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brand endorsements: Electrophysiological time course evidence
Neuroscience Letters 712 (2019) 134436
Contents lists available at ScienceDirect
Neuroscience Letters journal homepage: www.elsevier.com/locate/neulet
Research article
How expertise congruency effect matters in celebrity/brand endorsements: Electrophysiological time course evidence
T
⁎
Hao Wang, Zjijie Song , Rui Shi, Yupeng Mei, Chang Liu School of Economics and Management, Yanshan University, No. 438, Heibei Road, Qinhuagndao, 066004, China
A R T I C LE I N FO
A B S T R A C T
Keywords: Celebrity-brand Expertise congruency effect Event-related potentials N2 LPP
Celebrity/brand endorsement is omnipresent and has great influence on consumers. In the current study, the event-related potentials (ERPs) were utilized to explore the neural process underlying how expertise congruency effect matters in ads. Twenty-five participants (two excluded) were recruited to accept or refuse the brands (stimulus 2) endorsed by celebrities (stimulus 1) during a S1–S2 paradigm. Behavioral results indicated significant differences in the acceptance rates and reaction time, while ERPs component provided further insight into the cognitive processing: early conflicted perception and later memory recollection process. The results of ERPs showed that, when the celebrity is an athlete star, presenting a sport brand (AS, expertise congruity) triggered a less negative N2 and a larger LPP component compared to a leisure brand (AL, expertise incongruity) but not different with singer star (SS and SL, expertise neutrality). We suggested the N2 may reflect the conflict process of celebrity-brand, while the LPP may demonstrate the recollection process of expertise association in memory. Such findings implied that a more fluent processing (smaller N2 and larger LPP) and prominent performances could be obtained in an expertise congruity scenario, which deepened our understanding of expertise congruency effect in advertising.
1. Introduction Celebrity/brand endorsements enjoy using celebrities for enhancing marketing communications [1,2]. In fact, celebrity status emerges from a variety of sources such as film acting, music, etc., one major source of fame is athletic prowess. Although athletes have appeared as endorsers for brands including Nike, Coca-Cola, Pizza Hut, etc., the performance of these ads is not necessarily as good as expected. Many suggest that expertise with the product that is related in some way to athletic performance can make for a better fit with the endorsed product. Namely, consumers would naturally see more of a fit between an athlete endorser and a sport brand than between an athlete and a non-sport brand [3,4]. Companies are obsessed with celebrity endorsements, but the associations with celebrity do not automatically benefit the brand [5,6], a deep understanding of the mechanisms of expertise effect remains a significant goal for researches. As the "match-up hypothesis" suggests, the inherent match or consistency between celebrities and brands makes endorsement more effective [7]. Especially, the match should reflect the salient attributes of the brand and the distinctive characteristics of the celebrity [6,8]. Some traditional marketing studies have shown that expertise is widely considered as an important dimension for driving the fit between an ⁎
endorser and a brand [4,6,8]. In advertising, consumers are always exposed to hundreds of short ads in one form or another: from web ads to TV commercials and others information. How they quickly perceiving the expertise of endorsers and the matching-up with brands, involves the effectiveness and acceptance of the brands. However, it is a pity that the expertise congruency effect in celebrity/brand endorsements has nearly been ignored by cognitive neuroscientists. In recent years, neural methods are increasing adopted in advertising. A study using functional magnetic resonance imaging (fMRI) finds an increase in activity in the medial orbitofrontal cortex (mOFC) underlying the processing of celebrity–product pairings [9]. It shows that a single exposure to a combination of expert and product leads to a long-lasting positive effect on memory and attitude towards product, whereas non-expert endorser does not [9,10]. Compared to fMRI, event-related potentials (ERPs) have high time resolution, allowing researchers instantaneously assess the subject's underlying neural activities and determine how early a cognitive process takes place [11,12]. Thus, in the current study, we focus on athlete and singer celebrities (representing different expertise), take celebrities to manipulate the expertise congruency with a particular brand (e.g. sport or leisure brand), utilize ERPs to explore how subjects perceiving the expertise congruency and how it matters in celebrity-brand endorsements.
Corresponding author. E-mail address: [email protected] (Z. Song).
https://doi.org/10.1016/j.neulet.2019.134436 Received 10 May 2019; Received in revised form 7 August 2019; Accepted 14 August 2019 Available online 31 August 2019 0304-3940/ © 2019 Published by Elsevier B.V.
Neuroscience Letters 712 (2019) 134436
H. Wang, et al.
Fig. 1. Experimental procedure: participants were instructed to decide whether to accept the brand endorsed by the presented celebrity.
names). Stimulus 1 was celebrity name selected from one of two expertise backgrounds (6 athlete stars and 6 singer stars).A 5 Likert Scale questionnaire was adopted to investigate their reputation (Mathlete stars = 3.92, Msinger stars = 4.03, t=−1.41, p = 0.188) and popularity (Mathlete stars = 4.09, Msinger stars = 4.13, t=−0.41, p = 0.694). Besides, there was no difference in the familiarity of these stars (Mathlete stars = 3.76, Msinger stars = 3.85, t=−1.02, p = 0.262). Stimulus 2 was brand name selected from one of two categories (10 sport brands and 10 leisure brands). All the brands were chosen from the Well-known Trademark List of the China Trademark Office, which sport brands included Adidas, Anta (famous local clothing brand) and leisure brands included Playboy and Yishion (famous local clothing brand), etc. A pretest questionnaire indicated that a singer’ expertise association with sport and leisure brands is generally neutral, but the association between an athlete and the above brands is quite different. Thus, stimulating pictures are created in different sets: (i) expertise congruity: athlete star endorses sport brand, AS; (ii) expertise neutrality: singer star endorses sport brand, SS; (iii) expertise neutrality: singer star endorses leisure brand, SL; (iv) expertise incongruity: athlete star endorses leisure brand, AL. Each set has 60 pairs consisted of a celebrity and a brand name (limited to no more than four Chinese characters on a gray background).
