Right prefrontal activation associated with deviations from expected lipstick texture assessed with functional near-infrared spectroscopy.

Introduction: There is a continuous consumer demand for ever superior cosmetic products. In marketing, various forms of sensory evaluation are used to measure the consumer experience and provide data with which to improve cosmetics. Nonetheless, potential downsides of existing approaches have led to the exploration of the use of neuroimaging methods, such as functional near-infrared spectroscopy (fNIRS), to provide addition information about consumers' experiences with cosmetics. The aim of the present study was to investigate the feasibility of a real-time brain-based product evaluation method which detects the incongruency between a product, in this case lipstick, and a consumer's expectations. Method: Thirty healthy, female, habitual lipstick users were asked to apply six different lipsticks varying in softness and to rate the softness of and their willingness to pay (WTP) for each lipstick. Cerebral hemodynamic responses in frontal areas were measured with fNIRS during lipstick application and analyzed using the general linear model (GLM). Incongruency scores between softness and expectation were calculated in order to understand how far removed each lipstick was from a participant's optimal softness preference. The correlation between brain activation (beta scores) during the application of each lipstick and the respective incongruency scores from each participant were acquired using semi-partial correlation analysis, controlling for the effects of WTP. Results: We revealed a significant intra-subject correlation between incongruency scores and activation in the right inferior frontal gyrus (IFG). This confirms that as the texture incongruency scores increased for the lipstick samples, activation in each individual's right IFG also increased. Conclusion: The correlation observed between incongruency perceived by participants and activation of the right IFG not only suggests that the right IFG may play an important role in detecting incongruity when there is a discrepancy between the perceived texture and the consumer's expectations but also that measuring activity in the IFG may provide a new objective measurement of the consumer experience, thus contributing to the development of superior cosmetics.

Relationships between subjective experience, electroencephalogram, and heart rate variability during a series of cosmetic behavior.

Introduction: Cosmetic behavior is an important daily activity, especially for women, because it increases visual attractiveness, self-confidence, and positive emotions. However, it is unknown whether a relationship exists between physiological measures and subjective experiences during the series of cosmetic behaviors. Methods: Electroencephalograms (EEG) and electrocardiograms (ECG) from thirty female participants who were asked to look in a mirror after applying skincare, as well as base, eye, cheek, and lip makeup were recorded. The price range of cosmetic products was also considered. Subjective evaluations of the skin surface, emotions, and self-confidence were equally measured after looking in the mirror at each step of the cosmetic behavior. Linear mixed models were fitted to examine whether the subjective experience could be explained by the variety of cosmetic products and/or physiological responses. Results: The subjective evaluation was summarized into the following three factors using a factor analysis: self-confidence, hedonic perception, and negative emotion. Each theta-band (4-6 Hz) power, alpha-band (8-13 Hz) power of the EEG, and heart rate variability measures were subjected to a principal component analysis separately. The linear mixed models indicated that the variation in the self-confidence score and the negative emotion score was explained only by the steps of cosmetic behaviors, that is, self-confidence increased while negative emotions decreased as the steps of cosmetic behaviors proceeded. On the other hand, the hedonic perception score was explained by the interaction of the steps of cosmetic behaviors and price, indicating that positive tactile perception and positive emotion were higher when luxury cosmetic products were applied than when affordable products were applied. Furthermore, the model indicated that the hedonic perception score was positively associated with the alpha-band power over occipital sites whereas sympathetic nervous system activity was negatively associated with the alpha-band power over lateral central sites. Discussion: These results suggest that positive perceptual and emotional experiences are associated with greater attention to somatosensory information than to visual information and sympathetic autonomic nervous system activities. The current results also emphasize the possibility of using physiological measurements as objective measures of cosmetic behavior.

Investigating the human chemical communication of positive emotions using a virtual reality-based mood induction.

