A Comparison of the Effects of Vicariously Instigated Classical Conditioning and Direct Classical Conditioning Procedures Awu~t I. SILVER .NO TOMMY S. GRECO
The Department o[ Psychology, University o[ Georgia, Athens, Georgia and the Department o[ Psychology, Purdue University, Fort Wayne, Indiana Abstract-Two groups of Ss received either two or 16 paired classical conditioning trials beyond the peak CR. A third group received the same stimuli as in the 16 postpeak condition but in an unpaired and random order. The stimuli in all three groups were delivered directly to S. Subsequently, all three groups, including a fourth which was not given any prior direct classical conditioning, were exposed to vicariously instigated classical conditioning. This consisted of having S observe someone (model) employed by E who received the same CS as was delivered during direct conditioning. The CS was paired with the feigned arm movement of the model, simulating a reaction to shock. This vicarious classical conditioning procedure when compared to direct classical conditioning resulted in smaller GSR magnitudes for both the CRs and UCRs. Previous experience with direct classical conditioning seems to have had an attenuating effect on GSR magnitude during the vicarious situation. A postexperimental questionnaire tended to support the results, and the relationship between the present study and current classical conditioning theory" is discussed.
DIPdgCT CLASSICAL CONDITIONING involves presenting paired presentations of a conditional stimulus (CS) and an unconditional stimulus ( U C S ) to S. Using the Galvanic Skin Response (GSR) as an indicator of conditioning, the conditional response ( C R ) has been shown to increase in m a g n i t u d e a n d reach a peak early during acquisition, followed by attenuation on subsequent trials. A decrease in the m a g n i t u d e of the response m a d e to the UCS, or Portions of these data were presented at the 1973 annual meeting of the Midwestern Psychological Association, Chicago, Illinois. Reprint requests to: Avrum I. Silver, Department of Psychology, University of Georgia, Athens, Georgia 30602. 216
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diminution of the unconditional response (UCR), accompanies CR attenuation (Kimmel, 1966). Vicariously instigated classical conditioning requires S to observe a model receiving paired CS-UCS presentations. In many studies including the present one, the UCS is not delivered to the model, rather a feigned UCR movement of the model's arm is paired with the CS. A record is made of the GSRs elicited by S to the CS and UCS the model supposedly receiving. The CS is audible to both the S and the model, with neither receiving the UCS. Although a number of investigators have examined vicarious classical conditioning (e.g., Bandura and Rosenthal, 1966; Craig and Lowery, 1969), none have looked at characteristics already well documented for direct classical conditioning, namely CR attenuation and UCR diminution. The present study attempted to examine these characteristics in a vicarious paradigm. Differences in magnitude of responding between vicarious and direct procedures were also examined. Studies investigating these differences have not used a classical conditioning paradigm. Craig (1968) and Craig & Wood (1969) looked at GSRs Ss made to immersing their hands in either cold water or a cold brine solution. These responses were compared to ones made by Ss who observed models immersing their hands in the same solutions. The results indicated that the direct conditions produced significantly more and larger GSR.s than the vicarious conditions. The present research used a classical conditioning paradigm and electrical shock as the UCS. In this way, through the use of a more precise aversive stimulus, vicarious and direct Pavlovian procedures were compared. Finally, the present study also looked at the effects of prior direct classical conditioning on the CRs and UCRs of a subsequent vicariously instigated classical conditioning procedure. Craig (1968) and Craig and Wood (1969) in the same studies described above demonstrated that prior aversive experience led to less GSR activity during vicarious arousal. Once again, however, no attempt was made to use a classical conditioning paradigm and a rather poorly controlled method of delivering aversive stimulation was used. The various comparisons were examined using two groups who received direct classical conditioning training, one receiving two trials past the peak CR (Group I ) and the other receiving 16 trials past the peak CR (Group II). A third group of Ss (Group III) were matched to Ss in Group II as to the number of presentations of the UCS and CS, but received them in an unpaired and random order. This control group provided a baseline for demonstrating conditioning during the direct phase of acquisition. A fourth group (Group IV) did not receive any direct experience. All groups then
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received vicarious training in which S watched the model receive the CS paired with the faked UCR movement of the model's arm. It was predicted that Ss in direct classical conditioning would make larger CRs and UCRs than their counterparts in the vicarious conditions. Therefore, any peak CR occurring for the vicarious Ss would be greatly diminished, and CR attenuation and UCR diminution, while being present, would also be less obvious. An hypothesis was formed, based in part upon studies by Silver and Kimmel (1969) and Schramm and Kimmel (1971). These studies demonstrated that few acquisition trials result in both strong conditioning and strong resistance to extinction. It was found that Ss receiving only two trials past the peak CR showed significantly greater resistance to extinction than Ss who received 16 trials beyond the peak. Since this peak phase of conditioning or period of heightened activity is followed by reduced activity or CR attenuation, it was hypothesized that terminating acquisition either at the beginning of or after this period of reduced activity during the direct phase