Impairment of Visual Fixation and Preparatory Saccade Control in Borderline Personality Disorder With and Without...

Borderline personality disorder (BPD) is associated with heightened impulsivity, evidenced by increased substance abuse, self-harm, and suicide attempts. Addressing impulsivity in individuals with BPD is a therapeutic objective, but its underlying neural basis in this clinical population remains unclear, partly due to its frequent comorbidity with attention-deficit/hyperactivity disorder (ADHD).

We used a response inhibition paradigm-the interleaved pro-/antisaccade task-among adolescents diagnosed with BPD with and without comorbid ADHD (n = 25 and n = 24, respectively) during concomitant video-based eye tracking. We quantified various eye movement response parameters reflective of impulsive action during the task, including delay to fixation acquisition, fixation breaks, anticipatory saccades, and direction errors with express saccade (saccade reaction time: 90-140 ms) and regular saccade latencies (saccade reaction time > 140 ms).

Individuals with BPD exhibited deficient response preparation, as evidenced by reduced visual fixation on task cues and greater variability of saccade responses (i.e., saccade reaction time and peak velocity). The ADHD/BPD group shared these traits and made more anticipatory responses and direction errors with express saccade latencies and reduced error correction.

Saccadic deficits in BPD and ADHD/BPD stemmed not from an inability to execute antisaccades but rather from inadequate preparation for the upcoming task set. These distinctions may arise due to abnormal signaling in cortical areas like the frontal eye fields, posterior parietal cortex, and anterior cingulate cortex. Understanding these mechanisms could provide insights into targeted interventions focusing on task set preparation to manage response inhibition deficits in BPD and ADHD/BPD.