1) visual cortex. Neurons in the visual cortex in vision
neurons are neatly arranged in columns sensitive to the orientation of stimuli and the eye stimulated.
Some columns are dependent on the right eye and is sensitive to horizontally oriented stimuli, others are linked all'occhidi left and take steps to vertically oriented stimuli. The columns are further organized in supercolonne, each of which encodes a specific point of the retina all possible orientations and all possible answers monocular and binocular. The set of
supercolonne provides the basis for image reconstruction in its entirety. Thanks to this organization, in fact, the characteristics of the objects identified by the different neurons are integrated into the higher visual centers (eg. The bottom of the temporal lobe). So, if those features from different neurons are part of a face, the temporal cortex reassembles for the sum and integration.
The collection of forms and signs recognized by neurons in the visual cortex as a whole, is a sort of repertoire that draws from the brain to analyze, interpret and reconstruct the images from the outside world (pp. 16-7).
2) The register of deeds.
motoneurons in the behavior of these neurons has begun to see the logic. The same neuron is activated for movements of different muscles, and the right hand, both the left and even the mouth, provided that the purpose motion is the same, on the contrary, two movements are very similar, for example the index finger, activated when a neuron has a specific purpose, but one neuron to another when they differ.
Even the manner in which the hand grasps an object due to activation of different neurons (p. 23). [...] Thus the sensory information coming from objects are intertwined and combined with the capabilities and capacity for action of the macaque, based on a common denominator: the order that the animal wants to achieve. Neurons that have involved both sensory and motor function, two factors cited in the classical conception of cognitive science were instead separate and independent. Those neurons develop pragmatic information that say nothing about the identity or the quality, but the animal interaction and driving him into a position to act (p. 24).
The collection of these neurons is the footage of the brain's motor acts, so called to distinguish them from purposeless movements, which do not activate motor neurons involved in direct actions to objects.
3) Mirror neurons (premotor cortex)
There are neurons that are activated when you do a certain action, is reflected when one observes the same action performed by others.
These neurons act as the motor neurons when activated by its own actions, and show their characteristics when they are activated in response to the same action performed by others. As the cousins \u200b\u200b
engines, also mirror neurons are activated each very specifically for some action. The aim of the others is therefore the key criterion by which these cells can be classified. In analogy with the motor neurons, in neurons-grab, tear and so on. [...]
For the first time, was identified as a neural mechanism that allows to directly merge the visual depiction of a share to its understanding and implementation. Understand in terms of neuronal action means that the brain has the ability, through the activities of its circuits of neurons, to obtain an internal description of an action and use it to plan future motor behavior (pp. 32-3). The activation of mirror neurons is not only transitive actions (direct object) but also for intransitive (no direct object).
► To what extent can push the capacity of abstraction of mirror systems in evoking action?
When we think of action, we read or look at the description, in our brain circuits are activated the same mirror. These circuits seem therefore play a key role in mentally represent actions, is that it should be noted, is that they evoke through sound processing (pp. 44-6).
4) The what and why of an action
► What we need to understand the actions of others? ►
The mirror mechanism has evolved to recognize only the actions of others or has more features?
Mirror neurons do not pick up on the basis of a specific type of stimulus - motor, auditory, visual - but when the animal is able to understand what others are doing regardless of the channel by which they perceive the actions.
But mirror neurons have an additional function. They can in fact to inform the viewer not only the action that one performs, but also because he is doing, that is, about his intentions. In particular, it recognizes the 'others' intention from the outset, ie from the first part of the action. Moreover, this intention from the start organizing all motor acts that compose it.
► How does this happen?
Through a simulation , though unconscious (automatic) inside. That means making an inference to the limit without any form of mental representation, ie by activating neuronal maps only. To sum up, mirror neurons are able to read other people's movements in both the objectives, is the motivation behind it. ►
By what criteria they choose their own movements rather than those others?
The animals usually use a small part of the repertoire of movements available to achieve the same goal, choosing those that are best suited to perform that specific action. Thus, the policy seems to be the presumed intention, codified in chains of neurons, and then moves that are best placed and most likely, according to a given context, to produce a fluid , 's action needed to achieve a particular goal rather than another.
► What happens instead when I look an action that does not belong to my repertoire acquired?
