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Part VII: Questions from the audience
510
hhRTIN E. P. SEUGMAN and JAY M. WEISS
PART
VII:
QUESTIONS
FROM
THE
AUDIENCE
F. KEHOE,VP1 AND SU: I’d like to address this to both of you. You may decide for yourselves who will respond. If learning did take place in the nose-poke task, what would the learning curve look like and how could you empirically distinguish learning from accidental responding? DR. WEISS: Maybe the best thing is for me to respond to that ui.+&uis the two experiments that Marty suggested. We’ve looked at it by using the learning curve as a criterion that some kind of learning has taken place; I’m certainly not above considering that there are a whole host of other ways of determining ‘whether learning is occurring in that experiment. Nevertheless, the learning curve suggests that the animals are, in fact, learning something. I think the second experiment that Marty suggested, in which he delivers noncontingent shocks is more interesting than the first he suggested, assuming that he measures responses over a sufficient number of trials. In the beginning, pre-shocked animals might be better than non-shocked animals because they might simply move forward, but this initial effect should wear off. Over the long term, performance of the nosing task by the pre-shocked animals should not be much different from that of the non-shocked animals. The first experiment Marty suggested, in which he is going to deliver 10 noncontingent shocks prior to training, and then look at what appears afterward, is particularly weak. I think the problem with that is that you’re now giving the animals an uncontrollable shock treatment and you may have effects of that per se which mask the things you want to look at later. So I’d be much more impressed by seeing the results of the second experiment than those of the first. Let me talk for just a second about replicability of the phenomenon. You see, this is the sort of thing that gets me about the learned helplessness argument. Marty often replies to our results by saying, “First, they won’t replicate, but, if they do replicate, we can explain them.” When does the ‘helplessness’ hypothesis become faisifiable? When does one set up an experiment and, based on the results of the study, say the hypothesis does not work? I would say that the duration data has to replicate. If the duration data doesn’t replicate, I’ll withdraw my criticisms of the learned helplessness argument with respect to their rat experiments. The duration data must replicate, in my estimation, and it definitely will.* With respect to the nosing experiment, you have to be very careful with that study. We worked for a long time to get just the right apparatus. The reason we didn’t do some of the crucial studies that you asked about, Marty, is that we, like you, spent 4 or 5 years looking for learned helplessness in the rat. It’s very easy not to replicate somebody else’s experiment by just grabbing a tube and trying it. I’ll tell you right now the animal’s got to be the right size. You’ve really got to work. I’ll be glad to tell the person involved how to replicate the phenomenon. Laughter. DR. SELIGMAN:Let me comment as well. I agree with Jay that the second experiment is a better experiment than the first experiment. There is a third experiment which I think should be done, which I think is a rather crucial experiment. It’s just rather difficult to do. Assuming the reality of the effect, and, assuming that Jay can tell us exactly how to get this effect, the question then becomes: what happens if you hold the motor response easy (in this case, falling into the ‘hole) and again, like the FR-1 with a delay, degrade the contingency without changing motor requirements? If learning is going on and you now make the animal try to learn this with, say, a 3 s delay of shock termination, the helplessness hypothesis predicts that now you should see the performance of these animals deteriorate (the ones who got inescapable shock) because although they’ve got the motor incapacity to do it (if you will, they’ve got the inactivity),
JERARD
* This result has been replicated since this discussion. The reference is: Anisman H., de Catanzaro D. and Remington G. (1978) Escape performance following exposure to inescapable shock. Deficits in motor response maintenance. J. exp. Psychol. Animal Behav. Processes 4, 197-218.
