A lateralized alpha-band marker of the interference of exogenous attention over endogenous attention.

Current theories of attention differentiate exogenous from endogenous orienting of visuospatial attention. While both forms of attention orienting engage different functional systems, endogenous and exogenous attention are thought to share resources, as shown by empirical evidence of their functional interactions. The present study aims to uncover the neurobiological basis of how salient events that drive exogenous attention disrupts endogenous attention processes. We hypothesize that interference from exogenous attention over endogenous attention involves alpha-band activity, a neural marker of visuospatial attention. To test this hypothesis, we contrast the effects of endogenous attention across two experimental tasks while we recorded electroencephalography (n = 32, both sexes): a single cueing task where endogenous attention is engaged in isolation, and a double cueing task where endogenous attention is concurrently engaged with exogenous attention. Our results confirm that the concurrent engagement of exogenous attention interferes with endogenous attention processes. We also found that changes in alpha-band activity mediate the relationship between endogenous attention and its effect on task performance, and that the interference of exogenous attention on endogenous attention occurs via the moderation of this indirect effect. Altogether, our results substantiate a model of attention, whereby endogenous and exogenous attentional processes involve the same neurophysiological resources. SIGNIFICANCE STATEMENT: Scientists differentiate top-down from bottom-up visuospatial attention processes. While bottom-up attention is rapidly engaged by emerging demands from the environment, top-down attention in contrast reflects slow voluntary shifts of spatial attention. Several lines of research substantiate the idea that top-down and bottom-up attentional processes involve distinct functional systems. An increasing number of studies, however, argue that both attention systems share brain processing resources. The current study examines how salient visual events that engage bottom-up processes interfere with top-down attentional processes. Using neurophysiological recordings and multivariate pattern classification techniques, the authors show that these patterns of interference occur within the alpha-band of neural activity (8-12 Hz), which implies that bottom-up and top-down attention processes share this narrow-band frequency brain resource. The results further demonstrate that patterns of alpha-band activity explains, in part, the interference between top-down and bottom-up attention at the behavioral level.

Differential and Overlapping Effects between Exogenous and Endogenous Attention Shape Perceptual Facilitation during Visual Processing.

Visuospatial attention is not a monolithic process and can be divided into different functional systems. In this framework, exogenous attention reflects the involuntary orienting of attention resources following a salient event, whereas endogenous attention corresponds to voluntary orienting based on the goals and intentions of individuals. Previous work shows that these attention processes map onto distinct functional systems, yet evidence suggests that they are not fully independent. In the current work, we investigated the differential and overlapping effects of exogenous and endogenous attention on visual processing. We combined spatial cueing of visuospatial attention, EEG, and multivariate pattern analysis to examine where and when the effects of exogenous and endogenous attention were maximally different and maximally similar. Critically, multivariate pattern analysis provided new insights by examining whether classifiers trained to decode the cueing effect for one attention process (e.g., exogenous attention) can successfully decode the cueing effect for the other attention process (e.g., endogenous attention). These analyses uncovered differential and overlapping effects between exogenous and endogenous attention. Next, we combined principal component analyses, single-trial ERPs, and mediation analysis to determine whether these effects facilitate perception, as indexed by the behavioral spatial cueing effects of exogenous and endogenous attention. This approach revealed that three EEG components shape the cueing effects of exogenous and endogenous attention at various times after target onset. Altogether, our study provides a comprehensive account about how overlapping and differential processes of endogenous and exogenous relate to perceptual facilitation in the context of visuospatial attention.

Class imbalance should not throw you off balance: Choosing the right classifiers and performance metrics for brain decoding with imbalanced data.

