Perirhinal Cortex — Function, Location & Quiz
Perirhinal cortex helps answer a narrow but familiar question: have I encountered this item before? Its recognition signal is graded, growing with familiarity, and differs from the sharper recollective recovery of contextual detail associated with hippocampal processing.
It also sits on the object-information route into the medial temporal memory system. Ventral visual identity signals pass through perirhinal cortex toward entorhinal cortex, allowing a known thing to be linked with where and when it appeared.
Test this anatomy in the Brain Regions Quiz or open the interactive 3D brain model.
Location and anatomical map
Item recognition and familiarity-based memory signaling.
Atlas category: cortical. Brodmann areas or landmark: BA 35, 36.
Functions
- Item recognition — 'have I seen this before?'
- Familiarity signaling — gradual, graded strength-of-memory signal
- Object identity and visual object knowledge
Pathways and connections
- Perirhinal → Entorhinal cortex (object info to hippocampus via 'what' stream)
- Perirhinal ← Ventral visual stream (object identity from 'what' pathway)
Clinical relevance
- Damage impairs familiarity but may spare recollection (hippocampal process)
- Selective perirhinal lesions rare in humans but confirmed in animal models
Key facts
- Two-Process Theory: perirhinal cortex = familiarity, hippocampus = recollection
- Daselaar (2006): rhinal cortex shows GRADUAL signal for familiarity (graded confidence)
- Hippocampus shows SHARP, threshold-like signal for recollection (all-or-nothing)
Exam tip
Perirhinal = familiarity (gradual signal). Hippocampus = recollection (sharp signal). Daselaar 2006 is the key study.
Common questions
What does the perirhinal cortex do?
It supports item recognition, object knowledge and graded familiarity—the sense that something has been encountered even without recovery of its original context.
How is perirhinal familiarity different from hippocampal recollection?
Familiarity is a gradual strength signal for the item itself; recollection is a more threshold-like recovery of contextual details about an episode.
Where does perirhinal cortex send object information?
It projects toward entorhinal cortex, which provides a major interface with the hippocampus, forming the medial temporal “what” route into episodic memory.