[Marxism] Human Origins

Les Schaffer schaffer at optonline.net
Mon Aug 1 11:55:23 MDT 2005


Charles Brown wrote:

>CB: On this issue of Chimps reading and following maps, this is actually
>more imitative thinking than symbolic.  We discussed this with the late Jim
>Blaut here. Andy may have been in that discussion.
>
>A map "imitates" ,in miniature, the area it represents. 
>


there was an article in Nature magazine last week on "animal-like" 
learning in humans. the authors of the paper were curious to see if we 
homo sapiens had retained our habit-memory learning or whether we 
jettisoned it as symbol-like learning came into the fore.  here is an 
introductory article and the abstract of the paper.

les schaffer

----------------
News

Published in Nature online: 27 July 2005; | doi:10.1038/news050725-6


Humans learn without explicit thought

by Michael Hopkin


Amnesiacs show how we pick up new tricks from force of habit.


Most people remember the act of learning as well as the new skill or 
knowledge itself.

Humans can learn skills without remembering what they have done, 
according to a study of patients with severe amnesia. Such learning is 
seen in monkeys, but experts were unsure whether humans retained this 
ability, because of our tendency to think consciously about whatever we 
are learning.

Most people gather information and abilities through a process of 
'declarative' learning, in which they remember the act of learning as 
well as the new skill or knowledge itself. Hopefully, you'll recall 
reading this article, as well as remembering the nuggets of information 
it contains.

This process of explicit thought offers a fast route to learning, but 
requires sophisticated mental machinery. Declarative learning is centred 
on a brain region called the medial temporal lobe, which is thought to 
coordinate the storage of memories in the brain.

Trial and error

Other animals, which lack our cognitive powers, use a slower, more 
primitive method called habit learning. If one item in a pair of objects 
is designated the 'correct' item, monkeys can learn to select this 
particular item by simple trial and error. Without realizing they are 
doing it, they gradually acquire the habit of picking the right option.

Neuroscientists had been unsure whether humans share this primitive 
ability, or whether our capacity for conscious learning has rendered it 
obsolete. To find out, researchers at the University of California, San 
Diego, gave the task of identifying the correct items in eight pairs to 
patients with severe damage to their medial temporal lobe.

Healthy humans can master the task in no time, because of declarative 
learning. The study's two volunteers, both of whom had permanent amnesia 
as a result of encephalitis, did not remember the objects or the task at 
the start of each session. But they were still able to master the task, 
albeit over several weeks.

How'd I do that?

Despite ultimately achieving success rates of 85% and 92.5%, the two 
patients could not explain why they thought a given item was the correct 
one to choose, says Larry Squire, who led the study. "The patients were 
surprised," he recalls, "and one asked 'How am I doing this?'"

To prove that the subjects had learned the task purely by rote, the 
researchers gave them all of the objects together and asked them to sort 
them into 'correct' and 'incorrect' groupings. They were unable to do 
this, despite having mastered the task when presented with the items in 
pairs, the team reports in Nature1.

The fact that humans can learn in the absence of conscious memory is a 
surprise, says Squire. "We thought it unlikely that such successful 
habit learning would be revealed, because we expected that performance 
would be dominated by efforts to engage in declarative memory," he says.

The exact function of habit learning in humans remains unclear. But 
Squire is now convinced that it has a fundamental role in shaping 
healthy minds as well as those of amnesiacs. "Here arise our 
preferences, dispositions, skills and myriad ways of interacting with 
the world," he says.


===================

Nature 436, 550-553 (28 July 2005) | doi: 10.1038/nature03857


Robust habit learning in the absence of awareness and independent of the 
medial temporal lobe


Peter J. Bayley, Jennifer C. Frascino and Larry R. Squire


Habit memory is thought to involve slowly acquired associations between 
stimuli and responses and to depend on the basal ganglia[1]. Habit 
memory has been well studied in experimental animals but is poorly 
understood in humans because of their strong tendency to acquire 
information as conscious (declarative) knowledge. Here we show that 
humans have a robust capacity for gradual trial-and-error learning that 
operates outside awareness for what is learned and independently of the 
medial temporal lobe. We tested two patients with large medial temporal 
lobe lesions and no capacity for declarative memory. Both patients 
gradually acquired a standard eight-pair object discrimination task over 
many weeks but at the start of each session could not describe the task, 
the instructions or the objects. The acquired knowledge was rigidly 
organized, and performance collapsed when the task format was altered.






More information about the Marxism mailing list