Modulation of spinal reflexes by sexual films of increasing intensity

Sexual arousal can be viewed as an emotional state generating sex-specific autonomic and general somatic motor system responses that prepare for sexual action. In the present study modulation of spinal tendious (T) reflexes by sexual films of varying intensity was investigated. T reflexes were expected to increase as a function of increased film intensity. Through use of a between-subjects design, participants were exposed to three erotic films of low, moderate, and high intensity or to three films of moderate intensity. Self-report and genital data confirmed the induction of increasing versus stable levels of sexual arousal. Exposure to the films of increasing intensity resulted in increasing T reflexes. The results indicate that T reflex modulation is sensitive to varying levels of sexual arousal and may be of use in research on behavioral mechanisms underlying appetitive motivation.     

Modulation of spinal reflexes: Arousal, pleasure, action

The human startle reflex is reliably modulated by the affective valence of foreground pictures, with larger reflexes elicited when viewing unpleasant relative to pleasant scenes. If this modulation is due to priming of the defensive startle reflex by an aversive foreground, a different pattern should occur for a reflex that is not inherently defensive in nature. In the current study, affective modulation was investigated using the spinal tendinous (T) reflex, which is well documented as sensitive to differences in arousal and is involved in actions that are both appetitively and defensively motivated. As such, T reflexes elicited during unpleasant pictures were not expected to be augmented relative to those elicited in the context of pleasant pictures. Results showed that T reflexes were facilitated during processing of arousing stimuli – either pleasant or unpleasant relative to low-arousal neutral materials. These effects of emotional stimuli on T-reflex amplitude are consistent with the hypothesis that motivational priming underlies affective reflex modulation.     

Assessment of female sexual arousal: Response specificity and construct validity

Specificity of vaginal pulse amplitude and vaginal blood volume in reaction to visual sexual stimuli was investigated by comparing responses to sexual, anxiety-inducing, sexually threatening, and neutral film excerpts. Subjective sexual arousal, body sensations, emotional experience, skin conductance, and heart rate were monitored along with the genital measures. Self-report data confirmed the generation of affective states as intended. Results demonstrated response specificity of vaginal vasocongestion to sexual stimuli. In terms of both convergent and divergent validity, vaginal pulse amplitude was the superior genital measure. Skin conductance discriminated among stimuli only to a small degree, whereas heart rate failed to discriminate among stimuli altogether.     

Affective startle modulation in anticipation and perception

Startle modulation was investigated as participants first anticipated and then viewed affective pictures in order to determine whether affective modulation of the startle reflex is similar in these different task contexts. During a 6-s anticipation period, a neutral light cue signaled whether the upcoming picture would portray snakes, erotica, or household objects; at the end of the anticipatory period, a picture in the signaled category was viewed for 6 s. Male participants highly fearful of snakes were recruited to maximize emotional arousal during anticipation and perception. Results indicated that the startle reflex was potentiated when anticipating either unpleasant (phobic) or pleasant (erotic) pictures, compared to neutral stimuli, whereas during perception, reflexes were potentiated when viewing unpleasant stimuli, and reduced when viewing pleasant pictures. The startle reflex is modulated by hedonic valence in picture perception, and by emotional arousal in a task context involving picture anticipation.     

Gastric myoelectrical activity as an index of emotional arousal.

Autonomic nervous system parameters such as electrodermal activity, heart rate, and facial EMG have been utilized extensively as measures of emotional arousal. One measure that has rarely been employed in this setting is gastric myoelectrical activity, despite the fact that "gut feelings" have an obvious and even profound role in everyday emotional life. It has been shown that the gastrointestinal system changes wall tonus and contraction rate during stressful tasks. However, the effects of emotionally salient stimuli on gastrointestinal motility have scarcely been studied. In the current study, emotional film clips designed to elicit happiness, disgust, fear, sadness, or no emotion (neutral) were presented to 16 normal participants. Electrogastrogram (EGG), skin conductance, and heart rate were measured while the participants viewed the film clips, and participants rated subjective arousal intensity and pleasantness of the film clips. We found that emotional film clips reliably induced the intended subjective feeling states. Also, EGG peak amplitudes in fear, disgust, sadness and happiness were higher than in the no emotion condition. There was a strong positive correlation (r=0.64) between EGG peak amplitude and subjective ratings of arousal. This is the first evidence that gastric myoelectrical activity is strongly correlated with arousal ratings to emotionally salient stimuli, and it suggests that EGG may add useful information about how the body contributes to the phenomenology of emotion and feeling.     