Learned helplessness, physiological change and learned inactivity
511
they’re going to have trouble seeing the connection between falling in the hole and shock going off 3 s later. That would be one way of testing it. But I must take exception to Jay’s point about the logic of “Well, it doesn’t replicate; but, even if it did replicate, we can still explain it. Therefore, the hypothesis is unfalsifiable.” That just doesn’t go through at all. There are all sorts of experiments which don’t differentiate between helplessness and inactivity. Jay has done some of them. Whether or not they are replicable doesn’t apply to that. The falsifiability question is whether or not there are any experiments at all which, if they turned out in a given direction, would make us give up the learned helplessness hypothesis. I listed five of those for you. DR. WEISS: But all of those experiments have already been done. DR. SELIGMAN:The question is, in principle, falsifiable, though. That’s the logic of the philosophy of science as I understand it. DR. WEISS: Yes, that is true. DR. SELIGMAN:I think the evidence is already in, basically. FREYAWEIZENBAUM,VP1 AND SU: Jay, I know you are aware of the literature on NE, dopamine and food intake, which brings me to a question of some of your drug studies. The drugs were non-specific. Do you have any intention to measure the other catecholamines and so forth? DR. WEISS: Yes, we’ve begun to do that. That time course data was done to find out whether any of the monoamines were better related to the behavioral changes we might see. We haven’t begun to look at the behavioral changes. We have looked at severe stress effects and seen what it did to motor activity and tried to relate it to other monoamines but at only one time point. The answer to that whole question seems to be to give an absolutely precise definition of which neurotransmitters where are mediating the phenomenon. Once you can do that, you can specifically go in and look and see whether that particular change follows all of the functional predictions you would like to make. DR. WEIZJZNBAUM: You use the term ‘stressor’, which again, is an interesting term, particularly in light of Seymour Antelman’s work with the tail pinch. Do you think there is any relationship between the stressors that are applied and the ones that either or both of you use and Seymour Antelman’s technique? DR. WEISS: Yes, it’s probably all tied up in one very complex bundle in the sense that the treatments that we give affect monoamines and amount of intake. How to sort it all out so we know exactly what leads to what is a very difficult question and one which we’ve stayed away from here. I don’t think we’re going to gain very much by. . . DR. SELIGMAN:I think the tail pinch data are intriguing and important for helplessness. One of the things we’re going to be doing is seeing, for the parameters both Jay and I are using, if you get higher thresholds for pain and for lifting your foot and licking it on a hot plate. If you do get higher thresholds in non-instrumental situations, that’s disconfirming of the helplessness hypothesis and the learned inactivity one, for that matter. Because it says you’ve got pain threshold changes and that’s certainly not predicted! That in itself seems to me to be a viable hypothesis that could explain some of the data lying around. DR. WEKS: I’ll make the prediction right now; that experiment will work. You’ll find changes in pain threshold. DR. SELIGMAN:And then what would you then say theoretically about either learned inactivity or learned helplessness? DR. WEISS: We’re both in trouble. Laughter. WILLIAM B. PAVLIK, VP1 AND SU: To me, about the most amazing set of data I’ve looked at this afternoon was Dr. Weiss’ shock duration data. Especially that difference between a 4 s shock and a 5 s shock. I wonder about the description of a series of constant length shocks, whether they be 2 s or 6 s, as inescapable shocks. Now certainly, in terms of the programming equipment and the experimenter’s intentions, they
512
MAKTINE.P.
SELIGMANand JAY M. WEISS
are inescapable. But what we know in other situations about fixed temporal events. whether it be a Skinnerian FI schedule or even Pavlovian Temporal conditioning, suggests that there is a certain strengthening of certain collateral behaviors by adventitious reinforcement. You end up with very strong superstitious patterns of responding in animals when there is a fixed time course separating reinforcing events. I can’t help but wonder whether or not that particular experimental strategy (to give a constant fixed time shocks) might not, in fact, be producing (as in fact, I think you are suggesting with the longer shocks) stereotyped patterns of behavior which could either interfere with or facilitate subsequent responding in a different task. DR. WEIRS:That’s what I thought Marty was going to say to the brief shock, but I think someone should say even if it wasn’t brought up in that context. With a very brief shock it may be that the animal is doing things and he doesn’t perceive the uncontrollability of it. Of course, I tend not to like to use those kinds of formulations. But it’s certainly a possibility that one must consider. Offhand, I don’t know how one could get around it. DR. SELIGMAN: I think I have two relevant observations, Bill, that I think disconfirm the possibility. Actually, historically that was the very first hypothesis that Overmier and I had. And to test that hypothesis we compared a group of dogs that got 64 5 s shocks with 640 0.5 s shocks. The logic of using a 0.5 s shock was that, if you wanted to maximize shock going on and then some response occurring and it being paired adventitiously with shock termination, that a 0.5 s should really give it to you. In those two groups, six out of eight animals in both groups were helpless. So that didn’t make the difference. Even more significantly is that throughout this literature there are yoked controls. Now the yoked controls, in fact, don’t give you fixed length shock, they give you, generally, decreasing duration. Generally, it seems to be the case in both the rat and dog literature that about two out of three of the animals are helpless. So I’m inclined to believe that there isn’t superstitious learning going on here based on constant duration. After several further questions from the audience, the session was adjourned.
