Physiological Psychology 1980, Vol. 8 (2), 149-151

A. H. Black 1929-1978

In this respect the pursuit of science seems to me to require particular courage. It is concerned with knowledge, achieved through doubt. Making knowledge about everything available for everybody, science strives to make sceptics of them all.

Abe would have liked this conference. In both style and content, it was a fitting memorial to him. Diverse theoretical perspectives were represented, several papers reported the type of analytical experiment for which Abe was famous, and the discussions were tough, honest, and cordial.

Abe came to the hippocampus from a background in animal learning theory and spent much of his last years trying to reconcile the stimulus-response ap­proach to learning and behavior with the more recent cognitive theories of hippocampal function. I think he himself had become convinced of the need for cognitive models but remained true to the analytic rigor and methodological traditions of the behaviorist. Whether or not he was correct, only time will tell. It is clear, however, that hippocampal studies have benefited from his courageous compromise. It took courage to present the case for cognitive ideas to behaviorist-oriented audiences; it took fortitude to insist that cognitive theories match the S-R theories in precision and predictive power. The ease with which the members of this conference have com­municated despite their diverse theoretical allegiances owes more than a little, I think, to the mediation of Abe Black and stands as a clear refutation of Kuhn's thesis that different theoretical paradigms are doomed to perpetual isolation. Abe helped to build the bridge on which this conference stands. As one who was dragged somewhat reluctantly back and forth across that bridge, I am extremely grateful.

Let me say a bit about how I think Abe came to play this important role. His scientific career had several distinct phases and might be viewed as a steady movement from the peripheral receptor/effector interests of the behaviorist to the central nervous system focus of the cognitive neuroscientist.

Abe obtained his PhD in Solomon's lab at Harvard in the mid-50s during the height of interest in two­factor theory of avoidance conditioning. One prob­lem with this theory had been uncovered by Solomon and his students (e.g., Solomon, Kamin, & Wynne, 1953), who found that animals did not easily ex­tinguish responding in the Miller-Mowrer two-way

Copyright 1980 Psychonornic Society, Inc. 149

From The Life of Galileo by Bertolt Brecht (passage marked in Abe's own copy)

avoidance task unless the response was blocked. In order to show that this was not due to the develop­ment of an alternative response which conflicted with the avoidance response, Abe extinguished the ani­mals while they were paralyzed with a curare-like drug so that no response was possible. These animals still extinguished faster than controls, apparently ruling out the response conflict hypothesis. I say "apparently" because one of the ideas that was eventually to drive Abe into the CNS was his realiza­tion that blocking an overt motor response did not prevent conditioning of the central movement pro­cesses that generate that response. Throughout his career, Abe was to use the technique of paralysis as a powerful analytic tool for the study of conditioning.

After his doctoral work, Abe returned home to Canada to take a position in the psychology depart­ment of McMaster University. He remained there for the rest of his life, becoming full professor in 1966. His interest in avoidance learning continued, and he began to search for an index of fear and anxiety that was independent of the avoidance re­sponse being conditioned.

He used two approaches to this problem. One was to monitor heart rate during avoidance learning and extinction and the other, undertaken with his close friend, Leo Kamin, was to use a transfer experiment in which the fear elicited by a CS in one situation could be measured behaviorally in an independent situation. This latter experiment (Kamin, Brimer, & Black, 1963) showed that the amount of avoidance to a CS in a shuttlebox was not perfectly correlated with the amount .. of fear elicited by the same CS in a conditioned suppression leverpress task. This contra­dicted the assumption of two-factor theory that con­tinued fear of the CS was necessary for the mainte­nance of a well-learned avoidance response.

The use of heart-rate changes as a monitor of fear was less successful, since these seemed to correlate better with general motor activity than with fear (Black, 1959). Abe continued to study heart-rate conditioning as an interesting phenomenon in itself but, after exhaustive study, was compelled to con-

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150 O'KEEFE

clude that conditioned changes in heart rate were not primary phenomena but were actually secondary concomitants of conditioned changes in central move­ment circuits. One of the crucial findings was that animals that were operantly conditioned to increase heart rate to a CS while they were paralyzed and therefore incapable of moving nevertheless moved in response to the CS when subsequently tested in the unparalyzed state (Black, 1971). The dogs were being trained to "attempt to move" in spite of the fact that they couldn't do so. This series of results caused considerable difficulties for those theories of avoid­ance learning which posited that the motivational stimuli that support avoidance responses arise from classically conditioned fear responses to the CS. The conclusion that conditioned autonomic changes were concomitants of changes in some central movement state also brought Abe into conflict with Di Cara and Miller, who at that time were reporting that auto­nomic variables such as heart rate could be operantly conditioned independently of skeletal movement (e.g., Di Cara & Miller, 1969). I know it brought Abe little satisfaction that subsequent events tended to support his position (Black, 1974), and he was particularly distressed by the death of Di Cara during that period. More than once he told me of his inten­tion to write an informal history of this whole story, since he saw it as an important chapter in psychology and particularly one that raised fundamental issues in the sociology of science and the politics of science. Despite his reservations about some of the theoretical claims made about the operant conditioning of auto­nomic processes, he always remained convinced of the practical and therapeutic value of these tech­niques (Black & Cott, 1977).

