Humans can perform short-term actions while remaining aware of longer-term goals. Evidence suggests that prefrontal areas coordinate motor activity when such goals are being aimed at. The more that abstract rules are involved, the more there is a combination of theta (4-8 Hz) and high gamma (80-150 Hz) phase together with inter-regional information encoding in the frontal cortex.
Archive for the ‘Free Will’ Category
A sub-population of the striatal direct-pathway neurons, known for being connected to voluntary movement, can be the basis of opiate-reward driven activities. The brain’s opioid system is basic to the reward value of stimuli and consequent behaviours. Opioid receptors bind to the brain’s opioid peptides such as enkephalin, β-endorphin, or dynorphin. μ-opioid receptors act to suppress the neuronal activity of neurons that otherwise…
The brain is viewed as having two systems for making decisions. The first approach is to value actions according to the rewards they have generated in the past. A second or model-based approach uses more flexible evaluation of new or changing options, or works on generalisation from known
This study shows that human decision-makers adapt their level of persistence in waiting for rewards to the environment in which the decision is being made. Neural signalling in the ventromedial prefrontal, an area involved with evaluation, could evolve differently for identical time delays, if there is a difference in the environment. The neural valuation system is here seen as including the ventromedial prefrontal (VMPFC), the ventral striatum (VS) and the posterior cingulate cortex
The choices of other people are argued to increase the value of such choices for individuals. The related neural processing is encoded in the ventromedial prefrontal cortex, and the signals are predictive of conformity with other people’s preferences.
This paper can be taken as suggesting that a sense of agency is part of the reward system, encouraging repetition or non-repetition of particular actions or behaviours.
The ventromedial prefrontal cortex is the brain region most associated with ratings of the relative value of stimuli. Subjects are seen as assigning subjective values to the potential outcomes of possible actions leading to valuable results.
A source of despair in consciousness studies is the way in which popular science writers continue to plough ahead making pronouncements that are flatly contradicted by the neuroscientific data of recent years. In particular, consciousness students might be forgiven for screaming every time Libet’s veteran 1980s experiment is trundled out. Halligan and Oakley writing in a recent issue of ‘New Scientist’ go down this predictable route. The brain prepares for actions such as reaching out prior to awareness of the intention to reach.
Decoding intention at sensorimotor timescales Matthew Salvaris & Patrick Haggard :: PLOS one, February 11 2014, DOI: 10.137/journal.pone.0085100 :: http://www.plosone.org/ Summary and review of the above paper This paper examines the difference between the neural processing of small motor actions such as pressing a button, when the action follows on an external instruction, and alternatively when it is seen as the free choice of the subject. This follows the Libet tradition of Read more […]
The recent science fiction film, Ex Machina, about the invention of a conscious android takes us straight to the heart of the nature of consciousness. The android, named Ava, has a clear choice, preference and desire to be free from the underground chamber in which she is confined, and also to be free from the direction of her inventor. The inventor, Nathan, asks the other main character, Caleb, to go beyond the Turing test. This is good advice as the Turing test was an annoying distraction Read more […]