Previous studies show that ERPs have been defined as different components and widely used to reveal particular cognitive processes [13,14]. Among them, N2 component is sensitive to cognitive conflict, reflecting the mismatch of pair stimulus [15,16]. In a neurological study of celebrity fans, larger N2 is observed in response to the photos of familiar or unfamiliar people rather than celebrity, reflecting the inhibition of action because of fans' anticipation of their favorite celebrity [17]. Besides, researches on brand extension evaluation have shown the higher N2 amplitude evoked in the early process if the extension product name was not related to the brand name in terms of category [18,19]. So, what if subjects encounter a perceptual expertise congruity/incongruity of the endorser and brand in short ads? In current experiment, as the paradigm is adapted from a word-pair paradigm suggested by M Qingguo, et al. [19], we expect N2 can be an index of expertise congruencies. In addition to N2, the LPP, as a slow centro-parietal positive component occurred between 400 and 800 ms, has been reported to be associated with recollection [20], which is accompanied by emotional processing [21,22]. Research finds that the LPP enhancement is elicited for familiar compared with unfamiliar stimuli [23]. In a study, due to the easily active association of the imitated leading brand and its products, a larger LPP is evoked with near copycat branded product than with far copycat branded product [24]. In the same way, in our study we hope when celebrity endorses a brand that closely relevant/irrelevant to his/her expertise, a similar pattern of LPP might be observed in later stage by analogy. Based on the above analyses, we assumed that examining the N2 amplitude could help elucidate whether or how subjects are sensitive to the expertise congruencies, while the LPP amplitude in later process could deeply reveal how the spontaneous retrieval of explicit expertise memories associated with celebrity-brand in ads. This experiment aimed to test the hypothesis and explored the neuronal mechanism of expertise congruency effect, especially the time course of expertise perception between celebrity and brand.
2.3. Procedure Participants sat comfortably in a closed laboratory 70 cm away from a LCD screen. All stimuli pairs (S1-S2) were classified into 4 blocks, each consisted of 60 trials, programmed and presented using E-Prime 2.0 software (Psychology Software Tools, Pittsburgh, PA, USA) in a pseudorandom order with a visual angle of 2.85° × 1.37°. In detail (see Fig. 1), each trial began with a fixation cross against a gray background for 500 ms. After a random blank interval (400–600 ms), S1 (celebrity names) was appeared for 1500 ms, followed by a blank interval for 400–600 ms randomly before S2 (brand names) was presented for 3000 ms. The target stimuli (S2) would disappear until a response, followed by a blank interval for 400–600 ms. Participants were instructed to decide whether to accept the brand endorsed by the presented celebrity in consideration of their expertise associations. Left button means accepted and right button means unaccepted. The response-to-hand assignments were counter balanced across the participants.
2. Methods 2.1. Participants Twenty-five healthy graduates and undergraduates participated in this experiment approved by the Internal Review Board of Cognitive Neuroscience Lab at Yanshan University. All subjects were right-handed and native Chinese speakers, reported normal or corrected-to-normal vision without any history of neurological or mental diseases. Written informed consent was obtained from each subject before the formal experiment. Data of two subjects were excluded for excessive artifacts during EEG recording, resulting in 23 valid subjects (10 male) aged 24.2 (SD = 2.8, range = 22–26) years.
2.4. EEG recording and analysis EEG data was recorded (band pass 0.01–100 Hz, sampling rate 500 Hz) with a Brain actiCHamp amplifier (Brain Products GmbH, Munich, Germany), using an electrode cap with 64 Ag/AgCl electrodes according to the extended international 10–20 system and referenced to linked mastoids. The cephalic location was served as the ground. Horizontal and vertical electro-oculograms were recorded through electrodes placed 10 mm from the lateral canthi of both eyes and above and below the left eye. Impedances were kept below 5 kΩ during the
2.2. Stimulus materials The stimuli consisted of 240 pairs (12 celebrity names × 20 brand 2
Neuroscience Letters 712 (2019) 134436
H. Wang, et al.
3.2. ERPs results
research. BrainVision Analyzer 2.1 was used to process the collected data offline. The average of left and right mastoids was transformed as the new references, and Ocular Correction ICA was used to exclude EOG artifacts followed by 16 Hz (24 dB/octave) digital low pass filter. Trials containing electromyography activity, other artifacts, or peak-to-peak deflection exceeding ± 100 μV were excluded. EEGs were extracted from −200 to 1000 ms time-locked to the onset of S2, with the prestimulus period used as the baseline. The extracted epochs were averaged separately for each condition (AS, AL, SS and SL), and than exported overall averages of all subjects. On the basis of previous reports and observations of the grand average waveforms, we averaged the amplitudes of N2 of the 280–380 ms time window and LPP of the 400–600 ms time window. A 2 × 2 × 3 × 3 within-subjects repeated measures analysis of variance (ANOVA) on the mean amplitudes of N2 was conducted in ERP analysis, taking celebrity (athlete star vs. singer star), brand (sport brand vs. leisure brand), localization (F: F3, Fz, F4; FC: FC3, FCz, FC4; C: C3, Cz, C4) and lateralization (left: F3, FC3, C3; middle: Fz, FCz, Cz; right: F4, FC4, C4) as within-participant factors. Similarly, we conducted the 2 (celebrity: athlete star vs. singer star) × 2 (brand: sport brand vs. leisure brand) × 3 (localization: C: C3, Cz, C4; CP: CP3, CPz, CP4; P: P3, Pz, P4) × 3 (lateralization: left: C3, CP3, P3; middle: Cz, CPz, Pz; right: C4, CP4, P4) repeated-measures ANOVA on the mean amplitudes of LPP. The Greenhouse–Geisser correction [25] was applied the statistical analyses if necessary.