His conclusion that many forms of autonomic and skeletal conditioning were reflections of the conditioning of central movement states led Abe into the central nervous system to search for those states. Case Vanderwolf, who was at the time in the same department at McMaster, had claimed that a close correlation existed between theta activity in the hippocampal EEG and voluntary movements (Vanderwolf, 1969, 1971) and suggested that theta might reflect a central movement state. Abe seized upon this opportunity to test the idea that central movement states could be directly conditioned, and he repeated several of his conditioning experiments using the hippocampal EEG waves in place of the heart rate. The results were a series of classic ex­periments demonstrating the intimate relationship between high-frequency hippocampal theta and movement in the dog. In one set of experiments, dogs conditioned to press a lever to avoid shock showed more theta during the CS than dogs con­ditioned to hold still to avoid shock (Black & Young,

1972; Dalton & Black, 1968). In a second set, dogs conditioned to produce theta showed more move­ment than those conditioned to refrain from making theta. This held even when the conditioning took place while the dogs were paralyzed and subsequently tested in the unparalyzed state (Black, 1972). As Abe pointed out, feedback from the skeletal movements is not important for the conditioning of the brain activity. These experiments indicated a bidirectional correlation between hippocampal theta activity and movements and provided strong support for Vanderwolf's hypothesis. In a third series of experi­ments, Abe tried to dissociate the two variables, this time in the rat. Two groups of animals were asked to generate high-frequency theta. One was allowed to move, but the other had to hold still. The second group could not generate high-frequency theta dur­ing immobility but did manage some low-frequency theta. The animals that were free to move had no trouble producing high-frequency theta (Black, 1975).

To my mind, this series of experiments stands as one of the finest examples of analytic attack on a simple hypothesis of brain and behavior correlations. They seem to leave little room for conclusion other than that there is a strong relationship between theta activity in the hippocampal EEG and movements. This work certainly convinced Lynn Nadel and my­self that any theory of hippocampal function must account for the fact that the hippocampus has access to information about some aspect of the animal's movements.

I first met Abe and his wife, Janet, at a conference in Vienna in 1971. We got along well from the start and it was soon decided that Abe would spend his 1973-1974 sabbatical year with Lynn and me in London. During that year, Abe and Janet fell in love with London and returned once or twice a year until Abe's death.

By 1972, Lynn and I had finished the first draft of our book, and Abe spent an enormous amount of time critically reviewing it both before and during the year in London. Abe was one of those people whom journal editors come to rely on heavily, the unsung heroes of science who give unstintingly of their time, reading, correcting, and improving the unpublished manuscripts of others. There is often a lot hidden in the simple "thank you" at the end of a paper. Until that year I had thought that Lynn was unique in his scholarly obsession with the literature. Now I was faced with two of them. My training at the hands of the Jesuits had left me sorely deficient when con­fronted with these two Talmudic scholars. Some of my fondest memories are of Abe and Lynn sitting side by side at a large window bench piled high with behavioral papers, tabulating, checking, rechecking, arguing, resolving. Two review papers resulted from

our discussions (Black, Nadel, & O'Keefe, 1977; Nadel, O'Keefe, & Black, 1975).

During this period, we formulated many tests of the cognitive map theory and ran several pilot studies. Abe and I followed up a report by Whishaw and Vanderwolf (1973) that the frequency of hippo­campal theta increased with jumps of increasing height. We were later joined in this work by Richard Morris, now at St. Andrews, and a preliminary re­port has appeared (Morris, Black, & O'Keefe, 1976).

Abe, Lynn, and I also ran several behavioral ex­periments, many of which have still not been turned into proper published experiments. One exception is a passive avoidance study which shows that fornix lesioned rats can avoid cues but not places, as pre­dicted by the 1977 review paper (Okaiche, Anchel, Barbaree, & Black, 1978).

I should not give the impression that all of Abe and Janet's time in London was totally occupied with the hippocampus. They both had many extra­scientific interests centered primarily on art and the theater. He was something of an art connoisseur and was particularly knowledgeable about, and attracted to, the German expressionists. Their bleak represen­tations of the human condition not only satisfied his artistic sensibility, but also accorded well with his own perception of reality. He had suffered much through the premature death of his first wife and was acutely aware of the suffering of others. This may come as a surprise to many of his academic col­leagues who knew Abe only as the tough professional, an image I think he secretly enjoyed. In a sense, his own premature death seems a bitter confirmation of his dark vision of the human condition.

