Current evidence suggests that the occipital cortex (normally associated with visual perception) actively participates in non-visual sensory tasks. For example, it has been demonstrated both in sighted and blind individuals that this area is implicated in the processing of sensory information obtained through touch. The purpose of this research proposal is to investigate the neurophysiology and neuroplasticity of cross-modal sensory interactions. Specifically, the study has three aims:
(Aim 1). In congenitally blind and sighted individuals, what roles do occipital (visual) cortical areas play in tactile spatial discrimination tasks? (Aim 2) Does the tactile exploration of complex objects and visual scenes (e.g., faces and houses) by sighted and blind individuals activate known higher-order visual areas? (Aim 3) Does tactile stimulation modulate occipital cortex function? We will employ fMRI and TMS to pursue these questions. Subjects will perform spatial discrimination and object recognition tasks to tactile presented stimuli (simple raised dot texture patterns and complex objects such as faces), fMRI will be used to map and compare the cortical areas activated during these tactile tasks in the sighted and blind. In a second set of experiments, we will assess the modulation of occipital cortex activity and function during a cross-modal visuo-tactile task. TMS will be used to induce and assess changes in phosphene perception as a function of simultaneous tactile stimulation. The candidate wishes to learn, master and combine the techniques of fMRI and TMS with the goal of becoming an independent clinician-scientist. The proposed experiments will contribute to our understanding as to how objects are represented within the visual brain and how information obtained from touch contributes to this processing. Furthermore, comparing these processes in the blind will help uncover the adaptive mechanisms underlying object representation in the absence of vision. These results are likely to have implications for both the rehabilitation and education of the blind and visually impaired. ? ?

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Mentored Patient-Oriented Research Career Development Award (K23)
Project #
5K23EY016131-02
Application #
7104935
Study Section
Special Emphasis Panel (ZEY1-VSN (06))
Program Officer
Oberdorfer, Michael
Project Start
2005-08-01
Project End
2010-07-31
Budget Start
2006-08-01
Budget End
2007-07-31
Support Year
2
Fiscal Year
2006
Total Cost
$150,311
Indirect Cost
Name
Beth Israel Deaconess Medical Center
Department
Type
DUNS #
071723621
City
Boston
State
MA
Country
United States
Zip Code
02215
Plow, Ela B; Obretenova, Souzana N; Jackson, Mary Lou et al. (2012) Temporal profile of functional visual rehabilitative outcomes modulated by transcranial direct current stimulation. Neuromodulation 15:367-73
Plow, Ela B; Obretenova, Souzana N; Fregni, Felipe et al. (2012) Comparison of visual field training for hemianopia with active versus sham transcranial direct cortical stimulation. Neurorehabil Neural Repair 26:616-26
Merabet, Lotfi B (2011) Building the bionic eye: an emerging reality and opportunity. Prog Brain Res 192:3-15
Plow, Ela B; Obretenova, Souzana N; Halko, Mark A et al. (2011) Combining visual rehabilitative training and noninvasive brain stimulation to enhance visual function in patients with hemianopia: a comparative case study. PM R 3:825-35
Halko, M A; Datta, A; Plow, E B et al. (2011) Neuroplastic changes following rehabilitative training correlate with regional electrical field induced with tDCS. Neuroimage 57:885-91
Merabet, Lotfi B; Pascual-Leone, Alvaro (2010) Neural reorganization following sensory loss: the opportunity of change. Nat Rev Neurosci 11:44-52
Bolognini, Nadia; Senna, Irene; Maravita, Angelo et al. (2010) Auditory enhancement of visual phosphene perception: the effect of temporal and spatial factors and of stimulus intensity. Neurosci Lett 477:109-14
Merabet, Lotfi B; Battelli, Lorella; Obretenova, Souzana et al. (2009) Functional recruitment of visual cortex for sound encoded object identification in the blind. Neuroreport 20:132-8
Amedi, Amir; Merabet, Lotfi B; Camprodon, Joan et al. (2008) Neural and behavioral correlates of drawing in an early blind painter: a case study. Brain Res 1242:252-62
Pitskel, Naomi B; Merabet, Lotfi B; Ramos-Estebanez, Ciro et al. (2007) Time-dependent changes in cortical excitability after prolonged visual deprivation. Neuroreport 18:1703-7

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