As shown in Fig. 3, ANOVA results of N2 revealed that only a significant main effect of lateralization [F(2,44) = 8.145, p = 0.001, η2 = 0.270]. Additionally, an interaction effect between celebrity and brand was significant [F(1,22) = 6.632, p = 0.017, η2 = 0.232]. For lateralization effect, the pairwise comparison showed significant difference between left and middle lines (Mleft-middle = 1.116 μV, S.E. = 0.310, p = 0.002) and middle and right lines (Mmiddleright=−0.839 μV, S.E. = 0.268, p = 0.005), but not between left and right lines (Mleft-right = 0.277 μV, S.E. = 0.284, p = 0.341). Further analysis of simple effect revealed when the endorser was fixed with athlete stars, the N2 amplitude of AL condition (expertise incongruity) (M=−2.10 μV, S.E. = 0.538) was significantly larger than of AS condition (expertise congruity) (M=-1.50μV, S.E. = 0.557). While the endorser was fixed with singer stars, there was no significant difference [F(1,22) = 1.109, p = 0.304, η2 = 0.048] between sport and leisure brands (expertise neutrality). For LPP analysis, the ANOVA indicated the significant main effects of celebrity [F(1, 22) = 5.367, p = 0.030, η2 = 0.196], brand [F(1, 22) = 5.082, p = 0.034, η2 = 0.188] and localization [F(2, 44) = 23.110, p = 0.000, η2 = 0.512], and a significant interaction effect between celebrity and brand [F(1, 22) = 18.382, p = 0.000, η2 = 0.455]. For localization effect, the distribution of LPP showed a more posterior positive than anterior one (MP > MCP > MC). Besides, simple effect analysis indicated that the LPP difference between sport brands (AS: M = 3.11 μV, S.E. = 0.386) and leisure brands (AL : M = 1.99μV, S.E. = 0.369) endorsed by athlete stars was significant [F (1,22) = 20.722, p = 0.000, η2 = 0.485], but not significant endorsed by singer stars [F(1,22) = 2.076, p = 0.164, η2 = 0.086]. This analysis also showed that the LPP amplitude of AS condition (expertise congruity) was significantly larger than of SS condition (expertise neutrality) [F(1,22) = 18.464, p = 0.000, η2 = 0.456].
3. Results 3.1. Behavioral results The ANOVA of acceptance rates (ARs) showed that the main effects for celebrity [F(122) = 8.484, p = 0.008, η2 = 0.278] and brand [F (1,22) = 142.455, p = 0.000, η2 = 0.866] were significant, also the interaction effect of the two factors [F(1,15) = 146.981, p = 0.000, η2 = 0.870]. A simple effect analysis revealed that the ARs of AS condition (expertise congruity) was much higher than AL condition (expertise incongruity) [F(1,22) = 310.119,p < 0.000, η2 = 0.934], while there was no significant difference in expertise neutrality conditions (SS and SL) [F(1,22) = 1.730, p = 0.202, η2 = 0.073]. With respect to reaction time (RT), the ANOVA result showed a significant effect of celebrity [F(1,22) = 33.688, p = 0.000, η2 = 0.605], which indicated that subjects had a shorter RT toward athlete stars (M = 945.4 ms, S.E. = 125.83) than toward singer stars in ads (M = 1064.2 ms, S.E. = 121.27), namely, expertise neutrality required a longer response time. However, the brand effect [F (1,22) = 1.378, p = 0.253, η2 = 0.059] and their interaction effect was not significant [F(1,22) = 2.711, p = 0.114, η2 = 0.110] (see Fig. 2).
4. Discussion This current experiment explored the electrophysiological time course of subjects' perceiving of expertise congruencies by visually presenting different stimuli pairs of celebrities and brands. The obtained behavioral and ERPs results helped us to further understand the role of expertise congruency effect in ads from the brain. With respect to the results of acceptance rates (AR), we found that the AS condition obtained the highest AR while the AL condition obtained the lowest AR. On the basis of match-up hypothesis [3,7], the higher the internal matches between the celebrities and brands, the better the performance of ads. Thus, the results of AR were understandable because the high expertise congruency of celebrities and brands were a better fit in the memory of consumers, whereas the low expertise congruency endorsements had the worse fit. Additionally, the results of reaction time showed that the SS and SL condition (expertise
Fig. 2. Acceptance rates and reaction time of the celebrity-brand pairs (AS vs. AL and SS vs. SL) *P < .05; ns > .05. 3
Neuroscience Letters 712 (2019) 134436
H. Wang, et al.
Fig. 3. The grand-average ERP of the N2 and LPP elicited by four conditions [AS (expertise congruity), SL and SS (expertise neutrality), and AL (expertise incongruity), separately represented by black, blue, green and red line] from 5 midline electrodes. Arrows indicate the N2 around 280–380 ms and the LPP around 400–600 ms. See the online article for a color version of this figure.
the expertise association. This association triggered the memory recollection process with respect to expertise characteristics of celebritybrand and then induced a more positive LPP. Our findings suggested that the expertise congruity could help to enhance the effectiveness of relevant memory recollection, which to a certain extent facilitated subjects' accepting decision making, as evidenced by higher acceptance rates of AS condition than the other conditions. Furthermore, the results showed that the SS condition (expertise neutrality) produced a smaller LPP than AS condition (expertise congruity). Perhaps compared to athlete stars, singer stars endorsed sport brands that might not clearly arouse the retrieval of the expertise association in memory, thus leading to smaller LPP amplitudes. Thereby, consistent with prior studies [24,30], LPP here could particularly be treated as a reflection of memory recollection process of the expertise association between celebrities and brands.
