Morphometric differences in the Heschl's gyrus of hearing impaired and normal hearing infants.

This study investigates the morphometry of Heschl's gyrus and its included primary auditory cortex (PAC) in hearing impaired (HI) and normal hearing (NH) infants. Fourty-two infants, age 8-19 months, with NH (n = 26) or hearing impairment (n = 16) were studied using high-resolution 3D magnetic resonance imaging. Gray matter (GM) and white matter (WM) volumes were obtained using software for automatic brain imaging segmentation to estimate the volume of each tissue within manually defined regions for the anterior portion of Heschl's gyrus (aHG) in each individual subject, transformed to an infant brain template space. Interactions among group (HI, NH), tissue type (GM, WM), and hemisphere (left, right) were examined using analysis of variance. Whole-brain voxel-based morphometry was utilized to explore volume differences between groups across the entire brain. The HI group showed increased GM and decreased WM in aHG compared with the NH group; likely effects of auditory deprivation. The HI group did not exhibit their typical L > R asymmetry pattern that the NH group showed. Increased GM in aHG in HI infants may represent abnormal cortical development in PAC as seen in animal models of sensory deprivation. Lower WM volume is consistent with studies with deaf adults.

4.1 Web-based interactive learning programmes.

In the future, the training of competent dentists will need to take advantage of up-to-date digital technologies and learning practices. In order to accomplish this, the following goals should be considered: i) the design of 'customizable' web-based curriculum matrices that accommodate the training philosophies and resources of individual dental schools; ii) the development of digital instructional modules that can be incorporated or downloaded into specific parts of a curriculum; iii) the establishment of an e-consortium, which provides peer view and guidance in the design of teaching modules, and which is responsible for the storage, maintenance, and distribution of teaching modules within the consortium; iv) the development of central human and physical resources at each dental school to enable the seamless delivery of instructional modules in a variety of learning environments; and v) the assessment and provision of ICT training to students and faculty with respect to the use of computers and related digital technologies and educational software programmes. These goals should lead to the creation of a 'virtual dental school'. Within this project summative and formative evaluations should be performed during both the production and development of teaching material (e-learning material) and the learning process. During the learning process the following aspects should be measured and evaluated: i) students' behaviour; and ii) effectiveness, retention and the transfer of e-learned material into the clinical situation. To obtain evidence of the efficacy of e-learning material a certain amount of research has to be done in the near future. It is suggested that all parameters currently known have to be implemented during the development of a learning programme. Previous workers have evaluated the following elements with e-learning: i) planning, ii) programming and technical development, iii) learning behaviours, iv) learning outcomes of both the programme and the student, v) the acquisition of knowledge, skills and attitude and vi) the transfer of e-learned skills into clinical situations.