Machine learning (ML) is increasingly used in cognitive, computational and clinical neuroscience. The reliable and efficient application of ML requires a sound understanding of its subtleties and limitations. Training ML models on datasets with imbalanced classes is a particularly common problem, and it can have severe consequences if not adequately addressed. With the neuroscience ML user in mind, this paper provides a didactic assessment of the class imbalance problem and illustrates its impact through systematic manipulation of data imbalance ratios in (i) simulated data and (ii) brain data recorded with electroencephalography (EEG), magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI). Our results illustrate how the widely-used Accuracy (Acc) metric, which measures the overall proportion of successful predictions, yields misleadingly high performances, as class imbalance increases. Because Acc weights the per-class ratios of correct predictions proportionally to class size, it largely disregards the performance on the minority class. A binary classification model that learns to systematically vote for the majority class will yield an artificially high decoding accuracy that directly reflects the imbalance between the two classes, rather than any genuine generalizable ability to discriminate between them. We show that other evaluation metrics such as the Area Under the Curve (AUC) of the Receiver Operating Characteristic (ROC), and the less common Balanced Accuracy (BAcc) metric - defined as the arithmetic mean between sensitivity and specificity, provide more reliable performance evaluations for imbalanced data. Our findings also highlight the robustness of Random Forest (RF), and the benefits of using stratified cross-validation and hyperprameter optimization to tackle data imbalance. Critically, for neuroscience ML applications that seek to minimize overall classification error, we recommend the routine use of BAcc, which in the specific case of balanced data is equivalent to using standard Acc, and readily extends to multi-class settings. Importantly, we present a list of recommendations for dealing with imbalanced data, as well as open-source code to allow the neuroscience community to replicate and extend our observations and explore alternative approaches to coping with imbalanced data.

Effects of interocular grouping demands on binocular rivalry.

Binocular rivalry (BR) is a visual phenomenon in which perception alternates between two non-fusible images presented to each eye. Transition periods between dominant and suppressed images are marked by mixed percepts, where participants report fragments of each image being dynamically perceived. Interestingly, BR remains robust even when typical images are subdivided and presented in complementary patches to each eye, a phenomenon termed interocular grouping (IOG). The objective of the present study was to determine if increasing grouping demand in the context of BR changes the perceptual experience of rivalry. In 48 subjects with normal vision, mean dominant and mixed percept durations were recorded for classic BR and IOG conditions with increasing grouping demands from two, four, and six patches. We found that, as grouping demands increased, the duration of mixed periods increased. Indeed, durations of dominant and mixed percepts, as well as percentage of time spent in dominant or mixed state, differed significantly across conditions. However, durations of global dominant percepts remained relatively stable and saturated at about 1.5 seconds, despite the exponential increase in possible mixed combinations. Evidence shows that this saturation followed a nonlinear trend. The data also indicate that grouping across the vertical meridian is slightly more stable than for the horizontal meridian. Finally, individual differences in speed of alternation identified during BR were maintained in all interocular grouping conditions. These results provide new information about binocular visual spatial integration and will be useful for future studies of the underlying neural substrates and models of binocular vision.

Glial Cell-Derived Neurotrophic Factor Induces Enteric Neurogenesis and Improves Colon Structure and Function in Mouse Models of Hirschsprung Disease.

BACKGROUND & AIMS: Hirschsprung disease (HSCR) is a life-threatening birth defect in which the distal colon is devoid of enteric neural ganglia. HSCR is treated by surgical removal of aganglionic bowel, but many children continue to have severe problems after surgery. We studied whether administration of glial cell derived neurotrophic factor (GDNF) induces enteric nervous system regeneration in mouse models of HSCR. METHODS: We performed studies with four mouse models of HSCR: Holstein (HolTg/Tg, a model for trisomy 21-associated HSCR), TashT (TashTTg/Tg, a model for male-biased HSCR), Piebald-lethal (Ednrbs-l//s-l, a model for EDNRB mutation-associated HSCR), and Ret9/- (with aganglionosis induced by mycophenolate). Mice were given rectal enemas containing GDNF or saline (control) from postnatal days 4 through 8. We measured survival times of mice, and colon tissues were analyzed by histology, immunofluorescence, and immunoblots. Neural ganglia regeneration and structure, bowel motility, epithelial permeability, muscle thickness, and neutrophil infiltration were studied in colon tissues and in mice. Stool samples were collected, and microbiomes were analyzed by 16S rRNA gene sequencing. Time-lapse imaging and genetic cell-lineage tracing were used to identify a source of GDNF-targeted neural progenitors. Human aganglionic colon explants from children with HSCR were cultured with GDNF and evaluated for neurogenesis. RESULTS: GDNF significantly prolonged mean survival times of HolTg/Tg mice, Ednrbs-l//s-l mice, and male TashTTg/Tg mice, compared with control mice, but not Ret9/- mice (which had mycophenolate toxicity). Mice given GDNF developed neurons and glia in distal bowel tissues that were aganglionic in control mice, had a significant increase in colon motility, and had significant decreases in epithelial permeability, muscle thickness, and neutrophil density. We observed dysbiosis in fecal samples from HolTg/Tg mice compared with feces from wild-type mice; fecal microbiomes of mice given GDNF were similar to those of wild-type mice except for Bacteroides. Exogenous luminal GDNF penetrated aganglionic colon epithelium of HolTg/Tg mice, inducing production of endogenous GDNF, and new enteric neurons and glia appeared to arise from Schwann cells within extrinsic nerves. GDNF application to cultured explants of human aganglionic bowel induced proliferation of Schwann cells and formation of new neurons. CONCLUSIONS: GDNF prolonged survival, induced enteric neurogenesis, and improved colon structure and function in 3 mouse models of HSCR. Application of GDNF to cultured explants of aganglionic bowel from children with HSCR induced proliferation of Schwann cells and formation of new neurons. GDNF might be developed for treatment of HSCR.

