Understanding how the brain controls drawing and handwriting

  

A practical activity

Lets explore, in a practical way, how movements are controlled by the brain interacting with the joints and muscles of the arm and hand. 
 
For the activities you will need:
Several sheets of A4 paper
A pen or pencil
A black permanent marker pen
 

Experienced handwriters can write a sentence without needing visual guidance 

On a sheet of paper, write the following sentence first with your eyes open, and then with them closed:  The sun is shining today.
 
Most likely your handwriting is much the same as usual with your eyes closed.  The words are probably well spaced as well. 
 
handwriting sentence with eyes closed.jpg
 
This is because fluent and efficient handwriting is produced with minimal need for visual feedback. 
 
Now produce two lines of handwriting with your eyes closed: Today the sun is shining but we are expecting it to rain tomorrow and the next day. 
 
Handwritng 2 lines with eyes closed.jpg
 
Take a look at what you have written. Most probably each word is quite well formed.
 
Does your writing starts to slope one way or the other? Was it difficult to tell when you have reached the edge of your paper and also where to start the next line?
 
Visual monitoring of handwriting is important for positioning of the handwriting on the page and keeping the writing in a straight line. 
 

Letters are formed by a series of strokes 

Use a black permanent marker and copy the following letters: a, o, h, m. Write them large - about 3 cm high. 
 
Now turn your paper over and take a look at the letters. You will notice that each letter has several small spots. These spots mark the place where the pen has slowed down on the paper between each of the small movements (strokes) that make up the letter.
 
strokes and letters.jpg strokes and letters reverse side.jpg
Letters written with a black permanent marker.  Each letter is formed by a series of small movements called strokes.  The small dark spots on the reverse side of the paper show where the pen hesitated at begining and end of a stroke. 
 
Each stroke is a separate movement with a beginning and an end. The small spots you see on the letters mark the points in the movement where the pen slows down at the end of one stroke and before initiating the next stroke.
Letters are formed by a series of small movements called strokes.
 

The pattern of strokes needed to form a letter are stored in the brain as a motor plan

 
The motor plans (also referred to as representations)  for letters contain information about the the relative length, direction and sequence of the strokes needed to form each letter. 
 
Well learned motor plans control the direction and sequence of the strokes without the need for feedback for completing the movements with reasobable accuracy.    
 

Handwriting movements occur too fast to rely on feedback for controlling each letter 

 
The movements (strokes) used to form letters are pre-planned and very rapid. In fact the speed of fluent handwriting is so fast that there they are completed before any information from the muscles or from vision reaches the brain.  
 
In fluent handwriting each letter is pre-planned and the movement is carried out without the need for visual monitoring or feedback from the muscles. In fact research has shown that after the first few months of handwriting young children not only pre-plan letters, but have started to pre-plan whole syllables. 
 

The equivalance factor: writing big or small uses the same motor plan

 
Take a sheet of paper and turn it sideways. First write you name at the top of the paper in your usual size.  
 
Next sign your name so large that it spans the width of the paper.  To do this you probably kept your fingers still and moved your hand across the paper using shoulder and elbow movements. 
 
Below there is an example of a signature written both small and large.  They look pretty much the same yet  the small signature was written using finger muscles and the large one was written using shoulder / elbow movements. 
 
This is because I have used the same, very well learned motor plan to control the actions, but have increased the size of the letters by sending signals to a different sets of muscles. 
 

Learning to print letters is all about learning the motor plan for the letter

 
Learning to write a letter is a process of learning the relative length, direction and sequence of the strokes that form the letter and storing this information in the brain as a motor plan for the letter. 
 
When a letter is well learned  seeing an example of the letter (grapheme ) or hearing the letter (phoneme) will call up the motor plan for writing the letter.  
 
With repeated the practice the link between seeing, hearing or thinking about a letter becomes more direct, efficient and faster and requires no attention.  
 
When learners have acquired the motor plan for a letter they are able to write the letters without hesitation.  Learners who have not developed a direct link between the letter and the motor plan will hesitate before writing a letter.  
 

Tracing letters inhibits learning the motor plan

Tracing letters or writing a letter guided by an outline of the letter can only be done with any degree of accuracy by using visual monitoring of the movement of the pencil tip. To do this the child uses a series of short strokes to make sure that the line they are drawing stays on the line (or between the lines) on the page.

This has two consequences: children get into the habit  using vision to monitor their actions  and they do not learn the motor plan for the letter.   More about why tracing is a bad idea - and should be banned from handwriting programmes. 

tracing letters.jpg
This is an example of my efforts to trace a letter. Notice how my lines are jagged rather than smooth as I try to keep between the lines.  I do not do a very good job at all.