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Emotion and consciousness: Ends of a continuum

Alexandrov et al.

Cognitive Brain Research
Volume 25, Issue 2 , October 2005, Pages 387-405

We suggest a united concept of consciousness and emotion, based on the
systemic cognitive neuroscience perspective regarding organisms as
active and goal-directed. We criticize the idea that consciousness and
emotion are psychological phenomena having quite different
neurophysiological mechanisms. We argue that both characterize a unified
systemic organization of behavior, but at different levels. All systems
act to achieve intended behavioral results in interaction with their
environment. Differentiation of this interaction increases during
individual development. Any behavioral act is a simultaneous realization
of systems ranking from the least to the most differentiated. We argue
that consciousness and emotion are dynamic systemic characteristics that
are prominent at the most and least differentiated systemic levels,
correspondingly. These levels are created during development. Our theory
is based on both theoretical and empirical research and provides a solid
framework for experimental work.

ScienceDirect
http://tinyurl.com/77w5b

The mind's mirror

A new type of neuron--called a mirror neuron--could help explain how we learn through mimicry and why we empathize with others.

BY LEA WINERMAN
Monitor Staff
Print version: page 48

You're walking through a park when out of nowhere, the man in front of you gets smacked by an errant Frisbee. Automatically, you recoil in sympathy. Or you're watching a race, and you feel your own heart racing with excitement as the runners vie to cross the finish line first. Or you see a woman sniff some unfamiliar food and wrinkle her nose in disgust. Suddenly, your own stomach turns at the thought of the meal.

For years, such experiences have puzzled psychologists, neuroscientists and philosophers, who've wondered why we react at such a gut level to other people's actions. How do we understand, so immediately and instinctively, their thoughts, feelings and intentions?

Now, some researchers believe that a recent discovery called mirror neurons might provide a neuroscience-based answer to those questions. Mirror neurons are a type of brain cell that respond equally when we perform an action and when we witness someone else perform the same action. They were first discovered in the early 1990s, when a team of Italian researchers found individual neurons in the brains of macaque monkeys that fired both when the monkeys grabbed an object and also when the monkeys watched another primate grab the same object.

Neuroscientist Giacomo Rizzolatti, MD, who with his colleagues at the University of Parma first identified mirror neurons, says that the neurons could help explain how and why we "read" other people's minds and feel empathy for them. If watching an action and performing that action can activate the same parts of the brain in monkeys--down to a single neuron--then it makes sense that watching an action and performing an action could also elicit the same feelings in people.

The concept might be simple, but its implications are far-reaching. Over the past decade, more research has suggested that mirror neurons might help explain not only empathy, but also autism (see page 52) and even the evolution of language (see page 54).

In fact, psychologist V.S. Ramachandran, PhD, has called the discovery of mirror neurons one of the "single most important unpublicized stories of the decade."

But that story is just at its beginning. Researchers haven't yet been able to prove that humans have individual mirror neurons like monkeys, although they have shown that humans have a more general mirror system. And researchers are just beginning to branch out from the motor cortex to try to figure out where else in the brain these neurons might reside.

在这篇文章中提到的mirror neuron的功能很奇特，它与版主文章中的那些神经元一样，也是自主fire，虽然有时它们的努力能否进入意识层面是不一定的，可是就像作者所言：

"This neural mechanism （mirror neuron）is involuntary and automatic," he says--with it we don't have to think about what other people are doing or feeling, we simply know.

Really right?

哪位翻译一下？这样大家讨论起来可以有更多的共同认识。

Your Brain Cells May "Know" More than You Let on by Your Behavior

Newswise - We often make unwise choices although we should know better. Thunderstorm clouds ominously darken the horizon. We nonetheless go out without an umbrella because we are distracted and forget. But do we? Neurobiologists at the Salk Institute for Biological Studies carried out experiments that prove for the first time that the brain remembers, even if we don't and the umbrella stays behind. They report their findings in the Oct. 20th issue of Neuron.

