Orbach seeks to provide a retrospective view of the role of Lashley and Hebb in the development of neuropsychological theory and, in particular, the Hebb synapse. The book provides a unique resource for neurohistorians interested in the origin of ideas that have shaped neuropsychological thinking for the second half of the century. One theme throughout Orbach's notes is that Lashley did not receive the credit he deserved. Although Orbach's point is well taken, I was not entirely convinced, any more than I am that Darwin received more than his share of credit for his theory of evolution.
2. As I read the volume it seemed to me that Orbach had tried, consciously or not, to accomplish several things. First, there is the publication of the Vanuxem lectures. Second, there is a lesson in history. Third, there is the attempt to set straight priority in ideas. Finally, there is the relationship between Hebb and Lashley as well as the authors relationship with Hebb and Lashley. I consider each of these in turn.
3. The Vanuxem Lectures may not be the highlight of Lashley's publications, but they do provide some insight into what he thought about the issues that Hebb had addressed in his 1949 book. The mere publication of these lectures makes the publication of the current volume worthwhile. Furthermore, putting them in the context of the selected papers of Lashley makes this part of the volume useful as a starting point for a graduate seminar. What I found disappointing, however, was that he did not include selected papers of Hebb, particularly post-1949 papers. It strikes me that many current students know Hebb only for his book, but as Orbach knows, there was much more. This omission is all the stranger when we consider that the timing of the book was in honour of the fiftieth anniversary of the publication of Hebb's book. I got the impression throughout the book that Lashley was the "main man" and Hebb was the disciple who got all the credit.
4. The current volume serves to remind us where neuropsychology, and by extension cognitive neuroscience, comes from. The current focus on imaging studies and molecular neuroscience tends to shift, giving one the impression that most of what we know about the relationship between brain and behavior is a product of the "Decade of the Brain." Nothing could be further from the truth. There can be little doubt that the decade of the brain has stimulated the discovery of an enormous amount of information about such things as channels, genes, and blood flow during thinking but these are, in essence, merely details about how the mechanics of the brain might work. The fundamental ideas about brain-behavior relationships are not new, they come from more than fifty years ago in the writings of Lashley and Hebb, and others like Penfield and Hughlings Jackson.
5. One aspect of history that does not come through in Orbach's volume, and I think is extremely important, is the importance of Hebb in developing Canadian psychology. It may not be so apparent to non-Canadians, and to Americans in particular, but during the 1950s and 1960s Hebb trained the students who would become the leaders of behavioural neuroscience both in Canada and beyond. Names like Brenda and Peter Milner, Doreen Kimura, Roy Wise, Richard Tees, Case Vanderwolf, to name only a few, come to mind. And, of course, this group then had students that too were trained in the Hebb tradition. This group took with them a way of thinking about brain-behavior relationships that has led to a Canadian contribution to brain, behaviour, and cognitive science that is proportionally far greater than would be expected from the small population of Canada. Hebb's influence in training at least two generations of students clearly distinguishes him from Lashley who did not have the same impact on developing students.
6. One of the historical points that Orbach spends some time on is the importance of "Lashley's lesson." With this, Orbach is referring to Lashley's idea that the effects of learning will be seen at synapses that were not excited during original learning. I was certainly aware of Lashley's idea but I found Orbach's revisiting of this notion troubling for a couple of reasons. First, although Lashley had a good point, I can see absolutely no evidence favoring this view, other than Lashley's claim that no specific memory has ever been deleted by a cerebral injury. I am not sure that is so, at least when memory is considered in the broader context. Agnosias would seem to me to be precisely that. Indeed, many agnosics cannot even imagine what the lost knowledge would be like. Oliver Sacks's (1985) colour blind painter is an interesting case in point. He cannot imagine colour any more. This strikes me as a specific lost memory. I will concede that episodic memories do not seem to be lost after specific cerebral injuries but I wonder if that has more to do with the fact that the memories are far less specific than might appear. Second, as a person who has searched for morphological correlates of specific habit learning, I have been struck by the specificity of the morphological changes associated with learning (Kolb 1995). Animals trained to make specific movements, such as skilled reaching with the forelimbs, show stunningly specific changes in neuronal morphology, at least as revealed by Golgi techniques. I do not wish to belabor the point but it strikes this reader that a more thorough discussion of "Lashley's lesson" is in order and I would encourage Orbach to initiate such a debate in the future. The point is central to the nature of brain- behaviour relationships and, as Orbach asserts, should not be ignored. I certainly think that the majority of today's neuroscientists would not be familiar with the issue and they ought to be.
7. I must confess that I had not realized that Alexander Bain had anticipated Hebb by 75 years. I found the discussions of Lashley's ideas and the subtle implication that Hebb had somehow been credited for ideas that were not really his rather interesting. It struck me much like the debate as to whether Darwin received more than his share of credit for the theory of evolution. Like Darwin, Hebb was a gifted writer and clearly the telling of the story can be as important as the story. But should this be seen as a reason why Hebb was somehow given too much credit any more than Darwin has been? Perhaps the lesson here is that no ideas suddenly appear but reflect the slow development of thought. It also strikes this reader that Lashley's "error" was in being so negative about theory, rather than being more theoretical himself. As a result, with the exception of papers such as "The problem of serial order in behavior" (Lashley, 1951), Lashley seemed to be more intent on destroying than building.
Hebb, D.O. (1949) The Organization of Behaviour. New York: Wiley.
Kolb, B. (1995) Brain plasticity and behavior. Mahwah, NJ: Lawrence Erlbaum.
Lashley, K.S. (1951) The problem of serial order in behavior. In Jeffress, L.A. (Ed.) Cerebral mechanisms in behavior, pp. 112-136. New York: Wiley.
Lashley, K. S. (1929) Brain mechanisms and intelligence: A quantitative study of injuries to the brain. New York: Dover.
Orbach, J. (1982) Neuropsychology after Lashley. Hillsdale, NJ: Lawrence Erlbaum.
Orbach, J. (1998) (Ed.) The Neuropsychological Theories of Lashley and Hebb. University Press of America
Orbach, J. (1999) Precis of: The Neuropsychological Theories of Lashley and Hebb. PSYCOLOQUY 10(029). ftp://ftp.princeton.edu/pub/harnad/Psycoloquy/1999.volume.10/ psyc.99.10.029.lashley-hebb.1.orbach http://www.cogsci.soton.ac.uk/psyc-bin/newpsy?10.029
Sacks, O. W. (1985) The man who mistook his wife for a hat. London: Duckworth.