Difficult Turned Easy: Suggestion Renders a Challenging Visual Task Simple.

Suggestions can cause some individuals to miss or disregard existing visual stimuli, but can they infuse sensory input with nonexistent information? Although several prominent theories of hypnotic suggestion propose that mental imagery can change our perceptual experience, data to support this stance remain sparse. The present study addressed this lacuna, showing how suggesting the presence of physically absent, yet critical, visual information transforms an otherwise difficult task into an easy one. Here, we show how adult participants who are highly susceptible to hypnotic suggestion successfully hallucinated visual occluders on top of moving objects. Our findings support the idea that, at least in some people, suggestions can add perceptual information to sensory input. This observation adds meaningful weight to theoretical, clinical, and applied aspects of the brain and psychological sciences.

Simulated thought insertion: Influencing the sense of agency using deception and magic.

In order to study the feeling of control over decisions, we told 60 participants that a neuroimaging machine could read and influence their thoughts. While inside a mock brain scanner, participants chose arbitrary numbers in two similar tasks. In the Mind-Reading Task, the scanner appeared to guess the participants' numbers; in the Mind-Influencing Task, it appeared to influence their choice of numbers. We predicted that participants would feel less voluntary control over their decisions when they believed that the scanner was influencing their choices. As predicted, participants felt less control and made slower decisions in the Mind-Influencing Task compared to the Mind-Reading Task. A second study replicated these findings. Participants' experience of the ostensible influence varied, with some reporting an unknown source directing them towards specific numbers. This simulated thought insertion paradigm can therefore influence feelings of voluntary control and may help model symptoms of mental disorders.

Hypnosis and imaging of the living human brain.

Over more than two decades, studies using imaging techniques of the living human brain have begun to explore the neural correlates of hypnosis. The collective findings provide a gripping, albeit preliminary, account of the underlying neurobiological mechanisms involved in hypnotic phenomena. While substantial advances lend support to different hypotheses pertaining to hypnotic modulation of attention, control, and monitoring processes, the complex interactions among the many mediating variables largely hinder our ability to isolate robust commonalities across studies. The present account presents a critical integrative synthesis of neuroimaging studies targeting hypnosis as a function of suggestion. Specifically, hypnotic induction without task-specific suggestion is examined, as well as suggestions concerning sensation and perception, memory, and ideomotor response. The importance of carefully designed experiments is highlighted to better tease apart the neural correlates that subserve hypnotic phenomena. Moreover, converging findings intimate that hypnotic suggestions seem to induce specific neural patterns. These observations propose that suggestions may have the ability to target focal brain networks. Drawing on evidence spanning several technological modalities, neuroimaging studies of hypnosis pave the road to a more scientific understanding of a dramatic, yet largely evasive, domain of human behavior.

Cultivating Comfort: Examining Participant Satisfaction with Hypnotic Communication Training in Pain Management.

