Current Research Projects
In the following, current and planned research projects of our team are listed in a numbered fashion. The numbering does not give any information about the temporal order or priority of the studies.
1. Neuro-cognitive mechanisms of episodic encoding of items and associations
Behavioral data, neuroimaging studies and patient studies suggest that the neuro-cognitive processes that are responsible for episodic encoding of associations between stimuli differ from those that are used to encode item details. In this research project, we investigate whether such a distinction is also evident in event-related potentials (ERPs). To this end, we use the "subsequent memory" analysis strategy: ERP activity during a learning task is calculated separately for material that is successfully retrieved in a subsequent test on the one hand, and for material that is forgotten on the other hand. Initial evidence from this project suggests that a parietally distributed ERP "subsequent memory effect" (SME) reflects episodic encoding of item details, while a somewhat later, frontally distributed SME is an index for encoding of associations.
See also:
Kamp, S.-M., Bader, R., & Mecklinger, A. (2017). ERP subsequent memory effects differ between inter-item and unitization encoding tasks. Frontiers in Human Neuroscience, 11, 30.
2. Combining ERPs with cognitive modeling to develop of an integrated model of episodic encoding
There are different strategies to investigate how episodic memory works. One strategy involves the development of a theoretical, mechanistic model, the derivation and testing of hyotheses for behavioral patterns in memory tests, and cognitive modeling of these behavioral patterns. Another strategy is to develop hypotheses based on previous knowledge on brain activity that reflects different encoding mechanisms. In order to gain a deeper understanding of episodic encoding and to develop an integrated model, we combine the two strategies in this project.
See also:
Kamp, S.-M., Lehman, M., Malmberg, K. J. & Donchin, E. (2016). A buffer model account of behavioral and ERP patterns in the Von Restorff paradigm. AIMS Neuroscience, 3(2), 181-202.
3. Episodic encoding of items and associations: Changes during aging
There are many research studies that confirm our intuition about changes of episodic memory in older age: performance in memory test generally declines during aging. Perhaps less intuitive is the idea that there are differences in the decline between different types of episodic memory. In specific, aging differentially affects the ability to memorize and retrieve individual stimuli (e.g., a name) vs. new associations between stimuli (e.g., which name belongs to which face). The first goal of this project is to study the neuro-cognitive mechanisms that form the basis for this relatively large but selective decline in only some aspects of episodic memory during aging. Secondly, we try to develop strategies and recommendations that may help older adultsto counteract the episodic memory decline.
See also:
Kamp, S.-M., & Zimmer, H. D. (2015). Contributions of attention and elaboration to associative encoding in young and older adults. Neuropsychologia, 15, 252-264.
Kamp, S.-M., Bader, R., & Mecklinger, A. (2018). Untization of word pairs in young and older adults: Encoding mechanisms and retrieval outcomes. Psychology and Aging, 33(3), 497-511.
AnFAnG-Studie (in German)
4. Encoding of items and associations under stress
Stress immediately before or during a typical episodic learning task influences how well we remember the learned information later on. It is, however, unclear wether learning of items and associations is affected equally strongly. On the one hand, effects of stress on learning may be due to a modulation of hippocampal activity, which, in turn, is particular important for the encoding of arbitrary associations. On the other hand, stress effects on learning appear to be due to an interaction of norepineprine and cortisol. Norepinephrine often influences item memory, and the parietal SME (see project 1) which according to our own work reflects item encoding may reflect norepinephrine activity. In this project we therefore investigate whether stress during learning has distinct effects on item and associative memory and attempt to outline the mechanisms (via ERPs), that explain these changes.
See also:
Halbeisen, G., Buttlar, B., Kamp, S.-M., & Walther, E. (2020). The Timing-dependent Effects of Stress-induced Cortisol Release on Evaluative Conditioning. International Journal of Psychophysiology, 152, 44-52.
Kamp, S.-M., Endemann, R., Domes, G., & Mecklinger, A. (2019). Effects of acute psychosocial stress on the neural correlates of episodic encoding: Item versus associative memory. Neurobiology of Learning and Memory, 157, 128-138.
Research focus Psychobiology of Stress
5. The Von Restorff effect in free recall in young and older adults
Events that deviate from their learning context (for example a type of fruit in a list of animal names) are freely recalled with an enhanced probability. This project investigates the influences on this so-called Von Restorff effect (named after its discoverer) of (1) the type of feature in which these events deviate from their context (for example, semantic or physical features), and (2) the strategies that participants use during episodic encoding. Furthermore, we examine age differences between young and older adults. ERPs recorded during the learning task are used to draw conclusions about the underlying neuro-cognitive mechanisms.
