Neural correlates of working memory deficits and associations to response inhibition in obsessive compulsive disorder

Abstract

Previous research in patients with obsessive-compulsive disorder (OCD) has indicated performance decrements in working memory (WM) and response inhibition. However, underlying neural mechanisms of WM deficits are not well understood to date, and empirical evidence for a proposed conceptual link to inhibition deficits is missing.We investigated WM performance in a numeric n-back task with four WM load conditions during functional Magnetic Resonance Imaging (fMRI) in 51 patients with OCD and 49 healthy control participants who were matched for age, sex, and education. Additionally, a stop signal task was performed outside the MRI scanner in a subsample.On the behavioral level, a significant WM load by group interaction was found for both accuracy (p < 0.02) and reaction time measures (p < 0.03), indicating increased reaction times as well as reduced accuracy specifically at high WM load (3-back) in patients with OCD. Whole-brain analyses of fMRI-data identified neural correlates of a load-dependent WM decrement in OCD in the supplementary motor area (SMA) and the inferior parietal lobule (IPL). Within the OCD sample, SMA-activity as well as n-back performance were correlated with stop signal task performance.Results from behavioral and fMRI-analyses indicate a reduced WM load-dependent modulation of neural activity in OCD and suggest a common neural mechanism for inhibitory dysfunction and WM decrements in OCD.

MRI-Based Multimodal Approach to the Assessment of Clinical Symptom Severity of Obsessive-Compulsive Disorder

“…Also, it was reported that continuous psychiatric symptoms more than five years give rise to the increased brain activation and abnormal functional connectivity, inducing the poor memory performance. 8 Another interesting finding in our study is that patients with OCD showed increased GM volumes in the Hip and OFC ( Figure 5A). Hippocampal region and OFC play an essential role in memory encoding and retrieval.…”

“…There are many other studies [ 31 - 35 ] demonstrating that alteration of Cd volume and abnormal functional activation are associated with symptom severity in OCD. Also, it was reported that continuous psychiatric symptoms more than five years give rise to the increased brain activation and abnormal functional connectivity, inducing the poor memory performance [ 8 ].…”

“…Especially, OCD behaviors involve the cognitive dysfunction and poor memory. There are many neuro-functional studies [ 3 - 8 ] on the abnormal brain activity with memory dysfunction, particularly in the strategic memory processing [ 3 - 5 ]. In general, patients with OCD tend to over-focus on details and miss the larger context, leading to memory impairment [ 6 , 7 ].…”

“…Recently, Moon et al [ 7 ] used a combined study with functional magnetic resonance imaging (fMRI) and voxel based morphometry (VBM) to demonstrate the identical brain areas showing low functional activities and brain volume reduction. From the knowledge of the previous studies [ 3 , 4 , 6 - 8 , 12 , 13 ], we assumed that altered brain activity and functional connection and morphometric abnormality are closely associated with OCD symptom and its severity.…”

Emotional interference under low versus high executive control

“…Emotional processing is adaptively modulated by executive control in healthy participants (Iordan, Dolcos, & Dolcos, ; Okon‐Singer, Lichtenstein‐Vidne, & Cohen, ). In accordance with this, several psychological disorders are associated with alterations in executive control functions such as performance monitoring and conflict processing (Endrass & Ullsperger, ; Grützmann et al, ; Moser, Moran, Schroder, Donnellan, & Yeung, ; Proudfit, Inzlicht, & Mennin, ) or working memory (Heinzel et al, ). Executive dysfunction, as indexed by increased error monitoring, is also found in healthy participants with habitually increased negative affect or anxiety (Hajcak, McDonald, & Simons, , ).…”