Psych 101

Module 4: Tools of Discovery — Having Our Head Examined

Main idea: Neuroscientists study how the brain produces our behaviors, thoughts, and feelings by examining brain structure and activity.

Early Brain Research

  • Brain damage helped scientists figure out which areas control certain functions.

  • Left brain → right side of body

  • Right brain → left side of body

  • Damage to the back of the brain can disrupt vision.

  • Damage to the left-front brain can cause speech problems.

  • Scientists can also stimulate or lesion specific brain areas and observe the effects.

Brain Research Techniques

Technique

What it does

EEG

Electrodes on the scalp measure the brain's electrical activity/brain waves.

PET

Uses radioactive glucose to show which brain areas are using the most energy.

MRI

Uses magnetic fields + radio waves to create detailed images of brain structure/anatomy.

fMRI

Tracks changes in blood flow/oxygen to show which brain areas are active.

fNIRS

Uses infrared light to detect brain activity through changes in blood.

Important Terms

  • Lesion: Intentionally destroying or damaging brain tissue to observe how it affects behavior/function.

  • EEG: Measures electrical activity in the brain.

  • PET: Shows brain activity by tracking glucose use.

  • MRI: Shows detailed brain structure.

  • fMRI: Shows brain function by tracking blood flow.

Key Differences to Remember

  • EEG = electrical activity

  • PET = glucose/energy use

  • MRI = brain structure

  • fMRI = brain activity/function

  • fNIRS = infrared light + blood activity

Neuroimaging & the Mind

  • Brain scans can show which areas become active during activities such as thinking, feeling pain, experiencing rejection, listening to sounds, or feeling happiness.

  • fMRI research has even been able to identify which of several mental tasks someone was performing with about 80% accuracy.

  • However, scientists warn against “neurohype”—exaggerating what brain scans can tell us, such as claiming they can reliably detect lies or predict crime.

WEIRD Populations

WEIRD = Western, Educated, Industrialized, Rich, Democratic.

  • Much neuroscience research has focused on WEIRD populations.

  • New mobile technologies, such as fNIRS, allow researchers to study a wider variety of populations.

Big Brain Research Projects

Large international projects use brain-imaging technology to map brain connections and study:

  • Brain development

  • Mental health

  • Intelligence

  • Cognition

  • Thinking speed

  • Substance use

Quick memory trick:
PET = fuel 🍬
MRI = structure 🧠
fMRI = function 🔥
EEG = electricity ⚡

Module 5: Brain Regions and Structures — Knowt Summary

🧠 LOQ 5-1: What are the hindbrain, midbrain, and forebrain?

The brain has 3 main divisions:

  • Hindbrain → controls basic survival functions

    • Breathing

    • Heartbeat

    • Sleep

    • Arousal

    • Coordination

    • Balance

  • Midbrain → connects the hindbrain and forebrain

    • Controls some movement

    • Helps transmit information for seeing and hearing

  • Forebrain → handles complex functions

    • Thinking and decision-making

    • Sensory and associative functions

    • Voluntary movement

Key idea: Brain structures have evolved to match an animal's environment. Humans have especially developed forebrains, while predatory sharks have well-developed hindbrains.

🧩 Brainstem

The brainstem is the brain's innermost region and an extension of the spinal cord.

It includes:

  • Medulla

  • Pons

  • Midbrain

Medulla

  • Controls essential automatic functions:

    • Heartbeat

    • Breathing

  • These functions can continue even without conscious thought.

Pons

  • Helps coordinate movement

  • Helps control sleep

Brainstem crossover

  • Most nerves cross over at the brainstem.

  • Left brain → right side of body

  • Right brain → left side of body

🎯 Thalamus

The thalamus is located on top of the brainstem.

Think of it as the brain's sensory relay station.

  • Receives information from all senses except smell

  • Sends sensory information to the appropriate areas of the brain:

    • Vision

    • Hearing

    • Taste

    • Touch

  • Also sends some responses toward the medulla and cerebellum

Memory trick:
Thalamus = Traffic hub for the senses 🚦

⚡ Reticular Formation

The reticular formation is a network of nerves running through the brainstem from the spinal cord toward the thalamus.

Functions:

  • Filters incoming sensory information

  • Relays important information to other brain areas

  • Controls arousal and alertness

Example: It helps you stay awake and alert when necessary.

  • Stimulating it → can cause an animal to become awake and alert

  • Severing it → can cause coma

⭐ Quick Review

Hindbrain = survival
Midbrain = movement + seeing/hearing
Forebrain = complex thinking + voluntary actions
Medulla = breathing + heartbeat
Pons = movement + sleep
Thalamus = sensory relay
Reticular formation = filtering + arousal
Brainstem = automatic functions + crossover point