[Eeglablist] Question about time gap between stimuli in EEG experiment

[Makoto Miyakoshi]

Dear Maria,

I remember this poster.

   1. It is an empirical question how long you should wait for the brain to
   be 'settled'. It means you need to design an experiment to determine this
   parameter. In thinking about this problem, it becomes clear that what
   determines the 'baseline status' of the brain that can be confirmed in EEG.
   This is another good question, but the answer to this question may be able
   to find in literature easier than your original question.
   2. The above idea is based on an assumption that you passively wait for
   the brain to return to the 'baseline' default model. However, it should be
   also possible to use some active cognitive task as a refresher to force the
   brain to be 'settled' to one controlled state, which might be a better idea
   because you have a control. Typically, frontal lobe tasks have an effect on
   the limbic system to get disengaged from an emotional state (i.e. when you
   are heartbroken, solve the math problems and your pain in the heart is
   eased). So some short-duration high-intensity cognitive tasks, such as
   pretty difficult mental arithmetics etc., may work as a good refresher.

These are non-tested ideas, just random thoughts.

Makoto

On Wed, Apr 13, 2022 at 5:36 AM Maria Carvalho <
M.L.D.U.Carvalho at edu.salford.ac.uk> wrote:

> Hello, EEGLab community,
>
> First, I would like to wish you a Happy Easter! 🐇🌟
>
> I'm doing my PhD in soundscape at the University of Salford and a newcomer
> to brain activity studies. I have access to 5 EEG caps, and I intend to use
> them in an experiment using virtual reality and audio-visual stimuli. For
> more information, I have attached a poster presented at the 1st EEGLab
> Workshop 2021.
>
> The experiment will have 9 audio-visual stimuli with 8 seconds duration
> randomly presented 40 times each, but I still don't know how much time to
> put between stimuli for the brain to 'settle'.
>
>
>    - So, I ask you: How long do you suggest I leave between stimuli?
>    -
>
> From what I have seen in EEG papers related to sound and audio-visual
> stimuli, this gap ranges from 1 second to 20 minutes. Since I'd like to
> compare alpha and beta waves as other soundscape experiments have done, I
> am not sure about how to set up the time gap between stimuli (papers listed
> below). They used 90 seconds between one-minute (Li et al, 2021) and five
> minutes (Li, Z., & Kang, J., 2019) samples/stimuli. However, I consider a
> 90-second interval too much for an 8-second sample. What would you
> recommend?
>
> Li, Z., Ba, M., & Kang, J. (2021). Physiological indicators and subjective
> restorativeness with audio-visual interactions in urban soundscapes.
> Sustainable Cities and Society, 75, 103360.
> Li, Z., & Kang, J. (2019). Sensitivity analysis of changes in human
> physiological indicators observed in soundscapes. Landscape and Urban
> Planning, 190, 103593.
> Looking forward to your reply, I thank you in advance.
>
> Looking forward to your reply, I thank you in advance.
>
> Best wishes,
>
>
> *Maria Luiza de Ulhôa Carvalho Postgraduate Researcher  |  Acoustics
> Research Centre*
> *Sponsors** CAPES**  |  UFG*
>
> Newton Building, Room 150, University of Salford, Salford, M5 4WT
>
> mobile: +44 (0)7721 606 709
>
> e-mail: M.L.D.U.Carvalho at edu.salford.ac.uk <P.Demonte at edu.salford.ac.uk>
>
> web: https://urldefense.proofpoint.com/v2/url?u=http-3A__www.acoustics.salford.ac.uk&d=DwIFaQ&c=-35OiAkTchMrZOngvJPOeA&r=kB5f6DjXkuOQpM1bq5OFA9kKiQyNm1p6x6e36h3EglE&m=Nu3seG-XrrOL0CoefMPX03Vz_YloCfz0TiVqLl4P3BsYufyBGNCTkLbQQ6lzpcNf&s=3MaoSXOD3WkTQSIpKuuVTLCsbWSGv-8UQIJRgrFb_Fo&e= 
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>
>
> [image: 1515668337090_UniOfSalford]
>
>