of the present study would be reflected in the subsequent vicarious situation. Specifically, it was predicted that Ss in Group I who received two trials past the peak CR for direct classical conditioning would show greater CR and UCR magnitudes during the vicarious phase of the experiment than Ss who received 16 trials past the peak. Also, since it was expected that CR attenuation would have a decremental effect upon the response magnitudes during tile subsequent vicarious procedure, Ss with no prior direct experience should show little or no difference in magnitude of responding during vicarious conditioning when compared to Ss who received two direct pestpeak trials. However, it was expected that Ss in the 16 pestpeak group would make significantly smaller CRs and UCRs during vicarious training than Ss who did not receive any prior direct experience. A questionnaire was given at the end of the experiment which dealt with S's attitude towards the model. Embedded in the questionnaire was an item asking Ss to determine the amount of discomfort they experienced while watching someone else receive shock. It was hypothesized that Ss in Group II would experience the least amount of discomfort, with Ss in all the other groups experiencing significantly more discomfort. Method
Subjects and Design Forty-eight undergraduate students, enrolled in an introductoD, psychology class at the University of Georgia, volunteered to participate in the experiment. They were randomly assigned to one
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of four groups, with 12 Ss in each group. Three of the groups had equal numbers of males and females, while Group I had seven males and five females. The Ss received three presentations of the UCS in increasing intensities of 1.0, 2.5, and 4.0-mA d:c (i.e., sensitization), followed by 12 habituation trials of the CS (Silver, 1973). They were then divided into four groups, two of them differing in the number of postpeak classical conditioning trials they received. A third group was given unpaired presentations o,f the CS and UCS, the number of CS and UCS presentations for each S being matched to the total number of trials Ss received in the 16 postpeak group. Group IV did not receive any classical conditioning; insteod, each S waited for a period of time matched to the amount of time it took each S to receive paired CS-UCS trials in the 16 post-peak group. Subsequently, all four groups received 10 vicarious acquisition trials. One of two female models employed by E sat in the same booth with S during the entire experiment. Each model shared the booth with an equal number of males and females for each group, except for Group I where three females and three males served with one, and two females and four males served with the other. Up until the end of the classical conditioning procedure, the lights in the booth were kept off and the models were instructed to remain quiet for this first part of the experiment. The lights were then turned on enabling S to see the model, which was then followed by the presentation of the CS once again. The CS was then paired with the feigned movement of the model's right arm.
Apparatus and Materials The S was seated in a dark, sound attenuated chamber.* The chair used to seat S was a standard office chair with armrests on which S was instructed to keep his arms during the experimental session. E was able to communicate at all times with S through a two-way intercom. The CS was a 39 db (physical reference), 1,000 Hz tone of 5.0see duration delivered from an RCA audio generator model WA-44C to a Quam 8A21PA 270512 speaker placed on an equal distance of three feet from the model and S. The electric shock (UCS) was delivered five seconds after the onset of the CS v/a copper electrodes attached to the S's right forearm. It was produced by an Argoneaut Associates constant current amplifier, model LRA046, with an intensity of 4.0 mA de and duration of .1 see. The duration of both the CS and the UCS was controlled by two Hunter timers, type * E. A. Lindgren Associates, Inc., Model 12.
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111-C3. Skin resistance was picked up from the palm and back of S's left hand by zinc sulfate electrodes in lucite cups filled with electrode jelly. The GSR was amplified by an Electronics Laboratories, model 308C amplifier and recorded on a Texas Instruments Company Recti-Riter with a paper speed of .127 cm/sec. Illumination used during the vicarious portion of the experiment was furnished by three 40 watt bulbs attached to a pole lamp placed 2~ feet away from both the S and the model. At the end of the session a questionnaire was handed out concerned with S's attitude toward the study. Procedure. The designated model appeared at the laboratory at the same time signed up for by S. Upon arrival, both were introduced, given a brief introductory statement about the study and were sent to the laboratory to wash their hands. Upon return, they were seated in the booth, GSR and UCS electrodes affixed, lights turned out and chamber door closed. Instructions were then given v/a the intercom revealing that the study is concerned with the recording of physiological responses made to ( 1 ) tones and mild electrical shocks that they will receive and, (2) some social observations that they will be asked to engage in. They were also informed that at some point the lights in the booth would be turned on and the S designated "A" was to observe the reactions of S "B", the latter really being the model. Ss were also told that no shock would be given to S "A" after the lights were turned on. This was done to prevent S from continuing to expect more shocks, since this would have been confounded with the purpose of the study, namely recording of responses S makes when observing others receiving paired stimuli. S was finally asked to remain alert and attentive, and severe and unnecessary movements were to be avoided. Upon termination of the experiment, Ss were asked to fill o u t the questionnaire, thanked for participating and asked not to discuss the experiment with ochers.
