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Effects of response force on conjugate rates
khav.
Rex
k Therapy.
1969. Vol.
7. pp. 331 to 333.
Perpamm
Prus..
Printed
in En!&nd
Effects of response force on conjugate rates (Received 14 December 1968)
Summary-The effects of increased response-force on conjugate response rates were investigated by two procedures which required subjects to work to maintain the intensity of the audio and video channels of a continuously available filmed narration. In the first procedure nine normal boys responded via handswitches requiring 600 g of force to operate while another group of nine boys used handswitches requiring 3000 g of force. The high force group emitted significantly lower rates than the low force group. Added force also increased behavioral responsiveness to two deceleration contingencies. In the second procedure a single group of six learning disabled boys worked under two force conditions. Added force resulted in significant group differences on one of the arrangements of consequences. It also amplified the effect of the deceleration contingencies, and clarified differences in the consequential value of the two narrations. Increasing the response-force requirement heightens the sensitivity of a conjugate analysis of preferences. A CONJUGATE arrangement of consequences provides one of the most sensitive and efficient laboratory methods for analysing consequence preference (Morgan and Lindsley, 1966; Lovitt, 1967,1968; Mira, 1968). Certain factors which may reduce the sensitivity of the procedure by interfering with the effects of the experimental variables include potent social consequences overriding the effects of experimental contingencies, response differentiation deficits in multi-operanda procedures, and delayed or lack of deceleration when responding is inconsequated. One way of increasing the sensitivity of the conjugate procedure is to maximizt the response rate requirement (Nathan, Schneller and Lindsley, 1964). The present study investigated the effects of increasing The effects of the response-force reqiurement as another means of amplifying sensitivity of the procedure increased force requirements on response rates under a conjugate schedule have not been previously reported. This investigation compared the responses of two groups of normal subjects each working under different response-force conditions, and also compared responses of a group of learning disabled children under two different response-force conditions.
METHOD Apparatus Two handswitches
in the experimental room controlled, via traditional circuits, the intensity of the auditory and visual narrations of a 16 mm sound movie which were programmed through two conjugate servo mechanisms. The video portion of the film entered the experimental room through a wall opening behind the subject; the audio channel was presented via headphones. Two cumulative recorders provided the record of the subject’s responses on the handswitches. Subjects The subjects were 18 normal achieving boys, ages 7-l
1, and six academically retarded boys of the same
age range who were enrolled in a special program. Procedure I The 18 normal boys participated
individually in a single I-hr session during which six different arrangements of consequences were presented. Nine boys used handswitches requiring 600 g of force to operate, the other nine used switches requiring 3000 g. The high and low force groups were of comparable age. The six arrangements were as follows: Arrungemcnt 1. The video and audio channels were programmed independently to increase in intensity when the respective hand-switches were activated. Arrungement 2. Video and audio channels each decreased in intensity upon switch activation.
331
332
CASE HISTORIES
AND SHORTER
communications
,-irrafige/~renf 3. Video increased and audio decreased when their respective switches were activated, so that subjects had to press the video switch and simultaneously stop pressing the audio to look and listen. Arrungemenf 4. Video decreased and audio increased when their respective switches were pressed. Arrangenlent 5. Both narrative channels were programmed through one conjugate servo for this and the following arrangement. Activating the operative switch increased video and decreased audio, so that the subject could look or listen but not both. The other switch was inconsequated in that pressing it had no effect on either narration. Arrangement 6. Activating the operative switch increased audio and decreased video narrations. The second switch was inconsequated in that its activation had no effect on either narration, Procedure II
Each of the six academically retarded subjects p~ticipated in two one hour sessions seven to nine months apart. Handswitches requiring 600 g of force were used in one session, 3000 g switches in the other. The arrangements of consequences were similar to Procedure I.
