1. Higher Functions of the Brain

2. Higher Functions of the Brain
Behavior
Sleep and arousal
Emotions
Memory and Learning
Language
Personality
Movement - Integration

3. Higher Functions of the Brain
Behavior
Sleep and arousal
Emotions
Memory and Learning
Language
Personality

4. Consciousness and its mechanisms
Consciousness is special form of perceiving surroundings and goal- orientated activity of person with interrelation to surroundings.
Only social life forms consciousness.
It involves life experience of entire society.
This ability of prefrontal areas to keep track of many bits of information could well explain abilities to prognosticate, do plan for the future, delay action in response to incoming sensory signals, consider the consequences of motor actions even before they are performed, solve complicated mathematical, legal, or philosophical problems, correlate all avenues of information in diagnosing rare diseases and control our activities in accord with moral laws.

5. Structure of behavioural act
According to theory of functional systems (Anochking) there are such stages of behavioural act:
1) afferent synthesis;
2) taking of decision;
3) acceptor of result of action;
4) efferent synthesis (or programming of action);
5) performing of action;
6) evaluation of final result of action.
Due to converging and processing of both sensory information and memory traces afferent synthesis in the brain is performed. Taking of decision is based on afferent synthesis by choosing optimal variant of action.

6. Behavioral State
Four different systems which appear to modulate sensory and cognitive processes and motor output
Neurons composing them form diffuse modulatory systems
These clumps of neurons form nuclei sending axons which travel toward various areas of the brain
The nuclei are located in reticular formation in brain stem
The 4 processes are:
- the noradrenergic modulatory system
- the serotonergic modulatory system
- the dopaminergic modulatory system
- the cholinergic modulatory system

7. Noradrenergic modulatory system
Role:
sleep-wake cycle,
attention,
arousal,
anxiety,
pain and
mood
Promotes brain responsiveness
Part of the Reticular Activating System (RAS)

8. How to mess up the system?
Drugs that interfere with epinephrine / norepinephrine metabolism will affect this system.
Amphetamine and cocaine block NE reuptake  remain in the synapse longer

9. Serotonergic modulatory system
Role:
- Pain, locomotion
- mood and emotional behavior (aggression and depression)
- Part of the RAS
- modulates sleep

10. How to mess up this system?
Amphetamines: block reuptake
LSD: serotonin agonist – hallucinogen

11. Dopaminergic modulatory system
Roles:
- motor control
- reward center (linked to additive behavior)

12. Dopamine/substantia nigra
Involved in motor control  helps with smoothness of movement, muscle tone
Disease: Parkinson’s disease due to a deficit of dopamine secretion

13. Dopamine/ Ventral tegmental area
Reward pathway
Rates offered choices, will take the drug even if it has deleterious effects on its health

14. How to mess it up? Many drugs affect this pathway:
Physiological dependence:
The drug overwhelms the receptors in the synapse  they are pulled out  more drug is needed for the same effect  if the drug is stop the person suffers withdrawal symptoms
How to mess it up?
Many drugs affect this pathway:
nicotine, cocaine, morphine, heroin
This pathway is down- regulated  withdrawal symptoms develop if the person stops taking the drug.

15. Cholinergic modulatory system
Role:
- Sleep-wake cycle, arousal
- learning and memory
- control sensory info. passing by the thalamus

16. States of Arousal – Sleep cycle
Reticular activating system keeps “conscious brain” awake
Some of the previous modulatory systems are part of the RAS

17. Higher Functions of the Brain
Behavior
Sleep and arousal
Emotions
Memory and Learning
Language
Personality

18. SLEEP
Unconciousness state from which a person can be aroused by sensory or other stimuli;
It’s divided into two entirely different types of sleep that have different quantities & alternate:
slow- wave sleep (NREM) &
rapid eye movement sleep
(REM)

19. ECG stages of sleep
Has multiple stages: from very deep to very light sleep

20. Determined by the level of excitation of sleep, wakefulness or brain diseases (epilepsy and psychosis).
SLEEP & BRAIN WAVES
Measured by
“Electroencephalograp hy (EEG) is the measurement of electrical activity produced by the brain (cortex) as recorded from electrodes placed on the scalp.“

