1.8 The Brain

Studying the living brain

Scientists use several tools to study brain structure and function: EEG records electrical activity via scalp electrodes; fMRI and PET scans show brain activity by tracking blood flow or glucose use; CT and MRI scans reveal structure. Lesioning studies (damaging tissue) and case studies of brain-damaged patients also reveal how regions function.

The brain's major regions

The hindbrain (medulla, pons, cerebellum) controls survival functions and balance/coordination. The midbrain relays sensory/motor info and includes the reticular formation (arousal). The forebrain includes the thalamus (sensory relay), hypothalamus (homeostasis, drives), limbic system (amygdala for emotion, hippocampus for memory), and the cerebral cortex, the seat of higher thought.

Cortex lobes and hemispheres

The cortex has four lobes: frontal (decision-making, motor cortex, Broca's area for speech), parietal (touch, somatosensory cortex), temporal (hearing, Wernicke's area for language comprehension), and occipital (vision). Hemispheric specialization: the left hemisphere favors language/logic, the right favors spatial/creative tasks; the corpus callosum connects them, enabling communication.

Key terms

Reticular formation

A network in the brainstem/midbrain that controls arousal and alertness.

Amygdala

Limbic system structure involved in processing emotions, especially fear and aggression.

Hippocampus

Limbic system structure critical for forming and consolidating new memories.

Wernicke's area

Region in the temporal lobe responsible for language comprehension.

Hemispheric specialization

Tendency for each hemisphere to perform distinct functions; left favors language/logic, right favors spatial/creative tasks.

Try an AP-style question

Which area was likely damaged?

1. Wernicke's area
2. Occipital lobe
3. Cerebellum
4. Broca's area