The hidden persuaders break into the tired brain q
Christina Bermeitinger a,*,Ruben Goelz a ,Nadine Johr a ,Manfred Neumann a ,Ullrich K.H.Ecker b ,Robert Doerr a
a Saarland University,Department of Psychology,Campus A24,D –66123Saarbruecken,Germany b
School of Psychology,University of Western Australia,Crawley,Australia
a r t i c l e i n f o Article history:
Received 30July 2007
Revid 22September 2008
Available online 10October 2008
Keywords:
Subliminal priming Subliminal persuasion Advertiment
Subliminal advertising
Need-related subliminal stimuli Level of tiredness
Motivation for concentration enhancement
a b s t r a c t
There is a long-lasting debate on whether subliminal advertising actually works.In this context there are some studies suggesting that subjects’motivation is a crucial point.Karremans et al.[Karremans,J.C.,Stroebe,W.,&Claus,J.(2006).Beyond Vicary’s fantasies:The impact of subliminal priming and brand choice.Journal of Experimental Social Psychology,42,792–798]showed that subjects were influenced in their intention to drink a specific brand of soft drink by a subliminally prented brand prime,but only if they were thirsty.In the prent study,we adapted their paradigm to the concept of ‘concentration’and embedded the subliminal prentation of a brand logo into a computer game.Actual subquent con-sumption of dextro pills (of the prented or a not prented brand)was measured dependent on the level of participants’tiredness and the subliminally prented logo.We found the same pattern as Karremans et al.(2006):only tired participants consumed more of the subliminally prented than the not prented brand.Therefore,the findings confirm that subjects are influenced by subliminally pre-nted stimuli if the stimuli are need-related and if subjects are in the matching motivational state.
Ó2008Elvier Inc.All rights rerved.
Introduction
Recently,Karremans,Stroebe,and Claus (2006)revived the debate about subliminal persuasion.They connected the subliminal priming of a brand name and the choice of this brand over control brands with participants’goals or needs:only thirsty participants (who were thought to have the specific goal to quench their thirst)cho the primed drink over the others more often.Considering the history of findings around subliminal persuasion,to replicate and even extend or generalize the found effect ems both challenging and vital.
Indeed,there is a long-lasting debate on the possibilities and boundaries of subliminal advertising (for reviews,e Dijksterhuis,Aarts,&Smith,2005;Theus,1994).The well known story of the marketing expert James Vicary reprents a milestone of this de-bate.He claimed that he had incread the sales of popcorn and Coca Cola by 57.7%and 18.1%after the subliminal prentation of the slogans ‘‘Drink Coca Cola”and ‘‘Eat Popcorn”in a movie (e.g.,Brand,1978;Henderson,1957).By 1962at the latest,this was expod as a publicity hoax.Nevertheless,till today the story is living as a modern legend (e.g.,Pratkanis,1992;Rogers,1993;Rogers &Smith,1993).
Karremans et al.(2006)showed that some of Vicary’s fantasies are maybe actually not so farfetched.In their first experiment,Kar-remans et al.(2006)prented a subliminal stimulus –for the experimental group the brand name ‘‘Lipton Ice”,for the control group the neutral string ‘‘Npeic Tol”–25times within a visual detection task.Afterwards,participants had to make a virtual choice between Lipton Ice and Spa Rood,a common mineral water.Then,they answered questions about their intention to drink Lip-ton Ice,Coca Cola,and Spa Rood.Finally,the level of thirstiness was measured with two further items.There was a positive associ-ation between the amount of thirst and the likelihood to choo Lipton Ice (compared to Spa Rood)and between the amount of thirst and the intention to drink Lipton Ice only in the Lipton Ice prime condition,not in the ‘‘Npeic Tol”prime condition.In a c-ond experiment,the authors manipulated the amount of thirst with a salty sweet (to increa feelings of thirst)for half of the par-ticipants.Afterwards,subjects ran through exactly the same cour as in the first experiment.The main findings could be replicated:the subliminal prentation of a drink’s name incread the choice-probability for this drink and the intention to drink this beverage only for thirsty individuals.
