Synesthesia: a return to the body

Synesthesia is a neurological phenomenon whose nature and etiology remain unknown. In this paper, I apply the neurophenomenological perspective to reflect on the very nature of inducers and concurrents, including their perceptual and conceptual dimensions and their stability over time. Additionally, I analyze the role of attention and its influence over synesthesia, which contributes to the difficulties that we, synesthetes, find when sharing our personal experiences with non-synesthetes. Finally, I expose some examples of the current neuroscientific data and propose some insights into the embodied character of synesthesia, stressing the key role of its emotional component. I conclude describing the clinical applications of the findings in the field of synesthesia and their implications for the understanding of cognition in general

Grapheme-color synesthetes show peculiarities in their emotional brain: cortical and subcortical evidence from VBM analysis of 3D-T1 and DTI data

Grapheme-color synesthesia is a neurological phenomenon in which viewing achromatic letters/numbers leads to automatic and involuntary color experiences. In this study, voxel-based morphometry analyses were performed on T1 images and fractional anisotropy measures to examine the whole brain in associator grapheme-color synesthetes. These analyses provide new evidence of variations in emotional areas (both at the cortical and subcortical levels), findings that help understand the emotional component as a relevant aspect of the synesthetic experience. Additionally, this study replicates previous findings in the left intraparietal sulcus and, for the first time, reports the existence of anatomical differences in subcortical gray nuclei of developmental grapheme-color synesthetes, providing a link between acquired and developmental synesthesia. This empirical evidence, which goes beyond modality-specific areas, could lead to a better understanding of grapheme-color synesthesia as well as of other modalities of the phenomenon

Psilocybin, LSD, Mescaline and drug-induced synesthesia

Studies have shown that both serotonin and glutamate receptor systems play a crucial role in the mechanisms underlying drug-induced synesthesia. The specific nature of these mechanisms, however, continues to remain elusive. Here we propose two distinct hypotheses for how synesthesia triggered by hallucinogens in the serotonin-agonist family may occur. One hypothesis is that the drug-induced destabilization of thalamic projections via GABAergic neuronal circuits from sensory areas leads to a disruption of low-level, spontaneous integration of multisensory stimuli. This sort of integration regularly occurs when spatial and temporal attributes match. Destabilization of feedback loops, however, can result in incongruent experiences or binding of random thalamus activation with sensory input in a particular sensory modality. The second hypothesis builds on embodied cognition, cases in which visual images of external stimuli activate task-related neural regions. On this proposal, binding processes that do not normally generate awareness become accessible to consciousness as a result of decreased attentional discrimination among incoming stimuli

Exceptional Abilities in the Spatial Representation of Numbers and Time: Insights from Synesthesia

In the study of basic and high-level cognitive functions, neuroscientists, psychologists, and philosophers have tended to focus on normal psychological processes and on deficits in these processes, whereas the study of exceptional abilities has been largely neglected. Here the authors emphasize the value of researching exceptional abilities. They make the case that studies of exceptional representations, such as of time, number, and space in synesthesia, can provide us with insights regarding the nature of the neurocognitive mechanisms of these dimensions, as well as their developmental, evolutionary, and cultural origins

Synestetické asociace a psychopatologické symptomy.

