Synesthetic Perception Research Articles

Синестезия при аутизме

Synaesthesia — a phenomenon of perception, when stimulation of one sensory modality triggers a perception in one or more other sensory modalities. Synaesthesia is not uniform and can manifest itself in different ways. As the sensations and their interpretation vary in different periods of time, it makes it hard to study this phenom¬enon. The article presents the classification of different forms of synaesthesia, including sensory and cognitive; and bimodal and multimodal synaesthesia. Some synaesthetes have several forms and variants of synaesthesia, while others – just one form of it. Although synaesthesia is not specific to autism spectrum disorders, it is quite common among autistic individuals. The article deals with the most common forms of synaesthesia in autism, advantages and problems of synesthetic perception in children with autism spectrum disorders, and provides some advice to parents how to recognise synaesthesia in children with autism.

Cross-modal, bidirectional priming in grapheme-color synesthesia.

Grapheme-color synesthetes perceive achromatic graphemes to be inherently colored. In this study grapheme-color synesthetes and non-synesthetes discriminated (1) the color of visual targets presented along with aurally presented digit primes, and (2) the identity of aurally presented digit targets presented with visual color primes. Reaction times to visual color targets were longer when the color of the target was incongruent with the synesthetic percept reported for the prime. Likewise, discriminating aurally presented digit targets took longer when the color of the prime was incongruent with the synesthetic percept for the target. These priming effects were absent in non-synesthetes. We conclude that binding between digits and colors in grapheme-color synesthetes can occur bidirectionally across senses. The results are in line with the idea that synesthesia is the result of linking inducing stimuli (e.g. digits) to synesthetic percepts (colors) at an abstract - supra-modal - conceptual level of processing.

Chapter 22 - Auditory synesthesias

Synesthesia is experienced when sensory stimulation of one sensory modality (the inducer) elicits an involuntary or automatic sensation in another sensory modality or different aspect of the same sensory modality (the concurrent). Auditory synesthesias (AS) occur when auditory stimuli trigger a variety of concurrents, or when non-auditory sensory stimulations trigger auditory synesthetic perception. The AS are divided into three types: developmental, acquired, and induced. Developmental AS are not a neurologic disorder but a different way of experiencing one's environment. They are involuntary and highly consistent experiences throughout one's life. Acquired AS have been reported in association with neurologic diseases that cause deafferentation of anterior optic pathways, with pathologic lesions affecting the central nervous system (CNS) outside of the optic pathways, as well as non-lesional cases associated with migraine, and epilepsy. It also has been reported with mood disorders as well as a single idiopathic case. Induced AS has been reported in experimental and postsurgical blindfolding, as well as intake of hallucinogenics or psychedelics. In this chapter the three different types of synesthesia, their characteristics, and phenomologic differences, as well as their possible neural mechanisms are discussed.

The brain of synesthetes

Synesthesia is a fascinating phenomenon in which a particular perception induces a concurrent perception resulting in a kind of double perception. This phenomenon has received considerable attraction in the last 15 years by neuroscientists and cognitive psychologists. Here I will summarize and discuss some of the main findings and ideas from this research. First, I will discuss the main neurophysiological models trying to explain this extraordinary phenomenon. Secondly, I will describe the findings trying to delineate the time course of synesthetic perception in relation to the associated neurophysiological models. Finally, current findings reporting specific and general neuroanatomical features of the synesthete’s brain will be discussed. These findings will be integrated into the current models about the neurophysiological underpinnings of synesthesia.

Development of an Evaluation Method for Degrees of Synesthetic Perception

Development of an Evaluation Method for Degrees of Synesthetic Perception

Synesthetic grapheme-color percepts exist for newly encountered Hebrew, Devanagari, Armenian and Cyrillic graphemes.

