Op-brai120289 1..8

نویسندگان

  • Michele Tinazzi
  • Angela Marotta
  • Alfonso Fasano
  • Francesco Bove
  • Anna Rita Bentivoglio
  • Giovanna Squintani
  • Lara Pozzer
  • Mirta Fiorio
چکیده

In focal hand dystonia, the cortical somatosensory representation of the fingers is abnormal, with overlapping receptive fields and reduced interdigit separation. These abnormalities are associated with deficits in sensory perception, as previously demonstrated by applying tactile stimuli to one finger at a time. What is still unknown is whether the sensory deficits can be observed when tactile perception involves more than one finger. To address this issue, we applied ‘Aristotle’s illusion’ to 15 patients with focal hand dystonia, 15 patients with dystonia not affecting the hand (blepharospasm and cervical dystonia) and 15 healthy control subjects. In this illusion, one object touching the contact point of two crossed fingertips is perceived as two objects by a blindfolded subject. The same object placed between two parallel fingertips is correctly perceived as one. The illusory doubling sensation is because of the fact that the contact point between the crossed fingers consists of non-adjacent and functionally unrelated skin regions, which usually send sensory signals to separate spots in the somatosensory cortex. In our study, participants were touched by one sphere between the second–third digits, the second–fourth digits and the fourth–fifth digits of both hands, either in crossed or in parallel position, and had to refer whether they felt one or two stimuli. The percentage of ‘two stimuli’ responses was an index of the illusory doubling. Both healthy control subjects and dystonic patients presented Aristotle’s illusion when the fingers were crossed. However, patients with focal hand dystonia presented a significant reduction of the illusion when the sphere was placed between the crossed fourth and fifth digits of the affected hand. This reduction correlated with the severity of motor disease at the fingers. Similar findings were not observed in non-hand dystonia and control groups. The reduction of Aristotle’s illusion in non-affected fingers and its preservation in affected fingers suggests dissociation between the abnormal processing of sensory signals and the motor impairment. Based on previous evidence showing that the sensory signals coming from the fourth digit determine lower activation in the somatosensory cortex than those coming from the fifth digit, we suggest that in the crossed position, the tactile information conveyed by the fifth digit prevailed over the fourth digit, thus resulting in the perception of one stimulus. The reduction of the illusory doubling perception, therefore, may represent the functional correlate of the different level of activation between the fourth and the fifth digit in the somatosensory cortex.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Small G-protein activation in articular chondrocytes by interleukin-6, interleukin-8, and osteogenic protein-1

The studies outlined in this honor’s thesis were designed to better understand the mechanisms at both the cellular and molecular levels associated with the onset of osteoarthritis. The horse was used as a model organism, and the experiments were performed on normal equine chondrocytes cultured in vitro. Interleukin-6 (IL-6) and interleukin-8 (IL-8) are known to have catabolic effects on the car...

متن کامل

Building Fault Survivable MPI Programs with FT-MPI Using Diskless Checkpointing

"!# $ &% ' (*) + !-,. / 0 "' . + 1 . !" /, 32546 7 + 8' 9: !# + ;9< 9: =' !->? . + @' +!# ,5 !-,. !BA 8' >B(+ C ' ;D !. 5 !+ E "' (6 F !-,. G H "' I . + !, ' >#!8'3 !. JC 6>B . , + &% ' (*) K' L !B M' 6 ' >->B(+ 9 N M . ,. " O !-OP &% =' !-># M2Q!B . M R* ; !# , 9 >C N( N S =' !#>.4. + N F &% '8(*) F !-,. G 0 "' C + 9 !,5' >-!8' !. E 8' T E O&!#O. C &% C =' !-># I' %U4. H .4 2Q OP 5 ; !G' &% 0'...

متن کامل

Lab Assignments

Lab Assignments Instrumentation Labs: Name of Lab Assignment: Lab 1 Introductory Experiments and Linear Circuits I [1] Lab 2 Linear Circuits II [2] Lab 3 Semiconductor Diodes [3] Lab 4 JFET Circuits I [4] Lab 5 JFET Circuits II [5] Lab 6 Op Amps I [6] Lab 7 Op Amps II [7] Lab 8 Op Amps III [8] Lab 9 LabVIEW Programming [9] Lab 10 Analog to Digital and Digital to Analog Conversion [10] Lab 11 Si...

متن کامل

Lab Assignments

Lab Assignments Instrumentation Labs: Name of Lab Assignment: Lab 1 Introductory Experiments and Linear Circuits I [1] Lab 2 Linear Circuits II [2] Lab 3 Semiconductor Diodes [3] Lab 4 JFET Circuits I [4] Lab 5 JFET Circuits II [5] Lab 6 Op Amps I [6] Lab 7 Op Amps II [7] Lab 8 Op Amps III [8] Lab 9 LabVIEW Programming [9] Lab 10 Analog to Digital and Digital to Analog Conversion [10] Lab 11 Si...

متن کامل

Topology of the Octonionic Flag Manifold Augustin-liviu Mare and Matthieu Willems

The octonionic flag manifold Fl(O) is the space of all pairs in OP 2 × OP 2 (where OP 2 denotes the octonionic projective plane) which satisfy a certain “incidence” relation. It comes equipped with the projections π1, π2 : Fl(O) → OP , which are OP 1 bundles, as well as with an action of the group Spin(8). The first two results of this paper give Borel type descriptions of the usual, respective...

متن کامل

Biotech MERCOSUR project: an integrated genotyping and phenotyping platform of Eucalyptus germplasm for mapping purposes

Background The Biotech MERCOSUR project (85% founded by the European Union) launched in January 2009 and finished in December 2010. The general objective was to establish a regional scientific-technological network to develop a genotyping and phenotyping platform useful for the improvement of Eucalyptus in the region. Two advanced genomic strategies (genetic and association mapping) were applie...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2013