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

Abstract

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.

A reassessment of the pseudoneglect effect: Attention allocation systems are selectively engaged by semantic and spatial processing.

“…As described, the IPL upregulates activity in the spatially specific dorsal attention network ( Corbetta & Shulman, 2011 ; Hillis et al, 2005 ; Thiebaut de Schotten et al, 2011 ). As a result, our findings could reflect the tight link between semantic processing and the left IPL ( Gray et al, 2020 ; Humphreys & Lambon Ralph, 2015 ; Seghier, 2013 ; Seghier et al, 2010 ; Vigneau et al, 2006 ) that disproportionately increases left FPA network activity and biases the allocation of attention to the right side of visual space. This mechanism should be further explored using neuroimaging and neurostimulatory investigations.…”

“…Our interactions with them are both more frequent and varied than those we have with more abstract shapes or lines. Like words, the semantic processing of objects (e.g., labeling them, categorizing them, retrieving related information from memory) has often been associated with IPL activity lateralised to the left hemisphere ( Devereux et al, 2013 ; Gray et al, 2020 ; Vigneau et al, 2006 ). Experiments 1 and 2 explore how spatial attention interacts with the semantic processing of objects.…”

“…Indeed, a meta-analysis of neuroimaging contrasts, targeting different IPL functions reported strong evidence linking “automatic semantic processing” (e.g., reading words > nonwords, concrete > abstract words) with left, but not right, hemisphere angular gyrus activity ( Humphreys & Lambon Ralph, 2015 ). In addition, the retrieval of semantic information from episodic memory has been closely linked to left, but not right, IPL activity ( Gray et al, 2020 ) and the left angular gyrus has been identified as a semantic hub; reflecting its heteromodal response to semantic information ( Bonner et al, 2013 ; Vigneau et al, 2006 ). The potential for interaction between semantic processing and systems that govern the allocation of attention has been suggested, but not effectively measured ( Lee et al, 2004 ; Turriziani et al, 2009 ).…”

Alterations in local activity and functional connectivity in patients with postherpetic neuralgia after short-term spinal cord stimulation

“…The IPL participates in emotional expression and is related to happiness (Schmidt et al, 2020 ). The angular gyrus is both a node of the DMN and a subregion of the inferior parietal lobule (Gray et al, 2020 ). The supramarginal gyrus processes external/perceptual information, whereas the angular gyrus processes internal/conceptual information (Rubinstein et al, 2021 ).…”

Effects on brain activity after creative mathematical reasoning when considering individual differences in cognitive ability

“…Yet a third interpretation of the observed activity differences is related to semantic memory. Left lateralized brain activity in especially IFG and AG is identified as key for semantic memory processing and conceptual representations (Binder & Desai, 2011;Gray, Fry, & Montaldi, 2020;Martin & Chao, 2001). Even though mathematical reasoning is likely to recruit brain regions unique to mathematical content (Amalric & Dehaene, 2016, left AG has been found to be co-activated with lateral PFC regions, linked to semantic processing of the specific mathematical content (Amalric & Dehaene, 2016).…”