The study is perfectly in line with assumptions (and rearch which confirms the assumptions)that one can be subliminally influenced only if one is in a corresponding state with a lective vigilance (s
ee Bruner &Postman,1947);that is,if the prime is in relation to one’s current goals or needs (e.g.,Brand,1978;Strahan,Spencer,&Zanna,2002;Strahan,Spencer,&Zanna,2005;and even Vicary himlf assumed that in 1958,e Rogers,1993).
0022-1031/$-e front matter Ó2008Elvier Inc.All rights rerved.doi:10.1016/j.jesp.2008.10.001
q
The rearch reported in this article was supported by intact GmbH (Hesnweg 10,D –48157Muenster,www.intact-ms.de )who sponsored the dextro pills.We thank Dirk Wentura,Christian Frings,Andrea Paulus,Michaela Rohr,Joel Cooper and one anonymous reviewer for helpful and detailed comments on an earlier version of this paper.
*Corresponding author.Fax:+496813024049.
E-mail address:cbermeit@mx.uni-saarland.de (C.Bermeitinger).Journal of Experimental Social Psychology 45(2009)
320–326海上钢琴师英语影评
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j o u r n a l h o m e p a g e :w w w.e l s e v i e r.c o m /l o c a t e /j e s
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The results of Karremans et al.(2006)reprent a rious example of subliminal manipulation of choice behavior with scientific means after a long period with hundreds of mass media papers that mostly pursued this question only insuffi,Pratkanis&Greenwald,1988). But one could argue that the study is only one more study amongst the hundred others which were–with random assignment–some-times able to show subliminal persuasion and sometimes not.Brannon and Brock(
1994)described the problem around the lacking reproduc-tion of a subliminal persuasion effect,fittingly,as a script for a drama with three acts:first,obrvation of an effect in thefield;cond,dem-onstration of the effect in a laboratory analogue;third,subquent fail-ure to reproduce the effect.Therefore,the vast majority of the psychological community concluded that subliminal persuasion does not and could not work(for example Broyles,2006;Dijksterhuis et al.,2005;George&Jennings,1975;Moore,1988;Pratkanis&Aron-son,1992;Pratkanis&Greenwald,1988;Trappey,1996).
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Given the lack of supporting evidence,a replication of Karremans et al.(2006)findings is urgently needed.Besides the importance to replicate their effect,however,the study leaves open questions and,at one point,shares a common problem that many previous studies have been criticized for;that is,the test of stimuli’s ,Beatty&Hawkins,1989;Brand,1978;Brannon&Brock, 1994;Merikle,Smilek,&Eastwood,2001;Saegert,1979).This ems to be especially important considering the fact that prime duration in their study was quite long(23ms).There are a lot of studies in which at least some participants showed high performances in di-rect prime detection tests with even shorter prentation times of ,Greenwald,Draine,&Abrams,1996).
The prent rearch
In the prent study,we wanted to take up the experiments from Karremans et al.(2006)and conceptually replicate theirfind-ings.Additionally,we wanted to expand their results;in particular, we measured the primes’subliminality in the actual prime study’s participants and we measured actual consumption behavior rather than just the intention to behave.
First of all,we cho a need other than thirst to go one step beyond simple physiological needs.We decided to u the concept of‘con-centration’.Tired persons need to put more effort into a task in an achievement situation thanfit persons.Therefore,tired persons should have the motivation to enhance their concentration.Of cour,thefirst wish of a tired person would be to take a rest or sleep for a while.But most often(in the lab and in everyday life as well)this possibility is no real alternative.In the lab,participants give their connt to concentrate and do the best they can.And in everyday life, you only have to imagine a night-time car journey,during which it is vital to focus on the task and mobilize your rerve resources despite fatigue.We call this motivation the‘motivation for concentration enhancement’(MfCE)and we assume that tired participants in par-ticular have this need.This assumption was tested and corroborated with25subjects who did not participate in the main experiment.1As an equivalent to the drinks in the Karremans et al.(2006)study,we cho dextro pills–a popular means of concentration enhancement in achievement situations.
