Millisecond Forums

Hi guys,

I've created a slider stimulus for a Visual Analogue scale that I want to implement in a couple of fMRI studies. The issue I have is that I will need to employ a Cedrus Response Box (fantastic troubleshoot page incidentally, if other users are interested http://www.millisecond.com/support/docs/v4/html/howto/cedrusresponse.htm), and in doing so I am unsure how to use the response box buttons to shift the slider arrow back and forth along the x-axis line as is usually carried out by the keyboard. 

The current code has a single <slider> stimulus per <surveypage> displaying a range of 0-100, and participants use the keyboard to shift the slider arrow in the position they require; after a 10000ms timeout the response is recorded for the last position of the slider arrow.

Is there any possibility of having the response box keys similarly emulate the left and right keyboard arrow keys  in the <slider> stimulus? If not, is there another way around this? I've seen your code for a VAS using the <trial> element rather than the <slider> stimulus but I'm not quite sure how to imitate the shifting of the arrow.

Any help at all would be excellent - you are always a huge help! I've added the <slider> code below that I am using (with the keyboard).

Thanks,
Warren

______

<defaults>
/ screencolor = white
/ fontstyle = ("Arial", 5%, true, false, false, false, 5, 0)
/ txcolor = black
/ inputdevice = mouse
</defaults>

<data>
/ separatefiles = true
/ columns = [date, time, group, subject, trialcode, blockcode, blocknum, trialnum, latency, response,
correct, stimulusnumber, stimulusitem, values.trialcurrenttime, values.trialelapsedtime ]
</data>

<summarydata>
/file = "ANT_task_summary.iqdat"
/columns = [script.startdate, script.starttime, script.subjectid,
]
</summarydata>
--------------------------------------------
****STIMULI****
--------------------------------------------

<text captioncrave>
/items = ("How severe is your craving for alcohol RIGHT NOW")
/ height = 40%
</text>

<text captionanxiety>
/items = ("How severe is your anxiety RIGHT NOW")
/ height = 40%
</text>

<text labelnocrave>
/items = ("No craving")
/fontstyle = ("arial", 36, false, false, false, false, 5)
/ hposition = 12%
/ vposition = 53%
/ hjustify = center
</text>

<text labelhighcrave>
/items = ("Very severe craving")
/ fontstyle = ("arial", 36, false, false, false, false, 5)
/ hposition = 88%
/ vposition = 53%
/ hjustify = center
</text>

<text labelnoanxiety>
/items = ("No anxiety")
/fontstyle = ("arial", 36, false, false, false, false, 5)
/ hposition = 12%
/ vposition = 53%
/ hjustify = center
</text>

<text labelhighanxiety>
/items = ("Very severe anxiety")
/ fontstyle = ("arial", 36, false, false, false, false, 5)
/ hposition = 88%
/ vposition = 53%
/ hjustify = center
</text>


<slider VAScrave>
/ range = (1, 100)
/ position = (15%,50%)
/ slidersize = (60, 5%)
/ showtooltips = false

</slider>

<slider VASanxiety>
/ range = (1, 100)
/ position = (15%,50%)
/ slidersize = (60, 5%)
/ showtooltips = false

</slider>

<clock timer>
/ mode = timer
/ resetrate = trial
/ txcolor = black
/ txbgcolor = white
/ timeout = 10000
/ position = (50%, 80%)
/ format = "s"
</clock>


--------------------------------------------
****TRIALS****
--------------------------------------------

<values>

/ trialcurrenttime = 0
/trialelapsedtime = 0

</values>

<surveypage VAScravepage>
/ fontstyle = ("Verdana", -16, true, false, false, false, 5, 0)
/ stimulusframes = [1=captioncrave, timer, labelnocrave, labelhighcrave]
/ questions = [1=Vascrave]
/timeout = 10000
/ontrialbegin = [values.trialcurrenttime = script.currenttime]
/ontrialend = [values.trialelapsedtime = script.elapsedtime]

</surveypage>

<surveypage VASanxietypage>
/ fontstyle = ("Verdana", -16, true, false, false, false, 5, 0)
/ stimulusframes = [1=captionanxiety, timer, labelnoanxiety, labelhighanxiety]
/ questions = [1=Vasanxiety]
/timeout = 10000
/ontrialbegin = [values.trialcurrenttime = script.currenttime]
/ontrialend = [values.trialelapsedtime = script.elapsedtime]


</surveypage>

--------------------------------------------
****BLOCKS****
--------------------------------------------



<block posblock>
/ trials = [1=vasanxietypage; 2=vascravepage]
</block>


<expt>
/ blocks = [1-30=posblock]

</expt>