SexualArousalinMen:AReviewandConceptualAnalysis ErickJanssen PII: S0018-506X(11)00063-8 DOI: doi: 10.1016/j.yhbeh.2011.03.004 Reference: YHBEH3177 Toappearin: HormonesandBehavior Receiveddate: 14September2010 Reviseddate: 23January2011 Accepteddate: 3March2011 Please cite this article as: Janssen, Erick, Sexual Arousal in Men: A Review and Con- ceptual Analysis, HormonesandBehavior (2011), doi: 10.1016/j.yhbeh.2011.03.004 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. ACCEPTED MANUSCRIPT T P Sexual Arousal in Men: I R A Review and Conceptual Analysis C S U Erick Janssen, Ph.D. N The Kinsey Institute for Research in Sex, Gender, and Reproduction A Indiana UniversitMy, Bloomington, Indiana D E T P E C C RUNNING HEAD: Sexual Arousal in Men A Correspondence: Erick Janssen The Kinsey Institute for Research in Sex, Gender, and Reproduction Indiana University Morrison Hall 313 1165 East Third Street Bloomington, Indiana 47405-2501 Phone: (812) 855-7686 Fax: (812) 855-8277 E-mail: [email protected] ACCEPTED MANUSCRIPT Sexual Arousal in Men – 2 ! Abstract Sexual arousal is an emotional/motivational state that can be triggered by internal and external T stimuli and that can be inferred from central (including verbal), peripPheral (including genital), I and behavioral (including action tendencies and motor preparation) responses. This article, while R focusing on sexual arousal in men, provides a conceptual anaClysis of this construct, reviews S models of sexual arousal, and discusses the usefulness of perspectives derived from motivation U and emotion research in improving our understanding of its determinants and behavioral N correlates. In this, it considers the role of genital feedback in men’s subjective sexual arousal and A M the connections between sexual arousal and sexual desire. Future research and definitions may increasingly focus on its central integratiDve functions (as opposed to its input and output characteristics). Yet, the study of sexEual arousal can be expected to continue to benefit from the T measurement of its genital, verbal, and behavioral components. Instances of discordance between P response components suggesEt that they are, at least in part, under the control of different C mechanisms, and it is proposed that a better understanding of sexual arousal will prove C contingent on a better understanding of such mechanisms and the conditions under which they A converge and diverge. ACCEPTED MANUSCRIPT Sexual Arousal in Men – 3 ! "Coitus is impossible for man without erection of the penis, and that requires his sexual arousal." T P (Squier, 1938, p. 119) I R C Defining sexual arousal S The use of the term sexual arousal in the English-language medical and scientific literature can U be traced back to the 1930s (e.g., Murchison & Harden, 1933, Squier, 1938)1. Phrases and N expressions that refer to arousing the sexual impAulse (e.g., Ellis, 1903), arousing erotic M sensations (Kelly, 1930), arousing passion (e.g., Gurley, 1909; Malchow, 1907), and arousing desire (Nasher, 1916) were commonly uDsed around the turn of the century, but gradually E disappeared during the 1930s and 1940s. Thus, the history of the term sexual arousal involves a T transition from the predominant use of a verb (to arouse) to that of a noun (sexual arousal). P However, as was the case foEr the verb, the noun could refer to psychological processes, C physiological processes, or a combination of the two, and it often was left to the reader to infer C the specifics from the context in which the term was used. A Although the past century has seen a number of important advances in the study of human sexual response, the current literature is still rife with ambiguity about what exactly is being felt or observed when someone is sexually aroused, and sex researchers have yet to arrive at a consensus on how to best define this state. Most would probably agree that in developing a definition one needs to address questions regarding the importance of peripheral (including genital) and central (including experiential) processes. Yet, definitions tend to be challenged !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! 1This conclusion is based on searches using PsycInfo, MedLine, Google Books, as well as the collections of the Kinsey Institute. The term sexual excitement (in English but also in German, for example), although not included in these searches, may have predated the use of the term sexual arousal. ACCEPTED MANUSCRIPT Sexual Arousal in Men – 4 ! rather than informed by findings from psychophysiological studies that show the relative independence of peripheral and central indicators of sexual arousal2. Although correlations in men between genital responses and self-reports of sexual arousal are, onT average, substantial P (Chivers et al., 2010), large variability can be found between studies, with some finding almost I R no, or at best weak, associations between the two (e.g., Both et al., 2004; Janssen et al., 2009; C Van Lankveld & v.d. Hout, 2004). Indeed, it can be argued that the introduction of S psychophysiological methods in the 1960s – allowing fUor first time the concurrent measurement N of genital and subjective reactions – is largely responsible for initiating, or at least invigorating, A the continuing debate on what constitutes sexual arousal. M In addition to variations in correlations between subjective and physiological measures, D numerous psychophysiological studies have revealed response patterns in men that defy simple, E unidimensional conceptualizations of sexual arousal (e.g., Bach, Brown, and Barlow, 1999; T P Cranston-Cuebas & Barlow, 1990; Delizonna et al., 2001; George et al., 2006; Van Lankveld E and v.d. Hout, 2004). For example, experimentally induced distraction (e.g., by having men C engage in mental arithmetic) during erotic film presentations has been found to decrease C erections but not suAbjective sexual arousal (Van Lankveld & v.d. Hout, 2004). Also, providing men with false feedback (e.g., by informing them that their erections do not measure up to those of the other subjects) has been found to decrease genital responses but not subjective arousal during subsequent stimulus presentations (Bach, Brown, & Barlow, 1999). More divergent patterns have also been reported. For example, Both, Laan, & Everaerd (2010) found that the !