The effects of perseveration in Obsessive Compulsive Disorder on semantic satiation and dissociative doubt

Individuals with obsessive-compulsive disorder (OCD) exhibit perseverative
behaviours, like checking, to reduce uncertainty, but perseveration
paradoxically enhances uncertainty. The crucial question is how perseveration
breeds dissociative uncertainty. Findings on inhibition of *spreading of
activation* may be relevant. When a stimulus (e.g. apple) is processed,
semantically-related concepts (e.g. banana) become more accessible. However,
when a stimulus is repeatedly processed, spreading of activation is disrupted.
This leads to semantic satiation; the accessibility of semantically related
stimuli is diminished. OC-like repetitive behaviour (like checking) may also
interfere with spreading of activation of semantic related concepts, thereby
reducing access to the meaning of that behaviour. This may result in the
ambivalent uncertainty experienced by OCD patients (e.g., *I can see the switch
is off, but it feels fuzzy and unreal*). In a former study was found that when
healthy participants engaged in perseverative checking, semantic satiation was
induced and they experienced dissociative uncertainty. The present study will
further examine these effects of perseveration in patients with OCD. The first
part of the study aims to determine the effects of real-life clinical
perseverative behaviour on dissociative uncertainty in OCD patients. In the
second part of the study, OCD patients and matched controls will participate in
a perseveration task. In this study will be investigated whether OCD patients
report more dissociative uncertainty and display a higher level of semantic
satiation after perseveratively repeating words than healthy controls.
Moreover, we want to study whether OCD patients differ from healthy controls
with respect to their intolerance of this dissociative uncertainty.

Part 1:
Primary objective 1: Will OCD patients experience dissociative feelings during
clinical perseveration?

Part 2:
Primary objective 2: Will OCD patients report more dissociative uncertainty
after perseveratively repeating words than healthy controls? Primary objective
3: Will OCD patients display a higher level of semantic satiation after
perseveratively repeating words than healthy controls? Primary objective 4: Are
speed of relatedness judgements and feelings of dissociative uncertainty
positively correlated? Primary objective 5: If dissociative uncertainty occurs,
will OCD patients differ from healthy controls with respect to their
intolerance of this dissociative uncertainty?

Part 1 and Part 2: Primary objective 6: Are the levels of dissociative
uncertainty that are reported by OCD patients in the first part (after clinical
perseveration) and the second part (after perseveratively repeating words)
positively correlated?

Part 1: Within subjects design, with one independent variable: Condition
(perseveration/non perseveration).

Part 2: Experimental mixed within-between subjects design, with three
independent variables: Condition (perseveration/non perseveration), Relatedness
(words related/words unrelated) and Group (OCD patients/ healthy controls).

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Participation in this study will not put the participant at risk for any harm
or danger. This study will consist of a set of questionnaires which
participants have to fill out at the laboratory and will take approximately 35
minutes, a questionnaire which participants have to fill out at home and
participants will be asked to participate in a task in which they have to
repeat words and have to respond to harmless tones. Benefits of the studies are
that it can provide new insight into the possible mechanisms by which OCD is
maintained; how compulsive perseveration leads to a vicious circle of doubt and
dissociation. The findings may add to the theoretical rationale for current
treatments in OCD, like Exposure and Response Prevention.