Brain Scanning Techniques in Cognitive Neuroscience

Brain Scanning Techniques

• Cognitive neuroscience approach uses several brain scanning techniques to study the living brain.
• Techniques include Magnetic Resonance Imaging (MRI), Functional Magnetic Resonance Imaging (fMRI), Positron Emission Tomography (PET) Scan, and Electroencephalography (EEG).

Magnetic Resonance Imaging (MRI)

• Involves passing non-harmful radio frequencies through the brain to measure interactions with brain cells.
• Transforms interactions into a detailed image of the brain (or body).
• Used to study the structure of the brain, showing location of structures inside the brain and identifying tumors and sites of brain damage.

Functional Magnetic Resonance Imaging (fMRI)

• Measures changes in activity of specific neurons during cognitive tasks (such as thinking, listening, reading).
• Uses non-harmful radio frequencies and can give detailed views of structures and functions inside the living brain.
• fMRI scans show changes in activity, unlike MRI scans which show structure only.

Positron Emission Tomography (PET) Scan

• Involves injecting a slightly radioactive solution into the blood and measuring the amount of radiation absorbed by neurons.
• Very active neurons absorb more radioactive solution than less active ones.
• Different levels of absorption are represented by colors, with red and yellow indicating maximum activity and blue and green indicating minimal activity.

Electroencephalography (EEG)

• Involves placing many electrodes on the scalp to measure changes in electrical activity at points along the scalp.
• Provides information about brain activity.

Divisions of Nervous System

• The nervous system is divided into Central Nervous System (CNS) and Peripheral Nervous System (PNS).

Central Nervous System (CNS)

• Made up of the brain and spinal cord.
• Spinal cord emerges from the bottom of the brain and carries information back and forth between the brain and the body.
• CNS is the site for complex cognitive functions, such as thinking, speaking, reading, feeling, seeing, and hearing.

Peripheral Nervous System (PNS)

• Made up of all the nerves that extend from the spinal cord.
• Carries messages to and from various muscles, glands, and sense organs located throughout the body.
• Divided into the somatic and autonomic nervous systems.

Somatic Nervous System

• Consists of a network of nerves that connect either to sensory receptors or to muscles that can be moved voluntarily.
• Controls voluntary movement.
• Nerves in the somatic nervous system contain two kinds of fibers: afferent (sensory) fibers and efferent (motor) fibers.

Autonomic Nervous System

• Regulates involuntary activities such as regulating heart rate, breathing, blood pressure, digestion, hormone secretion, and other functions.
• Usually functions without conscious effort.