KNES 305 - CH 2

• Understanding Movement Control involves looking at factors associated with movement preparation
• Identify attention theories, and understand how arousal levels affect performance
• Understand sensory contributions to movement and balance
• Differentiate between short-term, long-term, and working memory

Motor Control and the CNS

• The CNS (brain and spinal column) is the command center, integrating incoming sensory information, processing, and outgoing messages
• The brain weighs 3 lbs. & consists of 100 billion cells and Quadrillion synapses
• Einstein's brain was smaller than average and consumes 20-25% of our energy expenditure
• Adult brains can grow new neurons

Brain

• The Neocortex (Neo = “new”, Cortex = “outer shell") is the controller of the controllers and has 4 lobes: Frontal, Parietal, Temporal, and Occipital
• The Frontal lobe has several divisions that perform different motor functions like activating muscles, planning, and coordination
• The Parietal lobe receives sensory information from the skin and tongue and processes sensory information from eyes and ears
• The Occipital lobe processes information from retinas, color, depth perception, and motion
• The Temporal lobe combines visual and auditory information
• The Thalamus (command center) located below the cortex relays all sensory information

Cerebellum

• The Cerebellum ("little brain") is an important facet of motor activity
• The cerebellum enables higher-level motor coordination and allows learning via practice
• The areas of the cerebellum includes:
• Vestibulocerebellum which is responsible for error correction, balance involving vestibular and visual feedback
• Spinocerebellum which supports locomotion and coordinated trunk activity
• Neocerebellum which interacts with the prefrontal area and cortical areas

Movement Preparation

• Considers sensory information by providing stimuli and information to prepare
• Reaction time, attention and arousal are also considerations

Speed

• Reaction time (RT) measures the time between stimulus presentation and motor response initiation and indicates the speed of decision-making
• Movement time measures time from movement initiation to completion
• Response time encompasses Reaction time + Movement time

Stimulus-Response Alternatives

• Simple reaction time involves one decision, like at a stop sign
• Choice reaction time involves multiple decisions, like at a traffic light (Yellow, Red, Green, Green arrow, flashing yellow arrow)
• Hick's law (Hick-Hyman Law) states the more decisions one must make, the slower the decision time

Psychological Refractory Period (PRP)

• Reaction time is delayed when two stimuli requiring different responses are quickly presented consecutively
• The response to the first stimulus delays the ability to process a response to the second stimulus

Ruler Test

• Involves the use of one ruler for simple reaction time and two rulers for choice reaction time
• Simple reaction time involves temporal anticipation
• Choice reaction time involves temporal and event anticipation

Attention Concepts

• Capacity indicates attentional capacity is not limitless
• Selectivity states that attention is selected either intentionally or incidentally
• Focus indicates attention can be wide or narrow and internal or external

Theories of Attentional Capacity

• Single-channel filter theories states tasks are accomplished serially and the system can only process one task at a time
• Multiple-resource theories notes several attention mechanisms, each with limited capacity
• Tasks requiring a common mechanism will be difficult to perform simultaneously

Attentional Capacity

• Attentional capacity is critical for understanding automaticity of performance
• As skills become automatized, one can attend to other environmental aspects

Focus of Attention

• Direction indicates the focus location can be internal, within the individual, or external, in the environment
• Width indicates the amount of information attended to by the individual such as narrow when attending to one or two cues, or broad when attending to the entire visual field

Attentional Styles

• There are four attentional styles: internal broad, internal narrow, external broad, and external narrow

Arousal vs. Anxiety

• Arousal encompasses a general physiological and psychological activation, varying on a continuum from deep sleep to intense excitement
• Anxiety is a negative emotional state with feelings of nervousness, worry, and apprehension, usually associated with activation/arousal of the body to too high a level

Anxiety

• State anxiety indicates the anxiety level at a single point in time within a specific event or context and is relatively common
• Trait anxiety indicates a predisposition for anxiety in threatening situations and the general level of anxiety in someone's personality
• A calm individual may have increased anxiety in certain circumstances

Inverted-U Hypothesis

• Performance increases with arousal up to a point, then drops off once arousal surpasses the optimal level
• Too little arousal causes underperformance

Sensory Contributions

• Exteroception provides information about the external factors such as vision and audition
• Proprioception provides information about the state of the body, including the sense of movement and the relationship of body parts
• Vestibular apparatus, Joint receptors, Cutaneous receptors, Muscle spindles and Golgi tendon organs

Memory

• Memory encompasses the ability to recall things and learn from experience
• Sensory memory: Under 4 seconds; Includes iconic(vision), echoic(hearing), haptic(touch)
• Short-term memory: Stores information for only 20-30 seconds unless rehearsed
• Working memory: Temporarily stores recently presented material and retrieves long-term information for problem-solving, decision-making, and movement production
• Long-term memory: Involves semantic, procedural, and episodic memories and is relatively permanent