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604 Theta rhythm of infant EEG and the development of the executive control of attention
Abstracts
/International
Journal
nation of left hemisphere, and another two revealed more complex spatial pattern of activity. Both loads hadn’t changed correlation dimension map of any subject significantly. So we may conclude, that alert relaxation state map of every individual person remains stable under elementary mental and physiological loads.
602 A NEW APPROACH TO ASSESSING DROWSINESS AND ATTENTION THROUGH CONTINUOUS EEG (CEEG) AND NEURAL NETWORK METHODS
C. Alford, R. Everson, K. Hapeshi, S. Roberts, H. Stone and S. Wilson British Aerospace, Sowerby Research Centre, Bristol, UK The electrophysiological evaluation of sleep has been standardised for 30 years (Rechtschaffen and Kales, 1968) differentiating 5 sleep stages and waking. Levels of attention and performance, including lapses, are known to vary with levels of EEG arousal during waking (Carskadon and Dement, 1979) although a formal ‘staging’ system has not been established. Current work represents a novel approach to the automated detection of arousal through neural net and related signal processing techniques. A staging system for waking, has been developed (Alford et al., 1992) based on continuous digital ambulatory monitoring (C-EEG), which is both compatible and continuous with standard sleep measures (EEG, EOG, EMG). Continuous ambulatory monitoring (C-EEG) discriminates waking into 6 levels from ‘active’ to intermittent theta reflecting drowsiness and incipient sleep. With this visual analysis, based on Medilog MR95 recordings (13 bit, 256 Hz), 15 second epochs are scored for waking (or sleep) level. These data are also analysed using neural net and signal processing techniques to determine whether there exists a correlation between measures derived from biological signals and task-related observer performance. C-EEG measures are used to discern patterns of activity for use in verification of the approach and for use with supervised learning approaches. Different levels of task performance have been assessed through different task combinations: compensatory tracking, reaction time and short term memory. Performance data were time-locked to the physiological recordings. Video recording and subjective response provide additional data. Signal processing methods are being used to correlate EEG data with task performance including the prediction of state changes. Preliminary analysis shows a rhythmic cycling (period - 5 min) in both task performance and the spatio-temporal complexity of the EEG signal. Furthermore, EEG signal complexity and task performance are found to be correlated, permitting prediction of performance from EEG. Future aims include the development of on-line monitoring for use in transport systems.
of Psychophysiology
30 (1998)
603 THE MANIFESTATION TASIES IN THE PUPIL Erkki Huhmar Rannikkoldivurintie
229
95-271
OF HOMOEROTIC
FAN-
15, Helsinki, Finland
Hess has described how the pupil reacts to various feelings (Scientific American. Contemporary Psychology 1971). According to him, the dilatation of the pupil suggests emotional interest. If a homosexual male is shown erotic pictures, the reactions are stronger in the case of masculine pictures. The subject of the pupil measuring was an academic middle-aged man, married with children, social and respected at his working place. He had a suffocating fear of being regarded as homosexual although he did not consider himself to be one at all. The magnitude of the fear manifests itself in his threat to commit suicide if he cannot substantiate his heterosexuality. He was not considered homosexual by his fellow workers. In the pupil registration the subject looks through zoom binoculars. In front of the ocular there are small infrared lamps lighting the eye. The binoculars are connected with a TV-camera with a tele-objective. The picture of the pupil on the monitor was filmed twice in a second, and the size of the pupil measured. The test pictures were given through the other half of the binoculars. The test was carried out by showing the subject 15 masculine and 15 feminine pictures including nudes, pictures of faces, genitals and intercourse. As a curiosity, there were also exaggerated and grotesque drawings from a world-wide homosexual magazine. There was no reaction to these pictures. He had five clearly positive reactions to the male pictures and only one to the feminine pictures. Is it possible to link his clinical status to the pupil findings? The psychiatric evaluation suggests latent homosexuality. My opinion is that he was not openly homosexual but had profuse homoerotic fantasies. A normal person considers himself capable of hiding his intimate fantasies from his environment. Since the subject felt he was regarded as homosexual, he was not able to protect his privacy in a healthy way.