Humans can communicate their emotions to others via volatile emissions from their bodies. Although there is now solid evidence for human chemical communication of fear, stress and anxiety, investigations of positive emotions remain scarce. In a recent study, we found that women's heart rate and performance in creativity tasks were modulated by body odors of men sampled while they were in a positive vs. neutral mood. However, inducing positive emotions in laboratory settings remains challenging. Therefore, an important step to further investigate the human chemical communication of positive emotions is to develop new methods to induce positive moods. Here, we present a new mood induction procedure (MIP) based on virtual reality (VR), that we assumed to be more powerful than videos (used in our previous study) to induce positive emotions. We hypothesized that, consequently, given the more intense emotions created, this VR-based MIP would induce larger differences between the receivers' responses to the positive body odor versus a neutral control body odor, than the Video-based MIP. The results confirmed the higher efficacy of VR to induce positive emotions compared with videos. More specifically, VR had more repeatable effects between individuals. Although positive body odors had similar effects to those found in the previous video study, especially faster problem solving, these effects did not reach statistical significance. These outcomes are discussed as a function of the specificities of VR and of other methodological parameters, that may have prevented the observation of such subtle effects and that should be understood more in-depth for future studies on human chemical communication.

And I'm feeling good: effect of emotional sweat and perfume on others' physiology, verbal responses, and creativity.

Emotions can be communicated in social contexts through chemosignals contained in human body odors. The transmission of positive emotions via these signals has received little interest in past research focused mainly on negative emotional transmission. Furthermore, how the use of perfumed products might modulate this transmission remains poorly understood. To investigate human positive chemical communication, we explored the autonomic, verbal, and behavioral responses of receivers exposed to body odors of donors having undergone a within-subject positive or neutral mood induction procedure. These responses were compared with those obtained after exposure to the same body odors with added fragrance. Our findings suggest that positive emotions can be transmitted through body odor. They not only induced modifications at the physiological (heart rate) and verbal levels (perceived intensity and familiarity) but also at the behavioral level, with an improved performance on creativity tasks. Perfume did not modulate the physiological effects and had a synergistic effect on the positive body odor ratings (increased perceived differences between the neutral and positive body odor).

Human brain activity reflecting facial attractiveness from skin reflection.

Facial attraction has a great influence on our daily social interactions. Previous studies have mainly focused on the attraction from facial shape and expression. We recently found that faces with radiant skin appear to be more attractive than those with oily-shiny or matte skin. In the present study, we conducted functional magnetic resonance imaging (fMRI) and psychological experiments to determine the human brain activity that reflects facial attractiveness modulated by these skin reflection types. In the fMRI experiment, female subjects were shown successive images of unfamiliar female faces with matte, oily-shiny, or radiant skin. The subjects compared each face with the immediately preceding face in terms of attractiveness, age, and skin reflection, all based on the skin. The medial part of the orbitofrontal cortex (mOFC) was significantly more active when comparing attractiveness than when comparing skin reflection, suggesting that the mOFC is involved in processing facial attractiveness from skin reflection. In the psychological experiment, attractiveness rating was highest for radiant skin, followed by oily-shiny, and then matte skin. Comparison of the results of these experiments showed that mOFC activation level increased with attractiveness rating. These results suggest that the activation level of the mOFC reflects facial attractiveness from skin reflection.

Facial radiance influences facial attractiveness and affective impressions of faces.

OBJECTIVE: Facial attractiveness has been reported to be influenced by visual features such as facial shape and the colour and texture of the skin. However, no empirical studies have examined the effects of facial skin radiance on facial attractiveness. The present study investigated whether types of skin reflection (i.e. radiant, oily and shiny, and matte) and the position of the reflection on the face influence facial attractiveness and other affective impressions. METHODS: A total of 160 female participants (1) estimated the ages and (2) evaluated attractiveness and other impressions of unfamiliar female faces in a total of seven skin reflection conditions. These conditions incorporated three types of reflection (i.e. radiant, oily and shiny, and matte) and three positions of the reflection on the face (i.e. entire facial skin, only cheeks, and only T-zone). RESULTS: The facial images of radiance on entire faces were rated as appearing younger than the facial images of oily shine on entire faces and the matte faces. Attractiveness ratings and other positive impressions increased in the order of the matte (ranked lowest), the oily shine on entire face, and the radiance on entire face (ranked highest) conditions. The reflection position also influenced facial attractiveness: attractiveness ratings and other positive impressions were higher in the radiance on entire face condition than in the radiant cheeks and the radiant T-zone conditions. Interestingly, the radiant cheek faces were rated more radiant and healthier but less feminine and less bright than the radiant T-zone faces. CONCLUSION: These results suggest that facial radiance enhances facial attractiveness and conveys a wide variety of positive impressions on the observer. The magnitude of the effects of cheek radiance and T-zone radiance differs across various affective impressions. Nevertheless, the results demonstrate that cheek and the T-zone radiance both contribute to higher attractiveness and other positive impressions of the radiance on entire faces. We believe that our findings can contribute as a guide to the enhancement of positive facial impressions by means of skin radiance, thereby leading to a better understanding of the value of skincare and base makeup.

