Acute stress is a stereotypical, but multimodal response to a present or
imminent challenge overcharging an organism. Among the different branches of
this multimodal response, the consequences of glucocorticoid secretion have
been extensively investigated, mostly in connection with long-term memory
(LTM). However, stress responses comprise other endocrine signaling and
altered neuronal activity wholly independent of pituitary regulation. To
date, knowledge of the impact of such “paracorticoidal” stress
responses on higher cognitive functions is scarce.
We investigated the impact of an ecological stressor on the ability to direct
selective attention using event-related potentials in humans. Based on
research in rodents, we assumed that a stress-induced imbalance of
catecholaminergic transmission would impair this ability.
The stressor consisted of a single cold pressor test. Auditory negative
difference (Nd) and mismatch negativity (MMN) were recorded in a tonal
dichotic listening task. A time series of such tasks confirmed an increased
distractibility occuring 4–7 minutes after onset of the stressor as
reflected by an attenuated Nd. Salivary cortisol began to rise 8–11
minutes after onset when no further modulations in the event-related
potentials (ERP) occurred, thus precluding a causal relationship.
This effect may be attributed to a stress-induced activation of mesofrontal
dopaminergic projections. It may also be attributed to an activation of
noradrenergic projections. Known characteristics of the modulation of ERP by
different stress-related ligands were used for further disambiguation of
causality. The conjuncture of an attenuated Nd and an increased MMN might be
interpreted as indicating a dopaminergic influence. The selective effect on
the late portion of the Nd provides another tentative clue for this.
Prior studies have deliberately tracked the adrenocortical influence on
cognition, as it has proven most influential with respect to LTM. However,
current cortisol-optimized study designs would have failed to detect the
present findings regarding attention.
Publisher: Public Library of Science
Date Published: 5-April-2011
Author(s): Elling L., Steinberg C., Bröckelmann A., Dobel C., Bölte J., Junghofer M.