Grapheme-color synesthetes experience color, not physically present, when viewing symbols. Synesthetes cannot remember learning these associations. Must synesthetic percepts be formed during a sensitive period? Can they form later and be consistent? What determines their nature? We tested grapheme-color synesthete, MC2, before, during and after she studied Hindi abroad. We investigated whether novel graphemes elicited synesthetic percepts, changed with familiarity, and/or benefited from phonemic information. MC2 reported color percepts to novel Devanagari and Hebrew graphemes. MC2 monitored these percepts over 6months in a Hindi-speaking environment. MC2 and synesthete DN, reported synesthetic percepts for Armenian graphemes, or Cyrillic graphemes+phonemes over time. Synesthetes, not controls, reported color percepts for novel graphemes that gained consistency over time. Phonemic information did not enhance consistency. Thus, synesthetes can form and consolidate percepts to novel graphemes as adults. These percepts may depend on pre-existing grapheme-color relationships but they can flexibly shift with familiarity.

<i>Dietari</i> von Tàpies - Ritualisierung und Revitalisierung des Alltags

Summary: This essay deals with Dietari (2002), a cycle of five pictures dating from Tapies’ last creative period. In this work some central elements of his esthetics flow together within the frame of diary, producing a dimension of existential significance. The pictures show daily ordinary activities such as walking, eating, digesting and washing, which, after being transposed in an esthetic context and enriched by symbols and penetrating signs, expose features of a ritual. First, we identify the diary as a place of mediation between routine, art and ritual. Then we retrace the role of the process of integration and conversion of symbolic and linguistic signs on different levels. By contemplating each of the five paintings and their relations to one another, we can immerse ourselves in an interplay of associations and possible meanings. One can observe two central aspects: objects and signs reacquire their original gesture and their everyday context. As a matter of fact, the figurative signs cannot be removed from artwork, for they incite interactive participation, while mental and sensorial processes of synesthetic perception have to be seen as a unity. Tàpies does not limit himself to the artistic ritualization of the profane, but uses it as a way of influencing everyday acting by restoring its fully procedural meaning. [Keywords: Tàpies; diary; ritual; mediation; gesture; synesthetic perception; procedural ritualization]

Why are there different types of synesthete?

For people with synesthesia, sensations in two modalities are experienced when only one is stimulated (e.g., auditory stimuli might trigger colors and sounds). Synesthetes are manifestly different to the general population, but can also be different to each other. First, the condition is widely heterogeneous in that 60–150 different manifestations of synesthesia have been identified (e.g., auditory stimuli might trigger colors, shapes, flavors and so on; Cytowic and Eagleman, 2009). Second, synesthetes can differ on the quality of their synesthetic perceptions even within a given variant. Some experience their synesthetic percepts as being similar in quality to a real-world perceptions (e.g., synesthetic colors might be projected onto external objects and be difficult to dissociate from real-world colors) while other synesthetes experience less “veridical” percepts (see below). In this opinion piece I ask whether this particular difference—known as the “projector” vs. “associator” distinction—might fall out naturally from another, independent psychological quality.

Patterns of neural activity associated with synesthetic color perception: a case study

Patterns of neural activity associated with synesthetic color perception: a case study

Disinhibited feedback as a cause of synesthesia: Evidence from a functional connectivity study on auditory-visual synesthetes

In synesthesia, certain stimuli to one sensory modality lead to sensory perception in another unstimulated modality. In addition to other models, a two-stage model is discussed to explain this phenomenon, which combines two previously formulated hypotheses regarding synesthesia: direct cross-activation and hyperbinding. The direct cross-activation model postulates that direct connections between sensory-specific areas are responsible for co-activation and synesthetic perception. The hyperbinding hypothesis suggests that the inducing stimulus and the synesthetic sensation are coupled by a sensory nexus area, which may be located in the parietal cortex. This latter hypothesis is compatible with the disinhibited feedback model, which suggests unusual feedback from multimodal convergence areas as the cause of synesthesia. In this study, the relevance of these models was tested in a group (n=14) of auditory-visual synesthetes by performing a functional connectivity analysis on functional magnetic resonance imaging (fMRI) data. Different simple and complex sounds were used as stimuli, and functionally defined seed areas in the bilateral auditory cortex (AC) and the left inferior parietal cortex (IPC) were used for the connectivity calculations. We found no differences in the connectivity of the AC and the visual areas between synesthetes and controls. The main finding of the study was stronger connectivity of the left IPC with the left primary auditory and right primary visual cortex in the group of auditory-visual synesthetes. The results support the model of disinhibited feedback as a cause of synesthetic perception but do not suggest direct cross-activation.

