FriSem
Date
Fri June 10th 2022, 3:15 - 4:30pm
Location
Where: Building 420 050 or Zoom (hybrid format). Note the max capacity in room 050 is 36.
Monika Graumann, a Ph.D. student at Freie Universität Berlin
Title: Invariant Object Representations in the Human Brain
Abstract: In order to derive abstract representations of objects, the human brain needs to form object representations that are invariant to low-level sensory information. In this talk I will present two different lines of research in which we investigate the neural mechanisms underlying such representations. In the first part I focus on how category-invariant representations of an object’s location are formed. We performed an fMRI and an EEG experiment in which we superimposed objects on cluttered backgrounds to experimentally approximate real-world viewing conditions. Our results challenge more traditional views on how object location is represented in the brain. We found that category-tolerant location representations emerged ~180 ms later and peaked in object-selective area LOC when objects were superimposed on cluttered, naturalistic scenes. Furthermore, location representations were modulated by top-down visual attention. Our results show that object location is processed in late rather than early processing stages along the ventral stream hierarchy when objects are presented under complex viewing conditions. Together, these findings provide a new perspective on the role of ventral visual cortex in object perception and show how attention impacts the underlying neural processing. In the second part of this talk I will present preliminary results on how invariant Braille letter representations emerge in the brains of congenitally blind individuals.