Results The GSR was transformed to units of log conductance for analysis using the formula: log (1/resistance, peak)-log (1/resistance, base). A response was designated a CR ff it occurred within the interval of 1.5 and 6.5 sec following CS onset, and a UCR was recorded if it occurred between 1.5 and 2.5 sec following UCS onset. The criterion for a response was 1 per cent of the base resistante value, the latter being determined 1.0 sec prior to CS or UCS onset. Base resistance values did not differ significantly from one another during acquisition.
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AND
DIRECT
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.036 -
: direct ,vicarious
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Fro. 1. Mean magnitude of GSR for both CRs
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The 2 and 16 post-peak groups demonstrated no statistical dif. ference between them during the direct phase of conditioning. Therefore, their CRs were combined and compared to those responses made to the CS in the unpaired control group. This test for conditioning during the first phase of the experiment was carried out for the first four acquisition trials, for to go beyond four trials would involve omitting Ss who reached a peak CR in two trials. The data revealed that Ss in the paired group made significantly larger CRs than Ss in the control group. An analysis of variance showed a significant main effect for groups, F (1,22) = 10.1, P < 0.005 and a significant Trials X Groups interaction, F (3,66) = 8.0, P < 0.001. The main effect for trials was also significant, F (3,66) -- 7.5, P < 0.005. A comparison of the effects between a direct classical conditioning procedure and a vicariously instigated procedure are illustrated in Figure 1. The data reflect the magnitude of the response made to the CS during the vicarious portion of the study and the magnitude of the CR for the 16 post-peak group during the direct phase of the experiment. The vicarious group used in this comparison was the one that received no prior experience with direct classical conditioning. Ten trials of vicarious training was all that was given and therefore had to be compared to the first ten trials for the direct classical conditioning group in Figure 1. Direct conditioning
222
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TRIALS resulted in larger responses being made to the CS. While both groups exhibited a peak effect, it occurred later and was somewhat attenuated for the vicarious condition. The magnitude values tended to approach one another later in acquisition, although except for Trial I the CR values for the direct condition never did fall below those for the vicarious group. The Trials X Groups interaction was significant, F (9,198) -- 2.95, P < 0.0005, as was the main effect for trials, F (9,198)--6.17, P < 0.001. Using the same groups, Figure 1 also shows comparisons for the UCRs. Once again, the size of the responses for'the direct condition are larger than those for the vicarious situation. Also, there appears to be an overall diminution effect for both groups, although more pronounced for Ss who received direct stimulation. The differences between the two groups were statistically significant, F (1,22)--- 14.4, P < 0.001, as were the main effect for trials, F ( 9 , 1 9 8 ) = 10.7, P < 0.001 and the Trials X Groups interaction, F (9,198) = 3.2, P < 0.05. Figure 2 presents the data concenaing the effects of previous experience with direct classical conditioning on the subsequent vicarious situation. Groups that received 2 and 16 trials past the peak during direct training along with the group that received no direct experience were used in the present comparison. The data
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VICARIOUS AN'D D IR EC T C O N D I T I O N I N G
TABLE 1. Means Reflecting the Amount of Discomfort Experienced by S while Watching A Model React to Shock for Groups with Different Amounts of Prior Classical Conditioning Training Amount of Prior Classical Conditioning Training 0
2
16
M
SD
M
SD
M
SD
3.3
1.1
2.9
1.6
1.9
1.0
Note. -- Numbers indicating amount of prior training represent the following; 0 = no previous training, 2 = 2 trials beyond peak CR, 16 = 16 trials beyond peak CR.
