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Corollary Discharge Failure in an Oculomotor Task Is Related to Delusional Ideation in Healthy Individuals.

Malassis R, Del Cul A, Collins T - PLoS ONE (2015)

Bottom Line: Predicting the sensory consequences of saccadic eye movements likely plays a crucial role in planning sequences of saccades and in maintaining visual stability despite saccade-caused retinal displacements.The double-step task measured predictive activity in motor control, and the in-flight displacement task measured predictive activity in trans-saccadic visual perception.We also propose that this difference in results between the perceptual and the motor tasks may point to a dissociation between corollary discharge for perception and corollary discharge for action.

View Article: PubMed Central - PubMed

Affiliation: Laboratoire Psychologie de la Perception, Université Paris Descartes & CNRS, Paris, France.

ABSTRACT
Predicting the sensory consequences of saccadic eye movements likely plays a crucial role in planning sequences of saccades and in maintaining visual stability despite saccade-caused retinal displacements. Deficits in predictive activity, such as that afforded by a corollary discharge signal, have been reported in patients with schizophrenia, and may lead to the emergence of positive symptoms, in particular delusions of control and auditory hallucinations. We examined whether a measure of delusional thinking in the general, non-clinical population correlated with measures of predictive activity in two oculomotor tasks. The double-step task measured predictive activity in motor control, and the in-flight displacement task measured predictive activity in trans-saccadic visual perception. Forty-one healthy adults performed both tasks and completed a questionnaire to assess delusional thinking. The quantitative measure of predictive activity we obtained correlated with the tendency towards delusional ideation, but only for the motor task, and not the perceptual task: Individuals with higher levels of delusional thinking showed less self-movement information use in the motor task. Variation of the degree of self-generated movement knowledge as a function of the prevalence of delusional ideation in the normal population strongly supports the idea that corollary discharge deficits measured in schizophrenic patients in previous researches are not due to neuroleptic medication. We also propose that this difference in results between the perceptual and the motor tasks may point to a dissociation between corollary discharge for perception and corollary discharge for action.

No MeSH data available.


Related in: MedlinePlus

Saccade gain in the double-step task.Vertical and horizontal endpoints of first and second saccades in the double-step tasks.
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pone.0134483.g003: Saccade gain in the double-step task.Vertical and horizontal endpoints of first and second saccades in the double-step tasks.

Mentions: Saccade gain (saccade amplitude / target eccentricity) was more accurate in the visually-guided task than in the memory-guided task, both for first saccades (0.95±0.15° versus 0.87±0.20°, respectively) and second saccades (0.97±0.17° versus 0.78±0.17°, respectively). The overall difference between visually- and memory-guided tasks was significant (F(1,40) = 21.6, p<0.001). In the visually-guided task, first and second saccade gains were comparable, whereas in the memory-guided task, second saccade gain was smaller than first saccade gain (F(1,40) = 12.2, p<0.001). Fig 3 depicts the saccade endpoints for both conditions.


Corollary Discharge Failure in an Oculomotor Task Is Related to Delusional Ideation in Healthy Individuals.

Malassis R, Del Cul A, Collins T - PLoS ONE (2015)

Saccade gain in the double-step task.Vertical and horizontal endpoints of first and second saccades in the double-step tasks.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4549245&req=5

pone.0134483.g003: Saccade gain in the double-step task.Vertical and horizontal endpoints of first and second saccades in the double-step tasks.
Mentions: Saccade gain (saccade amplitude / target eccentricity) was more accurate in the visually-guided task than in the memory-guided task, both for first saccades (0.95±0.15° versus 0.87±0.20°, respectively) and second saccades (0.97±0.17° versus 0.78±0.17°, respectively). The overall difference between visually- and memory-guided tasks was significant (F(1,40) = 21.6, p<0.001). In the visually-guided task, first and second saccade gains were comparable, whereas in the memory-guided task, second saccade gain was smaller than first saccade gain (F(1,40) = 12.2, p<0.001). Fig 3 depicts the saccade endpoints for both conditions.

Bottom Line: Predicting the sensory consequences of saccadic eye movements likely plays a crucial role in planning sequences of saccades and in maintaining visual stability despite saccade-caused retinal displacements.The double-step task measured predictive activity in motor control, and the in-flight displacement task measured predictive activity in trans-saccadic visual perception.We also propose that this difference in results between the perceptual and the motor tasks may point to a dissociation between corollary discharge for perception and corollary discharge for action.

View Article: PubMed Central - PubMed

Affiliation: Laboratoire Psychologie de la Perception, Université Paris Descartes & CNRS, Paris, France.

ABSTRACT
Predicting the sensory consequences of saccadic eye movements likely plays a crucial role in planning sequences of saccades and in maintaining visual stability despite saccade-caused retinal displacements. Deficits in predictive activity, such as that afforded by a corollary discharge signal, have been reported in patients with schizophrenia, and may lead to the emergence of positive symptoms, in particular delusions of control and auditory hallucinations. We examined whether a measure of delusional thinking in the general, non-clinical population correlated with measures of predictive activity in two oculomotor tasks. The double-step task measured predictive activity in motor control, and the in-flight displacement task measured predictive activity in trans-saccadic visual perception. Forty-one healthy adults performed both tasks and completed a questionnaire to assess delusional thinking. The quantitative measure of predictive activity we obtained correlated with the tendency towards delusional ideation, but only for the motor task, and not the perceptual task: Individuals with higher levels of delusional thinking showed less self-movement information use in the motor task. Variation of the degree of self-generated movement knowledge as a function of the prevalence of delusional ideation in the normal population strongly supports the idea that corollary discharge deficits measured in schizophrenic patients in previous researches are not due to neuroleptic medication. We also propose that this difference in results between the perceptual and the motor tasks may point to a dissociation between corollary discharge for perception and corollary discharge for action.

No MeSH data available.


Related in: MedlinePlus