The effect of odors on human newborn infants under stress

Five-day-old human infants' responses to heelstick stress were assessed with behavioral and physiological indices. The subjects were divided randomly into three groups: the LAV group, who were presented with artificial odor of lavender during the heelstick; the MILK group, who were presented with artificial odor of milk during the heelstick; and the CONT group, who were presented with no special odors. The CONT group showed more adrenocortisol release in saliva than the other groups, but there were no differences between the two odors.     

Olfactory categorization: A developmental study

This study examined the ability of children to classify fruit and flower odors. We asked four groups of children (4-11years of age) and a group of adults to identify, categorize, and evaluate the edibility, liking, and typicality of 12 fruit and flower odors. Results showed an increase in interindividual agreement with age for the taxonomic (fruit/flower) and function-based (edible/nonedible) categories but not for the hedonic component. So, it seems that this hedonic component is not the explicit basis for this increase in interindividual agreement when categorizing an odor as a fruit/flower odor or as being edible or nonedible. An age-related trend was also observed on the typicality scores: The youngest group of children did not show a typicality gradient, but all of the other groups did. Blackcurrant and lemon were rated as the most typical fruit odors, whereas raspberry and peach were rated as the least typical. For flower odorants, results were not as clear, yet it seems that for all groups lavender was considered as quite typical.     

Scent and mood state following an anxiety-provoking task

The purpose of this study was to assess the effects of water, lavender, or rosemary scent on physiology and mood state following an anxiety-provoking task. The nonsmoking participants, ages 18-30 years, included 42 women and 31 men who reported demographic information and measures of external temperature and heart rate were taken prior to introduction of an anxiety-eliciting task and exposure to lavender, rosemary, or water scents. Following the task, participants completed the Profile of Mood States to assess mood, and temperature and heart rate were reassessed. Participants rated the pleasantness of the scent received. When pleasantness ratings of scent were covaried, physiological changes in temperature and heart rate did not differ based on scent exposure, but mood ratings differed by scent condition. Participants in the rosemary condition scored higher on measures of tension-anxiety and confusion-bewilderment relative to the lavender and control conditions. The lavender and control conditions showed higher mean vigor-activity ratings relative to the rosemary group, while both rosemary and lavender scents were associated with lower mean ratings on the fatigue-inertia subscale, relative to the control group. These results suggest that, when individual perception of scent pleasantness is controlled, scent has the potential to moderate different aspects of mood following an anxiety-provoking task.     

Preliminary evidence that acute and chronic daily psychological stress affect sexual arousal in sexually functional women

It is assumed that psychological stress may inhibit sexual arousal in women. Research on the effect of (acute and chronic) psychological stressors on genital and subjective sexual arousal, however, is scarce. To investigate whether psychological stressors indeed inhibit sexual responding, sexually functional women were randomly assigned to an experimental condition (n=30) in which acute psychological stress was induced by a frustrating computer task or a control condition (n=29). After the acute psychological stress or control induction women were exposed to an erotic stimulus. Genital sexual arousal was assessed using vaginal photoplethysmography. Self-report ratings of subjective sexual arousal were collected after the erotic stimulus. Furthermore, women were post hoc divided into a 'low' and a 'high' chronic stress group, based on their pre-assessment scores on a chronic daily stress questionnaire. As predicted, it was found that women in the acute stress condition responded with lower levels of genital and subjective sexual arousal to an erotic stimulus than women in the control condition. In addition, women with high levels of chronic stress responded with lower levels of genital sexual arousal to an erotic stimulus than women with low levels of chronic stress. Chronic stress did not affect the level of subjective sexual arousal.     

Recognition of conspecific odors by laboratory rats (Rattus norvegicus) does not show context specificity

This experiment investigated how contextual cues affect recognition of conspecific odors in laboratory rats (Rattus norvegicus). Rats received 5 encounters with the same odor in the same context. For the 6th test encounter, all rats received a simultaneous presentation of the original odor and a novel odor. The authors tested 1 group of rats (context same) in the same context as before. For the remaining 2 groups, the test encounter was in a different context that 1 group (context different) had experienced but that 1 group (context novel) had not. A significant preference to investigate the novel odor by context-same and context-different rats, but not by context-novel rats, suggests that odor recognition can occur following transfer to a different, but familiar, test context, indicating a lack of context specificity.     