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !A number of relatively well-validated instruments exist to assess genital responses in men, including measures of penile circumference, volume, and rigidity. For the assessment of experiental aspects of sexual arousal, most researchers rely on the use of questionnaires, which may include questions such as “how sexually aroused do you currently feel? See Janssen, Prause, & Geer (2007) for a critical review of ! the measurement of genital responses and subjective sexual arousal in men. ACCEPTED MANUSCRIPT Sexual Arousal in Men – 5 ! repeated exposure to a sexual stimulus resulted in habituation in men’s subjective sexual arousal. Genital responses, in contrast, increased over trials. In addition to psychological and physiological indicators, or subTjective and genital P response components, sexual arousal has been described in behavioral terms. Beach (1942), who I R was one of the first to use the term sexual arousal in the animal literature, mainly referred to it in C motivational terms, as something that leads to mating and that can be measured in terms of the S frequency or latency of copulatory behaviors. The reliaUnce in animal studies on behavior as an N index of sexual arousal may at least in part be attributed to the challenges involved in assessing A genital and subjective responses in animal models. In contrast, there is less of a tradition of using M behavioral measures in human studies of sexual arousal. D So, what is sexual arousal? In short, we don't know. Although its main indicators E (including, for men, penile erection) may be well recognized, we do not know what is necessary T P or sufficient to label someone as being sexually aroused. Most men may be capable of having E erections. Most men may know what it feels like to be sexually aroused. But despite the C generally high correlations between erections and subjective arousal (Chivers et al., 2010), men C do not always repoArt feeling sexually aroused when they have an erection, nor do they always experience an erection when they feel aroused. Erections occur during sleep (in particular Rapid- Eye-Movement or REM sleep), and have been studied both during the night and during daytime naps (e.g., Gordon & Carey, 1995). However, generally speaking, sleep-related erections are dissociated from erotic dream content or the experience of subjective sexual arousal (e.g., Karacan, 1982). As another example, men may experience erections in situations that are, at least at face value, devoid of sexual meaning, including accidents (Janssen et al., 2008). Consistent with this, psychophysiological studies have found that men can get erections to, for example, ACCEPTED MANUSCRIPT Sexual Arousal in Men – 6 ! rape films while experiencing little to no subjective arousal (Janssen et al., 2002). The opposite has been observed as well. For example, some men report experiencing sexual arousal in the absence of erections when they visit a strip club (Janssen et al., 2008). PTsychophysiological P studies, too, suggest that men can feel subjectively aroused in the absence of a genital response. I R For example, Janssen et al. (2009) found, in a sexually functional community sample of men, C that about one-quarter of the participants met the criteria of a ‘nonresponder’ (penile rigidity of S <10%). Cluster analyses confirmed differences in genitUal response, but low and high genital N responders did not differ in subjective sexual arousal. Findings like the ones discussed above A underscore the complexities involved in establishing the necessary and sufficient conditions for M sexual arousal. D Some have proposed that the most parsimonious approach to defining sexual arousal, at E least when it comes to men, is to discount subjective feelings and equate it with penile erection T P (Agmo, 2008). However, not only is this position unlikely to take our understanding of sexual E arousal to new levels – after all, erections can be studied without the need to invoke higher-level C constructs such as sexual arousal – it is also based on the empirically unsubstantiated assumption C that a man’s subjecAtive state of sexual arousal finds its roots in his genitalia and, thus, that the “crucial component of the term 'subjective arousal' is genital blood flow” (Agmo, 2008, p. 313). In a less extreme form, Sachs (2000, 2007) has proposed that penile erection in a sexual context can be considered a reliable and valid indicator of male sexual arousal. Although this position acknowledges that not all erections are sexual, it invites circular reasoning as it transfers definitional challenges to the question of what makes a context “sexual.” In contrast, other researchers (e.g., Rosen & Beck, 1988, cf. Janssen & Everaerd, 1993) have proposed that sexual arousal cannot be defined adequately "without highlighting the critical role of cognitive labeling ACCEPTED MANUSCRIPT Sexual Arousal in Men – 7 ! and subjective experience" (p. 28). However, this position ignores the possibility that sexual arousal can be activated (and even impact behavior) at a level that fails to translate into the conscious experience of "feeling" aroused (e.g., Janssen et al., 2000). T P Opinions not only differ in how to best define sexual arousal, scholars also disagree on I R how important definitions are to scientific progress. Sachs (2007), who presents a comprehensive C overview of definitions of sexual arousal, believes that advances