OBJECTIF: Selon certaines études, l'attractivité du visage viendrait de caractéristiques visuelles telles que la forme du visage ainsi que la couleur et la texture de la peau. Cependant, aucune étude empirique n'a examiné les effets de l'éclat de la peau sur l'attractivité du visage. La présente étude s'est intéressée aux divers types de reflets de la peau (par exemple une peau lumineuse, une peau grasse et luisante ou une peau mate) et à leur position sur le visage, et a cherché à savoir s'ils influençaient l'attractivité du visage et d'autres impressions d'ordre affectif. MÉTHODES: Au total, 160 participantes 1) ont estimé l'âge et 2) ont évalué l'attractivité et d'autres impressions de visages féminins inconnus sur sept types de reflets de la peau au total. Ces états comprenaient trois types de reflets (lumineux, gras et mat) et trois positions des reflets sur le visage (toute la peau du visage, joues uniquement et partie yeux-nez [« zone T ¼] uniquement). RÉSULTATS: Les photos de visages caractérisées par un éclat sur tout le visage ont été considérées comme étant plus jeunes que celles dont la peau était grasse-luisante sur l'ensemble du visage et que les visages à peau mate. Les notes attribuées pour l'attractivité et les autres impressions positives augmentent dans l'ordre suivant : peau mate (note la plus basse), peau grasse-luisante sur tout le visage et luminosité sur tout le visage (note la plus haute). La position du reflet a elle aussi joué un rôle sur les notes attribuées à l'attractivité des visages, et les autres impressions positives ont obtenu des scores plus élevés pour une luminosité de tout le visage que pour des joues lumineuses et une zone T lumineuse. Il est intéressant de noter que les visages aux joues lumineuses ont été jugés plus lumineux et plus sains, mais moins féminins et moins éclatants que les visages présentant une zone T lumineuse. CONCLUSION: Ces résultats suggèrent que l'éclat du visage améliore l'attractivité du visage et communique toutes sortes d'impressions positives à l'observateur. L'ampleur des effets de l'éclat sur les joues et sur la zone T diffère selon les différentes impressions d'ordre affectif. Néanmoins, les résultats démontrent que la luminosité des joues et de la zone T contribue à rendre le visage plus séduisant ainsi qu'à d'autres impressions positives suscitées par la luminosité de l'ensemble du visage. Nous sommes convaincus que nos résultats peuvent servir à guider la façon de renforcer l'impression positive produite par un visage en faisant ressortir la luminosité de la peau, et amener ainsi à mieux comprendre la valeur des soins de la peau et des bases de maquillage.

A Willingness-to-Pay Associated Right Prefrontal Activation During a Single, Real Use of Lipsticks as Assessed Using Functional Near-Infrared Spectroscopy.

Understanding consumer preferences and behavior is a major goal of consumer-oriented companies. The application of neuroscience to this goal is a promising avenue for companies. Previously, we observed a positive correlation during actual cosmetic use between the right dorsolateral prefrontal cortex (dlPFC) activity, measured by functional near-infrared spectroscopy (fNIRS), and the associated willingness-to-pay (WTP) values. However, we were unable to find any consistent group differences in the right dlPFC between different powdery foundations. Thus, the main objective of this study was to replicate the previous study and in addition, we aimed to refine the method of the previous study to increase the chance that a difference in valuation between different products can be detected. Twenty-five frequent lipstick using females were asked to apply six different lipsticks to their lips and to record how much they were willing to pay. To maximize the variation of the subjective experience of the products and the associated brain activity, the most preferred color lipstick and a less preferred color lipstick were chosen for each participant, and each color of lipstick had three different textures (Lo, Mid, and Hi). The time series was analyzed with the general linear model (GLM) and the correlation between the right dlPFC beta scores for the lipsticks and their respective WTP values conducted for each participant. This revealed a significant positive correlation and replicated our previous study. Surprisingly, the lipstick color and the texture manipulations did not result in any consistent differences in WTP and similarly no consistent group differences in brain activations. This study replicates our previous study extending it to a different type of cosmetic. The right dlPFC activity during the use of cosmetics may be a potential brain-based personalization or product selection process biomarker.