The influence of synesthesia on eye movements: No synesthetic pop-out in an oculomotor target selection task

Recent research on grapheme-colour synesthesia has focused on whether visual attention is necessary to induce a synesthetic percept. The current study investigated the influence of synesthesia on overt visual attention during an oculomotor target selection task. Chromatic and achromatic stimuli were presented with one target among distractors (e.g. a '2' (target) among multiple '5's (distractors)). Participants executed an eye movement to the target. Synesthetes and controls showed a comparable target selection performance across conditions and a 'pop-out effect' was only seen in the chromatic condition. As a pop-out effect was absent for the synesthetes in the achromatic condition, a synesthetic element appears not to elicit a synesthetic colour, even when it is the target. The synesthetic percepts are not pre-attentively available to distinguish the synesthetic target from synesthetic distractors when elements are presented in the periphery. Synesthesia appears to require full recognition to bind form and colour.

Interactive Textile Expressions in Spatial Design: Architecture as Synesthetic Expression

Extending the role of the surface from just an embellishment of the tectonics to communicative devices challenges the traditional design process in architecture. Through a series of design examples, the paper presents a research program that introduces and discusses a new grammar of ornamentation generated by the relation between surface expression and the act of use in the build space. Projects such as Knitted light, Touching loops, Designing with heat and Tactile glow are examples meant to analyze the relation between material, space, time and interaction expression through the design of three dimensional knitted interactive textile structures. The design process joins together different design fields such as architectural, textile and interaction design in order to re-define the relation between human being and space. The design process starts with the microstructure of the textile element and ends with the space design using the interaction design as a tool to relate the human presence to space. The paper aims to propose new interactive spatial expressions created by the integration of computational technology into soft interactive textile surfaces that enable the user to perceive the complexity of the architectural space through a synesthetic perception, that exceeds the limits of visuality.

A Whole-Genome Scan and Fine-Mapping Linkage Study of Auditory-Visual Synesthesia Reveals Evidence of Linkage to Chromosomes 2q24, 5q33, 6p12, and 12p12

Synesthesia, a neurological condition affecting between 0.05%-1% of the population, is characterized by anomalous sensory perception and associated alterations in cognitive function due to interference from synesthetic percepts. A stimulus in one sensory modality triggers an automatic, consistent response in either another modality or a different aspect of the same modality. Familiality studies show evidence of a strong genetic predisposition; whereas initial pedigree analyses supported a single-gene X-linked dominant mode of inheritance with a skewed F:M ratio and a notable absence of male-to-male transmission, subsequent analyses in larger samples indicated that the mode of inheritance was likely to be more complex. Here, we report the results of a whole-genome linkage scan for auditory-visual synesthesia with 410 microsatellite markers at 9.05 cM density in 43 multiplex families (n = 196) with potential candidate regions fine-mapped at 5 cM density. Using NPL and HLOD analysis, we identified four candidate regions. Significant linkage at the genome-wide level was detected to chromosome 2q24 (HLOD = 3.025, empirical genome-wide p = 0.047). Suggestive linkage was found to chromosomes 5q33, 6p12, and 12p12. No support was found for linkage to the X chromosome; furthermore, we have identified two confirmed cases of male-to-male transmission of synesthesia. Our results demonstrate that auditory-visual synesthesia is likely to be an oligogenic disorder subject to multiple modes of inheritance and locus heterogeneity. This study comprises a significant step toward identifying the genetic substrates underlying synesthesia, with important implications for our understanding of the role of genes in human cognition and perception.

Kinaesonics: The intertwining relationship of body and sound

The focus of this article is on the sensation of the body beneath the mediated and the unique nature and particular forms of sensation and perceptions prompted by interactive technology with particular reference to kinaesonic gestures. These topics will be discussed from the point of view of practice with specific reference to the artists' work with the Bodycoder system and their 2005 work The Suicided Voice. The article will discuss how on-the-body technology alters a performer's perception and sensation prompting new forms of cross-modal (synesthetic) perception. The nature of the ‘intertwining’ relationship between the sensual and the sonic, inherent in kinaesonic operations, will be outlined. The article will discuss how the intimacy of on-the-body technology problematizes expression, particularly real-time manipulation. The authors will move on to discuss how the natural movement vocabulary of the body becomes the expressive medium for the generation and manipulation of sound. How flexible protocols and a fluid interface that can be re-configured for each new piece of work allow the artists to put the body at the expressive and contextual centre of the work.

