RESPONSE STRENGTH IN MULTIPLE SCHEDULES¹

Abstract

In several different experiments, pigeons were trained with one schedule or condition of food reinforcement for pecking in the presence of one key color, and a different schedule or condition in the presence of a second key color. After responding in both of these multiple schedule components stabilized, response-independent food was presented during dark-key periods between components, and the rates of pecking in both schedule components decreased. The decrease in responding relative to baseline depended on the frequency, magnitude, delay, or response-rate contingencies of reinforcement prevailing in that component. When reinforcement was terminated, decreases in responding relative to baseline rates were ordered in the same way as with response-independent food. The relations between component response rates were power functions. Internal consistencies in the data, in conjunction with parallel findings in the literature, suggest that the concept of response strength summarizes the effects of diverse procedures, where response strength is identified with relative resistance to change. The exponent of the power function relating response rates may provide the basis for scaling response strength.

Adaptive Behavior and Learning

“…Rachlin (1973) has proposed a non-quantitative theory of contrast similar to the dynamic model sketched out at the end of this chapter. In recent years, Nevin and his associated have elaborated a theory of behavioral "momentum" that can accommodate a wide range of contrast and choice phenomena (e.g., Grace, 1994;Nevin, 1974;Nevin, Tota, Torquato, & Shull, 1990) 12. Use of the term controlled to refer to the effect of a stimulus on a response is conventional, but it is not quite accurate.…”

“…I compare Herrnstein's approach to the problem of multiple schedules with an alternative proposed by Nevin and his associates and show the common features that underlie them. Nevin (1974), impressed by similarities between physical and behavioral "momentum," suggested that response strength is best understood not in terms of response rate but in terms of resistance to change. The idea is that a "stronger" response is not necessarily one that occurs at a higher rate but one that maintains its rate better in the face of challenge, i.e., has a higher behavioral "momentum" He tested this idea by arranging different conditions of food reinforcement in the presence of two or more successively alternating stimuli -components of a multiple schedule.…”

“…A typical "momentum" result is illustrated by Nevin's (1974) pigeon study, which used a multiple schedule with three components, signaled by a either a Red, Green or dark (timeout) response key. Red and Green key presentations lasted for a minute each and were followed by 30-s timeouts.…”

Some Effects of Magnitude of Reinforcement on Persistence of Responding

“…Specifically, the influence of different dimensions of reinforcement on behavioral maintenance other than rate, such as magnitude of reinforcement, should be explored further. In an earlier study, Nevin (1974) observed that magnitude had similar effects as rate on 2 pigeons' response persistence. Rate of reinforcement was held constant at a Variable Interval (VI 1 min or VI 3 min) schedule, whereas duration of food availability varied from 7.5 s to 2.5 s. When free food was available, pigeon response rates were less resistant to change when reinforcement length was relatively less (i.e., 2.5 s), although 1 pigeon was equally persistent during VI 1 min regardless of the duration of reinforcement.…”

Polêmicas sobre história comportamental: identificação de seus efeitos e sua duração

“…Uma linha de pesquisa que aparentemente trabalha precisamente com essa questão é a do momento comportamental ou resistência à mudança (e.g., Lattal, 1989;Nevin, 1974;Nevin, Mandell, & Atak, 1983). Seria interessante que pesquisadores interessados em ambas as áreas, história comportamental e momento comportamental, desenvolvessem projetos conjuntos, em que tais questões possam ser sistematicamente avaliadas 8 .…”