Peelen began by introducing visual cognitive neuroscience, the study of how the brain enables us to see and understand the world. He highlighted the critical role vision plays in our daily lives, not only for practical tasks like recognizing objects and navigating spaces but also for interpreting emotions, appreciating art, and engaging with others.
The interplay between perception and cognition
One key theme of the lecture was the close relationship between visual perception and thought processes. Peelen explained that the visual cortex is not just a passive receiver of sensory input but an active participant in constructing our mental representation of the world. For instance, when we see an image, our prior experiences, current goals, and expectations influence how we perceive it.
Peelen illustrated this with compelling examples, such as optical illusions and experiments showing how brain activity changes depending on what we are looking for. Peelen also presented how blind individuals perceive the world. He shared results from studies showing that even in people born blind, the so-called "visual" cortex is activated by non-visual information, such as sounds or touch. This suggests that these brain regions are part of broader networks supporting functions like navigation and social understanding.
Peelen referenced the moving experiences of John Hull, a blind professor who documented his transition to blindness. Hull’s reflections offer a window into the role of vision in constructing our understanding of the world and highlight how the brain compensates when sight is lost. Hull’s vivid descriptions of rain bringing out the contours of his surroundings illustrated how sound and touch can replace visual cues to create a rich mental representation of the world.
Implications for Neuroscience
Peelen concluded by emphasizing the importance of studying vision not in isolation but as part of a dynamic system interconnected with cognition and behavior. Modern techniques like functional MRI and artificial intelligence allow researchers to investigate these interactions in unprecedented detail, providing insights into not only how we see but also how we think.
This lecture shows fundamental processes that shape human experience. Watch the full presentation in the embedded video to explore the fuzzy boundary between seeing and thinking yourself: