A few things not working properly. And flicker.

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A few things not working properly. And flicker.

A few things not working properly. And flicker.

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Blackadder	Blackadder posted 14 Years Ago HOT Topic Details Share Topic
Group: Forum Members Posts: 280, Visits: 147	Hi All, consider the attached script. There are a few things not functional here. (1) Fixation cross flickers between trials TRIAL_refset and TRIAL_probe. There is not a single "erase=true" statement in the entire script. However, the fixation cross (or text in this demo script) flickers at the switch between TRIAL_refset and TRIAL_probe. Since we are doing an EEG experiment, the flicker yields EEG activity which we'd rather avoid. (2) A second port stimulus in trial TRIAL_refset has no effect. Issue (1) could be circumvented by integrating TRIAL_refset and TRIAL_probe into one trial. The latter should look like <trial TRIAL_refset> / iscorrectresponse = [((values.iIdent==0) && (trial.TRIAL_probe.response==203))\|\|((values.iIdent==1) && (trial.TRIAL_probe.response==205))] / responseinterrupt = trial / responsetime = 2250 / responsetrial = (anyresponse, TRIAL_response) / responsetrial = (noresponse, TRIAL_response) / stimulustimes = [0 = SHAPE_blank,PIC_fix,TEXT_debugstring; 1500=PORT_refset,PIC_ref_p01,PIC_ref_p02,PIC_fix; 3000=SHAPE_blank,PIC_fix; 4500=PORT_probe,SHAPE_blank,PIC_ref_p03; 5250=SHAPE_blank] / timeout = 8250 / validresponse = (203,205,noresponse) </trial> Unfortunately, PORT_probe is not set in this case. (3) Inquisit allows only for some none-consecutive numbers in an <item>. The port triggers need to be computed at runtime since they encode some important trial properties. Since I wasn't aware of a way to send integer values to a port, I decided to realize a translation table "integer -> binary" via an item. The various integer codes used throughout the script are not consecutive, hence I originally planned to define the <item> like this: <item ITEM_portsignals> / 1 = "00000001" / 2 = "00000010" / 3 = "00000011" / 11 = "00001011" / 12 = "00001100" / 13 = "00001101" / 14 = "00001110" / 15 = "00001111" / 16 = "00010000" / 21 = "00010101" / 22 = "00010110" / 23 = "00010111" / 24 = "00011000" / 25 = "00011001" / 26 = "00011010" / 31 = "01101111" / 32 = "01110000" / 33 = "01110001" / 34 = "01110010" / 35 = "01110011" / 36 = "01110100" / 41 = "01111001" / 42 = "01111010" / 43 = "01111011" / 44 = "01111100" / 45 = "01111101" / 46 = "01111110" </item> Inquisit does not issue an error when I do so. During runtime, while the following expressions work: getitem(ITEM_portsignals,1) getitem(ITEM_portsignals,11) getitem(ITEM_portsignals,26) these do not but issue a script error: getitem(ITEM_portsignals,31) getitem(ITEM_portsignals,46) Any clues on any of these? Bye, Malte. Attachments FaceWatch_WorkMem_EEG_test.exp (928 views, 18.00 KB)
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Dave	Dave posted 14 Years Ago ANSWER Post Details Share Post
Group: Administrators Posts: 12K, Visits: 98K	(1) Fixation cross flickers between trials TRIAL_refset and TRIAL_probe. There is not a single "erase=true" statement in the entire script. However, the fixation cross (or text in this demo script) flickers at the switch between TRIAL_refset and TRIAL_probe. Since we are doing an EEG experiment, the flicker yields EEG activity which we'd rather avoid. There is no TRIAL_refset in the script you attached. Also, I'm not seeing any flickers. (2) A second port stimulus in trial TRIAL_refset has no effect. Issue (1) could be circumvented by integrating TRIAL_refset and TRIAL_probe into one trial. The latter should look like <trial TRIAL_refset> / iscorrectresponse = [((values.iIdent==0) && (trial.TRIAL_probe.response==203))\|\|((values.iIdent==1) && (trial.TRIAL_probe.response==205))] / responseinterrupt = trial / responsetime = 2250 / responsetrial = (anyresponse, TRIAL_response) / responsetrial = (noresponse, TRIAL_response) / stimulustimes = [0 = SHAPE_blank,PIC_fix,TEXT_debugstring; 1500=PORT_refset,PIC_ref_p01,PIC_ref_p02,PIC_fix; 3000=SHAPE_blank,PIC_fix; 4500=PORT_probe,SHAPE_blank,PIC_ref_p03; 5250=SHAPE_blank] / timeout = 8250 / validresponse = (203,205,noresponse) </trial> Unfortunately, PORT_probe is not set in this case. See response to (1). Offhand though, I'd say introducing a proper <port erase> before sending the second trigger could help. (3) Inquisit allows only for some none-consecutive numbers in an <item>. The port triggers need to be computed at runtime since they encode some important trial properties. Since I wasn't aware of a way to send integer values to a port, I decided to realize a translation table "integer -> binary" via an item. The various integer codes used throughout