- Email: [email protected]
P36.12 Dual route model for recognition of faces and facial expressions: An event-related potential study with spatially filtered images
S302
Posters / Clinical Neurophysiology 117 (2006) S121–S336
Conclusions: The use of tracking ICA can, in principle, allow the separation and analysis of specific brain signals associated with drowsiness. The determination of drowsiness is, however, a complicated task and the specific signals separated by tracking ICA need to be analysed further in conjunction with other measures such as eye movement and the ECG. doi:10.1016/j.clinph.2006.06.621
P36.11 Point correlation dimension (PD2) changes after olfactory and gustatory stimulation T. Ja´rda´nha´zy, A. Ja´rda´nha´zy, J. Tajti, L. Ve´csei University of Szeged, Department of Neurology, Hungary Background: The effects of the smell and taste stimulations are known from functional magnetic resonance imaging (fMRI) and electroencephalographic (EEG) studies. They have shown that the caudal orbitofrontal cortex, amygdala, insular cortex and anterior cingulate are activated by both modalities. Linear EEG investigations in time and frequency domain showed power and coherency changes in the alpha as well as theta bands depending on the quality of the stimulation. Only some analyses of non-linear nature were found. Aim/objective: Of the present study was to investigate the short term effects of an acute smell and taste stimulation in healthy adult volunteers by the PD2 analysis of Skinner and Molnar. Methods: Nine persons (seven females, two males) with an average age of 49 ± 19 years participated in the examination. Sixty seconds of 16 channel EEGs – according to 10/20 system – were recorded by an EEG 16X equipment and digitized by a LI-01/A interface (Mikromed) at a rate of 256 sample/s. After the first 30 s which was taken as a basal period for the comparison a fresh perfume cap or a piece of milk chocolate was presented. The period after the stimulation was divided in two 15 sec long parts and their PD2 results were compared to the basal condition by non-parametric signed rank test of Wilcoxon. Results: it was found that there was a significant decrease in the average of the PD2 after the olfactory stimulation on both sides. A short lasting about 15 s long decrease was found in the F3, O1 and C4 leads. Longer decreases have appeared in the F7, T4, P4 leads and the SD values decreased around the above mentioned positions. The effects after gustatory stimulation were less pronounced and late. Significant decrease of the average PD2 was found only in the right side, on the C4 and O2 leads. Conclusion: it is concluded that the PD2 analysis of the EEGs looks suitable for finding differences in the data processing after olfactory and gustatory stimulation. doi:10.1016/j.clinph.2006.06.622
P36.12 Dual route model for recognition of faces and facial expressions: An event-related potential study with spatially filtered images T. Nakashima 1, Y. Goto 2, T. Abe 3, K. Kaneko 4, T. Saito 1, A. Makinouchi 4, S. Tobimatsu 1 1
Kyushu University, Department of Clinical Neurophysiology, Japan 2 International University of Health and Welfare, Japan 3 Kyushu University, Graduate School of Systems Life Sciences, Japan 4 Kyushu University, Department of Intelligent Systems, Japan Background: Visual information is processed in parallel by the ‘‘magnocellular (M) and parvocellular (P) systems. The former analyzes low-spatial-frequency (LSF) information while the latter processes high-spatial-frequency (HSF) information.’’ However, it remains unclear that how parallel visual channels contribute to recognition of facial perception. Objectives: To clarify the time course for the processing of faces and facial expressions in terms of parallel visual pathways, we studied characteristic changes in event-related potentials (ERPs) to LSF and HSF facial images. Methods: The participants were 13 healthy students. The face stimuli (neutral, anger, fear and happiness) were taken from Japanese and Caucasian Facial Expression of Emotion and Neutral Faces. The cut-off frequencies were <2.5–4.0 cycles/face for LSF and >30.0–50.0 cycles/face for HSF, respectively. ERPs to the face stimuli were recorded from 20 scalp electrodes when the subjects viewed the stimuli presented randomly for 300 ms. Results: The P100 amplitudes at occipital region were significantly enhanced by LSF faces but not by HSF faces. In contrast, the N170 amplitudes in the right hemisphere were significantly augmented by HSF faces but not by LSF faces. In the time windows of 270–310 ms, the significant difference in amplitudes was found for LSF positive vs. LSF negative expressions. However, the significant difference in amplitudes for among negative HSF expressions was observed in the time windows of 330–390 ms. Conclusion: Faces are processed holistically in the early stage (P100) based on LSF information (M-system), before the next stage (N170) analyzes the detailed features of the faces using HSF information (P-system). Consequently, N270-310 discriminates a positive expression from a negative expression depending on LSF information (M-system), and N330-390 then analyzes the difference among negative expressions based on HSF information (P-system). doi:10.1016/j.clinph.2006.06.623
