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.

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.

Assessing functional impulsivity using functional near-infrared spectroscopy.

Introduction: In neuromarketing, a recently developing, inter-disciplinary field combining neuroscience and marketing, neurophysiological responses have been applied to understand consumers' behaviors. While many studies have focused on explicit attitudes, few have targeted implicit aspects. To explore the possibility of measuring implicit desire for a product, we focused on functional impulsivity related to obtaining a product as a reward and devised a product-rewarded traffic light task (PRTLT). The PRTLT requires participants to take risks under time pressure in order for them to maximize rewards in the form of commercial products, with the brand of products being an independent variable. Thus, we explored the feasibility of applying a PRTLT in a neuromarketing context to implicitly differentiate between the perceived value of products and supported our data with neurophysiological evidence obtained using fNIRS to concurrently monitor cortical activation. Methods: Thirty healthy students were asked to perform the PRTLT. We compared participants' functional impulsivity toward two different chocolate products that had obviously different values. Along with their behavioral responses, participants' cerebral hemodynamic responses during the PRTLT were measured using fNIRS covering the lateral prefrontal cortices and the neighboring regions. We conducted adaptive general linear model (GLM) analysis for hemodynamic responses. First, we identified the regions involved in the PRTLT. Second, we compared activation patterns between expensive and inexpensive conditions. Results: Behavioral analysis confirmed that the expensive condition trended toward producing a higher PRTLT score than did the inexpensive condition. fNIRS neuroimaging analysis showed task-derived activation in the bilateral dorsolateral prefrontal cortex (DLPFC) and frontopolar cortex (FPC). Moreover, we found significant differences between expensive and inexpensive conditions in the cortical activations in the FPC and the left-DLPFC. Conclusion: These results imply that the two products evoked different functional impulsivity, and the hemodynamic responses reflect that. Thus, we concluded that it is possible to observe differences in demand for products using a PRTLT that evokes functional impulsivity. The current study presents a new possibility in neuromarketing research of observing differences between consumers' covert attitudes toward commercially available products, possibly providing a neural basis related to hidden needs for some products.

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).

Mask wearing increases eye involvement during smiling: a facial EMG study.

The use of face masks has become ubiquitous. Although mask wearing is a convenient way to reduce the spread of disease, it is important to know how the mask affects our communication via facial expression. For example, when we are wearing the mask and meet a friend, are our facial expressions different compared to when we are not? We investigated the effect of face mask wearing on facial expression, including the area around the eyes. We measured surface electromyography from zygomaticus major, orbicularis oculi, and depressor anguli oris muscles, when people smiled and talked with or without a mask. Only the actions of the orbicularis oculi were facilitated by wearing the mask. We thus concluded that mask wearing may increase the recruitment of the eyes during smiling. In other words, we can express joy and happiness even when wearing a face mask.

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.

Dissociating the functions of superior and inferior parts of the left ventral occipito-temporal cortex during visual word and object processing.

During word and object recognition, extensive activation has consistently been observed in the left ventral occipito-temporal cortex (vOT), focused around the occipito-temporal sulcus (OTs). Previous studies have shown that there is a hierarchy of responses from posterior to anterior vOT regions (along the y-axis) that corresponds with increasing levels of recognition - from perceptual to semantic processing, respectively. In contrast, the functional differences between superior and inferior vOT responses (i.e. along the z-axis) have not yet been elucidated. To investigate, we conducted an extensive review of the literature and found that peak activation for reading varies by more than 1 cm in the z-axis. In addition, we investigated functional differences between superior and inferior parts of left vOT by analysing functional MRI data from 58 neurologically normal skilled readers performing 8 different visual processing tasks. We found that group activation in superior vOT was significantly more sensitive than inferior vOT to the type of task, with more superior vOT activation when participants were matching visual stimuli for their semantic or perceptual content than producing speech to the same stimuli. This functional difference along the z-axis was compared to existing boundaries between cytoarchitectonic areas around the OTs. In addition, using dynamic causal modelling, we show that connectivity from superior vOT to anterior vOT increased with semantic content during matching tasks but not during speaking tasks whereas connectivity from inferior vOT to anterior vOT was sensitive to semantic content for matching and speaking tasks. The finding of a functional dissociation between superior and inferior parts of vOT has implications for predicting deficits and response to rehabilitation for patients with partial damage to vOT following stroke or neurosurgery.

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.

Inter- and intrahemispheric connectivity differences when reading Japanese Kanji and Hiragana.

Unlike most languages that are written using a single script, Japanese uses multiple scripts including morphographic Kanji and syllabographic Hiragana and Katakana. Here, we used functional magnetic resonance imaging with dynamic causal modeling to investigate competing theories regarding the neural processing of Kanji and Hiragana during a visual lexical decision task. First, a bilateral model investigated interhemispheric connectivity between ventral occipito-temporal (vOT) cortex and Broca's area ("pars opercularis"). We found that Kanji significantly increased the connection strength from right-to-left vOT. This is interpreted in terms of increased right vOT activity for visually complex Kanji being integrated into the left (i.e. language dominant) hemisphere. Secondly, we used a unilateral left hemisphere model to test whether Kanji and Hiragana rely preferentially on ventral and dorsal paths, respectively, that is, they have different intrahemispheric functional connectivity profiles. Consistent with this hypothesis, we found that Kanji increased connectivity within the ventral path (V1 ↔ vOT ↔ Broca's area), and that Hiragana increased connectivity within the dorsal path (V1 ↔ supramarginal gyrus ↔ Broca's area). Overall, the results illustrate how the differential processing demands of Kanji and Hiragana influence both inter- and intrahemispheric interactions.