Postauricular reflex responses to pictures varying in valence and arousal

Reflexes are modulated by emotions. Much research has revealed that the startle reflexive eyeblink response is modulated by emotion, particularly in response to pictures of emotional scenes. Investigations of other reflexes are limited. Recently, research suggested that the postauricular reflex in response to a startling noise was modulated by emotion. In particular, pleasant stimuli enhanced the postauricular reflex. However, these first investigations were limited: One experiment demonstrated only a marginal difference between the pleasant stimuli and neutral stimuli and the other lacked the typical neutral scene comparison. The present experiment was designed to assess whether significant emotion versus neutral differences would occur. Results demonstrated that pleasant stimuli, regardless of arousal level, evoked larger postauricular reflex activation than neutral and unpleasant emotional stimuli.     

Postauricular reflexes elicited by soft acoustic clicks and loud noise probes: Reliability,prepulse facilitation,and sensitivity to picture contents

The startle blink reflex is facilitated during early picture viewing, then inhibited by attention during pleasant and aversive pictures compared to neutral pictures, and finally potentiated during aversive pictures specifically. However, it is unclear whether the postauricular reflex, which is elicited by the same loud acoustic probe as the startle blink reflex but enhanced by appetitive instead of defensive emotion, has the same pattern and time course of emotional modulation. We examined this issue in a sample of 90 undergraduates using serially presented soft acoustic clicks that elicited postauricular (but not startle blink) reflexes in addition to standard startle probes. Postauricular reflexes elicited by both clicks and probes correlated during food and nurturant contents, during which they were potentiated compared to neutral pictures, suggesting clicks effectively elicit emotionally modulated postauricular reflexes. The postauricular reflex was initially facilitated during the first 500 ms of picture processing but was larger during pleasant than neutral pictures throughout picture processing, with larger effect sizes during the latter half of picture processing. Across reflexes and eliciting stimuli, measures of emotional modulation had higher coefficient alphas than magnitudes during specific picture contents within each valence, indicating that only emotional modulation measures assess higher‐order appetitive or defensive processing.     

Frontal alpha asymmetry and sexually motivated states

Anterior alpha asymmetry of electroencephalographic (EEG) signals has been suggested to index state approach (or avoidance) motivation. This model has not yet been extended to high approach‐motivation sexual stimuli, which may represent an important model of reward system function. Sixty‐five participants viewed a neutral and a sexually motivating film while their EEG was recorded, and reported their sexual feelings after each film. Greater alpha power in the left hemisphere during sexually motivated states was evident. A positive relationship between self‐reported mental sexual arousal and alpha asymmetry was identified, where coherence between these indicators was higher in women. Notably, coherence was stronger when mental versus physical sexual arousal was rated. Alpha asymmetry appears to offer a new method for further examining this novel coherence pattern across men and women.     

Mood-congruent memory in daily life: Evidence from interactive ambulatory monitoring

Evidence from the psychological laboratory indicates that emotional states tend to facilitate the encoding and retrieval of stimuli of the same emotional valence. To explore mood-congruent memory and the role of arousal in daily life, we applied a new interactive ambulatory technique. Psychophysiological arousal as indexed by non-metabolic heart rate, self-reported emotions and situational information were assessed during 24-h recordings in 70 healthy participants. The emotional state was used to trigger word list presentations on a minicomputer. Our results show that psychophysiological arousal at the time of encoding enhanced the recall of negative words in negative emotional conditions, whereas low psychophysiological arousal facilitated recall of positive words. In positive contexts, mood congruency was more prominent when arousal was low. These results demonstrate how automated experimentation with an ambulatory technique may help to assess emotional memory in real-world contexts, thus providing new methods for diverse fields of application.     

