[FieldTrip] Difference in trial number per condition

[Diego Lozano-Soldevilla]

Hi Zsolt,
To complement Stan's suggestions, in case of power differences between
conditions, you could use ft_stratify:
http://www.fieldtriptoolbox.org/example/stratify
best,
Diego



On 17 June 2016 at 10:51, Pelt, S. van (Stan) <stan.vanpelt at donders.ru.nl>
wrote:

> Hi Zsolt,
>
>
>
> The amount to which this may be a concern will depend on the measures you
> want to compare. Also, the risk of drawing incorrect (qualitative)
> conclusions will of course mainly be large around your statistical
> threshold value (e.g. p=0.05). Power differences might become biased if
> groups have unequal size, power begin a squared value. See for a suggested
> numerical correction method for this, when comparing power spectra or e.g.
> Bokil et al., 2007 (http://www.ncbi.nlm.nih.gov/pubmed/16945422), but I
> assume there are also other solutions going around.
>
>
>
> Best,
>
> Stan
>
>
>
> *From:* fieldtrip-bounces at science.ru.nl [mailto:
> fieldtrip-bounces at science.ru.nl] *On Behalf Of *Zsolt Turi
> *Sent:* vrijdag 17 juni 2016 9:32
> *To:* FieldTrip discussion list
> *Subject:* [FieldTrip] Difference in trial number per condition
>
>
>
> Hi,
>
>
>
> I was wondering if FieldTrip has an optimized solution for such situations
> when the amount of trials in one condition markedly differs from the number
> of trials in the other (e.g., the ratio is 1:3 or 1:4).
>
>
>
> On the website I have found that this issue was already discussed,
> however, it is not clear to me whether this was indeed addressed by a
> FieldTrip function. Below is the link about the question I was referring
> to:
>
>
>
>
> http://www.fieldtriptoolbox.org/faq/how_does_a_difference_in_trial_numbers_per_condition_affect_my_statistical_test
>
>
>
> In case there is no such a function, could someone provide me a rough
> procedure that is methodologically acceptable in the scientific community
> to compensate for this issue?
>
>
>
> I am interested both in conceptual and implementational aspects. I would
> like to compare TFR or WPLI measures between two conditions and use
> non-parametric cluster-based permutation test for statistical analysis. My
> data is characterized by a within-subjects design, in case this is relevant
> information.
>
>
>
> Thanks for your input in advance,
>
> Zsolt
>
>
>
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