Millisecond Forums

Hi Lucy,

Inquisit's default data recording scheme is described in the documentation (http://www.millisecond.com/support/docs/v2/html/language/datarecording.htm; for details on each column see http://www.millisecond.com/support/docs/v2/html/language/attributes/columns.htm).

A few additional comments on my part:

Participant's reaction times are contained in the data file's 'latency' column. However, as I mentioned earlier, you should double-check if your <trial> elements start recording those reaction times at the right moment (-> my previous bit about the '/ responsetime' attribute), i.e. at the same time the dots appear (2000ms, if I remember correctly).

The key pressed is recorded in the 'response' column. However, note that Inquisit does not record the "literal" key value (a or l), but the corresponding keyboard scancode (http://www.millisecond.com/support/docs/v2/html/language/scancodes.htm). The 'correct' column would usually indicate whether the given response was correct, however you need to define the '/ correctresponse' attribute in your <trial> elements for this to work (otherwise Inquisit can't know which of the available, "valid" responses is to be scored as correct).

Regards,

~Dave

Hi Dave,

Thanks for your help. Think I've done it now (well it appears to be working - no red lines when I try and run anymore!)

Having a bit of trouble with the output though. I've attached it with some queries.

I need to see the participants reaction times from when the dot appeared to when they gave a response. I also need to see if they gave the correct response (a or l). There are a lot of columns that I am unsure about so was hoping you could help me narrow it down to just get the information that I need.

Thanks,

Lucy.

Using one <block> is perfectly fine.

By default, Inquisit will start "listening" for responses only when the complete stimulus sequence as defined by '/ stimulustimes' or '/ stimulusframes' has been completed. In the example from my previous post, that would be 2500 ms into the trial (i.e. after the dots have been erased / overwritten). However, you probably want your subjects to be able to respond earlier (e.g. as soon as the dots appear at 2000 ms). The '/ responsetime' attribute allows you to do this.

Reciting from a previous response: In your design, you manipulates certain stimulus properties (gender of face -- male v. female, type of facial expressions -- compassionate v. critical, face screen position -- left  v. right, dottype -- : v. ., dot position -- left v. right, maybe more). This yields the following combiantions (may not be exhaustive):

male-critical(left)-compassionate(right)-:(left)-..(right)
male-critical(left)-compassionate(right)-:(right)-..(left)
male-critical(right)-compassionate(left)-:(left)-..(right)
male-critical(right)-compassionate(left)-:(right)-..(left)

female-critical(left)-compassionate(right)-:(left)-..(right)
female-critical(left)-compassionate(right)-:(right)-..(left)
female-critical(right)-compassionate(left)-:(left)-..(right)
female-critical(right)-compassionate(left)-:(right)-..(left)

Given your limited experience (no offense, as you know...), I think you should simply set up a separate <trial> element for each single combination (let's call 'em t1 to t8 for brevity's sake) and then sample these in equal proportions at the <block> level

<block myblock>
/ trials = [1-32=noreplace(t1,t2,t3,t4,t5,t6,t7,t8)]
[...]
</block>

which would result in each trialtype being run 4 times (8 x 4 = 32). Forgive me if there's something I'm not catching.

~Dave

Hi Dave,

Don't worry no offence taken! I don't really understand the different blocks/elements so thats why I just did it in one block. I prefer being taught things in 'real life' which is why i asked sean if there are any courses available for this. But unfortunately I think all learning has to be done online! In the end I found someone at the local university who had set up a similar experiment to me and went to see her and used her way of doing things (one block).

I'm happy to change if you think will work better though.

What does the responsetime attribute bit mean?

and don't understand this:

Depends on how you've set up the <text> elements containing the dots and the respective <trial> elements. It's really important to map such stuff out before doing any coding (no offense intended). To me it seems like you have a whole bunch of factors (gender, facetype, face position, dottype, dotposition, etc.) you'd like have balanced (i.e. each possible combination of factors should appear equally often). As stated from the get-go, the easiest way to do this is to set up a separate <trial> element for each of these combinations (there may be a lot!), and then sample from these trials in equal proportions at the <block> level. This certainly isn't the only way to do it, though. However, all other approaches would probably require a little more experience with Inquisit / how Inquisit works (again, no offense intended).

Could you give me an example please?

Thanks

Lucy.

Depends on how you've set up the <text> elements containing the dots and the respective <trial> elements. It's really important to map such stuff out before doing any coding (no offense intended). To me it seems like you have a whole bunch of factors (gender, facetype, face position, dottype, dotposition, etc.) you'd like have balanced (i.e. each possible combination of factors should appear equally often). As stated from the get-go, the easiest way to do this is to set up a separate <trial> element for each of these combinations (there may be a lot!), and then sample from these trials in equal proportions at the <block> level. This certainly isn't the only way to do it, though. However, all other approaches would probably require a little more experience with Inquisit / how Inquisit works (again, no offense intended).

When you run the experiment, a file with the *.dat extension should be created in the same folder your experiment files reside in.

Then you'll have to overwrite them with another stimulus (e.g. the rectangle stims) at some specified time (-> via stimulustimes), e.g.

/ stimulustimes = [1=focuspoint; 500=rectangle_pic;
1000=f1compassionleft_pic,f1neutralright_pic; 1500=rectangleright_pic,rectangleleft_pic; 2000=noreplace(target1left,target1right,target2left,target2right); 2500=rectangleright_pic,rectangleleft_pic]

Also give the '/ responsetime' attribute a proper look to make sure Inquisit starts registering responses at the right time.

~Dave

Hi Dave,

Thanks I've done that now and it appears to be coming on left and right, sometimes : and sometimes .. which is great.

Is there any way to control how many times each dot appears? E.g. I want half the time it to be a : and half the time a .. And half of the time to be over a compassionate face and the other half over the neutral/critical...

Where is the results output when the game is completed? Will I be able to see in which trials the : replaced the compassionate face and which ones it replaced the neutral/critical face for example.

(I need to be able to look at reaction times to see which face the participant was looking at)

Also I need the dots to flash up fpr and then disappear. At the moment they stay on the screen until the participant has responded.

Thanks for all your help,

Lucy.

Not randomly. For that you'll have to go for something like

2000=noreplace(target1left, target1right, target2left, target2right)

i.e. random without replacement

or

2000=replace(target1left, target1right, target2left,
target2right)

i.e. random with replacement

~Dave

Thanks Dave, so if i separate with commas instead will it randomly choose one of the 4 target options for each trial?

One thing that hits me right away:

<trial f1complneutralr>
    / pretrialpause = 500
    / stimulustimes = [1= focuspoint; 500 = rectangle_pic; 1000=f1compassionleft_pic,f1neutralright_pic; 1500 = rectangleright_pic, rectangleleft_pic; 2000 = target1left; target1right; target2left; target2right]
    / inputdevice = keyboard
    / validresponse = ("a", "l")
    / posttrialpause = 180
</trial>

You'll want to separate the highlighted entries with a comma (','), not a semicolon (';'). The erroneously used semicolon will lead to only 'target1left' being parsed. This applies to all your <trial> elements, the above is just one example. Let me know if this fixes your issues.

~Dave

and here is the picture stimuli and trials documents