neutrality) had a longer reaction time than AS (expertise congruity) and AL condition (expertise incongruity), which indicated that subjects were hesitate and need more time to choose in a neutral scenario. In terms of ERPs components, N2 was obviously identified (see Fig. 3). The results indicated that athlete stars endorse leisure brands, rather than sport brands, showed a more negative N2 component in the early process. As mentioned in the introduction, N2 has been reported to be associated with mismatch cognition [15,19]. Prior studies have shown that the N2 amplitude was enhanced when the next stimulus did not match the first [18,19,26]. On the basis of raw wave-forms and statistical analysis in our study, when the endorser was an athlete star, the second stimuli presenting a leisure brand (AL condition: expertise incongruity) rather than a sport brand (AS condition: expertise congruity) greatly contradicted the endorsers' expertise, which would cause a higher perceiving conflict. Meanwhile, N2 was widely indicated to reflect perceived risk in decisional process [24]. It was reported that higher perceived risk led to greater decisional conflict [24,27]. Thus, we guessed that the AL condition might also lead a higher distrust perception and conflict cognition, which required participants more psychological resources to process the celebrity-brand pairs, as evidenced by the longer reaction time for AL vs. AS condition. However, the difference in N2 between the SS condition and SL condition (expertise neutrality) was not significant. It meant when singer star was the endorser, the level of cognitive conflict with sport brands was similar to that with leisure brands. The differences of N2 amplitudes might reflect the degrees of expertise congruency in ads. As for the scalp distribution of N2, it mainly showed middle-line dominance. However, there was no significant hemisphere effect. This could be explained that the two hemispheres exhibited a homogeneous contribution during the perception of expertise congruency. Following N2, the emergence of LPP component from 400 to 600 ms was also observed (As seen in Fig. 3). As aforementioned above, LPP was purely sensitive to memory recollection and accuracy recognition [20,28,29]. In this study, our findings indicated the main effects and LPP interaction effect between celebrity and brand was significant. It showed that during the late cognitive processing stage, larger LPP amplitude was triggered in sport brands endorsed by athlete stars than that in leisure brands endorsed by athlete stars. However, the LPP differentiation between SS and SL condition was not obvious. It was possible that, athlete stars combined with sport brands (AS condition: expertise congruity) than leisure brands (AL condition: expertise incongruity) might more easily evoke the expertise association between celebrities and brands, whereas sport and leisure brands endorsed by singer stars (expertise neutrality) that might play equal roles in evoking
5. Conclusion The current experiment was the first to adopt ERPs to explore how subjects perceiving the expertise congruency effect and how it matters in celebrity/brand endorsements. The obtained behavioral results were consistent with the traditional studies of match-up hypotheses [3,4,7,8], and the ERPs results revealed the underlying neural mechanism of the perceiving process: early conflicted perception and later memory recollection processes. In detail, we found the expertise congruity scenario (AS) was more preferred by participants compared to expertise neutrality (SS and SL) and expertise incongruity scenario (AL). Corresponding to the perceiving process, this preference was separately reflected by a more negative N2 and positive LPP component. The N2 was mainly suggested to reflect the conflict process of celebritybrand, while the LPP referred to the recollection process of the expertise association. Generally, these findings imply that a more fluent processing (smaller N2 and larger LPP) and prominent performances could be obtained when a high expertise congruency is shown in ads, which may offer useful implications for marketing practices. Acknowledgement This work was supported by grant 18YJAZH079 from Humanities and Social Sciences Foundation of Ministry of Education of China, grant CXZZBS2018060 from Graduate Innovation Funding Project of Hebei Province, grant ZD2018208 from High School Science and Technology Planned Key Project (Natural Science) of Hebei Provincial Education Department, and grant 71171175 from National Natural Science 4
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Foundation of China.
NeuroQuantology 17 (2019) 97–103. [15] J.R. Folstein, P.C. Van, Influence of cognitive control and mismatch on the N2 component of the ERP: a review, Psychophysiology 45 (2008) 152–171. [16] K. Suchotzki, G. Crombez, F.T. Smulders, E. Meijer, B. Verschuere, The cognitive mechanisms underlying deception: an event-related potential study, Int. J. Psychophysiol. 95 (2015) 395–405. [17] Q. Ma, J. Jin, R. Yuan, W. Zhang, Who are the true fans? Evidence from an eventrelated potential study, PLoS One 10 (2015) e0129624. [18] Q. Ma, K. Wang, X. Wang, C. Wang, L. Wang, The influence of negative emotion on brand extension as reflected by the change of N2: a preliminary study, Neurosci. Lett. Suppl. 485 (2010) 237–240. [19] Q. Ma, X. Wang, S. Dai, L. Shu, Event-related potential N270 correlates of brand extension, Neuroreport 18 (2007) 1031–1034. [20] S. Bouaffre, A.F. Faita, Hemispheric differences in the time-course of semantic priming processes: evidence from event-related potentials (ERPs), Brain Cogn. 63 (2007) 123–135. [21] C. Todd, D.S. Handy, G. Lena, L. Cindy, W.S. Jonathan, ERP evidence for rapid hedonic evaluation of logos, J. Cogn. Neurosci. 22 (2009) 124–138. [22] S.B. Shannon, D.B. Jesse, K. Sajeev, K.P.W. Monika, Established liked versus disliked brands: brainactivity, implicit associations and explicit responses, Cogent Psychol. 3 (2016) 1176691. [23] M. Hou, A. Safron, K.A. Paller, C. Guo, Neural correlates of familiarity and conceptual fluency in a recognition test with ancient pictographic characters, Brain Res. 1518 (2013) 48–60. [24] Q. Shang, G. Pei, J. Jin, W. Zhang, Y. Wang, X. Wang, ERP evidence for consumer evaluation of copycat brands, PLoS One 13 (2018) e0191475. [25] S.W. Greenhouse, S. Geisser, On methods in the analysis of profile data, Psychometrika 24 (1959) 95–112. [26] C. Han, Y. Wang, M. Shi, W. Mao, W. Sun, Effect of methylphenidate on mismatched visual information processing in young healthy volunteers: an event-related potential study, Int. J. Clin. Exp. Med. 8 (2015) 9438–9445. [27] Q. Wang, L. Meng, M. Liu, Q. Wang, Q. Ma, How do social-based cues influence consumers’ online purchase decisions? An event-related potential study, Electron. Commer. Res. Appl. 16 (2016) 1–26. [28] D. Sabatinelli, P.J. Lang, A. Keil, M.M. Bradley, Emotionalperception: correlation of functional MRI and event-related potentials, Cereb. Cortex 17 (2007) 1085–1091. [29] M.R. San, Event-related potential studies of outcome processing and feedbackguided learning, Front. Hum. Neurosci. 6 (2012) 304–304. [30] S. Finnigan, M.S. Humphreys, S. Dennis, G. Geffen, ERP ‘old/new’effects: memory strength and decisional factor (s), Neuropsychologia 40 (2002) 2288–2304.
