Sensory Contributions to Skilled Performance

1
Sensory Contributions to Skilled Performance

• Chapter 3

2
Objectives

• Explain the contributions and limitations of a
  closed-loop model of movement control
• Understand the various ways that sensory
  information is used in movement control
• Discuss the various roles of vision in movement
  control
• Understand how sensory contributions to movements
  are part of a conceptual model of motor
  performance

3
Preview

• How is a rugby player able to watch the ball
  leave a teammates hand with a few tenths of a
  second of viewing time and realize she must turn
  her back on the ball and cut sharply in one
  direction to catch it?
• She predicts the balls flight correctly,
  visually focuses on it, times the balls arrival
  into her hands, and compensates for other
  external factors by grasping the ball with two
  hands.

(continued)
4
Preview (continued)

• How is so much accomplished in such a short time?
  
• How are corrections made during skilled
  performance?

5
Overview

• Processing vast amounts of information quickly
  and accurately and making effective adjustments
  as needed
• Processes that allow performers to detect
  patterns of information in the environment and
  use the information to predict future actions
• The neuromuscular system, the conceptual model of
  motor performance, and principles of visual
  control as they relate to movement

6
Exteroception

• From the environment
• Outside of the body
• Highly visual

7
Proprioception

• Information that comes from within the body,
  largely from the muscles and joints

8
Interoception From Inside the Body

• KinesthesisSensory information coming from the
  motor system that signals contractions and limb
  movements
• Vestibular apparatuslocated in inner ear
  information about balance, posture, and
  orientation
• Muscle spindlelocated in skeletal muscle sends
  information about muscle length to CNS

(continued)
9
Interoception From Inside the Body (continued)

• Golgi tendon organslocated between muscle and
  tendon provide information about force in the
  muscles
• Cutaneous receptorslocated in the skin detect
  pressure, temperature, and contact

10
Closed-Loop Control System

• Involves the use of feedback and error detection
  and correction processes to maintain the desired
  goal
• Used to control slow and deliberate movements

(continued)
11
Closed-Loop Control System (continued)

• Good for detecting slow movement
• Not good for explaining rapid movement
• Does not account for discrete tasks

(continued)
12
Closed-Loop Control System (continued)

• Comparatorerror detection
• Executivebrain determines actions to take to
  reach goal
• Effectorcarries out decisions
• Feedbackprovides information on current state

13
Open-Loop Control

• Response selection and response programming
  require considerable time and attention.
• In the closed-loop conceptual model, corrections
  occur a few hundred milliseconds after an error
  occurs.
• The error signal is processed in the
  stimulus-identification stage.

(continued)
14
Open-Loop Control (continued)

• A movement correction is chosen in the
  response-selection stage.
• Modifications to the movement are organized and
  initiated in the response-programming stage.

15
Compensations for Muscle Movements

• M1monosynaptic
• Most rapid, unconscious, one synapse, little
  environmental impact, inflexible
• M2polysynaptic
• Longer muscle, adjusts more than M1,
  higher-level function, knee-jerk, sensory, cant
  modify once begun

(continued)
16
Compensations for Muscle Movements (continued)

• Triggered reaction
• Wineglass effect, learned, conscious, cutaneous
  receptors
• M3voluntary reaction time
• Voluntary affected by instruction,
  anticipation, and stimulus responses supported
  by Hicks law

17
Visual Systems

• FocalIdentifies objects in center of visual
  field is conscious and affected by light
• AmbientDetects orientation of body in
  environment is nonconscious and peripheral

18
Optical Flow

• Detects movement of patterns of light from the
  environment
• Perceives motion, positions, timing, stability,
  velocity, and direction

19
Vision

• How does vision affect balance?
• Visual dominancevisual information dominates
  information coming from the other senses
• Visual capturevisual information attracts a
  persons attention more easily than other forms
  of information