Topic 12- Premotor Cortex

Question 1

Three Basic Function of Premotor Cortex

Answer 1

1) Movement Preparation
2) Establishing a connection between a sensory stimulus and a corresponding motor action
3) Control of Proximal Musculature:​ Directly connected to proximal muscles, particularly those around the hips, for actions like moving the leg

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Question 2

What is the premotor cortex?

Answer 2

A set of interconnected areas in the frontal lobe, positioned rostral to the primary motor cortex (M1).

Question 3

How is the premotor cortex divided?

Answer 3

The premotor cortex is divided into “lateral” and “medial” regions.

Question 4

Where is the premotor cortex located in relation to the primary motor cortex?

Answer 4

The premotor cortex is positioned in front (anterior) of the primary motor cortex.

Question 5

Describe the spatial relationship between the premotor cortex and the primary motor cortex.

Answer 5

The frontal regions of the premotor cortex are rostral (toward the front) relative to the primary motor cortex (M1).

Question 6

What are the connectivity patterns of premotor areas?

Answer 6

Premotor areas have extensive connections with the primary motor cortex (M1) and direct projections to the spinal cord.

Question 7

How do premotor areas select movements?

Answer 7

Premotor areas use information from other regions to select movements appropriate to the context of a required action.

Question 8

What is the primary function of premotor areas?

Answer 8

Premotor areas are primarily concerned with planning movements.

Question 9

When are premotor areas active?

Answer 9

Premotor areas are active during the preparation of movement

Question 10

Medial premotor area​

Answer 10

1) Supplementary motor area (SMA)​
2) preSMA​
3) Cingulate motor area (CMA)

Question 11

Where is the SMA (Supplementary Motor Area) located?

Answer 11

Situated on the medial side, anterior to the precentral gyrus, in front of the central sulcus, depicted in light purple, and adjacent to the pre-supplementary area.

Question 12

Describe the location of the Cingulate Motor Area.

Answer 12

Located caudally, inferior to the supplementary and pre-supplementary motor areas, positioned below the supplementary motor area near the cingulate sulcus.

Question 13

What role does stimulation of medial premotor areas play in movements?

Answer 13

Stimulation of medial premotor areas, induces bilateral movements and is essential for coordinating movements on both sides of the body.

Question 14

What is the SMA’s role?

Answer 14

Crucial for orchestrating complex, sequential motor tasks and is specifically involved in learned sequences of movements

Question 15

Observations in Healthy Individuals: SMA

Answer 15

In healthy people, if you ask them to do a sequence of movements one after another, they get faster with each movement.
Why: Their brains are good at preparing for what’s coming up, making subsequent movements quicker.

Question 16

Patients with SMA Lesions

Answer 16

Main Point: People with spinal muscular atrophy (SMA) lesions have trouble adjusting their movements, no matter how many they have to do in a sequence.

Question 17

What is the clinical correlation between Basal Ganglia damage and the ability to perform sequences of movements?

Answer 17

Patients with Basal Ganglia damage often struggle with executing sequential movements, as seen in conditions like Parkinson’s disease.

Question 18

How are the premotor areas, including the Supplementary Motor Area (SMA), interconnected with the Basal Ganglia?

Answer 18

Premotor areas, including the SMA, receive substantial input from the basal ganglia, forming highly interconnected circuits that play a crucial role in motor planning.

Question 19

How does the interconnected network between SMA and Basal Ganglia contribute to motor planning and coordination?

Answer 19

The interconnected network between SMA and Basal Ganglia is crucial for planning and coordinating our movements. They work together to organize and update the details needed for smooth and effective execution of sequential actions, making them essential partners in motor planning and coordination.

Question 20

What was a notable discovery about SMA neuronal response based in monkeys were trained to perform specific sequences, such as pushing, pulling, or turning a handle.

Answer 20

Certain cells in the SMA are tuned to specific actions, and their activity is affected by the context or pattern in which these actions are performed.

Question 22

What is the specific role of the Pre-Supplementary Motor Area (Pre-SMA) in motor sequences?

Answer 22

Pre-SMA focuses on learning new motor sequences.

Question 23

Contrast the activity patterns of Pre-SMA and SMA cells in terms of sequence learning.

Answer 23

Pre-SMA cells exhibited higher activity for new sequences, while SMA cells showed increased activity for well-learned sequences.

Question 24

What aspect of movements might the CMA be involved in?

Answer 24

The CMA may be involved in the “emotional” aspects of movements.

Question 25

How is the CMA associated with emotional aspects of movement?

Answer 25

The CMA is interconnected with limbic areas for emotional processing and memory.

Question 26

What role does the CMA play in decision-making processes related to movements?

Answer 26

The CMA is involved in decision-making processes related to movements and serves as an entry point for limbic system influence, influencing voluntary movement.

Question 27

How is the CMA connected with the basal ganglia?

Answer 27

The CMA is linked with the basal ganglia for motor control, particularly related to the motivational pace of motor outputs.

Question 28

Issues with Cingulate Motor Cortex can Result in:

Answer 28

Affect movement initiation and coordination

Question 29

What is the size comparison between the dorsal premotor area (PMd) and the primary motor cortex (MI) in humans?

Answer 29

The dorsal premotor area (PMd) is six times larger than the primary motor cortex (MI) in humans.

Question 30

What are the major inputs to the dorsal premotor area (PMd)?

Answer 30

The major inputs to the dorsal premotor area (PMd) come from the cerebellum and other cortical areas.

Question 31

What is the main output of the dorsal premotor area (PMd)?

Answer 31

The main output of the dorsal premotor area (PMd) is the primary motor cortex.

Question 32

What is the direction-specific activity observed in cells of the dorsal premotor area (PMd)?

Answer 32

The cells in the dorsal premotor area (PMd) of the brain show a specific type of activity related to the direction of movement. Some cells are more active when the intention is to move to the left, while others are more active when the intention is to move to the right.

Question 33

What distinguishes the functional influence of the lateral premotor cortex from the primary motor cortex?

Answer 33

Stimulation of the lateral premotor cortex evokes complex movements in contrast to the primary motor cortex, which induces muscle-specific twitches.

Question 34

What is the functional significance of the lateral premotor cortex’s corticospinal projections?

Answer 34

The lateral premotor cortex’s corticospinal projections extend to the spinal cord, particularly influencing proximal musculature and inducing intricate movements beyond simple contractions.

Question 35

What does the study suggest about the impact of damage to the dorsal premotor area?

Answer 35

The study indicates that damage to the dorsal premotor area hinders the ability to form new associations between sensory cues, such as color cues, and motor actions.

Question 36

What is PMv’s (ventral premotor area) role in motor planning?

Answer 36

PMv selects hand shapes for specific tasks based on visual input from the parietal lobe.

Question 37

How does PMv determine the appropriate hand shape for objects like cylinders or knobs?

Answer 37

PMv processes visual information to decide whether a precision or power grip is suitable for the given object.

Question 38

Mirror Neurons in PMV

Answer 38

Neurons in the brain that activate both when an individual performs an action and when they observe someone else performing the same action