Category perception, language and brain hemispheres: An information transmission approach

Applying information theory to living systems suggests a hypothesis: The larger the number of times a signal is retransmitted in a noisy channel, the smaller is the optimal number of categories into which a sample of the signal can be broken down. This cross- level hypothesis is tested at the organism and organ levels of living systems. At the organism level, the hypothesis suggests that the “magical number” of categories into which a person breaks down information input is a function of signal-to-noise ratio. This number drops when one anticipates having to retransmit information which one has received. At the organ level, the hypothesis suggests a reason for the hemispheric specialization in the human brain. In particular, since information to be retransmitted seems first to undergo verbalization and since the optimal number of categories decreases when information is to be retransmitted, the left hemisphere of the brain, the verbalization hemisphere, has a smaller optimum number of categories than the right hemisphere. A review of empirical evidence indicates that it generally supports the hypothesis. Suggestions for further studies include possible research to other levels of living systems.