604 THETA RHYTHM OF INFANT EEG AND THE DEVELOPMENT OF THE EXECUTIVE CONTROL OF ATTENTION T.A. Stroganova’*, E.V. Orekhtova’, I.N. Posikera’ ‘Brain Research Institute RAMS, Per. Obukha, 5, Moscow, 103064 Russia ‘Psychological Institute RAE, Moscow, Russia The neurophysiological basis of attention control has been investigated in infants during the second half of the first year of life. It is known, that the marked improvement of voluntary control of attention and action occurs during this age period. EEG was registered in 60 infants aged 8-11 months under three experimental conditions: 1) attention to an object in the
230
Abstracts
/International
Journal
of Psychophysiology300
visual field (externally controlled attention or the :‘baseline”); 2) anticipation of the person in the peek-a-boo game (internally controlled attention); 3) attention to the “reappeared” person in the peek-a-boo game (“control” condition). Spectral analysis of the data revealed sharp increase of the EEG theta activity (3.6-6.0 Hz) during internally controlled attention as compared to the “baseline” and the “control” conditions. The 01 (3.6-4.8 Hz) increase was maximal at frontal derivations. The reactivity of the frontal 81 during internally controlled attention differentiated subjects with different ability to maintain this type of attention. The 02 (5.2-6.0 Hz) reactivity was maximal at right temporal derivation (T6) and did not depend on the ability to maintain anticipatory attention. The data point to different functional significance of 61 and 02 rhythms in infants. It was suggested that the frontal 61 synchronisation in infants reflects activity of the anterior attention system subserving executive control of attention. The ability to maintain anticipatory attention increased with age, whereas the frontal 01 synchronisation decreased during this age period. There was the direct relationship between frontal 01 synchronisation and persistence of internally controlled attention in 8 month-olds. At 9 and 10 months, on the contrary, these’> variables were inversely related. It was suggested that age-dependant dynamic of the relationship between frontal 01 reactivity and attention behaviour reflects the maturational shift in the development of anterior attention system. The shift appears as more economic, but more efficient functioning of this system. P 605 EFFECTS OF CONTEXT ON ERPs ELICITED BY GO AND NO GO STIMULI IN A 3STIMULUS PARADIGM R.C. Howard*, K.B. Chua, P. McCullough, P. Gent, G. McAllister Dept. of Social Work and Psychology, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Republic of Singapore This study. investigated the influence of task demands (Go vs. No Go) of a third visual stimulus (S3) which occurred infrequently (Py 0.1) in the context of a task where occasional targets (Py 0.1) must be discriminated from common nontargets (Py 0.8). This discrimination was either easy (vertical line vs. line tilted 45 degrees from the vertical) or difficult (vertical line vs. line tilted 1.5 degrees from the vertical). S3 was a line 45 degrees from the vertical but oriented in the other direction. ERPs were recorded in 16 healthy young males from Fpz, Fz, Cz and Pz using Ag/AgCl electrodes referred to linked mastoids, with gain set at XSOK and bandpass at 0.01-30 Hz. Averages (24 sweeps per average) were formed separately for targets and ST, for each channel. Maximum positivity was measured with reference to baseline during 2 time windows: 250-400 ms (“early P3”) and 400-650 ms (“late P3”) post-stimulus. Results showed that: 1) When S3
(1998)
95-271
signalled Go, it evoked a significantly larger late P3 than when it signalled No Go; 2) The P3 elicited by targets was of significantly larger amplitude and shorter latency when the discrimination was difficult compared to the easy condition; 3) Contextual (task difficulty) effects were apparent for both early and late P3s evoked by S3. For early P3, context interacted with response requirement (Go vs. No Go) of S3; 4) Both target P3 and P3 to S3 were maximal parietally: there was no evidence of a frontally dominant P3a. However, whereas the P3 evoked by Go S3 was of longest latency parietally, that evoked by No Go S3 was of longer latency frontally.
