Operationalization of the dimensions of a classification of mental functions

Background: So far there has been no empirically proven taxonomy of
mental functions which summarizes brain functions from a
neuropsychological perspective. The classification of mental
functions by Pöppel (1993, 1997) explains the correlation of the
elementary functions from a neuropsychological point of view, based
on a psychology of time. He distinguishes four levels of cognition:
the cognition of simultaneity, of succession, of the subjective
present, and of duration. These levels of cognition are based on
two different brain mechanisms of temporal organization: a
high-frequency mechanism that provides discrete systemic conditions
of 30ms, within which all information that is processed separately
in the brain is synchronized, and a low-frequency mechanism that
summarizes subsequent systemic conditions from 30ms up to a limit
of 3 seconds. Together with the function that provides a certain
level of activation, these two functions form the logistical
functions of the classification of mental functions. They provide
not only the basis of temporal cognition, but also of that which
can be subjectively experienced, i.e., of our perceptions
(representation or perceptual processing of stimuli), memories
(stimulus processing or storage of information), emotions
(evaluation of stimuli), and action, respectively reaction
(response to stimuli). These four domains are the content-related
functions of the classification of mental functions. Objective: The
objective of this paper is to determine to what extent empirical
data collected from a (neuro-) psychological test battery reflect
the representation of the mental functions postulated in theory.
The specific goal is the factor-analytical representation of the
classification of mental functions according to Pöppel (1993, 1997)
by means of the individual tests. Methods: Healthy subjects aged 50
to 65 years without age-associated impairment participated in the
pharmacologically-sponsored clinical study. Based on the theory of
mental functioning, 15 (neuro-) psychological tests were selected
to assess the repertoire of content-related and logistical
functions. Nine tests were selected to assess content-related
functions and six to assess logistical functions. To further test
the dimensionality of Pöppel’s classification, a factor analysis
was conducted to indicate to what extent the measuring instruments
cover the mental functions in Pöppel’s classification. Results: The
content-related function stimulus representation is covered
completely, the function action/reaction is covered by variables in
two out of three tests. The dimension emotional evaluation of
information is largely covered. Temporal reproduction units of