Question

A surgeon places an electrode on a portion of your brain and stimulates it. Immediately, your right wrist involuntarily twitches The doctor has most likely stimulated a portion of the ___________ area of your brain.

Short answer

The surgeon stimulated the left motor cortex.

Step-by-step solution

Identify the nature of the exercise

This is a neuroscience question that focusing on the function of the brain. The right wrist twitching suggests that the part of the brain associated with motor control has been stimulated.

Recall basic brain anatomy and functions

It's known from basic neuroscience that the left side of the brain controls the right side of the body. Also, the motor functions are controlled by the motor cortex part of the brain.

Associate the brain area with symptoms

Since the right wrist is twitching, and it's known that the left side of the brain controls the right side of the body and the motor cortex is responsible for motor functions, we conclude that the doctor has stimulated the motor cortex on the left side of the brain.

Key concepts

Motor Cortex

The motor cortex is a key player in controlling voluntary movements. It primarily resides in the frontal lobe of the brain, occupying a strip known as the precentral gyrus. This crucial area can be thought of as the company headquarters for movement orders in the brain. When you decide to pick up a pencil, it's the motor cortex that sends signals down the spinal cord to your muscles, coordinating the required movement.

There are two main regions within the motor cortex: the primary motor cortex and the premotor cortex. The primary motor cortex is tasked with generating neural impulses that control the execution of movement, while the premotor cortex is involved in planning these movements. In our exercise, the stimulation of the motor cortex leads to involuntary muscle twitches, such as the right wrist twitching when the left motor cortex is activated. This is because the motor cortex on each side of the brain is responsible for movements on the opposite side of the body.

Brain Anatomy

Understanding brain anatomy is essential to grasp how the motor cortex functions. The brain is divided into two hemispheres, left and right, which are responsible for different aspects of cognition and motor control. Each hemisphere controls the opposite side of the body, a phenomenon known as contralateral control.

Within each hemisphere, the motor cortex is just one of many important areas that have specific functions.

• The frontal lobe, home to the motor cortex, is key for voluntary movements and complex decision-making.
• The parietal lobe processes sensory information and spatial navigation.
• The occipital lobe is primarily responsible for visual processing.
• The temporal lobe manages auditory information and memory.

These different areas work together to perform complex tasks that require both thought and action, such as writing, dancing, or driving a car.

Neuroscientific Function

Neuroscientific functions encompass a broad range of activities performed by the brain and nervous system, highlighting the intricate design and capability of our neural networks. The brain functions like a powerful supercomputer, processing information from the environment and coordinating responses throughout the body.

Specialized regions in the brain manage different functions:

• Motor functions, as discussed, originate from the motor cortex.
• Sensory functions process external stimuli, with specific areas dedicated to processing visual, auditory, and tactile information.
• Cognitive functions such as thinking, memory, and problem-solving are distributed across various brain regions.
• Basic regulatory functions like heartbeat and breathing are managed by the brainstem.

In the context of our exercise, when a device like an electrode stimulates a specific brain region, it triggers a corresponding function, showcasing the brain's remarkable precision and coordination in managing what we think, feel, and do.