Analogous processing based on manipulating with level of signal for which purposse this level must be known and independant of factors not containing information. If linguistic processing in the brain were based on the intensity of signals, the brain would necessarily have the ability to precisely measure levels of signal's intensity. Moreover, various influences, such as drugs, or even simple excitement, can greatly affect the intensity of brain signals. These changes however, except in rare cases, do not affect linguistic processing. I therefore conclude that analogous processing in the brain is not probable.
Digital processing has the capability of using, two, three or more digits for encoding information.
The binary code, typically used for manmade informational devices, uses binary numbers such as 11 which equals decimal 3, or 101 which equals decimal 5 and physically expresses them in a combination of impulses for ones and absence of impulses for zeros. It is easy in a computer, with its quartz clock and set frequency of series of signals. The brain, however, lacks the capacity to precisely measure and to maintain standards of frequency. Even if these capabilities existed normally, the frequency of brain activity is ever-changing, depending on the type of activity or the influence of drugs, yet the speech function is affected by these changes in only the rarest cases. I therefore conclude that there must exist a special kind of binary code in the brain which does not depend on the precise measurement of time.