Differential effects of rumination and distraction on ketamine induced modulation of resting state functional connectivity and reactivity of regions within the default-mode network
Mick Lehmann, Erich Seifritz, A Henning, Martin Walter, Heinz Böker, Milan Scheidegger, Simone Grimm
Social Cognitive and Affective Neuroscience April 13, 2016 DOI: 10.1093/scan/nsw034 via OpenAlex
Summary
Distraction and rumination are distinct ways people respond to negative thoughts and feelings. Rumination involves elevated self-focus, linked to increased resting state functional connectivity and decreased reactivity within the default mode network. The NMDA receptor antagonist ketamine reduces functional connectivity in this network, but its effects on brain responses during stimulus perception were unknown. In healthy subjects given a single ketamine dose, blood oxygenation level-dependent (BOLD) reactivity to negative emotional pictures increased specifically in the pregenual anterior cingulate cortex, not in a posterior control region. The increase was greater in subjects with low ability to use distraction during negative experiences. Ketamine may attenuate pathological increased self-focus during negative experiences.
Study at a glance
| Characteristics | Randomized controlled trial Peer reviewed |
|---|---|
| Population | Healthy subjects |
| Intervention | Ketamine |
| Dose | single ketamine administration |
| Topics | Default mode network Ketamine |
| Keywords | Rumination Neuroscience Distraction Resting State FMRI |
| Citations | 58 |
| Key finding | A single ketamine administration increased BOLD reactivity to negative stimuli in the pregenual anterior cingulate cortex, with a greater increase in subjects with low ability to use distraction. |
Abstract
Distraction and rumination are distinct response styles that determine how an individual deals with negative thoughts and feelings. Rumination is accompanied by an elevated self-focus, which is associated with increased resting state functional connectivity and decreased reactivity within the default mode network. Interestingly, the NMDA receptor antagonist ketamine reduces functional connectivity in this network, while its effects on blood oxygenation level-dependent (BOLD) responses during stimulus perception are not known. Ketamine might lead to a more variable processing of the external world with an attenuated self-focus by reducing the resting state connectivity. Here, we used an emotional picture-viewing task in combination with functional magnetic resonance imaging to test the hypothesis that a single ketamine administration to healthy subjects increases BOLD reactivity to negative stimuli. We found a region specific increase in BOLD reactivity in the pregenual anterior cingulate cortex and not in a posterior control region after ketamine compared with placebo administration. Moreover, a linear regression revealed that the increase in BOLD reactivity was more pronounced for subjects with a low ability to apply distraction during negative experiences. Our results implicate that ketamine attenuates a potentially pathological increased self-focus during negative experiences.