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     MindNet Journal - Vol. 1, No. 62d * [Part 4 of 4 parts]
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     V E R I C O M M / MindNet         "Quid veritas est?"
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[Continued from part 3]

51. A positive relationship between the P300 and the
consolidation of memory codes (as a typical hippocampal function)
was demonstrated by some of those studies reporting a Dm-effect.
Several studies have shown that ERPs recorded during the encoding
of words (or pictures) that were later remembered were more
positive than ERPs to words (or pictures) that were not
remembered (Sanquist et al., 1980; Karis et al., 1982, 1984;
Johnson, et al., 1985; Neville et al., 1986; Fabiani et al.,
1986; Paller et al., 1987; Fabiani et al., 1990; Friedman, 1990a,
b; and see also the indirect evidence provided by e.g., Noldy et
al., 1990; and the review in Paller, 1993). This difference in
ERPs during encoding which was found within the region of the
typical P300 or a late positive component was termed "Dm" (for
Difference based on later memory performance; Paller et al.,
1987) or Dm-effect. When reviewing this research it is
interesting to see that particularly the P300 does not reflect
the processing of semantic information (i.e., the encoding of a
stimulus per se) but instead the processing of episodic
information. Results reported by Karis et al. (1984) and Fabiani
et al. (1986, 1990) are in good agreement with this
interpretation. They presented subjects with different series of
words which had to be recalled immediately after a list was
presented and found that words later recalled elicited larger
P300s than words not recalled. In addition, Fabiani et al. (1990)
were able to demonstrate that this relationship between the P300
amplitude and episodic memory performance holds only if subjects
use rote learning (which is based on the encoding of contextual
and thus episodic information) but not if subjects use semantic
encoding strategies (such as organizing the words into meaningful
sentences). Thus, the Dm (with respect to the P300) most likely
reflects episodic encoding processes and as a result, this type
of Dm-effect which is based on the P300 component becomes the
weaker; the more semantic encoding processes predominate.

52. Electrophysiological recordings with electrodes implanted in
the hippocampus have not provided clear evidence for the view
that the P300 is generated in the hippocampus (e.g., Polich &
Squire, 1993; and the literature reviewed in this article).
Because theta is generated in the septum and because other parts
of the limbic system also exhibit theta frequency, the crucial
question is, whether or not it can be demonstrated that theta
activity (or the P300) varies as a function of (episodic) memory
performance and that at the same time the hippocampus is involved
in the modification of theta activity (or the P300).

53. An interesting study by Smith and Halgren (1989) who focused
on the word repetition effect in a recognition task provided
evidence for this view. It is well known that old words (repeated
words) elicit a larger P300 than new words (e.g., Sanquist et
al., 1980; and Johnson et al., 1985). Smith and Halgren (1989)
repeated the targets in the recognition task in each of a set of
nine blocks of 20 words (consisting of 10 targets and 10 new
words) and found that the amplitude difference between repeated
and new words did not change with the number of repetitions
(i.e., the number of blocks). Recognition performance, of course,
increased with the number of blocks, but this increase in
performance was not reflected by the amplitude differences
between the repeated and not repeated words which remained
constant with the number of repetitions. Because these results
were found for normal subjects as well as for patients with
unilateral (left or right) anterior temporal lobectomy, it was
concluded that the hippocampus is not involved in the increase of
recognition performance over different blocks, which can be
explained as an increase in implicit memory performance. Most
important, however, the baseline recognition performance was
significantly lower for the patients with a left temporal
lobectomy who from the very beginning also failed to show a
significant P300 amplitude difference between new and old words.
This latter result is consistent with the hypothesis that the
hippocampus (in the dominant left hemisphere) might be capable of
modifying a P300 that reflects explicit, episodic memory
performance.

VII. CONCLUDING REMARKS

54. The main purpose of this article is to encourage an
integrative and interdisciplinary view on memory processes. As a
result of this attempt, new experiments can be performed that
will be capable of critically evaluating the proposed hypotheses.
A promising empirical approach would be to analyze event-related
shifts in EEG power within the theta and alpha bands in amnesic
subjects who perform different types of memory tasks.

55. If it is true that oscillations are the mandatory basis for
information transmission in the cortex and possibly in the entire
brain, a better understanding of the nature of oscillations would
be essential for an integrative view in cognitive neuroscience.
For cognitive psychology this finally would mean to describe
cognitive processes in terms of oscillations and for cognitive
psychophysiology this would mean to focus primarily on the
analysis of certain, carefully selected frequency bands in
addition to the study of event-related potentials.

