Subliminality, consciousness, and temporal shifts in awareness: implications within and beyond the laboratory

In his analysis of subliminal perception research, documented two important (but neglected) phenomena: subchance perception and temporal variability in stimulus availability and accessibility. This Commentary addresses three issues raised by Erdelyi's review: (1) the importance of distinguishing "micro" from "macro" temporal shifts; (2) the need to analyze perception without awareness data at the level of the individual as well as the group; and (3) parallels between the dissociations associated with neuroclinical phenomena (e.g., hemispheric isolation) and those observed in patients with certain forms of personality pathology. Continued integration of laboratory findings with in vivo observations of clinical syndromes will yield a more cohesive and heuristic approach to the study of implicit mental states.     

Goal-discrepant situations prime goal-directed actions if goals are temporarily or chronically accessible

This research tested the hypothesis that perception of goal-discrepant situations automatically (i.e., without conscious intent) facilitates access to representations of instrumental actions if goal representations are mentally accessible. Employing a probe-recognition paradigm, Experiment 1 established that sentences describing situations that are discrepant with the goal of "looking well-groomed" (e.g., having dirty shoes) automatically increased the accessibility of representations of appropriate instrumental actions (e.g., polishing) in comparison to control situations, but only when participants frequently pursued the goal. Experiments 2a and 2b suggest that this effect was due to chronic accessibility of the goal representation and demonstrate that the same effects occur if the accessibility of the goal is temporarily enhanced (by subliminal priming) for people that nonfrequently pursue the goal.     

Likelihood ratio, optimal decision rules, and correct response probabilities in a signal detection theoretic, equal-variance Gaussian model of the observer in the 4IAX paradigm

This article provides a synthetic account of the likelihood ratio, optimal decision rules, and correct response probabilities in a signal detection theoretic model of the observer in the dual-pair comparison, or four-interval AX (4IAX), paradigm. The model assumes a static sampling process, resulting in four, equal-variance normally distributed (i.e., Gaussian) observations on each trial First, a likelihood ratio equation allowing for an arbitrary degree of correlation between observations is provided. Specific solutions for the cases of independent and highly correlated observations are then derived. It is shown that these solutions, and the associated decision rules, correspond to those provided independently in earlier publications. A modified 4IAX paradigm involving, as a standard, an additional stimulus (C) located medially between the A and the B stimuli is also considered. It is shown that the optimal (static, equal-variance, Gaussian) decision model for this paradigm is unaffected by correlation between observations and is equivalent to the standard 4IAX with highly correlated observations. Finally, we consider how, under the considered (static, equal-variance, Gaussian) model, the proportion of correct responses in the different versions of the 4IAX paradigm is related to d', and a solution for the case of independent observations is provided.     

Noncriterial recollection influences metacognitive monitoring and control processes

When retrieving information from memory, temporarily irrelevant material may influence future retrieval endeavours. According to an accessibility account, the amount and intensity of this information can be used to predict the availability of related material. A dual-source paradigm was used to investigate whether information that was not relevant (i.e., noncriterial recollection) to the current memory search would influence metacognitive judgements about a relevant, criterial dimension. In two experiments, participants gave higher feelings-of-knowing judgements for a weakly encoded source dimension when they could subsequently recall the other source dimension later. Furthermore, the influence of the noncriterial information appeared to be driven more so by the subjective state of remembering rather than knowing. Thus, strong memorial information that is temporarily irrelevant influences behaviour.     

Uncertainty about perception and dissociation after compulsive-like staring: Time course of effects

Repeated and compulsive-like checking reduces confidence in memory for the last check. Obsessive-compulsive (OC) patients are not only uncertain about memory, but may also be uncertain about perception, while this perceptual uncertainty may be associated with prolonged visual fixation on the object of uncertainty. It was reported earlier that, among healthy participants, prolonged staring at light bulbs or gas rings induces OC-like uncertainty about perception and feelings of dissociation [van den Hout, M. A., Engelhard, I. M., de Boer, C., du Bois, A., & Dek, E. (2008). Perseverative and compulsive-like staring causes uncertainty about perception. Behaviour Research and Therapy, 46, 1300–1304]. In that study, staring continued for 10 min. For patients, however, staring intervals seem to be considerably shorter. To test the clinical credibility of the paradigm as a model of the maintenance of OC perceptual uncertainty, we investigated whether the effects of staring materialize long before 10 min. Five groups of 16 undergraduates participated: one group did not stare at a gas stove while the others stared for 7.5, 15, 30 or 300 s. In the absence of staring, no pre-to-post increase in dissociation/uncertainty was reported, but after staring it was. The larger part of the observed dissociation/uncertainty after 5 min had occurred within 30 s, and around 50% of this maximal increase was reported between 7.5 and 15 s. Thus, even relatively short intervals of staring induce uncertainty about perception and dissociative experiences. Perseverative looking at objects may be a counter-productive OC strategy, which increases uncertainty about perception and may serve to maintain the disorder.     