"For the first time, we can a look at the brain activity of a rhesus monkey and infer what the animal knows," says lead investigator Thomas D. Albright, director of the Vision Center Laboratory.

First author Adam Messinger, a former graduate student in Albright's lab and now a post-doctoral researcher at the National Institute of Mental Health in Bethesda, Md. compares it to subliminal knowledge. It is there, even if doesn't enter our consciousness.

"You know you've met the wife of your work colleague but you can't recall her face," he gives as an example.

Human memory relies mostly on association; when we try to retrieve information, one thing reminds us of another, which reminds us of yet another, and so on. Naturally, neurobiologists are putting a lot of effort into trying to understand how associative memory works.

One way to study associative memory is to train rhesus monkeys to remember arbitrary pairs of symbols. After being shown the first symbol (i.e. dark clouds) they are presented with two symbols, from which they have to pick the one that has been associated with the initial cue (i.e. umbrella). The reward is a sip of their favorite fruit juice.

"We want the monkeys to behave perfectly on these tests, but one of them made a lot of errors," recalls Albright. "We wondered what happened in the brain when the monkeys made the wrong choice, although they had apparently learned the right pairing of the symbols."

So, while the monkeys tried to remember the associations and made their error-prone choices, the scientists observed signals from the nerve cells in a special area of the brain called the "inferior temporal cortex" (ITC). This area is known to be critical for visual pattern recognition and for storage of this type of memory.

When Albright and his team analyzed the activity patterns of brain cells in the ITC, they could trace about a quarter of the activity to the monkey's behavioral choice. But more than 50 percent of active nerve cells belonged to a novel class of nerve cells or neurons, which the researchers believe represents the memory of the correct pairing of cue and associated symbol. Surprisingly, these brain cells kept firing even when the monkeys picked the wrong symbol.

"In this sense, the cells 'knew' more than the monkeys let on in their behavior," says Albright.

And although behavioral performance is generally accepted to reliably reflect knowledge, in fact, behavior is heavily influenced - in the laboratory and in the real world - by other factors, such as motivation, attention and environmental distractions.

"Thus behavior may vary, but knowledge endures," concluded Albright, Messinger and their co-authors in their Neuron paper. The other co-authors are Larry R. Squire, a professor in the Department of Psychiatry at the UCSD School of Medicine, and Stuart M. Zola, director of the Yerkes National Primate Research Center in Atlanta.

The Salk Institute for Biological Studies in La Jolla, California, is an independent nonprofit organization dedicated to fundamental discoveries in the life sciences, the improvement of human health and the training of future generations of researchers. Jonas Salk, M.D., whose polio vaccine all but eradicated the crippling disease poliomyelitis in 1955, opened the Institute in 1965 with a gift of land from the City of San Diego and the financial support of the March of Dimes.

Full Text at NewsWise
http://www.newswise.com/articles/view/515337/

Posted by
Robert Karl Stonjek (Thanks Gene Johnson)

［此帖子已被 bioguider 在 2005-10-20 16:49:06 编辑过］

Nature 437, 1158-1161 (20 October 2005) | doi: 10.1038/nature04053
Activity of striatal neurons reflects dynamic encoding and recoding of procedural memories
Terra D. Barnes, Yasuo Kubota, Dan Hu, Dezhe Z. Jin and Ann M. Graybiel

Learning to perform a behavioural procedure as a well-ingrained habit requires extensive repetition of the behavioural sequence, and learning not to perform such behaviours is notoriously difficult. Yet regaining a habit can occur quickly, with even one or a few exposures to cues previously triggering the behaviour. To identify neural mechanisms that might underlie such learning dynamics, we made long-term recordings from multiple neurons in the sensorimotor striatum, a basal ganglia structure implicated in habit formation, in rats successively trained on a reward-based procedural task, given extinction training and then given reacquisition training. The spike activity of striatal output neurons, nodal points in cortico-basal ganglia circuits, changed markedly across multiple dimensions during each of these phases of learning. First, new patterns of task-related ensemble firing successively formed, reversed and then re-emerged. Second, task-irrelevant firing was suppressed, then rebounded, and then was suppressed again. These changing spike activity patterns were highly correlated with changes in behavioural performance. We propose that these changes in task representation in cortico-basal ganglia circuits represent neural equivalents of the explore-exploit behaviour characteristic of habit learning.