On Perceptual Metaphors

Metaphors reflect processes of thinking and, consequently, appear not just in language but in perception as well. A notable example of metaphorical perception is synesthesia, in which music or voices may be perceived to have shapes, textures, or colors. Another example is physiognomic perception, in which dark objects may be perceived as gloomy or bright ones may be perceived as happy. Synesthetic perception and physiognomic perception alike reveal the presence of deep similarities across different sense modalities, and many of these similarities appear to be inherent to perception. In this regard, intersensory and physiognomic metaphors reflect natural rather than conventional symbols or signs. Despite their perceptual origin, however, metaphorical relations evident in synesthetic and physiognomic perception are also represented in and accessible through language. Consequently, in information processing tasks requiring people to identify or categorize perceptual stimuli, linguistic or abstract proces...

Synesthetic Perception: Alexander Scriabin's Color Hearing

Scriabin's decision to orchestrate his fifth symphony "Prometheus" with a "counterpoint of light" resulted from his perception of sound as literal color. This phenomenon is known as synesthesia, and by the early decades of this century, well over 100 specialized case studies had appeared in the experimental literature. The present article is in two parts. The first is a general discussion of the vast literature on synesthesia. With this perspective, Scriabin's color hearing can be understood to have resulted from a typical synesthetic pairing of diverse sensory stimuli. In part two, the composer's personal perception is examined, and an analysis of the "Tastiera per luce" in the orchestral score is presented. This part for colored light serves a dual function by indicating particular colors to be projected during performance as well as all transposition levels of the six-note pitch collection employed exclusively in the composition.

Synesthetic perception and poetic metaphor.

Synesthetic perception and poetic metaphor.

Synesthetic perception and poetic metaphor.

To explore the role of cross-modal perception in the apprehension of synesthetic metaphors, subjects read 15 short lines from poetry, each of which contained a metaphor relating visual and auditory qualities; the subjects' task was to set the loudness of a 1000-Hz tone and the brightness of a white light to match the levels implied by each metaphor. The sound settings and light settings suggest that a cross-modal equivalence between loudness and brightness largely underlay the responses to the metaphors. This general cross-modal equivalence was characterized by some notable intersubject differences and was modified, in part, by certain metaphors that resisted complete equivalence. Even so, the metaphorically induced settings of loudness and brightness are mainly governed by a cross-modality matching function that is qualitatively like the relation found in people with visual-auditory synesthesia, and that is quantitatively like the function obtained in more traditional psychophysical studies.

Synesthesia: II. Psychophysical relations in the synesthesia of geometrically shaped taste and colored hearing

The psychophysical function in two synesthetic subjects, one with geometrically shaped taste and the other with colored hearing, is investigated. Each synesthete is compared with three control subjects. Pilot studies are used to construct appropriate response domains. Compared to controls, synesthetes give a restricted set of responses that are also asymmetric with respect to the range of choices available in various subsets of the response domain. A combination of absolute and relative effects is also distinctive of synesthetic percepts. It is concluded that synesthesia is a distinct phenomenon unlike ordinary mediated associations, and occupies an intermediate position in the range of simple to complex brain mechanisms.

Bright sneezes and dark coughs, loud sunlight and soft moonlight.

Synesthetic metaphors (such as "the dawn comes up like thunder") are expressions in which words or phrases describing experiences proper to one sense modality transfer their meanings to another modality. In a series of four experiments, subjects used scales of loudness, pitch, and brightness to evaluate the meanings of a variety of synesthetic (auditory-visual) metaphors. Loudness and pitch expressed themselves metaphorically as greater brightness; in turn, brightness expressed itself as greater loudness and as higher pitch. Although loudness thus shared with brightness a metaphorical connection, pitch and brightness showed a connection that was closer and that applied more generally to different kinds of visual brightness. The ways that people evaluate synesthetic metaphors emulate the characteristics of synesthetic perception, thereby suggesting that synesthesia in perception and synesthesia in language both may emenate from the same source-from a phenomenological similarity in the makeup of sensory experiences of different modalities.