See also:
Kamp, S.-M., Brumback, T., & Donchin, E. (2013). The component structure of ERP subsequent memory effects in the Von Restorff paradigm and the word frequency effect in recall. Psychophysiology, 50(11), 1079-1093.
6. Neuro-cognitive mechanisms of meta-memory in young and older adults
Subproject 1: How do young adults judge their own memory performance?
Our subjective impression of our own memory performance is called meta-memory and is often studied with the "judgments of learning" technique: A rating to estimate one's own later memory performance is given while or after new information is encoded in a learning task. Although there is a lot of research using judgments of learning as a measure of meta-memory, it is to date unclear on the basis of what information participants make these judgments. One idea is that participants rely on conceptual fluency of the to-be-learned information to make their judgments of learning. ERPs (especially the N400 component of the ERP) are used in this project to test this hypothesis. Part of this project is a collaboration with Dr. Monika Undorf (University of Mannheim).
Subproject 2: How does meta-memory change with age?
In this project, which is in part addressed in the AnFAnG-Study, we examine how (and how accurately) older adults judge their own memory capacity.
See also:
Undorf, M., Amaefule, C. O., & Kamp, S.-M. (2020). The neurocognitive basis of metamemory: Using the N400 to study the contribution of fluency to judgments of learning. Neurobiology of Learning and Memory.
7. Neuro-cognitive mechanisms underlying the survival processing effect
Items that are encountered in the context of a survival scenario and that are judged according to their relevance for survival are associated with increased free recall rates, compared to items judged according to their relevance in a control scenario (for example a scenario of moving into a new apartment). The encoding mechanisms that lead to this change in memory performance known as the survival processing effect are still under debate). In this study, ERP SMEs in the encoding phase of a survival processing condition are compared to a condition using a moving scenario to help answer this question. This project is supported by a grant from the German Research Foundation and is a collaboration with Meike Kroneisen (University of Landau) and Edgar Erdfelder (University of Mannheim).
See also:
Kroneisen, M., Kriechbaumer, M., Kamp, S.-M., & Erdfelder, E. (in press). How can I use it? The role of functional fixedness in the survival processing paradigm. Psychonomic Bulletin & Review.
Forester, G., Kroneisen, M., Erdfelder, E., & Kamp, S.-M. (2020). Survival processing modulates the neurocognitive mechanisms of episodic encoding. Cognitive, Affective and Behavioral Neuroscience, 20, 717-729.
Forester, G., Kroneisen, M., Erdfelder, E. & Kamp, S.-M. (2019). On the role of retrieval processes in the survival processing effect: Evidence from ROC and ERP analyses. Neurobiology of Learning and Memory.
8. Projects on the psychophysiological basis of emotion, attention and memory
We regularly conduct basic EEG/ERP studies on the psychophysiological basis of emotion, attention and memory. For example, several of our studies use the so-called "oddball-paradigm", which is a simple but effective paradigm to elicit the P300-component (and related components) of the ERP. The goal of these basic studies is to identify stimulus, task and context variable that affect amplitude and latency of ERP components. Thereby, we are trying to reach a better understanding of the functional significance of ERP components.
See also:
Kamp, S.-M. (2020). Preceding stimulus sequence effects on the oddball-P300 in young and healthy older adults. Psychophysiology, 57(7), e13593.
Kamp, S.-M., & Donchin, E. (2015). ERP and pupil responses to deviance in an oddball paradigm. Psychophysiology, 52(4), 460-471.
Kamp, S.-M., Murphy, A. R., & Donchin, E. (2013). The component structure of event-related potentials in the P300 speller paradigm. IEEE Transactions on Neural Systems and Rehabilitation Engineering, 21(6), 897-907.
Kamp, S.-M., Potts, G. F., & Donchin, E. (2015). On the roles of distinctiveness and semantic expectancies in episodic encoding of emotional words. Psychophysiology, 52(12), 1599-1609.
Potts, G. F., Martin, L. E., Kamp, S.-M., & Donchin, E. (2011). Neural response to action and reward prediction errors: Comparing the error‐related negativity to behavioral errors and the feedback‐related negativity to reward prediction violations. Psychophysiology, 48(2), 218-228.
