Markus Zedler

Hannover Medical School | MHH · Clinic for Psychiatry Social Psychiatry and Psychotherapy

In auditory-visual synaesthesia, all kinds of sound can induce additional visual experiences. To identify the brain regions mainly involved in this form of synaesthesia, functional magnetic resonance imaging (fMRI) has been used during non-linguistic sound perception (chords and pure tones) in synaesthetes and non-synaesthetes. Synaesthetes showed...

Subtitles: Mental Protection by Synesthesia; When Synesthetes Meet with Psychiatrists; Synesthesia as an Advantage; Loneliness; Synesthetes in Conflicts; Social Interactions; Synesthesia Under Stressful Conditions; Narcissism; Sexuality; Empathy and Lucidity.

Introduction: Synaesthesia is a phenomenon in which a certain stimulus induces a concurrent sensory perception; it has an estimated prevalence of 4%. Sexual arousal as an inducer for synaesthetic perceptions is rarely mentioned in the literature but can be found sometimes in case reports about subjective orgasmic experiences. Aims: To examine wheth...

Judgments about personalities and social traits can be made by relatively brief exposure to animate living things. Here we show that unusual architecture in the microstructure of the human brain is related to atypical mental projections of personality and social structure onto things that are neither living nor animate. Our participants experience...

Grapheme-color synesthesia is a normal and healthy variation of human perception. It is characterized by the association of letters or numbers with color perceptions. The etiology of synesthesia is not yet fully understood. Theories include hyperconnectivity in the brain, cross-activation of adjacent or functionally proximate sensory areas of the b...

Synesthesia is a phenomenon in which the stimulation of 1 sensory modality automatically and consistently over time evokes a sensation in the same or a different modality in an idiosyncratic manner. In addition to pure sensory coupling, synesthetes are characterized by cognitive peculiarities, such as abnormalities in perception, creativity, advant...

Blauer Wein oder Buchstaben, zu denen bestimmte Farben gehören, farbige Himmelsrichtungen oder Musik, die hörend auch in Formen und Strukturen erlebt wird. Wer solche Wahrnehmungen hat, gehört zu den Synästhetikern. Lange wurde dieses Phänomen von der Wissenschaft wenig beachtet. Das ist heute anders, auch dank Psychiatern wie Hinderk Emrich. Diese...

Synaesthesia is a phenomenon in which the stimulation of one sensory modality automatically and consistently over time evokes a sensation in the same or a different modality in an idiosyncratic manner. In addition to pure sensory coupling, synaesthetes are characterized by cognitive peculiarities, such as abnormalities in perception, creativity, ad...

Introducing the investigation of neurotrophic growth factor serum levels in synesthetes.

Open questionnaire trial on individual advantages of synaesthesia (Spanish)

Synästhesie ist eine gesunde Normvariante menschlichen Bewusstseins und tritt bei ca. 5 % der Bevölkerung als Kopplung von Sinnesqualitäten auf, die in der Regel mit deutlich mehr kognitiven und seelischen Vorteilen als mit Beeinträchtigungen einhergeht. Auf vielleicht über 150 mögliche verschiedene Arten (6, 7) sind Sinne (auch im weiteren Sinne)...

Neurobiological aspects of synaesthesia are discussed from the perspective of the broader philosophical topic of “syn-aisthesis” and the basic fundamentals of a neuropsychological understanding of perceptual inter-modal integration. Herein, the predominance of conceptualization processes in regard to top-down functions of the brain appears as a pre...

Recent research suggests synesthesia as a result of a hypersensitive multimodal binding mechanism. To address the question whether multimodal integration is altered in synesthetes in general, grapheme-colour and auditory-visual synesthetes were investigated using speech-related stimulation in two behavioural experiments. First, we used the McGurk i...

There is increasing evidence from case reports that synesthesia is more common in individuals with autism spectrum conditions (ASC). Further, genes related to synesthesia have also been found to be linked to ASC and, similar to synaesthetes, individuals with ASC show altered brain connectivity and unusual brain activation during sensory processing....

Neurobiological aspects of synaesthesia are discussed from the perspective of the broader philosophical topic of “syn-aisthesis” and the basic fundamentals of a neuropsychological understanding of perceptual inter-modal integration. Herein, the predominance of conceptualization processes in regard to top-down functions of the brain appears as a pre...

Grapheme-color synesthesia is a condition in which letters are perceived with an additional color dimension. To identify brain regions involved in this type of synesthesia and to analyze functional connectivity of these areas, 18 grapheme-color synesthetes and 18 matched controls were stimulated with letters and pseudo-letters presented in black an...

It has been suggested that synaesthesia is the result of a hyper-sensitive multimodal binding-mechanism. To address the question whether multi-modal integration is altered in synaesthetes in general, grapheme-colour and auditory-visual synaesthetes were studied using the double-flash illusion. This illusion is induced by a single light flash presen...