hhRTIN E. P. SEUGMAN and JAY M. WEISS
PART
VII:
QUESTIONS
FROM
THE
AUDIENCE
F. KEHOE,VP1 AND SU: I’d like to address this to both of you. You may decide for yourselves who will respond. If learning did take place in the nose-poke task, what would the learning curve look like and how could you empirically distinguish learning from accidental responding? DR. WEISS: Maybe the best thing is for me to respond to that ui.+&uis the two experiments that Marty suggested. We’ve looked at it by using the learning curve as a criterion that some kind of learning has taken place; I’m certainly not above considering that there are a whole host of other ways of determining ‘whether learning is occurring in that experiment. Nevertheless, the learning curve suggests that the animals are, in fact, learning something. I think the second experiment that Marty suggested, in which he delivers noncontingent shocks is more interesting than the first he suggested, assuming that he measures responses over a sufficient number of trials. In the beginning, pre-shocked animals might be better than non-shocked animals because they might simply move forward, but this initial effect should wear off. Over the long term, performance of the nosing task by the pre-shocked animals should not be much different from that of the non-shocked animals. The first experiment Marty suggested, in which he is going to deliver 10 noncontingent shocks prior to training, and then look at what appears afterward, is particularly weak. I think the problem with that is that you’re now giving the animals an uncontrollable shock treatment and you may have effects of that per se which mask the things you want to look at later. So I’d be much more impressed by seeing the results of the second experiment than those of the first. Let me talk for just a second about replicability of the phenomenon. You see, this is the sort of thing that gets me about the learned helplessness argument. Marty often replies to our results by saying, “First, they won’t replicate, but, if they do replicate, we can explain them.” When does the ‘helplessness’ hypothesis become faisifiable? When does one set up an experiment and, based on the results of the study, say the hypothesis does not work? I would say that the duration data has to replicate. If the duration data doesn’t replicate, I’ll withdraw my criticisms of the learned helplessness argument with respect to their rat experiments. The duration data must replicate, in my estimation, and it definitely will.* With respect to the nosing experiment, you have to be very careful with that study. We worked for a long time to get just the right apparatus. The reason we didn’t do some of the crucial studies that you asked about, Marty, is that we, like you, spent 4 or 5 years looking for learned helplessness in the rat. It’s very easy not to replicate somebody else’s experiment by just grabbing a tube and trying it. I’ll tell you right now the animal’s got to be the right size. You’ve really got to work. I’ll be glad to tell the person involved how to replicate the phenomenon. Laughter. DR. SELIGMAN:Let me comment as well. I agree with Jay that the second experiment is a better experiment than the first experiment. There is a third experiment which I think should be done, which I think is a rather crucial experiment. It’s just rather difficult to do. Assuming the reality of the effect, and, assuming that Jay can tell us exactly how to get this effect, the question then becomes: what happens if you hold the motor response easy (in this case, falling into the ‘hole) and again, like the FR-1 with a delay, degrade the contingency without changing motor requirements? If learning is going on and you now make the animal try to learn this with, say, a 3 s delay of shock termination, the helplessness hypothesis predicts that now you should see the performance of these animals deteriorate (the ones who got inescapable shock) because although they’ve got the motor incapacity to do it (if you will, they’ve got the inactivity),
JERARD
* This result has been replicated since this discussion. The reference is: Anisman H., de Catanzaro D. and Remington G. (1978) Escape performance following exposure to inescapable shock. Deficits in motor response maintenance. J. exp. Psychol. Animal Behav. Processes 4, 197-218.
