Minds of small things · Article

Associative memory as the condition of consciousness

Jacques Loeb held that consciousness is the function of a definite mechanism, the one that underlies associative memory¹. He argued that automatic self-preserving processes occur in every organism, but the apparatus for associative memory occurs in only some, and without it consciousness is impossible⁴. This gave a test that could be applied across the animal kingdom, though other authors disputed it⁶.

Earliest held: 1859, Darwin
Most discussed in: The Principles of Psychology, Vols. 1-2, 1890
In the library: 1,134 passages in 69 works
Rewritten: 2026-11-07

Loeb's criterion

Loeb stated the view in his 1906 lectures. He called consciousness the function of a definite machine, the mechanism of associative memory¹. In Comparative Physiology of the Brain (1900), restated in The Mechanistic Conception of Life (1912), he used the criterion to reject the idea that all matter, and so the whole animal world, has consciousness². In his account only certain species have associative memory, and it appears in them only after a certain stage of development². He also addressed a common objection. Respiration is automatic, yet people can become conscious of it. Loeb said this does not show that the process is conscious in every organism that has it⁴.

Evidence from brain operations

Loeb cited the results of brain operations as support for the view. He reported that removing the cerebral hemispheres causes complete loss of associative memory in higher animals³. He added that vertebrates with little or no associative memory, such as the shark or frog, differ little in their reactions after losing the hemispheres². In 1918 he applied the criterion across groups. He credited certain vertebrates, insects, crustaceans and cephalopods with associative memory. For worms, starfish, sea urchins, actinians, medusae, hydroids and infusorians he knew of no adequate proof⁷.

Disputes over the test

Jennings described associative memory in objective terms, as a response to one stimulus that comes to be transferred to another⁵. Washburn, in her 1908 textbook, questioned what learning can show about consciousness. She asked whether a single strong experience might change behaviour without being revived as an idea⁶. She also noted that dogs and cats solve some problems too slowly for ideas to be inferred, so slow learning does not settle the question⁶.

Later work

Blackiston and colleagues (2008) tested associative memory in the hornworm Manduca sexta. They concluded that larvae learned to link an odour with an aversive stimulus, and that the memory survived metamorphosis into adulthood⁸. Levin (2022) took a graded view in his TAME framework. He suggested that consciousness comes in degrees and kinds and is not binary⁹. This is a different position from Loeb's claim that only certain animals have it².

SourcesEach quotation was checked word for word against the passage it opens.

We are brought to the theory that only certain species of animals possess associative memory and have consciousness, and that it appears in them only after they have reached a certain stage in their ontogenetic development.Loeb, J., 1900 · Comparative Physiology of the Brain and Comparative Psychology · open at passage 23
Extir- pation of the cerebral hemispheres causes complete loss of associative memory.Loeb, J., 1900 · Comparative Physiology of the Brain and Comparative Psychology · open at passage 354
I will simply state here that I consider conscious- ness the function of a definite machine or mechanism, which we may call the mechanism of associative memory.Loeb, J., 1906 · The Dynamics of Living Matter · open at passage 20
These authors overlook the fact that the automatic mech- anisms of self-preservation must occur in every organism, while an apparatus for associative memory may be found only in a limited num- ber of organisms.Loeb, J., 1906 · The Dynamics of Living Matter · open at passage 21
This is characterized objectively by the fact that the response at first given to one stimulus comes, after a time, to be transferred to another one.Jennings, H. S., 1906 · Behavior of the Lower Organisms · open at passage 938
Where the motive, the beneficial or harmful consequence of action, is very strong, may not a single experience suffice to modify action without being revived in idea?Washburn, M. F., 1908 · The Animal Mind: A Textbook of Comparative Psychology · open at passage 68
while to the knowledge of the writer no adequate proof for its existence has ever been given for worms, starfish, sea urchins, actinians, medusae, hydroids, or infusorians.Loeb, J., 1918 · Forced Movements, Tropisms, and Animal Conduct · open at passage 293
The behavior represents true associative learning, not chemical legacy, and, as far as we know, provides the first definitive demonstration that associative memory survives metamorphosis in Lepidoptera.Blackiston DJ, Silva Casey E, Weiss MR, 2008 · Retention of memory through metamorphosis: can a moth remember what it learned… · open at passage 13
Provisionally, I suggest that consciousness also comes in degrees and kinds (is not binary)Levin M, 2022 · Technological Approach to Mind Everywhere: An Experimentally-Grounded Framework… · open at passage 104

Linked ideas

Criteria of mindpart of / contains

Loeb's associative-memory test is one of several proposed criteria for deciding which organisms have mind.

Conditioned reflexrelated to

Pavlovian conditioning is the standard laboratory form of the stimulus transfer that Jennings and Loeb called associative memory.

Memory retention through metamorphosisrelated to

Blackiston and colleagues showed that associative memory in Manduca survives metamorphosis.

Gene regulatory network models of associative learning and bistable memoryparallels

Associative memory is modelled in regulatory networks, where Loeb tied it to a brain mechanism.

Basal cognitionin tension with

Basal cognition looks for memory and cognition in simple or non-neural systems, where Loeb saw no adequate proof.

Memory as adaptationrelated to

Memory is treated there as adaptation; Jennings grounded associative memory in the same law as ordinary memory.

Auto- and heteroassociative memory in gene regulatory networksin tension with

Biswas et al. model associative memory in transcriptional networks and De la Fuente et al. report it in amoebae, which challenges B's premise that only some animals have the mechanism. No passage mentions Loeb.

The plasma membrane as cellular nanobrain (senome)in tension with

Both tie consciousness to memory, but Baluška et al. make it universal to all living cells and organisms, while Loeb restricts it to animals with an associative-memory mechanism.

Binding problem and integration of information in consciousnessrelated to

Levin's passage says associative memory linking experiences of different cells belongs to an emergent collective, a binding-like integration. No passage mentions Loeb or ties memory to consciousness; IIT passages cover integration only.

Where it is discussedPassages matching associative memory, apparatus for associative memory, automatic mechanisms of self-preservation, consciousness

1890	The Principles of Psychology, Vols. 1-2 · James, W.	544
1908	The Animal Mind: A Textbook of Comparative Psychology · Washburn, M. F.	65
1925	Elements of Physical Biology · Lotka, A. J.	62
1900	Comparative Physiology of the Brain and Comparative Psychology · Loeb, J.	60
1908	The Science and Philosophy of the Organism · Driesch, H.	38
2020	Integrating information in the brain's EM field: the cemi field theory of… · McFadden J	35
2020	Sentience and the Origins of Consciousness: From Cartesian Duality to Markovian… · Friston KJ, Wiese W, Hobson JA	26
1903	The Nature of Man: Studies in Optimistic Philosophy · Metchnikoff, E.	21
1906	The Integrative Action of the Nervous System · Sherrington, C. S.	18
2022	Technological Approach to Mind Everywhere: An Experimentally-Grounded Framework… · Levin M	18