You need to raise the gemwin framerate. Just create the object like this: [gemwin 50] and you should see all of the flashes. Also, setting the gemwin to the refresh rate of the display might be best.<br><br><div><span class="gmail_quote">
On 10/11/07, <b class="gmail_sendername">Batuhan Bozkurt</b> <<a href="mailto:batuhan@batuhanbozkurt.com">batuhan@batuhanbozkurt.com</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Hi,<br><br>A friend from our schools psychology department wants to use PD and GEM<br>for an experiment. Here is his question and attached is the example<br>patch. We need you help on this. Thanks.<br><br>-------------------------------------
<br><br>OK, this is the patch that I'm going to use to conduct a research on<br>cross-modal interactions in human perception. I'd be happy to fill<br>anyone in on the topic because generally human cognition is fun to poke
<br>around.<br><br>So the required stimuli are a "beep" sound (which is a 3.5khz sine with<br>7 ms duration) and a "flash" (which is basically a white circle visible<br>only for 20ms).<br><br>The problem is, it is very hard for an object to "flash" with this short
<br>duration. If you look at the patch you'll see that less than 50% of the<br>trials do not produce anything.<br><br>I have to come up with a workaround to this and I thought maybe if I can<br>syncronize the onset of the flash with the refreshing rate, I can at
<br>least make the disk visible for all of the trials. I can sacrifice the<br>precision in terms of duration but that is bound to happen I guess.<br><br>I made this patch on windows with my laptop with a poor refreshing rate
<br>and another laptop with Macosx did not perform any better on the<br>task(they are both 60hz screens). But I am guessing that a non-lcd<br>monitor may do better? Any comments or suggestions on this?<br><br>Relevant information on the stimuli and the procedure can be found in
<br>this reference article for those of you who are interested "Visual<br>illusion induced by sound" by Ladan Shamsa, Yukiyasu Kamitanib, Shinsuke<br>Shimojoa.<br><br><br><br>#N canvas 78 53 295 395 10;<br>#X obj 13 248 gemhead;
<br>#X msg 101 259 0 0 0;<br>#X obj 13 311 disk 3 40;<br>#X msg 72 173 255 255 255;<br>#X obj 72 147 bng 15 250 50 0 empty empty empty 0 -6 0 8 -262144 -1<br>-1;<br>#X text 158 232 problem number;<br>#X obj 72 200 t b l;<br>
#X obj 20 30 cnv 15 100 60 empty empty empty 20 12 0 14 -195568 -66577<br>0;<br>#N canvas 0 22 454 304 gemwin 0;<br>#X obj 132 136 gemwin;<br>#X obj 67 89 outlet;<br>#X obj 67 10 inlet;<br>#X obj 67 41 route create;<br>#X msg 67 70 set destroy;
<br>#X msg 142 68 set create;<br>#X msg 198 112 destroy;<br>#X msg 132 112 create \, 1;<br>#X connect 2 0 3 0;<br>#X connect 3 0 4 0;<br>#X connect 3 0 7 0;<br>#X connect 3 1 5 0;<br>#X connect 3 1 6 0;<br>#X connect 4 0 1 0;
<br>#X connect 5 0 1 0;<br>#X connect 6 0 0 0;<br>#X connect 7 0 0 0;<br>#X restore 25 69 pd gemwin;<br>#X msg 25 50 create;<br>#X text 21 29 Create window:;<br>#X obj 101 233 delay 20;<br>#X obj 13 284 color 0 0 0;<br>#X connect 0 0 12 0;
<br>#X connect 1 0 12 1;<br>#X connect 3 0 6 0;<br>#X connect 4 0 3 0;<br>#X connect 6 0 11 0;<br>#X connect 6 1 12 1;<br>#X connect 8 0 9 0;<br>#X connect 9 0 8 0;<br>#X connect 11 0 1 0;<br>#X connect 12 0 2 0;<br><br>_______________________________________________
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</blockquote></div><br>