Research


Is sensory processing confined to dedicated brain modules, such as the visual and somatosensory cortices? (FNP “Homing Plus”)
Project Leader: Marcin Szwed, PhD
Jagiellonian University in Krakow

About:

According to the canonical view, the brain processes sensory input in dedicated and distinct systems: the visual system, the somatosensory and so forth. The metamodal view in contrast sees the brain is a flexible task machine, in which each area supports a specific task, computation or representation, irrespective of the sensory modality of the input.

We have recently provided evidence in support of the metamodal view in an fMRI experiment with blind Braille readers. Within the ventral visual areas, a region known as the Visual Word Form Area (VWFA) develops expertise for reading in the sighted. We found that that Braille-reading activation in congenitally blind peaked in the visual areas in the VWFA with astonishing anatomical consistency (Reich, Szwed et al., 2011). The VWFA thus could specialize in reading regardless of sensory modality.

Here I want to carry out a critical test of the metamodal theory. I want find out whether learning Braille causes the VWFA to become metamodal in sighted subjects with a “normal” visual system, even without the large-scale plasticity that goes on in congenitally blind. I plan to compare brain activity and structure before learning Braille and at the end of training, when sighted subjects have become fluent Braille readers. My project combines functional and structural MRI with a long term learning approach in a special subject population and could bring about a fundamental change in our understanding of the brain.

Society for Neuroscience Annual Meeting, Washington, DC, USA

“The visual cortex is not exclusively visual, and plays a critical role in tactile Braille reading. fMRI, resting-state fMRI and TMS evidence from sighted Braille readers”. Bola, Ł., Siuda, K., Paplińska, M., Sumera, E., Jednoróg, K., Marchewka, A., Śliwińska, M., Szwed., M.

 

The study by the Szwed group revealed that the so-called visual word form area (VWFA) in sighted subjects can process tactile Braille reading. (A) Behavioral effects in words read per minute in Braille during the course of training. (B) fMRI results – at the end of the course, Braille reading engaged VWFA (left panel) and other structures involved in visual reading. (C) Results of resting state fMRI – increased functional connectivity was observed between VWFA (red sphere)