Appendix A. Supplementary data Supplementary material related to this article can be found, in the online version, at doi:https://doi.org/10.1016/j.neulet.2019.134436. References [1] H. Pringle, L. Binet, How marketers can use celebrities to sell more effectively, J. Consum. Behav. 4 (2005) 201–214. [2] N. Albert, L. Ambroise, F.P. Valette, Consumer, brand, celebrity: Which congruency produces effective celebrity endorsements? J. Bus. Res. 81 (2017) 96–106. [3] S.K. Koerning, T.C. Bord, The match-up effect and athlete endorsers for sport and non-sport brands, Sport Marketing Q. 18 (2009) 25–37. [4] D.T. Brian, B. Michael, The match-up hypothesis: physical attractiveness, expertise, and the role of fit on brand attitude, purchase intentions, and brand beliefs, J. Advert. 29 (2000) 1–13. [5] L. Zhou, P. Whitla, How negative celebrity publicity influences consumer attitudes: the mediating role of moral reputation, J. Bus. Res. 66 (2013) 1013–1020. [6] L. Bergkvist, K.Q. Zhou, Celebrity endorsements: a literature review and research agenda, Int. J. Advert. 35 (2016) 642–663. [7] M.A. Kamins, An investigation into the’ match-up’ hypothesis in celebrity advertising: when beauty may be only skin deep, J. Advert. 19 (1990) 4–13. [8] D.T. Brian, B. Michael, Matching products with endorsers: attractiveness versus expertise, J. Consum. Mark. 15 (1998) 576–586. [9] V. Klucharev, A. Smidts, G. Fernandez, Brain mechanisms of persuasion: how’ expert power’ modulates memory and attitudes, Soc. Cogn. Affect. Neurosci. 3 (2008) 353–366. [10] Y.S. Jung, Y.T. Kim, J.S. Baeck, J. Lee, The neural correlates of celebrity power on product favorableness: an fMRI study, NeuroQuantology 16 (2018) 50–58. [11] S.J. Luck, G.F. Woodman, E.K. Vogel, Event-related potential studies of attention, Trends Cogn. Sci. 4 (2000) 432–440. [12] Q. Ma, C. Wang, X. Wang, Two-stage categorization in brand extension evaluation: electrophysiological time course evidence, PLoS One 9 (2014) e114150. [13] J. Jin, C. Wang, L. Yu, Q. Ma, Extending or creating a new brand: evidence from a study on event-related potentials, Neuroreport 8 (2015) 572–577. [14] Z.J. Song, H. Wang, R. Shi, K.P. Jing, Neural correlates of consumers perceiving the stereotypes of brand personality: an event-related potentials study,
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Contents lists available at ScienceDirect
Neuroscience Letters journal homepage: www.elsevier.com/locate/neulet
Research article
How expertise congruency effect matters in celebrity/brand endorsements: Electrophysiological time course evidence
T
⁎
Hao Wang, Zjijie Song , Rui Shi, Yupeng Mei, Chang Liu School of Economics and Management, Yanshan University, No. 438, Heibei Road, Qinhuagndao, 066004, China
A R T I C LE I N FO
A B S T R A C T
Keywords: Celebrity-brand Expertise congruency effect Event-related potentials N2 LPP
Celebrity/brand endorsement is omnipresent and has great influence on consumers. In the current study, the event-related potentials (ERPs) were utilized to explore the neural process underlying how expertise congruency effect matters in ads. Twenty-five participants (two excluded) were recruited to accept or refuse the brands (stimulus 2) endorsed by celebrities (stimulus 1) during a S1–S2 paradigm. Behavioral results indicated significant differences in the acceptance rates and reaction time, while ERPs component provided further insight into the cognitive processing: early conflicted perception and later memory recollection process. The results of ERPs showed that, when the celebrity is an athlete star, presenting a sport brand (AS, expertise congruity) triggered a less negative N2 and a larger LPP component compared to a leisure brand (AL, expertise incongruity) but not different with singer star (SS and SL, expertise neutrality). We suggested the N2 may reflect the conflict process of celebrity-brand, while the LPP may demonstrate the recollection process of expertise association in memory. Such findings implied that a more fluent processing (smaller N2 and larger LPP) and prominent performances could be obtained in an expertise congruity scenario, which deepened our understanding of expertise congruency effect in advertising.
1. Introduction Celebrity/brand endorsements enjoy using celebrities for enhancing marketing communications [1,2]. In fact, celebrity status emerges from a variety of sources such as film acting, music, etc., one major source of fame is athletic prowess. Although athletes have appeared as endorsers for brands including Nike, Coca-Cola, Pizza Hut, etc., the performance of these ads is not necessarily as good as expected. Many suggest that expertise with the product that is related in some way to athletic performance can make for a better fit with the endorsed product. Namely, consumers would naturally see more of a fit between an athlete endorser and a sport brand than between an athlete and a non-sport brand [3,4]. Companies are obsessed with celebrity endorsements, but the associations with celebrity do not automatically benefit the brand [5,6], a deep understanding of the mechanisms of expertise effect remains a significant goal for researches. As the "match-up hypothesis" suggests, the inherent match or consistency between celebrities and brands makes endorsement more effective [7]. Especially, the match should reflect the salient attributes of the brand and the distinctive characteristics of the celebrity [6,8]. Some traditional marketing studies have shown that expertise is widely considered as an important dimension for driving the fit between an ⁎
endorser and a brand [4,6,8]. In advertising, consumers are always exposed to hundreds of short ads in one form or another: from web ads to TV commercials and others information. How they quickly perceiving the expertise of endorsers and the matching-up with brands, involves the effectiveness and acceptance of the brands. However, it is a pity that the expertise congruency effect in celebrity/brand endorsements has nearly been ignored by cognitive neuroscientists. In recent years, neural methods are increasing adopted in advertising. A study using functional magnetic resonance imaging (fMRI) finds an increase in activity in the medial orbitofrontal cortex (mOFC) underlying the processing of celebrity–product pairings [9]. It shows that a single exposure to a combination of expert and product leads to a long-lasting positive effect on memory and attitude towards product, whereas non-expert endorser does not [9,10]. Compared to fMRI, event-related potentials (ERPs) have high time resolution, allowing researchers instantaneously assess the subject's underlying neural activities and determine how early a cognitive process takes place [11,12]. Thus, in the current study, we focus on athlete and singer celebrities (representing different expertise), take celebrities to manipulate the expertise congruency with a particular brand (e.g. sport or leisure brand), utilize ERPs to explore how subjects perceiving the expertise congruency and how it matters in celebrity-brand endorsements.