Roots, stems, and the universality of lexical representations: evidence from Hebrew

Is the structure of lexical representations universal, or do languages vary in the fundamental ways in which they represent lexical information? Here, we consider a touchstone case: whether Semitic languages require a special morpheme, the consonantal root. In so doing, we explore a well-known constraint on the location of identical consonants that has often been used as motivation for root representations in Semitic languages: Identical consonants frequently occur at the end of putative roots (e.g., skk), but rarely occur in their beginning (e.g., ssk). Although this restriction has traditionally been stated over roots, an alternative account could be stated over stems, a representational entity that is found more widely across the world's languages. To test this possibility, we investigate the acceptability of a single set of roots, manifesting identity initially, finally or not at all (e.g., ssk versus skk versus rmk) across two nominal paradigms: CéCeC (a paradigm in which identical consonants are rare) and CiCúC (a paradigm in which identical consonants are frequent). If Semitic lexical representations consist of roots only, then similar restrictions on consonant co-occurrence should be observed in the two paradigms. Conversely, if speakers store stems, then the restriction on consonant co-occurrence might be modulated by the properties of the nominal paradigm (be it by means of statistical properties or their grammatical sources). Findings from rating and lexical decision experiments with both visual and auditory stimuli support the stem hypothesis: compared to controls (e.g., rmk), forms with identical consonants (e.g., ssk, skk) are less acceptable in the CéCeC than in the CiCúC paradigm. Although our results do not falsify root-based accounts, they strongly raise the possibility that stems could account for the observed restriction on consonantal identity. As such, our results raise fresh challenge to the notion that different languages require distinct sets of representational resources.     

Measuring facial identity and emotion integration using the redundancy gain paradigm

Early theories on face perception posit that invariant (i.e., identity) and changeable (i.e., expression) facial aspects are processed separately. However, many researchers have countered the hypothesis of parallel processes with findings of interactions between identity and emotion perception. The majority of tasks measuring interactions between identity and emotion employ a selective attention design, in which participants are instructed to attend to one dimension (e.g., identity) while the other dimension varies orthogonally (e.g., emotion), but is task irrelevant. Recently, a divided attention design (i.e., the redundancy gain paradigm) in which both identity and emotion are task relevant was employed to assess the interaction between identity and emotion. A redundancy gain is calculated by a drop in reaction time in trials in which a target from both dimensions is present in the stimulus face (e.g., “sad Person A”), compared with trials with only a single target present (e.g., “sad” or “Person A”). Redundancy gains are hypothesized to point to an interactive activation of both dimensions, and as such, could complement designs adopting a selective attention task. The initial aim of the current study was to reproduce the earlier findings with this paradigm on identity and emotion perception (Yankouskaya, Booth, & Humphreys, Attention, Perception, & Psychophysics, 74(8), 1692–1711, 2012), but our study failed to replicate the results. In a series of subtasks, multiple aspects of the design were manipulated separately in our goal to shed light on the factors that influence the redundancy gain effect in faces. A redundancy gain was eventually obtained after controlling for contingencies and stimulus presentation time.     

Repeating a strongly masked stimulus increases priming and awareness

Previous studies [Marcel, A. J. (1983). Conscious and unconscious perception: Experiments on visual masking and word recognition. Cognitive Psychology, 15(2), 197–237; Wentura, D., & Frings, C. (2005). Repeated masked category primes interfere with related exemplars: New evidence for negative semantic priming. Journal of Experimental Psychology: Learning, Memory, and Cognition, 31(1), 108–120] suggested that repeatedly presenting a masked stimulus improves priming without increasing perceptual awareness. However, neural theories of consciousness predict the opposite: Increasing bottom-up strength in such a paradigm should also result in increasing availability to awareness. Here, we tested this prediction by manipulating the number of repetitions of a strongly masked digit. Our results do not replicate the dissociation observed in previous studies and are instead suggestive that repeating an unconscious and attended masked stimulus enables the progressive emergence of perceptual awareness.     

An integrative review of sensory marketing: Engaging the senses to affect perception,judgment and behavior

I define “sensory marketing” as “marketing that engages the consumers' senses and affects their perception, judgment and behavior.” From a managerial perspective, sensory marketing can be used to create subconscious triggers that characterize consumer perceptions of abstract notions of the product (e.g., its sophistication or quality). Given the gamut of explicit marketing appeals made to consumers every day, subconscious triggers which appeal to the basic senses may be a more efficient way to engage consumers. Also, these sensory triggers may result in consumers' self-generation of (desirable) brand attributes, rather than those verbally provided by the advertiser. The understanding of these sensory triggers implies an understanding of sensation and perception as it applies to consumer behavior—this is the research perspective of sensory marketing. This review article presents an overview of research on sensory perception. The review also points out areas where little research has been done, so that each additional paper has a greater chance of making a bigger difference and sparking further research. It is quite apparent from the review that there still remains tremendous need for research within the domain of sensory marketing—research that can be very impactful.     

