[R] Vincentizing Reaction Time data in R

[Daniel Nordlund]

On 5/20/2015 6:22 PM, John Kane wrote:
>
>
>> -----Original Message-----
>> From: gabriel.weindel at gmail.com
>> Sent: Wed, 20 May 2015 22:31:48 +0200
>> To: jrkrideau at inbox.com, john.archie.mckown at gmail.com
>> Subject: Re: [R] Vincentizing Reaction Time data in R
>>
>> John Kane : I already read the paper and wrote an e-mail to the author,
>> he used matlab and suggested me to ask this same question on this forum.
>> But thank you for your answer.
>
> The paper said that they had used R !  They must have forgotten to add what may have been a minor bit of use of mintabl
>
> I had a look at the equation in the Wiki article and I have long ago forgotten how to read such a thing but I wonder how complicated it is as an algorithm?  R is very flexible and it might be fairly easy to just write a function to do it.
>
> Actually I just had a very quick look at the Ratcliff paper in Psychological Bulletin 1979, Vol. 86, No. 3, 446-461 (http://star.psy.ohio-state.edu/coglab/People/roger/pdf/Papers/psychbull79.pdf)
>
> I am tired and it is not my area of expertise but it does not look too difficult to write a function in R to do this. But I have been wrong before. :)
>
>>
>> John McKown : thanks a lot, this could be a great help to me but I have
>> to take a closer look.
>>
>> Again thank you for your replies.
>>
>> Regards,
>>
>> --
>> Gabriel Weindel
>> Master student in Neuropsychology - Aix-Marseille University (France)
>>
>>
>>
>> Le 20/05/2015 18:41, John Kane a écrit :
>>> John Kane
>>> Kingston ON Canada
>>>
>>>> -----Original Message-----
>>>> From: john.archie.mckown at gmail.com
>>>> Sent: Wed, 20 May 2015 09:38:47 -0500
>>>> To: gabriel.weindel at gmail.com
>>>> Subject: Re: [R] Vincentizing Reaction Time data in R
>>>>
>>>> On Wed, May 20, 2015 at 5:13 AM, Gabriel WEINDEL
>>>> <gabriel.weindel at gmail.com>
>>>> wrote:
>>>>
>>>>> Dear all,
>>>>>
>>>>> For my master thesis, I'm currently working in cognitive neuroscience
>>>>> on
>>>>> executive control through measurement of reaction time and I need to
>>>>> get
>>>>> my
>>>>> data 'vincentized' with an exclusive use of R set by my statistic
>>>>> teacher
>>>>> for a test purpose, for this reason I can't use the python code the
>>>>> lab
>>>>> team usually uses.
>>>>> Despite a dozen hours of research I couldn't find any package or
>>>>> R-code
>>>>> which would allow the use of vincentization, that's why I'm querying
>>>>> help
>>>>> on the R forum.
>>>>>
>>>>> So has anyone ever used vincentization in R ?
>>>>>
>>>>
>>>> I haven't. And I failed statistics in school. But a Google search got
>>>> me
>>>> to
>>>> this page, which I hope might be of some help to you. If not, my
>>>> apologies.
>>>>
>>>> https://stat.ethz.ch/pipermail/r-help/2003-May/034272.html
>>>> [https://stat.ethz.ch/pipermail/r-help/2003-May/034272.html]
>>> I never heard of it either and I passed a couple out of some number > 2
>>> but we always thought the perception and cognition people strange.
>>> I think this paper may be a lead. An email to the authors might help
>>> http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4017132/
>>> [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4017132/]
>>>>
>>>
>>>>> Gabriel Weindel
>>>>> Master student in Neuropsychology - Aix-Marseille University (France)
>>>


A (very) brief search regarding 'vincentizing' reaction time (RT) 
suggests that it just involves binning the RTs and computing the means 
within bins (typically deciles), then analyzing how the distribution of 
means differs across experimental conditions.  This may help you get 
started.

# create some data
rt <- rnorm(100,200,50)
# create deciles for binning
decile <- as.numeric(cut(rt, quantile(rt,0:10)/10),include.lowest=TRUE))
# collect into a dataframe (not really necessary)
df <- data.frame(rt=rt, decile=decile)
#compute the bin means
aggregate(rt,list(decile),mean,data=df)


This should give you a start,

Dan

-- 
Daniel Nordlund
Bothell, WA USA