Brain consciousness is directly connected to the activity of the neurons both in the head and spread throughout the body. These neurons divide functionally into 3 groups - sensory-neurons, motor-neurons and inter-neurons.
Sensory-neurons receive sensory information from both the 5 external senses (sight, hearing, smelling, taste and touch) and the 5 main internal senses (pain, muscle change, joint movement, pressure, and temperature). Motor-neurons initiate motor impulses to control muscle function, control the chemical balances and stimulate the endocrine system. Inter-neurons mutually stimulate each other in intelligent patterns. Only a small proportion of this final activity - mutual stimulation - produces conscious thought. To use various methods to stop conscious thought, typically with enhanced awareness of the information from the 5 external senses, produces a slightly unusual state. But in this simple brain state the main mass of neurons are still fully active, mostly on a subconscious level. Then to base all further progress on this 'slightly unusual' state is to trap your consciousness in the brain (which is just part of the body) and will not lead to the deep part of yourself nor to the inner worlds.
As the 2 most active outer senses are seeing and hearing, people trapped in the superficial-mind typically take on a fixed stare and talk with a carefully considered air while perhaps moving slowly and deliberately, all so as not to disturb their quiet awareness based in their external senses.
In that superficially quiet brain state with enhanced awareness of the outer senses, people unrealistically imagine that they then experience reality through pure awareness. In reality the mass of subconcious activity of the brain with all its unrealised conditioning dominates and distorts communication with their inner self. This quiet state cannot in itself carry the person beyond the reach of their own ego. Those teachers basing their methods in this quiet brain consciousness typically then stress the idea of 'being present' along with the idea that past and future do not exist, not realising that past, future and present are all simple brain perceptions. The deeper parts of a person do not operate in this time frame. Existence as a whole - including past, future and present - manifests simultaneously in the "ever present here and eternal now" in a way that is understood only according to the depth of Being used to perceive it.
Only deep training with someone who has themselves escaped the brain consciousness has any realistic hope of success. No system devised by thinking or found spontaneously from this quiet brain state will lead people to freedom. So, sadly throughout history, millions have meditated in each generation, while only a few have found the freedom of the True Self. Unfortunately for the deeply trained teachers, those others, who basing their systems on the few flashes of inspiration that do occasionally occur in the quiet brain state, mislead the mass of seekers, attracting them with systems that seem to require little effort.
Ramanamaharshi: "There are different kinds of silence. In the pursuit of inner silence one should not enter laya [temporary suspension of mental faculties]. If you remain in this [trance like] state no benefit will come to you. A complete absence of thoughts does not mean that one is experiencing the true silence of the Self. If there is a sense of freshness and clarity [of perception and understanding] in the silence, if one feels joyful and utterly peaceful, this is more likely to be approaching the real silence."