The vast amount of research in the area of healthy ageing has concentrated on changes at the cognitive stage and their neural correlates. It has been shown that basic cognitive abilities, such as activating, remembering, or retrieving information decline substantially with age. Research related to cognitive and sensory deficits in healthy ageing has a long and established history. By comparison, research on the effects of ageing on perceptual visual functions is still in its infancy. It has been shown that certain perceptual functions change, but to what extent and how those behavioural changes relate to neural functioning is relatively unknown. Recent studies from our lab suggest an age-related specification based on visual experience for different perceptual functions, and it is astonishing how visual experience appears to shape our brains even in adulthood.
In addition to studying behaviour, we are using EEG and fMRI to investigate the long-term effects of visual experience on cortical mechanisms.
Why are we better at discriminating cardinal compared to oblique orientations and motion directions? Using head-mounted displays we eliminate the direct influence of the visual environment on task performance. In addition, we investigate how learning and adaptation affect orientation perception by exposig participants to novel environments.
Using EEG, we investigate neuronal responses to different motion directions and orientations.
Most research on face recognition has been - and still is - based on static images of faces and bodies.This approach is problematic, because in real life, we mostly encounter people in motion. Motion helps us to recognise individuals but also provides important social cues and aids emotion and speech recognition. Studies on emotion recognition from static faces, for example, often have contradictory results favouring angry or happy faces, and basic research on face recognition from static images seems to be subject to large individual differences and often seems to depend on the stimulus being used. Previous research was often limited by the technical advances at the time, but nowadays, we have the ability to use video capture and animation techniques to undertake controlled research on facial and body motion. Therefore, we are using more natural stimuli such as moving faces, point-light walkers and animated body models to assess how and why facial and body motion aids the encoding and later recognition of identity. Studies from our lab show large behavioural advantages for naturally moving stimuli. In addition, we found that brain areas selective for face and body stimuli show increased activation for dynamic stimuli.
Traditionally, it has been assumed that perceptual functions are very similar across neurotypical young adults and individual differences in perceptual experiments have been treated as noise rather than valuable information. This is particularly apparent given the small numbers of highly-trained observers that are often tested in psychophysical experiments. However, more recently, there is a growing awareness regarding the fact that even in perceptual functions, performance differs on an individual basis. We have found large individual differences in groups of older adults, but more importantly, also in untrained younger adults. Observed differences range from those related to basic visual processes including motion and orientation perception to attention.