Somatosensory processing and schizophrenia liability: proprioception, exteroceptive sensitivity, and graphesthesia performance in the biological relatives of schizophrenia patients

In the present study, the authors examined somatosensory processing in 30 biological relatives of persons with schizophrenia (hereafter called "schizophrenia relatives"), 30 biological relatives of persons with bipolar affective disorder (psychiatric family control subjects), and 30 healthy control subjects with no family history of psychopathology. All 3 groups completed a weight discrimination task, a 2-point discrimination task, and a complex cognitive somatosensory task (i.e., graphesthesia). The schizophrenia relatives performed significantly worse on all 3 somatosensory tasks compared with both the healthy control subjects and the bipolar relatives. The healthy control subjects and psychiatric family control subjects showed no significant differences on any of the somatosensory tasks. Within the weight discrimination and 2-point discrimination tasks, schizophrenia relatives showed group differences on the d' index, the measure of sensitivity, whereas all 3 groups did not differ on lnbeta, the measure of response bias, suggesting a genuine difference in weight and touch sensitivity. The d' value of the weight discrimination task was significantly associated with both the cognitive-perceptual factor and negative symptom factor of the clinical questionnaire (e.g., Schizotypal Personality Questionnaire; SPQ), whereas the 2-point discrimination d' value and graphesthesia scores were significantly associated only with the cognitive-perceptual factor of the SPQ. Implications for the possible relation between somatosensory task performance and schizophrenia liability are discussed.     

Resource loss,resource gain,PTSD, and dissociation among Ethiopian immigrants in Israel

The aim of this study was to examine the loss and gain of resources, posttraumatic stress disorder (PTSD) and dissociation among Jewish Ethiopian immigrants in Israel following exposure to stressful events occurring pre‐, peri‐, and post‐migration. Resources are defined as objects (e.g., housing), conditions (e.g., employment), personal (e.g., self‐esteem), or energy (e.g., culture). A random sample (N = 478) of three waves of immigrants participated in the research (N1 = 165; N2 = 169; N3 = 144). The data were collected in 2001. Age, loss and gain of resources, traumatic events peri‐migration, post‐migration difficulties, posttraumatic symptoms, and dissociation were assessed. The relationships between the variables were assessed with multiple hierarchical regressions predicting PTSD and dissociation with gain and loss of resources, over and above age, immigration wave, and trauma. A significant relationship was found between PTSD symptoms and loss of self‐esteem resources (r = 0.17 p < 0.001), while dissociation was positively associated with gain of housing resources (r = 0.20, p < 0.001). Both PTSD and dissociation were predicted by younger age. The findings are discussed in light of the conservation of resources (COR) theory (Hobfoll, 1988 ), of resource loss and gain among Ethiopian immigrants.     

Perception of ensemble statistics requires attention

To overcome inherent limitations in perceptual bandwidth, many aspects of the visual world are represented as summary statistics (e.g., average size, orientation, or density of objects). Here, we investigated the relationship between summary (ensemble) statistics and visual attention. Recently, it was claimed that one ensemble statistic in particular, color diversity, can be perceived without focal attention. However, a broader debate exists over the attentional requirements of conscious perception, and it is possible that some form of attention is necessary for ensemble perception. To test this idea, we employed a modified inattentional blindness paradigm and found that multiple types of summary statistics (color and size) often go unnoticed without attention. In addition, we found attentional costs in dual-task situations, further implicating a role for attention in statistical perception. Overall, we conclude that while visual ensembles may be processed efficiently, some amount of attention is necessary for conscious perception of ensemble statistics.     

Posttraumatic stress disorder in a national sample of female and male Vietnam veterans: risk factors, war-zone stressors, and resilience-recovery variables

Relationships among pretrauma risk factors (e.g., family instability, childhood antisocial behavior), war-zone stressors (e.g., combat, perceived threat), posttrauma resilience-recovery variables (e.g., hardiness, social support), and posttraumatic stress disorder (PTSD) symptom severity were examined. Data from a national sample of 432 female and 1,200 male veterans were analyzed using structural equation modeling. For both genders, direct links to PTSD from pretrauma, war-zone, and posttrauma variable categories were found; several direct associations between pretrauma and posttrauma variables were documented. Although war-zone stressors appeared preeminent for PTSD in men, posttrauma resilience-recovery variables were more salient for women. Researchers, policymakers, and clinicians are urged to take a broad view on trauma and its sequelae, especially regarding possible multiple exposures over time and the depletion and availability of important resources.     

