Mismatched Autidory Oddball (MMN)

Overview

Short (300 ms) sinusoidal auditory tones are presented in an oddball paradigm with the standard stimulus (300Hz tone) appearing in 85% of trials compared to the deviant stimulus (700Hz tone) appearing in 15% of trials. The stimuli are presented in a pseudorandom order where two deviants are never played one after another. Baseline videos are playing in the background at all times, which are the same videos used in the Resting-State task.

Conditions

Standard

300 ms sinusoidal tone at 300Hz

Deviant

300 ms sinusoidal tone at 700Hz

Blocks / Trials

The experiment conists of 2 blocks of 60 trials each (51 standard, 9 deviant), resulting in 120 total trials. Each trial consists of a 1-second tone stimulus and an inter-trial interval (ITI) of 700ms. Trials are presented in a pseudorandom order, such that two deviants are never played one after another.

Note

The MMN_A.dat and MMN_B.dat files contain the specification for the trial sequence.

Animations

Baseline videos

The baseline videos are the same as the Resting-State task, and are present throughout the experiment for the participant to view.

Interest Areas

There are no interest areas defined for this task.

Gaze Triggers

There are no gaze triggers defined for this task.

Classifiers

There are no tiral classifiers defined for this task.

Event Messaging

Experiment Builder will send experiment event codes to both the Eyelink and EGI acquisition systems, and the event code patterns differ slightly:

EGI acquisition

EGI Netstation does not support the same event messaging as the Eyelink Host PC, as event codes are generally restricted to 4 characters. The table below shows the corresponding event codes for the EGI Netstation acquisition, and the DIN event triggered by the photo-diode on the screen for each event.

Event Description	EGI Event		DIN
Condition	Standard	Deviant	EGI	Eyelink
Onset of tone	mmns	mmnt	DIN4	4

Note

DIN events represent the auditory rise onset of each tone, and are generated by the Cedrus Stimtracker that is connected to the speakers (audio output jack), and are used for assurance of event timing accuracy.

In addition to the event codes above, the following codes are also sent to the EGI Netstation acquisition system, but generally are not needed for offline analysis:

Description	EGI Event
begin task	VBeg
Netstation misc event	TSYN
display start menu	dstr
display break menu	dbrk
display end screen	dend