Corresponding author. E-mail address: [email protected] (Z. Song).
https://doi.org/10.1016/j.neulet.2019.134436 Received 10 May 2019; Received in revised form 7 August 2019; Accepted 14 August 2019 Available online 31 August 2019 0304-3940/ © 2019 Published by Elsevier B.V.
Neuroscience Letters 712 (2019) 134436
H. Wang, et al.
Fig. 1. Experimental procedure: participants were instructed to decide whether to accept the brand endorsed by the presented celebrity.
names). Stimulus 1 was celebrity name selected from one of two expertise backgrounds (6 athlete stars and 6 singer stars).A 5 Likert Scale questionnaire was adopted to investigate their reputation (Mathlete stars = 3.92, Msinger stars = 4.03, t=−1.41, p = 0.188) and popularity (Mathlete stars = 4.09, Msinger stars = 4.13, t=−0.41, p = 0.694). Besides, there was no difference in the familiarity of these stars (Mathlete stars = 3.76, Msinger stars = 3.85, t=−1.02, p = 0.262). Stimulus 2 was brand name selected from one of two categories (10 sport brands and 10 leisure brands). All the brands were chosen from the Well-known Trademark List of the China Trademark Office, which sport brands included Adidas, Anta (famous local clothing brand) and leisure brands included Playboy and Yishion (famous local clothing brand), etc. A pretest questionnaire indicated that a singer’ expertise association with sport and leisure brands is generally neutral, but the association between an athlete and the above brands is quite different. Thus, stimulating pictures are created in different sets: (i) expertise congruity: athlete star endorses sport brand, AS; (ii) expertise neutrality: singer star endorses sport brand, SS; (iii) expertise neutrality: singer star endorses leisure brand, SL; (iv) expertise incongruity: athlete star endorses leisure brand, AL. Each set has 60 pairs consisted of a celebrity and a brand name (limited to no more than four Chinese characters on a gray background).
Previous studies show that ERPs have been defined as different components and widely used to reveal particular cognitive processes [13,14]. Among them, N2 component is sensitive to cognitive conflict, reflecting the mismatch of pair stimulus [15,16]. In a neurological study of celebrity fans, larger N2 is observed in response to the photos of familiar or unfamiliar people rather than celebrity, reflecting the inhibition of action because of fans' anticipation of their favorite celebrity [17]. Besides, researches on brand extension evaluation have shown the higher N2 amplitude evoked in the early process if the extension product name was not related to the brand name in terms of category [18,19]. So, what if subjects encounter a perceptual expertise congruity/incongruity of the endorser and brand in short ads? In current experiment, as the paradigm is adapted from a word-pair paradigm suggested by M Qingguo, et al. [19], we expect N2 can be an index of expertise congruencies. In addition to N2, the LPP, as a slow centro-parietal positive component occurred between 400 and 800 ms, has been reported to be associated with recollection [20], which is accompanied by emotional processing [21,22]. Research finds that the LPP enhancement is elicited for familiar compared with unfamiliar stimuli [23]. In a study, due to the easily active association of the imitated leading brand and its products, a larger LPP is evoked with near copycat branded product than with far copycat branded product [24]. In the same way, in our study we hope when celebrity endorses a brand that closely relevant/irrelevant to his/her expertise, a similar pattern of LPP might be observed in later stage by analogy. Based on the above analyses, we assumed that examining the N2 amplitude could help elucidate whether or how subjects are sensitive to the expertise congruencies, while the LPP amplitude in later process could deeply reveal how the spontaneous retrieval of explicit expertise memories associated with celebrity-brand in ads. This experiment aimed to test the hypothesis and explored the neuronal mechanism of expertise congruency effect, especially the time course of expertise perception between celebrity and brand.
2.3. Procedure Participants sat comfortably in a closed laboratory 70 cm away from a LCD screen. All stimuli pairs (S1-S2) were classified into 4 blocks, each consisted of 60 trials, programmed and presented using E-Prime 2.0 software (Psychology Software Tools, Pittsburgh, PA, USA) in a pseudorandom order with a visual angle of 2.85° × 1.37°. In detail (see Fig. 1), each trial began with a fixation cross against a gray background for 500 ms. After a random blank interval (400–600 ms), S1 (celebrity names) was appeared for 1500 ms, followed by a blank interval for 400–600 ms randomly before S2 (brand names) was presented for 3000 ms. The target stimuli (S2) would disappear until a response, followed by a blank interval for 400–600 ms. Participants were instructed to decide whether to accept the brand endorsed by the presented celebrity in consideration of their expertise associations. Left button means accepted and right button means unaccepted. The response-to-hand assignments were counter balanced across the participants.
2. Methods 2.1. Participants Twenty-five healthy graduates and undergraduates participated in this experiment approved by the Internal Review Board of Cognitive Neuroscience Lab at Yanshan University. All subjects were right-handed and native Chinese speakers, reported normal or corrected-to-normal vision without any history of neurological or mental diseases. Written informed consent was obtained from each subject before the formal experiment. Data of two subjects were excluded for excessive artifacts during EEG recording, resulting in 23 valid subjects (10 male) aged 24.2 (SD = 2.8, range = 22–26) years.