Second,we did not measure participants’intention to consume a product,but their actual consumption(of a primed and a non-primed‘product’)within the cour of the experiment.We con-sider this a more nsitive and valid measure than the virtual choice of one of two alternatives(e also literature on the inten-tion-behavior gap;for an example in a purchasing context,e Miniard,Obermiller,&Page,1983).First,real consumption behav-ior is probably less influenced by strategical thinking than virtual choice behavior.Second,we can analyze the behavior of one per-son regarding both primed and non-primed‘brands’.Andfinally, it allows us to measure behavior over a longer period of time, and also after participants have made some experience with the different‘products’.
A third difference is that we did not u common brands. The two logos we ud were designed especially for this study. Additionally,one logo was subliminally prented to one half of the subjects,the other logo was subliminally prented to the other half of the subjects.This counterbalancing allowed us to compare consumption behavior between both‘brands’instead of comparing the subliminally prented brand and a further control brand(as in Karremans et al.,2006).It has been dis-cusd that influencing someone’s consumer behavior may be simpler when concerned with neutral stimuli in comparison to already familiar ,Dijksterhuis et al.,
2005).Neverthe-less,we cho this procedure becau our interest was the manipulation of consumer behavior in terms of a relative com-parison of two(novel)brands,not regarding a change of an a priori preference.
Fourth,after the main experiment and for each participant, we ran a direct test to objectively asss discrimination perfor-mance regarding the two logos,as recommended by Merikle et al.(2001).Karremans et al.(2006)ran a direct test with p-arate participants,asking them to report the subliminally pre-nted word.Our approach was to ask subjects to make veral two-alternative forced choices–lect the logo that was subliminally prented earlier–,which we consider a sim-pler and thus more nsitive task.Hence,if a participant suc-cessfully differentiated between the two ,detected the previously prented logo),we concluded that behavior may have been bad on some supraliminal details.Such an individual measure of discrimination performance also allowed us to check whether an effect hinges on participants with good or bad performance.
Last but not least,we embedded the subliminal prentation in a computer game,which constitutes a less artificial context than tho ud in most of the previous studies.
Methods
Participants
The sample consisted of64(18male,46female)participants from Saarland University(Md=21years,ranging from19to49). They received experimental credits for their participation and had the chance to win vouchers for the movie theater.All partic-ipants had normal or corrected to normal vision.Three subjects were excluded from the analysis becau of very low scores (below3points)on the Inventar Komplexer Aufmerksamkeit (INKA,inventory for complex attention;Heyde,2000),testing concentration performance(e below);the subjects likely did not understand instructions or were not motivated to follow them.
1We tested the relation of the level of tiredness and MfCE.Both were continuous
variables bad on participants’lf-ratings.Materials and the procedure were similar
to the main experiment but without the direct test of discrimination performance
concerning the subliminal stimuli and without different choices of primed or non-
primed pills:the dextro pills were offered in only one bowl which was not labeled
with any logo,and the bowl contained20dextro pills.Subjects played the computer
game and were then given28questions mainly targeting their effort or strategies
during the game and how supporting the consumption of dextro was.Among the,
the critical question appeared:‘‘How strong was your need to enhance your level of
concentration before or during the game?”[2=very,À2=not at all].Overall,
participants had no significant motivation for concentration enhancement,M=0.28
(SE=0.25),t(24)=1.13,p=.27.Yet,most importantly,the correlation between the
level of tiredness and MfCE was significant,r=.52,p<.01;the more tired participants
student的音标
were,the higher was their need to enhance their concentration level.Thus,the result
is perfectly in line with our prediction.
C.Bermeitinger et al./Journal of Experimental Social Psychology45(2009)320–326321
Design
The design comprid factors‘subliminal prime’(logo A vs.logo B)and‘level of tiredness’(continuous variable bad on partici-pants’lf-rating).Each participant was shown either logo A or logo B.The number of consumed dextro pills from product A and product B(‘consumption’)rved as the dependent variables.
