[fMRI and DTI in delayed development of number processing]. / fMRT und DTI bei Entwicklungsverzögerung der Zahlenverarbeitung.

The neuronal correlate of the current cultural performance arose from developmental processes that can be observed by functional and anatomical magnetic resonance imaging. The velocity of these maturation processes occurs differently between adolescents, causing implications for both school career and academic performance. Regarding spatial-numerical cognition the myelinization of the superior longitudinal bundle appears to be crucial because this fiber connection intermediates between the linguistic nature of number words and conception of their spatial-numerical magnitude. The neuroscientific observation of anatomical brain maturation and its influence on school-relevant number processing may be helpful for educational purposes as well as for school psychology.

[Functional MRI of speech]. / Funktionelle MRT der Sprache.

Speech is a multifactorial term. In relationship with our central organ, speech is a communication medium which in a complex manner includes the production and perception of verbal information. Even within this limitation, imaging exploration of the neuronal basis of verbal communication offers an extensive investigative field which can only be presented in this article as highlights. The main focus is on the technical hurdles of investigations into speech production using functional magnetic resonance imaging (fMRI) and solution options will be presented. The difficulties contained in this aspect are that spoken words can only be poorly assessed in the noise level of the measurements and that the movements of the mouth necessary for speech motoric can lead to technical imaging artefacts. Investigation techniques and designs will be discussed which allow a representation of speech-relevant brain centers despite these problems.

[Functional MRI of the hearing center]. / Funktionelle MRT des Hörzentrums.

Examination of the sense of hearing is a technically difficult undertaking especially with functional magnetic resonance imaging because the machine causes a high noise level during the measurement. This article describes the technical conditions which, nevertheless, allow the auditory capabilities to be tested. Furthermore, every switch point of the auditory pathway and the cortical areas involved, which are technically accessible in an investigation of the sense of hearing are pictorially described.

[Neuroimaging of color and spatial perception]. / "Neuroimaging" der Farb- und Raumwahrnehmung.

Spatial orientation and perception of distance are anchored in the visual system in the same way as color perception. However, different centers with different levels of expression are involved in the various aspects of visual processing starting from the primary visual cortex in the occipital lobes. In this article the investigation methods and designs are described by which the various functions within the visual system can be assigned to the appropriate specialized center in the parietal and temporal lobes using functional magnetic resonance imaging (fMRI).

Hyperechogenicity of the substantia nigra in healthy controls is related to MRI changes and to neuronal loss as determined by F-Dopa PET.

Transcranial ultrasound (TCS) has been shown to reveal hyperechogenicity of the substantia nigra (SN) in Parkinsonian patients and in about 10% of healthy controls. It is hypothesized that SN hyperechogenicity in healthy subjects is a vulnerability marker for idiopathic Parkinson's disease (IPD). Although there is strong evidence that the echomarker results from increased local iron content, the exact pathophysiological mechanisms remain incompletely understood. Thus, prognostic impact can only be estimated. We examined 14 subjects with SN hyperechogenicity (SN+) (7 IPD patients and 7 controls) and 7 healthy controls without the echomarker (SN-) by a magnetic resonance imaging method (MRI; T2 relaxation times) known to reveal tissue inhomogeneity following abnormal iron content and by F-Dopa PET to assess nigrostriatal function.