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NeuroImage Oct 2023Visual illusions have long been used to study visual perception and contextual integration. Neuroimaging studies employ illusions to identify the brain regions involved... (Meta-Analysis)
Meta-Analysis Review
Visual illusions have long been used to study visual perception and contextual integration. Neuroimaging studies employ illusions to identify the brain regions involved in visual perception and how they interact. We conducted an Activation Likelihood Estimation (ALE) meta-analysis and meta-analytic connectivity modeling on fMRI studies using static and motion illusions to reveal the neural signatures of illusory processing and to investigate the degree to which different areas are commonly recruited in perceptual inference. The resulting networks encompass ventral and dorsal regions, including the inferior and middle occipital cortices bilaterally in both types of illusions. The static and motion illusion networks selectively included the right posterior parietal cortex and the ventral premotor cortex respectively. Overall, these results describe a network of areas crucially involved in perceptual inference relying on feed-back and feed-forward interactions between areas of the ventral and dorsal visual pathways. The same network is proposed to be involved in hallucinogenic symptoms characteristic of schizophrenia and other disorders, with crucial implications in the use of illusions as biomarkers.
Topics: Humans; Illusions; Likelihood Functions; Neural Networks, Computer; Visual Perception; Head
PubMed: 37591478
DOI: 10.1016/j.neuroimage.2023.120335 -
Schizophrenia Research Mar 2024
Topics: Humans; Neurobiology; Hallucinations; Brain; Patient Outcome Assessment
PubMed: 38238226
DOI: 10.1016/j.schres.2023.12.018 -
Current Cardiology Reports Oct 2023Blood pressure (BP) fluctuations outside of clinic are increasingly recognized for their role in the development of cardiovascular disease, syncope, and premature death... (Review)
Review
PURPOSE OF REVIEW
Blood pressure (BP) fluctuations outside of clinic are increasingly recognized for their role in the development of cardiovascular disease, syncope, and premature death and as a promising target for tailored hypertension treatment. However, current cuff-based BP devices, including home and ambulatory devices, are unable to capture the breadth of BP variability across human activities, experiences, and contexts.
RECENT FINDINGS
Cuffless, wearable BP devices offer the promise of beat-to-beat, continuous, noninvasive measurement of BP during both awake and sleep periods with minimal patient inconvenience. Importantly, cuffless BP devices can characterize BP variability, allowing for the identification of patient-specific triggers of BP surges in the home environment. Unfortunately, the pace of evidence, regulation, and validation testing has lagged behind the pace of innovation and direct consumer marketing. We provide an overview of the available technologies and devices for cuffless BP monitoring, considerations for the calibration and validation of these devices, and the promise and pitfalls of the cuffless BP paradigm.
Topics: Humans; Blood Pressure; Illusions; Blood Pressure Determination; Hypertension; Sphygmomanometers
PubMed: 37688763
DOI: 10.1007/s11886-023-01932-4 -
Proceedings of the National Academy of... Jul 2023Auditory perception is traditionally conceived as the perception of sounds-a friend's voice, a clap of thunder, a minor chord. However, daily life also seems to present...
Auditory perception is traditionally conceived as the perception of sounds-a friend's voice, a clap of thunder, a minor chord. However, daily life also seems to present us with experiences characterized by the absence of sound-a moment of silence, a gap between thunderclaps, the hush after a musical performance. In these cases, do we positively silence? Or do we just , and merely judge or infer that it is silent? This longstanding question remains controversial in both the philosophy and science of perception, with prominent theories holding that sounds are the only objects of auditory experience and thus that our encounter with silence is cognitive, not perceptual. However, this debate has largely remained theoretical, without a key empirical test. Here, we introduce an empirical approach to this theoretical dispute, presenting experimental evidence that silence can be genuinely perceived (not just cognitively inferred). We ask whether silences can "substitute" for sounds in event-based auditory illusions-empirical signatures of auditory event representation in which auditory events distort perceived duration. Seven experiments introduce three "silence illusions"-the one-silence-is-more illusion, silence-based warping, and the oddball-silence illusion-each adapted from a prominent perceptual illusion previously thought to arise only from sounds. Subjects were immersed in ambient noise interrupted by silences structurally identical to the sounds in the original illusions. In all cases, silences elicited temporal distortions perfectly analogous to the illusions produced by sounds. Our results suggest that silence is truly heard, not merely inferred, introducing a general approach for studying the perception of absence.
