In the cited paper their methodology is explained in the Materials and Methods section on p.209, where it says:
Fig. 4 shows the norm of the CoP during the experiment [...] which are represented by spikes in the norm of the CoP [...] In order to characterize the movement properties of the CoP, we have computed the corresponding spectra over the ...
The purpose of unbiased hit rate is to avoid invalid conclusions in cases where subjects indiscriminately use one (or only few) response options. To give an example (responses in rows, stimuli in columns):
Happy Sad Angry Fearful
Happy 1 0 0 1
Sad 7 8 6 5
Angry 0 0 0 0
As far as I know, short answer is no - there is no gold standard for EEG files. But EEG is a time series (amplitude) from several channels. So the most common way to represent it is columns as electrodes and rows as points of time. I think almost all software is possible to read such structure as txt file. But EEG is not only time series. Usually it is ...
Averaging psychometric curves may not be the preferred way to pool psychophysical data.
Typically, extracted gold-standard outcome measures from the psychometric curves will be pooled and averaged to perform statistical analyses and so on.
For example, in the visual sciences a much-used outcome measure is the visual acuity where, for ...
You talk about the challenge of the variability in EEG data formats --- While I am (unfortunately) not aware of a standard EEG data format, there are attempts to standardize the way that EEG data could be shared:
The Brain Imaging Data Structure (BIDS) tries to clarifying the structure of directories and meta data necessary when sharing neuro-imaging data. ...
By default your 8 levels are probably coded linearly: e.g.,
1, 2, 3, 4, 5, 6, 7, 8
-3.5,-2.5, ..., 2.5, 3.5
To examine quadratic effects you could simply square these values. Interpretation of linear and quadratic parameters will be clearer if you first center the linear variable before squaring.
So you could enter (-3.5)^2 = 12.25; (-2.5)^2 = 6.25,...
Regardless of what the chance level exactly was, as alluded to in the comments, the scores leap from 0.1 to 0.8. This results in nearly vertical slopes that are prone to convergence errors and hence lead to suboptimal threshold estimates in terms of accuracy. MATLAB always warns me when that happens. I have no experience with PsychoPy unfortunately.
If you ...
If the question is 'Will it start to rain based on this cloud cover?' and the answer is a binary 'yes' or 'no' and the subsequent question is 'How sure are you about that?', then the answer to your question
Does the confidence rating reflect their estimate of likelihood of
rain, or rather the likelihood that the choice is correct?
is the latter: it ...
This overlaps a lot with these two questions: So check them out
How to measure group differences incorporating reaction time / accuracy trade-off?
How to analyze reaction times and accuracy together?
Regarding some specifics of your question, reaction time variance will often be strongly correlated with reaction time mean. So in routine measures of ...