Willingness-to-Pay-Associated Right Prefrontal Activation During a Single, Real Use of Cosmetics as Revealed by Functional Near-Infrared Spectroscopy.

Use of applied neuroscience to complement traditional methods of consumer research is increasing. Previously, fMRI has shown that prefrontal activity contains information relating to willingness-to-pay (WTP). The aim of the present study was to determine if functional near infrared spectroscopy (fNIRS) can record WTP-related brain activation in the dorsolateral prefrontal cortex (DLPFC) during a single, real use of cosmetic products. Thirty female participants, were divided into two groups (one low frequency users of foundation and one high frequency users of foundation), asked to apply different foundations to their face and then record how much money they were willing to pay. The oxyhemoglobin time series was analyzed with the GLM and the correlation between the beta scores for the foundations and their respective WTP values conducted for each participant. These subject level correlations were then converted to z scores and averaged for each group. The results revealed a significant mean correlation for the high but not low frequency group. In other words, the brain activity in right hemisphere dorsolateral PFC (RH-DLPFC) during single, real use of foundations correlated with their respective WTP values for the high frequency but not low frequency group. The difference between groups may reflect the importance of learning and automation on activity in RH-DLPFC. Our research provides further evidence supporting the use of fNIRS to complement traditional consumer research in a commercial setting and to extend neuroscience research into more naturalistic environments.

The light-makeup advantage in facial processing: Evidence from event-related potentials.

The effects of makeup on attractiveness have been evaluated using mainly subjective measures. In this study, event-related brain potentials (ERPs) were recorded from a total of 45 Japanese women (n = 23 and n = 22 for Experiment 1 and 2, respectively) to examine the neural processing of faces with no makeup, light makeup, and heavy makeup. To have the participants look at each face carefully, an identity judgement task was used: they were asked to judge whether the two faces presented in succession were of the same person or not. The ERP waveforms in response to the first faces were analyzed. In two experiments with different stimulus probabilities, the amplitudes of N170 and vertex positive potential (VPP) were smaller for faces with light makeup than for faces with heavy makeup or no makeup. The P1 amplitude did not differ between facial types. In a subsequent rating phase, faces with light makeup were rated as more attractive than faces with heavy makeup and no makeup. The results suggest that the processing fluency of faces with light makeup is one of the reasons why light makeup is preferred to heavy makeup and no makeup in daily life.

Faces with Light Makeup Are Better Recognized than Faces with Heavy Makeup.

Many women wear facial makeup to accentuate their appeal and attractiveness. Makeup may vary from natural (light) to glamorous (heavy), depending of the context of interpersonal situations, an emphasis on femininity, and current societal makeup trends. This study examined how light makeup and heavy makeup influenced attractiveness ratings and facial recognition. In a rating task, 38 Japanese women assigned attractiveness ratings to 36 Japanese female faces with no makeup, light makeup, and heavy makeup (12 each). In a subsequent recognition task, the participants were presented with 36 old and 36 new faces. Results indicated that attractiveness was rated highest for the light makeup faces and lowest for the no makeup faces. In contrast, recognition performance was higher for the no makeup and light make up faces than for the heavy makeup faces. Faces with heavy makeup produced a higher rate of false recognition than did other faces, possibly because heavy makeup creates an impression of the style of makeup itself, rather than the individual wearing the makeup. The present study suggests that light makeup is preferable to heavy makeup in that light makeup does not interfere with individual recognition and gives beholders positive impressions.

A near-infrared spectroscopy study of differential brain responses to one or two-handed handing actions: An implication for cultural difference in perceived politeness / Un estudio de espectroscopía casi a infraroja de respuestas cerebrales diferenciadas en acciones de una o dos manos: una implicación para la diferencia cultural en la cortesía percibida

