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Lichtenberg

Projektlaufzeit: 01.01.2019

Projekt: Lichtenberg

Although huge advancements have been and still are made day-to-day in our understanding of the adult human brain, we know surprisingly little about the brains of children. Healthy brain development, however, is essential for human life: Disturbances of brain development during infancy and childhood, e.g. through accident, disease or disorder, will have a life-long impact on the affected person. It is thus of utmost importance to study and understand the development of children’s brains. The Lichtenberg project focuses on the developmental trajectories of child vision, thus focusing on the question “How do children see the world?”. To answer this question, we utilize both behavioral and neuroimaging experiments in cross-sectional and longitudinal approaches. While high-level visual functions are investigated as well, the Lichtenberg project is mainly dedicated to studying basic and midlevel visual functions. This approach allows us to target important gaps of knowledge that exist in our current understanding of visual development and our results will serve as important stepping stones towards clinical and applied research.

Projektteam (alphabetisch): Limbach, Meissner, Mount, Weigelt

Sub-Projekt: CORTEX

Projektteam: Meissner, Weigelt

While the adult visual cortex is among the most studied parts of the brain and among the best understood, our knowledge of the visual cortex of children and adolescents so far is extremely limited. At the same time, the importance of studying the development of the layout of the visual cortex is illustrated by the fact that this layout is highly adaptable throughout development: astonishing cases of plasticity or re-organization – e.g. the insertion of a complete retinotopic map in one hemisphere (Muckli et al. 2009, PNAS) – have been shown in the developing cortex of young neurological patients. However, mapping the entire visual cortex with its at least 30 functional areas per hemisphere using standard methods—that is, functional localizers—would require at least two hours of brain imaging with magnetic resonance imaging (MRI). But as even small movements during MRI acquisition impair data quality severely (Meissner et al. 2019), this is too long for children. Therefore, we will develop and validate a new “movie localizer” that enables us to map the entire visual cortical network in one participant in approximately 30 minutes. The idea is to unite all the necessary combinations of experimental conditions within a real movie, an approach pioneered ten years ago when object-, scene-, and face-selective areas in human adults were mapped using sections of a western movie (Hasson et al. 2004, Science). For our approach, we will create our own movie to have full control over experimental conditions, maximum efficiency regarding detection power and time, as well as a coherent story line which has the benefits of ensuring high attention and low motion.

Sub-Projekt: V1

Projektteam: Mount, Weigelt

What does it mean to perceive something? Perception is more than the mere sensory recall of images projected onto the retina. Instead, our cortex engages in a constructive process, allowing us to perceive things that may not be present in the actual world such as visual illusions. The early visual cortex (V1) seems to hold a special role in the debate where the transition from sensation (i.e. sensory recall) to perception occurs. While V1 represents the main entrance for visual information into the visual cortex through projections from the thalamus (sensation), the majority of V1 activity is influenced by feedback projections from higher visual areas rather than retinal input (perception; Muckli & Petro, 2013). Thus, V1 is involved in both, sensation and perception, in the adult visual system. It is known however, that e.g. the ability to perceive certain visual illusions has to develop during childhood. Research has shown that children before the age of 7 are insusceptible to the Ebbinghaus illusion and that adult-levels of susceptibility are not reached before age 11 (Doherty et al., 2010). Moreover, the strength of this illusion seems to depend on V1 area size (Schwarzkopf et al., 2011). By studying both the developmental trajectory towards the Ebbinghaus illusion (via behavioral measurements) and of V1 area size (via retinotopic mapping), we aim to deepen our understanding of the development of the visual cortex and the distinction between sensation and perception.

 

Sub-Projekt: Maps & Midlevel

 

Sub-Projekt: Case LS

 


Nebeninhalt

Kontakt

Tobias Meißner, M.Sc.

Betreff: Lichtenberg