Instructions to the Participants

 

TITTLE of your presentation together with ABSTRACT one page

and indicating your preference for ORAL or POSTER presentation

  should be submitted via email as Attachment on or before

 

extended deadline June 30 th, 2010

 

MCC ABSTRACT:

 

one page is needed to be submitted in order to be included on WWW of the MCC2010 Conference

Abstracts will be Listed by First Author

 

HOW TO SUBMIT

 GUIDELINES FOR THE SUBMISSION OF ABSTRACTS

 

All abstracts must be submitted by email. This electronic version of the abstract will be used to be included on MCC2010 Conference WWW site. Please carefully read the instructions before writing your abstract. Any abstracts not meeting the given instructions will be returned to the authors for correction.

 

·           The deadline for the submission of abstracts is

extended deadline June 30 th, 2010

 

·           All abstracts need to be submitted in English.

·           The whole abstract must fit in one page.

·           Times New Roman font size 10 should be used.

·           The abstract title should be in UPPERCASE, and fit within two lines, clearly defining the content of the abstract. Please do not use abbreviations in the title.

·           Type the author’s first and family name followed by the co-authors first and family name. Please state the name of the institution or organisation of the presenting author.

·           Leave one blank line after the author(s) and institution / organisation.

·           The body of the abstract should be typed using single line spacing, using the structured subheadings in UPPERCASE as follows: AIMS; METHODS; RESULTS, and CONCLUSIONS.

·           Check the spelling and grammar carefully. Direct reproduction from your electronically submitted abstract text means that any errors in spelling, grammar or scientific data will be reproduced as submitted.

·           Use generic names. Commercial drug names may not be used.

·           Please keep a copy of all submitted materials.

·           Please email your completed Abstract to mcc_conference@yahoo.fr with a copy to nikolai.gantchev@neuf.fr

·           If you have not received confirmation of abstract submission by e-mail within 5 working days of your submission, please contact to check receipt of your abstract.

·           Authors will receive an email indicating the status of their abstract, either accepted for oral or poster presentation by 5 July 2010

·           The presenting author of selected abstracts commits himself/herself to attend the conference and present the abstract in the session at the time decided by the organising committee. A co-author can take over if necessary.

 

  An EXAMPLE

 

 

 

REFLEXIVE CONTROL OF GOAL-DIRECTED ARM MOVEMENT BY THE VISUAL SIGNAL FROM THE TARGET

Sergei Perfiliev, Johan Wessberg.

Institute of Neuroscience and Physiology, Göteborg University, Göteborg, Sweden

 

AIMS

Visually guided arm movement to a target (reaching) is traditionally studied under the assumption that it is voluntary planned and guided by a motor program prepared in advance that describes the movement metrics. Support for this notion was obtained in numerous studies which demonstrated that reaction time (RT) of reaching is substantially prolonged when parameters of movement are unknown in advance. It was established that limb selection and specification of the movement directions are the two most time consuming planning steps, which require at least 300-450 ms. However, in many previous studies responses were made by pressing a button or moving a joystick instead of natural reaching to a target. In contrast, we have recently found that purposeful arm movement can be produced automatically when an unobstructed response toward a moving target is allowed, suggesting reflexive control of the arm by the visual signal from the target. Our aim was to investigate reaching in paradigms in which reflexive properties of arm movement would be clearly revealed.

METHODS

Real objects attached to a string were used as targets. In human experiments a stationary ball in front of the subjects was abruptly shifted 25-40 cm to the left or right, with 1.5-3 m/s peak velocity. The subjects were instructed to concentrate exclusively on the target, keeping both arms equally prepared for action, and to catch the ball as soon as it started to move with any strategy that they felt was the most natural. Positions of passive reflexive markers attached to the ball and to the phalanx of both index fingers were sampled every 2 ms by two optoelectronic tracking cameras (Proreflex, Qualisys, Sweden). Surface EMG was recorded from multiple arm and shoulder muscles. In animal experiments, the target suddenly appeared at a speed of 1 m/s through one of the holes in the sidewalls of a cage and could be accelerated up to 4 m/s. The animals were unaware from which side the target will be presented. The animal’s experiments were recorded by digital video camera.

RESULTS

We found that cats, monkeys, humans and naïve kittens spontaneously use the same automated strategy. Targets moving to the right selectively initiated and directed the right forelimb toward a prospective target position, and vice versa for targets moving to the left. We refer to this strategy as Interception. In humans, the earliest onset of EMG activity ranged in different subjects from 90 to 110 ms, which is less than half than was reported before. Intentional reversal of the Interceptive pattern, i.e. catching the target moving to the left by the right arm and vice versa (we call this Pursuit), prolonged RT on average by 60 ms. The surprisingly short RTs of Interceptive movements indicate that selection of the arm and directing it to the target were automatically induced by parameters of the target motion and was not a result of the subject’s voluntary decision. On the basis of these findings we tentatively suggested hypothesis that arm can be initiated and guided reflexively by the target.

Our hypothesis of reflexive arm control was critically tested in a direct arm-tracking task. Subjects were asked to use their right arm to track directly a ball which was moved continuously in a vertical plane along a curvilinear, irregular path with high and variable speed (0.6-1.2 m/s). All subjects could effortlessly follow the target with very high accuracy (cross-correlation 0.85-0.95) and short and stable time shift of 90-140 ms between the target’s and subject’s velocity trajectories. These results suggest control by hardwired circuits which directly transform with minimal and constant delay the target parameters into corresponding motor output. Thus, responses with the required parameters can be generated automatically without advance elaboration of the motor program and parametric specification of the movement.

In the final task we tested the effect of an irrelevant distracter (20 mm diameter white circle) briefly (100 ms) moving across a monitor on the trajectories of reaching toward a stationary target (40 mm diameter red circle). A switching paradigm, i.e. on-line trajectory correction when in some trials the target is unexpectedly shifted left/rightward, was used as a background task to increase sensitivity of the CNS to moving stimuli. In many trials the distracter induced a small deviation of the trajectory in the direction of the distracter motion. This was not noticed by the participants, and was followed by an immediate correction. The correction was drastically corrupted when we introduced trials where the main target was switched off at the moment the distracter appeared. In these trials the arm consistently and involuntarily followed the distracter, often without any further correction. This strongly suggests that during reaching to a stationary target, the visual signal from the target is critical in keeping the arm trajectory on the right track.

CONCLUSIONS

In summary, the present data indicates that direct and unobstructed reaching toward moving and stationary targets is continuously guided in a reflexive fashion by the visual signal from the target. This suggests that in the previous paradigms that were commonly used to assess motor programming, generation of the movement was delayed due to spatial incompatibility between the target and the response. This resulted in construction of misleading notions of voluntary control and parametric programming of arm movement in space.