The name is absent

Perspectives of Event-Related Poientiab Research (EEG Suppl. 44)
Editors: G. Kannos, M. Molndr, V. Csepe, I. Czigler and J. E. Desmedt
© 1995 Elsevier Science B.V. All rights reserved

Connections between studies of the neurobiology of attention, psychotic
processes and event-related potentials

Robert D. Oades

RLHK Clinicfor Child and Adolescent Psychiatry, Pf 10 30 43, 45030 Essen (Germany)

My aim in this article is to briefly summarize some
of the biological concomitants of attention, to point
to putative anomalous dysfunctions of these proc-
esses in schizophrenia and to show the relation-
ship between these and what some event-related
potentials (ERPs) may measure.

Attentional schemata

Let us first try to understand the ways in which the
term attention is used. We may distinguish 3 views.
Firstly there is a simple generalization that helps
one focus on the problem (see box, Fig. 1): atten-
tion is ‘the selective aspect of perception’.

The second and third views may be called the
top-down and bottom-up approaches. The top-
down approach represents the application of the
working hypothesis (Fig. 1). It prescribes con-
straints for the measures one can make. The most
important division here is between sustained at-
tention (concentration and vigilance overtime) and
selective attention (allocation of channels for car-
rying information for further processing). At the
bottom of the diagram are various dimensions one
can measure, whose function determines the effi-
cacy of the process.

Correspondence to: R.D. Oades, RLHK. Clinic for Child
and Adolescent Psychiatry, Hufelandstrasse 55, 4300 Essen
1, Germany.

Fig. 1. ‘Top-down’ scheme of attentional operations with ι
selection of contributing and interacting dimensions that can
be experimentally manipulated or measured.

The bottom-up approach represents an attempt
to synthesize an attentional mechanism through an
assembly of the observations of functions, and
hence the operations that have to be taken into ac-
count. Many of these were ably summarized by
Johnston and Dark (1986,Table I). One of the more
enduring metaphors in this work refers to the anal-
ogy of an adjustable beam-spotlight (number 5).

Whichever approach one prefers, we should not
overlook that there are certain spheres of more
general psychobiological function that in practice
affect the way attentional mechanisms perform.

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