Lily practicing pouring water from a beaker into a bowl
Even a seemingly simple act such as picking up a beaker of water and pouring the water into another container requires high levels of integration of information from many different sources: the body sensors, the environment, past experience with similar actions for planning and carrying out the task.
Past experience is important for planning the action
Information needed for planning the action
Doing the action: reach, grasp, lift, move, pour
After completion of the task - using feedback to adapt the motor plan
Meg and I practice pouring a mug of milk
Meg, aged 7, would like to be able to pour herself a drink of milk without spilling on the kitchen counter in the process. Meg badly needs to build her confidence in her own abilities, especially as she is very aware that her younger brother often succeeds where she fails.
I have persuaded Meg that she can succeed at the task; it just needs a bit of the “right sort of practice”. Meg understands about the right sort of practice: it means persisting, learning from mistakes, not getting discouraged easily, keeping the goal in mind, paying attention to the right things and succeeding.
We start by practicing pouring from a bottle quarter filled with water into a large diameter mug.
I demonstrate the action. I pour a little water into the mug without spilling.
Then I try again, tip the bottle too far, do not keep the lip of the bottle over the mug and pour water onto the table. Oh dear, I made a mistake.
Next it is Meg’s turn. She is careful and pours all the water into the mug without spilling any. We half fill the bottle with water and Meg pours a little water into each of a row of mugs on the table.
I provide feedback: Those were very good tries. You watched me and followed my instructions very well.
We make the task more difficult
Our next step is to fill the bottle with water. This makes it heavy and more difficult to pour without spilling.
Meg pours some water from the full bottle, but moves too slowly and the water gushes out and spills on the table. Oops, that was a mistake. Let’s wipe the table and try again.
I demonstrate the action, moving quite fast and keeping the lip of the bottle over the beaker. Meg watches me intently, nods her head, picks up the bottle, speeds up her movement at the beginning to prevent spilling and pours herself a half a cup of milk.
She looks at me and grins. Success! She says: I am getting good at this.
Meg has learned how to carefully position the lip of the bottle above the mug, how to grade the amount the bottle needs to be tipped to get a steady flow of water into the mug, and also when tip the bottle up again to stop the flow of water.