- Email: [email protected]
Semantical and formal effects in ERPs in letter recognition task
where ,Y is the maximum number of independent and different neuron set states, In IV = (12 - I) In(rl - 1): II. is a dimensionless coefficient. approximately equal to 10.0, estimated by the EEG power spectra parameters: A is the number of elements in the stimulus line set (e.g., for Latin letters A = 26). Different values of I’ give a different type of model. We rekealed that boundary values ot r are I and II that corre\pond to different sorts of alphabets (whose elements fill stimulus lines): I’ = II (and f(A) = 1) for the well assimilation alphabets. such as letters or digits: r’ = I (and f(A) = 0) for the scta of elements. which never associated for subject a\ alphilbets before. Actually, our approach in some respect simulates one of the multiple memory systems. implied by E. Tulving (1087) procedural memoq. The equation gives a good correspondence for some operations with the alphabet\. such as addition and multiplication. It was testing on the number of STM hpan data of different authors and with the individual values of II for subject group.
LATERAL HEMISPHERIC ASYMMETRIES (LHA) IN SENILE DEMENTIA OF ALZHEIMER’S TYPE (SDAT) ASSESSED BY I-123 IMP SPECT IMAGING N. Motomura. T. Sea. H. Asaba and T. Sakai Dept. of Neuropsychiat.. Osaka Medical College.
Japan
We assess the frequency of LHA using a I-123 IMP SPECT in SDAT and correlate these asymmetrle\ with clinical parameters such as the duration of illnraa and the severity of dementia. Seventeen right-handed patients fulfilling the criteria of probable Alzheimer disease. according to the NINCDSADRDA. were studied. The patient? w’ere compared with IO healthy right-handed age-matched control subjects. The scvcrit) of the illness wa\ aacesced hy Hasegawa’s dementia rating \ca1e. Significant left/right asymmetric+ (more than 2 S.D. from the controls) were tound by SPECT imaging in 13 out of I7 SDAT patients. Predominance of right hemi$phcre involvrment wa\ oh\erved in 10 out of 1.7 cases. LHA were found in mild ah well as in modcrate or severe cases of SDAT. In this study right hemisphere dysfunction type is more frequent.
ON THE RELATIONSHIP BETWEEN EXPONENT LAW AND SIIORT-TERM Myshkin Yaro&vl
Ivan State University,
TIIE STEVENS’ MEMORY
U.S.S.R
According to the taken hypotheai7 on the phase frequency \lgnal coding proposzl hy I.ehedev A. on the basis of the analysis of individual neurophysioloyic characteristic\. it is poj$ihle to calculate how some elemental? mental processes go on. Theoretical 4culations show that the Stevens‘ power
law is connected with the range of codes of signals presented. The range of codes is determined by character of memory capacity. This assumption was tested by us experimentally. We tested short-term memow capacity, EEG. subjective evaluation of sound tone signals of our subjects applying methods of direct scaling. The analysis of experimental data showed that the Stevens’ power law is connected with a person’s individual psychophysiological characteristics.
MISMATCII NEGATIVITY OF THE BRAIN POTENTIAL (ERP)-CURRENT R. N%itiinen Dept. Psychol.,
Univ. Ilelsinki,
EVENT-RELATED ISSUES
Finland
Mismatch negativity (MMN) is an ERP component which IS specific to stimulus change in a sequence of identical stimuli. MMN seems to be automatically (i.e.. even in the absence of attention) elicited by any physical stimulus change. at least a frequency change. The automatic. pre-conscious discrimination process generating MMN might be of vital significance hy causing an attention switch to a change in some unattended aspect of our auditory environment. Some central issues of the current MNN research will he reviewed and discussed. These include the degree of automaticity (attention independence) of MMN generation and its cerebral generator mechanism,.
SEMANTICAL AND FORMAL LETTER RECOGNITION TASK Z. Njdasdy Institute for Psychology.
EFFECTS
IN ERPs
IN
Ijungary
Ss were watching the pair\ of letter-like tokens which were semantically same (same name) or different and were drawn in bame or different ortography. In the first task the Ss had to make decision whether the tokens were physically same or different. In the second task they were asked if the pair of tokens marked same or different letters. The response time and ERPs were measured. The semantical and ortographical effect\ were indicated hy difference waves between semantically related and unrelated ERPs in two level or ortographical relation. The analyses of latencies of Nl. PI and N2 components give a look inside the early interaction between top-down and hottom-up processe\ of recognition.
