Causal involvement of the left angular gyrus in higher functions as revealed by transcranial magnetic stimulation: a systematic review

Abstract

Transcranial magnetic stimulation (TMS) is a non-invasive technique that can transiently interfere with local cortical functioning, thus enabling inferences of causal left AG involvement in higher functions from experimentation with healthy participants. Here, we examine 35 studies that measure behavioural outcomes soon after or during targeting TMS to the left AG, by design and as documented by individual magnetic resonance images, in healthy adult participants. The reviewed evidence suggests a specific causal involvement of the left AG in a wide range of tasks involving language, memory, number processing, visuospatial attention, body awareness and motor planning functions. These core findings are particularly valuable to inform theoretical models of the left AG role(s) in higher functions, due to the anatomical specificity afforded by the selected studies and the complementarity of TMS to different methods of investigation. In particular, the variety of the operations within and between functions in which the left AG appears to be causally involved poses a formidable challenge to any attempts to identify a single computational process subserved by the left AG (as opposed to just outlining a broad type of functional contribution) that could apply across thematic areas. We conclude by highlighting directions for improvement in future experimentation with TMS, in order to strengthen the available evidence, while taking into account the anatomical heterogeneity of this brain region.

Spontaneous brain activity in patients with central retinal artery occlusion: a resting-state functional MRI study using machine learning

“…Injuries to the posterior parietal cortex can result in temporary or lasting visuomotor impairments impacting hand-eye coordination and spatial navigation [22]. Furthermore, the functionality of the bilateral angular gyrus is intricately linked to the default mode network (DMN), attention, and spatial cognition [23]. Research has indicated that lesions in the left angular gyrus leading to finger agnosia will consistently result in left-right disorientation [24].…”

Language Impairment in Vascular Dementia: A Clinical Review

“…41,42 This structure is also involved in other cognitive functions, such as memory retrieval, language (reading, writing, comprehension), numerical processing, spatial cognition, attention, and motor planning. 43 Strategic infarcts of the left angular gyrus can cause Gerstmann syndrome (acalculia, right-left disorientation, agraphia, digital agnosia) as well as disorders of language and praxis. 44,45 The role of the thalamus, which is neuroanatomically connected to the dorsolateral prefrontal cortex, extends beyond relaying sensory information to the cortex.…”