BRAIN SCANS FOR PSYCHOLOGY STUDENTS - CT, MRI, fMRI, PET - Neuroscience

Scientific concepts, discoveries, and nature phenomena presented

• Non-invasive brain imaging for psychology/neuroscience
  • How psychologists/neuroscientists “look inside” the brain without surgery.
  • Brain scans can be used to study:
    • Structure (anatomy), such as areas affected by stroke or lesions
    • Function (activity), such as which brain regions activate during tasks

Four main brain scan types (how they work and what they measure)

CT (Computed Tomography) — structural

• X-ray-based imaging.
• Produces horizontal slice (“cut”) images of the brain.
• Uses many X-ray beams combined by computer algorithms to form an image.
• Etymology: tomography comes from Greek “to cut.”

MRI (Magnetic Resonance Imaging) — structural

• Uses a magnetic field rather than X-rays.
• Hydrogen molecules in the brain respond to the magnetic field and emit signals recorded by the scanner.
• Reported to provide more accurate structural pictures than CT.
• Can be adapted for functional imaging via fMRI.

fMRI (Functional MRI) — functional

• Uses the same basic technique as MRI, but takes multiple scans while a person performs an action/task.
• Identifies which brain regions activate during specific functions.
• The “f” stands for functional.

PET (Positron Emission Tomography) — functional

• Described as invasive due to radioactivity.
• Involves injecting a radioactive substance.
• The tracer is described as a form of glucose:
  • travels through the bloodstream to the brain
  • accumulates in active brain regions (associated with increased metabolic activity / oxygenated blood flow)
• Releases positrons, which the scanner detects (“positron emission”).
• Produces a multicolored heat-map-like image indicating functional activity.
• Limitations noted:
  • not used for children or pre-menopausal women (due to radioactivity)
• The basis of detection emphasizes: “Positron” + “emission.”

Cost and practical considerations

• Brain scanning machines are expensive (over $1 million for a single machine, excluding additional costs like operation, training, and maintenance).

Psychological/neuroscientific significance

• Brain scans have helped advance understanding of the neural basis of key functions, including:
  • language
  • perception
  • memory

Researchers or sources featured

• No specific researchers, institutions, or published sources are named in the provided subtitles.