Research Focus

Alessandra Angelucci's research focuses on identifying neuronal circuits that underlie functional properties of neurons in the visual cerebral cortex and, ultimately, visual perception. The laboratory uses electrophysiological recording of cortical neurons and co-injecting neuroanatomical tracers to map neuronal response properties onto the underlying anatomical structure. To determine the broader functional organization of specific cortical circuits, optical imaging of neuronal populations is combined with injections of anatomical tracers.

chart of visual response
A. Circuits in the visual cortex that generate the receptive field center and surround of cortical neurons.
B. Neural network model of center-surround responses in visual cortex.

At the early stages of visual processing, the retina and brain deconstruct visual scenes into a series of elementary features and attributes, such as color, orientation of line segments, direction of motion, ocularity and spatial location. These properties are segregated in different cortical areas. Research in the lab is currently directed towards understanding how and where in the visual cortex visual signals arising from distant locations in the visual world are integrated into a coherent percept. Specifically, we are studying neural circuits that might underlie long range interactions across visual space and their role in visual perception. A second major line of research is aimed at identifying neuronal circuits that mediate cross-talk between segregated functional streams specialized in processing visual attributes such as color, form and motion.

photo of brain patches

Patterns of feedback
from higher cortical
areas to visual cortex.

Neurons in visual cortex respond to stimuli in a small region of the visual space called the receptive field center. Visual stimuli outside the center (the surround) do not excite the cell, but can suppress the cell's response to visual stimuli in its RF center. The surround plays an important role in our perceptual ability to distinguish a visual object from background. Understanding the brain circuits that generate center and surround responses is an important step in understanding how the normal brain"sees" and what goes wrong when vision is impaired.