Unformatted text preview: l and frontal lobes jointly develop,
monitor and refine the motor commands for intentional action. 3 Intention
Intention arises as a direct consequence of pre-movement brain
activity in the frontal and parietal motor areas.
The supplementary motor area is a particularly important site for
Fried et al. J. Neurosci. 1991, 11, 3656-66 Intention The motor commmand on its own can produce the hallucination of
When volunteers with an anaesthetised arm are asked to move their
they report the sense of movement.
⇒ The brain only has to send a command to a limb (intention)
to create the sense of movement (i.e. a hallucination of movement) When the SMA is stimulated, subjects report the sensation of an urge to move their
More intense stimulation at the same locations provokes physical movements of the
corresponding limb. Intention A pre-motor stimulation (SMA) can produce the sensation of an
urge to move the limbs.
J. Neurosci. 1991, 11, 3656–3666. The motor commmand on its own can produce the sense of
J Physiology, 2006, 571, 703-10 J. Physiology, 2006, 571:703-10 Hierarchy of action
- Non-intentional: (reflexive)
the lower system produces an action not set by the higher
- Intentional: higher system sets up the lower system.
Intention: translates goals and desires into behavior.
- absent-minded intentional action: (autonomous, automatic)
action runs unmonitored. Action is appropriate to stimulus if
appropriate conditions are met.
- fully executive-controlled intentional action: (voluntary)
higher system plans, triggers and monitors execution of action,
overriding when necessary
Adapted from Trends in Cognitive Sciences, 2005,9, No.6 June 4 From Sensation and Perception
through Attention Multimodal Reflexive Automatic Voluntary Non-intentional Intentional, absent minded Intentional, fully controlled
(Crevits, 2007) Attention
CONSCIOUS CONSCIOUS INATTENTION perception may proceed
Approximately 99% of all information entering through the
senses is dropped (Wolfe, 2001)
Factors that influence attention are meaning and emotion The process by which the brain
- actively selects environmental information to pass on to higher
levels of processing
- actively processes internal information (ie. visceral cues or
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- Dorsolateral prefrontal cortex, Parietal lobe, L. Crevits