RESULTS Procedure I. Two groups of normals
Increased response-force was associated with significantly lower response rates under all experimental arrangements in which responding increased the intensity of a narration. Despite diminished rates, subjects in the 3000-g group obtained narrations at maximal intensity since the rates required to maintain full intensity, having been functionally predetermined for each subject, were correspondingly lower. Table 1 presents the median response rates based on each subject’s rates during the last three minutes of each arrangement. TABLE 1. GROUP MEDIAN RESPONSERATES UNDER TWO RESPONSEFORCEREQUIREMENTS
mg
3@og
Fisher Exact y value 0~000oooo3 0030017
I
Video switch: increase Audio switch : increase
78 66
32 22
2
Video switch: decrease Audio switch: decrease
0 0
0 0
3
Video switch: increase Audio switch: decrease
105
5
28 0
0@00016 0.15
o-2 0.28
4
Video switch: decrease Audio switch : increase
14 76
0 27
0.19 0.0~019
5
Operative switch: video increase, audio decrease Inconsequated switch
70 36
21 7
0900005
Operative switch: video decrease, audio increase Inconsequated switch
16
44
t 1
6
04005
0.14
0.01
There was a significant (p 0.003)’ difference between the groups in immediacy of response deceleration under Arrangement 2 in which both channels diminished upon responding. In the low force group 38 per cent stopped responding within a few seconds upon institution of the arrangement, while 72 per cent of the high force group immediately decelerated to zero. In the high force group absolute rates under inconsequation were more suppressed (Table 1) and immediacy of complete deceleration significantly mote frequent (p OJJO4) than in the low force group. No low force subject stopped pressing immediately on the nonfunctional switch under Arrangement 5 or 6, while three high force boys decelerated immediately under Arrangement 5 and four did under Arrangement 6. * All probability
figures in this report are based on the Fisher Exact p.
333
CASE HISTORIES AND SHORTER COMML’NICATIONS
Among the normal subjects increased force had a limited effect on preference. Subjects in both groups chose to look and listen simultaneously when they could. When they could not do both, the high force subjects most frequently chose to look (six of the nine). while among the low force group two chose to look and five responded at less than the maximum rate and obtained both narrations, each at diminished intensity. Procedure
II. Same sahjec~s
Increased force diminished absolute rates of all six academically retarded subjects under all contingencies. but the suppression was significant only for Arrangement 2 (p 0,007 for video switch and 0.0046 for audio). Added force also made behavior more immediately responsive to the deceleration contingencies. Under low force on Arrangement 2 the rates of three subjects decelerated on both handswitches but it was immediate in only one case; under high force all six decelerated to zero rate immediately on presentation of the contingency. When responding on a handswitch had no effect on narration intensity deceleration was more immediate and occurred in more subjects under added force. Increased force had a greater effect on preference among the academically retarded subjects than among normals. Under low force when they could do both five looked and listened for the entire session, and one looked continuously but listened only sporadically. Under added force only one subject looked and listened continuously; the sporadic listener stopped listening entirely, while the other four listened unevenly. When they could not do both, under low force two indicated no preference and three chose to look rather than listen. Under high force all five chose to look.
DISCUSSION The results indicate that increasing response-force decelerates rate, even though under a conjugate arrangement a lower rate need not reduce frequency of consequation, since the rate required to maintain maximum consequence intensity can be altered to conform to rate changes. This assures that we are measuring effects of force not of amount of consequation. Increasing response-force requirements enhances the sensitivity and value of the conjugate procedure as an experimental tactic by rendering behavior more immediately responsive to contingency changes. Behavior under such strong experimental control provides an efficient yet sensitive meter for measuring the effects of a range of variables. In this study contingencies were altered every 3-5 min, yet, under added force, behavior accelerated and decelera:ed directly and immediately with the contingency shifts. Such precise behavior control allows the evaluation of many variables within a reasonable time span. Increasing response-force enhances the sensitivity of the conjugate method as a measure of preference. Difference in consequential strength of two narrations, not apparent when response cost was low, were amplified when cost, in the form of response force, was increased. Kansas Vniversity Medical Center, Kansas City, Kansas
MARY MIRA”
REFERENCES LOVITTT. C. (1967) Use of conjugate reinforcement to evaluate the relative reinforcing effects of various narrative forms. J. exp. child Psvchol. 5, 164-171. Lovrrr T. C. (1968) Operant preference of retarded and normal males for rate of narration. Psychol. Rec. 18,205-214.
MIRA M. P. (1968) Individual patterns of looking and listening preferences among learning disabled and normal children. Except. Child. 34, 649-658. MORGANB. and LINDSLEY0. R. (1966) Operant preference for stereophonic over monophonic music. J. Music Therap. 3, 135-143.
NATHANP. E., SCHNELLERP. and LINDSLEY0. R. (1964) Direct measurement psychiatric admission interviews. Behav. Res. & Therapy 2, 49-57.
of communication
* The author wishes to thank Dr. Ogden R. Lindsley who was a source of encouragement ation during the time that this investigation was conducted.
during
and inform-
Rex
k Therapy.
