This is the first step in the HIRREM process, and occurs prior to the initial HIRREM session. The assessment creates a map of frequencies and amplitudes, and informs the choice of protocols for the initial HIRREM sessions. For the assessment, with the recipient in a sitting to slightly reclining position, two sensors are sequentially placed over six areas of the scalp to record epochs of data while the brain is at rest, or at task. The first minute of recording at each location is with eyes closed, the second with eyes partially open, and the third with eyes open while carrying out a task. This provides data regarding the resting state brain pattern (eyes closed), as well as the pattern under load (eyes open at task). Although the patterns may be similar with eyes closed and eyes open at task, they may be different.
For the basic HIRREM assessments carried out at WFSM, measurements are taken at specific locations on the scalp, according to the 10-20 International System (Jasper HH, Electroencephalogr. Clin. Neurophysiol., 1958), at F3/F4, C3/C4, P3/P4, T3/T4, FZ/OZ, and O1/O2. For EO assessments, recipients are given standardized tasks involving numerical digit recall (F3/F4), reading silently (C3/C4), math calculations (P3/P4), listening comprehension (T3/T4), and to relax with eyes open (O1/O2). A sixth midline measurement is taken at FZ/OZ, with an EO task to count the number of appearances of a specific word as they read a standardized printed passage. The reference sensors are connected at A1/A2 and linked for assessments. The data are processed to identify patterns and imbalances of frequencies and amplitudes, which the Technologists use to inform the choice of specific protocols for the initial HIRREM session. The assessment takes about 30-45 minutes to complete.
Figure 2: Moving from left to right, this demonstrates the sequence for a HIRREM assessment at the frontal location (F3/F4) including recording with eyes closed, eyes partially open, and eyes open during a reading task.
HIRREM data can be displayed several ways. One method is the use of a spectrograph to display electrical frequencies (Hertz, vertical axis) and amplitudes (microvolts, horizontal axis) recorded from the left and right sides of the brain (left and right half of display, respectively) at specific locations during an epoch of time (i.e. one minute with eyes closed). Below are examples of spectrographs obtained during the assessment on one research subject enrolled in the Developmental Study due to TBI, insomnia, and PTSD (Figure 3, A-B). These pre-HIRREM assessments from the temporal regions (T3/T4, left/right) with eyes closed (A), and eyes open at task (B), show different baseline patterns for each eye state. With eyes closed at rest (A), there are higher amplitudes on the left in the higher frequencies (23-55 Hertz, outlined by a red box below, up to 74% greater on the left), while with eyes open at task (B) there is right dominance in the same frequency ranges (up to 248% greater on the right). Spectrographs, those below, and others on this webpage, were created using Brain State Technologies’ Optimization Suite.
Figure 3-A: T3/T4 assessment data with eyes closed
Figure 3-B: T3/T4 assessment data with eyes open at task