Overall, the data collected so far indicate that primates, human or otherwise, recognize and understand the actions of other neurons through two mechanisms, one that somehow manages to match the observed action with the action to follow, 'other based on reasoning or on higher-order cognitive processes. The first pair may be because the two moments of observation and execution, probably have two "molds" which are very similar, or at least fail to agree upon a common ground: that the meaning of the action.
Note: From this point, we speak only of the human mirror neurons, but so far it was intended to both.
5) The identification human
► How do humans understand the emotions of others.
There are more possible ways.
a) One of these passes through cognitive processing of emotion and logic of others: for example, if we look at a person moved, one can imagine the feeling that this person is trying through rational deduction, but does not make us live the same feeling.
b) Or the emotional state of a person can find a direct correspondence in the observer. In this case, the observer feels the same emotion of the person observed, There is talk of empathy . There is therefore a mechanism that allows us to understand the emotions of others once again living within us. This mecca mechanism is very similar to the one that controls the understanding of actions and intentions, in both cases of a mirror mechanism. We humans are therefore able to feel sensations and emotions of others through a mirror mechanism which is capable of restoring and activating a kind of mold in our emotional brain cortex. The mirror neuron system in human beings has thus proved to be a network of brain mechanisms evolved sophisticated, located in different cortical areas: the recognition of actions and intentions is in the inferior frontal gyrus and inferior parietal lobe , while the identification of the observation face of pain and disgust involve mainly the cortical areas calls anterior insula and rostral cingulate .
► What is fake?
The animals seem to be unable to imitate the limit one can speak of:
a) automatic imitation, a kind of response facilitation . A bird flies, the nearby makes the same movement. The movement of the first animal work, probably only release signal of an action that is useful for example for the survival of flock. But this action is not required to understand the action (how), or of his reason (why).
Even among human beings are abundant examples of imitation automatic and involuntary, which we could classify as facilitation of response. They include, in addition to yawning, laughter, tears and reproduction of involuntary facial expressions.
The fact remains that these cases are different from one another phenomenon that is imitation:
b) the response of a voluntary movement observed. In this case, means to imitate, in fact consciously perform an action after having seen a similar one made by another, a process that involves processing brain more complex than that required by automatic imitation. But we must distinguish two situations.
b1) We can play a note that we already know.
b2) Or we can perform movements that have never done before. Becomes more difficult to imitate. It also means the chance to learn new behaviors.
For students of animal behavior occurs only true imitation in this case.
Wolfgang Prinz noted that, as far as to imitate the action is similar to the model already in use, the more we are quick and precise. According to Prinz and his colleagues in our brains would seem to be a common code visual and motor that turns the immediate visual model of a movement in a motor act. According Rizzolati this replication mechanism of action seen might be attributed to the mechanism of mirror neurons.
► What happens when we perform an action for the first time, imitating someone who teaches us?
We see an example to imitate the agreements made by another on a guitar without knowing how to play.
During this task, the mirror neuron system has been particularly active during the observation gestures of others and during the break before the next, probably used to reprocess the movements to be performed. During the pause has also enabled further area, located in the frontal lobe, which was already known to be responsible for planning functions of movement and memory.
So imitation is likely that difficult in that mirror neurons seem to be involved.
More specifically, if it seems difficult that the images received are processed in the mirror neuron system, which produces an internal motor representation of the action. In particular, the visual representation is decomposed into its elementary components, which are borne out in segments already present in the repertoire of the brain's motor acts. The various segments selected by the mirror system are then assembled in the order required to enable the smooth execution of the harmonica and to learn. This assembly is made that air from the frontal lobe that we have seen active during the break between observation and action, when the student tries to be, internally, the agreement that has seen perform and then repeat. This reconstruction explains only part of the process of learning by imitation, which also involve other brain functions, such as attention, memory. In addition, there must be mechanisms to simultaneously inhibit the execution of the movement observed in these cases, limiting the brain activity in a simulated interior. [Conscious simulation latter process can be approached as running processes as self Damasio].
6) Conclusion
Without mechanisms mirror the world around us may seem incomprehensible as much as a planet populated by aliens, we could probably not have a social life and our survival would not be granted.
7)
Paper "In the minds of others. Mirror neurons and social behavior, "James Rizzolati, Luisa Vozza, Zanichelli, Bologna 2008
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