2.4. EEG recording and analysis EEG data was recorded (band pass 0.01–100 Hz, sampling rate 500 Hz) with a Brain actiCHamp amplifier (Brain Products GmbH, Munich, Germany), using an electrode cap with 64 Ag/AgCl electrodes according to the extended international 10–20 system and referenced to linked mastoids. The cephalic location was served as the ground. Horizontal and vertical electro-oculograms were recorded through electrodes placed 10 mm from the lateral canthi of both eyes and above and below the left eye. Impedances were kept below 5 kΩ during the
2.2. Stimulus materials The stimuli consisted of 240 pairs (12 celebrity names × 20 brand 2
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3.2. ERPs results
research. BrainVision Analyzer 2.1 was used to process the collected data offline. The average of left and right mastoids was transformed as the new references, and Ocular Correction ICA was used to exclude EOG artifacts followed by 16 Hz (24 dB/octave) digital low pass filter. Trials containing electromyography activity, other artifacts, or peak-to-peak deflection exceeding ± 100 μV were excluded. EEGs were extracted from −200 to 1000 ms time-locked to the onset of S2, with the prestimulus period used as the baseline. The extracted epochs were averaged separately for each condition (AS, AL, SS and SL), and than exported overall averages of all subjects. On the basis of previous reports and observations of the grand average waveforms, we averaged the amplitudes of N2 of the 280–380 ms time window and LPP of the 400–600 ms time window. A 2 × 2 × 3 × 3 within-subjects repeated measures analysis of variance (ANOVA) on the mean amplitudes of N2 was conducted in ERP analysis, taking celebrity (athlete star vs. singer star), brand (sport brand vs. leisure brand), localization (F: F3, Fz, F4; FC: FC3, FCz, FC4; C: C3, Cz, C4) and lateralization (left: F3, FC3, C3; middle: Fz, FCz, Cz; right: F4, FC4, C4) as within-participant factors. Similarly, we conducted the 2 (celebrity: athlete star vs. singer star) × 2 (brand: sport brand vs. leisure brand) × 3 (localization: C: C3, Cz, C4; CP: CP3, CPz, CP4; P: P3, Pz, P4) × 3 (lateralization: left: C3, CP3, P3; middle: Cz, CPz, Pz; right: C4, CP4, P4) repeated-measures ANOVA on the mean amplitudes of LPP. The Greenhouse–Geisser correction [25] was applied the statistical analyses if necessary.
As shown in Fig. 3, ANOVA results of N2 revealed that only a significant main effect of lateralization [F(2,44) = 8.145, p = 0.001, η2 = 0.270]. Additionally, an interaction effect between celebrity and brand was significant [F(1,22) = 6.632, p = 0.017, η2 = 0.232]. For lateralization effect, the pairwise comparison showed significant difference between left and middle lines (Mleft-middle = 1.116 μV, S.E. = 0.310, p = 0.002) and middle and right lines (Mmiddleright=−0.839 μV, S.E. = 0.268, p = 0.005), but not between left and right lines (Mleft-right = 0.277 μV, S.E. = 0.284, p = 0.341). Further analysis of simple effect revealed when the endorser was fixed with athlete stars, the N2 amplitude of AL condition (expertise incongruity) (M=−2.10 μV, S.E. = 0.538) was significantly larger than of AS condition (expertise congruity) (M=-1.50μV, S.E. = 0.557). While the endorser was fixed with singer stars, there was no significant difference [F(1,22) = 1.109, p = 0.304, η2 = 0.048] between sport and leisure brands (expertise neutrality). For LPP analysis, the ANOVA indicated the significant main effects of celebrity [F(1, 22) = 5.367, p = 0.030, η2 = 0.196], brand [F(1, 22) = 5.082, p = 0.034, η2 = 0.188] and localization [F(2, 44) = 23.110, p = 0.000, η2 = 0.512], and a significant interaction effect between celebrity and brand [F(1, 22) = 18.382, p = 0.000, η2 = 0.455]. For localization effect, the distribution of LPP showed a more posterior positive than anterior one (MP > MCP > MC). Besides, simple effect analysis indicated that the LPP difference between sport brands (AS: M = 3.11 μV, S.E. = 0.386) and leisure brands (AL : M = 1.99μV, S.E. = 0.369) endorsed by athlete stars was significant [F (1,22) = 20.722, p = 0.000, η2 = 0.485], but not significant endorsed by singer stars [F(1,22) = 2.076, p = 0.164, η2 = 0.086]. This analysis also showed that the LPP amplitude of AS condition (expertise congruity) was significantly larger than of SS condition (expertise neutrality) [F(1,22) = 18.464, p = 0.000, η2 = 0.456].
3. Results 3.1. Behavioral results The ANOVA of acceptance rates (ARs) showed that the main effects for celebrity [F(122) = 8.484, p = 0.008, η2 = 0.278] and brand [F (1,22) = 142.455, p = 0.000, η2 = 0.866] were significant, also the interaction effect of the two factors [F(1,15) = 146.981, p = 0.000, η2 = 0.870]. A simple effect analysis revealed that the ARs of AS condition (expertise congruity) was much higher than AL condition (expertise incongruity) [F(1,22) = 310.119,p < 0.000, η2 = 0.934], while there was no significant difference in expertise neutrality conditions (SS and SL) [F(1,22) = 1.730, p = 0.202, η2 = 0.073]. With respect to reaction time (RT), the ANOVA result showed a significant effect of celebrity [F(1,22) = 33.688, p = 0.000, η2 = 0.605], which indicated that subjects had a shorter RT toward athlete stars (M = 945.4 ms, S.E. = 125.83) than toward singer stars in ads (M = 1064.2 ms, S.E. = 121.27), namely, expertise neutrality required a longer response time. However, the brand effect [F (1,22) = 1.378, p = 0.253, η2 = 0.059] and their interaction effect was not significant [F(1,22) = 2.711, p = 0.114, η2 = 0.110] (see Fig. 2).