Learned helplessness, physiological change and learned inactivity
511
they’re going to have trouble seeing the connection between falling in the hole and shock going off 3 s later. That would be one way of testing it. But I must take exception to Jay’s point about the logic of “Well, it doesn’t replicate; but, even if it did replicate, we can still explain it. Therefore, the hypothesis is unfalsifiable.” That just doesn’t go through at all. There are all sorts of experiments which don’t differentiate between helplessness and inactivity. Jay has done some of them. Whether or not they are replicable doesn’t apply to that. The falsifiability question is whether or not there are any experiments at all which, if they turned out in a given direction, would make us give up the learned helplessness hypothesis. I listed five of those for you. DR. WEISS: But all of those experiments have already been done. DR. SELIGMAN:The question is, in principle, falsifiable, though. That’s the logic of the philosophy of science as I understand it. DR. WEISS: Yes, that is true. DR. SELIGMAN:I think the evidence is already in, basically. FREYAWEIZENBAUM,VP1 AND SU: Jay, I know you are aware of the literature on NE, dopamine and food intake, which brings me to a question of some of your drug studies. The drugs were non-specific. Do you have any intention to measure the other catecholamines and so forth? DR. WEISS: Yes, we’ve begun to do that. That time course data was done to find out whether any of the monoamines were better related to the behavioral changes we might see. We haven’t begun to look at the behavioral changes. We have looked at severe stress effects and seen what it did to motor activity and tried to relate it to other monoamines but at only one time point. The answer to that whole question seems to be to give an absolutely precise definition of which neurotransmitters where are mediating the phenomenon. Once you can do that, you can specifically go in and look and see whether that particular change follows all of the functional predictions you would like to make. DR. WEIZJZNBAUM: You use the term ‘stressor’, which again, is an interesting term, particularly in light of Seymour Antelman’s work with the tail pinch. Do you think there is any relationship between the stressors that are applied and the ones that either or both of you use and Seymour Antelman’s technique? DR. WEISS: Yes, it’s probably all tied up in one very complex bundle in the sense that the treatments that we give affect monoamines and amount of intake. How to sort it all out so we know exactly what leads to what is a very difficult question and one which we’ve stayed away from here. I don’t think we’re going to gain very much by. . . DR. SELIGMAN:I think the tail pinch data are intriguing and important for helplessness. One of the things we’re going to be doing is seeing, for the parameters both Jay and I are using, if you get higher thresholds for pain and for lifting your foot and licking it on a hot plate. If you do get higher thresholds in non-instrumental situations, that’s disconfirming of the helplessness hypothesis and the learned inactivity one, for that matter. Because it says you’ve got pain threshold changes and that’s certainly not predicted! That in itself seems to me to be a viable hypothesis that could explain some of the data lying around. DR. WEKS: I’ll make the prediction right now; that experiment will work. You’ll find changes in pain threshold. DR. SELIGMAN:And then what would you then say theoretically about either learned inactivity or learned helplessness? DR. WEISS: We’re both in trouble. Laughter. WILLIAM B. PAVLIK, VP1 AND SU: To me, about the most amazing set of data I’ve looked at this afternoon was Dr. Weiss’ shock duration data. Especially that difference between a 4 s shock and a 5 s shock. I wonder about the description of a series of constant length shocks, whether they be 2 s or 6 s, as inescapable shocks. Now certainly, in terms of the programming equipment and the experimenter’s intentions, they
512
MAKTINE.P.
SELIGMANand JAY M. WEISS
are inescapable. But what we know in other situations about fixed temporal events. whether it be a Skinnerian FI schedule or even Pavlovian Temporal conditioning, suggests that there is a certain strengthening of certain collateral behaviors by adventitious reinforcement. You end up with very strong superstitious patterns of responding in animals when there is a fixed time course separating reinforcing events. I can’t help but wonder whether or not that particular experimental strategy (to give a constant fixed time shocks) might not, in fact, be producing (as in fact, I think you are suggesting with the longer shocks) stereotyped patterns of behavior which could either interfere with or facilitate subsequent responding in a different task. DR. WEIRS:That’s what I thought Marty was going to say to the brief shock, but I think someone should say even if it wasn’t brought up in that context. With a very brief shock it may be that the animal is doing things and he doesn’t perceive the uncontrollability of it. Of course, I tend not to like to use those kinds of formulations. But it’s certainly a possibility that one must consider. Offhand, I don’t know how one could get around it. DR. SELIGMAN: I think I have two relevant observations, Bill, that I think disconfirm the possibility. Actually, historically that was the very first hypothesis that Overmier and I had. And to test that hypothesis we compared a group of dogs that got 64 5 s shocks with 640 0.5 s shocks. The logic of using a 0.5 s shock was that, if you wanted to maximize shock going on and then some response occurring and it being paired adventitiously with shock termination, that a 0.5 s should really give it to you. In those two groups, six out of eight animals in both groups were helpless. So that didn’t make the difference. Even more significantly is that throughout this literature there are yoked controls. Now the yoked controls, in fact, don’t give you fixed length shock, they give you, generally, decreasing duration. Generally, it seems to be the case in both the rat and dog literature that about two out of three of the animals are helpless. So I’m inclined to believe that there isn’t superstitious learning going on here based on constant duration. After several further questions from the audience, the session was adjourned.