Search found 9 matches

by PeterLiu
14 Aug 2012, 14:51
Forum: BCI Systems - User Applications
Topic: very irregular block duration
Replies: 7
Views: 4623

Re: very irregular block duration

Dear Juergen We wrote a standalone program to receive packages from neuroscan Acquire directly and monitor the interval between the arrival of two packages, here is the result: http://s9.postimage.org/k86ue7t33/irregular_Timing.jpg No software other than Neuroscan acquire is running. The average int...
by PeterLiu
26 Jun 2012, 17:38
Forum: BCI Systems - User Applications
Topic: very irregular block duration
Replies: 7
Views: 4623

Re: very irregular block duration

Thanks for the reply Juergen I tried our setup on another PC (still XP). and the result is as follows: http://s13.postimage.org/fmgf8tthj/timing_1.png It seems like the block duration first dropped to near zeros. I figure that it might be Neuroscan Acquire sent two data packages in that 40ms block i...
by PeterLiu
25 Jun 2012, 13:30
Forum: BCI Systems - User Applications
Topic: very irregular block duration
Replies: 7
Views: 4623

Re: very irregular block duration

Dear Juergen, Thank you for your suggestions. We were running both Neuroscan and BCI2000 on the same machine. On the other hand, it seems like we can not change Neuroscan's software packet buffer size (for making sure, we have contact Neuroscan and are waiting for response). And the NeruoscanAccess ...
by PeterLiu
22 Jun 2012, 17:21
Forum: BCI Systems - User Applications
Topic: very irregular block duration
Replies: 7
Views: 4623

very irregular block duration

Hi, During our experiment for P3speller, the block duration appears to be very irregular: http://s15.postimage.org/gfyv2wcl7/timing.jpg Our setup is: Neuroscan 4.5 Samplingrate: 1000Hz SampleBlockSize: 40 (250Hz/10 is also tried, with similar results) modules: Neuroscanclient, P3signalprocessing, P3...
by PeterLiu
13 Jun 2012, 10:24
Forum: BCI Systems - User Applications
Topic: larget latency for P300
Replies: 2
Views: 2325

Re: larget latency for P300

This explains, Thanks a lot!
by PeterLiu
12 Jun 2012, 18:51
Forum: BCI Systems - User Applications
Topic: larget latency for P300
Replies: 2
Views: 2325

larget latency for P300

Hi, We're doing research on P300-based BCI with BCI2000 and we found that the latency of the peak is around 600ms after stimulus onset. We collected data from 12 subjects, the latency were all similar (around 600ms). We used Neuroscan 4.5 for data acquisition. For the 12 subjects, the application is...
by PeterLiu
14 Nov 2011, 20:26
Forum: BCI Systems - Signal Processing
Topic: FieldTripBuffer and P3Speller
Replies: 3
Views: 3557

Re: FieldTripBuffer and P3Speller

Dear Juergen, Thank you for your last reply. I've been trying to make it work from time to time during the last few weeks but still have no luck. Currently, I encountered the following two problems: 1. The P3 speller keeps spelling letter "A" but not the ones I specified in my test code. I used the ...
by PeterLiu
11 Nov 2011, 23:09
Forum: BCI Systems - User Applications
Topic: Directly sent selected target to P3 speller
Replies: 3
Views: 2622

Directly sent selected target to P3 speller

Hi all, I wonder if there is a way to sent the selected target to P3 speller directly instead of sending stimulusCodeRes and Classification score (signal processing module is fieldtrip buffer, matlab). We want to implement our own decision making part. Also, I need the P3 speller to stop and begin n...
by PeterLiu
20 Oct 2011, 22:03
Forum: BCI Systems - Signal Processing
Topic: FieldTripBuffer and P3Speller
Replies: 3
Views: 3557

FieldTripBuffer and P3Speller

Hi, I'm new to BCI2000. I'm currently trying to use FieldTripBuffer (run in matlab) as the Signal Processing module for P3Speller application. I have managed to read the raw signal and states such as StimulusCode in matlab. However, I have trouble find a way to sent the classification result to the ...