Inferior Temporal & Fusiform Cortex

Anatomy

• Middle and inferior temporal gyri (BA 21, 20), fusiform gyrus (BA 37), temporal pole (BA 38).
• Fusiform face area (FFA — right-dominant) and visual word form area (VWFA — left fusiform).
• Medially, the parahippocampal gyrus and entorhinal cortex (BA 28, 35–36) form the gateway to the hippocampus.
• Blood supply: PCA (inferior temporal branches) and MCA (lateral surface).

Functions

• Ventral visual stream (“what?”): object and shape recognition.
• Face recognition and identity discrimination (FFA).
• Reading: rapid recognition of written word forms (VWFA).
• Semantic memory: knowledge of concepts and word meanings (temporal pole, ITG).
• Scene and place processing (parahippocampal place area), color processing.

Connections and chemistry

• Occipital cortex (ventral stream)
• Hippocampus and amygdala
• OFC (uncinate fasciculus)
• Inferior longitudinal fasciculus

Development

Developmental course through childhood and adolescence.

• Face-selective regions grow and specialize through childhood and adolescence.
• The VWFA emerges with learning to read (ages 5–7) and strengthens with reading experience.
• The visual word form area (VWFA) forms through learning to read: comparing adults who were illiterate, learned to read in adulthood or learned in childhood, literacy increased the left fusiform response to script and started a small competition with face processing at the same site; most changes were also seen in those who learned as adults (Dehaene et al., 2010). A cultural invention (reading) “recycles” an old visual area. B

Clinical

• ASD: reduced fusiform response to faces; related to the pattern of looking at the eye region.
• Dyslexia: VWFA hypoactivation.
• Developmental prosopagnosia.
• Temporal lobe epilepsy: behavioral and emotional symptoms, memory problems.

Treatment

This region from the perspective of medication, psychotherapy and neuromodulation. Letter badges are evidence levels.

• Dyslexia intervention increases VWFA and left temporoparietal activity; details on the IPL card. B
• In developmental prosopagnosia: compensatory strategies (voice, hair, gait and clothing cues) and awareness at school. C

Assessment

Neuropsychological tasks and measures that probe this region's function.

• Benton Facial Recognition, Cambridge Face Memory Test (child version)
• Object naming, category fluency (animal names)
• Reading speed and fluency

Lesions and damage

Clinical findings expected with damage or dysfunction.

• Prosopagnosia (right/bilateral fusiform), visual object agnosia.
• Pure alexia (left VWFA), achromatopsia.
• Temporal pole: loss of semantic memory, anomia. Bilateral anterior temporal: Klüver-Bucy syndrome.

In the model

How this structure is defined in the 3D model, and the data source.

Middle and inferior temporal, fusiform, parahippocampal and entorhinal cortex; the uncus on the medial temporal surface is shown in this color too.

References

Full citations for the card; links go to the paper (DOI) or a PubMed search.

1. Dehaene S et al. How learning to read changes the cortical networks for vision and language. Science 2010;330:1359–1364. Search PubMed