Canonical correlation analysis between visual evoked responses and biological risk and socioeconomic and demographic factors

Canonical correlation analysis between visual evoked responses and biological risk and socioeconomic and demographic factors

227 CANONICAL CORRELATION ANALYSIS BETWEEN VISUAL EVOKED RESPONSES AND BIOLOGICAL RISK AND SOCIOECONOMIC AND DEMOGRAPHIC FACTORS Thalfa Harmony, Erzse...

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227 CANONICAL CORRELATION ANALYSIS BETWEEN VISUAL EVOKED RESPONSES AND BIOLOGICAL RISK AND SOCIOECONOMIC AND DEMOGRAPHIC FACTORS Thalfa Harmony, Erzsebet Marosi, Jacqueline Becker and Ana E. Dfaz de Leon ENEP-Iztacala, Universidad National Aut6noma de Mexico Knowledge of the effect of developmental, environmental and risk factors associated with brain damage upon VERs may be very useful for future applications of VERs in the evaluation of LD children. VERs were recorded in central, parietal, occipital and posterotemporal leads in 84 children between 6.6 and 12.6 years old. In each VER the amplitude values - sampled each 4 ms - were squared and added to give the power or “energy”. Canonical correlation analyses between VERs energy values and a set of variables taking into consideration different characteristics of the subjects were performed. The most important findings were: VER energy in posterior areas clearly decreased with age, girls had lower energies than boys; low socioeconomic status, antecedents of risk factors and the presence of learning disabilities were associated with lower energy of VERs in parietal leads, the energy in right posterotemporal VERs had a direct relationship with the presence of LD. These results show that all these factors should be taken into account in order to utilize VERs as a routine procedure of evaluation.

MODES OF INFORMATION PROCESSING IN SCHIZOPHRENIC PATIENTS DC- AND ERPMEASURES R. Haschke, K. Peter, M. Tennigkeit, A. Schlichter Ch. Hochmann Departments of Physiology and Psychiatry, Friedrich Schiller University, Jena, G.D.R. One of the reasonable goals of psychophysiological research is to develop objective measures that could aid in diagnostic decision making, understanding the psychological and biological mechanisms involved, determining the fundamental etiology and the development of effective treatment and prevention methods. Schi-

zophrenia is widely considered to be the major unsolved mental health problem. An important question is whether psychophysiological variables can aid in understanding the pervasive deficits in task performance found in schizophrenia. An affirmative answer to this question would imply that these variables reflect underlying processes that also affect performance. Information processing based on neuronal activities is thought to be reflected in DC-shifts as well as in field potentials such as ERPs. The analysis of those potentials during task performance can help to recognize the different elements of this neuronal information processing going on in neuronal masses and distributed in time and space and dependent on a large number of variables including the individual properties. On the basis of the theory of functional systems we were able to define different stages in realization of task performance. The regulation of the more general activation level corresponding to task solution was controlled by DC-recording. The study includes schizophrenic patients which were able to perform a treatment in sense of unspecific or cognitive training. The aim of this study was to prove in an objective manner the treatment effects of the different types of training. There is additional evidence for the determination of the functional state of the c.n.s. during the realization of task performance. In a previous study we established significant differences in the DC-shifts during task performance between healthy, more or less successful subjects performing a task demand. Immediately before task pmsentation we observed a small negative shift especially in the successful subjects. Such a marked negative shift was only to be seen in the case of correct solution of the actual task and a previous positive feedback. In the period between the announcement of the result and the presentation of the feedback signal we found out some differences in the mean potential shapes of the two groups. During the statement of the confidence level the negative slow potential shift was more pronounced in the successful subjects. After the switch off the slide which asks the level of confidence the negative shift was enhanced in the less successful subjects. The differences between the two groups were diminished in the second part of the test period. These data am the basis to describe the regulation of the event-related activation level during realization of a task in healthy subjects.