Hack #102 : Alter Input With Expectations

This is a hack which never made it into the book, but we thought it worth sharing. At this point, to get the most out of this hack, look at this figure (in a pop-up window) quickly before reading on. It’s not important to try and work out what it is, but have a good look. Seen it? Now, without further ado…

Hack #102: Alter Input With Expectation

feedback_thumb.png

The balance between feed-forward and feed-back connections in the brain gives a clue to the balance between raw sensation and expectations in constructing experience.

Feedback is ubiquitous in the brain. The brain is not just massively parallel [Hack #52], it is also massively interconnected- an awesomely complex cybernetic system.

Continue reading “Hack #102 : Alter Input With Expectations”

Ghosts in the machine

Controversy has erupted over Michael Persinger’s findings that applying weak complex magnetic fields over the temporal lobes can induce unusual experiences, particularly the experience ‘sensing a presence’ in the room, which Persinger has linked to religious belief and spiritual experience.

This work was part of a larger project in which Persinger and his colleagues have reported strong links between temporal lobe disturbance and anomalous beliefs and experiences throughout the population.

However, a group of Swedish neuroscientists led by Pehr Granqvist have reported that they’ve failed to replicate Persinger’s results with magnetic stimulation when they used a double blind approach to running their experiments (where neither the experimentor nor the participant knows whether they are getting magnetic stimulation).

Persinger has replied by stating that the Swedish study was not an accurate replication.

Link to story on nature.com

Online neuroscience tutorial

The second part of a three part neuroscience tutorial has just been published on kuro5hin.org. While the first part covered the basic physiology of the neuron and how signals are generated and propogate within them, the second part deals with how signals are passed between neurons, over the synapse.

The synapse is the principal part of the neuron where neurotransmitters are released. Because of this, it is where most psychoactive drugs have their effect, which often work by mimicking or altering the normal function of neurotransmitters as they communicate signals throughout the brain and other parts of the nervous system.

Left-handers survive best in violent societies

A study investigating the number of left-handed people in tribal societies has found that the more violent the society, the higher the number of left-handers in the population. The researchers speculate that this is due to left-handers having an advantage in hand-to-hand combat, as shown by the higher number of left-handed champions in sports like boxing and fencing.

Some researchers have linked left-handedness to neurobiological stress during the early stages of brain development, so it has been a puzzle why left-handedness remains a common trait in the population, when this sort of biological stress has been linked to other, less advantageous traits, such as higher rates of nervous system and immune system disorders.

The advantage in combat may be one way (among, potentially, many others, including better non-verbal intelligence) in which left-handers have an edge on their right-handed peers.

Link to story on nature.com

Rrrrroar

dinosaur.png “So, I’m not really comfortable with the fact that my mind is actually something physical.” — at Daily Dinosaur Comics [via introvert.net]. Hey that freaks me out too, knowing that the thought “that freaks me out,” is not just accompanied by but actually is some kind of arrangement of the actual physical stuff in my head, which represents (in this context) “that freaks me out.”

There’s a lot to say here, on the philosophical aspects, but I refuse to be drawn into discussion on the nature of representation, emergence, and where “self” is stored by a cartoon T. Rex stomping on a house. Forgive me.