分毫
Materials
培训机构招生We designed10colored logos(each with a graphical background and the writing‘Dextro’)that were tested in a pretest with39sub-jects who did not take part in the main experiment.Two logos(for black-and-white versions e Fig.1)were lected as subliminal stimuli becau of comparable preferences in the pretest.Both logos could be imagined as logos for a dextro brand and they were cho-n equally often as the preferred logo.The logos did not differ with regard to their size(7.9cm in width,5.8cm in height)and their mean luminance.The dominant colors of both logos were black,red,white, and yellow.A mask was created by decomposing each of the two lo-gos into40parts.Then,20parts of each logo,respectively,were new-ly put together(ensuring that darker parts were predominantly ud for outer areas of the image,as in the original logos;for a black-and-white version e Fig.1c).Dextro pills with a diameter of2cm,a weight of2g,and a slight citric taste rved as products that could be consumed during breaks.They were offered in two small bowls posi
tioned side-by-side on the left-hand side of the monitor;the bowls were covered until thefirst consumption break.Each bowl contained10pills;one of the logos(defining product A and product B,respectively)was pasted onto each bowl;the positioning of bowls (i.e.,the assignment of logos to left/right bowls)was counterbal-anced across subjects.
For the prentation of the subliminal logos,we designed a sim-ple two-dimensional jump-and-reach computer game in E-Prime (version1.1,SP3,Psychology Software Tools,Inc.,Pittsburgh,PA, USA).In this game,a green avatar manikin(3cm in height)walked on a gray wall(which occupied the lower6cm of the screen)and jumped when the up-arrow-key was presd.By doing so,the man-ikin could collect bundles of banknotes thatflew into the screen from the right-hand side.For each collected bundle,one point was added to the playing score(which was shown in the right-upper corner). Additionally,the manikin had to jump over campfires that also emerged on the right-hand side.Two points were taken off the score if the manikin did not succeed in doing so.To make it more difficult, the speed of the incoming objects was incread with increasing duration of the game.The background consisted offlickeringflames to conceal the subliminal stimulus prentations.
The logos and the mask were prented to the upper right of the manikin.This position was chon becau it was the place most likely attended by participants becau the game ,notes an
dfires)appeared on the right-hand side.Procedure
Participants were tested in groups of up to four people.The experiment was run on IBM-compatible PCs using E-Prime soft-ware and17’’CRT-monitors with a refresh rate of100Hz.Unless otherwi noted,all instructions and tasks were given on the com-puter screen.
In thefirst pha,subjects gave their connt to participate vol-untarily and with their full engagement.Participants were told that the goal of the experiment was to test if the individual lf-deter-mined consumption of dextro influenced concentration and per-formance in a computer game.They were told that we had two different sponsors for the dextro pills(which nevertheless had similar taste and composition),such that they had two different products to choo from.Subjects were additionally motivated with the chance to win vouchers for the movie theater,which were given to the participant with the highest score within their group.
In the cond pha,participants were requested to answer some questions about their actual state,their leisure time,and their consumption of various ,coffee,tea,or energy drinks)in concentration-demanding situations.Within the ques-tions,participants’tiredness was measured with twofive-point items:‘‘Today ”[À2=well rested,2=not well rested],‘‘At the moment
mistake的用法I ”[À2=fit,2=tired].The scores on the items were averaged to create an index of tiredness.
In the third pha,participants were acquainted with the com-puter game with appropriate instructions and a two-minute prac-tice block.This practice block was exactly the same as the following game blocks within thefifth pha(e below),except that the score was not included into the overall score of the partic-ipants.Within each ,during the ongoing game),there were three quences.In thefirst quence A,which lasted30s, the word‘‘Konzentration”(concentration; 5.5cm in width, 0.5cm in height)was subliminallyflashed on the screen in red to enhance or trigger subjects’motivation for concentration.The word was prented at the same position as the subliminally pre-nted logo;prentation time was10ms,with an inter-trial inter-val(ITI)of3000ms.During the cond quence B(30s),the word ‘‘Konzentration”and the subliminally prented logo were pre-nted alternately:Prentation started with the ,the prime;10ms),which was replaced by the mask(10ms);after an ITI of3000ms,‘‘Konzentration”was prented for10ms,and so on.In the last quence C(60s),only the subliminal prime (10ms)followed by the mask(10ms)were prented concu-tively with a3000ms ITI.