the script are not consecutive, hence I originally planned to define the <item> like this: <item ITEM_portsignals> / 1 = "00000001" / 2 = "00000010" / 3 = "00000011" / 11 = "00001011" / 12 = "00001100" / 13 = "00001101" / 14 = "00001110" / 15 = "00001111" / 16 = "00010000" / 21 = "00010101" / 22 = "00010110" / 23 = "00010111" / 24 = "00011000" / 25 = "00011001" / 26 = "00011010" / 31 = "01101111" / 32 = "01110000" / 33 = "01110001" / 34 = "01110010" / 35 = "01110011" / 36 = "01110100" / 41 = "01111001" / 42 = "01111010" / 43 = "01111011" / 44 = "01111100" / 45 = "01111101" / 46 = "01111110" </item> Inquisit does not issue an error when I do so. During runtime, while the following expressions work: getitem(ITEM_portsignals,1) getitem(ITEM_portsignals,11) getitem(ITEM_portsignals,26) these do not but issue a script error: getitem(ITEM_portsignals,31) getitem(ITEM_portsignals,46) AFAIK, the '/ 1', etc. in your <item> element doesn't actually mean anything to Inquisit's parser -- it will simply construct sequential item indexes based on the total number of item entries contained in the <item> element. This means 'getitem(ITEM_portsignals,4)' will return your '/ 11', while 'getitem(ITEM_portsignals,11)' will return your '/ 22'. The latter expressions fail because they're out of index (i.e. there is no item no. 46). Workaround: Fill in the blank spots with empty entries. Cheers, ~Dave
	Like 75
Dave	Dave posted 14 Years Ago ANSWER Post Details Share Post
Group: Administrators Posts: 12K, Visits: 98K	P.S.: BTW, you do realize that '/ erase = true' is actually the default setting, don't you? I.e. you have to explicitly declare '/ erase = false' for all your stims. ~Dave
	Like 85
Blackadder	Blackadder posted 14 Years Ago ANSWER Post Details Share Post
Group: Forum Members Posts: 280, Visits: 147	Script has been fixed, trial TRIAL_refset was erroneously named TRIAL_main.
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Blackadder	Blackadder posted 14 Years Ago ANSWER Post Details Share Post
Group: Forum Members Posts: 280, Visits: 147	Dave, you've once again been helpful. Amending all stimuli (except the <port> stimuli, of course) with /erase=false did the trick - no more flickering. I am not quite sure, however, what you mean by sending a proper <port erase> command. And for the item issue: filling the item with dummy entries was what I eventually came up with. Thank god lpt is only 8 bits. Bye, Malte.
	Like 112
Dave	Dave posted 14 Years Ago ANSWER Post Details Share Post
Group: Administrators Posts: 12K, Visits: 98K	Dave, you've once again been helpful I live to serve...;-) I am not quite sure, however, what you mean by sending a proper <port erase> command. For the case of 'PORT_Probe' not being sent out, I'd try introducing yet another port signal in between 'PORT_refset' and 'PORT_probe' which would set all bits to low again <port PORT_erase> / items = ("00000000") [...] </port> yielding something like <trial TRIAL_refset> / iscorrectresponse = [((values.iIdent==0) && (trial.TRIAL_probe.response==203))\|\|((values.iIdent==1) && (trial.TRIAL_probe.response==205))] / responseinterrupt = trial / responsetime = 2250 / responsetrial = (anyresponse, TRIAL_response) / responsetrial = (noresponse, TRIAL_response) / stimulustimes = [0 = SHAPE_blank,PIC_fix,TEXT_debugstring; 1500=PORT_refset,PIC_ref_p01,PIC_ref_p02,PIC_fix; 3000=SHAPE_blank,PIC_fix,PORT_erase; 4500=PORT_probe,SHAPE_blank,PIC_ref_p03; 5250=SHAPE_blank] / timeout = 8250 / validresponse = (203,205,noresponse) </trial> Make sense? ~Dave
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Blackadder	Blackadder posted 14 Years Ago ANSWER Post Details Share Post
Group: Forum Members Posts: 280, Visits: 147	Perfectly, I'll try that and let you know. But since this is coming from you, I have good faith [I]
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Dave	Dave posted 14 Years Ago ANSWER Post Details Share Post
Group: Administrators Posts: 12K, Visits: 98K	But since this is coming from you, I have good faith BAD mistake. Everyone knows I can't be trusted. But seriously, I'm not sure my suggestion will do the trick. Troubleshooting port issues is a major pain, IMO. ~Dave
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Dave	Dave posted 14 Years Ago ANSWER Post Details Share Post
Group: Administrators Posts: 12K, Visits: 98K	Any progress / new insights regarding the port issue? ~Dave
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Blackadder	Blackadder posted 14 Years Ago ANSWER Post Details Share Post
Group: Forum Members Posts: 280, Visits: 147	Hi Dave, not yet. I got no access to the gadget that's recording the lpt signals and the colleague who has will not be in before Monday, I'll report as soon as I know something. Let's hope the best, I'm off to Serbia until Tuesday. Bye, Malte.
	Like 82