ACKNOWLEDGEMENTS

This research was supported by the Austrian "Fonds zur Foerderung
der wissenschaftlichen Forschung", Project S-4904 and Project
P-10235.

I wish to thank Stevan Harnad and anonymous reviewers for their
helpful suggestions. In particular, I am grateful for the
insightful critical comments of Niels Birbaumer on an earlier
draft of this manuscript.

REFERENCES

Andersen, P. & Andersson, A.A. (1968). Physiological basis of the
alpha rhythm. New York: Century Crofts.

Anderson, J.R. (1983). A spreading activation theory of memory.
Journal of Verbal Learning and Verbal Behavior, 22, 261-295.

Arnolds, D., Lopes da Silva, F., Aitink, J., Kamp, A. &
Boeijinga, P. (1980). In G. Pfurtscheller & Lopes da Silva
(Eds.), Rhythmic EEG activities and cortical functioning (pp.
91-102). Amsterdam: Elsevier.

Baddeley, A. (1992). Working Memory. Science, 255, 5044, 556-559.

Baddeley, A. (1984). Neuropsychological evidence and the
semantic/ episodic distinction (Commentary to Tulving). The
Behavioral and Brain Sciences, 7, 238-239.

Basar, E. & Bullock, T.H. (Eds.). (1992). Induced rhythms in the
brain. Boston: Birkhaeuser.

Basar, E. & Stampfer, H.G. (1985). Important associations among
EEG-dynamics, event-related potentials, short-term memory and
learning. International Journal of Neuroscience, 26 (3-4),
161-180.

Berger, H. (1929). Ueber das Elektroenkephalogramm des Menschen.
Archiv fuer Psychiatrie und Nervenkrankheiten, 87, 527-570.

Birbaumer, N. & Elbert, Th. (1988). P3: Byproduct of a byproduct.
Behavioral and Brain Sciences, 11(3), 375-377.

Braitenberg, V. & Schuez, A. (1991). Anatomy of the cortex. New
York: Springer Verlag.

Carpenter, G.A. & Grossberg, S. (1993). Normal and amnesic
learning, recognition and memory by a neuronal model of
cortico-hippocampal interactions. TINS, 16, 131-137.

Donchin, E. & Coles, M.G.H. (1988). Is the P300 component a
manifestation of context updating? Behavioral and Brain Sciences,
11, 357-374.

Elbert, T. (1992). A theoretical approach to the late components
of the event-related brain potential. In A. Aertsen & V.
Braitenberg (Eds.). Information processing in the cortex
(225-245). Berlin: Springer Verlag.

Engel, A.K., Koenig, P., Kreiter, A., Schillen, Th. & Singer, W.
(1992). Temporal coding in the visual cortex: new vistas on
integration in the nervous system. TINS, 15(6), 218-226.

Fabiani, M., Karis, D. & Donchin, E. (1986). P300 and recall in
an incidental memory paradigm. Psychophysiology, 23 (3), 298-308.

Fabiani, M., Karis, D. & Donchin, E. (1990). Effects of mnemonic
strategy manipulation in a Von Restorff paradigm.
Electroencephalography and clinical Neurophysiology, 75, 22-35.

Fox, S.E. & Ranck, J.B. Jr. (1981). Electrophysiological
characteristics of hippocampal complex-spike cells and theta
cells. Experimental Brain Research, 41, 399-410.

Freund, T. & Antal, M. (1988). Hippocampal interneurons. Nature,
336, 170-173.

Friedman, D. (1990a). Cognitive event-related potential
components during continuous recognition memory for pictures.
Psychophysiology, 27, 136-148.

Friedman, D. (1990b). ERPs during continuous recognition memory
for words. Biological Psychology, 30, 51-87.

Gray, Ch.M., Koenig, P., Engel, A.K. & Singer, W. (1989).
Oscillatory responses in cat visual cortex exhibit inter-columnar
synchronization which reflects global stimulus properties.
Nature, 338, 335-337.

Gray, C. & Singer, W. (1987). Stimulus-dependent neuronal
oscillations in the cat visual cortex area 17. Neuroscience
(Supplement), 22, 434

Green, J.D. & Arduini, A.A. (1954). Hippocampal electrical
activity in arousal. Journal of Neurophysiology, 17, 533-547.

Greenstein, Y.J., Pavlides, C. & Winson, J. (1988). Long-term
potentiation in the dentate gyrus is preferentially induced at
theta rhythm periodicity. Brain Research, 438, 331-334.

Grossberg, S. (1980). How Does a Brain Build a Cognitive Code?
Psychological Review, 87, 1-51.

Grossberg, S. & Stone, G. (1986). Neuronal Dynamics of Word
Recognition and Recall: Attentional Priming, Learning, and
Resonance. Psychological Review, 93, 46-74.