Despite some principal similarities, there is no systematic comparison between the different types of synesthesia (genuine, acquired and drug-induced). This comprehensive review compares the three principal types of synesthesia and focuses on their phenomenological features and their relation to different etiological models. Implications of this co...

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...

Color percept induction in synaesthetes by hearing words was previously shown to involve activation of visual and specifically color processing cortex areas. While this provides a rationale for the origin of the anomalous color percept the question of mechanism of this crossmodal activation remains unclear. We pursued this question with fMRI in col...

Objective. Foreign body ingestion can be a challenge to multiprofessional approaches involving medical, surgical, neurological, and psychiatric teams.Case presentation. A 41-year-old male patient with intellectual disabilities presented after having swallowed approximately 20 sharp objects. While admitted to a psychiatric ward, surgeons removed a g...

Background and Objectives: With the Cyberspace´s exponential growth of influence questions arise about its mental impacts. The presented study examines the question whether the dependent use of the Internet can be understood as an impulse control disorder, an addiction or as a symptom of other psychiatric conditions. Methods: Internet dependent pa...

Objetivos: El trastorno por déficit de atención con hiperactividad (TDAH) tiene una gran importancia clínica no sólo por su elevada prevalencia sino también por su frecuente comorbilidad con enfermedades que están relacionadas con este trastorno. Diversos estudios han sido capaces de demostrar que el TDAH constituye un importante factor de riesgo p...

Attention-deficit/hyperactivity disorder (ADHD) is of great clinical importance not only because of its high prevalence but also due to the frequent comorbid illnesses that are connected with this disorder. Several studies were able to demonstrate that ADHD constitutes a significant risk factor for the exacerbation of habit-forming illnesses, i.e....

Attention deficit/hyperactivity disorder (ADHD) is a widely examined disease in childhood. There is evidence that the disease responds well to medication with methylphenidate (MPH). The effect of MPH in adults with ADHD is a question that is often raised, because many adults request such therapy today. As yet, there is a lack of studies on event-re...

OBJECTIVE In psychiatric contexts, the quick distribution of virtual techniques in private and professional everyday life gives rise to the question, if these can evoke a psychological addiction. Yet, the diagnostic assessment of internet or computer game dependency remains problematic. METHODS Within a study with 23 internet-dependent patients wit...

In psychiatric contexts, the quick distribution of virtual techniques in private and professional everyday life gives rise to the question, if these can evoke a psychological addiction. Yet, the diagnostic assessment of internet or computer game dependency remains problematic. Within a study with 23 internet-dependent patients with significant psyc...

Farben hören – Geschmack sehen: Synsthetiker erleben eine Vermischung ihrer Sinne. Die Erforschung dieses Phnomens liefert spannende Einblicke in die Art und Weise, wie Sinneseindrücke im menschlichen Gehirn verarbeitet werden. Synsthesie als Lebensform erweist sich als Paradigma eines Selbstverstndnisses des Menschen, jenseits einer Physik der Rev...

Accidental intrarterial injections are not uncommon in medical treatments. This is also true for uncontrolled injections by drug-addicts. Since 2002 a number of 600 heavy opiate addicts in Germany are substituted in a country-wide study with pure diacetylmorphine (Heroine). We report the course and outcome of three cases of accidental intraarterial...

Die akzidentelle intraarterielle Injektion von Medikamenten und Begleitstoffen stellt eine nicht seltene medizinische Komplikation dar. Dies gilt auch fur unkontrollierte Autoinjektionen drogenabhangiger Patienten. Seit dem Jahre 2002 werden im Rahmen der bundesdeutschen Studie zur heroingestutzten Behandlung Opiatabhangiger ca. 600 Schwerstabhangi...

When humans perceive an object, their perceptory organs transform the properties of the object into percepts of different modalities, which are then related with one another in such a way that the object appears as a unified entity in consciousness. This neurobiological process, which is still largely unknown, is called "binding". When during the p...

Acamprosate is effective in reducing alcohol intake in weaned alcoholics. We were interested if acamprosate had an effect on the excitability of cortical motoneurons determined by transcranial magnetic stimulation (TMS). We studied 12 male healthy volunteers (mean age 29.5 years, SD = 4.8) who were either treated with 6 tablets of acamprosate (each...

Several studies have shown acamprosate (calciumacetylhomotaurinate) to increase abstinence rates in weaned alcoholics. Chronic alcoholics often suffer from cognitive deficits. Since acamprosate appears to interact with N-methyl-D-aspartate (NMDA) receptors, a subclass of glutamate receptors playing an important role in learning and memory processes...

The possible effects on psychomotor performance, concentration, attention, and mood of acamprosate (calciumacetylhomotaurinate) were assessed using a randomized, double-blind, cross-over, placebo-controlled design involving 12 healthy male volunteers. Acamprosate 2 g daily per os or placebo was administered for seven days and separated by washout i...