Subliminal or not? : An appraisal of semantic processing in the near absence of visual awareness

Stimuli that cannot be perceived (i.e., that are subliminal) can still elicit neural responses in an observer, but can such stimuli influence behavior and higher-order cognition? Empirical evidence for such effects has periodically been accepted and rejected over the last six decades. Today, many psychologists seem to consider such effects well-established and recent studies have extended the power of subliminal processing to new limits. In this thesis, I examine whether this shift in zeitgeist is matched by a shift in evidential strength for the phenomenon. This thesis consists of three empirical studies involving more than 250 participants, a simulation study, and a quantitative review. The conclusion based on these efforts is that several methodological, statistical, and theoretical issues remain in studies of subliminal processing. These issues mean that claimed subliminal effects might be caused by occasional or weak percepts (given the experimenters’ own definitions of perception) and that it is still unclear what evidence there is for the cognitive processing of subliminal stimuli. New data are presented suggesting that even in conditions traditionally claimed as “subliminal”, occasional or weak percepts may in fact influence cognitive processing more strongly than do the physical stimuli, possibly leading to reversed priming effects. I also summarize and provide methodological, statistical, and theoretical recommendations that could benefit future research aspiring to provide solid evidence for subliminal cognitive processing.

Implicit and explicit evaluations: a declaration of dependence

This section presents abstracts of three studies on how consumer choices can be influenced by the name letter effect of brands without decision makers being aware of this influence. The first paper examined whether making brand names similar to consumers' names increases the likelihood that consumers will choose the brand. One prediction is that people will prefer and be more likely to choose products or services whose names prominently feature the letters in their own first or last names. The results showed that subjects' preference rankings and evaluations of name letter matching brands were higher than those of non-name letter matching brands. The second paper tested the possibility of using subliminal priming to activate a concept that a persuasive communicator could take advantage of. To examine the idea, two experiments were presented. In the first experiment, participants' level of thirst were manipulated and then subliminally presented them with either thirst-related words or control words. While the manipulations had no effect on participants' self-reported, conscious ratings of thirst, there was a significant interactive effect of the two factors on how much of the drink provided in the taste test was consumed. In a second, follow up experiment, thirsty participants were subliminally presented with either thirst-related words or control words after which they viewed advertisements for two new sports beverages. In conclusion, the research demonstrates that under certain conditions, subliminal printing techniques can enhance persuasion. The third paper hypothesized that the lack of correlations between implicit and explicit evaluations is due to measurement error.

No evidence for subliminal affective priming with emotional facial expression primes

The present study investigated whether facial expressions of emotion presented outside consciousness awareness will elicit evaluative responses as assessed in affective priming. Participants were asked to evaluate pleasant and unpleasant target words that were preceded by masked or unmasked schematic (Experiment 1) or photographic faces (Experiments 1 and 2) with happy or angry expressions. They were either required to perform the target evaluation only or to perform the target evaluation and to name the emotion expressed by the face prime. Prime-target interval was 300 ms in Experiment 1 and 80 ms in Experiment 2. Naming performance confirmed the effectiveness of the masking procedure. Affective priming was evident after unmasked primes in tasks that required naming of the facial expressions for schematic and photographic faces and after unmasked primes in tasks that did not require naming for photographic faces. No affective priming was found after masked primes. The present study failed to provide evidence for affective priming with masked face primes, however, it indicates that voluntary attention to the primes enhances affective priming.

Subliminal Exposure to Empathy Primes: A New Method to Reduce Intergroup Bias?