Changes in boundary extension effect during spatial confinement

Changes in perception during space missions are usually attributed to microgravity. However, additional factors, such as spatial confinement, may contribute to changes in perception. We tested changes in scene perception using a boundary extension (BE) paradigm during a 105-day Earth-based space-simulation study. In addition to the close-up/wide-angle views used in BE, we presented two types of scenes based on the distance from the observer (proximal/distant scenes). In crew members (n = 6), we found that BE partly increased over time, but the size of BE error did not change in the control group (n = 22). We propose that this effect is caused by an increasing BE effect in stimuli that depict distant scenes and is related to spatial confinement. The results might be important for other situations of spatial confinement with restricted visual depth (e.g., submarine crew, patients confined to a bed). Generally, we found a larger BE effect in proximal scenes compared with the distant scenes. We also demonstrated that with no feedback, subjects preserve the level of the BE effect during repeated measurements.     

Dissociation of processing time and awareness by the inattentional blindness paradigm

Consciousness researchers are interested in distinguishing between mental activity that occurs with and without awareness (i.e., explicit versus implicit processes). The inattentional blindness (IB) paradigm is an excellent tool for this question because it permits the independent manipulation of processing time and awareness. In the present study, we show that implicit texture segregation can occur during inattentional blindness, provided that the texture is exposed for a sufficient duration. In contrast, a Simon effect does not occur during inattentional blindness, even with similar exposure duration of the critical stimulus. This reveals a dissociation between processing time and awareness, consistent with the possibility of separate processing streams for explicit and implicit visual perception.     

The effect of research method type on stereotypes’ content: A brief research report

Stereotype Content Model (SCM) emphasizes the content rather than the underlying processes of the stereotypes and the content might be influenced by several cultural dimensions (e.g., individualism vs. collectivism). The main dimensions of SCM—namely warmth and competence—underlying various contents are assumed to be universal. However, from a cognitive science paradigm, we argue that different research methods (i.e., data collections and data analysis) might also yield different stereotype contents that might impact the universality versus specificity problem in the SCM. Indeed, using a sample from a collectivistic country (i.e., Romania), we found that using different methods in data collection (i.e., unstructured vs. semi-structured vs. structured interview) and different methods of data analysis (i.e., availability vs. accessibility scores) might be an important research strategy to counter artefacts and confusions in the universality versus specificity problem related to the SCM. Theoretical and practical implications are discussed.     

Language and the perception of emotion

Three studies assessed the relationship between language and the perception of emotion. The authors predicted and found that the accessibility of emotion words influenced participants' speed or accuracy in perceiving facial behaviors depicting emotion. Specifically, emotion words were either primed or temporarily made less accessible using a semantic satiation procedure. In Studies 1 and 2, participants were slower to categorize facial behaviors depicting emotion (i.e., a face depicting anger) after an emotion word (e.g., "anger") was satiated. In Study 3, participants were less accurate to categorize facial behaviors depicting emotion after an emotion word was satiated. The implications of these findings for a linguistically relative view of emotion perception are discussed.     

Using direct and indirect measures to study perception without awareness

Many studies directed at demonstrating perception without awareness have relied on the dissociation paradigm. Although the logic underlying this paradigm is relatively straightforward, definitive results have been elusive in the absence of any general consensus as to what constitutes an adequate measure of awareness. We propose an alternative approach that involves comparisons of the relative sensitivity of comparable direct and indirect indexes of perception. The only assumption required by the proposed approach is that the sensitivity of direct discriminations to relevant conscious information is greater than or equal to the sensitivity of comparable indirect discriminations. The proposed approach is illustrated through an evaluation of Avant and Thieman’s (1985) recent claim that an indirect measure of perception based on judgments of apparent visual duration provides a more sensitive indicator of perception than does a direct measure based on forced-choice recognition. Contrary to this claim, when direct and indirect indexes are measured under comparable conditions, an indirect measure based on judgments of perceived duration provides a less sensitive index of perceptual processing than do comparable direct measures. The proposed approach provides a general conceptual/methodological framework for using the dissociation paradigm in studies directed at establishing unconscious processes.     

Priming the holiday spirit: Persistent activation due to extraexperimental experiences

The concept of activation is a critical component of many models of cognition. A key characteristic of activation is that recent experience with a concept or stimulus increases the accessibility of the corresponding representation. The extent to which increases in accessibility occur as a result of experiences outside of laboratory settings has not been extensively explored. In the present study, we presented lexical stimuli associated with different holidays and festivities over the course of a year in a lexical decision task. When stimulus meaning and time of testing were congruent (e.g., leprechaun in March), response times were faster and accuracy greater than when meaning and time of test were incongruent (e.g., leprechaun in November). Congruency also benefited performance on a surprise free recall task of the items presented earlier in the lexical decision task. The discussion focuses on potential theoretical accounts of this heightened accessibility of time-of-the-year-relevant concepts.