Early Left-Hemispheric Dysfunction of Face Processing in Congenital Prosopagnosia: An MEG Study

Electrophysiological research has demonstrated the relevance to face processing of a negative deflection peaking around 170 ms, labelled accordingly as N170 in the electroencephalogram (EEG) and M170 in magnetoencephalography (MEG). The M170 was shown to be sensitive to the inversion of faces and to familiarity-two factors that are assumed to be crucial for congenital prosopagnosia. In order to locate the cognitive dysfunction and its neural correlates, we investigated the time course of neural activity in response to these manipulations.Seven individuals with congenital prosopagnosia and seven matched controls participated in the experiment. To explore brain activity with high accuracy in time, we recorded evoked magnetic fields (275 channel whole head MEG) while participants were looking at faces differing in familiarity (famous vs. unknown) and orientation (upright vs. inverted). The underlying neural sources were estimated by means of the least square minimum-norm-estimation (L2-MNE) approach.The behavioural data corroborate earlier findings on impaired configural processing in congenital prosopagnosia. For the M170, the overall results replicated earlier findings, with larger occipito-temporal brain responses to inverted than upright faces, and more right- than left-hemispheric activity. Compared to controls, participants with congenital prosopagnosia displayed a general decrease in brain activity, primarily over left occipitotemporal areas. This attenuation did not interact with familiarity or orientation.The study substantiates the finding of an early involvement of the left hemisphere in symptoms of prosopagnosia. This might be related to an efficient and overused featural processing strategy which serves as a compensation of impaired configural processing

Migrating business software applications based on IGS (Inova Q Generator System) from Windows/VB to Linux/Java

Zsfassung in dt. SpracheIn den letzten Jahren ist vor allem im Bereich der öffentlichen Verwaltung und Behörden die Nachfrage nach Open Source Lösungen gestiegen. Dies stellt an die in diesem Umfeld tätigen IT-UnternehmenIn the last years the demand for Open Source solutions increased considerably, especially in the area of public management and authorities. Resulting from this, IT enterprises active in this business segment either have to provide new platform independent products or migrate already existing ones. This thesis deals with the migration of an existing system that generates software applications.The generated database applications get the needed data from an SQL database, are written in Visual Studio, and run on a Microsoft operating system. The challenge to the migration process consists in transferring this "monoculture" of well coordinated components into an open system.Outgoing from an analysis of the available technologies in the area of software migration and reengineering we try to adapt the generator in order to generate Java programs executable on Linux. The resulting application must be equivalent in appearance, behaviour, and functionality. The chosen migration approach and the problems and inadequacies arising hereby are documented and evaluated.12

Figure 1

<p>Left and right: Global Power of Minimum Norm Estimates separated by hemisphere, groups and conditions. Top middle: Sensors groups (red circles) selected for the analysis of brain responses regarding the M170 projected onto a standard brain model.</p

Mapping of Minimum Norm Estimates for the time interval of the M170 (displayed in an early and a late interval) separated by groups and conditions.

<p>Mapping of Minimum Norm Estimates for the time interval of the M170 (displayed in an early and a late interval) separated by groups and conditions.</p

A fast neural signature of motivated attention to consumer goods separates the sexes

Emotional stimuli guide selective visual attention and receive enhanced processing. Previous event-related potential studies have identified an early (>120 ms) negative potential shift over occipito-temporal regions (early posterior negativity, EPN) presumed to indicate the facilitated processing of survival-relevant stimuli. The present study investigated whether this neural signature of motivated attention is also responsive to the intrinsic significance of man-made objects and consumer goods. To address this issue, we capitalized on gender differences towards specific man-made objects, shoes and motorcycles, for which the Statistical Yearbook 2005 of Germany’s Federal Statistical Office (Statistisches Bundesamt, 2005) revealed pronounced differences in consumer behavior. In a passive viewing paradigm, male and female participants viewed pictures of motorcycles and shoes, while their magnetoencephalographic brain responses were measured. Source localization of the magnetic counterpart of the EPN (EPNm) revealed pronounced gender differences in picture processing. Specifically, between 130 and 180 ms, all female participants generated stronger activity in occipito-temporal regions when viewing shoes compared to motorcycles, while all men except one showed stronger activation for motorcycles than shoes. Thus, the EPNm allowed a sex-dimorphic classification of the processing of consumer goods. Self-report data confirmed gender differences in consumer behavior, which, however, were less distinct compared to the brain based measure. Considering the latency of the EPNm, the reflected automatic emotional network activity is most likely not yet affected by higher cognitive functions such as response strategies or social expectancy. Non-invasive functional neuroimaging measures of early brain activity may thus serve as objective measure for individual preferences towards consumer goods

Time course of activity for the M170 averaged across conditions and displayed separately for groups and hemispheres (error bars represent one standard error).

<p>Time course of activity for the M170 averaged across conditions and displayed separately for groups and hemispheres (error bars represent one standard error).</p

Number of correct behavioural responses in all conditions and laterality index

<p>Number of correct behavioural responses in all conditions and laterality index</p