We cordially invite you to the Ph.D. Seminar, which will be held on March 22, 2024 at 10.30 in the Konorski room (2^nd floor). There will be 3 presentations:

MSc Marco Ninghetto
MSc Alicja Olszewska
MSc Maciej Gaca

Information regarding speakers together with abstracts can be found below. The seminar will be held in a hybrid mode.

Link to the meeting: https://zoom.us/j/98980745541?pwd=bnFkRjJIcGxsQm1TTHZERWRyOTN4dz09

MSc. Marco Ninghetto
Laboratory of Brain Imaging
Proposed supervisor: Dr. Kalina Burnat PhD., DSc.

Title: Cortical response to transient and long-term loss of visual field

Abstract:

In the cortical representation of the visual field, receptive fields (RFs) form a gradient from small sizes in the center to the largest at the periphery. Using functional MRI mapping of population RFs, we investigated RF readjustments in the dorsal and ventral subdivisions of V1, V2, and V3 in patients after long-term photoreceptor degeneration, in the central (Stargardt, STGD) and peripheral retina (Retinitis Pigmentosa, RP). To model peripheral loss, we transiently limited the visual field to 10 degrees. Transient peripheral loss in controls led to an increase in RF size in V1 and a decrease in V2-3, irrespective of the dorsal-ventral division of the cortical representation of the visual field. Peripheral loss in RP led to a bilateral pRF increase in V1 but a decrease in V2. In contrast, central loss in STGD led to the increase in dorsal visual cortex RF size in the V1-3 areas. Our findings suggest the dorsal-ventral difference in RF size in response to visual field loss, likely reflecting the functional relevance of these divisions within the cortical representations of the visual field. Next, we used a motion-acuity task developed by us, for assessment of visual impairments in fMRI sessions to look for brain areas involved in transient and long-term peripheral loss.

MSc.  Alicja Olszewska
Laboratory of Brain Imaging
Proposed supervisors: Prof. Artur Marchewka, PhD., DSc. and Dr. Aleksandra Herman, PhD., DSc.

Title: Musical Training as a Model for Studying the Dynamics of Neuroplasticity

Abstract:

Musical training has been frequently employed as a tool to study musical-training-related neuroplasticity. However, the dynamic nature of the neuroplastic processes remains less explored.

This project integrated longitudinal and cross-sectional designs to investigate the changes in brain activation of novice pianists. During the study, participants underwent up to seven functional magnetic resonance imaging (fMRI) sessions to track brain activation changes at various time intervals. Novice pianists undertook twenty-six weeks of piano training and participated in in-scanner and behavioural musical tasks, including music listening and playing with varying bimanual coordination demands, or performing a tonal working memory task. In addition, results were compared to performance of passive controls and trained musicians.

The results indicate that brain reorganisation occurs mainly in the motor system and is highly dependent on the task and its demands. The adaptations in auditory processing are subtler on the neural level and have no effects on tonal working memory. Noticeably, the observed time-courses are highly region-, timeframe- and task-specific. Thus, no single model of brain plasticity can fully explain the observed changes. These findings highlight the complexities of neuroplastic processes which underlie learning.

MSc.  Maciej Gaca
Laboratory of Brain Imaging
Proposed supervisor: Prof. Artur Marchewka, PhD., DSc.

Title: Learning to Read Braille: Neuroplasticity and Sensory Integration in the Sighted and Blind

Abstract:

Braille reading leverages cross-modal plasticity, emphasising the brain's ability to reallocate functions across sensory domains. It engages motor and sensory areas, as well as language and cognitive centres. Regions traditionally involved in visual reading, like the visual word form area (VWFA), also activate during Braille reading.

Despite these insights, no study has used a complex reading task to monitor neural activity shifts during the first three months of Braille training to understand cross-modal plasticity.

Using the Lexical Decision Task in an fMRI scanner in sighted learning tactile Braille, we observed that VWFA activation - considered an indicator of cross-modal plasticity - was not detected until six weeks into the course, suggesting that proficiency in tactile reading influences the onset of cross-modal plasticity. However, once this activation was achieved, the peak level of VWFA engagement remained stable, even after a three-month break from Braille learning.

A comparison of blind and sighted Braille readers revealed high activity in both groups in the VWFA, underscoring its modality-independent role.

The findings illustrate cross-modal plasticity, with visual processing areas repurposed for tactile input, enabling linguistic comprehension through tactile modality. This research contributes to our understanding of neuroplasticity, revealing converging adaptations in both the blind and the sighted.