In the fourth pha,participants received the paper and pencil version of the INKA(Heyde,2000),a tes
t of concentration and ,the quality of information processing).2The
test Fig.1.Black-and-white versions of the stimuli designed for the subliminal prentation.(a)logo A,(b)logo B,(c)mask created from an equal number of parts of both logos.
2This test requires participants to scan rows of consonants for specified consonants
and to transform the into assigned letters via a transformation index.
说英语322 C.Bermeitinger et al./Journal of Experimental Social Psychology45(2009)320–326
was in line with the cover story and was introduced to further focus subjects on the need for concentration.Instructions were given ver-bally and on the test sheets.The test lasted about15min.
Thefifth pha comprid the main part of the experiment. There were four game blocks of2min each.The procedure was the same as in the practice block.Altogether,in each of the four blocks,the word‘‘Konzentration”was prented14times and the subliminal prime was prented24times.Between the blocks, there were consumption breaks of about1min each.During the breaks,participants had the chance to consume the dextro pills. It was emphasized particularly that it was at participants’discre-tion whether,how many,and which pills they cho to consume.
After the last game block and in the sixth experimental pha, participants answered some questions about the game and the dextro brands.They were then informed about the prentation of subliminal logos and asked if they had perceived any aspects of the primes or masks.
This debriefing was followed by the venth pha featuring a direct test of discrimination performance regarding the sublimi-nally prented logos.Each trial was t off by a key press,and then a short quence of the game was shown.Participants were in-structed not to move the manikin but instead to attend to the posi-tion where the subliminal logo was prented.First,a green dot wasflashed for10ms at that position.After a130ms‘‘blank”inter-val,the dot was repeated for a further10ms.Then,after another 130ms,one of the two logos appeared for10ms,followed by the mask
moneyball
for a further10ms(note that the time parameters of logo and mask prentation were exactly the same as in the game blocks).Finally,the two logos were prented next to each other on a white background and subjects had to decide(using the mou)which logo they had just en.This quence was repeated 50times,with random assignment of logos;that is,half of the tri-als contained the logo prented in the game,the other half con-tained the logo that was not prented.
Finally(pha eight),participants were fully debriefed and they were asked to maintain confidentiality concerning the true pur-po of the experiment.The score of each participant was read from the monitor and the subject with the highest score was re-warded the cinema voucher.After the participants had left,the number of consumed pills from each of the two bowls was counted.
Results
Direct test of discrimination performance
For some participants,the parametric signal detection nsitiv-ity measure d0could not be calculated becau their hit rate or fal alarm rate was either zero or one.Therefore,the non-parametric equivalent A0(e Pollack,1970;Pollack&Norman,1964)was cal-culated.A0ranges from one(perfect discrimination)to zero(perfect discrimination,but reverd keys)with A0=.50denoting random respond
ing.On average,A0was.47(SD=0.16),which did not differ significantly from random responding,t(60)=1.34,p=.19.3
Consumption behavior
For the tired and not-tired participants(e footnote4),the mean number of consumed pills associated with logo A and logo B are shown in Table1.First,we calculated the individual difference scores–number of consumed pills of the primed logo minus num-ber of consumed pills of the non-primed logo.Thus,positive values indicate more consumption of the primed product than the non-primed product.The difference values were linearly regresd onto the level of tiredness(fromÀ2=not-tired to2=tired).The analysis revealed a significant positive association between tired-ness and the difference of consumed pills,b=.34,t(60)=2.79, p<.01(e Fig.2)–tired subjects consumed more of the primed product compared to the non-primed product.The constant was significant as well,t(60)=2.11,p<.05.The analysis yielded pre-dicted values with a95%-interval of confidence not including zero for tiredness values aboveÀ0.25(e Fig.2).That is,even for tho participants who were neither especially tired nor especially ‘not-tired’,it can be expected that the consumption of the primed product exceeds the consumption of the non-primed product.