for the ten vicarious classical conditioning trials are presented. On each trial except the first, the magnitude of the CRs for the two groups that received little or no prior conditioning were larger than the group that received 16 trials past the peak. However, an analysis of variance did not support these differences. The data for the UCRs during the vicarious phase are also presented in Figure 2 and the relationship here resembles that obtained for the CR data. The largest responses were produced by Ss in the two groups that received either no previous classical conditioning or only two trials past the peak CR. This was supported by the results of analysis of variance with the Trials X Groups interaction being significant, F (18,297) = 1.76, P < 0.05. A significant decrease in the magnitude of the UCtls took place for all groups as evidenced by the main effect for trials, F (18,297) = 11.4, P < 0.001. The responses to the questionnaire concerning S's attitude towards the model revealed no evidence that S knew the model was working for E. Embedded in the questionnaire was the item asking S to determine on a five point scale the amount of discomfort they experienced watching someone else receive shock. Table 1 reveals that Ss in the group that received no previous experience with classical conditioning experienced the most discomfort while watching the model react to shock. Ss who previously received two trials past the peak also experienced a considerable amount of discomfort. However, the group that was exposed to 16 postpeak trials during direct conditioning were the least uncomfortable while watching the model. The analysis of variance comparing the three groups was significant, F (2,31) = 4.3, P < 0.025.* * Two Ss failed to respond to the questionnaire, one from Group I and one from Group II.
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Discussion The vicariously instigated classical conditioning procedure resulted in significantly smaller CRs and UCRs than that produced by direct classical conditioning. However, there are some similarities that did result from the two procedures. The magnitude of the CRs for the vicarious group that received no prior training did reach a peak early in acquisition. Also, UCR diminution for the same group seems to have taken place, but in both cases, the extent to which these occurred was not as great as that observed during direct classical conditioning. It appears, at least as measured by the GSR, that the vicarious situation is a less effective learning process than the direct situation. There appears to be some evidence for an attenuated effect on vicarious responding as a result of previous exposure to direct classical conditioning. Larger CRs were elicited by Ss who had little or no previous experience with classical conditioning on each of the ten vicarious trials except the first, although there was no statistical support for this relationship. The general decremental effect on all responding during vicarious conditioning could have contributed to the inability of statistics to detect significant differences. A similar relationship existed with the UCR data although in this case the results were statistically significant. The CR and UCR data shed some light on direct classical conditioning of the GSR in that Ss who received little (two trials past the peak) or no direct classical conditioning appeared to be more responsive during vicarious training. Sixteen trials past the peak CR results in considerable CE attenuation which apparently had a decremental effect upon subsequent vicarious training. This tends to be in line with current classical conditioning theories that emphasize an inhibitor>' mechanism in relation to the UCR (Kimmell, 1966; Perkins, 1968) or learned helplessness ( Rescorla and Solomon, 1967 ), both of which come with extended trials. While both positions are different, eacll would predict the above results concerning the effects of prior experience. Consistent with this interpretation are the findings obtained with the questionnaire. Ss who received no previous training or only two trials past the peak expressed more discomfort while watching the model receiving what they thought were shocks than Ss who received 16 trials beyond peak CR. So any effects of CR attenuation seem to have been reflected in the amount of discomfort Ss experienced while watching the model. Some conclusions about vicariously instigated classical conditioning can be drawn. The data seem to suggest that there are some similarities between the effects of both procedures, although some-
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what attenuated for the vicarious situation. There was a peak CR response and subsequent CR attenuation for both situations, as well as UCR diminution. However, before firm conclusions can be m a d e concerning the relationship b e t w e e n the two procedures, other factors such as CS-UCS interval, delay vs trace paradigms, and UCS intensity have to be examined.
References Bandura, A., and Rosenthal, T. L.: Vicarious classical conditioning as a function of arousal level. ]. Per. Soc. Psychol. 3:54-62, 1966. Craig, K. D.: Physiological arousal as a function of imagined, vicarious, and direct stress experiences. 1. Abnorm. Psychol. 73:513-520, 1968. Craig, K. D., and Lower),, H. ].: Heart-rate components of conditioned vicarious autonomic responses. ]. Per. Soc. Psychol. 11:381-387, 1969. Kimmel, H. D.: Inhibition of the unconditioned response in classical conditioning. Psychol. Rev. 73:232-240, 1966. Perkins, E. C., Jr.: An analysis of the concept of reinforcement. Psgchol. Rev. 75:155-172, 1968. Rescorla, R. A., and Solomon, R. L.: Two-process learning theory: Relationships between Pavlovian conditioning and instrumental learning. Psychol. Rev. 75:151-182, 1967. Schramm, C. F., and Kimmel, H. D.: Resistance to extinction in GSR conditioning following different numbers of postpeak acquisition trials. J. Exp. P~chol. 84:239-243, 1970. Silver, A. I.: Effects of prior CS presentations on classical conditioning of the GSR. Psychophysiology 10:583-588, 1973. Silver, A. I., and Kimmel, H. D.: Resistance to extinction in classical GSR conditioning as a function of acquisition trials beyond peak CR size. Psychon. Sci 14:53-54, 1969.