P36.14 Angry face expression induces occipital h and a oscillations B. Gu¨ntekin 1, E. Ba·ar 2
Posters / Clinical Neurophysiology 117 (2006) S121–S336
Conclusions: The use of tracking ICA can, in principle, allow the separation and analysis of specific brain signals associated with drowsiness. The determination of drowsiness is, however, a complicated task and the specific signals separated by tracking ICA need to be analysed further in conjunction with other measures such as eye movement and the ECG. doi:10.1016/j.clinph.2006.06.621
P36.11 Point correlation dimension (PD2) changes after olfactory and gustatory stimulation T. Ja´rda´nha´zy, A. Ja´rda´nha´zy, J. Tajti, L. Ve´csei University of Szeged, Department of Neurology, Hungary Background: The effects of the smell and taste stimulations are known from functional magnetic resonance imaging (fMRI) and electroencephalographic (EEG) studies. They have shown that the caudal orbitofrontal cortex, amygdala, insular cortex and anterior cingulate are activated by both modalities. Linear EEG investigations in time and frequency domain showed power and coherency changes in the alpha as well as theta bands depending on the quality of the stimulation. Only some analyses of non-linear nature were found. Aim/objective: Of the present study was to investigate the short term effects of an acute smell and taste stimulation in healthy adult volunteers by the PD2 analysis of Skinner and Molnar. Methods: Nine persons (seven females, two males) with an average age of 49 ± 19 years participated in the examination. Sixty seconds of 16 channel EEGs – according to 10/20 system – were recorded by an EEG 16X equipment and digitized by a LI-01/A interface (Mikromed) at a rate of 256 sample/s. After the first 30 s which was taken as a basal period for the comparison a fresh perfume cap or a piece of milk chocolate was presented. The period after the stimulation was divided in two 15 sec long parts and their PD2 results were compared to the basal condition by non-parametric signed rank test of Wilcoxon. Results: it was found that there was a significant decrease in the average of the PD2 after the olfactory stimulation on both sides. A short lasting about 15 s long decrease was found in the F3, O1 and C4 leads. Longer decreases have appeared in the F7, T4, P4 leads and the SD values decreased around the above mentioned positions. The effects after gustatory stimulation were less pronounced and late. Significant decrease of the average PD2 was found only in the right side, on the C4 and O2 leads. Conclusion: it is concluded that the PD2 analysis of the EEGs looks suitable for finding differences in the data processing after olfactory and gustatory stimulation. doi:10.1016/j.clinph.2006.06.622
P36.12 Dual route model for recognition of faces and facial expressions: An event-related potential study with spatially filtered images T. Nakashima 1, Y. Goto 2, T. Abe 3, K. Kaneko 4, T. Saito 1, A. Makinouchi 4, S. Tobimatsu 1 1
Kyushu University, Department of Clinical Neurophysiology, Japan 2 International University of Health and Welfare, Japan 3 Kyushu University, Graduate School of Systems Life Sciences, Japan 4 Kyushu University, Department of Intelligent Systems, Japan Background: Visual information is processed in parallel by the ‘‘magnocellular (M) and parvocellular (P) systems. The former analyzes low-spatial-frequency (LSF) information while the latter processes high-spatial-frequency (HSF) information.’’ However, it remains unclear that how parallel visual channels contribute to recognition of facial perception. Objectives: To clarify the time course for the processing of faces and facial expressions in terms of parallel visual pathways, we studied characteristic changes in event-related potentials (ERPs) to LSF and HSF facial images. Methods: The participants were 13 healthy students. The face stimuli (neutral, anger, fear and happiness) were taken from Japanese and Caucasian Facial Expression of Emotion and Neutral Faces. The cut-off frequencies were <2.5–4.0 cycles/face for LSF and >30.0–50.0 cycles/face for HSF, respectively. ERPs to the face stimuli were recorded from 20 scalp electrodes when the subjects viewed the stimuli presented randomly for 300 ms. Results: The P100 amplitudes at occipital region were significantly enhanced by LSF faces but not by HSF faces. In contrast, the N170 amplitudes in the right hemisphere were significantly augmented by HSF faces but not by LSF faces. In the time windows of 270–310 ms, the significant difference in amplitudes was found for LSF positive vs. LSF negative expressions. However, the significant difference in amplitudes for among negative HSF expressions was observed in the time windows of 330–390 ms. Conclusion: Faces are processed holistically in the early stage (P100) based on LSF information (M-system), before the next stage (N170) analyzes the detailed features of the faces using HSF information (P-system). Consequently, N270-310 discriminates a positive expression from a negative expression depending on LSF information (M-system), and N330-390 then analyzes the difference among negative expressions based on HSF information (P-system). doi:10.1016/j.clinph.2006.06.623
P36.14 Angry face expression induces occipital h and a oscillations B. Gu¨ntekin 1, E. Ba·ar 2