Putting aside for a moment the short-comings of Aristotelian two-value logic, "A thing is either A or not-A", we can think of the brain as sustaining the activity of cells whose firing represents information derived from 1) readout from long-term memory or 2) brief sensory input.
Our perceptions of reality are limited by what we can perceive with the brain. We can think of reality as a blend of:
1) MEMORY: readout from long-term memory
2) INPUT: brief sensory input
"Memory” is the brain program that is capable of responding to specific, predictable stimulus inputs, and has sometimes been referred to as being unconscious. The example of driving along a familiar route has been used by many authors to describe this type of memory.
"Whilst driving home from work our conscious minds may be busy reviewing the events of the day whilst at the same time, we are watching traffic, changing gear, following the road but are unaware of any of these operations. Yet if we encounter a hazardous situation - such as a child in the road - we instantly become aware of the child, the road, the motor operations of driving, and thereafter slow down to drive more carefully under conscious control. Our conscious mind seems to take over the control of our body in these situations." (J. McFadden, 2002)In other words, there may be some unexpected events that happen on the way to work, but things generally proceed as expected, based on what the memory program computes to be most probably out there.
The information in the adult brain largely depends on this dense and unconscious memory. Timothy Leary said that the individual world each person occupies is his reality tunnel. In the reality tunnel mode of operation, the adult brain can screen out unfavorable stimuli which are present in the environment. For example, the memory of a crack addict may construct a reality in which a crack pipe is more significant than the baby in the same room. In this reality tunnel mode of thinking, it is possible to confuse our expectations with reality.
However, activation of "memory" programs during sustained wakefulness never achieves total autonomy from the stimulus environment, because we always encounter children in the middle of the road, unforeseen traffic delays, and accidents.
BRIEF SENSORY INPUT
"Input" is the brain program that is activated by the arrival of certain unpredictable stimuli. Activation of the "input" program during wakefulness never achieves total autonomy from "memory".
There is far more information out there than the mind can behold. The brain only samples a fraction of the information out there and then it fills in the rest. The sampling of information "out there" is accomplished by the input program, while its left up to memory to fill in the rest. To the extent that memory is successful, brief sensory input will be put on hold.
During adulthood in mid-life, when we have a strong sense of memory, we are merely the brain that looks at the universe. The beauty is there, but it is the expected kind. When we forego as many expectations as possible at the beginning and end of life, we are more likely to turn on to the input, and the weirdness of the big existence. . . . Terrence McKenna referred to the Input program as an alien intelligence, "Whatever you think it is, its not what you think it is."
A hypothesis about LSD and the 2 modes: memory and brief sensory input
It seem likely that LSD has a powerful dismantling effect on memory, defined above as the reality tunnel existence in which most adult human beings operate. Anyone who has taken LSD may have experienced firsthand the uncomfortable feeling of abulia in place of a normal sense of confidence of "who I am".
LSD may cause a failure of the cortex to predict what is out there, when you begin to see things of undescribable beauty which you have never possibly seen before in your entire life. So, without prediction to guide us, nearly all experience becomes reactive and primitive. It could be hypothesized that LSD turns on the "input" brain program, or else that it turns off the "memory" brain program. Either way it leaves the impression of an influx of sensory information, followed by a reorganization of the "reality tunnel" brain program. Studies in pigeon and rabbit have shown that low doses of LSD facilitate certain types of sensory awareness that get translated into new memory. Memory of the LSD experience does not differ much from memory of any memorable event. Afterall what is an LSD flash-back besides a powerful memory recollection?
Primitive learning may happen so effectively under LSD that we caution people about making good choices about the "set" and "setting", the people and stimuli who are present when tripping.
LSD and other hallucinogens seem to be able to enhance certain types of learning without necessarily promoting the intent to learn (over achievers take note). Loss of ego functioning does not necessarily prevent memory formation, because much learning takes place without being conscious of the details (e.g. language acquisition in children).
The facilitation of a new learning experience can help people to break out of addiction, or other memory programs that have become toxic.
"[Under the influence of LSD] other types of learning may be unimpaired and may be much improved. If this were not so, the psychedelic experience would help no one. A large number of alcoholic subjects learn concepts and ideas in a few moments that they had not grasped for years. These are termed flashes of Inspiration or Insight but they seem to me to be the acquisition of new concepts. One subject, a brilliant physician alcoholic, prided himself on the fact he took no drugs. Under LSD he vividly learned alcohol Is a chemical and, by his old definition, a drug. Other subjects learned understanding, tolerance, compassion, the meaning of psychotic fear, etc." (A. Hoffer, 1956)
For convenience I have described reality as a blend of memory and brief sensory input, but Phillip K. Dick reminds us that Aristotelian two-value logic is fucked. Afterall, how would a physical reality that is separate from the mind exist when the brain emerged from this order? To quote Sherrington's pupil,
"It is not the code or the message coming from the outside world that is being transmitted, but rather it is the neuronal element that responds to the message from the outside that is itself the message! " (R. Llinas, 2001)This complicates the definition of the "input" program as having sampled something from the "outside", and is the point in the conversation when people like to mention "intrinsic properties" related to certain Ca2+ conductances.
At one extreme, the brain is capable of emulating reality in the absence of input from such reality, and at the other extreme, sensory contents gain internal context. Like the immune system, the brain may keep a border between the self and the environment, the function of which enables sensitization to the environment with time.