Context: One in four Canadians experiences chronic pain, yet insufficient services and restrictions surrounding prevailing treatments result in inadequate management and significant negative consequences for these individuals. Previous work indicates that hypnotic communication represents a promising complementary treatment; however, training protocols for healthcare professionals are underdeveloped and understudied. Aim: To evaluate the level of satisfaction for a training program on hypnotic communication in pain management clinics. Design: Qualitative study. Methods: Six health professionals who first completed the hypnotic communication training participated in 30 minutes virtual semi-structured interviews. These testimonials allowed them to elaborate on their user experience and potential areas for improvement. Thematic analysis using qualitative data management software NVIVO was conducted on the interview data. Results: Two themes emerged from the interviews. 1) Satisfaction: Participants expressed satisfaction on various structural aspects of the training, including the provided materials, atmosphere, training structure, presentation modalities, practical workshops, acquired knowledge, trainer quality, and training duration. 2) Areas for Improvement: Five main improvement suggestions were identified (providing more material; more practical workshops, more concrete and adapted; testimonials from former patients; follow-up training meeting; and continuing education). Implications for the Profession and/or Patient Care and Conclusion: The results improved the training program to help minimized inherent biases related to this technique, cut associated costs, and identify reasons that would explain its underutilization among medical professionals in Quebec. Our work highlights that healthcare professionals in chronic pain management clinics (eg, respiratory therapists, nurses) can incorporate this simple hypnotic communication technique into their usual care and contribute to the well-being of patients. Impact: This study aimed to address the lack of training protocols for healthcare professionals, that are underdeveloped and understudied. The main findings on participant' satisfaction and the areas of improvement for the training will help the refinement of the training to better suit healthcare professional's needs in hospitals and chronic pain facilities.

Make me more comfortable: effects of a hypnosis session on pain perception in chronic pain patients.

Introduction: Approximately one-quarter of Canadians experience chronic pain, a debilitating condition often necessitating opioid use, which raises concerns regarding dependency and overdose risks. As an alternative, we developed the HYlaDO program (Hypnose de la Douleur, hypnosis of Pain in French), a novel self-hypnosis approach for chronic pain management. The development of this program followed the ORBIT model, a comprehensive framework for designing interventions encompassing several phases ranging from design to efficacy assessment. Methods: In the present work, we conducted a preliminary evaluation of the HYlaDO program with 21 participants (18 of the 21 patients were included in the analysis). The primary objective was to determine one session of the program's effectiveness in altering pain, anxiety and relaxation via pre-post analysis. The secondary goal was to examine the long-term effects across the same measures, in addition to the overall quality of life. Results: The results highlight the benefits of our approach, while participants reported short-term significant pain reduction, decreased anxiety, and increased relaxation. Additionally, preliminary trends suggest improvements in physical activity and quality of life metrics. Discussion: These positive outcomes highlight HYlaDO's potential as an alternative to opioid therapy for chronic pain. Encouraged by these results, we aim to extend our research to a broader and more diverse cohort, paving the way for comprehensive randomized controlled trials. This expansion will further validate HYlaDO's efficacy and its role in transforming chronic pain management.

Practicing self-hypnosis to reduce chronic pain: A qualitative exploratory study of HYlaDO.

Background: Nearly a quarter of Canada's population suffers from chronic pain, a long-lasting medical condition marked by physical pain and psychological suffering. Opioids are the primary treatment for pain management in this condition; yet, this approach involves several undesirable side effects. In contrast to this established approach, non-pharmacological interventions, such as medical hypnosis, represent an efficient alternative for pain management in the context of chronic pain. HYlaDO is a self-hypnosis program designed to improve pain management for people with chronic pain. Purpose: This research aimed to evaluate the HYlaDO program based on the proof-of-concept level of the ORBIT model and investigated participants' subjective experience. Research design: Qualitative study. Study sample: Seventeen participants with chronic pain took part in this study. Data collection: We conducted individual semi-structured interviews with patients who had participated in HYlaDO to identify the three targets of desired change: pain, anxiety and autonomy in self-hypnosis practice. Results: Thematic analysis revealed that the practice of hetero-hypnosis and self-hypnosis decreased (i) pain and (ii) anxiety. Also, it (iii) indicated the development of an independent and beneficial self-hypnosis practice by having integrated the techniques taught. Conclusion: These results confirm that the established targets were reached and support further development, implementation and scaling up of this program. Consequently, we believe it is justified to move to the next step of program development.

The Rubber Hand Illusion: Top-down attention modulates embodiment.

The Rubber Hand Illusion (RHI) creates distortions of body ownership through multimodal integration of somatosensory and visual inputs. This illusion largely rests on bottom-up (automatic multisensory and perceptual integration) mechanisms. However, the relative contribution from top-down factors, such as controlled processes involving attentional regulation, remains unclear. Following previous work that highlights the putative influence of higher-order cognition in the RHI, we aimed to further examine how modulations of working memory load and task instructions-two conditions engaging top-down cognitive processes-influence the experience of the RHI, as indexed by a number of psychometric dimensions. Relying on exploratory factor analysis for assessing this phenomenology within the RHI, our results confirm the influence of higher-order, top-down mental processes. Whereas task instruction strongly modulated embodiment of the rubber hand, cognitive load altered the affective dimension of the RHI. Our findings corroborate that top-down processes shape the phenomenology of the RHI and herald new ways to improve experimental control over the RHI.

