We shall see later that the neural model of sexual arousal (SA) also comprises inhibitory components
We shall first consider Freud’s account of sexual excitement, mainly on the basis of “Three Essays on the Theory of Sexuality” (Freud, 1905). When he started elaborating his theory of sexual excitement, Freud was focusing on a phenomenon that is, at least in part, directly observable, including genital, cardiovascular and respiratory manifestations. By contrast, a sexual drive cannot be directly observed; it is a construct inferred from psychoanalytic (or other) investigation with an aim to explain various phenomena, in particular sexual excitement. “You never experience a drive directly. […] The feeling of thirst is not itself a drive, which is not something you experience; rather, the concept of thirst explains why you feel thirst when you need water” (Solms and Zellner, 2012). Thus, from an epistemological viewpoint, there is a sharp distinction between the concepts of sexual excitement and of sexual drives.
Regarding sexual excitement, Freud wrote: “This apparatus [i.e., the somatic and psychical sexual apparatus] is to be set in motion by stimuli, and observation shows us that stimuli can impinge on it from three directions: from the external world by means of the excitation of the erotogenic zones […], from the organic interior by ways which we have still to explore, and from mental life, which is itself a storehouse for external impressions and a receiving-post for internal excitations.
All three kinds of stimuli produce the same effect, namely a condition described as “sexual excitement”, which shows itself by two sorts of indication, mental and somatic” (Freud, 1905)
Elaborating on the feeling of tension, Freud further described the peculiar mixture of unpleasure and pleasure associated with sexual excitement: “I must insist that a feeling of tension necessarily involves unpleasure. What seems to me decisive is the fact that a feeling of this kind is accompanied by an impulsion to make a change in the psychological situation, that it operates in an urgent way which is wholly alien to the nature of the feeling of pleasure. If, however, the tension of sexual excitement is counted as an un-pleasurable feeling, we are at once brought up against the fact that it is also undoubtedly felt as pleasurable. […] How, then, are this unpleasurable tension and this feeling of pleasure to be reconciled?” (Freud, 1905). Could it be that, in order to motivate human beings to advance from low to high excitement and ultimately to orgasm, two incentives operate, i.e., (i) the pleasure of excitement, a pleasure that grows as excitement increases; and (ii) the tension which the individual will work to ease, thereby obtaining additional pleasure.
One of the essential tenets of the Freudian theory of sexual excitement is the concept of erotogenic zones: “[…] excitations of two kinds arise from the somatic organs, based upon differences of a chemical nature. One of these kinds of excitation we describe as being specifically sexual, and we speak of the organ concerned as the “erotogenic zone” of the sexual component instinct arising from it. […] in scopophilia and exhibitionism the eye corresponds to an erotogenic zone” (Freud, 1905). As shown below, in most functional neuroimaging studies of sexual excitement, investigators have used visual sexual stimuli (VSS), thus relying on scopophilic tendencies of both healthy subjects and patients to induce sexual excitement.
Not only did Freud elaborate a ilove discount code theory of sexual excitement, but he also proposed a theory of its inhibition. The latency period, that extends approximately from 6–7 to 10–11 years of age, has a great importance in this regard: “It is during this period of total or only partial latency that are built up the mental forces which are later to impede the course of the sexual instinct and, like dams, restrict its flow-disgust, feelings of shame and the claims of aesthetic and moral ideals” (Freud, 1905).