Chapter 8

Question 1

Apraxia results from damage to _______ posterior parietal lobe or its connections, but apraxia results in symptoms _________

Answer 1

Left

On both sides of body

Question 2

What are mirror neurons?

Answer 2

Neurons that fire when an individual performs a particular goal-directed hand movement. They also fires when one observes the same goal-directed hand movement performed by another person

Question 3

What is the motor homunculus?

Answer 3

Somatotropic map of the primary motor cortex

Question 4

What is the stereognosis and how is it facilitated by input from the skin? What term refers to a deficit in stereognosis?

Answer 4

One hand area in primary cortex receives input from skin receptors that facilitates stereognosis, which is the process of identifying objects by touch. An inability to identify objects by touch is referred to as asterognosia

Question 5

It has been estimated that the cerebellum contains __________% of the brains total mass?

Answer 5

10%

Question 6

What symptoms occur with diffuse cerebellar damage?

Answer 6

• inability to control the direction, force, amplitude of movements
• Inability to adapt patterns of motor output to changing conditions
• Difficulty maintaining a steady posture
• Impairment in gait, balance, speech, and eye movement control
• Difficulty learning new motor sequences

Question 7

List and describe the 3 principles of sensorimotor function

Answer 7

• is hierarchically organized-higher levels (association cortex) focus on more complex tasks than lower levels (motor neurons muscles)
• Motor output is guided by sensory input-sensorimotor system monitors external world
• Learning changes the nature and locus of sensorimotor control-as well learned tasks become automatic and require less conscious control, they are taken over by lower levels of the nervous system