Hypnosis and music interventions for anxiety, pain, sleep and well-being in palliative care: systematic review and meta-analysis.

BACKGROUND: Maintaining quality of life is a primary goal of palliative care (PC). Complementary interventions can help meet the needs of patients at the end of life. OBJECTIVES: This meta-analysis aims to (1) evaluate the feasibility, acceptability and fidelity of music and hypnosis interventions designed for patients in PC and (2) evaluate the impact of these interventions on pain, anxiety, sleep and well-being. METHODS: Relevant studies were sourced from major databases. We selected both randomised controlled trials (RCTs) and studies relying on pre-post design with details of the intervention(s). RESULTS: Four RCT and seven non-randomised pre-post studies met the inclusion criteria. Overall, the feasibility and acceptability of the interventions reached an adequate level of satisfaction. However, only three studies reported using a written protocol. The meta-analysis of RCT indicated a significant decrease in pain with an effect size of -0.42, p=0.003. The small number of RCT studies did not allow us to quantify the effects for other variables. Analyses of data from pre-post designs indicated a favourable outcome for pain, anxiety, sleep and well-being. CONCLUSION: Despite the limited number of studies included in our meta-analysis, hypnosis and music intervention in the context of PC shows promising results in terms of feasibility and acceptability, as well as improvements on pain, anxiety, sleep and well-being. The available studies are insufficient to compare the efficacy across interventions and assess the potential benefits of their combinations. These results underscore the importance of further research on well-described complementary interventions relying on hypnosis and music. PROSPERO REGISTRATION NUMBER: CRD-42021236610.

Investigating how the modularity of visuospatial attention shapes conscious perception using type I and type II signal detection theory.

Attention abilities rest on the coordinated interplay of multiple components. One consequence to this multifaceted account is that selection processes likely intersect with perception at various junctures. Drawing from this overarching view, the current research examines how different forms of visuospatial attention influence various aspects of conscious perception, including signal detection, signal discrimination, visual awareness, and metacognition. In this effort, we combined a double spatial cueing approach, where stimulus- and goal-driven orienting were concurrently engaged via separate cues, with Type I and Type II signal detection theoretic frameworks through five experiments. Consistent with the modular view of visuospatial attention, our comprehensive assessment reveals that stimulus- and goal-driven orienting operate independently of each other for increasing perceptual sensitivity and reducing the decision bound. Conversely, however, our study shows that both forms of orienting hardly influence visual awareness and metacognition once perceptual sensitivity is accounted for. Our results therefore undermine the idea that attention directly interfaces with subjective aspects of perception. Instead, our findings submit a general framework whereby these attention modules indirectly impact visual awareness and metacognition by increasing perceptual evidence and decreasing the decision bound. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Gut microbiota-mediated Gene-Environment interaction in the TashT mouse model of Hirschsprung disease.

Based on the bilateral relationship between the gut microbiota and formation/function of the enteric nervous system (ENS), we sought to determine whether antibiotics-induced dysbiosis might impact the expressivity of genetically-induced ENS abnormalities. To address this, we took advantage of the TashT mouse model of Hirschsprung disease, in which colonic aganglionosis and hypoganglionosis are both much more severe in males. These defects result into two male-biased colon motility phenotypes: either megacolon that is lethal around weaning age or chronic constipation in adults, the latter being also associated with an increased proportion of nitrergic neurons in the distal ENS. Induction of dysbiosis using a cocktail of broad-spectrum antibiotics specifically impacted the colonic ENS of TashTTg/Tg mice in a stage-dependent manner. It further decreased the neuronal density at post-weaning age and differentially modulated the otherwise increased proportion of nitrergic neurons, which appeared normalized around weaning age and further increased at post-weaning age. These changes delayed the development of megacolon around weaning age but led to premature onset of severe constipation later on. Finally, local inhibition of nitric oxide signaling improved motility and prevented death by megacolon. We thus conclude that exposure to antibiotics can negatively influence the expressivity of a genetically-induced enteric neuropathy.

Hypnosis in palliative care: from clinical insights to the science of self-regulation.