The Department o[ Psychology, University o[ Georgia, Athens, Georgia and the Department o[ Psychology, Purdue University, Fort Wayne, Indiana Abstract-Two groups of Ss received either two or 16 paired classical conditioning trials beyond the peak CR. A third group received the same stimuli as in the 16 postpeak condition but in an unpaired and random order. The stimuli in all three groups were delivered directly to S. Subsequently, all three groups, including a fourth which was not given any prior direct classical conditioning, were exposed to vicariously instigated classical conditioning. This consisted of having S observe someone (model) employed by E who received the same CS as was delivered during direct conditioning. The CS was paired with the feigned arm movement of the model, simulating a reaction to shock. This vicarious classical conditioning procedure when compared to direct classical conditioning resulted in smaller GSR magnitudes for both the CRs and UCRs. Previous experience with direct classical conditioning seems to have had an attenuating effect on GSR magnitude during the vicarious situation. A postexperimental questionnaire tended to support the results, and the relationship between the present study and current classical conditioning theory" is discussed.
DIPdgCT CLASSICAL CONDITIONING involves presenting paired presentations of a conditional stimulus (CS) and an unconditional stimulus ( U C S ) to S. Using the Galvanic Skin Response (GSR) as an indicator of conditioning, the conditional response ( C R ) has been shown to increase in m a g n i t u d e a n d reach a peak early during acquisition, followed by attenuation on subsequent trials. A decrease in the m a g n i t u d e of the response m a d e to the UCS, or Portions of these data were presented at the 1973 annual meeting of the Midwestern Psychological Association, Chicago, Illinois. Reprint requests to: Avrum I. Silver, Department of Psychology, University of Georgia, Athens, Georgia 30602. 216
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diminution of the unconditional response (UCR), accompanies CR attenuation (Kimmel, 1966). Vicariously instigated classical conditioning requires S to observe a model receiving paired CS-UCS presentations. In many studies including the present one, the UCS is not delivered to the model, rather a feigned UCR movement of the model's arm is paired with the CS. A record is made of the GSRs elicited by S to the CS and UCS the model supposedly receiving. The CS is audible to both the S and the model, with neither receiving the UCS. Although a number of investigators have examined vicarious classical conditioning (e.g., Bandura and Rosenthal, 1966; Craig and Lowery, 1969), none have looked at characteristics already well documented for direct classical conditioning, namely CR attenuation and UCR diminution. The present study attempted to examine these characteristics in a vicarious paradigm. Differences in magnitude of responding between vicarious and direct procedures were also examined. Studies investigating these differences have not used a classical conditioning paradigm. Craig (1968) and Craig & Wood (1969) looked at GSRs Ss made to immersing their hands in either cold water or a cold brine solution. These responses were compared to ones made by Ss who observed models immersing their hands in the same solutions. The results indicated that the direct conditions produced significantly more and larger GSR.s than the vicarious conditions. The present research used a classical conditioning paradigm and electrical shock as the UCS. In this way, through the use of a more precise aversive stimulus, vicarious and direct Pavlovian procedures were compared. Finally, the present study also looked at the effects of prior direct classical conditioning on the CRs and UCRs of a subsequent vicariously instigated classical conditioning procedure. Craig (1968) and Craig and Wood (1969) in the same studies described above demonstrated that prior aversive experience led to less GSR activity during vicarious arousal. Once again, however, no attempt was made to use a classical conditioning paradigm and a rather poorly controlled method of delivering aversive stimulation was used. The various comparisons were examined using two groups who received direct classical conditioning training, one receiving two trials past the peak CR (Group I ) and the other receiving 16 trials past the peak CR (Group II). A third group of Ss (Group III) were matched to Ss in Group II as to the number of presentations of the UCS and CS, but received them in an unpaired and random order. This control group provided a baseline for demonstrating conditioning during the direct phase of acquisition. A fourth group (Group IV) did not receive any direct experience. All groups then
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received vicarious training in which S watched the model receive the CS paired with the faked UCR movement of the model's arm. It was predicted that Ss in direct classical conditioning would make larger CRs and UCRs than their counterparts in the vicarious conditions. Therefore, any peak CR occurring for the vicarious Ss would be greatly diminished, and CR attenuation and UCR diminution, while being present, would also be less obvious. An hypothesis was formed, based in part upon studies by Silver and Kimmel (1969) and Schramm and Kimmel (1971). These studies demonstrated that few acquisition trials result in both strong conditioning and strong resistance to extinction. It was found that Ss receiving only two trials past the peak CR showed significantly greater resistance to extinction than Ss who received 16 trials beyond the peak. Since this peak phase of conditioning or period of heightened activity is followed by reduced activity or CR attenuation, it was hypothesized that terminating acquisition either at the beginning of or after this period of reduced activity during the direct phase of the present study would be reflected in the subsequent vicarious