Augmentation, not blocking, in an A+/AX+ flavor-conditioning procedure

An A+/AX+ Pavlovian conditioning design typically produces weakened or blocked conditioning to stimulus X. Two experiments were conducted in which rats first received an odor (A+) paired with an emetic US, and then received odor and taste (AX+) paired with the US. In both experiments, the preconditioned odorfacilitated conditioning to the taste. In Experiment 1, a group that received two odor-illness pairings in A+ conditioning had a stronger taste aversion than a group that only had a single odor-illness pairing. Experiment 2 demonstrated that the strengthened taste aversion in the A+/AX+ condition was not due to stimulus generalization. The results represent a unique outcome in the flavor-aversion literature that is similar to potentiation. We propose that this facilitated conditioning to X in the A+/AX+ design be termedaugmentation.     

Effectiveness of debriefing after a stress-producing deception

This experiment was carried out to determine if after deceiving Ss an E had sufficient credibility to effectively debrief the Ss. Ss in two stress groups were given false information indicating that when a signal light came on they would receive painful electric shocks. Ss in a no-stress group were not told about shocks. After being given the threatening instructions, Ss in one of the stress groups were debriefed concerning the deception (but the “shock electrodes” were not removed) while Ss in the other group were not debriefed. After this the signal light came on for all groups. Arousal was measured by pulse rates and self-reports. The results revealed that (a) the instructions about electric shocks increased the arousal levels of the two stress groups relative to the no-stress group, thus indicating that the deception was effective, and (b) after the signal light came on the stress group which had not been debriefed continued to show a high degree of arousal while the stress group which had been debriefed showed a reduction of arousal to the same low level of arousal as the no-stress group, thus indicating that the process of debriefing had been effective.     

Effects of Environmental Odor and Coping Style on Negative Affect,Anger, Arousal,and Escape1

Trait coping, state anger, perceived arousal, blood pressure, negative affect, and escape behavior were measured in a sample of 240 undergraduate males and females exposed to 1 of 4 foul-odor conditions or to a no-odor condition. Consistent with Baron and Bell's (1976) negative-affect-escape model, it was hypothesized that people exposed to noxious odors would experience increased negative affect and heightened motivation to escape the situation. Results showed that negative affect and motivation to escape, but not anger or arousal, increased significantly as odor became more noxious. In addition, anger and motivation to escape significantly predicted negative affect. Variances in anger and perceived arousal, but not discomfort and escape, were accounted for mainly by trait coping styles and gender differences. Variances in discomfort and escape were accounted for mainly by odor alone.     

Imagery and olfactory stimulation

The purpose of the present study was to investigate a possible odor-emotion interaction by determining whether humans could differentially detect other humans' odor collected under varying emotional conditions. Odorants were collected from the axillary apocrine glands of four female donors, each of whom underwent different imagery induction procedures of anxiety, relaxation, and sexual arousal. The odorants were chemically preserved and later evaluated by 16 naive white male judges as to the presence of discriminatory odor cues. Judges' imagery was differentially related to the anxiety imagery-produced odorants but only for those produced by the most imaginative donors. The relaxation odorants of all donors were correlated. The judges were unable to detect the sexual imagery arousal odorants.     

Some properties of the olfactory system of man

Preliminary investigations into the effects of a 12-h diurnal variation suggested there was a 10-fold decrease in odor sensitivity from morning to evening. For a selected group of odorants (methyl, t-butyl, and phenyl isonitrile), the difference between detection and recognition thresholds in general was found to be 10-fold; however, for some Ss the difference was less. When Ss were blindfolded, no changes in odor sensitivity were noted. Similarly, imposing an auditory stress on the test situation did not significantly alter odor sensitivity in either experienced or naive Ss,     

False physiological feedback and persuasion: Effect of fear arousal vs. fear reduction on attitude change

