Attention is a limited neural resource that enables us to select behaviorally relevant information. We can focus on selected information (exploitation) or search for new, relevant information through a broad attentional filter (exploration). In this project, we investigate the role of the anterior prefrontal cortex in this complex cognitive process.
Prof. Dr. Max Happel
Max Happel is the head of the CortXplorer Research Group at the Leibniz-Institute for Neurobiology in Magdeburg and a professor for physiology at the MSB Medical School Berlin. His research group focusses on in vivo circuit physiology in rodents during learning, memory and decision making.
Prof. Dr. Stefan Pollmann
Stefan Pollmann heads the Experimental Psychology workgroup at the OVGU. His research focuses on the allocation of attentional resources including their neural foundation.
I am a Doctoral student in the Pollmann Lab of experimental Psychology at OvGU. In my work I focus on the brain mechanisms controlling visual attention in humans. In my first years of the Phd I have been investigating the role of the human anterior prefrontal cortex during the unconscious reallocation of attention. In this SFB Project my supervisor and I now work in a collaboration with Max Happel and Parthiban Saravanakumar on the role of the anterior prefrontal cortex in the exploration-exploitation dilemma where we compare behavioral and fMRI data of human participants with gerbils’ behavioral and multichannel recording electrode data.
Parthiban completed a Bachelor’s in Biotechnology at the Rajalakshmi Engineering College of Anna University in Chennai, India. He then came of Magdeburg to study his Master’s degree in Integrative Neuroscience with a thesis on exploratory attentional resource allocation in probabilistic foraging in the Department of Systems Physiology of Learning in Leibniz Institute of Neurobiology, Magdeburg. He is continuing now as a PhD candidate researching prefrontal cortical recruitment of attentional resource allocation during foraging behavior in the same Institute.
What is the anterior prefrontal cortex (aPFC)?
The allocation of attention allows us to focus on the important information for a task at hand. However, in an ever-changing environment, it is necessary to adaptively reallocate the resources of our attention as necessary. The anterior prefrontal cortex (aPFC) is considered a crucial part of a neurocognitive circuit for the neural realization of exploratory resource allocation in human and non-human primates. Exploratory resource allocation is also an essential prerequisite for successful learning processes. Studies suggest that the capacity for exploratory attention declines with age. This may explain an age-related loss of flexibility in behavior.
Exploratory attention in
In humans, we know from imaging studies that the aPFC is activated during exploratory decisions in gambling (Daw et al., 2006) and is a neural correlate of the relative advantage of switching to an alternative action (Boorman et al., 2009). Exploratory behavior can also be influenced by transcranial intervention techniques in the PFC. To approach this phenomenon at the macroscopic level, as well as at the mesoscopic level of neuronal circuits, we designed an experimental paradigm that allows us to study exploitation/exploration trade-offs in humans and Mongolian gerbils.
Although rodents have a less differentiated frontal cortex, they also show exploratory resource allocation. Lesions in the frontal cortex are also associated with various behavioral phenotypes (Olton et al., 1988). To draw conclusions about the neural processing of resource allocation in humans and animals, we examine foraging behavior between depleeting food sources. How long does an individual forage at a food site (exploitation) and when does it decide that it is depleted and it is beneficial moving to a new site (exploration). We have developed a complementary experimental design for human imaging, as well as deriving neural signals from the aPFC in freely moving gerbils.
Investigation of brain mechanisms
of attentional allocation
In human subjects, brain activity is examined in the MRI scanner during the search of objects to be “grazed” by eye movement on a screen. In parallel, in vivo multichannel recordings of neuronal activity across all cortical layers of the frontal PFC are completed in the gerbil during a probabilistic foraging task (Lottem et al., 2018). Thus, we hope to draw conclusions about the macroscopic networks involving different frontal and parietal brain areas, as well as the local neural circuit physiology of the aPFC during attentional allocation.
Project C02 also benefits from the cohort of elderly subjects established within the SFB consortium, as well as the scientific platform for high-resolution human imaging. By comparing cohorts of young and older subjects or experimental animals, we also hope to gain insight into the physiology of age-related decline of attentional resource allocation. Intervention techniques, such as physical exercise, may be able to positively influence these.
A look into the future
By working in parallel with humans and animals, we aim to analyze the basic neural circuits underlying the control of attention. The flexible switches between exploitation and exploration are essential skills for flexible learning and cognitive adaptation processes. In order to better understand which neurotransmitter systems are involved in the control of these processes, further animal experiments are planned. Using optogenetic methods, the role of the dopamine system on the selection of key stimuli in foraging will be investigated by stimulating or inhibiting dopaminergic transmission. How these results can be transferred to humans and which intervention techniques can be derived from this, especially for elderly people, is the subject of further research.
Publications of the project C02
Stefan Pollmann, Werner X. Schneider Handbook of Clinical Neurology (2022)
Laser-Induced Apoptosis of Corticothalamic Neurons in Layer VI of Auditory Cortex Impact on Cortical Frequency Processing
Katja Saldeitis, Marcus Jeschke, Eike Budinger, Frank W Ohl, Max F K Happel Front Neural Circuits (2021)
Lasse Güldener, Antonia Jüllig, David Soto, Stefan Pollmann Front Hum Neurosci (2021)