Arianna Trettel

How to Measure Cerebral Correlates of Emotions in Marketing Relevant Tasks

Nowadays, there is a growing interest in measuring emotions through the estimation of cerebral variables. Several techniques and methods are used and debated in neuroscience. In such a context, the present paper provides examples of time-varying variables related to the estimation of emotional valence, arousal and Approach-Withdrawal behavior in marketing relevant contexts. In particular, we recorded electroencephalographic (EEG), galvanic skin response (GSR) and heart rate (HR) in a group of healthy subjects while they are watching different TV commercials. Specifically, results obtained in the Experiment 1 shows a significant increase of cortical power spectral density across left frontal areas in the alpha band and an enhance of cardiac activity during the observation of TV commercials that have been judged pleasant. In the Experiment 2, frontal EEG asymmetry, GSR and HR measurements are used to draw cognitive and emotional indices in order to track the subject’s internal state frame by frame of the commercial. A specific case study shows how the variations of the defined Approach-Withdrawal and emotional indices can distinguish the reactions of younger adults from the older ones during the observation of a funny spot. This technology could be of help for marketers to overcome some of the drawbacks of the standard marketing tools (e.g., interviews, focus groups) usually adopted during the analysis of the emotional perception of advertisements.

EEG Frontal Asymmetry Related to Pleasantness of Olfactory Stimuli in Young Subjects

It is widely known, in neuroscientific literature, that the brain prefrontal cortex activity asymmetry is closely linked with the pleasantness emotion experienced by the subject during a sensorial stimulation. Thus, from the electroencephalographic (EEG) signal it is possible to estimate the approach/withdrawal index, and this index has been largely investigated and validated in scientific literature, regarding visual and acoustic stimuli. In this work, we present an innovative study aimed to prove, in a systematic way, that such brain AW index is actually correlated with the “pleasant” or “no-pleasant” perception also of olfactory stimuli, conveniently produced by standardised methods in the sensory specific scientific literature. In particular, we recorded the electroencephalographic (EEG) signal from a group, gender balanced, of 24 healthy and no-smokers subjects during the perception of ten different smells, presented by means of the “Screening test-odour identification” set (Sniffin’ sticks, Burghart). The cerebral AW indexes of all the subjects, for each odorous stimulus, were compared with the appreciation numeric score assessed by the subject during the experiment, by performing a statistical correlation test. Findings show that it is possible to evaluate the pleasantness or no-pleasantness of odorous substances by means of the analysis of EEG signals collected during the presentation of such substances, making way for new applications of such measure kind in experimental environments more and more ecological, as the typical ones of the marketing research areas.

Neuroelectrical Indexes for the Study of the Efficacy of TV Advertising Stimuli

In this chapter, we present the findings of an experiment aimed to investigate cognitive and emotional changes of cerebral activity during the observation of TV commercials. In particular, we recorded the electroencephalographic (EEG), galvanic skin response (GSR) and heart rate (HR) from a group of 24 healthy subjects during the observation of a series of TV advertisements. The group was equally divided also by gender (male, female) and age (young, old). Comparisons of cerebral and emotional indices previously defined have been performed to highlight gender differences between TV commercial and scenes of interest of specific commercials. Findings show how EEG methodologies, along with the measurements of autonomic variables, could be used to obtain information not obtainable otherwise with verbal interviews. These cerebral and emotional indexes could help to analyze the perception of TV advertisements according to the consumer’s gender and age.

An electroencephalographic Peak Density Function to detect memorization during the observation of TV commercials

Nowadays, there is a growing interest in measuring the impact of advertisements through the estimation of cerebral reactions. Several techniques and methods are used and discussed in the consumer neuroscience. In such a context, the present paper provides a novel method to estimate the level of memorization occurred in subjects during the observation of TV commercials. In particular, the present work introduce the Peak Density Function (PDF) as an electroencephalographic (EEG) time-varying variable which is correlated with the cerebral events of memorization of TV commercials. The analysis has been performed on the EEG activity recorded on twenty healthy subjects during the exposition to several advertisements. After the EEG recordings, an interview has been performed to obtain the information about the memorized scenes for all the video clips watched by the subjects. Such information has been put in correlation with the occurrence of transient peaks of EEG synchronization in the theta band, by computing the PDF. The present results show that the increase of PDF is positively correlated, scene by scene, (R=0.46, p<;0.01) with the spontaneous recall of subjects. This technology could be of help for marketers to overcome the drawbacks of the standard marketing tools (e.g., interviews, focus groups) when analyzing the impact of advertisements.