Two experiments tested the hypothesis that increases in false physiological feedback of fear arousal will enhance persuasion and that reduction in the arousal feedback is unnecessary for increased persuasion to occur. Prior research has usually found a positive relation between level of arousal and persuasion, but support for the drive reduction hypothesis is tenuous. However, Harris and Jellison (1971) claimed support for such a hypothesis. They manipulated subjects' fear arousal cognitively via false physiological feedback while the subjects listened to a persuasive communication. The present experiments used a similar procedure in an attempt to test an "arousal only" against an "arousal reduction" hypothesis. Subjects listened to a persuasive speech while receiving false feedback via a meter concerning their fear arousal. In Experiment I half of the subjects received high arousal and half received moderate arousal information. Within each of these conditions half of the subjects had their arousal reduced, and the other half did not. In Experiment II subjects received either low arousal, high arousal, or high then low arousal feedback while listening. The results of the two studies generally provided support for the "arousal only" hypothesis. An interpretation in terms of Bem's attribution theory was tentatively suggested.     

A controlled study of sensation awareness and verbal disclosure for regulation of arousal and anxiety.

Interactions of attention and verbalization were investigated for effects of self-reported arousal and state-anxiety. Levels of verbalization from silence through talking-without-a-listener to disclosure were compared while self-directed attention was manipulated for sensation versus general thoughts and feelings. Following a stimulus, disclosure of sensations was expected to reduce state anxiety and increase energetic arousal significantly more than disclosure of thoughts. Based on a randomly assigned sample of 120 men, a 3 x 2 x 2 multivariate analysis of variance indicated a significant interaction in the predicted directions. A significant interaction was also found for the 3 x 2 interaction for energetic arousal. For state anxiety means were in the predicted direction. Results indicate that verbalization of sensations is more energizing and calming than silence, while for general thought, silence is more energizing and calming than verbalization. The results suggest efficacy in reframing self-talk to quiet awareness and in communicating sensed distinctions as they emerge.     

Can I borrow a feeling? Spillover of negative arousal from inconsistent information during attitude formation diminishes perceptions of well-being

This research examines the extent to which the negative arousal caused by valence inconsistent supraliminal behavioral information and subliminal primes during attitude formation affects people's perceptions of their current well-being. Participants who received inconsistent information about a novel individual during an impression formation task reported more negative arousal, lower self-esteem, greater depression, and greater perceived stress than those in a control condition. Mediational analyses indicated that negative arousal stemming from attitude formation with valence inconsistent information guided participants' responses to well-being measures via misattribution of this arousal. These results cannot be explained by a simple response bias because recall of negative physical symptoms in the past 2 weeks were unaffected by receiving valence inconsistent information. This research suggests that the spillover of negative arousal from attitude formation, when unable to be easily attributed to the attitude object, served as a cue that people utilized when determining how they felt.     

Odour and Proustian memory: reduction of context‐dependent forgetting and multiple forms of memory

In Experiment 1, the reintroduction of the same ambient odour (lemon or lavender) improved performance four weeks later in both free recall and recognition of a word list. This was a cross‐over design that allowed direct comparison between congruent and incongruent odour conditions. A further comparison with an additional group showed that memory was not improved by the presence of a different odour. Experiment 2 investigated the effect of two odour cues (lemon and lavender) in the same cross‐over design using three learning and memory tests: (1) free recall of a word list; (2) problem solving; and (3) spatial learning. While recall of the word list and spatial learning were best when the same odour was present at both learning and test, there was no such context‐dependent effect for the problem‐solving task. However, the presence of the lavender odour at test improved performance in the problem‐solving task, irrespective of the odour present at the first exposure. Thus although lavender had some effect on problem solving, we saw context‐dependent retrieval only in free recall and spatial learning. We discuss the implications of this dissociation. Copyright © 2001 John Wiley & Sons, Ltd.     

Normative Influence Effects on Sexual Arousal to Nonviolent Sexually Explicit Material1

The role of informational social influence in sexual arousal was explored by measuring the effects of normative influence messages on sexual arousal to a nonviolent sexually explicit story in both male and female subjects. The type of message (high versus low arousal), as well as the reference group sex, were varied. The results showed that (a) subjects who received a message that similar others became highly aroused reported a significantly higher level of arousal than subjects who received the opposite message; (b) male subjects reported a significantly higher level of sexual arousal than females; and (c) a normative message from a male reference group had a stronger impact on both male and female subjects than one from the female reference group, indicating that males are perceived as more credible “experts” on matters of sexual responding man females. The study suggests one means by which individuals learn to respond to sexually explicit materials.     

