Jack Orbach (1999) Hebb's Cell Assemblies; Lashley's Reverberatory Circuits. Psycoloquy: 10(056) Lashley Hebb (5)

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PSYCOLOQUY (ISSN 1055-0143) is sponsored by the American Psychological Association (APA).
Psycoloquy 10(056): Hebb's Cell Assemblies; Lashley's Reverberatory Circuits

Reply to Milner on Orbach Lashley-Hebb

Jack Orbach
Department of Psychology
Queens College
Flushing, NY, 11367



What is the valid assignment of priorities to Lashley and Hebb for proposing neuropsychological mechanisms to sustain neural activity in the cerebral cortex?


cell assembly, central autonomous process, engram, equipotentiality, Hebb, Hebbian learning, Lashley, localization, memory trace, nativism, reverberatory circuit, Vanuxem Lectures
1. In his review of my Lashley-Hebb book (Orbach 1998, 1999), Milner (1999) takes me to task for suggesting that Lashley deserves credit for the conception of the cell assembly. But I never expressed that view. On page 71 of the book, I wrote:

    "Probably the most enduring idea embodied in the 1949 monograph,
    and for which the monograph is justly famous, is the empirically
    assembled nerve net that Hebb dubbed the 'cell assembly.' I would
    venture the opinion that the conception that functional nerve nets
    can be assembled by experience is one of the more important ideas
    in neuropsychological theory of the twentieth century.  Lashley
    never developed that idea, nor did he ever acknowledge it in print.
    We have to credit the 1949 monograph for its dissemination."

2. However, I do believe that Lashley deserves the credit for recognizing early in his career the importance of the non-sensory control of behavior, for introducing Lorente de No's reverberatory circuit to the neuropsychological community, and for suggesting that it might sustain activity in the cerebral cortex. The acquired neural lattice or cell assembly, as Hebb chose to call it in 1949, is quite another matter. Nevertheless, Hebb himself implied Lashley's contribution by offering him co-authorship in 1946. Why else would Hebb do that? He said publicly that he did it because he would be more likely to get a reading with Lashley's name on the title page, but the offer was gratuitous. The book was already written!

3. As far as we know, Lashley read just one draft of Hebb's book (not more). Hebb gave the manuscript to Lashley late in 1946 (not 1945 as suggested by Milner) and he returned it with critical comments in February, 1947. My review of his comments leads me to conclude that Lashley read no more than the first 96 pages of the draft (of over 300 pages) and Hebb published that draft more or less word for word in 1949. No changes were made as a result of Lashley's critique, though I believe that Hebb should have felt obliged to adopt Lashley's corrections in characterizing Lashley's own theory. Why should Hebb ask Lashley to review his manuscript when he had no intention to respond to any part of his critique? I believe it was to check whether Lashley would claim any part of the theory as his own.

4. Milner wrote, "He (Orbach) also shows us the less admirable side of Lashley, his stubbornness, lack of experimental rigor and, by implication, a tendency toward self-deception." Lashley certainly had a less admirable side, and some of this I highlight in my book. But stubbornness and lack of experimental rigor? Milner must have found evidence of this in Lashley's own writing, for I said nothing about these matters in my review of Lashley's experimental work. I have no evidence that Lashley was unusually stubborn, certainly no more than you or me. Furthermore I believe that his scientific rigor was truly admirable for the era during which he worked, the 1920's, '30's, and '40's. After all, he was the first to insist on anatomical verification of experimental brain lesions; he was the first to show that rats have pattern vision by devising the jumping stand. In my earlier book on Lashley (1982, pp. 2, 3), I reviewed the evidence on Lashley's scientific rigor, "Lashley insisted on the following: strict criteria of learning; multiple measures of learning (time, trials and errors to meet the criterion of learning); reliability of measurements; distinction of postoperative retention and postoperative initial learning; standard postoperative recovery period (10 days);" etc. It is true that Lashley was a sloppy surgeon. Knowing that about himself, I believe he enlisted Karl Pribram to do his chimpanzee brain ablations for him.


Hebb, D. O. (1949) The Organization of Behavior. NY: Wiley.

Milner, P. M. (1999) Cell Assemblies? Whose Idea? Book review of Orbach on Lashley-Hebb. PSYCOLOQUY 10(53). ftp://ftp.princeton.edu/pub/harnad/Psycoloquy/1999.volume.10/ psyc.99.10.053.lashley-hebb.4.milner http://www.cogsci.soton.ac.uk/cgi/psyc/newpsy?10.053

Orbach, Jack, (1982) Neuropsychology After Lashley. NJ: Erlbaum Associates.

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(23). ftp://ftp.princeton.edu/pub/harnad/Psycoloquy/1999.volume.10/ psyc.99.10.029.lashley-hebb.1.orbach http://www.cogsci.soton.ac.uk/cgi/psyc/newpsy?10.029

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