Trait anxiety and prior exposure to non-stressful stimuli: effects on psychophysiological arousal and anxiety.

Arousal and anxiety responses to stressful stimulation are products of multiple factors that may include the physiological, behavioral, cognitive, affective, trait, and state components of our six-system model, as well as mediational and non-mediational perspectives. Within the context of this model, the present experiment examined the effects of prior exposure to neutral stimuli on arousal and anxiety responses to stress. High and low trait-anxious participants were randomly assigned to one of three prior exposure conditions in which they were exposed to stressful stimuli following exposure to: (a) neutral, non-stressful stimulation in the same modality (the Intramodality Prior Exposure or IPE experimental condition); (b) neutral stimuli in a different modality (the Cross-modality Prior Exposure or CPE control condition); or (c) a rest period (the Stress Only or SO control condition). Results showed that low trait anxious subjects had consistently larger arousal and anxiety responses to stress than did highs and that prior exposure to certain same-modality neutral stimuli reduced responses to subsequent stressors. In addition, arousal was greater in response to cognitive than to affective and in response to non-mediational than mediational conditions. Results are discussed in terms of the inverted-U arousal function and of the six-system model and its implications for understanding anxiety and arousal.     

The influence of autonomic arousal and semantic relatedness on memory for emotional words.

Increased memory for emotional stimuli is a well-documented phenomenon. Emotional arousal during the encoding of a stimulus is one mediator of this memory enhancement. Other variables such as semantic relatedness also play a role in the enhanced memory for emotional stimuli, especially for verbal stimuli. Research has not addressed the contributions of emotional arousal, indexed by self-report and autonomic measures, and semantic relatedness on memory performance. Twenty young adults (10 women) were presented neutral-unrelated words, school-related words, moderately arousing emotional words, and highly arousing taboo words while heart rate and skin conductance were measured. Memory was tested with free recall and recognition tests. Results showed that taboo words, which were both semantically related and high arousal were remembered best. School-related words, which were high on semantic relatedness but low on arousal, were remembered better than the moderately arousing emotional words and semantically unrelated neutral words. Psychophysiological responses showed that within the moderately arousing emotional and neutral word groups, those words eliciting greater autonomic activity were better remembered than words that did not elicit such activity. These results demonstrate additive effects of semantic relatedness and emotional arousal on memory. Relatedness confers an advantage to memory (as in the school-words), but the combination of relatedness and arousal (as in the taboo words) results in the best memory performance.     

Modulation of the acoustic startle reflex by emotionally-toned film-clips.

It has been widely reported that the eyeblink component of the acoustic startle reflex can be modulated by emotionally-toned slide stimuli; pleasant slides reduce eyeblink amplitudes whereas unpleasant slides enhance them. The present study examines the modulation of the acoustic startle reflex by short (2-min) film-clips classified as pleasant, unpleasant or neutral, on the basis of subjective ratings. These film-clips were also evaluated with respect to their test-retest reliability in producing affective states as well as modulating startle reflexes. Overall, results showed significant reduction of startle during pleasant clips and augmentation during unpleasant clips. However, on first showing, one of the two unpleasant clips (a medical demonstration film depicting details of toe surgery) actually inhibited the startle reflex rather than augmented it. This is discussed in terms of the proposition that only stimuli which arouse fear can be guaranteed to augment startle; stimuli that are repulsive may produce perceptual and emotional 'blunting' that reduces startle amplitude.     