The role of the dorsal and ventral hippocampus in olfactory working memory

Olfactory working memory and pattern separation for odor information was assessed in male rats using a matching-to-sample for odors paradigm. The odor set consisted of a five aliphatic acids with unbranched carbon chains that varied from two- to six-carbons in length. Each trial consisted of a sample phase followed by a choice phase. During the sample phase, rats would receive one of five different odors. Fifteen seconds later during the choice phase one of the previous odors was presented simultaneously side by side with a different odor that was based on the number of aliphatic acids that varied in the carbon chains from two- to six-carbons in length and rats were allowed to choose between the two odors. The rule to be learned in order to receive a food reward was to always choose the odor that occurred during the study phase. Odor separations of 1, 2, 3 or 4 were selected for each choice phase and represented the carbon chain difference between the study phase odor and the test phase odor. Once an animal reached a criterion of 80–90% correct across all temporal separations based on 40 trials, rats received a control, dorsal hippocampal, or ventral hippocampal lesion and were retested on the task. On postoperative trials, only the ventral hippocampal lesion group was impaired relative to both control and dorsal hippocampal groups groups. There were no effects on odor pattern separation. All groups of rats could discriminate between the odors. The data suggest that the ventral hippocampus, but not dorsal hippocampus, supports working memory for odor information.     

Comparison of Cognitive-Behavioral Stress Management Techniques With Adolescent Boys

This study examined the effectiveness of two cognitive-behavioral interventions to help adolescent boys cope with stress and other forms of negative emotional arousal. One group of youths, those receiving cognitive restructuring, learned how to identify and monitor stress-promoting cognitions, restructure these cognitions into more adaptive thoughts, and practice and apply these acquired skills. Another group of youths received anxiety management training, and they were taught to recognize cues that signal the onset of anxiety and to react to these cues using various relaxation skills to reduce the anxiety. The youths who received training were compared with a waiting list control group on measures of anxiety, anger, self-esteem, depression, and reports of anxious self-statements. Both groups that received the intervention showed significant reductions in levels of state and trait anxiety, state anger, anger expression, and depression. These treatment gains were maintained at an 11-week follow-up.     

Effects of lavender aroma on sleep quality in healthy Japanese students

This single-blind randomized study investigated the effectiveness of lavender aroma on quality of sleep in healthy Japanese students. The data of seven participants (2 men, 5 women) in the intervention group and eight participants (3 men, 5 women) in the control group were analyzed (M age = 19.0 yr., SD = 0.9). The total procedure comprised 3 days for pre-intervention assessment, 5 days for the intervention, and 3 days for post-intervention assessment. Lavender exposure was compared with the absence of lavender (control). Information regarding the relaxing effect of aromas was provided to examine expectancy effects. Results showed that lavender aroma improved sleepiness at awakening after the intervention. Sex differences and daily variation in quality of sleep during the intervention period were not observed. The findings suggest that nighttime exposure to lavender aroma relieves sleepiness at awakening.     

Effects of Rumination and Worry on Sleep

Recent research suggests that the stress-sleep relationship is mediated by pre-sleep arousal (PSA) and that cognitive arousal has a stronger mediating effect than somatic arousal; however, this has not been directly tested. Using multilevel moderated mediation, we compared the effects of cognitive arousal and somatic arousal within the stress-sleep relationship. We also assessed whether two forms of repetitive negative thought—rumination and worry—are similarly involved in the stress-sleep relationship. Data was collected from 178 participants across the United States via an online platform. Participants completed baseline self-report surveys examining rumination tendencies and worry tendencies. Over the course of 2 weeks, participants completed daily questionnaires assessing daily stress, PSA, and sleep quality. Results indicated that indirect effects from stress to sleep quality via PSA were statistically significant at low and high levels of rumination and worry, and people at high levels of rumination and worry had stronger relationships between stress and PSA. Across all models, cognitive arousal consistently accounted for more of the variance in the stress-sleep relationship as compared to somatic arousal. Implications for the cognitive behavioral treatment of insomnia are discussed.