Neuroelectric brain imaging during a real visit of a fine arts gallery: a neuroaesthetic study of XVII century Dutch painters

Neuroaesthetic is a scientific discipline founded more than a decade ago and it refers to the study of the neural bases of beauty perception in art. The aim of this paper is to investigate the neuroelectrical correlates of brain activity of the observation of real paintings showed in a national fine arts gallery (Scuderie del Quirinale) in Rome, Italy. In fact, the present study was designed to examine how motivational factors as indexed by EEG asymmetry over the prefrontal cortex (relative activity of the left and right hemispheres) could be related to the experience of viewing a series of figurative paintings. The fine arts gallery was visited by a group of 25 subjects during an exhibition of the XVII century Dutch painters. Results suggested a strict correlation of the estimated EEG asymmetry with the verbal pleasantness scores reported by the subjects (p<;0,05) and an inverse correlation of the perceived pleasantness with the observed paintings surface dimensions (d<;0,002).

A Neuroaesthetic Study of the Cerebral Perception and Appreciation of Paintings by Titian Using EEG and Eyetracker Measurements

The neuroelectrical and the eye-movements activities were collected in a group of 27 healthy subjects during their visit of a fine arts gallery displaying twenty paintings of Titian. Evaluation of the appreciation of the paintings was performed by using the neuroelectrical approach-withdrawal index (AW). AW index was estimated for two groups of ten paintings of Titian: one group was related to religious matter while the second was related to portraits. In addition, it was compared the population AW indexes estimated in the first 10 seconds of the observation across all the selected paintings with the AW index estimated in the last 40 seconds of the observation. The number and the total duration (in seconds) spent on the eye fixations performed by the subjects during the observation of the paintings was also analyzed.

EEG-based Approach-Withdrawal index for the pleasantness evaluation during taste experience in realistic settings

The taste is a vital sense in humans, because of its active role in regulating nutrition or avoiding harmful substances. Several studies showed the important role of the brain Pre-Frontal Cortex in decoding information coming from the gustatory system. It is also widely known, in neuroscientific literature, that the asymmetry of Pre-Frontal Cortex Activity is closely linked to the feeling of pleasantness experienced by the subject during sensorial stimulation. In this regard, from the electroencephalographic (EEG) signal it is possible to estimate the Approach/Withdrawal (AW) index, which has been largely investigated and validated in scientific literature, regarding visual, acoustic and olfactory stimuli.

Transparency and Reliability in Neuromarketing Research

In this chapter, we discuss about the transparency and reliability issues in the practice of the application of neuroscience-based methodologies on relevant marketing stimuli (e.g., neuromarketing). It is hypothesized that one of the reasons of the misperception and overestimation by the public opinion and mass media of the actual capabilities of the neuromarketing to inform marketing researcher is due to the lack of the transparency about the methodologies employed by the neuromarketing companies. In fact, different companies offer services that are based on proprietary computational methods and approaches that are not fully validated or disclosed through scientific publications to the scientific community. This opacity in the methodologies employed by some companies makes it difficult for the scientists to separate supported and unsupported claims of validity of the services offered by those companies. Such confusion is reflected in an often misplaced communication toward the public opinion and the final users of these methodologies about the effective capability of such approach to capture the generation of the decision making of the persons in front of marketing stimuli.

The first impression is what matters: a neuroaesthetic study of the cerebral perception and appreciation of paintings by Titian.

In this paper we measured the neuroelectrical and the eye-movements activities in a group of 27 healthy subjects during their visit of a fine arts gallery in which a series of masterpieces of the Italian painter Tiziano Vecellio (also known as Titian, 1488-1576) were shown. The pictures chosen for the visit were 10 portraits and 10 of religious subjects. Each picture was observed for a minute. A mobile EEG device with an eye-tracker was used for this experiment. Evaluation of the appreciation of the pictures was performed by using the neuroelectrical approach-withdrawal index (AW). High value of AW means high appreciation of the picture. The number of eye fixations performed by the subjects during the observation of the pictures was also analyzed. Results showed that in the examined group the AW index was significant higher during the observation of portraits than during the observation of the religious subjects (as resulted from an ANOVA performed on AW index, with a p<;0,007). Interestingly, the average AW index estimated in the first 20 seconds of the observation of the pictures remains highly correlated with the AW index evaluated for the second part of the data (from 20 s to one minute) for all the 20 pictures examined (r = 0,82, p<;0,0001). In addition, the number of eye fixations performed by the subjects in the first 5 or 10 seconds of observation of the pictures that were most appreciated are significantly higher than the number of eye fixations performed on pictures that subjects did not like (p<;0,048 and p<;0,0018, respectively). Such difference vanishes if the entire period of observation of the pictures of one minute is used (p = 0,54). Taken together, such results seem to suggest that the neuroelectrical correlates of the perception of “good” or “bad” pictures are rapidly formed in our brain, within the first 10-20 seconds from the exposition to the picture.

Methodology of a Typical “Neuromarketing” Experiment

The present Chapter illustrates the scenario of a series of neuromarketing experiments we performed in the last years to investigate the EEG cerebral activations correlated with memorization, attention and emotional processing of individuals while watching TV commercials. A large space to the basics knowledge of the high resolution EEG technology is provided. Specifically, we show how it is possible to enhance the spatial resolution of the EEG by solving the related linear inverse problem in order to obtain an estimation of the cortical sources. In addition, the theory we used to perform the spectral statistical analysis is also presented along with a direct example on fake data.