Palliative care spans a wide-ranging spectrum: from pain-management to spiritual support. As the demand for end-of-life care increases, so does the demand for innovative, effective, interventions. Mind-body techniques seem especially advantageous in a palliative context. Here we show that hypnosis serves an excellent adjunct therapy in palliative care to boost the efficacy of standard treatments. With the overarching goal of bridging clinical and scientific insights, we outline how five core principles of hypnosis can benefit the diverse needs of palliative care.

Brain correlates of hypnosis: A systematic review and meta-analytic exploration.

Imaging of the living human brain elucidates the neural dynamics of hypnosis; however, few reliable brain patterns emerge across studies. Here, we methodically assess neuroimaging assays of hypnosis to uncover common neural configurations using a twofold approach. First, we systematically review research on the neural correlates of hypnotic phenomena; then, we meta-analyze these collective data seeking specific activation and deactivation patterns that typify hypnosis. Anchored around the role of top-down control processes, our comprehensive examination focuses on the involvement of intrinsic brain networks known to support cognitive control and self-referential cognition, including the executive, salience, and default networks. We discuss how these neural dynamics may relate to contemporary theories of hypnosis and show that hypnosis correlates with activation of the lingual gyrus-a brain region involved in higher-order visual processing and mental imagery. Our findings help to better understand the neurobiological substrates comprising the appellation hypnosis.

Combining attention: a novel way of conceptualizing the links between attention, sensory processing, and behavior.

Many everyday behaviors appear to require both the interpretation of incoming sensory information and the maintenance of a current task goal. This intuitive notion suggests that combining attentional control processes might reflect a fundamentally novel way in which attention supports complex behavior. Using an established paradigm, here we show that joint recruitment in multiple attention control systems leads to corresponding combined increases in behavior and underlying sensory processing of attended targets. Moreover, our data also revealed that the nature of the combined effect depends on a flexible allocation of attentional resources to individual component processes, which change dynamically as a function of task demands. Together, these data provide a new conceptual framework for characterizing the role of attention in behavior and suggest important extensions to the prevailing theories of attention.

Composition of the Spruce Budworm (Choristoneura fumiferana) Midgut Microbiota as Affected by Rearing Conditions.

The eastern spruce budworm (Choristoneura fumiferana) is one of the most destructive forest insect pests in Canada. Little is known about its intestinal microbiota, which could play a role in digestion, immune protection, communication and/or development. The present study was designed to provide a first characterization of the effects of rearing conditions on the taxonomic diversity and structure of the C. fumiferana midgut microbiota, using a culture-independent approach. Three diets and insect sources were examined: larvae from a laboratory colony reared on a synthetic diet and field-collected larvae reared on balsam fir or black spruce foliage. Bacterial DNA from the larval midguts was extracted to amplify and sequence the V6-V8 region of the 16S rRNA gene, using the Roche 454 GS-FLX technology. Our results showed a dominance of Proteobacteria, mainly Pseudomonas spp., in the spruce budworm midgut, irrespective of treatment group. Taxonomic diversity of the midgut microbiota was greater for larvae reared on synthetic diet than for those collected and reared on host plants, a difference that is likely accounted for by several factors. A greater proportion of bacteria from the phylum Bacteroidetes in insects fed artificial diet constituted the main difference between this group and those reared on foliage; within the phylum Proteobacteria, the presence of the genus Bradyrhizobium was also unique to insects reared on artificial diet. Strikingly, a Bray-Curtis analysis showed important differences in microbial diversity among the treatment groups, pointing to the importance of diet and environment in defining the spruce budworm midgut microbiota.

Elucidating unconscious processing with instrumental hypnosis.

Most researchers leverage bottom-up suppression to unlock the underlying mechanisms of unconscious processing. However, a top-down approach - for example via hypnotic suggestion - paves the road to experimental innovation and complementary data that afford new scientific insights concerning attention and the unconscious. Drawing from a reliable taxonomy that differentiates subliminal and preconscious processing, we outline how an experimental trajectory that champions top-down suppression techniques, such as those practiced in hypnosis, is uniquely poised to further contextualize and refine our scientific understanding of unconscious processing. Examining subliminal and preconscious methods, we demonstrate how instrumental hypnosis provides a reliable adjunct that supplements contemporary approaches. Specifically, we provide an integrative synthesis of the advantages and shortcomings that accompany a top-down approach to probe the unconscious mind. Our account provides a larger framework for complementing the results from core studies involving prevailing subliminal and preconscious techniques.