הרצאת המכון ללימודים מתקדמים

The Institute of Advanced Studies
Lowy Distinguished Guest Professors

Professor Joshua Trachtenberg
David Geffen School of Medicine
University of California, Los Angeles
California, USA

Seminar

"HOW EARLY EXPERIENCES SHAPE CORTICAL CIRCUITRY"

Abstract:
The six-layered neocortex evolved from a three-layered dorsal pallium, around 225 million years ago, during the late Triassic as mammals evolved from therapsids following the Permian-Triassic extinction event. This initiated a shift in sensory and motor processing. Using the visual system as an example, early vertebrates like fish, amphibians, and reptiles process a significant amount of visual information — informing orientation and escape — directly in the retina and the tectum.

This processing remains low-level given the proximity of these structures to the sensory epithelium. As the neocortex emerged, it supported learning higher-order representations defined by combinations of multiple visual features, also referred to as feature conjunctions. These feature conjunctions supported the emergence of visual affordances, which are the potential actions an animal can take based on what they see. In other words, the features of an object determine its uses, and the features of the local scene determine possible actions. These new cortical feature representations are learned in early postnatal life. How complex feature conjunctions are learned has remained elusive.

Using longitudinal in vivo imaging of visually evoked cortical responses to track the emergence of complex binocular visual responses after eye opening, we reveal that the establishment of these higher-order feature detectors is a remarkably dynamic process involving the gain and elimination of neurons from functional groups (e.g. binocular neurons with non-linear response tuning). Experience exerts its influence selectively on this developing circuitry; some pathways require experience for normal development while others appear to be intrinsically established. This difference drives the network dynamism that is exploited to construct novel cortical representations that best encode our local environment and inform our actions in it.

The seminar will be held on Sunday
27 April 2025, at 11:00
Room 01, Webb School of Languages Building 
Tel Aviv University, Ramat-Aviv

Light refreshments will be served before the seminar

The Institute of Advanced Studies
https://ias.tau.ac.il/
 

המכון ללימודים מתקדמים
פרופסורים אורחים מיוחדים ע"ש לאוי

פרופסור יהושע טרכטנברג
בית הספר לרפואה ע"ש דוד גפן
אוניברסיטת קליפורניה, לוס אנג'לס
קליפורניה, ארה"ב
 

סמינר

הסמינר יתקיים ביום ראשון
27 באפריל 2025, בשעה 11:00
חדר 01, בניין ווב בית הספר לשפות 
אוניברסיטת תל-אביב, רמת-אביב

כיבוד קל יוגש לפני הסמינר

https://ias.tau.ac.il/