Neurocognitive Mechanisms of Synesthesia

  title={Neurocognitive Mechanisms of Synesthesia},
  author={Edward M. Hubbard and Virginia S. Ramachandran},
Synesthesia is a condition in which stimulation of one sensory modality causes unusual experiences in a second, unstimulated modality. Although long treated as a curiosity, recent research with a combination of phenomenological, behavioral, and neuroimaging methods has begun to identify the cognitive and neural basis of synesthesia. Here, we review this literature with an emphasis on grapheme-color synesthesia, in which viewing letters and numbers induces the perception of colors. We discuss… 

Figures, Tables, and Topics from this paper

Approaches in Synesthesia Research: Neurocognitive Aspects and Diagnostic Criteria
Synesthesia is a fairly rare phenomenon in which the subject in contact with certain stimulus in one modality experiences unusual extra sensations in other modalities, such as seeing or feeling
Neurophysiology of synesthesia
  • E. Hubbard
  • Psychology, Medicine
    Current psychiatry reports
  • 2007
Recent research examining the neural basis of the two most intensively studied forms of synesthesia suggest that these forms ofsynesthesia are elicited through anomalous activation of color-selective areas, perhaps in concert with hyper-binding mediated by the parietal cortex.
Neuroscience of synesthesia and cross-modal associations
This review summarizes and reflects current knowledge concerning synesthesia in its various aspects, including its cognitive, neural, and behavioral aspects.
Oneiric Synesthesia: Preliminary Evidence for the Occurrence of Synesthetic-Like Experiences During Sleep-Inertia
Synesthesia is a condition that involves atypical binding between two seemingly independent sensory modalities. The neural origin of this condition is controversial: Although some claim that
Neuroanatomical bases for synesthesia and their implications for perception and consciousness
Synesthesia is a condition that affects an individual’s conscious perception of the world. Individuals with this disorder vary greatly, but have in common the phenomenon of cross-modal perceptions.
Sensory Perception: Lessons from Synesthesia
  • J. Harvey
  • Medicine, Psychology
    The Yale journal of biology and medicine
  • 2013
By first appreciating the similarities between normal sensory perception and synesthesia, one can use what is known about synaesthesia, from behavioral and imaging studies, to inform the understanding of "normal" sensory perception.
Synesthesia, Then and Now
Puzzling in its diversity and resistant to simple theoretical accounts, synesthesia has been a subject of scrutiny and investigation for more than a century. Over 30 years ago, the present author
Synesthesia and its Cognitive Correlates
Synesthesia is a neurological condition involving the pairing of senses. For synesthetes, a stimulus invokes a sensory perception; for instance, the letter “B” may be pink or the name “Susan” may
Synesthesia and music perception
It is proposed that the existence of a lower, unconscious degree of synesthesia in non-synesthetes would be functional, aiding the construction of abstract associations between different perceptual fields.
What can synaesthesia tell us about our minds
Synaesthesia is considered here as a cognitive phenomenon in the context of developmental, neuropathological and linguistic perspectives. Developmental synaesthesia seems to arise as an effect of


Synesthesia: A Union of the Senses
For decades, scientists who heard about synesthesia hearing colors, tasting words, seeing colored pain just shrugged their shoulders or rolled their eyes. Now, as irrefutable evidence mounts that
On the Perceptual Reality of Synesthetic Color
2 Synesthesia – the mental mixture of real and illusory sensory experiences – is incredibly fascinating to read or hear about but frustratingly complex to study. Those of us who are not synesthetes
Mechanisms of synesthesia: cognitive and physiological constraints
A neurobiological theory of synesthesia is advanced that fits within a neuroanatomical framework comprising hierarchically organized cortical sensory pathways.
Synesthesia : perspectives from cognitive neuroscience
PART 1: GENERAL OVERVIEW 1. Synesthesia in perspective 2. Some demographic and socio-cultural aspects of synesthesia 3. Varieties of synesthetic experience PART 2: PERCEPTION AND ATTENTION 4. On the
Neonatal Synesthesia: Implications for the Processing of Speech And Faces
A re-analysis of the published literature and new data of my own support the hypothesis that babies confuse the input from different senses. That synesthetic mixing leads to (1) apparent cross-modal
The perceptual reality of synesthetic colors
The subject, in contrast to non-synesthetic subjects, accomplished the task with relative ease because the target of the search had a different synesthetic color from the distractors, indicating that synesthetic experiences appear to originate from a binding of color and form that takes place within central stages of visual processing.
Towards a Synergistic Understanding of Synaesthesia Combining Current Experimental Findings With Synaesthetes' Subjective Descriptions
In synaesthesia, ordinary stimuli elicit extraordinary conscious experiences. For example, standard black digits may elicit highly specific colour experiences and specific tastes may elicit unusual
The phenomenology of synaesthesia
This article supplements our earlier paper on synaesthesia published in JCS (Ramachandran & Hubbard, 2001a). We discuss the phenomenology of synaesthesia in greater detail, raise several new
Anomalous perception in synaesthesia: A cognitive neuroscience perspective
The latest findings on synaesthesia are reviewed, and its possible genetic, neural and cognitive bases are considered, and a neurocognitive framework for understanding anomalous perceptual experiences is proposed.
Functional magnetic resonance imaging of synesthesia: activation of V4/V8 by spoken words
Using functional magnetic resonance imaging (fMRI), this work locates the region activated by speech in synesthetes to area V4/V8 in the left hemisphere, and demonstrates overlap with V3/V4 activation in normal controls in response to color.