Breuer on "Intracerebral Tonic Excitation"

The following is a brief summary of Breuer's discussion of "Intracerebral Tonic Excitation", from the second section of Freud and Breuer's "Studies on Hysteria" (1895). PDF of Breuer's original text.

Breuer starts by contrasting the “two extreme conditions of the central nervous system: a clear waking state and dreamless sleep.” He asks, what is “the essential difference between the two conditions?”

He notes that, when fully awake, “every act of will initiates the corresponding movement; sense-impressions become conscious perceptions; and ideas are associated with the whole store present in potential consciousness. In that condition the brain functions as a unit with complete internal connections.” On the other hand, in the deepest sleep, the “severence of connections between the psychical elements is… total.”

He attempts to make sense of this through what he calls “tonic excitation”, which is the “conductive capacity” existing between psychical elements at any time. “Let us imagine a widely-ramified electrical system for lighting and the transmission of motor power; what is expected of this system is that simple establishment of a contact shall be able to set any lamp or machine in operation. To make this possible, so that everything shall be ready to work, there must be a certain tension present throughout the entire network of lines of conduction, and the dynamo engine must expend a given quantity of energy for this purpose. In just the same way there is a certain amount of excitation present in the conductive paths of the brain when it is at rest but awake and prepared to work.” (Note how he has to “imagine” such an electrical system, which we now take so thoroughly for granted that we might forget it exists.)

Breuer senses your confusion: what are these “psychical elements” and how do they work within the brain? He responds, with the entire foundation of neuropsychology: “We usually think of the sensory nerve cells as being passive receptive organs. This is a mistake. For the mere existence of a system of associative fibres proves that these sensory nerve-cells also send out excitation into the nerve-fibres. If excitation from two sensory cells flows into a nerve-fibre that connects them - whether per continuitatem or per contiguitatem - then a state of tension must exist in it. This state of tension has the same relation to the excitation flowing away in, for instance, a peripheral motor fibre as hydrostatic pressure has to the living force of flowing water or as electric tension has to an electric current. If all the nerve-cells are in a state of mean excitation and are exciting their nerve-processes, the whole immense network forms a single reservoir of ‘nervous tension’. Apart then from a potential energy which lies quiescent in the chemical substance of the cell and an unknown form of kinetic energy which is discharged when the fibres are in a state of excitation, we must assume the existence of yet another quiescent state of nervous excitation: tonic excitation or nervous tension.”

He discusses sleeping and waking, “tension” as an urge for activity or movement, lack of sensory stimuli felt as torture, boredom, producing an unpleasurable “excitement”: “such feelings are always generated when one of the organism’s needs fails to find satisfaction. Since these feelings disappear when the surplus quantity of energy which has been liberated is employed functionally, we may conclude that the removal of such surplus excitation is a need of the organism. And here for the first time we meet the fact that there exists in the organism a ‘tendency to keep intracerebral excitation constant’ (Freud).”

Breuer follows with a discussion of certain endogenous sources of excitation, the need for oxygen, food, water. He then tentatively reaches the topic that Freud would turn into a phenomenon: sex. He writes: “A transition between these endogenous increases of excitation [oxygen, food, water] and the psychical affects in the narrower sense is provided by sexual excitation and sexual affect. Sexuality at puberty appears in the first of these forms, as a vague, indeterminate, purposeless heightening of excitation. As development proceeds, this endogenous heightening of excitation, determined by the functioning of the sex-glands, becomes firmly linked (in the normal course of things) with the perception or idea of the other sex - and, indeed, with the idea of a particular individual, where the remarkable phenomenon of falling in love occurs. This idea takes over the whole quantity of excitation liberated by the sexual instinct. It becomes an ‘affective idea’; that is to say, when it is actively present in consciousness it sets going the increase of excitation which in point of fact originated from another source, namely the sex-glands.”

He continues discussing sexual instincts as a source of excitation. He describes how “when [excitation reaches] a considerable degree of intensity the train of ideas becomes disturbed and the relative value of the ideas is changed… perception too — the psychical interpretation of sense-impressions — is impaired.” He further claims that “A disturbance like this of the dynamic equilibrium of the nervous system — a non-uniform distribution of increased excitation — is what makes up the psychical side of affects.”

He continues his discussion, attempting to restrict himself to “a single point, which is of importance for pathology, and moreover only for ideogenic affects — those which are called up by perceptions and ideas.” He discusses how “powerful affects restrict association — the train ideas. People become ‘senseless’ with anger or fright. Only the group of ideas which provoked the affect persists in consciousness, and it does so with extreme intensity.”

He discusses how we can cry or shout or speak or act in anger to “blow off steam”, which reduces the excess cerebral excitation, but serve no other purpose beyond maintaining the “tendency to keep cerebral excitation constant”.

He concludes: “If, however, the affect can find no discharge of excitation of any kind along these lines, then the situation is the same with anger as with fright and anxiety. The intracerebral excitation is powerfully increased, but is employed neither in associative nor in motor activity. In normal people the disturbance is gradually levelled out. But in some, abnormal reactions appear, An ‘abnormal expression of the emotions’, as Oppenheim says, is formed.” This is the basis of Freud and Breuer’s theory of hysteria, and forms the neurological theoretical groundwork for Freud's later works.