Levitt, E. E., & Brady, J. P. Sexual preferences in young adult males and some correlates. Journal of Clinical Psychology, 1965, 21, 347-354. Levitt, E. E., & Hinesley, R. K. Some factors in the valences of erotic visual stimuli. Journal of Sex Research, 1967, 3, 63-68. Lifshitz, K. The average evoked cortical response to complex visual stimuli. Psychophysiology, 1966, 3, 55-68. Loiselle, R. H., & Mollenauer, S. Galvanic skin response to sexual stimuli in a female population. Journal of General Psychology, 1965, 73, 273-278. Marks, I. M., & Gelder, M. G. Transvestism and fetishism: Clinical and psychological changes during faradic aversion. British Journal of Psychiatry, in press. Marks, I. M., Rachman, S., & Gelder, M. G. Methods for assessment of aversion treatment in fetishism with masochism. Behaviour Research and Therapy, 1965, 3, 253-258. Martin, B. Expression and inhibition of sex motive arousal in college males. Journal of Abnormal and Social Psychology, 1964, 68, 307-312. Masters, W. H. Clinical significance of the study of human sexual response. Medical Aspects of Human Sexuality, 1967, 1, 14-20. Masters, W. H., & Johnson, V. E. Human sexual response. Boston: Little Brown, 1966. McConaghy, N. Penile volume change to moving pictures of male and female nudes in heterosexual and homosexual males. Behaviour Research and Therapy, 1967, 5, 43-48. McGuire, R. J., & Vallance, M. Aversion therapy by electric shock: A simple technique. British Medical Journal, 1964, 1, 151-153. Miller, D. R., & Swanson, G. E. Inner conflict and defense. New York: Holt, 1960. Minard, J. G. The measurement and conditioning of "perceptual defense" and response suppression. Unpublished doctoral dissertation, University of Colorado, 1963. Minard, J. G. Response-bias interpretation of "perceptual defense": A selective review and evaluation of recent research. Psychological Review, 1965, 72, 74-88. Mischel, W. Personality and assessment. New York: John Wiley, 1968. Mosher, D. L., & Greenberg, I. Females' affective responses to reading erotic literature. Journal of Clinical and Consulting Psychology, in press. Moss, T., & Gengerelli, J. A. Telepathy and emotional stimuli: A controlled experiment. Journal of Abnormal Psychology, 1967, 72, 341-348. Mussen, P. H., & Scodel, A. The effects of sexual stimulation under varying conditions on TAT sexual responsiveness. Journal of Consulting Psychology, 1955, 19, 90. Osgood, C. E., Suci, G. J., & Tannenbaum, P. H. The measurement of meaning. Urbana: University of Illinois Press, 1965. Pomeroy, W. B. Human sexual behavior. In N. L. Farberow (Ed.), Taboo topics. New York: Atherton Press, 1963. Pomeroy, W. B. The Masters-Johnson report and the Kinsey tradition. In R. Brecher & E. Brecher (Eds.), An analysis of human sexual response. New York: Signet Books, 1966. Rachman, S. Sexual disorders and behavior therapy. American Journal of Psychiatry, 1961, 118, 235-240. Rachman, S. Aversion therapy: Chemical or electrical? Behaviour Research and Therapy, 1965, 2, 289-299. Rachman, S. Sexual fetishism: An experimental analogue. Psychological Record, 1966, 16, 293-296. Rachman, S., & Hodgson, R. J. Experimentally-induced “sexual fetishism”: Replication and development. Psychological Record, 1968, 18, 25-27. Ramsey, G. V. The sexual development of boys. American Journal of Psychology, 1943, 56, 217-233. Raymond, M. J. Case of fetishism treated by aversion therapy. British Medical Journal, 1956, 2, 854-856. Scodel, A. Heterosexual somatic preference and fantasy dependency. Journal of Consulting Psychology, 1957, 21, 371-374. Skinner, B. F. Science and human behavior. New York: Macmillan, 1953. Solyom, L., & Beck, P. R. GSR assessment of aberrant sexual behavior. International Journal of Neuropsychiatry, 1967, 3, 52-59. Solyom, L., & Miller, S. A differential conditioning procedure as the initial phase of the behaviour therapy of homosexuality. Behaviour Research and Therapy, 1965, 3, 147-160. Tempone, V. J. Differential thresholds of repressers and sensitizers as a function of a success and failure experience. Unpublished doctoral dissertation, University of Texas, 1962. Thorpe, J. G., & Schmidt, E. Therapeutic failure in a case of aversion therapy. Behaviour Research and Therapy, 1964, 1, 357-362. Thorpe, J. G., Schmidt, E., & Castell, D. A comparison of positive and negative (aversive) conditioning in the treatment of homosexuality. Behaviour Research and Therapy, 1963, 1, 357-362. Ullmann, L., & Krasner, L. P. (Eds.) Case studies in behavior modification. New York: Holt, Rinehart & Winston, 1965. Valins, S. Emotionality and information concerning internal reactions. Journal of Personality and Social Psychology, 1967, 6, 458-463. Walters, R. H., Bowen, N. V., & Parke, R. D. Influence of looking behavior of a social model on subsequent looking behavior of observers of the model. Perceptual and Motor Skills, 1964, 18, 