Topics: Humans; Illusions; Noise; Sound; Auditory Perception; Hearing; Acoustic Stimulation
PubMed: 37428927
DOI: 10.1073/pnas.2301463120 -
The International Journal of... Dec 2023I explore some similarities between experiences of music and of analytic sessions. I focus on qualities of evanescence, the way that music - in contrast to many other...
I explore some similarities between experiences of music and of analytic sessions. I focus on qualities of evanescence, the way that music - in contrast to many other arts - in one perspective only lasts as long as it is actually being played. Then it's over. The analyst-patient discussion in a session is similar. Yet the psychic reverberations of some transient, fugitive moments may last a lifetime. And even when no verbally profound understanding is occurring, nevertheless the patient-analyst encounter is emotionally significant. I illustrate this with a clinical example. I explore transference as illusion, and the relationship between truth and illusion in terms of Bion's O. I end with thoughts about the paradoxical value of the illusoriness of aesthetics and nature as considered by Freud in his short paper "On Transience" (1916), and the grin of Lewis Carol's Cheshire Cat, left hanging in the air.
Topics: Humans; Psychoanalytic Therapy; Illusions; Catalase; Esthetics; Music
PubMed: 38127484
DOI: 10.1080/00207578.2023.2258956 -
Brain Topography Sep 2023The purpose of this scoping review is to provide updated information on the neural basis and neurophysiological features associated with unilateral spatial neglect (USN)... (Review)
Review
The purpose of this scoping review is to provide updated information on the neural basis and neurophysiological features associated with unilateral spatial neglect (USN) recovery. We applied the Preferred Reporting Systems for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) framework and identified 16 relevant papers from the databases. Critical appraisal was performed by two independent reviewers using a standardized appraisal instrument developed by the PRISMA-ScR. We identified and categorized investigation methods for the neural basis and neurophysiological features of USN recovery after stroke using magnetic resonance imaging (MRI), functional MRI, and electroencephalography (EEG). This review found two brain-level mechanisms underlying USN recovery at the behavioral level. These include the absence of stroke-related damage to the right ventral attention network during the acute phase and compensatory recruitment of analogous areas of the undamaged opposite hemisphere and prefrontal cortex during visual search tasks in the subacute or later phases. However, the relationship between the neural and neurophysiological findings and improvements in USN-related activities of daily living remains unknown. This review adds to the growing body of evidence regarding the neural mechanisms underlying USN recovery.
Topics: Humans; Activities of Daily Living; Brain; Functional Laterality; Perceptual Disorders; Stroke; Stroke Rehabilitation
PubMed: 37410274
DOI: 10.1007/s10548-023-00980-x -
Current Opinion in Anaesthesiology Oct 2023Chronic postamputation pain (cPAP) remains a clinical challenge, and current understanding places a high emphasis on prevention strategies. Unfortunately, there is still... (Review)
Review
PURPOSE OF REVIEW
Chronic postamputation pain (cPAP) remains a clinical challenge, and current understanding places a high emphasis on prevention strategies. Unfortunately, there is still no evidence-based regimen to reliably prevent chronic pain after amputation.
RECENT FINDINGS
Risk factors for the development of phantom limb pain have been proposed. Analgesic preventive interventions are numerous and no silver bullet has been found. Novel techniques such as neuromodulation and cryoablation have been proposed. Surgical techniques focusing on reimplantation of the injured nerve might reduce the incidence of phantom limb pain after surgery.
SUMMARY
Phantom limb pain is a multifactorial process involving profound functional and structural changes in the peripheral and central nervous system. These changes interact with individual medical, psychosocial and genetic patient risk factors. The patient collective of amputees is very heterogeneous. Available evidence suggests that efforts should focus on prevention of phantom limb pain, since treatment is notoriously difficult. Questions as yet unanswered include the evidence-base of specific analgesic interventions, their optimal "window of opportunity" where they may be most effective, and whether patient stratification according to biopsychosocial risk factors can help guide preventive therapy.
Topics: Humans; Phantom Limb; Chronic Pain; Amputation, Surgical; Amputees; Analgesics
PubMed: 37552016
DOI: 10.1097/ACO.0000000000001298 -
Scientific Reports Jul 2023Chronic pain alters the experience of owning a body and leads to disturbances in bodily perception. We tested whether women with fibromyalgia (FM) are receptive to...
