A response handler element that records subject response by button press on a Cedrus response pad. At default waits for one press of any button, then records response and ends on its own.

Response values generated are button numbers (1–8). Response times are measured by the pad.

You can also use cedrusPress elements to listen for synchronization signals from an external device like a scanner. To do this set registerTrigger = <cd>true<cd> to register inputs as triggers instead of responses from subject. Most commonly then set syncExperiment = <cd>true<cd> to tell the element to synchronize the experiment at trigger. You can then set the timing of any element in the trial (element properties start/end field t_sync) and/or subsequent trial timing (trial object property start field t_sync) from sync.

If you want to set options for the pad, you can use pb_prefs → "Other" tab. Or to set for only the current experiment, you can add an object of type cedrusPad and set its properties. Typically you don't need to.

Note according to Psychtoolbox documentation, opening a Cedrus pad might be unreliable. If you get an error, it might help to just retry. You can also try reducing the baud rate by setting cedrusPad object property fullBaud = <cd>false<cd>. See http://psychtoolbox.org/docs/CedrusResponseBox.

▸ Object ends on its own?

By default yes, when it records one 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.

"Ends on its own" means ends automatically at that point. 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 any condition you set in property end.

Input properties

Adjustable properties

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

Adjustable properties

Adjustable properties





Default: set port name at the Cedrus pad

A string that is name of the serial port the pad is attached to, as accepted by Psychtoolbox IOPort('OpenSerialPort'). From Psychtoolbox documentation: On Windows this could be, e.g. <cds>"COM1"<cds>, <cds>"COM2"<cds>, etc.; on Mac it is a path to a BSD device file, e.g. <cds>"/dev/cu.usbserial-FT3Z95V5"<cds> for a serial-over-USB device with unique ID FT3Z95V5; on Linux e.g. <cds>"/dev/ttyS0"<cds> for the first real serial port, <cds>"/dev/ttyUSB0"<cds> for the first serial-over-USB device, etc.

If you leave this property at default, set port name at the pad itself instead: Add a cedrusPad object and set its property portName. You could do this if it's more convenient than setting port name in every cedrusPress element. You can also set other options for the pad at the cedrusPad object. (This default doesn't work if you have more than one Cedrus pad in the experiment.)


Default: listen to all buttons

A row vector of button numbers to listen to (1–8). <cd>[]<cd> = all.

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 using input property report.