21. SLEEP : SLOW- WAVE SLEEP
In this type of sleep the brain waves are very strong & show a low frequency;
Occurs during the first hour after going to sleep & it’s exceedingly restful;
↓ of peripheral vascular tone & other vegetative functions of the body, such as: a 10 to 30 % ↓ in BP, in respiratory rate & in basal metabolic rate;
Called “dreamless sleep”, although dreams do occur during this phase.
The difference between this and REM sleep is that they’re associated with less bodily muscle activity & also that during this phase the consolidation of dreams in memory doesn’t occur.

22. SLEEP : SLOW- WAVE SLEEP
More restful type of sleep;
Associated with (viscero-)motor activities;
4 Phases:
- I (Drowsiness): low voltage fluctuations, alpha waves reduced;
II (Light sleep): low voltage of delta waves;
III (Medium sleep): frequency of delta waves reduced, amplitude increases;
IV (Deep sleep): delta waves more prominent, low frequency and high altitude.

23. SLEEP : REM ( RAPID EYE MOVEMENT) SLEEP, PARADOXICAL SLEEP, DESYNCHRONIZED SLEEP
Bouts of REM sleep last for 5 to 30 min & usually appear on average every 90 minutes;
As the person becomes more rested during the night, the durations of the REM bouts ↑;
REM characteristics:
Active dreaming & active bodily muscle movements;
The person is more difficult to arouse by sensory stimuli than during the deep slow- wave sleep & people usually awaken spontaneously during a REM episode;
Muscle tone is exceedingly depressed – strong inhibition of the spinal muscle control areas;
Heart rate & respiratory rate become irregular;
Irregular muscle movements occur;
Brain is ↑ active & brain waves are similar to those of wakefulness.

24. 5-30 minutes long, every 90 minutes;
SLEEP : REM ( RAPID EYE MOVEMENT) SLEEP, PARADOXICAL SLEEP, DESYNCHRONIZED SLEEP
5-30 minutes long, every 90 minutes;
↓ muscle tone;
↑ brain metabolism ( as much as 20 % );
Irregular heart and respiratory rate;
Rapid eye movements;
Less restful, desynchronised;
Associated with psychical activities, such as dreaming.

25. BASIC THEORIES OF SLEEP
PASSIVE THEORY OF SLEEP: this earlier theory of sleep said that the RAS became simply fatigued during the day & as a result inactivated during the night;
It was later proved that sleep is caused by an active inhibitory process, once that there seems to be a center located below the midpontile level of the brain stem that is required to cause sleep by inhibiting other parts of the brain;
ONTOGENIC HYPOTHESIS OF REM SLEEP says that the activity occurring during neonatal REM sleep (or active sleep) seems to be particularly important to the developing organism. Deprivation of active sleep early in life was shown to result in behavioral problems, permanent sleep disruption, decreased brain mass.

26. PHYSIOLOGICAL EFFECTS OF SLEEP
Sleep has two major effects: at the level of the nervous system & at the level of other functional systems of the body;
The effects on the CNS are far more important; prolonged wakefulness is associated with progressive malfunction of the thought processes & can cause abnormal behavioural activities;
Sleep, in multiple ways, restores both NORMAL LEVELS OF BRAIN ACTIVITY & NORMAL BALANCE AMONG THE DIFFERENT FUNCTIONS OF THE CNS;
“ The principal value of sleep is to restore the natural balances among the neuronal centers.”

27. Higher Functions of the Brain
Behavior
Sleep and arousal
Emotions - Moods
Memory and Learning
Language
Personality

28. Emotion and Motivation
The link between emotions and physiological functions.
The limbic system controls many emotions.
The amygdala is an important center of fear, anxiety.
Emotions can influence
somatic,
autonomic,
endocrine and
immune responses.

29. Notion “emotions”
Emotions are aspect of higher nervous activity that characterize subjective attitude of person to various stimuli arousal in surroundings.

30. Emotional status reflects actual needs of man and helps in its realization.

31. Nervous structures and emotional reactions
Areas of the brain that play an important role in the production of emotions include the reticular formation, the limbic system, and the cerebral cortex.

