Resume: A new study sheds light on the phenomenon of “control delusions,” often experienced by schizophrenia patients. This state, characterized by the belief that one’s actions are controlled by external forces, is linked to an altered perception of the time between actions and their results.
The research may pave the way for predicting and improving understanding of this condition.
Key Facts:
- Individuals with “control delusions” perceive the time interval between their actions and consequences differently than those without the disorder.
- The mechanism of ‘intentional binding’ – the perceived temporal closeness between an action and its outcome – does not work in schizophrenia patients who experience control delusions.
- This research could potentially contribute to the prediction and better understanding of the self-disorder in schizophrenia patients.
Source: HELLO H
The feeling that your own actions are controlled by outside forces is a common feature of schizophrenia.
A research team from the Hertie Institute for Clinical Brain Research, the University of Tübingen and the Center for Mental Health at the University Hospitals of Tübingen has now investigated this phenomenon of “control delusion” in more detail.
One study found that people experiencing this delusion perceive the length of the time interval between their own actions and their consequences differently than healthy people. With their new findings, the researchers may be able to predict the likelihood of feelings of control and increase our understanding of this disorder of the self.
This is relevant because concepts such as personal responsibility are embedded in the self and shape large parts of our social lives, up to and including the administration of justice, the researchers explain. The study is published in the current issue of the journal PNAS.
Observed transient connection
“To investigate the sense of action authorship, we focused on the phenomenon of intentional binding,” says joint study leader Dr. Axel Lindner. This term, he says, describes the perceived temporal proximity between an action and its consequence.
Lindner cites the switching on of a lamp as an example: “I flip the switch and at the same time the lamp lights up. The short time sequence helps me understand that it was I who turned on the light.”
However, there are situations where the sequence is not timed so precisely, such as with energy-saving light bulbs, which often only light up after a certain amount of time.
“Here our brains subjectively change the perception of the action and its consequence: turning on the switch is perceived as later and lighting up as sooner than it actually is.” A clever mechanism – but one that doesn’t work in patients with control insanity, as we’ve now discovered,” says Lindner.
In collaboration with Professor Marc Buehner of Cardiff University (UK), the Tübingen team recruited 20 healthy subjects and 20 patients with schizophrenia. Ten of them suffered from feelings of external control.
All subjects performed the same task: they had to indicate when they saw a lamp burning by pressing a button with their right hand.
There were three different experimental conditions: in one the lamp was turned on by a switch with the subject’s left hand. In another, the subjects observed how a machine did the switching on for them. As a control, there were times when the lamp on was announced only by a preceding cue stimulus.
“The most important thing about this experimental setup was that the lamp had a fixed turn-on delay of half a second in all cases,” says the study’s first author, Manuel Roth.
“So the interval between the three supposed triggers and the test lamp going on was always the same length.”
Intentional bonding as a measurable phenomenon
However, the subjects perceived the length of the interval differently. When the subjects were required to press a switch beforehand, both healthy and schizophrenic patients without control insanity clearly showed intentional binding, the researchers report. Subjects signaled that the light came on significantly earlier than it actually did.
They also found that the duration was shorter than if the machine pressed the switch or if only a pre-cue stimulus was given. Here the participants experienced the period until the lamp was lit as longer.
However, in patients with control delusions, the mechanism of intentional binding did not play a role.
They found the time interval to be the same in all three cases. “After having to operate the switch themselves, they even reported that an external force – probably a computer – turned on the lamp.”
Accordingly, the weaker their intentional binding was, the more they perceived their own actions as externally determined in everyday life.
The researchers say this study underscores the importance of an intact perception of temporal closeness between action and consequence for feelings of authorship over actions. The study also adds to our understanding of the diminished sense of agency in schizophrenia patients with control insanity.
The researchers hope that such simple mechanistic explanations can be used in the future to quantitatively assess this disorder of self in schizophrenia and predict the likelihood of its occurrence.
“Our study so far is purely basic research on a small group that cannot provide immediate improvement for patients,” said neurobiologists Roth and Lindner.
“However, the study provides important clues about how they can improve their perception of self-action. Future research will have to show whether this is possible.” The work makes sense of a psychological problem using relatively simple mechanisms, says Lindner:
“This insight alone can help affected patients and improve social acceptance of the disease.”
About this news about schizophrenia research
Author: Cardinal Mary
Source: HELLO H
Contact: Mareike Cardinal – HIH
Image: The image is credited to Neuroscience News
Original research: Closed access.
“Impaired perception of temporal contiguity between action and effect is associated with impairment of agency in schizophrenia” by Manuel J. Roth et al. PNAS
Abstract
Decreased perception of temporal contiguity between action and effect is associated with impairment of agency in schizophrenia
Delusions of control in schizophrenia are characterized by the striking sense that one’s actions are controlled by external forces.
We tested here qualitative predictions inspired by Bayesian causal inference models, suggesting that such misattributions of agency should lead to diminished intentional binding.
Intentional binding refers to the phenomenon that subjects perceive a compression of time between their intentional actions and the ensuing sensory events. We show that patients with control delusions experienced less self-efficacy in our intentional binding task.
This effect was associated with significant reductions in intentional binding compared to healthy controls and patients without delusions. In addition, the strength of delusions of control correlated closely with decreases in intentional binding.
Our study confirmed a critical prediction of Bayesian descriptions of intentional bonding, namely that a pathological reduction of the prior likelihood of a causal relationship between one’s actions and ensuing sensory events—here trapped by delusions of control—should lead to less intentional bonding.
In addition, our study emphasizes the importance of an intact perception of temporal contiguity between actions and their effects on the sense of freedom of choice.