The Space Between Analog and Digital

I wrote the paper below as part of an assignment for a class I took in the late 1990s. It relates to a recent visual post (Analog and Digital Realms) as well as to the original mission of this blog (which was to autism from my perspective as a sibling of an autistic brother). In the text that follows, I first define the terms ‘analog’ and ‘digital’, then I explore the in-between realm.  The reader may skip to the final several paragraphs to see my conclusions with respect to autism.

The Space Between Analog and Digital

Evidence of analog and digital worlds impinges upon us from our very earlier experience. Who is the baby who doesn’t drool (an analog act)? Which baby’s fuzzy, inarticulated world doesn’t seem to be an extension of itself? The world is an integrated, smooth continuum, from the soothing voices, to the suckling at the mother’s breast, the satisfaction of release (after the analog process of digestion), the sleeping and everything else. Soon however, baby comes faces to face with the digital world: the dreaded, bistable states of ‘yes’ and ‘no’. In the case of some family environments which are testaments to the dynamic equilibrium of trinity-state, fuzzy logic systems (i.e., yes, no and maybe) although the time scale of such equilibrium is frequently measured in years.

But I digress.

What do we mean by analog and digital? An analog computer was simply an electrical circuit that was build according to the specifications of a mathematical equation. Certain electrical components multiplied, others divided or integrated and some differentiated. The signal put into the circuit represented the input to the problem and was transformed by its elements, while the output represented the answer. There were many inaccuracies. Tolerance on individual components could add up to be quite significant (i.e., the closest commercial tolerance on resisters is generally 1 percent, with capacitors and inductors rated similarly). Furthermore, this system did not work well if the input signal was not a continuous waveform. Numerical analysis shoed mathematicians a way that one could chop up any waveform into discrete numbers. In essence, a continuous wave could be replaced by a connect-the-dot figure. There were some disadvantages to techniques of this nature. First of all, connecting the dots does not give one exactly the same waveform as before. It is no longer a smoothly varying entity. In reconstructing a smooth wave, the fidelity to the original depends on the number of dots and how close together they are. A frequency analysis of the resulting reconstruction will yield a differing spectrum from the original. However, the difference is controllable, unlike the components of an analog circuit. One may choose to increase the number of dots (or samples) until the desired fidelity is reached. Of course, with the increase in the number of data points, comes the need to store this data for processing (reconstruction, at the very least). With the data storage capacities of today [circa 1998] and the promise of higher data density tomorrow, this does not seem to be an issue. The power to choose the appropriate fidelity allows for a theoretically undetectable difference in waves reconstructed from the numbers.

The difference between analog and digital, in this context is the tiny difference between the straight line connecting the dots and the smooth curve of the signal between the same two dots. This difference is known as the “error”. The closer the dots are to each other, the lower the error. the closer the dots are to each other, the higher the “sampling rate”, as mentioned above. There comes a point, for example, in the sampling of a sound signal, where the sound wave reconstructed by the dots, sounds just as good as the original (i.e., the difference between the two could not be detected by most individuals). Theoretically, there is a sampling rate that can reproduce a wave with all the frequencies that the human ear can detect. This rate is used to record most music these days.

There are analog and digital processes inside the brain and in our nervous system. A nerve cell does not pass each and every impulse that impinges upon it. A threshold must be exceeded first. Then a non-degraded pulse runs the length of the axon. This all-or-none response is digital in nature. When the impulse gets to the end of the nerve cell (the dendrites), individual sacks of chemicals are released into the gap between it and the next nerve cell. After they are released from the sacks, the chemicals add together to gradually change the electrical properties of the next cell (analog).

How is it that some people (i.e., audiophiles) say that they can hear a difference between an analog and digital audio signal, sampled at an essentially error-free rate? If these claims are true, either the frequency response of these individuals is extraordinary or there is some kind of biological process that detects a different characteristic of the digital or analog signal. Conversely, one may ask, “What is that ‘space’ the audiophile occupies in order to enjoy the “errorless” audio signal” What is it about the infinitesimal error in digital audio, that takes away from the audiophile’s appreciation?” It seems to be an indefinable quantity and a hard-to-describe quality.

The “space in-between” seems to be where my brother [hyperlink added] resides. He is autistic and profoundly retarded. [Note: ‘profound retardation’ was a diagnosis found in one of the early Diagnostic and Statistical Manual of Mental Disorders. No disrespect was intended in the original text.] He doesn’t talk. It is impossible to get him pro pay attention. “He’s in his own world,” was the explanation I used to get as a child. Where is that world? Is it made up of connections in his brain? Is he conscious like other people? Just like us, my brother feels pain, goes to the bathroom and eats. That is what we have in common. We have my parents in common also. So why is there that huge gulf of being, between us? Maybe he’s off a gene or two (a mistake in the digital code of life?). Maybe the chemical environment (analog) in his brain did not allow him to develop as I did. Still, after many years of seeking commonality with him, I have concluded that yes, there is some. Where does it reside? I don’t know. Maybe my own mind has imposed its own order on the facts and observations I have made. However, I fee that there is a live on which we both exist and acknowledge each other.

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