Neuroscience
Scientists at the Institute of Neurology have shown that reaching movements with the foot can be controlled by the same kind of rapid, sub-conscious processing as the hand.
Participants were asked to lift and place one of their feet as quickly as possible onto a target located 16cm in front of them. On a quarter of 96 trials, the target jumped unexpectedly 21cm to the left or right. Imagine reaching your foot out onto a stepping stone that suddenly moved. Raymond Reynolds and Brian Day found that in response, participants were able to adjust their reaching movement incredibly quickly - within 120ms - that's just an eighth of a second. The incredible speed of this adjustment suggests the existence of a sub-cortical visuomotor pathway for control of the foot (i.e. one not involving the cerebral cortex, which is associated with conscious thought).
Moreover, when they repeated the experiment without participants being able to grasp hand-rails for balance, they found the same rapid adjustments were made and, surprising the researchers, nobody fell over.
"Normally, foot-placement is pre-planned at the beginning of a step, and tightly coupled to the throw of the body that occurs before foot-off", the scientists explained. "But our results show some mid-swing alteration in foot placement can occur without balance being compromised...the central nervous system can alter foot trajectory quickly while simultaneously ensuring balance is not threatened".
The authors said such control systems could aid walking over uneven terrain, or even a football player's rapid interception of the ball.
_________________________________
Reynolds, R.F. & Day, B.L. (2005). Rapid visuo-motor processes drive the leg regardless of balance contraints. Current Biology, 15, R48-R49.
Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.
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Neuroscience
The foot is also quicker than the eye
Scientists at the Institute of Neurology have shown that reaching movements with the foot can be controlled by the same kind of rapid, sub-conscious processing as the hand.
Participants were asked to lift and place one of their feet as quickly as possible onto a target located 16cm in front of them. On a quarter of 96 trials, the target jumped unexpectedly 21cm to the left or right. Imagine reaching your foot out onto a stepping stone that suddenly moved. Raymond Reynolds and Brian Day found that in response, participants were able to adjust their reaching movement incredibly quickly - within 120ms - that's just an eighth of a second. The incredible speed of this adjustment suggests the existence of a sub-cortical visuomotor pathway for control of the foot (i.e. one not involving the cerebral cortex, which is associated with conscious thought).
Moreover, when they repeated the experiment without participants being able to grasp hand-rails for balance, they found the same rapid adjustments were made and, surprising the researchers, nobody fell over.
"Normally, foot-placement is pre-planned at the beginning of a step, and tightly coupled to the throw of the body that occurs before foot-off", the scientists explained. "But our results show some mid-swing alteration in foot placement can occur without balance being compromised...the central nervous system can alter foot trajectory quickly while simultaneously ensuring balance is not threatened".
The authors said such control systems could aid walking over uneven terrain, or even a football player's rapid interception of the ball.
_________________________________
Reynolds, R.F. & Day, B.L. (2005). Rapid visuo-motor processes drive the leg regardless of balance contraints. Current Biology, 15, R48-R49.
Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.
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Last year the psychologists Steven Tipper and Patric Bach asked students to perform an identification task with a difference. Two men were shown either kicking a ball or typing at a keyboard. Crucially, the students had to signal their recognition of...
- 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...
- 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...
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When we watch someone else being pricked by a needle in their hand, the corticospinal motor neurons connected to that specific part of our own hand are inhibited, just as they would be if we’d been injected ourselves. It’s as though our brain has...
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