Emotional arousal and stress modulate memory consolidation of visual material
by Prof. Dr. Oliver T. Wolf
Not all visual stimuli which we perceive on a daily basis are stored in our memory. One major determinate is attention, leading to a selection of stimuli to be further processed. However in addition to factors which influence the initial encoding of visual stimuli research over the years has established that events occurring after the initial encoding process can modulate the probability of a later retrieval success. It is thought that these influences act on the process of memory consolidation, which can be defined as the stabilization of a memory trace after the initial acquisition. Neuroscientific research has helped us to understand these modulating factors. In my talk I will focus on the influence of emotional arousal and stress on long-term memory consolidation. Research from my own laboratory using experimental behavioural paradigms as well as neuroimaging paradigms will be presented in order to provide examples for the enhancing effect of stress on memory consolidation. These findings support the hypothesis that the amygdala, a small structure in the limbic region of the brain, modulates memory consolidation in other brain regions (e.g. in the hippocampus in the case of explicit long term memory). The model explains how stress via hormonal signals leads to an enhanced memory consolidation of emotionally relevant visual material. It is conceptualized that this process is adaptive enabling the organism to perform more effective in future stressful situations. The findings illustrate that depending on the emotional state of the organism the same visual input can lead to memories traces which differ in their strength.