32. Classification of emotions
According to subjective status there are positive and negative emotions.
Negative emotions are asthenic (aggression, affect) that stimulate human activity and asthenia (horror, sadness, depression) that inhibit behaviour.
Lower or elementary emotions are caused by organic needs of man or animal as hanger, thirst and survival, so on).
In humans even lover emotions undergo to cortical control and are brining up.
Social, historical and cultural customs cause also formation of higher emotions that regulates public and private relations in society.
Higher emotions appear due to consciousness and may inhibit lower emotions.

33. Appearance of emotions in ontogenesis
In newborns emotions of horror, anger, pleasure, are revealed just after birth.
Hunger, pain, getting cool, wet bedclothes cause in newborn child negative emotions with grimace of suffering and crying.
Sudden new sound or loss equilibrium causes horror and loss of free movement causes anger.
Final formation of human emotions develops gradually with maturation of nervous and endocrine regulatory systems and needs up brining.

34. Biological importance of emotions
Emotions are important element of human behaviour, creation of conditioned reflexes and mentation.
Negative emotions give fusty evaluation of current situation does it useful or not.
Mobilizing of efforts helps then to satisfy current needs of person.
Positive emotions help to put in memory scheme of behaviour, which was useful and have lead to success.

35. External manifestations of emotions
Motor manifestations of emotions are mimic, gesticulation, body posture and walk.
Emotional excitation usually is followed by autonomic reactions as blush, dilation of pupils; increase of arterial pressure, rate of heartbeat and breathing. Level of catecholamines in blood and 17-oxycetosteroides in urine rises also.
Positive emotion may activate parasympathetic division of autonomic nervous system.
Severe emotional excitation may result in visceral disorders because of circulatory disturbances and excess hormones in blood.

36. Theories of emotions
Biological theory of emotions (P.K. Anochkin) considers that life course includes two main stages of behavioural act:
1) formation of needs and motivations that results from negative emotions and
2) satisfaction of needs that leads to positive emotions it case of complete accordance of image and result of action. Incomplete compliance of suspected and real result of action cause negative emotions and continues behavioural act.
Information theory of emotions (P.V. Simonov)considers that emotions reflect strength human of need and possibility of its satisfaction in current moment.
In absence of needs emotions can’t arise.
There is also not emotional excitation, if getting excess information about mode of satisfaction this need.
Low of information already causes negative emotions that help to recall to mind life experience and to gather information about current situation.

37. Neurotransmission of emotional excitation
Emotional excitation is spread in the brain due to variety of neurotransmitters (noradrenalin, acetylcholine, serotonin, dopamine and neuropeptides including opioids.
Positive emotions may be explained by revealing catecholamines and negative emotions, aggression result from production acetylcholine in the brain. Serotonin inhibits both kinds of emotions.
Decrease of serotonin in blood is followed by groundless anxiety and inhibition of noradrenergic transmission results in sadness.

38. Higher Functions of the Brain
Behavior
Sleep and arousal
Emotions
Memory and Learning
Language
Personality

39. Memory and learning Types of memory
Memory is the ability to hold on to or recall a piece of information
Learning is the ability to retain and apply past memories
Types of memory
Short-term memory
Retained for short period like a phone number you look up
Long-term memory
Retained for long period, perhaps for life
Combination of semantic memory (words, numbers) and episodic memory (people, events, etc.)
Skill memory
Combinations of motor activities like swimming, using scissors, etc.

40. Memory as psychical function
Memory function helps fixing of perceived information, keeping it in verbal form or as traces of percept stimuli and recognizing of this information in proper time.
Genetic memory keeps information about body structure and forms of its behavior.
Biological memory is presented in both philogenetic and ontogenetic forms.
The immune memory and psychical memory for instance, belong to ontogenetic memory.
General characteristics of memory are duration, strength of keeping the information and exactness of its recognizing.
In man mechanisms of perception and keeping the information are developed better, comparing to other mammalians.
According to duration is concerned short-time and long-time memory; in relation to kind of information – sensory and logic.