Psychoendocrine response to sexual arousal in human males

The hypothesis is tested that luteinizing hormone (LH) and follicle stimulating hormone (FSH( may be released from the anterior pituitary in response to a psychological state of sexual arousal. LH levels in 10 male volunteers were found to be higher after viewing a sexually arousing film than after a control film. The magnitude of LH response was found to be positively correlated with the subjective evaluation of sexual arousal. FSH levels tended in the same direction bu the predominant and unexpected finding for this hormone was that levels were consistently lower during the first session, when anxiety was high, and higher during the second session, when anxiety was less, whether control or stimulus film had been shown. This study is analogous to those demonstrating the responsiveness of other anterior pituitary hormones to specific psychological states.     

Pictures as prepulse: Attention and emotion in startle modification

The effects of an emotional stimulus prepulse on probe startle response were examined here. Pleasant, neutral, and unpleasant pictures were viewed for 6 s, and an acoustic startle probe was presented either 300, 800, 1,300, or 3,800 ms after slide onset, or 300 or 3,800 ms after slide offset. Blink magnitude and onset latency demonstrated (a) an early (prepulse) inhibition effect in which reflexes elicited immediately after slide onset were smaller than reflexes elicited later in the viewing interval, and (b) affective modulation, in which unpleasant stimuli prompted larger reflexes than pleasant. Interactive effects of probe time and picture valence indicated attention/arousal effects early and pleasantness effects late in the picture interval. Effects of both attention and emotion can be simultaneously measured using this startle-probe paradigm, encouraging its use in both basic and clinical contexts.     

Psychophysiological response patterns to positive and negative film stimuli

The aim of the present study was to investigate differential emotional response patterns to film stimuli by multimodal assessment of mood ratings, perception of bodily sensations, salivary cortisol, autonomic variables and facial electromyogram (EMG). Film stimuli, chosen to elicit positive and negative emotional states, were presented to 12 subjects with general anxiety disorder and 12 controls. Changes in mood, bodily sensations, autonomic activity (heart rate, respiration rate and skin conductance), facial EMG activity (corrugator and zygomatic muscle region) and salivary cortisol were measured. Analyses revealed differential changes in all response systems except for respiration rate and salivary cortisol. Although high-anxious subjects did not differ from controls in their average responses to the negative film stimuli, there is a tendency of a greater coherence of emotional response components in generalized anxiety subjects. However, spontaneous facial expressions to positive and negative film stimuli were associated with augmented electrodermal activity within both groups. Results are interpreted in light of directional response fractionation, dimensional approaches of emotion, and the facial feedback literature.     

A sex difference in features that elicit genital response

Previous research suggests that women's genital arousal is an automatic response to sexual stimuli, whereas men's genital arousal is dependent upon stimulus features specific to their sexual interests. In this study, we tested the hypothesis that a nonhuman sexual stimulus would elicit a genital response in women but not in men. Eighteen heterosexual women and 18 heterosexual men viewed seven sexual film stimuli, six human films and one nonhuman primate film, while measurements of genital and subjective sexual arousal were recorded. Women showed small increases in genital arousal to the nonhuman stimulus and large increases in genital arousal to both human male and female stimuli. Men did not show any genital arousal to the nonhuman stimulus and demonstrated a category-specific pattern of arousal to the human stimuli that corresponded to their stated sexual orientation. These results suggest that stimulus features necessary to evoke genital arousal are much less specific in women than in men.     

Modulation of the acoustic startle response by film-induced fear and sexual arousal

The response matching model of Lang, Bradley, and Cuthbert (1992) predicts startle reflex facilitation during negative relative to positive emotional states. Using slide and imagery paradigms, larger eyeblink responses to startle probes for unpleasant than for pleasant conditions have consistently been reported. The present study extended the previously observed relationship between valence and startle to more complex stimuli, namely 1-min film fragments. Thirty-three subjects viewed a sequences of 27 film fragments with neutral, negative (fearful), and positive (sexual) contents, presented in one of three mixed orders. Blink magnitude to brief bursts of white noise was larger during fearful fragments than during sexual fragments. Blink magnitudes habituated across successive film fragments, but the positive-negative difference remained stable within film fragments and during the entire length of the videotape (approximately 40 min).     

