B05
Our accelerating multimedia-dominated word requires us to cope with an ever-growing flood of visual impressions in an efficient way. This particularly includes parallel-processing of visual information. Parallel processing, however, is limited by the speed and flexibility of attentional resource allocation, which unfortunately decrements with age. This project aims to understand which processes and structural properties of the human cortex underlie efficient parallel processing by employing high-resolution spatiotemporal brain imaging (EEG,MEG, fMRI) and structural imaging methods. We particularly focus on the relationship between the speed of cortical processing and the degree of cortical myelination as a function of age. To assess parallel processing experimentally, we use multiple object tracking (MOT) where participants are to track multiple independently moving objects, as well as multiple feature tracking (MFT) requiring participants to track multiple feature-values of the same object.
Principal Investigators
Prof. Dr. med. Jens-Max Hopf
Prof. Dr. med. Mircea Ariel Schoenfeld
Co-Workers
Dr. Mandy Bartsch
Anna-Maria Felßberg
Dr. Hendrik Griep
Dr. Christian Merkel
Nadine Schönemann
Speed of attentional allocation as a limit of parallel processing
According to our central working hypothesis, subjects cannot attend multiple feature-values of an object (like different colors) at a time. Instead, they are focused one at a time in fast cycles. This cycling of attention through the feature values gives an impression of simultaneous processing. In essence, however, parallel processing would be a serial cycling process, whose limits are set by the speed of the cycle. There is a clear link between neural myelination and the speed and accuracy of neural transmission, hence our goal to clarify the relation between cortical myelination and the efficiency of parallel processing.
Visual attention
We conceive of visual attention as the ability to scrutinize and select details of a visual scene with preference. This has the beneficial effect of better and faster detection, processing, and release of action. It is also possible to scrutinize and select items away from gaze (outside foveal vision), which is referred to a covert visual attention. Attention can be allocated to objects, locations, and features, which is called objects-based, space-based, and feature-based attention, respectively.
Object Tracking
Visual attention plays a huge role in more natural environments of daily life. Hereby, scenes are more dynamic and complex compared to the ‚laboratory’. However, we are still able to navigate in such an environment by being able to attend multiple dynamic pieces of visual information simultaneously. Research shows that up to 4 or 5 visual objects can be captured by attention and that subjects are able to track that information not just through their location within the visual field but many other visual properties.
Object Tracking as a cognitive resource
The ability to track multiple objects over time within our visual environment is an indicator of cognitive health. High functioning cognitive individuals show high scores in object tracking tasks. Research shows that exercising object tracking can increase general visual cognitive performance and maintain cognitive flexibility.
Goals of our Project
This project seeks to clarify the mechanisms and limitations that underlie the flexible cognitive resource allocation in situations where multiple visual input streams need to be simultaneously processed like when navigating highly dynamic visual scenes. We aim at pinpointing the cortical structures and understand the role and speed of cyclic resource allocation of attention as a limit of parallel processing. In addition, we seek to characterize the relation between cortical myelination and the efficiency of parallel processing in MOT and FMT. of These processes will be investigated as a function of age. The potential of the skill of tracking multiple objects/features to retain cognitive flexibility in old age is being examined.