41. Long-term memory circuits
Long-term memory storage and retrieval
Memories are stored in bits and pieces in association areas
Hippocampus pulls these all together to allow us to recall them all as a single event
Amygdala is responsible for emotions associated with some memories

42. Short term – Long term and working memory
Eric Kandel showed initially that weaker stimuli give rise to a form of short term memory, which lasts from minutes to hours.
The mechanism for this "short term memory" is that particular ion channels are affected in such a manner that more calcium ions will enter the nerve terminal.
This leads to an increased amount of transmitter release at the synapse, and thereby to an amplification of the reflex.
This change is due to a phosphorylation of certain ion channel proteins, that is utilizing the molecular mechanism described by Paul Greengard.

43. Short term – Long term and working memory
A more powerful and long lasting stimulus will result in a form of long term memory that can remain for weeks.
The stronger stimulus will give rise to increased levels of the messenger molecule cAMP and thereby protein kinase A.
These signals will reach the cell nucleus and cause a change in a number of proteins in the synapse.
The formation of certain proteins will increase, while others will decrease.
The final result is that the shape of the synapse can increase and thereby create a long lasting increase of synaptic function.

44. Short term – Long term and working memory
In contrast to short term memory, long term memory requires that new proteins are formed.
If this synthesis of new proteins is prevented, the long term memory will be blocked but not the short term memory.
Is associated with structural changes in synapes
increase in # of both transmitter vesicles & release sites for neurotransmitter
increase in # of presynaptic terminals
changes in structures of dendritic spines
increased number of synaptic connections

45. Long term potentiation
Memories are caused by groups of neurons that fire together in the same pattern each time they are activated.
The links between individual neurons, which bind them into a single memory, are formed through a process called long-term potentiation. (LTP)
Ca2+
Mg2+
Na+
Glutamate
Presynaptic
axon
Postsynaptic
cell
Ca2+ entry activates second
messenger pathways.
Glutamate is released.
Ca2+ enters cytoplasm.
Net Na+ entry depolarizes
the postsynaptic cell.
Depolarization ejects Mg2+
and opens channel.
Cell becomes more sensitive
to glutamate.
Paracrine from postsynaptic
cell enhances glutamate
release.
Paracrine
release
NMDA
receptor
AMPA 4 5 1 2 3 6

46. Long-term potentiation (LTP)
An enhanced synaptic response in hippocampus
Important to memory storage
Excitotoxicity-death of postsynaptic neuron most likely from mutation
Glutamate may mediate this
Explains small memory difficulties as we age

47. Learning Learning has two broad types
Associative (2 stimuli are associated  Pavlov’s dog)
Nonassociative
Habituation (decreased response to irrelevant signals but response to significant stimuli)
Sensitization (opposite of habituation: strong response to a repeating stimuli –first exposure was distasteful or scary)

48. Habituation
The sensory neuron, receiving constant stimulation, slows down its response  less neurotransmitter released at the synapse.
Ex: blanking out excess sounds
At the molecular level, the habitation effect in the sensory terminal results from progressive closure of calcium channels through the presynaptic terminal membrane.

49. Sensitization
Stimulating the sensory neuron results in an increased response (release of neurotransmitter)
Ex: Strong fear response to an insect if we have been stung once
In case of facilitation, the molecular mechanism is believed to be following.
Facilitated synapse releases serotonin that activates adenylyl cyclase in postsynaptic cell.
Then cyclic AMP activates proteinkinase that then causes phosphorylation of proteins.
This blocks potassium channels for minutes or even weeks.
Lack of potassium causes prolonged action potential in the presynaptic terminal that leads to activation of calcium pores, allowing tremendous quantities of calcium ions to enter the sensory terminal.
This causes greatly increased transmitter release, thereby markedly facilitating synaptic transmission.
Thus in a very indirect way, the associative effect of stimulation the facilitator neuron at the same time that the sensory neuron is stimulated causes prolonged increase in excitatory sensitivity of the sensory terminal, and this establishes the memory trace.

