An adjuster and response handler element that lets the subject adjust properties of other elements by key press. Also works with other keyboard-like devices. Use property deltas to assign keys to adjustment values and one key to say "done adjusting".

Response values generated are adjusted property value(s).

▸ Ends on its own?

By default yes, when it records one "done adjusting" response. You can change number of responses to wait for in property maxNumResponses. If you set maxNumResponses = <cd>inf<cd>, records responses indefinitely until a condition you set in property end.

If an element can end on its own, you don't need to set end conditions for it in property end (unless you want it to maybe end earlier).

No—runs until a condition you set in property end.

Input properties

Adjustable properties

You can vary or allow the subject to adjust the following input properties of an object of this type in real time when it's running. If you need to make other properties adjustable, you can edit the element type code—see Element Type Programming Manual.





Default: default device, usually keyboard

<cd>[]<cd> = default device according to Psychtoolbox, which is generally the keyboard. Usually this is all you need to know.

Optionally you can listen for input from some other keyboard-like device. n_device is HID device number to listen to. You can use Psychtoolbox functions GetKeyboardIndices or PsychHID('Devices') to see available device numbers. A keyAdjuster element uses Psychtoolbox KbCheck underneath and n_device goes to the input of that function. See help for these functions if you need more information on device numbers.


No default

A 2-column cell array with each row assigning a key or key combination (e.g. Shift + Left) to an adjustment value:

{column 1} key number, or vector of key numbers for a key combination. Key numbers depend on your operating system. The little tool KbShow is an easy way to find them at the MATLAB command line. See also Psychtoolbox KbName. Note this is before responses are received, so these are always key numbers, even if you use property translateResponse to record responses as other values.

{column 2} numeric value (not necessarily scalar) that is adjustment to apply when the key(s) are pressed.

Usually you also want to assign a key the subject can press to say they are done adjusting (the response). Do this using the string <cds>"r"<cds> in column 2.

Use adjust to set where and how adjustments are applied.


Default: repeatDelay = 0.5 sec
Default: repeatRate = 4 adjustments/sec

repeatDelay is delay before repeating adjustment (sec) when subject holds key(s) down.

repeatRate is adjustment repeat rate (adjustments/sec).

Input properties all visual elements have


Input properties all adjuster elements have


Input properties all objects have


Record properties

PsychBench uses record properties to record information during experiments. You can't set record properties but you can see them in experiment results by listing them input property report.