New to E-Prime! Help with randomization of item presentation.

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Miguel Arce

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Nov 18, 2015, 6:52:42 PM11/18/15

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Hi e-prime experts,

We are new to e-prime and are trying to set up a basic choice reaction time test. An X will be presented to either the left visual field (LVF) or the right visual field (RVF). If it is presented to the RVF, then the participant will need to respond with the L key. If it is presented to the LVF, then the participant will need to respond with the A key.

We are having difficulty randomizing the visual field presentation. The following described how we have the structure set up currently.

· Experiment

o SessionProc

§ Instruction

§ BlockList

· TrialList

o JitterList

§ TrialProc

· RVF (TextDisplay)

· LVF (TextDisplay)

§ ThankYou (TextDisplay)

These are the associated properties

· SessionProc (Timeline of “Instructions” [TextDisplay], BlockList [List], and “Thank You” [TextDisplay]).

o BlockList has a weight of 1, Procedure BlockProc, PracticeMode = no

· BlockProc (Timeline of TrialList [List])

o TrialList has two conditions called Targets (RVF and LVF)

§ Both are equally weighted (Weight = 1)

§ Procedure = TrialProc

§ CorrectResponse = l and a

§ Target = RVF and LVF

§ Nested = JitterList

· Jitter List has 5 ISI’s, all weighted 1

· TrialProc (Timeline with RVF and LVF TextDisplays)

BlockList = Sequential

TrialList = Random; No Repeat After Reset = No

I have tried both yes and N/A for TrialList = Random. The stimuli are always presented RVF and then LVF.

I figure there is an InLine code to randomize this, but where would I insert that? From the documented examples and from the e-prime primer book, it is unclear.

Any help would be greatly appreciated!

Sincerely,

Victor & Miguel

MarcL

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Nov 29, 2015, 9:10:06 AM11/29/15

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I don't understand the structure of your experiment and I think there's some flaw in your thinking there, but I have limited time now so I'm skipping that part and copy some of your proposed structure for a solution I think works.

Structure would be as follows:

TrialList

TrialProcRVF

RVF (Text Display)

TrialProcLVF

LVF(Text Display)

For the example I assume you have 20 Items each.

So Trial List should look as follows:

Item 1 - 20:

Weight: 1

Nested: Nothing

Procedure: TrialProcRVF

... whatever you need ...

item 21 - 40:

Weight: 1

Nested: Nothing

Procedure: TrialProcLVF

You put the Text Displays in the respective procedures and set the list to random.