Shock Threat and Sexual Arousal: The Role of Selective Attention, Thought Content, and Affective States

In an attempt to detail cognitive processes during anxiety and sexual arousal, 16 heterosexual males were presented with brief erotic audiotapes simultaneous with four levels of shock threat (no shock, half tolerance, tolerance, and twice tolerance threat). Subjects were instructed to pay close attention to the audiotapes, following which a sentence recognition task was administered to assess stimulus-focused attention. Additionally at these times, they were given a thought-listing task and completed a series of affect ratings. Tumescence and subjective arousal were monitored continuously during the erotic stimuli. Results revealed that tolerance shock threat decreased tumescence (p<.05). In contrast, recognition memory was greatest during tolerance shock threat and diminished during twice tolerance shock threat, which also produced increased reports of emotional stales. Issues regarding the relation between cognition and sexual arousal are discussed, including implications for understanding sexual dysfunction.     

Emotions and stress increase respiratory resistance in asthma

OBJECTIVES: Clinical reports suggest that various emotions and types of stress can precipitate asthmatic symptoms, but there is little experimental evidence to substantiate this claim. We studied the impact of different emotional states and stress on respiratory resistance in asthmatic and nonasthmatic individuals. METHODS: Participants (24 asthmatic and 24 nonasthmatic patients) viewed short film sequences selected to induce anxiety, anger, depression, elation, happiness, contentment, or a neutral affective state and completed two stressful tasks, mental arithmetic to induce active coping efforts and viewing of medical slides to induce passive coping efforts. Oscillatory resistance, heart rate, blood pressure, baroreflex sensitivity, skin conductance level, respiration rate and volume, and self-reported affective state were measured throughout the session. RESULTS: Uniform increases in oscillatory resistance were found in all emotional states compared with the neutral state and during mental arithmetic in both groups. Asthmatic patients showed stronger reactions to the medical slides than healthy control subjects, with significant increases in oscillatory resistance, blood pressure, skin conductance level, and minute volume, as well as higher levels of self-reported depression, arousal, and shortness of breath. Changes in oscillatory resistance were inconsistently correlated with other physiological indices. CONCLUSIONS: Various emotional states and stress increase oscillatory resistance largely independently of concurrent increases in autonomic or ventilatory activity. The particular sensitivity of asthmatics to passive coping demand requires additional research.     

Affective modulation of the startle response in depression: influence of the severity of depression, anhedonia, and anxiety

BACKGROUND: The amplitude of the startle reflex response is known to be influenced by the concomitant presentation of affect-toned material--if it is positive affect-toned, the reflex is inhibited, and if it is negative affect-toned, the reflex is augmented. Abundant evidence demonstrates the utility of the affect-startle paradigm as a significant tool for measuring both positive and negative emotions. We applied this paradigm to study emotional reactivity in depression, particularly in relation to symptoms of depression, anhedonia, and anxiety. METHODS: Depressed patients (22) and controls (22) were shown a series of film clips, consisting of two clips with positive valence, two with negative valence, and two with relatively neutral valence. The startle response was measured in reaction to the acoustic startle-eliciting stimuli presented three times binaurally during each clip. RESULTS: Highly depressed and anhedonic patients, relative to controls, showed a reduced mood (self-ratings) and a lack of startle modulation in response to affective film clips whereas patients relatively low on depression/anhedonia displayed a reduced mood only with pleasant clips and a normal pattern of affective startle modulation. Anhedonia and depression were highly positively correlated but neither correlated with anxiety. Anxious patients displayed larger reflexes across all clips and showed a reduced mood modulation with pleasant, but not unpleasant, clips. LIMITATIONS: The large majority of patients was medicated with antidepressants which may have influenced the results. CONCLUSIONS. Reactivity to pleasant stimuli is diminished in patients suffering from low levels of depression and/or anhedonia, but reactivity even to unpleasant stimuli seems compromised at high levels of depression and/or anhedonia. Anxiety is associated with hyperstartle responding.