Though all mediums are unique and different in what and how they do, there are still common principles to how they open the channel, keep the channel open and remain in a stable and secure state while doing the work. Most typical patterns for mediums are Awakened Mind (Flow), Channelling (Trance) and Evolved Mind (Oneness) and much rarely we may see what we call Out-of-Body Pattern (Nobody home). The main difference will be how much the person stays in this or that pattern, as well as how stable the flow is, and if there is any Gamma activity.

Mediums show patterns of higher states and training levels similar to those of long-term meditators, i.e. the nature of work is similar to regular deep meditative practice that eventually leads the brain to more optimal states. This can explain why this work is a kind of 'addictive' in a healthy way: our brain simply likes to go back to the more optimal and balanced states!

Almost all mediums will show Alpha bridge with eyes open. And, with eyes closed Alpha will be even bigger. I assume, this is the results of a regular training with eyes open that allows them to make sure they have the flow and access to the trance states.

Mediums have very active Delta, i.e. main psychic 'muscle' for mediums, healers, readers. The Mind Mirror Manual says that the average amplitude of the most of people would be in between 3 and 12 microvolts. For those with psychic abilities we may expect Delta to be 10 or even 20 times higher and go the whole way above 100 microvolts! (See below the patterns from 4 different mediums.) Due to the nature of their work (with eyes open), they will tend to show more Delta with eyes open!

Some mediums demonstrate more Gamma activity, i.e. jolts/shifts in their energetics during mediumship sessions.
1) With some, it looks like, it is their Beta activity and setting the intention that triggers Gamma open.
2) With others, it could be Delta activity. Though purple Delta is in the bottom of the pattern and Gamma on the very top, we know that they have their own line of communication, as if it flows in a toroidal pattern, Delta surges may cause Gamma shoot out too!

Mediums have independently flexible Theta, it feels like it literally can go any side and stretch any corner with individual Theta bands sticking out from the rest of the pattern or forming unusual configurations. If it was just the lowest band pulled by strong Delta surges that could be explained but this can be any of the 3 Theta bands (see the pictures below). One medium pointed out that potentially it may look like 'holding the connection'. Read more of my insight about this in the next section below.

This observation, also made me make an assumption that those who are not natural and who were guided or train themselves to do this work, will inevitably face some materials from their own subconscious mind (Theta) and will have to work through it to make mediumship work possible. Comparing it with those meditating, we can say that mediumship work will be equally a call for inner healing and clearing the suppressed 'stuff' from the subconscious. Many mediums will confirm that even if they do not feel they have cleared all their stuff, they had hard times in life that led them to opening their hearts more. As the above psychic medium said describing the Evolved Mind pattern, you need to become one with another person to be able to access the information stored in one's energy field and, no doubt, you need to accept others non-judgmentally and keep your heart open to make this happen.

Mediums have a very strong and loving connection with their group. When doing the Bubble meditation, all members showed beautiful Evolved Mind pattern approximations or unusual activity in their Theta bands when sitting in a group consciousness bubble. When they commented on inviting others in the group into their energy bubble, they tend to let those in first with whom they normally do sittings or their mediumship work with. When they did so, they all claimed to feel more of their own power, as if others were amplifiers for their power (the similar effect was observed when they were asked to invite loved ones into their bubble). What a great metaphor for the Evolved Mind as the power of unity and oneness!

The above mentioned comment on unusual independent sticking Theta bands behaviour is relevant here too, since mediums said they invited all member of the group in, including their spiritual group. Thus, the assumption about 'holding the link' showing up as one of Theta bands sticking out could be true. Another argument for this is that from my own experience and those of people I know, even if you are not a medium, many have mystical experiences of seeing the deseased family members and dear friends in their dreams (REM sleep), which as we know, also is related to Theta activity.

When asked to leave the group bubble, some even showed signs of resistance and stress.