The Puzzle of Perception
The human eye only resolves a small patch of the visual field in detail - not much more than your thumbnail when you look at it with an outstretched arm. That is why the eyes are constantly in motion. When looking at a photograph or reading this text, rapid jumps of the eye (called saccades) move the center of vision several times per second. The eyes fixate on each point for a brief glance and soon continue their hunt to collect more pieces of the jigsaw puzzle to assemble a seemingly complete picture of the world. But this puzzle is never completed, because selectivity is inseparably built into perception.
My research aims to understand the puzzle of perception a little better. In which ways do attention and memory contribute to conscious experience? How does memory influence what we focus our attention on? How does attention determine how we experience the world and what we learn from it? I am trying to find some answers to to these questions by investigating human performance in visual and memory tasks, analyzing gaze behavior, and studying the neural and behavioral correlates of attention, memory and conscious perception.
The Interplay of Attention and Memory
In one of my favorite projects we investigate the interaction between attention and memory whiles viewing natural scenes in photographs or edited films. Using eye tracking, we investigate how viewers direct their attention when viewing a familiar scene (or a scene that relates to what they have seen before). We realized that attention is very flexible and temporarily adapts to the situation. For example, when it comes to following an edited film or recognizing a familiar photo, attention is quickly and accurately directed to locations that have been viewed before or that are at least very similar to what was seen before. This preference for familiarity seems to be necessary for accurate recognition of pictures and allows to understand how successive shots in an edited film relate to each other. We also try to understand the capacity and stability of this memory and aim to identify its neural correlates in the brain. This could bring us one step closer to understanding how we learn new things from our everyday perceptual experience.
The Individual View of the World
In everyday life, different people usually seem to agree on what they see in front of them - and yet there are sometimes considerable differences between people in how they experience objects in the world. This almost became commonly known when a (somehow low quality) photograph of a dress went viral. Many people disagreed about its color, with everyone being particularly convinced that they were right. Such striking individual differences in perception illustrate that there is no one-to-one relationship between the world's objective characteristics and how it is perceived. Instead, various factors contribute to how sensory signals are ultimately interpreted as subjective perceptual experience. I am particularly interested in understanding why there are stable individual differences in which stimuli capture human attention, and to which degree contextual information determines the outcome of a perceptual moment.
At the Limits of Perception
- Valuch, C., & Mattler, U. (2019). Action priming is linked to visual perception in continuous flash suppression.
Journal of Vision, 19(7), 13. doi:10.1167/19.7.13
- Valuch, C., & Albrecht, T. (2019). Steady-state visually evoked potentials during
continuous flash suppression.
Perception, 48(S), 178.