Chord skill: learning optimized hand postures and bimanual coordination

Area of Science:

• Motor control
• Cognitive psychology
• Human-computer interaction

Background:

• Skilled motor control is crucial for tasks like typing and playing instruments.
• The exact mechanisms underlying learned finger movements, such as hand postures versus spatial representations, remain debated.

Purpose of the Study:

• To investigate whether skilled finger movements are controlled by learned hand postures.
• To examine the role of practice in developing bimanual coordination and overcoming finger interference.

Main Methods:

• A reaction time study with 32 participants practicing 6 simultaneous key-press responses.
• Participants used either four right-hand fingers or two fingers of both hands.
• Testing involved practiced and novel chords with familiar and unfamiliar hand configurations.

Main Results:

• Participants demonstrated learning of hand postures over spatial or explicit chord representations.
• Bimanual coordination skills were developed through practice with both hands.
• Finger interference slowed chord execution, with practice eliminating it for some chords but not others.

Conclusions:

• Skilled finger movement control is primarily based on learned hand postures.
• Learned hand postures can still be affected by adjacent finger interference even after extensive practice.