Sequential visual reaction times

The reaction-time to a series of successive digits was measured on two subjects. After practice, it was found that whilst the reaction time to the onset of the series was constant at 150 ms, the response time to additional digits became less and less to asymptote to a level of about 50 ms. The time course of this ‘chorus-line’ phenomenon was studied in greater temporal detail by varying the interval in steps of 20 ms. The effect was greatest at 200 ms. Thereafter, it declined and for long intervals reached the value of a standard reaction time. On a third inexperienced subject, the learning period was established; this was about 300–400 presentations. The implications of these findings are …