pretrialsignal attribute

The pretrialsignal attribute specifies that before running a trial, Inquisit should wait for a signal from an external device.

Member of

Syntax

/ pretrialsignal = (modality, signal)

/ pretrialsignal = (mouse, stimulusname)

/ pretrialsignal = (mouse, mouseevent)

Parameters

modality

One of the following values:

Value	Description
keyboard	The signal is defined as a key-press on the computer’s keyboard.
mouse	The signal is defined as a mouse event on the computer’s mouse or touch screen.
com<n>	The signal is defined a serial port signal, where n specifies the port number (e.g., COM1, COM2, COM3, ...).
xid<n>	The signal is defined as a XID protocol signal from a Cedrus Response Box on the serial port, where n specifies the port number (e.g., XID1, XID2, XID3, ...).
lpt<n>	The signal is defined as a parallel port signal, where n specifies the port number (e.g., LPT1, LPT2, LPT3, ...).

signal

An integer representing the numeric signal to wait for. If the modality is keyboard, this is the scancode of the key.

mouseevent

Any of the following mouse events.

stimulusname

The name of a visual stimulus element defined elsewhere in the script.

Remarks

This is useful for requiring a confirmation response from subjects before starting a trial, or for synchronizing Inquisit with an external device such as an EEG.

Examples

The following trial waits for a parallel port signal of value 1 sent from an fMRI imaging system before starting the trial:

<trial target>
/ stimulusframes = [1=facepicture]
/ validresponse = (57)
/ pretrialsignal = (LPT1, 1)
</trial>

The following trial requires the subject to press the spacebar to start the trial:

<trial mytrial>
/ stimulusframes = [1=sometext]
/ validresponse = (57)
/ pretrialsignal = (keyboard, 57)
</trial>