An abundant literature has demonstrated the benefits of empathy for intergroup relations (e.g., Batson, Chang, Orr, & Rowland, 2002). In addition, empathy has been identified as the mechanism by which various successful prejudice-reduction procedures impact attitudes and behaviour (e.g., Costello & Hodson, 2010). However, standard explicit techniques used in empathy-prejudice research have a number of potential limitations (e.g., resistance; McGregor, 1993). The present project explored an alternative technique, subliminally priming (i.e., outside of awareness) empathy-relevant terms (Study 1), or empathy itself (Study 2). Study 1 compared the effects of exposure to subliminal empathy-relevant primes (e.g., compassion) versus no priming and priming the opposite of empathy (e.g., indifference) on prejudice (i.e., negative attitudes), discrimination (i.e., resource allocation), and helping behaviour (i.e., willingness to empower, directly assist, or expect group change) towards immigrants. Relative to priming the opposite of empathy, participants exposed to primes of empathy-relevant constructs expressed less prejudice and were more willingness to empower immigrants. In addition, the effects were not moderated by individual differences in prejudice-relevant variables (i.e., Disgust Sensitivity, Intergroup Disgust-Sensitivity, Intergroup Anxiety, Social Dominance Orientation, Right-wing Authoritarianism). Study 2 considered a different target category (i.e., Blacks) and attempted to strengthen the effects found by comparing the impact of subliminal empathy primes (relative to no prime or subliminal primes of empathy paired with Blacks) on explicit prejudice towards marginalized groups and Blacks, willingness to help marginalized groups and Blacks, as well as implicit prejudice towards Blacks. In addition, Study 2 considered potential mechanisms for the predicted effects; specifically, general empathy, affective empathy towards Blacks, cognitive empathy towards Blacks, positive mood, and negative mood. Unfortunately, using subliminal empathy primes “backfired”, such that exposure to subliminal empathy primes (relative to no prime) heightened prejudice towards marginalized groups and Blacks, and led to stronger expectations that marginalized groups and Blacks improve their own situation. However, exposure to subliminal primes pairing empathy with Blacks (relative to subliminal empathy primes alone) resulted in less prejudice towards marginalized groups and more willingness to directly assist Blacks, as expected. Interestingly, exposure to subliminal primes of empathy paired with Blacks (vs. empathy alone) resulted in more pro-White bias on the implicit prejudice measure. Study 2 did not find that the potential mediators measured explained the effects found. Overall, the results of the present project do not provide strong support for the use of subliminal empathy primes for improving intergroup relations. In fact, the results of Study 2 suggest that the use of subliminal empathy primes may even backfire. The implications for intergroup research on empathy and priming procedures generally are discussed.

Wie viele Guppys leben in Santiago? Zur Ubiquität des numerischen Priming beim Ankereffekt

Das wohl bekannteste Phänomen der Urteils- und Entscheidungsforschung im Kontext numeri-scher Urteile ist der Ankereffekt. Dieser bezeichnet die Assimilation einer numerischen Schätzung oder Prognose an einen salienten Wert, dem sogenannten Anker, auch unabhängig von dessen inhaltlicher Relevanz. Die Frage nach den Ursachen von Ankereffekten wird bis zum aktuellen Zeitpunkt kontrovers diskutiert. Die Bedeutung eines Erklärungsmodelles, dem sogenannten numerischem Priming, innerhalb dieser Diskussion ist Gegenstand der vorliegenden Arbeit. Im Theorieteil wird zunächst der Ankereffekt, seine inhaltliche Einordnung und seine Relevanz aus theoretischer wie praktischer Sicht diskutiert. Des weiteren werden die gängigen Erklärungsmodelle zum Ankereffekt vorgestellt. Ein Schwerpunkt hierbei liegt auf einer kritischen Auseinandersetzung mit dem Modell der selektiven Zugänglichkeit (Selective Accessibility Model, kurz: SAM), dem wohl prominentesten Modell aus Sicht der momentanen Forschung. Zwei an den Theorieteil anschließende Fragestellungen sind dann der Gegenstand des empirischen Teils der Arbeit. Zum einen soll überprüft werden, ob Ankereffekte im Standardparadigma, wie bisher angenommen, allein auf den Prozessen des SAM basieren oder ob zusätzlich auch numerisches Priming am Zustandekommen des Ankereffektes in diesem Paradigma beteiligt ist. Zum anderen werden Voraussetzungen für das Auftreten von Ankereffekten durch numerisches Priming untersucht, inbesondere die als relevant eingeschätzte Bedeutung der Aufmerksamkeit gegenüber dem Ankerwert. Beide Experimente verwenden neue, im Kontext von Ankereffekten bisher nicht eingesetzte experimentelle Paradigmen. Um die Bedeutung semantischer Prozesse im Zusammenspiel mit numerischen Prozessen zu untersuchen, wird ein so genannter Objektvergleich eingesetzt. Der Stellenwert von Aufmerksamkeit hingegen wird überprüft, in dem die Ankerwerte subliminal, also unterhalb der Wahrnehmungsschwelle, präsentiert werden. Beiden Experimenten ist jeweils eine Voruntersuchung vorangestellt, die notwendige Bedingungen für die entsprechenden Experimente überprüfen. In der abschließenden Diskussion werden die Ergebnisse der beiden Untersuchungen noch einmal zusammengefasst, und deren Implikationen angesichts der bisher vorliegenden Erkenntnisse aus theoretischer wie praktischer Sicht diskutiert. Des weiteren werden mögliche Forschungsfragen und denkbare experimentelle Untersuchungen hierzu skizziert, die an die innerhalb dieser Arbeit vorgelegten Ergebnisse sinnvoll anschließen könnten.

