Modulation of neuronal processing steps of emotional stimuli by task demands
Basic data of the doctoral examination procedure
Doctoral examination procedure finished at: Doctoral examination procedure at University of Münster
Period of time: 01/10/2020 - 04/11/2024
Status: completed
Candidate: Vormbrock, Ria
Doctoral subject: Psychologie
Doctoral degree: Dr. rer. nat.
Form of the doctoral thesis: cumulative
Awarded by: Department 07 - Psychology and Sport Studies
Supervisors: Straube, Thomas; Bölte, Jens; Schindler, Sebastian
Reviewers: Straube, Thomas; Bölte, Jens
Description
Processing of emotional stimuli is prioritised under various attentional conditions. However, the temporal relationship reflected in different event-related potentials (ERPs) of the emotion-attention interaction is unclear. Studies of faces and pictures showed a growing influence of attention on emotional effects in later processing stages. Here, effects of feature-based attention seem to dissociate early from later processing stages, while effects of target relevance seem to modulate late ERP effects. To test whether this pattern also occurs for words, in study 1 negative and neutral words with overlying thin lines were presented while attention was blockwise directed to different features of the stimuli: attention was directed to perceptual features, the word itself, or the emotional content of the word. Results showed the expected pattern: In the early ERPs (P1, N1, P2) no emotional effect occurred, independent of the task. Interactions of emotion and task were found for the Early Posterior Negativity (EPN) and Late Positive Potential (LPP). Specifically, emotional effects in the EPN occurred within the semantic and emotion task. Emotional differences in the LPP were restricted to the emotion task. In line with the results of other visual stimuli, these findings show that emotional differences in mid-latency ERPs require attention to the stimulus, while emotional differences in later, more elaborative processing stages only occur when attention is directed to the emotional content. Contrary to these results there are also studies showing emotional effects even when attention was directed to perceptual features of the stimuli. One difference between the studies with the conflicting findings is the presentation duration of the stimuli. As a result, I varied the presentation duration of fearful and neutral faces, while participants responded to a line-discrimination task in study 2. A main effect of emotion, regardless of presentation duration, was found for the N170, EPN and LPP. These results are in line with theoretical accounts suggesting that emotional processing is independent of processing resources. However, requested explorative tests showed that significant differences in the EPN and LPP only occurred with longer duration and were absent during short durations (100 and 300 ms). However, findings of attention-emotion relationships are so far almost exclusively limited to the visual domain, while theoretical accounts argue that findings apply to all modalities. Therefore, in study 3 two experiments investigated the influence of attention manipulations based on the target relevance of a stimulus on the processing of positive, negative and neutral sounds. In both experiments, participants responded blockwise to one valence. Emotional effects occurred in all processing stages (N1, P1, LPP), while negative sounds were more pronounced in later processing stages. Effects of target relevance were restricted to the early LPP time window in both experiments. These results suggest that emotional processing in the auditory modality is independent of target relevance. In sum, the three studies showed that attentional tasks affect emotional processing at different temporal stages based on task and stimulus modality. The results speak for dissociable emotion processing stages e.g. a possible attention-independent early emotion processing stage. The generalization of theories of the attention-emotion interactions towards auditory stimuli awaits further examination.
Promovend*in an der Universität Münster
Vormbrock, Ria | Institute of Medical Psychology and Neuro Science (IMPS) |
Supervision at the University of Münster
Review at the University of Münster