prob_cueing_eeg/Nan_ssvep

%%%%%%%% Ask for help %%%%%%%%

My task is to analyze five-minute ssvep datasets that has been preprocessed and epochs (more dataset details please see below) to see if we have established SSVEP response at the expected frequencies (i.e., 17.14hz, 20hz, 24hz, 30hz) should have the peak value, as the literature 'Steady-state visually evoked potentials and feature-based attention: Preregistered null results and a focused review of methodological considerations' did in Figure 2, the literature is in folder './Project update_Presntations'.

I have tried to analyzed these datasets, the results seemed we are missing some peaks at the expected frequency-bands. So I need to ask for help, how to correctly analyze the spectrum frequency of the datasets.

The following are brief introductions to all files, and if you have any questions, please feel free to contact me.



%%%%%%%% Experiment Overview %%%%%%%%

In experiment 1: an orientation-defined (same-dimension) distractor occurred more often (90%) in one display region. Please run the main program 'searchProb.m'
In experiment 2: a luminance-defined (different-dimension) distractor occurred more often (90%) in one display region. Please run the main program 'searchProb.m'

% more details please check the presentation: '/Users/qiunan/Desktop/Study2/Data analysis and results/SSVEP analysis_5mins post /Project update_Presntations/Study2 SSVEP_Nan_update3.pptx'

% Experiment task is in the folder './Experimental code'

% Current behavior results are in the folder './Project update_Presntations/Behavioral results_SSVEP study_V1 11062021.pdf'



%%%%%%%% Datasets Overview %%%%%%%%

% What is content of the dataset: In order to check whether we can build-up ssvep response in 4 kinds of frequency-band search display regions (e.g., 17.14hz, 20hz, 24hz, 30hz) as we used in current formal experiment. After participant finished the formal experiments, they must watch the 5-minute flickering disks while keeping their eyes in the fixation cross.


%The datasets are cleaned and epoched (epoch_marker241) from the 5 minutes post-testing flickers (-1 300 secs) and selected 8 channels (O1 Oz O2 PO7 PO3 POz PO4 PO8) related to the visual region of the brain.

% Data quality issues:
I have checked all datasets and replaced the bad datasets here.
��1��For experiment1, the dataset from the third participant in experiment 1 (S01_ssvep_test.set) only has 63secs epoch duration so that the dataset size is a bit small.
��2��For experiment2, the dataset from the 7th participant in experiment 2 (SS07_ssvep_test.set) only has 211secs epoch duration. For the same reason, the 'SS02_ssvep_test.set' dataset is 235 secs datapoint, the dataset 'SS06_ssvep_test.set' is 214 secs datapoint.

% The datasets for each experiment was in the folder './EEG data and analysis/Data_exp1', or './EEG data and analysis/Data_exp2', and the preprocessing procedure and parameters in the scripts 'preprocess_exp1.m' or 'preprocess_exp2.m'.



%%%%%%%% Other files %%%%%%%%

% In the folder './Project update_Presntations':
(1) some literatures
(2) my analysis results for the 5-minute datasets in EEGLAB 'Results_check peaks of flicker_hanning_0.5s_2s.pdf'
(3) the synchronization testing results in the file 'The synchronization of all flickers testing with the external photodiodes.pdf'

% May be useful scripts from others people online for the SSVEP analysis:
(1) https://neurotechx.github.io/eeg-notebooks/auto_examples/visual_ssvep/01r__ssvep_viz.html#stimuli-specific-psd
(2) https://mne.tools/stable/auto_tutorials/time-freq/50_ssvep.html?highlight=ssvep