Auditory-motor interactions for the production of native and non-native speech.

During speech production, auditory processing of self-generated speech is used to adjust subsequent articulations. The current study investigated how the proposed auditory-motor interactions are manifest at the neural level in native and non-native speakers of English who were overtly naming pictures of objects and reading their written names. Data were acquired with functional magnetic resonance imaging and analyzed with dynamic causal modeling. We found that (1) higher activity in articulatory regions caused activity in auditory regions to decrease (i.e., auditory suppression), and (2) higher activity in auditory regions caused activity in articulatory regions to increase (i.e., auditory feedback). In addition, we were able to demonstrate that (3) speaking in a non-native language involves more auditory feedback and less auditory suppression than speaking in a native language. The difference between native and non-native speakers was further supported by finding that, within non-native speakers, there was less auditory feedback for those with better verbal fluency. Consequently, the networks of more fluent non-native speakers looked more like those of native speakers. Together, these findings provide a foundation on which to explore auditory-motor interactions during speech production in other human populations, particularly those with speech difficulties.

Dissociating visual form from lexical frequency using Japanese.

In Japanese, the same word can be written in either morphographic Kanji or syllabographic Hiragana and this provides a unique opportunity to disentangle a word's lexical frequency from the frequency of its visual form - an important distinction for understanding the neural information processing in regions engaged by reading. Behaviorally, participants responded more quickly to high than low frequency words and to visually familiar relative to less familiar words, independent of script. Critically, the imaging results showed that visual familiarity, as opposed to lexical frequency, had a strong effect on activation in ventral occipito-temporal cortex. Activation here was also greater for Kanji than Hiragana words and this was not due to their inherent differences in visual complexity. These findings can be understood within a predictive coding framework in which vOT receives bottom-up information encoding complex visual forms and top-down predictions from regions encoding non-visual attributes of the stimulus.

Improving the reliability of functional localizers.

A critical assumption underlying the practice of functional localization is that the voxels identified by functional localization are essentially the same as those activated in the main experiment for a particular anatomical area. Violations of this assumption bias the resulting analyses and can dramatically increase the likelihood of both Type I and Type II errors. Here we investigated how the amount of data affects the reliability of a set of common functionally-defined regions-of-interest (fROIs). Four participants were scanned ten times each to functionally localize extrastriate regions sensitive to visually presented words, objects and faces. A within-subject random-effects analysis was used as the "gold standard" for identifying the fROIs and the results were compared to within-subject, fixed-effect analyses typically used for functional localization. By varying the quantity of data included in the analyses, we empirically assessed the amount needed to ensure reliable identification of the fROIs. The results demonstrated that the most consistent fROIs were based on either stringent statistical thresholding (Z>5.0) of large quantities of data or on lenient thresholding (Z>2.3) of a modest amount of data, with both methods yielding 70-80% overlap between the functional localization results and the "gold standard." Stringent statistical thresholds on typical quantities of localizer data led to the poorest reliability (<20% overlap). These findings suggest that the most reliable and cost-efficient method for functional localization involves collecting a relatively small amount of data (~10 min) and using a lenient statistical threshold to identify all voxels in a given region that are sensitive to the process-of-interest.

Top-down modulation of ventral occipito-temporal responses during visual word recognition.

Although interactivity is considered a fundamental principle of cognitive (and computational) models of reading, it has received far less attention in neural models of reading that instead focus on serial stages of feed-forward processing from visual input to orthographic processing to accessing the corresponding phonological and semantic information. In particular, the left ventral occipito-temporal (vOT) cortex is proposed to be the first stage where visual word recognition occurs prior to accessing nonvisual information such as semantics and phonology. We used functional magnetic resonance imaging (fMRI) to investigate whether there is evidence that activation in vOT is influenced top-down by the interaction of visual and nonvisual properties of the stimuli during visual word recognition tasks. Participants performed two different types of lexical decision tasks that focused on either visual or nonvisual properties of the word or word-like stimuli. The design allowed us to investigate how vOT activation during visual word recognition was influenced by a task change to the same stimuli and by a stimulus change during the same task. We found both stimulus- and task-driven modulation of vOT activation that can only be explained by top-down processing of nonvisual aspects of the task and stimuli. Our results are consistent with the hypothesis that vOT acts as an interface linking visual form with nonvisual processing in both bottom up and top down directions. Such interactive processing at the neural level is in agreement with cognitive and computational models of reading but challenges some of the assumptions made by current neuro-anatomical models of reading.

How does learning to read affect speech perception?

Behavioral studies have demonstrated that learning to read and write affects the processing of spoken language. The present study investigates the neural mechanism underlying the emergence of such orthographic effects during speech processing. Transcranial magnetic stimulation (TMS) was used to tease apart two competing hypotheses that consider this orthographic influence to be either a consequence of a change in the nature of the phonological representations during literacy acquisition or a consequence of online coactivation of the orthographic and phonological representations during speech processing. Participants performed an auditory lexical decision task in which the orthographic consistency of spoken words was manipulated and repetitive TMS was used to interfere with either phonological or orthographic processing by stimulating left supramarginal gyrus (SMG) or left ventral occipitotemporal cortex (vOTC), respectively. The advantage for consistently spelled words was removed only when the stimulation was delivered to SMG and not to vOTC, providing strong evidence that this effect arises at a phonological, rather than an orthographic, level. We propose a possible mechanistic explanation for the role of SMG in phonological processing and how this is affected by learning to read.