Chapter 2

Question 1

Four Hypotheses: Sensory Functioning and Cognition

Answer 1

1. Sensory Deprivation Hypothesis: (less social interaction, less vocabulary) less sensory stimulation, less challenge, less cognitive functioning
2. Resource Allocation Hypothesis: during aging tasks become more difficult; reallocation of cognitive resources
3. Common Cause Hypothesis: general decline in sensory and cognitive systems (cause: aging; no direct relation)
4. Sensory impairment influences task performance (e.g. harder to see visual stimuli)

Question 2

How does aging affect food intake? In what what way can physical exercise influence food intake?

Answer 2

1. Sensory system deterioration, including taste / smell, leading to less appetite and thus less food intake.
2. Testosterone levels go down, leading to higher Leptin levels, lowering hunger / appetite, leading to less food intake.

Leptin is produced by adipose tissue, thus reduction in leptin by endurance exercise.

Question 3

What is the result of age-related weakening in the quadriceps?

Answer 3

Joint-position sense muscle receptors cannot work optimally, disturbing JPS in partial-weight condition. This can negatively influence:
(1) Postural Stability, (2) Gait and (3) ADL.

Question 4

What is the difference between dynamic- and static joint-position sense? What is their function (or what is the result of disturbance in theses senses?)

Answer 4

Static: joint position while standing / not moving.
–> influences posture
Dynamic: joint position in motion.
–> maintain balance and proper gait; facilitated by muscle spindles

Question 5

Which subtypes of gait disorders are described in Ch. 2? Which brain areas are involved in these subtypes?

Answer 5

1. lower: peripheral nervous system
2. middle: basal ganglia and cerebellum
3. higher: cortic-cortical pathways and cortico-subcortical pathways.