The Capacity for Generating Information by Randomization

Response selection was studied independently of the stimulus by asking subjects to generate random sequences of letters or numbers. Experiment 1 varied rate of letter generation from ½ sec. to 4 sec. per item and showed that the redundancy of the sequence increased linearly with rate. Experiment 2 added random generation of letters as a secondary task to paced card sorting. Information load per card was varied from 1 through 2 to 4 to 8 alternatives, with sorting rate held constant. As predicted, the redundancy of the sequences generated increased linearly with sorting load. Experiment 3 varied number of items to be randomized. Rate of random generation increased systematically from 2 to 4 to 8 alternatives, but levelled out beyond this point, showing no difference between 16 and 26. In general, these results suggest a response-selection mechanism of limited informational capacity.