Black Box IEEE 1284 Betriebsanweisung PDF herunterladen (Seite 49)

The Black Box Toolkit Page 49 of 98

This type of setup is illustrated by the schematic below.

In order to test the presentation and response timing of the remote PC, BBTK No 1 would

generate a 1ms wide pulse every 1993ms exactly matching a real fMRI scanner. This

pulse would be simultaneously fed into the remote PC and also into BBTK No 2.

BBTK No 2 would run DSC in response pad mode and would detect stimulus images

together with any auditory materials presented by the remote PC (as would a subject in the

real scanner). The researcher would mimic a subject and respond to either an image or

audio presented by the remote PC paradigm. Reponses would be made using the BBTK

response pad. The active switch closure lead would simultaneously close the response

device on the remote PC.

By using a setup like this we can check all aspects of the remote PC’s performance in

terms of:

• Scanner sync pulse registration

• Visual stimulus display onset, duration and offset

• Auditory stimulus onset, duration and offset

• Synchrony between visual and auditory stimulus materials

• Response time and response duration

By comparing the times with those recorded by the remote PC we can detect any timing

discrepancies. When we examine the RTL data captured by BBTK No 2 we would be able

to examine exact timing data for all events. A simulated trace is shown below.

1 2 ... 44 45 46 47 48 49 50 51 52 53 54 ... 97 98

Keine Kommentare

Black Box IEEE 1284 Betriebsanweisung Seite 49