situation. Specifically, it was predicted that Ss in Group I who received two trials past the peak CR for direct classical conditioning would show greater CR and UCR magnitudes during the vicarious phase of the experiment than Ss who received 16 trials past the peak. Also, since it was expected that CR attenuation would have a decremental effect upon the response magnitudes during tile subsequent vicarious procedure, Ss with no prior direct experience should show little or no difference in magnitude of responding during vicarious conditioning when compared to Ss who received two direct pestpeak trials. However, it was expected that Ss in the 16 pestpeak group would make significantly smaller CRs and UCRs during vicarious training than Ss who did not receive any prior direct experience. A questionnaire was given at the end of the experiment which dealt with S's attitude towards the model. Embedded in the questionnaire was an item asking Ss to determine the amount of discomfort they experienced while watching someone else receive shock. It was hypothesized that Ss in Group II would experience the least amount of discomfort, with Ss in all the other groups experiencing significantly more discomfort. Method
Subjects and Design Forty-eight undergraduate students, enrolled in an introductoD, psychology class at the University of Georgia, volunteered to participate in the experiment. They were randomly assigned to one
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of four groups, with 12 Ss in each group. Three of the groups had equal numbers of males and females, while Group I had seven males and five females. The Ss received three presentations of the UCS in increasing intensities of 1.0, 2.5, and 4.0-mA d:c (i.e., sensitization), followed by 12 habituation trials of the CS (Silver, 1973). They were then divided into four groups, two of them differing in the number of postpeak classical conditioning trials they received. A third group was given unpaired presentations o,f the CS and UCS, the number of CS and UCS presentations for each S being matched to the total number of trials Ss received in the 16 postpeak group. Group IV did not receive any classical conditioning; insteod, each S waited for a period of time matched to the amount of time it took each S to receive paired CS-UCS trials in the 16 post-peak group. Subsequently, all four groups received 10 vicarious acquisition trials. One of two female models employed by E sat in the same booth with S during the entire experiment. Each model shared the booth with an equal number of males and females for each group, except for Group I where three females and three males served with one, and two females and four males served with the other. Up until the end of the classical conditioning procedure, the lights in the booth were kept off and the models were instructed to remain quiet for this first part of the experiment. The lights were then turned on enabling S to see the model, which was then followed by the presentation of the CS once again. The CS was then paired with the feigned movement of the model's right arm.
Apparatus and Materials The S was seated in a dark, sound attenuated chamber.* The chair used to seat S was a standard office chair with armrests on which S was instructed to keep his arms during the experimental session. E was able to communicate at all times with S through a two-way intercom. The CS was a 39 db (physical reference), 1,000 Hz tone of 5.0see duration delivered from an RCA audio generator model WA-44C to a Quam 8A21PA 270512 speaker placed on an equal distance of three feet from the model and S. The electric shock (UCS) was delivered five seconds after the onset of the CS v/a copper electrodes attached to the S's right forearm. It was produced by an Argoneaut Associates constant current amplifier, model LRA046, with an intensity of 4.0 mA de and duration of .1 see. The duration of both the CS and the UCS was controlled by two Hunter timers, type * E. A. Lindgren Associates, Inc., Model 12.
220
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111-C3. Skin resistance was picked up from the palm and back of S's left hand by zinc sulfate electrodes in lucite cups filled with electrode jelly. The GSR was amplified by an Electronics Laboratories, model 308C amplifier and recorded on a Texas Instruments Company Recti-Riter with a paper speed of .127 cm/sec. Illumination used during the vicarious portion of the experiment was furnished by three 40 watt bulbs attached to a pole lamp placed 2~ feet away from both the S and the model. At the end of the session a questionnaire was handed out concerned with S's attitude toward the study. Procedure. The designated model appeared at the laboratory at the same time signed up for by S. Upon arrival, both were introduced, given a brief introductory statement about the study and were sent to the laboratory to wash their hands. Upon return, they were seated in the booth, GSR and UCS electrodes affixed, lights turned out and chamber door closed. Instructions were then given v/a the intercom revealing that the study is concerned with the recording of physiological responses made to ( 1 ) tones and mild electrical shocks that they will receive and, (2) some social observations that they will be asked to engage in. They were also informed that at some point the lights in the booth would be turned on and the S designated "A" was to observe the reactions of S "B", the latter really being the model. Ss were also told that no shock would be given to S "A" after the lights were turned on. This was done to prevent S from continuing to expect more shocks, since this would have been confounded with the purpose of the study, namely recording of responses S makes when observing others receiving paired stimuli. S was finally asked to remain alert and attentive, and severe and unnecessary movements were to be avoided. Upon termination of the experiment, Ss were asked to fill o u t the questionnaire, thanked for participating and asked not to discuss the experiment with ochers.