4. Discussion This current experiment explored the electrophysiological time course of subjects' perceiving of expertise congruencies by visually presenting different stimuli pairs of celebrities and brands. The obtained behavioral and ERPs results helped us to further understand the role of expertise congruency effect in ads from the brain. With respect to the results of acceptance rates (AR), we found that the AS condition obtained the highest AR while the AL condition obtained the lowest AR. On the basis of match-up hypothesis [3,7], the higher the internal matches between the celebrities and brands, the better the performance of ads. Thus, the results of AR were understandable because the high expertise congruency of celebrities and brands were a better fit in the memory of consumers, whereas the low expertise congruency endorsements had the worse fit. Additionally, the results of reaction time showed that the SS and SL condition (expertise
Fig. 2. Acceptance rates and reaction time of the celebrity-brand pairs (AS vs. AL and SS vs. SL) *P < .05; ns > .05. 3
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Fig. 3. The grand-average ERP of the N2 and LPP elicited by four conditions [AS (expertise congruity), SL and SS (expertise neutrality), and AL (expertise incongruity), separately represented by black, blue, green and red line] from 5 midline electrodes. Arrows indicate the N2 around 280–380 ms and the LPP around 400–600 ms. See the online article for a color version of this figure.
the expertise association. This association triggered the memory recollection process with respect to expertise characteristics of celebritybrand and then induced a more positive LPP. Our findings suggested that the expertise congruity could help to enhance the effectiveness of relevant memory recollection, which to a certain extent facilitated subjects' accepting decision making, as evidenced by higher acceptance rates of AS condition than the other conditions. Furthermore, the results showed that the SS condition (expertise neutrality) produced a smaller LPP than AS condition (expertise congruity). Perhaps compared to athlete stars, singer stars endorsed sport brands that might not clearly arouse the retrieval of the expertise association in memory, thus leading to smaller LPP amplitudes. Thereby, consistent with prior studies [24,30], LPP here could particularly be treated as a reflection of memory recollection process of the expertise association between celebrities and brands.
neutrality) had a longer reaction time than AS (expertise congruity) and AL condition (expertise incongruity), which indicated that subjects were hesitate and need more time to choose in a neutral scenario. In terms of ERPs components, N2 was obviously identified (see Fig. 3). The results indicated that athlete stars endorse leisure brands, rather than sport brands, showed a more negative N2 component in the early process. As mentioned in the introduction, N2 has been reported to be associated with mismatch cognition [15,19]. Prior studies have shown that the N2 amplitude was enhanced when the next stimulus did not match the first [18,19,26]. On the basis of raw wave-forms and statistical analysis in our study, when the endorser was an athlete star, the second stimuli presenting a leisure brand (AL condition: expertise incongruity) rather than a sport brand (AS condition: expertise congruity) greatly contradicted the endorsers' expertise, which would cause a higher perceiving conflict. Meanwhile, N2 was widely indicated to reflect perceived risk in decisional process [24]. It was reported that higher perceived risk led to greater decisional conflict [24,27]. Thus, we guessed that the AL condition might also lead a higher distrust perception and conflict cognition, which required participants more psychological resources to process the celebrity-brand pairs, as evidenced by the longer reaction time for AL vs. AS condition. However, the difference in N2 between the SS condition and SL condition (expertise neutrality) was not significant. It meant when singer star was the endorser, the level of cognitive conflict with sport brands was similar to that with leisure brands. The differences of N2 amplitudes might reflect the degrees of expertise congruency in ads. As for the scalp distribution of N2, it mainly showed middle-line dominance. However, there was no significant hemisphere effect. This could be explained that the two hemispheres exhibited a homogeneous contribution during the perception of expertise congruency. Following N2, the emergence of LPP component from 400 to 600 ms was also observed (As seen in Fig. 3). As aforementioned above, LPP was purely sensitive to memory recollection and accuracy recognition [20,28,29]. In this study, our findings indicated the main effects and LPP interaction effect between celebrity and brand was significant. It showed that during the late cognitive processing stage, larger LPP amplitude was triggered in sport brands endorsed by athlete stars than that in leisure brands endorsed by athlete stars. However, the LPP differentiation between SS and SL condition was not obvious. It was possible that, athlete stars combined with sport brands (AS condition: expertise congruity) than leisure brands (AL condition: expertise incongruity) might more easily evoke the expertise association between celebrities and brands, whereas sport and leisure brands endorsed by singer stars (expertise neutrality) that might play equal roles in evoking
5. Conclusion The current experiment was the first to adopt ERPs to explore how subjects perceiving the expertise congruency effect and how it matters in celebrity/brand endorsements. The obtained behavioral results were consistent with the traditional studies of match-up hypotheses [3,4,7,8], and the ERPs results revealed the underlying neural mechanism of the perceiving process: early conflicted perception and later memory recollection processes. In detail, we found the expertise congruity scenario (AS) was more preferred by participants compared to expertise neutrality (SS and SL) and expertise incongruity scenario (AL). Corresponding to the perceiving process, this preference was separately reflected by a more negative N2 and positive LPP component. The N2 was mainly suggested to reflect the conflict process of celebritybrand, while the LPP referred to the recollection process of the expertise association. Generally, these findings imply that a more fluent processing (smaller N2 and larger LPP) and prominent performances could be obtained when a high expertise congruency is shown in ads, which may offer useful implications for marketing practices. Acknowledgement This work was supported by grant 18YJAZH079 from Humanities and Social Sciences Foundation of Ministry of Education of China, grant CXZZBS2018060 from Graduate Innovation Funding Project of Hebei Province, grant ZD2018208 from High School Science and Technology Planned Key Project (Natural Science) of Hebei Provincial Education Department, and grant 71171175 from National Natural Science 4
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Foundation of China.
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