50. Associative learning Ex: Pavlov’s dog
Learning through long term memory of events
At neuron level: Long Term Potentiation  synapses are reinforced
And memory consolidation through protein synthesis

51. Classification of Memory
Memory can also be classified as:
Declarative-memory of details of an integrated thought
memory of: surroundings, time relationships cause & meaning of the experience
Reflexive (Skill)- associated with motor activities
e.g. hitting a tennis ball which include complicated motor performance

52. Higher Functions of the Brain
Behavior
Sleep and arousal
Emotions
Memory and Learning
Language
Personality

53. The first and second signaling system
The analysis and synthesis of the direct stimuli from surroundings first signal system performs. This includes impressions, sensations.
This functional mechanism is common in human and animals.
In the course of his social development and labor activity second signal system, which based on using verbal signals, develop.
This system includes perception of words, reading and speech.
The development of the second signaling system was incredibly broadened and changed quality of higher nervous activity of cerebral hemispheres.
Words are signals of other signals.
Man uses verbal signals for everything he perceives through the receptors.
Words are abstraction of reality and allow generalization, processing of surrounding primary information.
This gives the first general human empiricism and finally science, the instrument of man's higher orientation in the environment and its own self.
So, second signaling system is socially determined. Outside the society, without association with other people second signaling system is not developed.

54. Language and speech Language is dependent upon memory
Seeing and hearing words- dependent upon primary visual and auditory center functions
Speaking words-depends upon primary motor cortex function
Left and right cerebral hemispheres have different functions related to language and speech
Broca’s and Wernicke’s areas are only in the left hemisphere
Broca’s- ability to speak
Wernicke’s- ability to comprehend speech
Both hemispheres process information, but differently
Left is very specific
Right is very global

55. Nerve substrate of speech
There are two aspects of communication: sensory, involving reading, hearing of speech, and second, the motor aspect, involving vocalization and its control.
It is known, that lesion of posterior portion of the superior temporal gyrus, which is called Wernicke's area, and is part of auditory associative cortex, make impossible to the person to interpret the meanings of words.
This Wernicke's area is located in dominant hemisphere, which is usually the left.
The process of speech includes two principle stages of mentation: formation of thoughts to be expressed and motor control of vocalization.
The formation of thoughts is the function of associative areas in the brain. Wernicke's area in the posterior part of the superior temporal gyrus is most important for this ability.
Broca's speech area lies in prefrontal and premotor facial region in the left hemisphere.
The skilled motor patterns for control of the larynx, lips, mouth, respiratory system and other accessory muscles of speech are all initiated from this area.

56. Functions of speech
Main functions of speech are communicative, regulatory, programming and gives general notion about surroundings.
Communicative function permits exchange of information between people.
Such a function is also present in animals, which use for this aim vocalization of different intensity to warn about danger or express positive and negative emotions.
People use verbal signals for everything he perceives through the receptors.
Words are abstraction of reality and allow generalization, processing of surrounding primary information.

57. Higher Functions of the Brain
Behavior
Sleep and arousal
Emotions
Memory and Learning
Language
Personality

58. Type of nervous system
Type of nervous system determines rate of creation of new conditioned reflexes, strength and stability of these reflexes, intensity of external and internal inhibition, rate of irradiation and concentration of nervous processes, the capacity for induction and less or greater possibility for development of abnormalities of higher nervous activity.

59. Type of nervous system after I.P. Pavlov
I.P. Pavlov classifies types of higher nervous activity according to several attributes that considered as most reliable indices of higher nervous activity.
These were intensity of the excitation and inhibition, the ratio of these processes in central nervous system and their mobility, that is rate at which excitation was replaced by inhibition and wise versa.
In experimental practice the following four principle types of higher nervous activity are met:

60. 1) strong unbalanced type, characterized by predominance of excitation over inhibition;
Choleric temperament

61. Sanguinen temperament
2) strong well-balanced active type, characterized by high mobility of nerve processes;
Sanguinen temperament

62. Phlegmatic temperament
3) strong well-balanced passive type, characterized by low mobility of nerve processes;
Phlegmatic temperament

63. Melancholic temperament
4) weak type, characterized by extremely weak development of both excitation and inhibition, which cause fatigue and low workability.
Melancholic temperament