Results The GSR was transformed to units of log conductance for analysis using the formula: log (1/resistance, peak)-log (1/resistance, base). A response was designated a CR ff it occurred within the interval of 1.5 and 6.5 sec following CS onset, and a UCR was recorded if it occurred between 1.5 and 2.5 sec following UCS onset. The criterion for a response was 1 per cent of the base resistante value, the latter being determined 1.0 sec prior to CS or UCS onset. Base resistance values did not differ significantly from one another during acquisition.
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.036 -
: direct ,vicarious
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quisition
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The 2 and 16 post-peak groups demonstrated no statistical dif. ference between them during the direct phase of conditioning. Therefore, their CRs were combined and compared to those responses made to the CS in the unpaired control group. This test for conditioning during the first phase of the experiment was carried out for the first four acquisition trials, for to go beyond four trials would involve omitting Ss who reached a peak CR in two trials. The data revealed that Ss in the paired group made significantly larger CRs than Ss in the control group. An analysis of variance showed a significant main effect for groups, F (1,22) = 10.1, P < 0.005 and a significant Trials X Groups interaction, F (3,66) = 8.0, P < 0.001. The main effect for trials was also significant, F (3,66) -- 7.5, P < 0.005. A comparison of the effects between a direct classical conditioning procedure and a vicariously instigated procedure are illustrated in Figure 1. The data reflect the magnitude of the response made to the CS during the vicarious portion of the study and the magnitude of the CR for the 16 post-peak group during the direct phase of the experiment. The vicarious group used in this comparison was the one that received no prior experience with direct classical conditioning. Ten trials of vicarious training was all that was given and therefore had to be compared to the first ten trials for the direct classical conditioning group in Figure 1. Direct conditioning
222
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TRIALS resulted in larger responses being made to the CS. While both groups exhibited a peak effect, it occurred later and was somewhat attenuated for the vicarious condition. The magnitude values tended to approach one another later in acquisition, although except for Trial I the CR values for the direct condition never did fall below those for the vicarious group. The Trials X Groups interaction was significant, F (9,198) -- 2.95, P < 0.0005, as was the main effect for trials, F (9,198)--6.17, P < 0.001. Using the same groups, Figure 1 also shows comparisons for the UCRs. Once again, the size of the responses for'the direct condition are larger than those for the vicarious situation. Also, there appears to be an overall diminution effect for both groups, although more pronounced for Ss who received direct stimulation. The differences between the two groups were statistically significant, F (1,22)--- 14.4, P < 0.001, as were the main effect for trials, F ( 9 , 1 9 8 ) = 10.7, P < 0.001 and the Trials X Groups interaction, F (9,198) = 3.2, P < 0.05. Figure 2 presents the data concenaing the effects of previous experience with direct classical conditioning on the subsequent vicarious situation. Groups that received 2 and 16 trials past the peak during direct training along with the group that received no direct experience were used in the present comparison. The data
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VICARIOUS AN'D D IR EC T C O N D I T I O N I N G
TABLE 1. Means Reflecting the Amount of Discomfort Experienced by S while Watching A Model React to Shock for Groups with Different Amounts of Prior Classical Conditioning Training Amount of Prior Classical Conditioning Training 0
2
16
M
SD
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SD
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3.3
1.1
2.9
1.6
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Note. -- Numbers indicating amount of prior training represent the following; 0 = no previous training, 2 = 2 trials beyond peak CR, 16 = 16 trials beyond peak CR.