606 LATERALITY AND SEX FACTORS PROCESSES OF SELECTIVE ATTENTION
ROLE
IN
L.V. Loskutova*, N.V. Volf, S.A. Golosheikin Institute of Physiology of Siberian Branch of Russian Academy of Medical Sciences, Timakov str., 4, Novosirizsk, 630117, Russia
In recent years there has been a convergence of evidence suggesting hemispheric differences in maintenance of attention. Inhibition or ignoring of irrelevant information is significant aspect of attentional processes. Latent inhibition (LI) paradigm is shown to be effective way to study inhibitory mechanism of attention. Hemispheric organization of LI is not known. The data were obtained in animal and human subjects. New original procedure has been developed to study LI in human subjects. In preexposure phase humans were presented with pair to be compared letters in the right or left visual hemifield. The preexposed group, engaged in masking task, was presented with a number of trials in which nonattened target stimulus appeared in the one visual hemifield (in the right for the one half of the group and in the left for another). In humans the LI effect was more pronounced after preexposure to-be-conditioned stimulus in the left visual hemifield compared to right one. In LI paradigms it was difficult to produce inhibitory effects of preexposure with women whereas men demonstrated strong LI effect. The analysis of LI phenomenon in the one-trial inhibitory passive avoidance task in Wistar rats indicated the same sex differences. Furthermore, these behavioral sex differences were accompanied by specific neurochemical changes in the preexposure phase. The serotonergic activation was found in the n. accumbens. Left-right asymmetry in the serotonin content of accumbens was found only in male rats. Serotonin and 5-hydroqindole-3acetic acid contents were higher in the right side than in the left one. Thus, our findings suggest: (1) asymmetrical hemispheric regulation, right cerebral specialization for LI (2) sex differences in this phenomenon (3) interactions with serotonin metabolism.
/International
Journal
nation of left hemisphere, and another two revealed more complex spatial pattern of activity. Both loads hadn’t changed correlation dimension map of any subject significantly. So we may conclude, that alert relaxation state map of every individual person remains stable under elementary mental and physiological loads.
602 A NEW APPROACH TO ASSESSING DROWSINESS AND ATTENTION THROUGH CONTINUOUS EEG (CEEG) AND NEURAL NETWORK METHODS
C. Alford, R. Everson, K. Hapeshi, S. Roberts, H. Stone and S. Wilson British Aerospace, Sowerby Research Centre, Bristol, UK The electrophysiological evaluation of sleep has been standardised for 30 years (Rechtschaffen and Kales, 1968) differentiating 5 sleep stages and waking. Levels of attention and performance, including lapses, are known to vary with levels of EEG arousal during waking (Carskadon and Dement, 1979) although a formal ‘staging’ system has not been established. Current work represents a novel approach to the automated detection of arousal through neural net and related signal processing techniques. A staging system for waking, has been developed (Alford et al., 1992) based on continuous digital ambulatory monitoring (C-EEG), which is both compatible and continuous with standard sleep measures (EEG, EOG, EMG). Continuous ambulatory monitoring (C-EEG) discriminates waking into 6 levels from ‘active’ to intermittent theta reflecting drowsiness and incipient sleep. With this visual analysis, based on Medilog MR95 recordings (13 bit, 256 Hz), 15 second epochs are scored for waking (or sleep) level. These data are also analysed using neural net and signal processing techniques to determine whether there exists a correlation between measures derived from biological signals and task-related observer performance. C-EEG measures are used to discern patterns of activity for use in verification of the approach and for use with supervised learning approaches. Different levels of task performance have been assessed through different task combinations: compensatory tracking, reaction time and short term memory. Performance data were time-locked to the physiological recordings. Video recording and subjective response provide additional data. Signal processing methods are being used to correlate EEG data with task performance including the prediction of state changes. Preliminary analysis shows a rhythmic cycling (period - 5 min) in both task performance and the spatio-temporal complexity of the EEG signal. Furthermore, EEG signal complexity and task performance are found to be correlated, permitting prediction of performance from EEG. Future aims include the development of on-line monitoring for use in transport systems.