Hebb, D.O. (1949). The first stage of perception. In D.O. Hebb
(Ed.), The Organization of behavior (pp. 60-78). New York: Wiley.

Hoehl-Abrahao, J.C. & Creutzfeldt, O.D. (1991). Topographical
mapping of the thalamocortical projections in rodents and
comparison with that in primates. Experimental Brain Research,
87, 283-294.

Johnson, R.Jr. (1986). A triarchic model of P300 amplitude.
Psychophysiology, 23, 367-384.

Johnson, R., Pfefferbaum, A. & Kopell, B.S. (1985). P300 and
long-term memory: Latency predicts recognition performance.
Psychophysiology, 22 (5), 497-507.

Karis, D., Bashore, T., Fabiani, M., & Donchin, E. (1982). P300
and memory. Psychophysiology, 19, 328.

Karis, D., Fabiani, M. & Donchin, E. (1984). "P300" and memory:
Individual differences in the von Restorff effect. Cognitive
Psychology, 16, 177-216.

Klimesch, W. (1987). A connectivity model for semantic
processing. Psychological Research, 49, 53-61.

Klimesch, W. (1994). The structure of long-term memory: A
connectivity model of semantic processing. Hillsdale, NJ,
Lawrence Erlbaum.

Klimesch, W., Schimke, H. & Ladurner, G. (1988). Die Suchzeit
fuer episodische und semantische Information. Sprache &
Kognition, 7, 129-143.

Klimesch, W., Schimke, H., Ladurner, G. & Pfurtscheller, G.
(1990). Alpha frequency and memory performance. Journal of
Psychophysiology, 4, 381-390.

Klimesch, W., Schimke, H. & Pfurtscheller, G. (1993). Alpha
frequency, cognitive load and memory performance. Brain
Topography, 5, 1-11.

Klimesch, W., Schimke, H., Doppelmayr, M., Ripper, B., Schwaiger,
J. & Pfurtscheller, G. (1994). Event-related desynchronization
(ERD) and the Dm-effect: Does alpha desynchronization during
encoding predict later recall performance? Submitted paper.

Klimesch, W., Schimke, H. & Schwaiger, J. (1994). Episodic and
semantic memory: An analysis in the theta and alpha band.
Electroencephalography and clinical Neurophysiology, in press.

Koestner, J. (1985). Functional consequences of passive membrane
properties of the neuron. In E.R. Kandel & J.H. Schwartz (Eds.),
Principles of neuronal science (pp. 66-74). New York: Elsevier.

Kroll, N.E.A. & Klimesch, W. (1992). Semantic memory. Complexity
or connectivity? Memory & Cognition, 20, 192- 210.

Larson, J., Wong, D. & Lynch, G. (1986). Patterned stimulation at
the theta frequency is optimal for the induction of hippocampal
long-term potentiation. Brain Research, 368, 347-350.

Lashley, K.S. (1950). In Search of the Engram. Society for
Experimental Biology, Symposium, No. 4, 454-482.

Leung, L. (1980). Behavior-dependent evoked potentials in the
hippocampal CA1 region of the rat. I. Correlation with behavior
and EEG., Brain Research, 198, 95-117.

Lopes da Silva, F.H. (1992). The rhythmic slow activity (theta)
of the limbic cortex: An oscillation in search of a function. In
E. Basar & T.H. Bullock (Eds.), Induced rhythms in the brain (pp.
83-102). Boston: Birkhaeuser.

Lopes da Silva, F.H., Witter, M.P., Boeijinga, P.H. & Lohman,
A.H.M. (1990). Anatomic organization and physiology of the limbic
cortex. Physiological Reviews, 70, 453-511.

Markowitsch, H.J. (1983). Transient global amnesia. Neuroscience
and Biobehavioral Reviews, 7, 35-43.

Markowitsch, H.J. (1984). Can amnesia be caused by damage of a
single brain structure? Cortex, 20, 27-45.

Markowitsch, H.J. & Pritzel, M. (1985). The neuropathology of
amnesia. Progress in Neurobiology, 25, 189-288.

Miller, R. (1991). Cortico-hippocampal interplay and the
representation of contexts in the brain. Berlin: Springer Verlag.

Neville, H.J., Kutas, M., Chesney, G. & Schmidt, A.L. (1986).
Event-related brain potentials during initial encoding and
recognition memory of congruous and incongruous words. Journal of
Memory and Language, 25, 75-92.

