Topic 12- Premotor Cortex Flashcards
(38 cards)
Three Basic Function of Premotor Cortex
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
What is the premotor cortex?
A set of interconnected areas in the frontal lobe, positioned rostral to the primary motor cortex (M1).
How is the premotor cortex divided?
The premotor cortex is divided into “lateral” and “medial” regions.
Where is the premotor cortex located in relation to the primary motor cortex?
The premotor cortex is positioned in front (anterior) of the primary motor cortex.
Describe the spatial relationship between the premotor cortex and the primary motor cortex.
The frontal regions of the premotor cortex are rostral (toward the front) relative to the primary motor cortex (M1).
What are the connectivity patterns of premotor areas?
Premotor areas have extensive connections with the primary motor cortex (M1) and direct projections to the spinal cord.
How do premotor areas select movements?
Premotor areas use information from other regions to select movements appropriate to the context of a required action.
What is the primary function of premotor areas?
Premotor areas are primarily concerned with planning movements.
When are premotor areas active?
Premotor areas are active during the preparation of movement
Medial premotor area
1) Supplementary motor area (SMA)
2) preSMA
3) Cingulate motor area (CMA)
Where is the SMA (Supplementary Motor Area) located?
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.
Describe the location of the Cingulate Motor Area.
Located caudally, inferior to the supplementary and pre-supplementary motor areas, positioned below the supplementary motor area near the cingulate sulcus.
What role does stimulation of medial premotor areas play in movements?
Stimulation of medial premotor areas, induces bilateral movements and is essential for coordinating movements on both sides of the body.
What is the SMA’s role?
Crucial for orchestrating complex, sequential motor tasks and is specifically involved in learned sequences of movements
Observations in Healthy Individuals: SMA
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.
Patients with SMA Lesions
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.
What is the clinical correlation between Basal Ganglia damage and the ability to perform sequences of movements?
Patients with Basal Ganglia damage often struggle with executing sequential movements, as seen in conditions like Parkinson’s disease.
How are the premotor areas, including the Supplementary Motor Area (SMA), interconnected with the Basal Ganglia?
Premotor areas, including the SMA, receive substantial input from the basal ganglia, forming highly interconnected circuits that play a crucial role in motor planning.
How does the interconnected network between SMA and Basal Ganglia contribute to motor planning and coordination?
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.
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.
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.
What is the specific role of the Pre-Supplementary Motor Area (Pre-SMA) in motor sequences?
Pre-SMA focuses on learning new motor sequences.
Contrast the activity patterns of Pre-SMA and SMA cells in terms of sequence learning.
Pre-SMA cells exhibited higher activity for new sequences, while SMA cells showed increased activity for well-learned sequences.
What aspect of movements might the CMA be involved in?
The CMA may be involved in the “emotional” aspects of movements.
