Neuroscience
Imagine one of your hands having a life of its own, reaching, grabbing and clutching whatever it likes. Such a condition exists, is known as anarchic hand syndrome, and usually develops after brain damage to the front of the brain. One famous sufferer is Dr Strangelove in the eponymous Stanley Kubrick film. Now Al Cheyne and colleagues think they've found a way to simulate this bizarre condition in the lab.
Cheyne's team had 16 participants perform a test of sustained attention. Whenever a number between "1" and "9" appeared on the computer screen, participants had to press the "M" key on the keyboard with their right hand, with one exception. On the rare occasions that the digit "3" appeared, they had to suppress their usual response and instead press the "Z" key with their left hand.
Whenever they made an error on one of these rare switch trials, the participants were asked to say how much they felt in control of the action, and how much they felt their hand was in control.
Errors on switch trials occurred on average about 35 per cent of the time, and led to the odd sensation of knowing that one should be pressing the "Z" key with the left hand, but instead seeing one's right hand go on ahead and press the "M" key.
Crucially, the participants' reports showed that these errors were associated with the sense that their hand was in control more than they were - a phenomenon the researchers dubbed "attention-lapse induced alienation".
Everyday we perform apparently automatic actions, from brushing our teeth to driving to work, and yet they don't lead to this feeling of alien control. Cheyne's team said the key factor leading to the sense of lost control (both in the lab, and in anarchic hand syndrome) is that the errant action(s) continues in direct conflict with a different consciously intended goal. "For alienation to occur, the automatic action must, as it were, be caught in flagrante delicto and continue even as we intend otherwise for us to imbue it with an alien source," they said.
Link to related Digest post: Simulating déjà vu in the lab.
_________________________________
Cheyne, J., Carriere, J., & Smilek, D. (2009). Absent minds and absent agents: Attention-lapse induced alienation of agency Consciousness and Cognition, 18 (2), 481-493 DOI: 10.1016/j.concog.2009.01.005
Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.
- Getting In Touch With Our Shadows
The sight of our own shadows can affect our sense of touch. That's according to Francesco Pavani and Giovanni Galfano who have shown that seeing the shadow of a part of your body automatically directs your tactile attention to that body part. Forty-two...
- We Become More Ambidextrous As We Get Older
We’re unaware of it, but starting in middle-age, our dominant hand gradually loses its superiority, so that we become, in a sense, more ambidextrous as we get older. Tobias Kalisch and colleagues recruited 60 participants who were all strongly right-handed...
- Looking At Wayne Rooney Impairs The Control You Have Over Your Own Feet
No wonder he’s so adept at getting past defenders. According to Patric Bach and Steven Tipper of Bangor University, the mere sight of Wayne Rooney inhibits the control you have over your feet. Apparently, looking at Rooney automatically triggers football-related...
- Forget Stroop, Here's The Snarc
You’ve probably heard of the Stroop effect (if not, see here), now let me introduce you to the SNARC. The Spatial Numerical Association of Response Codes (SNARC) effect is the observation that people are faster to make a judgment about a number if the...
- It Wasn't Me, It Was Someone Else: Agency Error And Alien Hand
A sense of agency is the feeling that you're initiating and controlling your own movements. This can go awry in schizophrenia, when individuals can experience delusions of control (Lafargue & Franck, 2009). In this state, the patient feels as...
Neuroscience
Simulating anarchic hand syndrome in the lab
Imagine one of your hands having a life of its own, reaching, grabbing and clutching whatever it likes. Such a condition exists, is known as anarchic hand syndrome, and usually develops after brain damage to the front of the brain. One famous sufferer is Dr Strangelove in the eponymous Stanley Kubrick film. Now Al Cheyne and colleagues think they've found a way to simulate this bizarre condition in the lab.Cheyne's team had 16 participants perform a test of sustained attention. Whenever a number between "1" and "9" appeared on the computer screen, participants had to press the "M" key on the keyboard with their right hand, with one exception. On the rare occasions that the digit "3" appeared, they had to suppress their usual response and instead press the "Z" key with their left hand.
Whenever they made an error on one of these rare switch trials, the participants were asked to say how much they felt in control of the action, and how much they felt their hand was in control.
Errors on switch trials occurred on average about 35 per cent of the time, and led to the odd sensation of knowing that one should be pressing the "Z" key with the left hand, but instead seeing one's right hand go on ahead and press the "M" key.
Crucially, the participants' reports showed that these errors were associated with the sense that their hand was in control more than they were - a phenomenon the researchers dubbed "attention-lapse induced alienation".
Everyday we perform apparently automatic actions, from brushing our teeth to driving to work, and yet they don't lead to this feeling of alien control. Cheyne's team said the key factor leading to the sense of lost control (both in the lab, and in anarchic hand syndrome) is that the errant action(s) continues in direct conflict with a different consciously intended goal. "For alienation to occur, the automatic action must, as it were, be caught in flagrante delicto and continue even as we intend otherwise for us to imbue it with an alien source," they said.
Link to related Digest post: Simulating déjà vu in the lab.
_________________________________
Cheyne, J., Carriere, J., & Smilek, D. (2009). Absent minds and absent agents: Attention-lapse induced alienation of agency Consciousness and Cognition, 18 (2), 481-493 DOI: 10.1016/j.concog.2009.01.005Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.
- Getting In Touch With Our Shadows
The sight of our own shadows can affect our sense of touch. That's according to Francesco Pavani and Giovanni Galfano who have shown that seeing the shadow of a part of your body automatically directs your tactile attention to that body part. Forty-two...
- We Become More Ambidextrous As We Get Older
We’re unaware of it, but starting in middle-age, our dominant hand gradually loses its superiority, so that we become, in a sense, more ambidextrous as we get older. Tobias Kalisch and colleagues recruited 60 participants who were all strongly right-handed...
- Looking At Wayne Rooney Impairs The Control You Have Over Your Own Feet
No wonder he’s so adept at getting past defenders. According to Patric Bach and Steven Tipper of Bangor University, the mere sight of Wayne Rooney inhibits the control you have over your feet. Apparently, looking at Rooney automatically triggers football-related...
- Forget Stroop, Here's The Snarc
You’ve probably heard of the Stroop effect (if not, see here), now let me introduce you to the SNARC. The Spatial Numerical Association of Response Codes (SNARC) effect is the observation that people are faster to make a judgment about a number if the...
- It Wasn't Me, It Was Someone Else: Agency Error And Alien Hand
A sense of agency is the feeling that you're initiating and controlling your own movements. This can go awry in schizophrenia, when individuals can experience delusions of control (Lafargue & Franck, 2009). In this state, the patient feels as...