Chrissanthi D Hountala

Publications (4)4.97 Total impact

• Article: Effects of wi-fi signals on the p300 component of event-related potentials during an auditory hayling task.

  Charalabos C Papageorgiou, Chrissanthi D Hountala, Argiro E Maganioti, Miltiades A Kyprianou, Andreas D Rabavilas, George N Papadimitriou, Christos N Capsalis
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  ABSTRACT: The P300 component of event-related potentials (ERPs) is believed to index attention and working memory (WM) operation of the brain. The present study focused on the possible gender-related effects of Wi-Fi (Wireless Fidelity) electromagnetic fields (EMF) on these processes. Fifteen male and fifteen female subjects, matched for age and education level, were investigated while performing a modified version of the Hayling Sentence Completion test adjusted to induce WM. ERPs were recorded at 30 scalp electrodes, both without and with the exposure to a Wi-Fi signal. P300 amplitude values at 18 electrodes were found to be significantly lower in the response inhibition condition than in the response initiation and baseline conditions. Independent of the above effect, within the response inhibition condition there was also a significant gender X radiation interaction effect manifested at 15 leads by decreased P300 amplitudes of males in comparison to female subjects only at the presence of EMF. In conclusion, the present findings suggest that Wi-Fi exposure may exert gender-related alterations on neural activity associated with the amount of attentional resources engaged during a linguistic test adjusted to induce WM.
  Journal of Integrative Neuroscience 06/2011; 10(2):189-202. · 0.76 Impact Factor
• Article: Principal component analysis of the P600 waveform: RF and gender effects.

  Argiro E Maganioti, Chrissanthi D Hountala, Charalambos C Papageorgiou, Miltiades A Kyprianou, Andreas D Rabavilas, Christos N Capsalis
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  ABSTRACT: The aim of the present study was to examine the patterns of activation of the P600 waveform of the event-related potentials (ERP), applying principal component analysis (PCA) and repeated measures ANOVA, and whether these patterns are RF and gender dependent. The ERPs of thirty-nine healthy subjects (20 male and 19 female) were recorded during an auditory memory task in the presence and absence of RF, similar to that emitted by mobile phones. Both PCA and ANOVA produced congruent results, showing that activation of the P600 component occurs early and more intensely in the region of the posterior electrodes and in a less intense manner in the central electrodes. Conversely, the activation at the anterior electrodes arises later with a considerably reduced intensity. In the absence of RF female subjects exhibited significantly lower amplitudes at anterior electrodes and earlier latencies at central electrodes than male subjects. These differences disappear in the presence of RF. Consequently, the P600 component follows distinct patterns of activation in the anterior, central and posterior brain areas and gender differences are observed simultaneously at several electrodes within these areas. Finally, the gender-related functional architecture with regard the P600 component appears to be RF sensitive. In conclusion, the application of the PCA procedure provides an adequate model of the spatially distributed event-related dynamics that correspond to the P600 waveform.
  Neuroscience Letters 06/2010; 478(1):19-23. · 2.11 Impact Factor
• Article: The spectral power coherence of the EEG under different EMF conditions.

  Chrissanthi D Hountala, Argiro E Maganioti, Charalambos C Papageorgiou, Eleni D Nanou, Miltiades A Kyprianou, Vassilis G Tsiafakis, Andreas D Rabavilas, Christos N Capsalis
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  ABSTRACT: The present study introduces the concept of spectral power coherence (SPC), which reflects the pattern of coordination of the four basic EEG bands (delta, theta, alpha, and beta) at a specific location of the brain. The SPC was calculated for the pre-stimulus EEG signal during an auditory memory task under different electromagnetic field (EMF) conditions (900 MHz and 1800 MHz). The results showed that delta rhythm is less consequential in the overall cooperation between the bands than the higher frequency theta, alpha and beta rhythms. Additionally, it has been shown that the radiation effect on SPC is different for the two genders. In the absence of radiation males exhibit higher overall SPC than females. These differences disappear in the presence of 900 MHz and are reversed in the presence of 1800 MHz.
  Neuroscience Letters 09/2008; 441(2):188-92. · 2.11 Impact Factor
• Article: Pre-attentive operation and psychoticism: A P50 event related potential study

  Charalabos Papageorgiou, Ion N. Beratis, Andreas D. Rabavilas, Eleni D. Nanou, Chrissanthi D. Hountala, Argiro E. Maganioti, Christos N. Capsalis, George N. Papadimitriou, Costas N. Stefanis
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  ABSTRACT: On the stipulation that “a theory of personality must be testable” (H. Eysenck), along with the view that the P50 component of the event-related potentials (ERP) indexes pre-attentive operation that reflects thalamocortical and/or reticular activating system (RAS) processes, the present study investigates the association of Eysenck’s personality dimensions, namely psychoticism, extraversion, neuroticism, and lie, with P50 ERP. Sixty volunteers were analyzed (29 males). P50 waveforms were measured through 26 electrode leads during the initiation, inhibition and reproduction condition of the Hayling Sentence Completion test. Extraversion, neuroticism, psychoticism, and lie dimensions were measured by means of the Eysenck Personality Questionnaire. Multivariate analysis of variance revealed that the low psychoticism group had significantly greater amplitudes than the groups with medium and high scores. The differences among the groups reached higher levels of significance in the initiation and the inhibition condition than in the reproduction condition. In the inhibition condition significant differences were located at the frontal leads, whereas in the initiation condition they were scattered throughout the electrode leads. The associations of extraversion, neuroticism and lie scale with P50 were not significant. These results suggest that psychoticism may be related to pre-attentive operation mediated by thalamocortical and/or RAS processes.
  Personality and Individual Differences.