That is not to say that Abe didn't enjoy a good laugh. On the contrary, he usually exuded a quiet joie de vivre and had a fine sense of humor. Some­what misled by his external public persona, Lynn and I were surprised at how easily he fell in with the sense of mischief and irreverence which pervaded our group and how much he enjoyed playing Groucho Marx to Lynn's Woody Allen. During our numerous "business" lunches, Abe proved disconcertingly agile at defending both his theoretical position and his chocolate cake against our well-organized attacks. On both battle fronts, his mock plaintive, "Ah, come on, you guys!" quickly gained the status of a truce signal.

Abe had many pleasures and displeasures. A few of his likes were: Brecht plays, the poems of Sylvia Plath, beating me at squash, walking to work, win­ning an argument, his role as a Jewish patriarch of the family and the lab, his cigar, the adventure of science, his cup of tea. He disliked being destroyed by Lynn (or anyone) at squash, a botched or dis­honest argument, his role as a Jewish patriach of the family and the lab, social injustice, an unfinished task.

A. H. BLACK 151

A superb analytical mind, a strong character, a builder of bridges, a good friend.

It's not the same without him. John 0 'Keefe

REFERENCES

BLACK, A. H. Heart-rate changes during avoidance learning in dogs. Canadian Journal of Psychology, 1959, 13, 229-242.

BLACK, A. H. Autonomic aversive conditioning in infrahuman subjects. In R. F. Brush (Ed.), Aversive conditioning and learn­ing. New York: Academic Press, 1971.

BLACK, A. H. The operant conditioning of central nervous sys­tem electrical activity. In G. H. Bower (Ed.), The psychology of learning and motivation (Vol. 6). New York: Academic Press, 1972. [Reprinted in: Biofeedback and self-control annual (1972 ed.). Chicago: Aldine Press, 1973.)

BLACK, A. H. Unlearning visceral learning. New Scientist, 1974, 61,269-270.

BLACK, A. H. Operant conditioning of CNS electrical activity and the neural basis of learning. In M. H. Chase & S. Fox (Eds.), Operant control of the electrical activity of the brain. Los Angeles: UCLA Brain Research Institute, 1975.

BLACK, A. H., & COTT, A. A perspective on biofeedback. In J. Beatty (Ed.), Biofeedback and behaviour: A NATO sympo­sium. New York: Plenum, 1977.

BLACK, A. H., NADEL, L., & O'KEEFE, J. Hippocampal function in avoidance learning and punishment. Psychological Bulletin, 1977,84,1107-1129.

BLACK, A. H., & YOUNG; G. A. The electrical activity of the hippocampus and cortex in dogs operantiy trained to move and to hold still. Journal of Comparative and Physiological Psychology, 1972,79, 128-141.

DALTON, A., & BLACK, A. H. Hippocampal electrical activity during the operant conditioning of movement and refraining from movement. Communications in Behavioural Biology, 1968,2,267-273.

DI CARA, L. V., & MILLER, N. E. Transfer of instrumentally learned heart-rate changes from curarized to non-curarized state: Implications for a mediational hypothesis. Journal of Comparative and Physiological Psychology, 1969, 68, 159-162.

KAMIN, L. J., BRIMER, C. J., & BLACK, A. H. Conditioned sup­pression as a monitor of fear of the CS in the course of avoid­ance training. Journal of Comparative and Physiological Psychology, 1963,56,497-501.

MORRIS, R. G. M., BLACK, A. H., & O'KEEFE, J. Hippocampal EEG during a ballistic movement. Neuroscience Letters, 1976, 3,102.

NADEL, L., O'KEEFE, J., & BLACK, A. H. Slam on the brakes: A critique of Altman, Brunner and Bayer's response inhibition model of hippocampal function. Behavioral Biology, 1975, 14, 151-162.

OKAICHE, H., ANCHEL, H., BARBAREE, H., & BLACK, A. H. The punishment of runway behavior in rats with fornical lesions. Physiology & Behavior, 1978,21,503-509.

SoLOMON, R. L., KAMIN, L. J., & WYNNE, L. C. Traumatic avoidance learning: The outcomes of several extinction pro­cedures with dogs. Journal of Abnormal and Social Psychology, 1953,48,291-302.

VANDERWOLF, C. H. Hippocampal electrical activi;ty and volun­tary movement in the rat. EEG Clinical Neurophysiology, 1%9, 26,407-418.

VANDERWOLF, C. H. Limbic-diencephalic mechanisms of volun­tary movement. Psychology Review, 1971,78,83-113.

WHISHAW, I. Q., & VANDERWOLF, C. H. Hippocampal EEG and behavior: Changes in amplitude and frequency of RSA (theta rhythm) associated with spontaneous and learned movement patterns in rats and cats. Behavioral Biology, 1973, 8, 461-484.