SINGLE HUMAN NEURONS · Invariant neurons for visual representation in the human medial temporal lobe: A generalized version of rodent place cells?

Lines connect the coordinator with its partners. CORDIS does not always give exact coordinates for projects before 2014. These points are placed at city or country level.

Project objective

One of the most fascinating findings at the level of single neurons are place cells that encode the spatial position of the rodent relative to external environmental cues by means of the cell's firing rate.In the 1990s, Fried and collaborators at UCLA Medical School developed techniques to chronically record single unit activity in awake patients undergoing pre-surgical epilepsy diagnostics prior to respective surgery. Such recordings have provided evidence for a homologue of rodent place cells in humans per forming a navigational task.In another study, cells were found in the human medial temporal lobe that responded specifically and invariantly to different pictures of the same famous person. The sparseness, degree of invariance and temporal dynamics of the firing behaviour of these cells is reminiscent of rodent place cells.The aim of the proposed project is to test the hypothesis that such invariant neurons represent a generalized, cognitive version of rodent place cells responding explicitly to the concet of an object or individual rather than to certain of its features. These neurons may be part of an attractor network.After identifying targets, e.g. a famous person that evokes a specific and invariant response in a neuron, using a novel spike sorting algorithm we will show patients short movies in which the face of one individual the cells does not respond to is gradually morphed into the face of an individual to which the cell responds to (and vice versa). In this way we want to create a situation that corresponds to that of a place cell in a rat upon approaching a place field.Using wavelet-based time frequency analysis, we will assess underlying coding mechanisms in terms of firing rate, relation to the phase of local theta activity and oscillatory interaction with particular respect to theta-gamma modulation.We intend to compare our results to related findings from the very active rodent literature and against different attractor neural network models.

Original text from CORDIS.

Participants

• FACULTY OF MEDICINE, UNIVERSITY OF BONN · BONNCoordinatorCity levelGermany
• CALIFORNIA INSTITUTE OF TECHNOLOGY · PASADENACity levelUnited States

Links

• View on CORDIS