of Psychophysiology
30 (1998)
603 THE MANIFESTATION TASIES IN THE PUPIL Erkki Huhmar Rannikkoldivurintie
229
95-271
OF HOMOEROTIC
FAN-
15, Helsinki, Finland
Hess has described how the pupil reacts to various feelings (Scientific American. Contemporary Psychology 1971). According to him, the dilatation of the pupil suggests emotional interest. If a homosexual male is shown erotic pictures, the reactions are stronger in the case of masculine pictures. The subject of the pupil measuring was an academic middle-aged man, married with children, social and respected at his working place. He had a suffocating fear of being regarded as homosexual although he did not consider himself to be one at all. The magnitude of the fear manifests itself in his threat to commit suicide if he cannot substantiate his heterosexuality. He was not considered homosexual by his fellow workers. In the pupil registration the subject looks through zoom binoculars. In front of the ocular there are small infrared lamps lighting the eye. The binoculars are connected with a TV-camera with a tele-objective. The picture of the pupil on the monitor was filmed twice in a second, and the size of the pupil measured. The test pictures were given through the other half of the binoculars. The test was carried out by showing the subject 15 masculine and 15 feminine pictures including nudes, pictures of faces, genitals and intercourse. As a curiosity, there were also exaggerated and grotesque drawings from a world-wide homosexual magazine. There was no reaction to these pictures. He had five clearly positive reactions to the male pictures and only one to the feminine pictures. Is it possible to link his clinical status to the pupil findings? The psychiatric evaluation suggests latent homosexuality. My opinion is that he was not openly homosexual but had profuse homoerotic fantasies. A normal person considers himself capable of hiding his intimate fantasies from his environment. Since the subject felt he was regarded as homosexual, he was not able to protect his privacy in a healthy way.
604 THETA RHYTHM OF INFANT EEG AND THE DEVELOPMENT OF THE EXECUTIVE CONTROL OF ATTENTION T.A. Stroganova’*, E.V. Orekhtova’, I.N. Posikera’ ‘Brain Research Institute RAMS, Per. Obukha, 5, Moscow, 103064 Russia ‘Psychological Institute RAE, Moscow, Russia The neurophysiological basis of attention control has been investigated in infants during the second half of the first year of life. It is known, that the marked improvement of voluntary control of attention and action occurs during this age period. EEG was registered in 60 infants aged 8-11 months under three experimental conditions: 1) attention to an object in the
230
Abstracts
/International
Journal
of Psychophysiology300
visual field (externally controlled attention or the :‘baseline”); 2) anticipation of the person in the peek-a-boo game (internally controlled attention); 3) attention to the “reappeared” person in the peek-a-boo game (“control” condition). Spectral analysis of the data revealed sharp increase of the EEG theta activity (3.6-6.0 Hz) during internally controlled attention as compared to the “baseline” and the “control” conditions. The 01 (3.6-4.8 Hz) increase was maximal at frontal derivations. The reactivity of the frontal 81 during internally controlled attention differentiated subjects with different ability to maintain this type of attention. The 02 (5.2-6.0 Hz) reactivity was maximal at right temporal derivation (T6) and did not depend on the ability to maintain anticipatory attention. The data point to different functional significance of 61 and 02 rhythms in infants. It was suggested that the frontal 61 synchronisation in infants reflects activity of the anterior attention system subserving executive control of attention. The ability to maintain anticipatory attention increased with age, whereas the frontal 01 synchronisation decreased during this age period. There was the direct relationship between frontal 01 synchronisation and persistence of internally controlled attention in 8 month-olds. At 9 and 10 months, on the contrary, these’> variables were inversely related. It was suggested that age-dependant