Default: labels = no custom labels, readout = current numeric slider value
Default: roundReadoutTo = if increment = 0 (continuous slider) round to 1 decimal place, else round to integer
Default: readoutFontSize = 0.5 deg
Default: readoutColor = white
Default: readoutPosition = <cd>[0 2]<cd> → 2 deg below slider, centered

These properties let you customize the readout of the current slider value:

labels allows you to set custom labels to show for the slider values. This can be a vector of numbers for custom numbers. It can also be an array of strings for custom text labels. Either way length of the array must correspond to number of slider values according to range and increment above. labels is optional—if you don't set it, the readout shows the current numeric slider value. Or for a continuous slider (increment = 0 above) the readout always shows numeric slider values and labels is ignored. Note labels only affects the readout—response value generated is always the current numeric slider value.

roundReadoutTo is number of decimal places to round numbers in the readout to. Ignored if you set labels.

readoutFontSize is readout font height (deg). Specifically it sets height of the "em box" for the font. Typically upper case characters are a little smaller than this. If you need more information, see Wikipedia https://en.wikipedia.org/wiki/Point_(typography) for a starting point.

readoutColor is a 1×3 RGB or 1×4 RGBA vector with numbers between 0–1.

readoutPosition is a 1×2 vector [x y] (deg), + = right/down, that is center of the readout relative to center of the slider. The slider in turn is centered at element position, which you can set in property position (default window center).

showButton
buttonText
buttonFontSize
buttonTextColor
buttonColor
buttonPosition

Default: showButton = no
Default: buttonText = <cds>"Done"<cds>
Default: buttonFontSize = 0.5 deg
Default: buttonTextColor = white
Default: buttonColor = blue (RGB [32 88 161]/255)
Default: buttonPosition = <cd>[0 4]<cd> → 4 deg below slider, centered

showButton = <cd>true<cd>/<cd>false<cd>: show a "Done" button which the subject clicks on to record response = current slider value. If = <cd>false<cd> one mouse button drags the slider and clicking any other mouse button records done (see n_dragButton below). If = <cd>true<cd> all mouse buttons can drag the slider and/or click the done button, and you can use further properties to customize the button:

buttonText is a string that is text for the button.

buttonFontSize is button text font height (deg). Specifically it sets height of the "em box" for the font. Typically upper case characters are a little smaller than this. If you need more information, see Wikipedia https://en.wikipedia.org/wiki/Point_(typography) for a starting point.

buttonTextColor is a 1×3 RGB or 1×4 RGBA vector with numbers between 0–1.

buttonColor is same but for color of the button itself.

buttonPosition is a 1×2 vector [x y] (deg), + = right/down, that is center of the button relative to center of the slider. The slider in turn is centered at element position, which you can set in property position (default window center).

fontName

Default: Arial

A string setting font for title, readout, and/or Done button. See Psychtoolbox Screen('TextFont') for more information on font names.

n_dragButton

Default: mouse button 1 drags, all other buttons record response

If showbutton above = <cd>false<cd>, this is a number or vector that is mouse button number(s) to click to drag the slider. For all other buttons a click means record response = current slider value. If showButton = <cd>true<cd> then all mouse buttons work the same.

(None)