The above regression analysis corresponds to an interaction be-tween type of logo(-primed)and tiredness.Thus, we calculated the simple effects of tiredness parately for primed and non-primed logos.The analys revealed a significant posi-tive association between tiredness and the amount of consumed pills only for the primed logo,b=.30,t(60)=2.44,p<.05,not for the non-primed logo,b=À.04,t<1(e Fig.3).4
Discussion
With the experiment we conceptually replicated thefindings of Karremans et al.(2006).Only participants with a specific need or motivation cho the subliminally prented motivation-related product more often.While Karremans et al.(2006)ud the basic need of thirst as the predictor,we transferred the problem to the motivation for concentration enhancement,which is higher when participants are tired–as demonstrated with an independent sam-ple(e footnote1).Thus,we extended Karremans et al.’sfindings to arrive at a broader understanding of motivational states.
As expected,only tired participants consumed more pills of the primed brand than the non-primed brand;not-tired participants consumed equal amounts of both products.Furthermore,the effect is clearly bad on the additionally consumed primed-brand pills in the tired subsample;there was no di
fference between tired and not-tired participants regarding the consumption of the non-primed product.Thus,only the consumption of the subliminally primed product was influenced–not the consumption of the non-primed product.However,we do not know how the general
3With respect to the individual2(prentation:logo A vs.logo B)Â2(respon: choice of logo A vs.choice of logo B)distribution,three participants had a v2value associated with p-values below.05(all v2>4.02,all p s<.04)and another three participants had a v2value associated with p-values below.10(all v2>2.88,all p s<.09).Excluding the participants from the following analysis did not change the pattern of results.
4To prent the more conventional results of an ANOVA and to exclude interpretations concerning possible material differences,we additionally conducted a repeated measures MANOVA with the factors‘subliminal prime’(logo A vs.logo B),‘tiredness’(-tired),and‘bowl arrangement’(A left and B right vs.B left and A right),and the number of consumed pills from logo A and logo B as the dependent variables.The majority of participants(n=40)had negative tiredness scores.We labeled this subsample‘not-tired’.There were14participants with positive values.The subjects were labeled as‘tired’.Seven subjects had a tiredness score of zero,that is,they considered themlves neither tired nor not-tired.This subsample was labeled‘neither-nor’.Overall,participants had a mean tiredness
of M=À0.60(SE=0.13),which differed significantly from zero,t(60)=4.68,p<.001, and indicates that they were on average rather non-tired.In the MANOVA,there was a significant main effect of‘tiredness’,F(1,46)=4.95,p<.05,g p2=.10;tired partici-pants consumed M=2.31(SE=0.98)more dextro pills than not-tired participants. Further,there was a significant interaction of‘subliminal prime’and‘consumption’, F(1,46)=4.70,p<.05,g p2=.09.Most importantly,the main and interaction effects were qualified by a significant interaction of‘subliminal prime’,‘tiredness’,and ‘consumption’,F(1,46)=9.63,p<.005,g p2=.17.As en from Table1and confirming thefindings from the regression analys,only the tired participants consumed M=1.7(SE=0.56)more pills of the primed product,t(13)=3.07,p<.01.The tendency of the not-tired subjects to consume M=0.25(SE=0.27)more pills of the non-primed(compared to the primed)product was not significant,t<1.No other main or interaction effect reached significance,all F s<2.9,all p s>.09.Most importantly,there was no main effect of the subliminally prented logo,no overall difference between the consumption of products A and B,and no effects including the factor‘bowl arrangement’.
C.Bermeitinger et al./Journal of Experimental Social Psychology45(2009)320–326323
consumption of dextro was affected by the subliminal prime due to the lack of a control group which did not receive any prime. Therefore,it is possible that the prime per led to an increa of d
extro consumption.Nevertheless,for tired participants,the subliminal prime affected the consumption of(additional)dex-tro in a very specific manner,leading only to an increa in primed-brand consumption.This is evidence that the prime af-fected participants’behavior rather specifically.Importantly,we were able to demonstrate the effect of subliminal priming on real consumer behavior(and not only on the intention to consume) in a quite realistic context.
