Information content best characterises the hemispheric selectivity of the inferior parietal lobe: a meta-analysis

Our understanding of the inferior parietal lobe (IPL) remains challenged by inconsistencies between neuroimaging and neuropsychological perspectives. To date, others assume that hemispheric specialisation of the IPL is linked with the type of processing; attention processing in the right hemisphere; memory retrieval and semantic judgement in the left hemisphere. Here, we provide compelling evidence associating the type of information being processed with the recruitment of each hemisphere's IPL. In a meta-analysis, we classify 121 previous fMRI reports of IPL activity arising from episodic memory retrieval, according to the type of information that characterises each fMRI contrast. We demonstrate that the left IPL is more consistently associated with retrieval of the semantic (95% of eligible contrasts) than perceptual aspects of memory (83%). In contrast, the right IPL is more consistently associated with the retrieval of perceptual (97%), than semantic aspects of memory (43%). This work revises assumptions of how the IPL contributes to healthy cognition and has major implications for IPL-related neuropsychological deficits.