- The parahippocampal gyrus is a prominent structure of the medial temporal lobe, located adjacent to the hippocampus and playing a key role in memory encoding, spatial navigation, and scene recognition.
- It forms part of the limbic system and serves as a critical interface between the hippocampus and various cortical regions. Structurally, the parahippocampal gyrus includes the entorhinal cortex, perirhinal cortex, and parahippocampal cortex—each contributing uniquely to memory and sensory processing. Because of its close anatomical and functional relationship with the hippocampus, it is deeply involved in processing contextual information and laying down the spatial and temporal framework of episodic memories.
- One of the parahippocampal gyrus’s most well-characterized functions is its role in spatial memory and navigation. The parahippocampal place area (PPA), located within the posterior parahippocampal region, is specifically activated when individuals view scenes, landmarks, or environmental layouts. This region is thought to support the recognition and encoding of visual scenes and to help create internal representations—or “cognitive maps”—of an individual’s surroundings. These spatial representations are critical for navigation and orientation, both in real-world environments and in imagined or remembered spaces.
- The parahippocampal gyrus also contributes significantly to episodic memory, especially the encoding and retrieval of contextual details surrounding events. While the hippocampus binds various elements of an experience (e.g., who, what, when, where), the parahippocampal gyrus helps process the “where” component—namely, the spatial or environmental context in which an event occurred. This contextual information enhances memory precision and allows individuals to mentally reconstruct past events with rich background detail. The entorhinal cortex, in particular, serves as a major input-output gateway between the hippocampus and the neocortex, supporting memory consolidation and the transfer of information between short- and long-term memory systems.
- Damage or dysfunction of the parahippocampal gyrus can lead to deficits in spatial orientation, contextual memory, and scene recognition. Lesions in this area may result in topographical disorientation, where a person loses the ability to navigate familiar environments, despite having intact visual and motor functions. Abnormal activity in the parahippocampal region has also been linked to Alzheimer’s disease, temporal lobe epilepsy, and schizophrenia, conditions in which memory, context perception, or spatial awareness is impaired.