1969. Vol.
7. pp. 331 to 333.
Perpamm
Prus..
Printed
in En!&nd
Effects of response force on conjugate rates (Received 14 December 1968)
Summary-The effects of increased response-force on conjugate response rates were investigated by two procedures which required subjects to work to maintain the intensity of the audio and video channels of a continuously available filmed narration. In the first procedure nine normal boys responded via handswitches requiring 600 g of force to operate while another group of nine boys used handswitches requiring 3000 g of force. The high force group emitted significantly lower rates than the low force group. Added force also increased behavioral responsiveness to two deceleration contingencies. In the second procedure a single group of six learning disabled boys worked under two force conditions. Added force resulted in significant group differences on one of the arrangements of consequences. It also amplified the effect of the deceleration contingencies, and clarified differences in the consequential value of the two narrations. Increasing the response-force requirement heightens the sensitivity of a conjugate analysis of preferences. A CONJUGATE arrangement of consequences provides one of the most sensitive and efficient laboratory methods for analysing consequence preference (Morgan and Lindsley, 1966; Lovitt, 1967,1968; Mira, 1968). Certain factors which may reduce the sensitivity of the procedure by interfering with the effects of the experimental variables include potent social consequences overriding the effects of experimental contingencies, response differentiation deficits in multi-operanda procedures, and delayed or lack of deceleration when responding is inconsequated. One way of increasing the sensitivity of the conjugate procedure is to maximizt the response rate requirement (Nathan, Schneller and Lindsley, 1964). The present study investigated the effects of increasing The effects of the response-force reqiurement as another means of amplifying sensitivity of the procedure increased force requirements on response rates under a conjugate schedule have not been previously reported. This investigation compared the responses of two groups of normal subjects each working under different response-force conditions, and also compared responses of a group of learning disabled children under two different response-force conditions.
METHOD Apparatus Two handswitches
in the experimental room controlled, via traditional circuits, the intensity of the auditory and visual narrations of a 16 mm sound movie which were programmed through two conjugate servo mechanisms. The video portion of the film entered the experimental room through a wall opening behind the subject; the audio channel was presented via headphones. Two cumulative recorders provided the record of the subject’s responses on the handswitches. Subjects The subjects were 18 normal achieving boys, ages 7-l
1, and six academically retarded boys of the same
age range who were enrolled in a special program. Procedure I The 18 normal boys participated
individually in a single I-hr session during which six different arrangements of consequences were presented. Nine boys used handswitches requiring 600 g of force to operate, the other nine used switches requiring 3000 g. The high and low force groups were of comparable age. The six arrangements were as follows: Arrungemcnt 1. The video and audio channels were programmed independently to increase in intensity when the respective hand-switches were activated. Arrungement 2. Video and audio channels each decreased in intensity upon switch activation.
331
332
CASE HISTORIES
AND SHORTER
communications
,-irrafige/~renf 3. Video increased and audio decreased when their respective switches were activated, so that subjects had to press the video switch and simultaneously stop pressing the audio to look and listen. Arrungemenf 4. Video decreased and audio increased when their respective switches were pressed. Arrangenlent 5. Both narrative channels were programmed through one conjugate servo for this and the following arrangement. Activating the operative switch increased video and decreased audio, so that the subject could look or listen but not both. The other switch was inconsequated in that pressing it had no effect on either narration. Arrangement 6. Activating the operative switch increased audio and decreased video narrations. The second switch was inconsequated in that its activation had no effect on either narration, Procedure II
Each of the six academically retarded subjects p~ticipated in two one hour sessions seven to nine months apart. Handswitches requiring 600 g of force were used in one session, 3000 g switches in the other. The arrangements of consequences were similar to Procedure I.
