The temporal lobe sits below the lateral fissure (also called the Sylvian fissure), on each side of the brain. It is functionally rich: it hosts auditory cortex, the hippocampus (we met in Stage 6), the amygdala (also Stage 6), and the regions responsible for auditory comprehension of language. It is also the lobe most likely to produce the strangest seizure phenomena in clinical neurology.
The primary auditory cortex sits on the superior temporal gyrus. It receives input from the cochlea via the medial geniculate nucleus of the thalamus. Higher-order auditory areas extending forward and downward process complex sound features, including the recognition of speech as speech.
On the left side in most people, in the posterior superior temporal gyrus, lies Wernicke's area — the seat of language comprehension. Damage produces Wernicke's aphasia, also called receptive aphasia: fluent but meaningless speech and an inability to understand language. The patient speaks with normal prosody and grammatical structure, but the content is empty or nonsensical, and they cannot follow what is said to them. This contrasts with Broca's aphasia, in which speech is effortful, halting, and grammatically simplified, but comprehension is relatively spared.
The temporal lobe also processes the recognition of faces (the fusiform face area in the right inferior temporal cortex), objects, and meaning. It integrates auditory, visual, and emotional information into a unified semantic representation of the world.
Temporal lobe epilepsy deserves a brief introduction here. Seizures originating in the medial temporal lobe — particularly in the hippocampus, parahippocampal gyrus, and amygdala — can produce a remarkable variety of phenomena. Patients describe déjà vu (a strong sense of having experienced this exact moment before), jamais vu (the eerie sense that familiar surroundings are unfamiliar), religious or spiritual experiences, autobiographical memory flashbacks, olfactory hallucinations (often described as burning rubber or other unpleasant smells), and changes in the felt quality of reality.
When you read about Dostoyevsky's epilepsy and his pre-seizure ecstatic states — moments of intense joy and meaningfulness that he treasured despite the seizures that followed — you are reading about the temporal lobe. Joan of Arc's visions have been argued to have a similar substrate. The line between the religious, the artistic, and the epileptic in these accounts is one that neurology has not entirely settled.
Hold the territory. The temporal lobe is rich. It carries hearing, language comprehension, memory, emotion, face recognition, and — when it misfires — some of the most phenomenologically striking experiences in clinical medicine.