Quantitative Life Sciences SEMINAR

[Quantitative Life Sciences]

_QUANTITATIVE LIFE SCIENCES SEMINAR_

THURSDAY, 23 APRIL 2015, 11:00 a.m.
OPPENHEIMER MEETING ROOM - ICTP Leonardo Bldg., second floor

Davide ZOCCOLAN
(Visual Neuroscience Lab, SISSA Trieste)

*"High-level vision in rats: invariant object recognition and its 
neuronal substrates"**
*
_Abstract_

The ability to recognize objects despite tremendous variation in their 
appearance (e.g., because of position or size changes) represents such a 
formidable computational feat that it is widely assumed to be unique to 
primates. Such an assumption has restricted the investigation of its 
neuronal underpinnings to primate studies, which allow only a limited 
range of experimental approaches. In recent years, the increasingly 
powerful array of optical and molecular tools that has become available 
in rodents has spurred a renewed interest for rodent models of visual 
functions. However, evidence of primate-like visual object processing in 
rodents is still very limited and controversial.

In this seminar, I will present behavioral evidence showing that rats 
are capable of recognizing visual objects in spite of substantial 
variation in their appearance, i.e., in spite of changes in size, 
position, illumination, in-depth rotation and in-plane rotation. I will 
also show that such a transformation-tolerant (or invariant) recognition 
is largely accounted by rat ability to spontaneously perceive different 
views/appearances of an object as similar (i.e., as instances of the 
same object). Next, I will show that rat object recognition relies on a 
shape-based, multi-featural processing strategy that makes 
close-to-optimal use of the discriminatory information afforded by the 
target objects across their various appearances. Finally, I will present 
some preliminary neuronal recordings from rat visual cortical areas that 
run laterally into rat temporal lobe, showing that the deepest (i.e., 
higher-order) area conveys more information about object identity (also 
in spite of variation in object appearance), when compared to 
lower-order (i.e., more occipital) areas (including V1).

Taken together, these findings suggest that the rat visual system may 
serve as a powerful model to study the neuronal substrates of invariant 
visual object recognition.

-- 
Erica Sarnataro
Group Secretary
Quantitative Life Sciences
The Abdus Salam International Centre for Theoretical Physics (ICTP)
Trieste,  Italy
Tel. +39-040-2240623
e-mail: qls at ictp.it