EFFECTS OF A CONCURRENT TASK ON FIXED‐INTERVAL RESPONDING IN HUMANS¹

Abstract

Subjects pressed a telegraph key to illuminate a meter dial on which pointer deflections appeared at fixed intervals. Upon detecting a deflection they were required to press another key to reset the pointer to zero. This detecting and resetting operation reinforced the behavior of pressing the light-flashing key (i.e., the observing responses). The usual pattern of responding on the light-flashing key was a long pause following the reinforcement and an abrupt transition to a steady response rate toward the end of the interval. When the subjects were required to perform a concurrent subtraction task, the pattern of responding changed in varying degrees, ranging from complete loss of typical fixed-interval behavior to a slight shortening of the post-reinforcement pause. These effects were attributed to the disruption of the self-produced verbal chains (counting or reciting) that ordinarily govern human behavior on this schedule.

CONTROLLING HUMAN FIXED‐INTERVAL PERFORMANCE1

“…Other humans pause after reinforcement either for the entire time between reinforcements or for a shorter period, after which some terminal responding precedes reinforcement. The rate of such terminal responding may be positively accelerated (Holland, 1957(Holland, , 1958 but more frequently it is relatively constant (e.g., Azrin, 1958;Laties and Weiss, 1963).…”

“…Other procedures that were effective in producing low-rate performances under Fl schedules with humans include (1) adding a DRL contingency to an FI schedule (Long, 1962); (2) providing subjects with an external clock or some cue concerning the temporal aspects of and Fl contingency (Azrin, 1958;Long, 1962Long, , 1963; and (3) having subjects perform a concurrent task (Laties and Weiss, 1963).…”

Effects of Instructional Constraints on Human Fixed‐interval Performance

“…The oscillatory, "pause-respond" pattern characteristic of animal performance-whether it be of the scalloping or break-and-run varieties-is often considered indicative of sensitivity to the temporal structure of the FL contingency. By contrast, such patterns in human performance have persistently eluded researchers (e.g., Baron et al, 1969;Bullock, 1960;Laties & Weiss, 1963;Matthews et al, 1977;Weiner, 1965Weiner, , 1969.…”

Why Behave? The Problem of Initiating Causes and the Goals of Prediction and Control

“…In the 1960s and early '70s, several authors began reporting results from operant experimentation with humans that deviated from what was to be expected, according to the animal literature (e.g ., Ayllon & Azrin, 1964;Laties & Weiss, 1963;Weiner, 1970). In a peculiar way, people seemed insensitive to consequences of responding, and many authors were at a loss when trying to explain why (e.g., Ader & Tatum, 1961;Weiner, 1962Weiner, , 1964.…”

“…Others, however, acknowledged the difference and wanted explanations. Among the first to do so within a behaviorist tradition were Lovaas (1961Lovaas ( , 1964, Laties and Weiss (1963), and Ayllon and Azrin (1964), who regarded an analysis of the interaction between verbal and nonverbal behavior as the primary clue to understanding the peculiarities of human responding.…”