An ecological sense of self and of mind might be helpful. It is for me. To me "mind" is nature's system for processing information. From the standpoint of the entire universe each person is a tiny speck, but nevertheless has a mind, as do all other living instances and collections of life.
Each individual human can conceive if itself as the center of a personal universe. I don’t know of another species that has the capacity to do that. We are biological creatures, vulnerable in so many ways. Our individual minds are centered and coordinated in our brains. They don't as far as I know function unless they are each connected with the rest of our bodies, moreover with the outside world. We are connected with the outside world through distance receptors like eyes and ears, which receive information encoded in patterns of light waves and sound waves, respectively.
These patterns are codes that we evolved culturally to be able to receive and eventually make sense with. What I am writing is PATTERNS like ink on paper, which stand for words that stand for things and concepts. The black on white text is not the things it stands for. Korzybski pointed out the obvious, “The map is not the territory!” Information, the mind, rides into my being, for example on patterns of matter and energy in the form of light wave and sound wave frequencies and amplitudes.
The information is not, itself, the matter and energy, but a code that changes its form as it travels into, and around, in specific areas of the brain, where it makes dynamic loops. The processes where the changes in form of impulses occur, such as the retina or the eardrum, are called signal transduction. The key words are CODE and PATTERN. Sensorimotor loops occur at the speed of neural impulses, considerably slower than the speed of light or sound, down into the rest of the body, back up into the brain, and are reflected back into the outside world through how we behave. All sorts of dialogues are possible.
Possibly the most neglected aspects of these loops are those that bring into play our endocrine and autonomic nervous systems. They provide one of the most primitive and valuable aspects of who we are and can be. They are an integral and necessary element of a healthy mind. When neglected or battled against they contribute to depression, anxiety disorders and poor social and other judgment. Adrenaline, noradrenaline, dopamine, serotonin and other neurotransmitters can arouse us spiritually. They can also frighten us, especially if we have been taught that sad is bad, or that fear is weak, or that assertiveness is aggressiveness. Patterns of nuances of feeling that stand out sharply clear a path for memory of what is important: what is safe and nurturing, what is dangerous.
We loop with ourselves and the world through thinking, feeling, and behavior in dynamic ongoing fashion. It is a profoundly aesthetic experience for many who are able to accept sense of self as depending on healthy connections with the world outside and the world inside.
These examples are just a scratching of the surface of the processes of mind. We might conceive of Nature as a SuperMind, of which each living information-processing entity is a part. We are all connected, either by what we have in common or by the messages we send and receive.
Ortega y Gasset said, "I am myself plus my circumstance." Our connections with our important others are mental. I include healthy integrated emotional experience as an essential part of my own mind. Only when that exists is my judgment optimal.
We might extend our mind's sphere by including, inserting into it, devices that are mechanical or electronic. We might use them to connect with people, like I am doing now.
Or consider the Tom Hanks character in Castaway who was marooned for four years on an island with no people. He had no iPhone or other electronic device. He got blood on his hand doing a dental procedure on himself, then had the bright idea to paint a face on a volleyball with his bloody hand. Many were the conversations.