I would like to propose a research program to executed during my visiting professorship in 1997-1998 that will build on the accomplishments of the previous visit in 1990-1991 and the subsequent research that I and my students have been pursuing here at my home university, Department of Psychology, Humboldt State University, Arcata, CA. 95521, USA.

What we wanted to investigate in the previous research was the predictive power of slow-negative, DC-potential shifts in the brain's electrical field. Research Question: Are there specific brain changes occurring as the human subject prepares to respond on a difficult perceptual-memory task that will predict whether the subject will respond correctly? We recorded the electroencephalogram of our subjects before, during and after they were responding to the task and noted whether or not their responses on the task were correct or not. One of the major findings of that research was that there was a statistically significant increase in the slow-negative, DC-potential shifts recorded in the frontal and central scalp locations on trials when the subject eventually responded correctly as opposed to the shifts on those trials when the subjects responded incorrectly.

This finding supports our hypothesis that, when a task is a difficult one and requires a somewhat full marshalling of the person's brain resources, an increase in the negative electrical field of the brain in the frontal and central regions is necessary for correct performance. The task was difficult because the stimuli were present only briefly (70 milliseconds) and once presented needed to be retained in memory for 2 seconds and then used as the basis of the subject's response.

At the time there was (and to a certain extent, there still is) a controversy as to whether these slow-negative, DC-potential shifts (termed Bereitschaftspotential - BP - which was initially discovered by Prof. Dr. Lder Deecke) required a motor movement on the part of the subject to take place. Since half of the trials in our studies were initiated by the computer and did not require such responses on the part of the subject, we concluded that no movement was required. Therefore, the significance of the slow-negative, DC-potential shifts is not only preparation of motor movements but also of preparation of tasks in general, motor as well as cognitive.

Also, the slow-negative, DC-potential shifts began 2 seconds before the time predicted by Prof. Deecke's initial research. We concluded that the brain must be engaged in processes other than and in addition to motor movements during these negative shifts. The slow-negative, DC-potential shifts are interpreted to represent the excitatory post- synaptic potentials (EPSPs) that are occurring mostly in the first layer of the neocortex of the brain that underlies the recording electrodes.

One difficulty with this interpretation is that electrical energy spreads through the liquid medium of the brain and so the EPSPs may be occurring in a location some unknown distance from the location of each electrode. Attempts to circumvent this difficulty by using multiple electrodes (64 or 128) and then interpolating among then have been somewhat successful but severe doubt concerning the source of the electrical disturbance still remains.

Recently, the Magnetic Encephalogram (MEG) has become a technique that is useful in exploring brain activity. It is being used in only a few research centers around the world but is recognized as a reliable record of the magnetic activity of the brain before, during and after subject's behavior. Fortunately, the Neurology Clinic of the University of Vienna has developed this technique to the extent that we will be able to record data from over one hundred channels simultaneously while the subject is engaged in a cognitive or motor task.

The advantage of the MEG is that magnetic fields do not spread through the brain as do electrical currents. Therefore, the magnetic disturbances recorded by a particular channel of the MEG will have been generated at the brain location under that channel. The disadvantage of the MEG is that less than half of the brain's activity is recorded by it. Specifically, those fields arising from activity within the sulci are recorded, while those fields arising from the cells and synapses comprising the gyri of the neocortex are not recorded.

By combining the techniques of EEG and MEG in the same subject (either simultaneously recorded or on separate occasions), we can take advantage of the real-time, flow of electrical information from the EEG and the precise localization power of the MEG. Our previous research showed only that the electrodes located over the fronto-central areas of the brain showed maximal slow-negative, DC-potential shifts. Adding the localization power of the MEG will advance our knowledge of the precise locations of the brain's increase in excitatory activity. 1991-1996:

Since my return from Vienna I and my students have pursued this same thread of inquiry. We have now conducted 4 separate experiments, data from which is not fully analyzed, using multiplication mathematical problems as the task rather than a perceptual- memory task. Since our university is small and the magnetic equipment is very expensive, we have been limited to recording the brain's electrical activity with the EEG. In the Fall we will begin 2 studies using a spatial relationship identification task. Later, I envision employing verbal tasks.

This research program is design to test the theory that when the brain is involved in a difficult task at least two kinds of preparation are necessary to insure correct analysis of the problem and accurate behavior. First, there should be a general preparation involved with general arousal, attention to the problem, focused vision on the presentation of the problem, etc. that will be recorded as increased slow-negative, DC-potential shifts in specific locations of the brain over all tasks. Second, there should be a preparation that is specific to the nature of each kind of problem and be located in the part of the brain that is essential for the solution of that kind of problem. This preparation will be recorded as increased slow-negative, DC-potential shifts in locations of the brain different for each kind of task.

The data recorded in MEG indicates the precise (within 2 or 3 mm) location of the source of neuronal brain activity, although not the complete spectrum of neuronal activity as the EEG does. In order to precisely locate this source of activity to a precise location within the brain of each individual subject, Magnetic Resonance Images (MRIs) will be taken of each subject. Through the use of at least three markers, the records of the MRI and of the MEG can be aligned and the exact gyrus or sulcus of the cortex that is the source of the activity identified.

In this new series of studies I propose that we increase the difficulty of the tasks presented to the subjects. Previously we recorded only 9.5% errors on the part of our subjects. It would seem desirable to increase the error rate without instilling in the subjects the sense of inevitable failure.

As a research team we need to decide the following question. Should we present all four of the types of tasks previously mentioned (perceptual-memory, mathematical, spatial relationship and/or verbal tasks) to each and all subjects, should we present one task only to the subjects in separate groups of subjects, or should we concentrate on just one of the tasks this coming year and deal with the others at some future time? Requirements for the study:

Subjects: There are typically a low number of subjects in this type of research since: 1) Each subject will have to be prepared and tested using three different techniques; 2) Subject preparation is very time consuming for both the subjects and the experimenters; 3) The MEG and MRI are expensive procedures; 4) Each technique produces a large amount of data that requires a large investment in computer equipment and expert personnel time. Therefore, the study will require 25 subjects to be tested using the EEG, MEG and MRI techniques.

Equipment: We will require use of the facilities of the University's Neurological Clinic and its EEG, MEG, MRI and computer equipment and personnel.

Scientific Value: This research program and specifically the Vienna portion will address several important scientific problems in our investigation of the brain's control of human behavior.

1) Further explore the strategy which the brain uses to prepare for the solution of difficult problems.

2) Further localize the brain structures responsible for the general and the specific preparation for each type of task,

3) More firmly identify the brain areas involved with motor as opposed to cognitive preparation and the time periods required for each type of preparation,

4) At the end of the research program we may learn enough concerning the brain's organization that would allow us to develop a training program, for example using Biofeedback, with which we could train subjects to prepare their brains in the most effective manner to increase the probability of correct or efficient behavior.

5) The scientific community will also take note of the sophisticated use of these three powerful, non-invasive techniques (MEG, MRI, EEG) employed in combination to address the brain's functioning before, during and after motor and cognitive behavior. 


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