Unconscious Fearful Priming Followed by a Psychosocial Stress Test Results in Higher Cortisol Levels

Human perception of stress includes an automatic pathway that processes subliminal presented stimuli below the threshold of conscious awareness. Subliminal stimuli can therefore activate the physiologic stress system. Unconscious emotional signals were shown to significantly moderate reactions and responses to subsequent stimuli, an effect called 'priming'. We hypothesized that subliminal presentation of a fearful signal during the Stroop task compared with an emotionally neutral one will prime stress reactivity in a subsequently applied psychosocial stress task, thereby yielding a significant increase in salivary cortisol. Half of 36 participants were repeatedly presented either a fearful face or a neutral one. After this, all underwent a psychosocial stress task. The fearful group showed a significant increase in cortisol levels (p = 0.022). This change was not affected by sex, age and body mass index, and it also did not change when taking resting cortisol levels into account. Post-hoc analyses showed that the increase in cortisol in the fearful group started immediately after the psychosocial stress test. Hence, subliminal exposure to a fearful signal in combination with the Stroop and followed by a psychosocial stress test leads to an increase in stress reactivity. Copyright © 2012 John Wiley & Sons, Ltd.

CONSCIÊNCIA E EMOÇÃO: O EFEITO DO PRIMING AFETIVO SUBLIMINAR EM TAREFAS DE ATENÇÃO

Esta tese revisou duas linhas de pesquisa, desenvolvidas nas últimas décadas: o estudo de efeitos de estimulação subliminar priming , e de desencadeamento de reações emocionais por estímulos controlados. Este estudo tem o objetivo de combinar tais linhas para o estudo da consciência com pré-preparo afetivo: efeito de estímulos de conteúdo aversivo, subliminares e supraliminares, sobre a cognição, pela análise do desempenho em tarefa de atenção. Três tarefas experimentais foram realizadas por 35 indivíduos em laboratório de neuropsicologia: a tarefa base onde testamos à detecção de alvo visual simples, e a mesma tarefa de base, porém com estímulos distratores aversivos intercalados, de forma supraliminar ou subliminar (500 ms ou 50 ms de duração), em blocos aleatorizados entre os indivíduos. Calcularam-se índices de detectabilidade e critério de resposta, que serviram para a comparação estatística entre condições (medidas repetidas). Os resultados mostram uma mudança significativa do índice critério , indicando mudança de estratégia na presença de distratores subliminares aversivos. Concluiu-se que a tarefa subliminar fez um efeito destruidor ou devastador na tarefa supraliminar, cometendo menos falso-alarmes protegendo a tarefa supraliminar, tendo um efeito protetor . Os resultados são discutidos no contexto da relevância de influências emocionais sobre o comportamento para a Psicologia da Saúde.

CONSCIÊNCIA E EMOÇÃO: O EFEITO DO PRIMING AFETIVO SUBLIMINAR EM TAREFAS DE ATENÇÃO

Esta tese revisou duas linhas de pesquisa, desenvolvidas nas últimas décadas: o estudo de efeitos de estimulação subliminar priming , e de desencadeamento de reações emocionais por estímulos controlados. Este estudo tem o objetivo de combinar tais linhas para o estudo da consciência com pré-preparo afetivo: efeito de estímulos de conteúdo aversivo, subliminares e supraliminares, sobre a cognição, pela análise do desempenho em tarefa de atenção. Três tarefas experimentais foram realizadas por 35 indivíduos em laboratório de neuropsicologia: a tarefa base onde testamos à detecção de alvo visual simples, e a mesma tarefa de base, porém com estímulos distratores aversivos intercalados, de forma supraliminar ou subliminar (500 ms ou 50 ms de duração), em blocos aleatorizados entre os indivíduos. Calcularam-se índices de detectabilidade e critério de resposta, que serviram para a comparação estatística entre condições (medidas repetidas). Os resultados mostram uma mudança significativa do índice critério , indicando mudança de estratégia na presença de distratores subliminares aversivos. Concluiu-se que a tarefa subliminar fez um efeito destruidor ou devastador na tarefa supraliminar, cometendo menos falso-alarmes protegendo a tarefa supraliminar, tendo um efeito protetor . Os resultados são discutidos no contexto da relevância de influências emocionais sobre o comportamento para a Psicologia da Saúde.

