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

Area of Science:

• Neuroscience
• Psychology
• Neuroimaging

Background:

• Impulsivity is a key transdiagnostic indicator for psychopathology, with distinct dimensions.
• Neuroanatomical correlates of these impulsivity dimensions are largely unknown.
• Cortical sulci in association cortices are implicated in cognition and disorder.

Purpose of the Study:

• To investigate the relationship between the paracingulate sulcus (PCGS) in the ACC and trait impulsivity.
• To determine if PCGS variability is associated with specific impulsivity dimensions.

Main Methods:

• 120 adults with psychopathology underwent MRI scans and completed the Three-Factor Impulsivity Index.
• Manual identification of the PCGS and quantitative folding metrics (length, gyrification) were acquired.
• Neuroanatomical-behavioral and neuroanatomical-functional analyses were performed.

Main Results:

• Leftward or symmetrical PCGS patterns were associated with higher Lack of Follow Through (LFT) severity.
• The PCGS colocalized with a brain region implicated in LFT.
• Quantitative folding metrics did not correlate with any impulsivity dimension.

Conclusions:

• The topographical organization of the PCGS relates to specific impulsivity dimensions.
• This finding advances understanding of the neuroanatomical underpinnings of impulsivity and psychopathology.
• Distinct cortical folding patterns may underlie separable impulsivity dimensions with clinical relevance.