RESULTS Procedure I. Two groups of normals
Increased response-force was associated with significantly lower response rates under all experimental arrangements in which responding increased the intensity of a narration. Despite diminished rates, subjects in the 3000-g group obtained narrations at maximal intensity since the rates required to maintain full intensity, having been functionally predetermined for each subject, were correspondingly lower. Table 1 presents the median response rates based on each subject’s rates during the last three minutes of each arrangement. TABLE 1. GROUP MEDIAN RESPONSERATES UNDER TWO RESPONSEFORCEREQUIREMENTS
mg
3@og
Fisher Exact y value 0~000oooo3 0030017
I
Video switch: increase Audio switch : increase
78 66
32 22
2
Video switch: decrease Audio switch: decrease
0 0
0 0
3
Video switch: increase Audio switch: decrease
105
5
28 0
0@00016 0.15
o-2 0.28
4
Video switch: decrease Audio switch : increase
14 76
0 27
0.19 0.0~019
5
Operative switch: video increase, audio decrease Inconsequated switch
70 36
21 7
0900005
Operative switch: video decrease, audio increase Inconsequated switch
16
44
t 1
6
04005
0.14
0.01
There was a significant (p 0.003)’ difference between the groups in immediacy of response deceleration under Arrangement 2 in which both channels diminished upon responding. In the low force group 38 per cent stopped responding within a few seconds upon institution of the arrangement, while 72 per cent of the high force group immediately decelerated to zero. In the high force group absolute rates under inconsequation were more suppressed (Table 1) and immediacy of complete deceleration significantly mote frequent (p OJJO4) than in the low force group. No low force subject stopped pressing immediately on the nonfunctional switch under Arrangement 5 or 6, while three high force boys decelerated immediately under Arrangement 5 and four did under Arrangement 6. * All probability
figures in this report are based on the Fisher Exact p.
333
CASE HISTORIES AND SHORTER COMML’NICATIONS
Among the normal subjects increased force had a limited effect on preference. Subjects in both groups chose to look and listen simultaneously when they could. When they could not do both, the high force subjects most frequently chose to look (six of the nine). while among the low force group two chose to look and five responded at less than the maximum rate and obtained both narrations, each at diminished intensity. Procedure
II. Same sahjec~s
Increased force diminished absolute rates of all six academically retarded subjects under all contingencies. but the suppression was significant only for Arrangement 2 (p 0,007 for video switch and 0.0046 for audio). Added force also made behavior more immediately responsive to the deceleration contingencies. Under low force on Arrangement 2 the rates of three subjects decelerated on both handswitches but it was immediate in only one case; under high force all six decelerated to zero rate immediately on presentation of the contingency. When responding on a handswitch had no effect on narration intensity deceleration was more immediate and occurred in more subjects under added force. Increased force had a greater effect on preference among the academically retarded subjects than among normals. Under low force when they could do both five looked and listened for the entire session, and one looked continuously but listened only sporadically. Under added force only one subject looked and listened continuously; the sporadic listener stopped listening entirely, while the other four listened unevenly. When they could not do both, under low force two indicated no preference and three chose to look rather than listen. Under high force all five chose to look.
DISCUSSION The results indicate that increasing response-force decelerates rate, even though under a conjugate arrangement a lower rate need not reduce frequency of consequation, since the rate required to maintain maximum consequence intensity can be altered to conform to rate changes. This assures that we are measuring effects of force not of amount of consequation. Increasing response-force requirements enhances the sensitivity and value of the conjugate procedure as an experimental tactic by rendering behavior more immediately responsive to contingency changes. Behavior under such strong experimental control provides an efficient yet sensitive meter for measuring the effects of a range of variables. In this study contingencies were altered every 3-5 min, yet, under added force, behavior accelerated and decelera:ed directly and immediately with the contingency shifts. Such precise behavior control allows the evaluation of many variables within a reasonable time span. Increasing response-force enhances the sensitivity of the conjugate method as a measure of preference. Difference in consequential strength of two narrations, not apparent when response cost was low, were amplified when cost, in the form of response force, was increased. Kansas Vniversity Medical Center, Kansas City, Kansas
MARY MIRA”
REFERENCES LOVITTT. C. (1967) Use of conjugate reinforcement to evaluate the relative reinforcing effects of various narrative forms. J. exp. child Psvchol. 5, 164-171. Lovrrr T. C. (1968) Operant preference of retarded and normal males for rate of narration. Psychol. Rec. 18,205-214.
MIRA M. P. (1968) Individual patterns of looking and listening preferences among learning disabled and normal children. Except. Child. 34, 649-658. MORGANB. and LINDSLEY0. R. (1966) Operant preference for stereophonic over monophonic music. J. Music Therap. 3, 135-143.
NATHANP. E., SCHNELLERP. and LINDSLEY0. R. (1964) Direct measurement psychiatric admission interviews. Behav. Res. & Therapy 2, 49-57.
of communication
* The author wishes to thank Dr. Ogden R. Lindsley who was a source of encouragement ation during the time that this investigation was conducted.
during
and inform-