Abstract and full text links at Nature
http://www.nature.com/nature/journal/v437/n7062/abs/nature04053.html

Posted by
Robert Karl Stonjek

［此帖子已被 bioguider 在 2005-10-20 16:39:23 编辑过］

试了半天，还是没法在每行最后显示连续的单词，虽然预览没问题

http://www.newscientist.com/channel/being-human/dn8279.html

Women get a bigger buzz from cartoons

Women get more of a buzz out of cartoons, a brain-imaging study has found,
with their brains feeling more rewarded by a funny joke than those of men.

Women and men are often perceived as having differences in their senses of
humour but, until now, there had been no neurological evidence for such
suspicions. The new brain scanning study showed that although men and women
tended to agree on which of the single-panel cartoons they were shown were
funny, they processed the humour differently in their brains.

In particular, women appear to have a lower expectation that the cartoon
will be funny than men. "Women appear to have less expectation of a reward,
which in this case was the punch line of the cartoon. So when they got to
the joke's punch line, they were more pleased about it," says Allan Reiss,
one of the study's authors, at Stanford University School of Medicine in
California, US.

The group of 10 women and 10 men were shown a series of black and white
cartoons. They rated the cartoons for funniness while functional magnetic
resonance imaging (fMRI) identified the active areas of their brains. The
level of activity in those areas was measured using a technique that
analyses the level of oxygenation in the blood.

© Copyright Reed Business Information Ltd
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机器人能识别镜子中的自己？

Dec. 21, 2005- A new robot can recognize the difference between a mirror image of itself and another robot that looks just like it.

This so-called mirror image cognition is based on artificial nerve cell groups built into the robot's computer brain that give it the ability to recognize itself and acknowledge others.

The ground-breaking technology could eventually lead to robots able to express emotions.

Under development by Junichi Takeno and a team of researchers at Meiji University in Japan, the robot represents a big step toward developing self-aware robots and in understanding and modeling human self-consciousness.

"In humans, consciousness is basically a state in which the behavior of the self and another is understood," said Takeno.

Humans learn behavior during cognition and conversely learn to think while behaving, said Takeno.

To mimic this dynamic, a robot needs a common area in its neural network that is able to process information on both cognition and behavior.

Takeno and his colleagues built the robot with blue, red or green LEDs connected to artificial neurons in the region that light up when different information is being processed, based on the robot's behavior.

"The innovative part is the independent nodes in the hierarchical levels that can be linked and activated," said Thomas Bock of the Technical University of Munich in Germany.

For example, two red diodes illuminate when the robot is performing behavior it considers its own, two green bulbs light up when the robot acknowledges behavior being performed by the other.

One blue LED flashes when the robot is both recognizing behavior in another robot and imitating it.

Imitation, said Takeno, is an act that requires both seeing a behavior in another and instantly transferring it to oneself and is the best evidence of consciousness.

In one experiment, a robot representing the "self" was paired with an identical robot representing the "other."

When the self robot moved forward, stopped or backed up, the other robot did the same. The pattern of neurons firing and the subsequent flashes of blue light indicated that the self robot understood that the other robot was imitating its behavior.

In another experiment, the researchers placed the self robot in front of a mirror.

In this case, the self robot and the reflection (something it could interpret as another robot) moved forward and back at the same time. Although the blue lights fired, they did so less frequently than in other experiments.

In fact, 70 percent of the time, the robot understood that the mirror image was itself. Takeno's goal is to reach 100 percent in the coming year.

Full Text from Discovery News
http://dsc.discovery.com/news/briefs/20051219/awarerobot_tec_print.html