469-483. Whalen, R. P. Sexual motivation. Psychological Review, 1966, 73, 151-163. Wiggins, N., & Wiggins, J. S. A typological analysis of male preferences for female body types. Multivariate Behavioral Research, in press. Wiggins, J. S., Wiggins, N., & Conger, J. Correlates of heterosexual somatic preference. Journal of Personality and Social Psychology, 1968, 10, 82-90. Wolpe, J. Psychotherapy by reciprocal inhibition. Stanford: Stanford University Press, 1958. Zamansky, H. S. A technique for assessing homo sexual tendencies. Journal of Personality, 1956, 24, 436-448. Physiological Measures of MARVIN ZUCKERMAN Department of Psychology In an article about sex research which appeared in the N. Y. Times, Gebhard is quoted as saying to Masters during an automobile trip, "Watch where you're going, Bill. If you get us all killed, there goes sex research in the United States" (Buckley, 1969, p. 106). Although Gebhard's statement is somewhat exaggerated, it is true that the Kinsey Institute and the Reproductive Biology Research Foundation represent the major sources of scientific information about human sexual patterns. However, many investigators are now becoming active in this field, and it may be helpful to survey some of the physiological methods in current use. This article will deal with quantifiable physiological methods of measuring human sexual arousal. Many of these methods are still in developmental stages, and details about them were provided by generous investigators. It is hoped that by facilitating scientific communication, more research will be stimulated in this vital area. Many important questions seem to be awaiting the development of appropriate methodology. One example which involves an area of public debate is the question of pornography. Every investigation of this problem from a legal or social standpoint has concluded with the statement that not enough scientific information is available. It is obvious that scientists cannot answer questions such as how arousing pornography is, or who is most aroused by pornography, until they can decide on reliable methods for measuring sexual arousal. Theoretical questions, such as those posed by Hardy (1964), must also await the development of suitable methodology for measuring sexual arousal. Whalen (1966) has made a useful distinction between sexual arousal (the momentary or current level of sexual excitement) and sexual arousability ("an individual's characteristic rate of approach to orgasm as a result of sexual stimulation") (p. 152). The distinction is similar to that made between state and trait by other investigators concerning other emotions (Cattell & Scheier, 1961; Spielberger, 1966; Zuckerman, Persky, & Link, 1967). Zuckerman et al. (1967) suggested that a trait may be measurable as the average and variation in a series of state measures. If this were applied to sexual arousability, it would be possible to define arousability by a series of measures of sexual arousal to standard stimulation. Beach (1956) reported high reliabilities for various behavioral indices of sexual arousal in rats. Comparable data on humans is simply not available. Sexual arousability could be measured by behavioral and verbal report measures. Latency to orgasm, frequency of orgasm, and subjective estimates, of arousal are some alternatives to physiological recording. However, physiological measures offer some obvious advantages in their objectivity, continuous time sampling, and the fact that they can be used to measure arousal without necessarily inducing orgasm. Although some mechanical devices have been developed for inducing orgasm in a somewhat standard fashion (Masters & Johnson, 1966; Sobrero, Stearns, & Blair, 1965), most measurements which rely on orgasm introduce many uncontrolled variables, the least of which is movement. The social nature of conventional sexual stimulation, the influence of the setting in which orgasm is induced, and volunteer selection are all problems in this kind of experiment. Psychological or visual and auditory stimuli are more easily standardized and allow the researcher to sample a wider variety of subjects. Furthermore, it is questionable that arousal can be measured by orgastic ejaculation since the two may depend on different neural mechanisms. This problem will be discussed later. It should be pointed out that the tremendous fund of data collected by Kinsey and his coworkers (Kinsey, Pomeroy, & Martin, 1948; Kinsey, Pomeroy, Martin, & Gebhard, 1953) were based on retrospective reports. The data presented by Masters and Johnson (1966) are physiological and anatomical, but not very quantitative. In describing the course of physiological reactions during the various stages of arousal, Masters and Johnson reported modal reactions and ranges of reactions with little indication of normal variation. Some of the changes described may be intrinsically difficult to