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Paraphrasing Dobzhansky: nothing in the brain makes sense except in the light of behavior. /39

Seeing is not passive reception but active exploration. Held and Hein demonstrated this in kittens: active movement allowed normal development, while passive movement in a gondola prevented sensorimotor coordination. /38

preserve body representations as it grows and changes. Logothetis showed that in binocular rivalry(viewing ambiguous figures) where the visual system alternates between which eye is "dominant", neural activity and eye movements both are essential in determining which image prevails./37

Thalamocortical circuits become controlled by subcortical modulatory system which prevents spindles occurrence during wakefulness. Sleep spindles as you remember follow K-complexes, triggered by spontaneous muscle twitches during sleep. These sleep spindles may adjust somatosensory maps and /36

Brain, body and environment are highly intertwined, creating upward causation of somatic, humoral, autonomic and environmental processes that are as important as the "downward" causation. With myelinization, spindles decrease as the brain "awakens". /35

Similar mechanisms may underlie social communication and speech. Song learning in zebra finches involves "babbling" (similar to babies) and parental reinforcement, not tabula rasa or learning a song syllable by syllable. Each bird starts out with a unique seed syllable /34

The lemniscal pathway carries topographic body representation from spinal cord to thalamus. Lesion in all but lemniscal pathway theoretically should preserve sensations, but rats ignore stimulation below the cut. In humans that thumb-sucking preference may may influence handedness. /33

Putting a cast on the rodents leg for their first 3 weeks (rodents start walking on the 15th day) resulted in long lasting but not irreversible walking abnormalities. To note cast does did not prevent muscle twitches. /32

Paralysis during the second week in rodents severely reduces and disorganizes whisker representations even though they can still be used using head and body muscles. Touch still triggers thalamic responses but their directional organization is missing. /31

Poor myelinization and long-lasting post-activity responses (outlasting stimulus by hundreds of ms) facilitate connection formation, particularly important for spinal pathways and organizing sensory consequences of action. Movement is essential: space does not make sense for immobile observer. /30

Movements activate skin receptors and muscles simultaneously, creating a temporal window for the brain to associate muscles. With several hundred muscles most of the movement combinations are physically restricted by bones and tendons. Spindles help link movements to muscles to body parts. /29

Mechanical stimulation also results in spindles. Surprisingly, this spindle activity outlasts stimuli by several hundreds ms. In experiments with severed spinal cord these spindles can also occur sponatneously like the mu rhythm, but they occur at a lower incidence rate. /28

Rats are altricial (born blind and deaf), similar to human third-trimester development. Neonatal movements, generated by the spinal cord, trigger virtually all spindles. Interestingly baby`s movement activity in the third trimester is a good predictor postnatal feedback indices. /27

These spindles are a result of coordinated activity in corticothalamic and local inputs. Unlike actual sleep spindles these remained local. During the first days cortical layers 2 and 3 has local short dendrites, but layer 5 has mature thalamocortical wiring, so neocortex on is like a mosaic. /26

somatotopic cortical maps, long-range cortical connections, and enhanced experience-dependent plasticity. In contrast to adult activity, neonatal rat brains display sharp bursting activity at ~10 Hz—spindle-like but localized. Initially, brain wiring is exclusively local with poor myelinization. /25

Without action, sensory activity alone cannot generate a useful brain. The first self-generated rhythms are modified by spinal cord inputs. Neurons in isolated newborn rat cortex display giant depolarizing potentials from spontaneous network excitation. By the first week, rats already establish/24

Without the motor system we cant verify distances. Every part of the visual system has spontaneous activity even in darkness, but inputs modify these circuits. Neurons firing together wire into functional groups. Experience accumulates knowledge that drives action. /23

If brain and body were created separately and merged the organism would only have general startle responses like premature babies. Frankenstein would probably not be viable for this same reason. Perceiving is tightly connected to the body. Without skin sensation well never know where our noses at/22

MRI shows faces and 3D objects fail to activate his inferotemporal cortex. However, motion-activated areas show activity, possibly because motion perception isn't unique to vision. No EEG data exists from recovered-blindness patients. /21

But what happens when the blind person regains vision? Mike May, after 5 years of training, can detect color and light intensity but still cannot recognize objects as three-dimensional or navigate without aids. /20

In congenitally blind, occipital alpha is reduced but alpha may become enhanced at anterior brain sites, suggesting thalamocortical rhythms are site-specific and governed by sensory inputs. The occipital cortex acquires new specialized characteristics, so eye movements dont impact occipital alpha/19

After 1-2 weeks of training, some subjects could move cursors with high accuracy in 2-5 seconds. Most striking was the ability to reduce large amounts of neural activity through visual feedback. If sensory input absence drives alpha activity one would assume blindness causes prominent alpha. /18

it's also about enhanced attention and visual imagination. Some yogis can maintain complex mental imagery for hours yet shift their attention rapidly. The ability to shift brain rhythms was thought applicable for controlling remotes, cursors, and objects with the help of EEG headsets. /17

learn to enhance their alpha waves within days, achieving results comparable to years of meditation. However, these were small studies, and commercialization preceded rigorous research, leading to overpromising and the alpha movement's collapse by 70s. And meditation is not simply relaxation, /16

Do these changes require spiritual activity and how do these changes affect behaviour? Some researchers believed enhanced alpha rhythms induce calm and improve cognitive and memory performance. Through neurofeedback(converting EEG patterns into audio tones or visual flashes) subjects could/15

In Zen, alpha oscillations are continuously blocked without habituation. Both types show increase of alpha oscillations. Beginners show increase of alpha in the occipital lobe, intermediates - extended cortical alpha at lower frequency, and advanced practitioners - large theta across the scalp. /14

How would something like that influence sleep and oscillations? Meditation has two types: Yoga (eyes closed, inner focus) and Zen (eyes half-open, object focus). In Yoga, when self and environment disappear, external stimulation no longer disturbs alpha oscillations. /13

These experiments show that sleep rhythms provide a clear regional indicator of sensory experience. Maybe those are triggered by synaptic reorganization? MRI studies show brain areas enlarge with increased activity, like in people who picked up juggling for 3 months. /12

This delta reduction was confined to visual cortical areas, but reversed to normal after 2 months of light exposure to normal light. Stryker showed asymmetric light exposure (one eye closed) in kittens causing growth of plasticity(double), ocular dominance during sleep and nonREM sleep duration./11