In contrast to Karremans et al.(2006),we checked subjects’individual prime discrimination performance directly.The low rate of participants with above-chance performance in this discrimina-tion task shows that the chon prentation procedure was suc-cessful in preventing conscious awareness of the logos. Additionally,analys of consumption behavior yielded esntially the same results if participants who performed above chance in this direct test were excluded.Hence,the explanation that the ef-fect hinges on consciously available supraliminal information is ru-led out.
The prime stimuli we ud were neutral and non-familiar logos that were designed especially for u in the experiment.That may have incread the chance offinding an effect of the subliminal logo,becau the effect of both subliminal and supraliminal adver-tising is greatest when participants’attitude towards the adver-tid product is ,Brand,1978).Importantly, however,logos were chon to be equally appealing(as indicated by pretest data),they were very sim
ilar(they displayed the same word,they had similar colors,etc.),and each logo rved as the subliminal prime for half of the participants and as the control logo for the other half of the participants.Conquentially,the overall level of consumption of products A vs.B was equivalent.One can therefore conclude that the material had equivalent a priori appeal and that the effect did not depend on a specific logo,but on the actually subliminally prented logo and the individual level of tiredness.Additionally and despite claims to the contrary(Cuperf-ain&Clarke,1985),we can conclude that a subliminal stimulus does not need to have a certain a priori familiarity to be effective in an advertising context.In a similar vein,the prent study dem-onstrates that fairly complex stimuli can elicit subliminal manipu-lation of behavior(which of cour requires that participants’visual system can differentiate between stimuli,cf.Bahrami,Lavie, &Rees,2007).This sheds further light on the question of how com-plex stimuli can actually be for subliminal ,Cooper &Cooper,2002;Greenwald,1992).
The embedding of the subliminal prentation into a computer game ems to be an interesting and potentially momentous vari-ation to earlier studies.Our task was in no way related to the con-sumption product.This constitutes a less artificial context than that ud in most previous studies,which have ud lexical deci-sion tasks and the like.The fact that subjects played a computer
game means that they did not focus their attention on the position where the subliminal stimuli would appear at all times,and also that they were occupied with a more complex task(including,
Table1
Mean number of consumed pills from product A and product B(standard deviation in parenthes)as a function of level of participants’tiredness(not-tired,neither-nor,tired), subliminal prime(logo A vs.logo B)and order of bowl arrangement(A left and B right=AB vs.B left and A right=BA).
Not-tired participants Neither-nor participants Tired participants
Subliminal prime Subliminal prime Subliminal prime
logo A logo B logo A logo B logo A logo B
Consumption of product A
bowl order AB 2.0(2.1) 1.8(1.6)0.5(0.7) 1.0(–)a 4.0(2.0) 1.0(1.0) bowl order BA 1.2(1.6) 1.8(1.3)—b 2.8(2.8) 4.0(3.0) 2.4(1.7) Consumption of product B
bowl order AB 1.8(1.6) 2.1(2.2) 1.5(0.7) 2.0(–)a 2.0(1.0) 3.3(3.2) bowl order BA 2.1(2.0) 1.0(1.2)—b 2.5(1.7) 3.0(1.0) 3.6(2.7)
a There is only one participant in this condition.
b There is no participant in this
condition.
刚果枪击事件Fig.2.Difference of consumed dextro pills(consumed pills of the primed product
Àconsumed pills of the non-primed product)as a function of the level of tiredness
ranging fromÀ2(not-tired)to2(tired)(bold line).Grey lines indicate the95%-
interval of confidence;the arrow indicates the level of tiredness above which the
predicted value of the consumption ,more consumed pills of the
primed product than the non-primed product)is significant(a=
.05).
Fig.3.Consumed dextro pills associated with the subliminally prented logo
(i.e.,the primed logo)and the not prented ,the non-primed logo)as a
function of the level of tiredness ranging fromÀ2(not-tired)to2(tired).
prospecting
324 C.Bermeitinger et al./Journal of Experimental Social Psychology45(2009)320–326