measure, but most, such as blood volume changes, temperature changes, muscle tension, hyperventilation, tachycardia, and sweating, are accessible to measurement by standard psychophysiological techniques. Special applications of these techniques will be described later in this paper. The description of modal patterns is useful, but more quantitative specificity is necessary in studying relationships between variables and comparing individuals or groups of individuals. CENTRAL NERVOUS SYSTEM Sexual arousal is undoubtedly mediated through the central and autonomic nervous systems and may also involve the pituitary gonadotropic and gonadal system.1 Money (1961) has summarized: among the coordinates of sexual function there are three: local genital surfaces, the brain, the hormones, any of which can fail in its contributions without total destruction of sexual function. . . . Nonetheless, it is evident that loss of any one of the three constituents is an immense handicap to effective sexual functioning. (p. 1396) Although the gonadotropic and gonadal hormones have been shown to play an essential role in the anatomical development of the sexual systems, their role in sexual arousal in man is less clearly understood. Beach (1958) noted species and sex differences in the degree to which sexual arousal depends on the neocortex and hormones. The evolutionary trend is toward more stress on the neocortex and less on the hormones. MacLean (1965) has discussed the psychosexual functions of the brain. Visual and olfactory senses are important in the initial stimulation of sexual arousal, and MacLean suggested that the visual sense has become more important in the course of evolution. However, the importance of visual and auditory stimulation in the displays and calls of mating birds would suggest that the crucial roles of these senses are not confined to higher species of mammals. More specific sexual arousal centers have been found in the limbic system of the squirrel monkey, using the method of intracranial stimulation. Penile erections were elicited by stimulation of hippocampal projections to parts of the septum, anterior thalamus and hypothalamus; parts of the Papex circuit (mamillary bodies, mamillothalamic tract, anterior thalamic nuclei, and anterior cingulate gyrus); and parts of the medial orbital gyrus, medial dorsal nucleus of the thalamus, and regions of their connections. The medial part of the medial dorsal nucleus and medial septopreoptic region are said to be modal points for erection. Stimulation in the septum and rostral diencephalon, which results in erection, is also noted to be associated with afterdischarges in the hippocampus, during which time erections become throbbing in character and reach maximum size. Following these hippocampal after discharges, the monkeys appear to be calm and placid for some time. There is a strong suggestion that the hippocampal discharges are linked to the phenomenon of orgasm and postorgastic decline of arousability in the male; they are not, however, associated with ejaculation. Stimulation in the thalamus of other points within and bordering on the caudal intralaminar region and along the course of the spinothalamic pathway elicit seminal discharge with motile sperm and quasipruritic scratching of the genitalia. The seminal discharge could occur without the appearance of throbbing penile erection. Beach (1956) suggested a distinction between a sexual arousal mechanism (SAM) and the intromissive and ejaculatory mechanism (IEM) in the male,2 and MacLean's evidence shows the neural separation of these mechanisms. Sobrero et al. (1956) used a vibrating cup applied with gentle pressure to the glans penis to obtain semen samples from schizophrenic males and males with infertility problems. Although ejaculation was eventually induced in all 40 infertile males, "no full erection was ever observed, although in some instances a partial, very soft erection was observed at the time of ejaculation" (p. 767). Similar results were obtained with five normal subjects. Only five of these 45 subjects reported erotic fantasies or orgasmic feelings. In Hohmann's (1966) study of the effects of spinal cord lesions on emotional feelings, 15 of the 25 subjects were still able to have erections, but only three reported ejaculation, and four reported the experience of orgasm. These data provide behavioral evidence for the separation of SAM and IEM. Other findings relevant to the independence of ejaculation and orgasm have been discussed by Beach (1966). The implication of the independent functioning of these systems is that latency of ejaculation cannot be equated with penile erection as alternate indices of sexual arousal. The IEM seems to be more dependent on autonomic and sensory feedback than the SAM. 2 In the later articles Beach refers to these as the arousal mechanism (AM) and consummatory mechanism (CM). |