Attention - based on the approximate reflex. Addictive

Attention - based on the approximate reflex. The manifestation of vegetative reactions (GSR, dilated pupil, dilation of cerebral vessels), motor responses (increased muscle tone, involuntary movements), changes in EEG (depression of a-rhythm, increased power in the high-frequency zone - from 30 Hz, r-rhythm). The reason for the orientation reaction is novelty. For this, the brain must have an idea that it is not new, that it constantly surrounds it. And also perform matching operations. The brain has a picture of the world, then a destractor appears, which destroys it, the brain begins to search for what the new picture differs from the usual - an indicative reflex.

The concept of a nervous stimulus model (Sokolov) - the brain continuously forms environmental models, the more stable the environment, the faster the image is formed. The slightest deviation from the usual pattern initiates an indicative reflex. A model is the result of a memory operation. The approximate reflex is the result of a mismatch in the comparison of the new stimulus with the educated model. If the stimulus coincides with the model, then the approximate reflex does not occur. Memory is the result of a lot of brain activity and activity.

Sokolov was the first to say that the brain is engaged in different activities, but the process of perception continuously forms an image in memory (short-term), which does not require any effort. The brain works in different ways - automatically it is engaged in memorizing the surrounding conditions (involuntarily), it is specially engaged in the main activity (arbitrarily). The approximate reflex interrupts the main activity and involuntarily draw attention to something new, changes. Reaction to novelty - hazard assessment - evaluation of interest.

The essence of the concept:

1) the brain forms a model of the environment continuously automatically;

2) every time all perceived stimuli are compared with models; if there is a complete coincidence, then orientation is absent, and if there is no complete coincidence, then an approximate reaction occurs, interrupting the main activity.

Addiction - reflects the process of formation in memory of the nervous model of the stimulus; This is the second side of the model.

The model is multidimensional, it contains information about all the physical characteristics of the stimulus, including spatial and temporal, reflects all the modalities with all their characteristics. The brain reacts even to the slightest change in the stimulus, the environment. Involuntary memory does not have a volume limit, it is a permanent cast of the world. It is multidimensional and has a protective function.

The process of model formation is expressed in the fact that all components of the orientation reaction gradually disappear (the extinction of the orientation reaction, habituation).

Habituation is an example of negative learning , as a result of which orienting reactions previously caused by a stimulus are suppressed. Approximate reactions disappear, if a strong stimulus is repeated constantly or repeatedly, the brain adapts.

The first incentive in the corporator has no matches, because there are no models yet. Further, the model is formed and the repeating stimulus already coincides with it, there are no impulses of mismatch - the approximate reflex dies out (slows down). Then there is a small change in the stimulus - there are disagreement impulses, an approximate reflex is disinhibited.

The most interesting in the process of determining the novelty is the hippocompalial formation, where the neurons of novelty and identity are found.

All neurons of the cortex have 2 types of input - specific and non-specific. Respectively come two kinds of signals. Specific is the signal on which the function of a given neuron is oriented, which causes the neuron to perform its function. Nonspecific - allows you to enhance the reaction coming from the specific.

Neurons of novelty - react to a new (first) stimulus, with repetition there is an addiction and the reaction is fading away. The habituation effect is very selective, the signal identity must be almost complete.

Identity neurons - react to a familiar signal, the reaction appears as you get used to, get to know, the more repetitions of the stimulus, the higher their activity.

On one group there is an accumulation of information, on the other there is a comparison.

Without an indicative reflex memory is not formed. The greater the indicative reflex, the more likely it is that more information will be stored. Therefore, long-term memory also depends on the hippocampus.

An approximate reflex is a complex of body reactions, the basis of involuntary attention. The modulating system of the brain is a non-specific system, and the neuron of this system is a modulatory neuron, through which a non-specific signal is given. It can act (to spread its influence) synaptically (directly on the soma) and presynaptically (on the axons). There are local and generalized modulators.

Conceptual reflex arc of Sokolov.

Detector - command neuron - modulator neuron - motor neuron - effectors. The detector received a signal and transmitted to the command neuron, which is connected with a group of motor neurons, then effectors. The modulator neuron can be triggered by a sensory signal, then it keeps control of both the command neuron and the motor neuron.