Variable Presence of an Evolutionarily New Brain Structure is Related to Trait Impulsivity

Ethan H Willbrand; Samira A Maboudian; Matthew V Elliott; Gabby M Kellerman; Sheri L Johnson; Kevin S Weiner

doi:10.1016/j.bpsc.2024.11.015

Variable Presence of an Evolutionarily New Brain Structure is Related to Trait Impulsivity

Biol Psychiatry Cogn Neurosci Neuroimaging. 2024 Nov 27:S2451-9022(24)00352-5. doi: 10.1016/j.bpsc.2024.11.015. Online ahead of print.

Authors

Ethan H Willbrand¹, Samira A Maboudian², Matthew V Elliott³, Gabby M Kellerman³, Sheri L Johnson³, Kevin S Weiner⁴

Affiliations

¹ Medical Scientist Training Program, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA.
² Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, USA; Department of Neuroscience, University of California, Berkeley, Berkeley, CA, USA.
³ Department of Psychology, University of California, Berkeley, Berkeley, CA, USA.
⁴ Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, USA; Department of Neuroscience, University of California, Berkeley, Berkeley, CA, USA; Department of Psychology, University of California, Berkeley, Berkeley, CA, USA. Electronic address: [email protected].

PMID: 39613159
DOI: 10.1016/j.bpsc.2024.11.015

Abstract

Background: Impulsivity is a multidimensional construct reflecting poor constraint over one's behaviors. Clinical psychology research identifies separable impulsivity dimensions that are each unique transdiagnostic indicators for psychopathology. Yet, despite this apparent clinical importance, the shared and unique neuroanatomical correlates of these factors remain largely unknown. Concomitantly, neuroimaging research identifies variably present human brain structures implicated in cognition and disorder: the folds (sulci) of the cerebral cortex located in the latest developing and most evolutionarily expanded hominoid-specific association cortices.

Methods: We tethered these two fields to test whether variability in one such structure in anterior cingulate cortex (ACC)-the paracingulate sulcus (PCGS)-was related to individual differences in trait impulsivity. 120 adult participants with internalizing or externalizing psychopathology completed a magnetic resonance imaging scan and the Three-Factor Impulsivity Index. Using precision imaging techniques, we manually identified the PCGS, when present, and acquired quantitative folding metrics (PCGS length and ACC local gyrification index).

Results: Neuroanatomical-behavioral analyses revealed that participants with leftward or symmetrical PCGS patterns had greater severity of Lack of Follow Through (LFT)-which captures inattention and lack of perseverance-than those with rightward asymmetry. Neuroanatomical-functional analyses identified that the PCGS co-localized with a focal locus found in a neuroimaging meta-analysis on a feature underlying LFT. Both quantitative folding metrics did not relate to any impulsivity dimension.

Conclusions: This study advances understanding of the neuroanatomical correlates of impulsivity and establishes the notion that the topographical organization of distinct, hominoid-specific cortical expanses underlie separable impulsivity dimensions with robust, transdiagnostic implications for psychopathology.

Keywords: Cingulate cortex; Impulsivity; Neuroanatomy; Neuroimaging; Psychopathology; Transdiagnostic.