Chronic pain alters the experience of owning a body and leads to disturbances in bodily perception. We tested whether women with fibromyalgia (FM) are receptive to bodily illusions of owning a visible and progressively invisible body in immersive virtual reality (VR), and what modulates this experience. Twenty patients participated in two experimental sessions; each session included two conditions in a counterbalanced order. We found that patients with FM could indeed experience virtual embodiment. Sentiment analysis revealed significantly more positive reactions to the progressively invisible body, yet twice as many patients declared they preferred the illusion of a visible virtual body. A linear mixed model revealed that the strength of embodiment was positively associated with body perception disturbances and negatively associated with FM symptoms intensity. No effect of pain during the VR experience nor interoception awareness on embodiment was found. The results indicated that patients with FM are receptive to virtual bodily illusions and that the impact of the embodiment depends on affective reactions, the level of cognitive body distortions, and the intensity of symptoms. Importantly, there is a large variation among patients which should be considered in future VR-based interventions.
Topics: Humans; Female; Fibromyalgia; Illusions; Virtual Reality; Chronic Pain; Interoception
PubMed: 37400503
DOI: 10.1038/s41598-023-36861-3 -
Parkinsonism & Related Disorders Aug 2023Pareidolia, a form of visual illusions phenomenologically similar to complex visual hallucinations, is a phenomenon that is associated with visual hallucinations in...
INTRODUCTION
Pareidolia, a form of visual illusions phenomenologically similar to complex visual hallucinations, is a phenomenon that is associated with visual hallucinations in dementia with Lewy bodies (DLB). This study aimed to identify commonalities and differences in behavioral and neural correlates between pareidolic illusions and visual hallucinations in DLB.
METHODS
Forty-three patients with DLB underwent the scene pareidolia test, which evokes and measures pareidolic illusions, and standardized neuropsychological and behavioral assessments. Regional cerebral blood flow (rCBF) was measured by single-photon emission computed tomography. Factor analysis was performed to assess the relationships among pareidolic illusions, cognitive functions, and behavioral symptoms. Partial least squares correlation analysis was used to investigate the relationship between these symptoms and rCBF.
RESULTS
Factor analysis yielded three behavior factors: the first factor (hallucinations/fluctuations) consisted of pareidolic illusions, visual hallucinations, and fluctuating cognition; the second factor (general cognitive function) consisted of general cognitive function and working memory; and the third factor (visual processing) consisted of visual processing and pareidolic illusions. Partial least squares correlation analysis identified two brain-behavior correlation patterns: (1) rCBF reduction in the frontal and perisylvian/periventricular regions was associated with lower general cognitive function and lower visual processing; and (2) rCBF reduction in the bilateral occipitotemporal cortex was associated with more severe hallucinations/fluctuations and lower visual processing.
CONCLUSIONS
At the behavioral level, pareidolic illusions are associated with visual hallucinations, fluctuating cognition, and visual processing in DLB. At the neural level, pareidolic illusions may arise from the synergistic effects of global neuropathological changes and occipitotemporal cortical dysfunctions.
Topics: Humans; Illusions; Lewy Body Disease; Hallucinations; Cognition; Brain
PubMed: 37441885
DOI: 10.1016/j.parkreldis.2023.105513 -
Psychonomic Bulletin & Review Apr 2024Across the millennia, and across a range of disciplines, there has been a widespread desire to connect, or translate between, the senses in a manner that is meaningful,... (Review)
Review
Across the millennia, and across a range of disciplines, there has been a widespread desire to connect, or translate between, the senses in a manner that is meaningful, rather than arbitrary. Early examples were often inspired by the vivid, yet mostly idiosyncratic, crossmodal matches expressed by synaesthetes, often exploited for aesthetic purposes by writers, artists, and composers. A separate approach comes from those academic commentators who have attempted to translate between structurally similar dimensions of perceptual experience (such as pitch and colour). However, neither approach has succeeded in delivering consensually agreed crossmodal matches. As such, an alternative approach to sensory translation is needed. In this narrative historical review, focusing on the translation between audition and vision, we attempt to shed light on the topic by addressing the following three questions: (1) How is the topic of sensory translation related to synaesthesia, multisensory integration, and crossmodal associations? (2) Are there common processing mechanisms across the senses that can help to guarantee the success of sensory translation, or, rather, is mapping among the senses mediated by allegedly universal (e.g., amodal) stimulus dimensions? (3) Is the term 'translation' in the context of cross-sensory mappings used metaphorically or literally? Given the general mechanisms and concepts discussed throughout the review, the answers we come to regarding the nature of audio-visual translation are likely to apply to the translation between other perhaps less-frequently studied modality pairings as well.
Topics: Humans; Visual Perception; Auditory Perception; Synesthesia; History, 20th Century
PubMed: 37803233
DOI: 10.3758/s13423-023-02343-w