case_images: PMC10560731_01
case_images: Time sequence for study design. After subjects were enrolled in study, a battery of visual and cognitive skills standardized tests were administered at the beginning and end of this study, results reported in Tables 1, 2. After standardized tests were administered, the PATH neurotraining program was administered for 8 weeks. The details of the PATH neurotraining program are presented in (A-C) and in the video (https://youtu.be/HgCZn9uVdS0). (A) Sample patterns for intervention at Complexity Level 1 for a background two octaves lower in spatial frequency than the test frequency, one octave lower in spatial frequency than the test frequency, equal in spatial frequency to the test frequency, one octave higher in spatial frequency than the test frequency, and two octaves higher in spatial frequency than the 0.5 cyc/deg. "fish shaped" test pattern. This same set of backgrounds was presented in this order for each of the 4 test spatial frequencies (0.25, 0.5, 1, and 2 cyc/deg). (B) Complexity levels 2, 3, and 4 display multifrequency backgrounds for center pattern in 1.A (0.5, 0.5 cyc/deg), having the same fundamental frequency as in complexity level 1, with a difference frequency equal to the test frequency, increasing the background contrast from 5 to 10 to 20% contrast. (C) A typical trial for PATH to Reading /Insight intervention. Pattern flashes on screen for <= 450 ms while center stripes move left or right. Screen goes blank, waits for left or right arrow key to be pushed. If incorrect, short tone sounds. As soon as left or right key pressed, next pattern with same or different contrast flashes on screen while center stripes move left or right. This sequence of patterns is presented continuously until the contrast threshold for this pattern is measured (20-40 trials). At the end of each contrast threshold measurement, a fishnet appears with a fish for each pattern having a contrast threshold <= 1% contrast, personal best score, current score, and number of patterns remaining. Then the next pattern combination is presented to measure next contrast threshold until all 20 PATH neurotraining patterns were presented, and the program says 'Thank You', presents a star for each level of complexity completed, shows a graph with the contrast threshold function (optimal, current, initial) for each test frequency with its 5 background patterns, and quits.
case_images: fneur-14-898781-g001.jpg
case_images: PMC10560731_01_fneur-14-898781-g001.jpg
case_images: fig1
case_images: The patented visual timing intervention1 uses dim grayscale patterns optimal for activating magnocellular (magno) neurons to retrain the brain's pathways, see Figure 1 and https://youtu.be/HgCZn9uVdS0. The subject sat 57 cm in front of a 13-inch MacBook Pro computer monitor, with a display similar to the ones in Figure 1. When the screen went blank, the subject reported which way the center pattern moved by pushing the left or right arrow key (Figure 1C). There are also levels of difficulty introduced by making the background pattern more similar to that in the fish, see center pattern in Figure 1A, and by increasing the pattern's complexity level (Figure 1B). The complexity level increases: (1) the number of sinewave components in the background from one (Figure 1A) to three harmonically related frequencies having a difference frequency equal to the test frequency (Figure 1B), shown previously to facilitate movement discrimination by providing a wider background frame of reference, (2) the background contrast from 5 to 10 to 20%, to increase the amount of parvocellular activity, since magno-cells saturate at 10% contrast, and (3) the pattern's speed of movement after every 4 complexity levels, increasing from 6.7 to 8 Hz (in theta range) to 10 to 13.3 Hz (in alpha range), so that the subject was challenged as the training progressed. A full training cycle of the movement-discrimination task required 20 contrast threshold determinations: for each of the four test spatial frequencies (0.25, 0.5, 1, and 2 cyc/deg) paired with each of the five background spatial frequencies (equal to test frequency or +-1 or +-2 octaves from the test frequency), patterns chosen to optimally active magno-cells, see Figure 1A. MRI used for superimposing the functional activity on top of the brain anatomy was done before initial MEG recording. MEG responses evoked by a 2.5% contrast 1 cyc/deg. sinewave grating moving left or right at 10 Hz relative to a 5% contrast 1 cyc/deg. background, using the same time sequence, as described above and in Figure 1C, was collected using the VectorViewa whole-head MEG system (Elekta-Neuromag, Helsinki, Finland) with 306 MEG channels.