Noldy, N.E., Stelmack, R.M. & Campbell, K.B. (1990).
Event-related potentials and recognition memory for pictures and
words: The effects of intentional and incidental learning.
Psychophysiology, 27 (4), 417-428.

Paller, K.A. (1993). Elektrophysiologische Studien zum
menschlichen Gedachtnis. EEG & EMG, 24, 24-33.

Paller, K.A., Kutas, M. & Mayes, A.R. (1987). Neuronal correlates
of encoding in an incidental learning paradigm.
Electroencephalography and clinical Neurophysiology, 67, 360-371.

Petsche, H. & Rappelsberger, P. (1992). Is there any message
hidden in the human EEG? In E. Basar, & T.H. Bullock (Eds.),
Induced rhythms in the brain (pp. 103-116). Boston: Birkhaeuser.

Petsche, H., Stumpf, C. & Gogolak, G. (1962). The significance of
the rabbit's septum as a relay station between the midbrain and
the hippocampus. Electroencephalography and Clinical
Neurophysiology, 19, 25-33.

Pfurtscheller, G. (1992). Event-related synchronization (ERS): an
electrophysiological correlate of cortical areas at rest.
Electroencephalography and clinical Neurophysiology, 83, 62-69.

Pfurtscheller, G. & Klimesch, W. (1991). Event-related
desynchronization during motor behavior and visual information
processing. In C.H.M. Brunia, G. Mulder, & M.N. Verbaten (Eds.),
Event-related brain research (pp. 58-65). Amsterdam: Elsevier.

Pfurtscheller, G. & Klimesch, W. (1992). Functional topography
during a visuoverbal judgment task studied with event-related
desynchronization mapping. Journal of Clinical Neurophysiology,
9, 120-131.

Pfurtscheller, G., Flotzinger, D. & Neuper, Ch. (1994).
Differentiation between finger, toe and tongue movement in man
based on 40-Hz EEG. Electroencephalography and clinical
Neurophysiology, 90, 456-460.

Polich, J. & Squire, L.R. (1993). P300 from amnesic patients with
bilateral hippocampal lesions. Electroencephalography and
clinical Neurophysiology, 86, 408-417.

Pulvermueller, F., Preissl, H., Eulitz, C., Pantev, Ch.,
Lutzenberger, W., Elbert, Th. & Birbaumer, N. (1994). Brain
Rhythms, Cell Assemblies and Cognition: Evidence From the
Processing of Words and Pseudowords. PSYCOLOQUY 5(48)
brain-rhythms.1.pulvermueller.

Sanquist, Th.F., Rohrbaugh, J.W., Syndulko, K. & Lindsley, D.B.
(1980). Electrocortical signs of levels of processing: Perceptual
analysis and recognition memory. Psychophysiology, 17, 568-576.

Scoville, W.B. & Milner, B. (1957). Loss of recent memory after
bilateral hippocampal lesions. Journal of Neurology, Neurosurgery
and Psychiatry, 20, 11-21.

Smith, M.E. & Halgren, E. (1989). Dissociation of Recognition
Memory Components Following Temporal Lobe Lesions. Journal of
Experimental Psychology: Learning, Memory, and Cognition, 15,
50-60.

Squire, L.R. (1992). Memory and the hippocampus: A synthesis from
findings with rats, monkeys, and humans. Psychological Review,
99, 195-231.

Squire, L.R., Knowlton, B. & Musen, G. (1993). The structure and
organization of memory. Annual Review of Psychology, 44, 453-495.

Steriade, M., Jones, E. & Llinas, R. (1990). Thalamic
oscillations and signaling. New York: John Wiley.

Stewart, M. & Fox, S.E. (1990). Do septal neurons pace the
hippocampal theta rhythm? Trends in Neuroscience, 13, 163-168.

Strogatz, St. & Stewart, I. (1993). Coupled oscillators and
biological synchronization. Scientific American, 269(6), 68-75.

Teyler, T.J. & DiScenna, P. (1986). The hippocampal memory
indexing theory. Behavioral Neuroscience, 100, 147-154.

Traub, R., Miles, R. & Wong, R. (1989). Model of the origin of
rhythmic population oscillations in the hippocampal slice.
Science, 243, 1319-1325.

Tulving, E. (1984). Precis of elements of episodic memory. The
Behavioral and Brain Sciences, 7, 223-268.

Vanderwolf, C. & Robinson, T. (1981). Retico-cortical activity
and behavior: A critique of the arousal theory and a new
synthesis. Behavioral and Brain Sciences, 4, 459-514.

Verleger, R. (1988). Event-related potentials and cognition: A
critique of the context updating hypothesis and an alternative
interpretation of P3. Behavioral and Brain Sciences, 11, 343-427.

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