in the study of this construct are S dependent upon improvements in our terminology and Udefinitions. Yet, the history of related N areas of scientific inquiry, including that of human emotion, suggests that explicit definitions A often "are a result of scientific investigations, not a prerequisite for them" (Ohman, 1987, p.81). M The position taken in this article is consistent with the latter position, in that any definition that D assigns more importance to one indicator of sexual arousal over another, at this stage, can be E expected to constrain scientific progress. T P Consistent with positions held in both emotion theory (e.g., Lang, 1967) and affective E neuroscience (e.g., LeDoux, 1996; Panksepp, 1998), sexual arousal may be described as an C emotional/motivational state that can be triggered by internal and external stimuli and that can be C inferred from centrAal (including verbal), peripheral (including genital), and behavioral (including action tendencies and motor expressions) responses. Although future research – in particular research using brain imaging and EEG techniques – may reveal a need for definitions to incorporate its central integrative functions (as opposed to its input and output characteristics; cf. Lang, 2010, Panksepp, 1998), at present the study of sexual arousal continues to benefit from the measurement of its genital, verbal, and behavioral components. Instances of discordance between the various indicators of sexual arousal suggest that, at least to some degree, they are under the control of different mechanisms (cf. Bancroft, 1989). The position taken in this article is that, ACCEPTED MANUSCRIPT Sexual Arousal in Men – 8 ! ultimately, our efforts to arrive at an empirically informed and conceptually sound definition of sexual arousal will prove contingent on a better understanding of such mechanisms and the conditions under which they converge and diverge. T P Models of sexual arousal I R Whereas the previous section emphasizes its multifaceted nature, most existing models of human C sexual arousal tend to treat it as a unified construct. Early models (e.g., Ellis, 1906; Moll, S 1908/1912) described processes relevant to sexual arouUsal in relatively nonspecific terms, N distinguishing two or more phases of increasing levels of sexual tension (e.g., "tumescence" in A Ellis' words) and release ("detumescence"). Masters and Johnson's (1966) four-stage model of M sexual response, while reminiscent of Moll's (1908/1912) 'curve of voluptuousness,' was the first D to describe, based on empirical research, the genital and extragenital responses that occur in E humans during sexual behavior. However, Masters and Johnson did not specifically address the T P subjective experience of sexual arousal in their model. Furthermore, Masters and Johnson's E model implies that the sexual response involves some natural sequence of physiological events C that is activated automatically as long one is presented with adequate sexual stimulation. C However, they did Anot define adequate sexual stimulation (Janssen & Everaerd, 1993). In fact, their approach to the term is circular: Effective stimulation produces a response and a response is evidence for effective stimulation. Kaplan (1977, 1979), who introduced a modification of Masters and Johnson’s model, replaced their first stage by the more psychological phase of ‘desire’, dropped their 'plateau phase,' but she retained the 'excitement' and 'orgasm' phases. Although a number of other models relevant to sexual arousal in men have been proposed over the years (e.g., Bancroft, 1989; Byrne, 1977), only a few are based on empirical research. One of the first of such models was introduced by Barlow (1986). His model was inspired by a ACCEPTED MANUSCRIPT Sexual Arousal in Men – 9 ! series of psychophysiological studies (see Barlow, 1986 and Cranston-Cuebas and Barlow, 1990, for review) that revealed a number of factors differentiating men with psychogenic erectile problems from men without such problems. The model proposes that seTxual responses form P either a positive or a negative feedback loop, which start with the perception of an explicit or I R implicit demand for sexual performance. This perception triggers positive or negative affective C evaluations which both activate autonomic arousal. Increased autonomic arousal enhances S attention for those features of the sexual situation that aUre most salient. Continued processing of N sexually-relevant cues produces genital response, and ultimately leads to sexual approach A behavior. Continued processing of nonsexual cues (e.g., consequences of not responding, a form M of self-generated distraction) interferes with sexual arousal and ultimately leads to avoidance D behavior. E Barlow’s model thus emphases the role of affective responses that are triggered by sexual T P stimuli and attention that is directed by those affective responses and that needs to be maintained E in order to obtain higher levels of sexual arousal. While its main strength lies in how it captures C the difference between functional and dysfunctional patterns of sexual response, the model does C not address the queAstion of how dysfunctional patterns come about, nor does it provide a clear basis for predictions regarding discordance in response patterns. Wiegel, Scepkowski, and Barlow (2007) presented an expansion of the model that incorporates roles for schemas, negative/positive expectancies, and a stronger emphasis on the negative effects of self-focused attention. In addition, they discuss a number of biopsychosocial variables that may predispose an individual to develop sexual dysfunctions. An interesting modification involves the proposed partial independency in the effects of positive and negative affect. Positive affect, or its absence, is proposed to be particularly relevant to subjective sexual arousal, whereas negative affect is