In interpersonal communication, body posture and nonverbal behavior serve as important channels for transmitting social signals and these often vary among cultures. Specific body postures and actions have not only functional, but also affective elements. For example, in Japan, handing an object to another with both hands is considered polite behavior whereas using only one hand is not. In this study, we have examined whether handing with both hands and handing with one hand would produce indications of differential brain activities in the receiver, and whether this activity would differ among people with different cultural backgrounds. Changes in oxy-Hb concentration were measured by 48-channel near infrared spectroscopy (NIRS) from 51 female participants (25 Japanese and 26 non-Japanese). The experimenter handed a bottle to participants using both or one hand. Results showed different amounts of change in oxy-Hb concentrations in the inferior frontal regions, depending on whether one hand or both hands were used. Moreover, the pattern of brain reactions in the inferior frontal regions differed between our Japanese and non-Japanese participants. A discriminant analysis of differences in oxy-Hb values suggested that the degree of oxy-Hb reaction in the right side of inferior frontal regions could predict to which group the participants belonged. These results suggest that different cultural and habitual backgrounds may lead to different NIRS activity while interpreting another's actions, and oxy-Hb IFG concentration may reflect differential interpretations of another's actions.

En la comunicación interpersonal, la postura corporal y el comportamiento no verbal sirven como canales importantes para la transmisión de señales sociales y estas por lo general suelen variar entre culturas. Las posturas corporales específicas y las acciones tienen no sólo elementos funcionales, sino también afectivos. Por ejemplo, en Japón, la entrega de un objeto a otro con las dos manos se considera conducta cortés, mientras que con una sola mano no lo es. En este estudio, hemos examinado si la entrega con las dos manos y la entrega con una mano producen señales de actividad cerebral diferencial en el receptor, y si esta actividad sería diferente entre las personas con diferentes orígenes culturales. Los cambios en la concentración de oxi-Hb fue medida por espectroscopia de infrarrojo cercano de 48 canales (NIRS) de 51 mujeres participantes (25 japonesas y 26 no japonesas). El experimentador le entregó una botella a los participantes utilizando una o ambas manos. Los resultados mostraron diferentes cantidades de cambio en las concentraciones de oxi-Hb en las regiones frontales inferiores, dependiendo de si se utilizaba una o ambas manos. Por otra parte, el patrón de las reacciones cerebrales en las regiones frontales inferiores difiere entre los participantes japoneses y no japoneses. Un análisis discriminante de las diferencias en los valores de oxi-Hb sugirió que el grado de reacción de oxi-Hb en el lado derecho de las regiones frontales inferiores podría predecir a que grupo pertenecían las participantes. Estos resultados sugieren que los distintos orígenes culturales y de hábitos puede dar lugar a actividades diferentes en NIRS, mientras que al interpretar las acciones de los otros, y la concentración de oxi-Hb en IFG puede reflejar interpretaciones diferenciales de las acciones del otro.

Relation between asymmetry of prefrontal cortex activities and the autonomic nervous system during a mental arithmetic task: near infrared spectroscopy study.

The present study evaluated the relationship between asymmetry of the prefrontal cortex activity and the automatic nervous system (ANS) response during a mental arithmetic (MA) task. Employing near infrared spectroscopy, we compared cerebral blood oxygenation changes in the right and left prefrontal cortices during a mental arithmetic task with HR changes. During the MA task, eight subjects (high-HR group) showed large HR increases (14.2 +/- 3.0) while eight subjects (low-HR group) showed small HR increases (3.6 +/- 2.8) (P < 0.00001). In both the high-HR and low-HR groups, near infrared spectroscopy (NIRS) demonstrated increases of oxyhemoglobin and total hemoglobin (=oxyhemoglobin + deoxyhemoglobin) associated with decreases of deoxyhemoglobin in the bilateral prefrontal cortices during MA task. In the high-HR group, the laterality ratio scores, i.e., [(R - L)/(R + L) of oxyhemoglobin and total hemoglobin], showed positive values (0.17 +/- 0.11 and 0.17 +/- 0.17, respectively), while in the low-HR group, the laterality ratio scores showed negative values (-0.28 +/- 0.21 and -0.35 +/- 0.24, respectively). In addition, there were significant positive correlations between HR changes and the laterality ratio scores of oxyhemoglobin (r = +0.87, P < 0.0001) and total hemoglobin (r = +0.85, P < 0.0001). These results indicate that the MA task-induced activity in the right prefrontal cortex was larger than that in the left prefrontal cortex in the subject with high HR increases, suggesting that the right prefrontal cortex activity during the MA task has a greater role in cerebral regulation of HR by virtue of decreasing parasympathetic effects or increasing sympathetic effects.