1 Synestetické asociace a psychopatologické symptomy Marcel Necká Abstrakt Synestézie v obecném smyslu p edstavuje jev intersenzorického a intrasenzorického propojení, které m že být pozorováno za r zných fyziologických a patologických okolností, nap íklad jako kreativita v um ní nebo v ípad n kterých mozkových dysfunkcí. Synestézie jako jev je p edevším formována prost ednictvím transmodálních asociativních spojení, které mohou tvo it kontinuum od tzv. "silných" synestetických jev až k jejím mírným formám, které pravd podobn umož ují tvorbu synestetických metaphor a imaginace. Tato studie je zam ena na projektivní analýzu slovn barevných asociací a jejich vztahu k psychoaptologickým m ením reflektujícím stres, depresi, disociaci a dalších psychometrických m ení u 154 ú astník vybraných z obecné populace. Výsledky této studie jsou v souladu s dosavadními publikovanými poznatky, které dokládají, že sv tlejší barvy jsou mnohem ast ji asociovány s pozitivními emocionálními významy ve srovnání s tmavšími barvami. Navíc výsledky této studie ukazují vztahy t chto barevn -slovních asociací k psychopatologickým symptom m a to prost ednictvím vztahu n kterých specifických slov k symptom m deprese, úzkosti, alexithymie a n kterým symptom m traumatického stresu. Tyto výsledky jsou v souladu s existujícími poznatky...1 Synesthetic associations and psychopathological symptoms Marcel Necká Abstract Synesthesia in general is a phenomenon of intersensory and intrasensory linkage that may be observed in various conditions including artistic creativity and also manifests in conditions of various brain dysfunctions and injuries. Synesthesia is a phenomenon represented by transmodal associative connections that may represent a continuum from strong synesthetic phenomena to its mild forms that may enable creation of "synesthetic" metaphors. This study is focused on projective assessments of word-color association and their relationship to psychopathological measures reflecting stress, depression, dissociation and other psychometric measures in 154 participants selected from general population. The results are in agreement with previous reported studies suggesting that lighter colors are more frequently associated with positive emotional meanings. In addition the results indicate significant relationships of color- word associations to some specific words with depression, anxiety, alexithymia and symptoms of traumatic stress. These results are in ac-cordance with existing findings in context of the so-called metaphorical synesthesia where significant role might be attributed to color intensity. In this context, results of this...Psychiatrická klinika 1. LF a VFN v PrazeDepartment of Psychiatry First Faculty of Medicine and General University Hospital in PragueFirst Faculty of Medicine1. lékařská fakult

Synesthesia as an Intervention to Modify Children’s Access to Enhanced Learning and Memory

Synesthesia is a phenomenal experience where a person reports more than one sensory experience activated for one stimulus. A specific type of interest is grapheme-color synesthesia where a person sees graphemes (letters and numbers) and it elicits a secondary response (color). It is through these experiences that people with grapheme-color synesthesia are given a secondary benefit: enhanced learning and memory. If people in society seek to equip children with the tools they need to succeed and excel in development, and synesthesia is a tool that helps with that, it would be logical to consider synesthesia as an intervention to increase children’s access to enhanced learning and memory. However, in order to assess whether it should be considered for inducement, synesthesia must be evaluated in isolation of its instrumental benefits. This thesis outlines the intrinsic values of synesthesia, the instrumental values, and the applications to children before weighing whether inducement is permissible. Synesthesia is argued to be intrinsically neutral by balancing the positive and negative attributes including their respective counterarguments. Afterwards, instrumental advantages and disadvantages are weighed, and counterarguments are provided to keep a balanced review. Finally, the costs and benefits of synesthesia in the realm of learning and memory are scaled to determine whether induced synesthesia is permissible. This thesis concludes, that in order to permit induced synesthesia, the data must be valid and replicable in order to accurately predict and achieve the correct type of synesthesia and reduce creating more harm than good; therefore, induced synesthesia is not permissible

Olfactory consciousness across disciplines

Our sense of smell pervasively influences our most common behaviors and daily experience, yet little is known about olfactory consciousness. Over the past decade and a half research in both the fields of Consciousness Studies and Olfaction has blossomed, however, olfactory consciousness has received little to no attention. The olfactory systems unique anatomy, functional organization, sensory processes, and perceptual experiences offers a fecund area for exploring all aspects of consciousness, as well as a external perspective for re-examining the assumptions of contemporary theories of consciousness. It has even been suggested that the olfactory system may represent the minimal neuroanatomy that is required for conscious processing. Given the variegated nature of research on consciousness, we include original papers concerning the nature of olfactory consciousness. The scope of the special edition widely incorporates olfaction as it relates to Consciousness, Awareness, Attention, Phenomenal- or Access-Consciousness, and Qualia. Research concerning olfaction and cross-modal integration as it relates to conscious experience is also address. As the initial foray into this uncharted area of research, we include contributions from across all disciplines contributing to cognitive neuroscience, including neurobiology, neurology, psychology, philosophy, linguistics, and computer sciences. It is our hope that this Research Topic will serve as the impetus for future interdisciplinary research on olfaction and consciousness