for the ten vicarious classical conditioning trials are presented. On each trial except the first, the magnitude of the CRs for the two groups that received little or no prior conditioning were larger than the group that received 16 trials past the peak. However, an analysis of variance did not support these differences. The data for the UCRs during the vicarious phase are also presented in Figure 2 and the relationship here resembles that obtained for the CR data. The largest responses were produced by Ss in the two groups that received either no previous classical conditioning or only two trials past the peak CR. This was supported by the results of analysis of variance with the Trials X Groups interaction being significant, F (18,297) = 1.76, P < 0.05. A significant decrease in the magnitude of the UCtls took place for all groups as evidenced by the main effect for trials, F (18,297) = 11.4, P < 0.001. The responses to the questionnaire concerning S's attitude towards the model revealed no evidence that S knew the model was working for E. Embedded in the questionnaire was the item asking S to determine on a five point scale the amount of discomfort they experienced watching someone else receive shock. Table 1 reveals that Ss in the group that received no previous experience with classical conditioning experienced the most discomfort while watching the model react to shock. Ss who previously received two trials past the peak also experienced a considerable amount of discomfort. However, the group that was exposed to 16 postpeak trials during direct conditioning were the least uncomfortable while watching the model. The analysis of variance comparing the three groups was significant, F (2,31) = 4.3, P < 0.025.* * Two Ss failed to respond to the questionnaire, one from Group I and one from Group II.
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Discussion The vicariously instigated classical conditioning procedure resulted in significantly smaller CRs and UCRs than that produced by direct classical conditioning. However, there are some similarities that did result from the two procedures. The magnitude of the CRs for the vicarious group that received no prior training did reach a peak early in acquisition. Also, UCR diminution for the same group seems to have taken place, but in both cases, the extent to which these occurred was not as great as that observed during direct classical conditioning. It appears, at least as measured by the GSR, that the vicarious situation is a less effective learning process than the direct situation. There appears to be some evidence for an attenuated effect on vicarious responding as a result of previous exposure to direct classical conditioning. Larger CRs were elicited by Ss who had little or no previous experience with classical conditioning on each of the ten vicarious trials except the first, although there was no statistical support for this relationship. The general decremental effect on all responding during vicarious conditioning could have contributed to the inability of statistics to detect significant differences. A similar relationship existed with the UCR data although in this case the results were statistically significant. The CR and UCR data shed some light on direct classical conditioning of the GSR in that Ss who received little (two trials past the peak) or no direct classical conditioning appeared to be more responsive during vicarious training. Sixteen trials past the peak CR results in considerable CE attenuation which apparently had a decremental effect upon subsequent vicarious training. This tends to be in line with current classical conditioning theories that emphasize an inhibitor>' mechanism in relation to the UCR (Kimmell, 1966; Perkins, 1968) or learned helplessness ( Rescorla and Solomon, 1967 ), both of which come with extended trials. While both positions are different, eacll would predict the above results concerning the effects of prior experience. Consistent with this interpretation are the findings obtained with the questionnaire. Ss who received no previous training or only two trials past the peak expressed more discomfort while watching the model receiving what they thought were shocks than Ss who received 16 trials beyond peak CR. So any effects of CR attenuation seem to have been reflected in the amount of discomfort Ss experienced while watching the model. Some conclusions about vicariously instigated classical conditioning can be drawn. The data seem to suggest that there are some similarities between the effects of both procedures, although some-
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what attenuated for the vicarious situation. There was a peak CR response and subsequent CR attenuation for both situations, as well as UCR diminution. However, before firm conclusions can be m a d e concerning the relationship b e t w e e n the two procedures, other factors such as CS-UCS interval, delay vs trace paradigms, and UCS intensity have to be examined.
References Bandura, A., and Rosenthal, T. L.: Vicarious classical conditioning as a function of arousal level. ]. Per. Soc. Psychol. 3:54-62, 1966. Craig, K. D.: Physiological arousal as a function of imagined, vicarious, and direct stress experiences. 1. Abnorm. Psychol. 73:513-520, 1968. Craig, K. D., and Lower),, H. ].: Heart-rate components of conditioned vicarious autonomic responses. ]. Per. Soc. Psychol. 11:381-387, 1969. Kimmel, H. D.: Inhibition of the unconditioned response in classical conditioning. Psychol. Rev. 73:232-240, 1966. Perkins, E. C., Jr.: An analysis of the concept of reinforcement. Psgchol. Rev. 75:155-172, 1968. Rescorla, R. A., and Solomon, R. L.: Two-process learning theory: Relationships between Pavlovian conditioning and instrumental learning. Psychol. Rev. 75:151-182, 1967. Schramm, C. F., and Kimmel, H. D.: Resistance to extinction in GSR conditioning following different numbers of postpeak acquisition trials. J. Exp. P~chol. 84:239-243, 1970. Silver, A. I.: Effects of prior CS presentations on classical conditioning of the GSR. Psychophysiology 10:583-588, 1973. Silver, A. I., and Kimmel, H. D.: Resistance to extinction in classical GSR conditioning as a function of acquisition trials beyond peak CR size. Psychon. Sci 14:53-54, 1969.
