The human sensory system is a filtering system. Physical form and activity are perceived by the senses and translated into modulated streams of ionic current. These currents are moved though the body, via the nervous system, to the brain. Specialized brain regions receive and decipher these modulated current signals to process them for interpretation by other functionalities operating within the body.
There are volitional and non-volitional (autonomic) aspects to our bodies. We can consciously and intentionally stimulate motor neurons, which innervate muscle fibers, to move our bodies. Other processes, like heart rate, digestion and perspiration are primarily subconsciously mediated. Some actions, like breathing, are subject to both subconscious and conscious control. And certainly, our conscious thought rests upon an emotional sea and our emotions are linked to autonomic processes in our bodies. If aroused, we can experience increased heart rate and perspiration. If we are happy, delicate muscles in our face contract to create a smile. Our mood, which stimulates our conscious thought, will influence our perception because our emotional substrate acts as a neurological filter.
There is no clear separation between the medium either outside or inside the body. Human perception encompasses a continuum of medium filters. And also, the links between body and environment are richer than these connected medium filters. There is a resonance that’s established between body and environment that is subject to the cause and effect relationship between physiological and emotional state. We are stimulated by the environmental medium, and in turn, we can manipulate that medium, thus mixing cause and effect.