Reliability of Frontal Eye Fields Activation and Very Low-Frequency Oscillations Observed during Vergence Eye Movements: an fNIRS Study

Figures

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  Figure 1. Group-level hemodynamic response functions (HRF) for the oxygenated (HbO, A) and deoxygenated (HbR, B) response signal. Group-level oxygenated hemodynamic response function (HRF) from 20 participants of the average of the 10 task / rest blocks of the acquired signals. Each of the colors in the HRF correspond to a different channel based on the source-detector design. Channel 2 from Source A to Detector 2 (blue line), Channel 5 from Source B to Detector 1 (green line), Channel 10 from Source C to Detector 6 (red line), and Channel 13 Source D to Detector 5 (cyan line). The corresponding shaded colors is one standard deviation from the mean signal.

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  Figure 2. Group level HbO cortical activation map. The heat map shows the t-value of significant task-responsive BOLD activations.

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  Figure 3. Frequency spectrum of HbO of Channel 2 for two different participants (plots A, B) showing the two peak-intensity signals, one denoted with a * and the other with a square. The experimental task has a frequency of 0.025 (C) shows the peak power and its corresponding frequency of all 20 participants.

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  Figure 4. (A) Source-detector (SD) configuration, the source (red) and detector (blue) optodes are denoted as circle, functional channels are denoted as squares, and the FEF location is denoted by the gray FEF circles. All channels have 30 mm SD distance except for channels 1, 6, 9, and 14 which have an SD distance of 10 mm. (B) The experimental block design was composed of sustained fixation (denoted as Fixation) and vergence eye movements (denoted as Eye Mvt) which modulated functional activity within the vergence neural substrates. (C) Eccentric square stimuli; when converged upon, a person will perceive depth, where the squares will appear one in front of the other (larger to smaller). The source (pink) and detector (blue) optode locations on a skin (D) and cortical (E) overlay with the utilized FEF location in a coronal (F) and axial (G) view with corresponding optode patch location is show in the right side of the figure. The sensitivity map (H) was generated using AtlasViewer.