CONSCIÊNCIA E EMOÇÃO: O EFEITO DO PRIMING AFETIVO SUBLIMINAR EM TAREFAS DE ATENÇÃO

Esta tese revisou duas linhas de pesquisa, desenvolvidas nas últimas décadas: o estudo de efeitos de estimulação subliminar priming , e de desencadeamento de reações emocionais por estímulos controlados. Este estudo tem o objetivo de combinar tais linhas para o estudo da consciência com pré-preparo afetivo: efeito de estímulos de conteúdo aversivo, subliminares e supraliminares, sobre a cognição, pela análise do desempenho em tarefa de atenção. Três tarefas experimentais foram realizadas por 35 indivíduos em laboratório de neuropsicologia: a tarefa base onde testamos à detecção de alvo visual simples, e a mesma tarefa de base, porém com estímulos distratores aversivos intercalados, de forma supraliminar ou subliminar (500 ms ou 50 ms de duração), em blocos aleatorizados entre os indivíduos. Calcularam-se índices de detectabilidade e critério de resposta, que serviram para a comparação estatística entre condições (medidas repetidas). Os resultados mostram uma mudança significativa do índice critério , indicando mudança de estratégia na presença de distratores subliminares aversivos. Concluiu-se que a tarefa subliminar fez um efeito destruidor ou devastador na tarefa supraliminar, cometendo menos falso-alarmes protegendo a tarefa supraliminar, tendo um efeito protetor . Os resultados são discutidos no contexto da relevância de influências emocionais sobre o comportamento para a Psicologia da Saúde.

Effects of emotional salience and semantic domain on cross-form priming

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

Subliminal influence on generosity

We experimentally subliminally prime subjects prior to charity donation decisions by showing words that have connotations of pro-social values for a very brief time (17ms). Our main fnding is that, compared to a baseline condition, the pro-social prime increases donations by approximately 10-17 percent among subjects with strong pro-social preferences (universalism values). We find a similar effect when interacting the prime with the Big 5 personality characteristic of agreeableness. We furthermore introduce a novel method for testing for priming, "subliminity". This method reveals that some subjects are capable of recognizing prime words, and the overall results are weaker when we control for this capacity.

Effects of emotional salience and semantic domain on cross-form priming

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

The use of semantic priming as a paradigm for the detection of faking on self-report psychological tests

It is recognised that individuals do not always respond honestly when completing psychological tests. One of the foremost issues for research in this area is the inability to detect individuals attempting to fake. While a number of strategies have been identified in faking, a commonality of these strategies is the latent role of long term memory. Seven studies were conducted in order to examine whether it is possible to detect the activation of faking related cognitions using a lexical decision task. Study 1 found that engagement with experiential processing styles predicted the ability to fake successfully, confirming the role of associative processing styles in faking. After identifying appropriate stimuli for the lexical decision task (Studies 2A and 2B), Studies 3 to 5 examined whether a cognitive state of faking could be primed and subsequently identified, using a lexical decision task. Throughout the course of these studies, the experimental methodology was increasingly refined in an attempt to successfully identify the relevant priming mechanisms. The results were consistent and robust throughout the three priming studies: faking good on a personality test primed positive faking related words in the lexical decision tasks. Faking bad, however, did not result in reliable priming of negative faking related cognitions. To more completely address potential issues with the stimuli and the possible role of affective priming, two additional studies were conducted. Studies 6A and 6B revealed that negative faking related words were more arousing than positive faking related words, and that positive faking related words were more abstract than negative faking related words and neutral words. Study 7 examined whether the priming effects evident in the lexical decision tasks occurred as a result of an unintentional mood induction while faking the psychological tests. Results were equivocal in this regard. This program of research aligned the fields of psychological assessment and cognition to inform the preliminary development and validation of a new tool to detect faking. Consequently, an implicit technique to identify attempts to fake good on a psychological test has been identified, using long established and robust cognitive theories in a novel and innovative way. This approach represents a new paradigm for the detection of individuals responding strategically to psychological testing. With continuing development and validation, this technique may have immense utility in the field of psychological assessment.