SEQUENCING SKILLS AS A FUNC‘TION AI.ITY AND LATERALITY
OF PERSON-
J;inos Nagy, Zsuzsanna Kulcslir and Mriria Nibrhdy Lo&d Eiitviis University. Budapest. Hungary The present study is connected to a research program on predictive vs. interactive motor control (Goldberg. 1985) as a
LATERAL HEMISPHERIC ASYMMETRIES (LHA) IN SENILE DEMENTIA OF ALZHEIMER’S TYPE (SDAT) ASSESSED BY I-123 IMP SPECT IMAGING N. Motomura. T. Sea. H. Asaba and T. Sakai Dept. of Neuropsychiat.. Osaka Medical College.
Japan
We assess the frequency of LHA using a I-123 IMP SPECT in SDAT and correlate these asymmetrle\ with clinical parameters such as the duration of illnraa and the severity of dementia. Seventeen right-handed patients fulfilling the criteria of probable Alzheimer disease. according to the NINCDSADRDA. were studied. The patient? w’ere compared with IO healthy right-handed age-matched control subjects. The scvcrit) of the illness wa\ aacesced hy Hasegawa’s dementia rating \ca1e. Significant left/right asymmetric+ (more than 2 S.D. from the controls) were tound by SPECT imaging in 13 out of I7 SDAT patients. Predominance of right hemi$phcre involvrment wa\ oh\erved in 10 out of 1.7 cases. LHA were found in mild ah well as in modcrate or severe cases of SDAT. In this study right hemisphere dysfunction type is more frequent.
ON THE RELATIONSHIP BETWEEN EXPONENT LAW AND SIIORT-TERM Myshkin Yaro&vl
Ivan State University,
TIIE STEVENS’ MEMORY
U.S.S.R
According to the taken hypotheai7 on the phase frequency \lgnal coding proposzl hy I.ehedev A. on the basis of the analysis of individual neurophysioloyic characteristic\. it is poj$ihle to calculate how some elemental? mental processes go on. Theoretical 4culations show that the Stevens‘ power
law is connected with the range of codes of signals presented. The range of codes is determined by character of memory capacity. This assumption was tested by us experimentally. We tested short-term memow capacity, EEG. subjective evaluation of sound tone signals of our subjects applying methods of direct scaling. The analysis of experimental data showed that the Stevens’ power law is connected with a person’s individual psychophysiological characteristics.
MISMATCII NEGATIVITY OF THE BRAIN POTENTIAL (ERP)-CURRENT R. N%itiinen Dept. Psychol.,
Univ. Ilelsinki,
EVENT-RELATED ISSUES
Finland
Mismatch negativity (MMN) is an ERP component which IS specific to stimulus change in a sequence of identical stimuli. MMN seems to be automatically (i.e.. even in the absence of attention) elicited by any physical stimulus change. at least a frequency change. The automatic. pre-conscious discrimination process generating MMN might be of vital significance hy causing an attention switch to a change in some unattended aspect of our auditory environment. Some central issues of the current MNN research will he reviewed and discussed. These include the degree of automaticity (attention independence) of MMN generation and its cerebral generator mechanism,.
SEMANTICAL AND FORMAL LETTER RECOGNITION TASK Z. Njdasdy Institute for Psychology.
EFFECTS
IN ERPs
IN
Ijungary
Ss were watching the pair\ of letter-like tokens which were semantically same (same name) or different and were drawn in bame or different ortography. In the first task the Ss had to make decision whether the tokens were physically same or different. In the second task they were asked if the pair of tokens marked same or different letters. The response time and ERPs were measured. The semantical and ortographical effect\ were indicated hy difference waves between semantically related and unrelated ERPs in two level or ortographical relation. The analyses of latencies of Nl. PI and N2 components give a look inside the early interaction between top-down and hottom-up processe\ of recognition.
SEQUENCING SKILLS AS A FUNC‘TION AI.ITY AND LATERALITY
OF PERSON-
J;inos Nagy, Zsuzsanna Kulcslir and Mriria Nibrhdy Lo&d Eiitviis University. Budapest. Hungary The present study is connected to a research program on predictive vs. interactive motor control (Goldberg. 1985) as a