Module 2: The Brain – Structure and Function

Main Structures of the Brain

• Hindbrain

• Midbrain

• Forebrain

Hindbrain

Basic life support, relay info from spinal cord.

Midbrain

Relay station for sensory and motor information.

Forebrain

Main area for cognition—focus here.

Forebrain Subsections

• Subcortical Structures

• Cortical Structures (Cerebral Cortex)

Subcortical Structures

• Thalamus

• Hypothalamus

• Hippocampus

• Amygdala

Thalamus

Sensory relay station; integrates sensory info.

Hypothalamus

Regulates homeostasis (hunger, thirst, temperature, arousal, emotion).

Hippocampus

Learning and memory; damage → amnesia, esp. new memory formation.

Amygdala

Emotion, aggression, emotional memory; modulates strength of emotional memories.

Cortical Structures (Cerebral Cortex)

• Divided into four lobes (in both hemispheres)

• Corpus Callosum

Divided into four lobes (in both hemispheres)

• Frontal Lobe

• Parietal Lobe

• Occipital Love

• Temporal Lobe

Frontal Lobe

Motor control, planning, decision-making, working memory, executive function.

Parietal Lobe

Spatial processing, attention, somatic sensory cortex (touch, pain, temperature).

Occipital Lobe

Visual processing

Temporal Lobe

Auditory processing, memory (close to hippocampus/amygdala).

Corpus Callosum

• Connects the two cerebral hemispheres—critical for inter-hemispheric communication.

Localization of Function

• Phrenology (Gall)

• Double Dissociation

• Lesion Studies

• Penfield’s Montreal Procedure

Phrenology (Gall)

Early, now-discredited idea that specific traits are localized to bumps on the skull.

Double Dissociation

Demonstrates independent brain functions (e.g., Broca’s area—production vs. Wernicke’s—comprehension).

Lesion Studies

• Studying patients with localized brain damage to identify function of specific areas.

• Example: Damage to Broca’s = impaired speech production; Wernicke’s = impaired comprehension.

Penfield’s Montreal Procedure

Stimulated exposed brain areas in conscious patients to map sensory/motor cortices.

Brain Imaging Techniques

• Static Imaging

• Dynamic/Functional Imaging

Static Imaging

• CAT Scan

• MRI

Dynamic/Functional Imaging

• EEG/ERP

• PET

• fMRI

• Subtraction Technique

CAT Scan

X-ray, shows brain structure.

MRI

More detailed structure, no radiation, shows tissue differences.

EEG/ERP

Measures electrical activity via scalp electrodes (good temporal resolution, poor spatial).

PET

Measures metabolism/blood flow using radioactive tracers.

fMRI

Measures BOLD (Blood Oxygenation Level Dependent) signal—shows areas active during cognitive tasks.

Subtraction Technique (esp. fMRI)

Compare brain activity in task vs. baseline to isolate activity for specific processes.