dynamic of the relationship between frontal 01 reactivity and attention behaviour reflects the maturational shift in the development of anterior attention system. The shift appears as more economic, but more efficient functioning of this system. P 605 EFFECTS OF CONTEXT ON ERPs ELICITED BY GO AND NO GO STIMULI IN A 3STIMULUS PARADIGM R.C. Howard*, K.B. Chua, P. McCullough, P. Gent, G. McAllister Dept. of Social Work and Psychology, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Republic of Singapore This study. investigated the influence of task demands (Go vs. No Go) of a third visual stimulus (S3) which occurred infrequently (Py 0.1) in the context of a task where occasional targets (Py 0.1) must be discriminated from common nontargets (Py 0.8). This discrimination was either easy (vertical line vs. line tilted 45 degrees from the vertical) or difficult (vertical line vs. line tilted 1.5 degrees from the vertical). S3 was a line 45 degrees from the vertical but oriented in the other direction. ERPs were recorded in 16 healthy young males from Fpz, Fz, Cz and Pz using Ag/AgCl electrodes referred to linked mastoids, with gain set at XSOK and bandpass at 0.01-30 Hz. Averages (24 sweeps per average) were formed separately for targets and ST, for each channel. Maximum positivity was measured with reference to baseline during 2 time windows: 250-400 ms (“early P3”) and 400-650 ms (“late P3”) post-stimulus. Results showed that: 1) When S3
(1998)
95-271
signalled Go, it evoked a significantly larger late P3 than when it signalled No Go; 2) The P3 elicited by targets was of significantly larger amplitude and shorter latency when the discrimination was difficult compared to the easy condition; 3) Contextual (task difficulty) effects were apparent for both early and late P3s evoked by S3. For early P3, context interacted with response requirement (Go vs. No Go) of S3; 4) Both target P3 and P3 to S3 were maximal parietally: there was no evidence of a frontally dominant P3a. However, whereas the P3 evoked by Go S3 was of longest latency parietally, that evoked by No Go S3 was of longer latency frontally.
606 LATERALITY AND SEX FACTORS PROCESSES OF SELECTIVE ATTENTION
ROLE
IN
L.V. Loskutova*, N.V. Volf, S.A. Golosheikin Institute of Physiology of Siberian Branch of Russian Academy of Medical Sciences, Timakov str., 4, Novosirizsk, 630117, Russia
In recent years there has been a convergence of evidence suggesting hemispheric differences in maintenance of attention. Inhibition or ignoring of irrelevant information is significant aspect of attentional processes. Latent inhibition (LI) paradigm is shown to be effective way to study inhibitory mechanism of attention. Hemispheric organization of LI is not known. The data were obtained in animal and human subjects. New original procedure has been developed to study LI in human subjects. In preexposure phase humans were presented with pair to be compared letters in the right or left visual hemifield. The preexposed group, engaged in masking task, was presented with a number of trials in which nonattened target stimulus appeared in the one visual hemifield (in the right for the one half of the group and in the left for another). In humans the LI effect was more pronounced after preexposure to-be-conditioned stimulus in the left visual hemifield compared to right one. In LI paradigms it was difficult to produce inhibitory effects of preexposure with women whereas men demonstrated strong LI effect. The analysis of LI phenomenon in the one-trial inhibitory passive avoidance task in Wistar rats indicated the same sex differences. Furthermore, these behavioral sex differences were accompanied by specific neurochemical changes in the preexposure phase. The serotonergic activation was found in the n. accumbens. Left-right asymmetry in the serotonin content of accumbens was found only in male rats. Serotonin and 5-hydroqindole-3acetic acid contents were higher in the right side than in the left one. Thus, our findings suggest: (1) asymmetrical hemispheric regulation, right cerebral specialization for LI (2) sex differences in this phenomenon (3) interactions with serotonin metabolism.