5.2 Brain functioning 2

Question 1

What are the different lobes of the brain ?

Answer 1

• frontal lobe
• parietal lobe
• temporal lobe
• occipital lobe
• limbic lobe

Question 2

What can be said about the frontal lobe ?

Answer 2

• Conscious thought
• Damage can result in mood changes, social differences, etc…
• the frontal lobes are the most uniquely human of all the brain structures

Question 3

What can be said about the parietal lobe ?

Answer 3

• Plays important roles in integrating sensory information from various senses and in the manipulation of objects
• portions of the parietal lobe are involved with visuo-spatial processing

Question 4

What can be said about the temporal lobe ?

Answer 4

• senses of smell and sound

- as well as processing ox complex stimuli like faces and scenes

Question 5

What can be said about the occipital lobe ?

Answer 5

• sense of sight

- lesions can produce hallucinations

Question 6

What can be said about the limbic lobe ?

Answer 6

emotion and memory

Question 7

What are gyri and sulci ?

Answer 7

• A gyrus is a ridge on the cerebral cortex

- It is generally surrounded by one or more sulci (depressions or furrows)

Question 8

Where is the precentral gyrus ?

Answer 8

• in the frontal lobe

- parallel to and anterior to the central sulcus and extends to the precentral sulcus

Question 9

What is and where is located the primary motor complex ?

Answer 9

• It is made of most of the precentral gyrus
• It is involved in the initiation of willed voluntary movement
• contains many of the cells of origin of the descending motor pathways

Question 10

Where is the postcentral gyrus ?

Answer 10

• In the parietal lobe

- Posterior to the central sulcus and lies parallel to it extending posteriorly to the postcentral sulcus

Question 11

What is and where is located the primary somatosensory cortex ?

Answer 11

• It corresponds to the postcentral gyrus

- It is involved in the initial processing at the cortical level of tactile and proprioceptive information

Question 12

In the homonculus drawing, what’s the meaning of the size of the different body parts ?

Answer 12

The bigger the body part, the more brainpower is dedicated to controlling it.

Question 13

Which side of the brain controls which side of the body ?

Answer 13

The right side of the brain controls the left side of the body and vice-versa.

Question 14

What is the amygdala ?

Answer 14

• almond-shaped groups of nuclei located deep within the temporal lobes
• there are two of them, symmetrically arranged near the center of the brain
• considered to be part of the limbic system

Question 15

To which emotions and functions is the amygdala linked ?

Answer 15

• to fear and anxiety - its size is positively correlated to the level of aggression in a given species
• associated with pleasure (in a negative sense)
• not purely associated with any one emotion
• necessary to experience emotions but also to recognize their presence in others
• plays primary roles in the formation and storage of memories associated with emotional events
• not itself a long-term memory storage site, but regulates memory consolidation in other brain regions

Question 16

Which part of the amygdala are involved in the genesis of many fear responses and what are those responses ?

Answer 16

• The central nuclei

- Fear responses : freezing, tachycardia, increased respiration, stress-hormone release

Question 17

Which dysfunctions has poor amygdalic function been associated with ?

Answer 17

• anxiety, autism, social bindness, depression, narcolepsy, PTSD, phobias, schizophrenia
• in monkeys, lesions before 6 months of age result in difficulty adapting to social life