Psychology Sleep and Learning Quiz

Central Nervous System

• The central nervous system (CNS) is a complex network of nerves and cells that controls all body functions.
• EEG is a test used to evaluate the brain's electrical activity, useful for diagnosing neurological and sleep disorders.

EEG

• EEG is a study of electrical activities of the brain.
• An electroencephalogram (EEG) measures electrical activity of the brain, a complicated process due to many neurons and synapses, different from a single nerve fiber.
• Hans Berger, a German psychiatrist, was the first to systematically analyze EEG waves, which are now referred to as Berger waves.
• EEG helps diagnose neurological disorders during sleep, including epilepsy, midbrain disorders, and subdural hematoma.
• EEG patterns are altered in various neurological disorders.
• Common conditions that cause changes in EEG patterns include brain tumors, head injuries, encephalopathy, sleep disorders, herpes encephalitis, stroke, and Creutzfeldt-Jakob disease.
• Different types of EEG tests exist, including routine EEG (20–30 minutes), prolonged EEG (up to days), sleep EEG (over several hours during sleep testing), and ambulatory EEG (wore for one to three days).

EEG Recording Method

• Electroencephalograph is the instrument used.
• Scalp electrodes are placed on the scalp (unopened skull or opened skull) to record EEG, or pierced to skull to study the nervous system.
• Electrodes can be unipolar or bipolar.
• Unipolar uses one electrode over the cortex and an indifferent electrode on other part of the body away from cortex.
• Bipolar electrodes utilize two electrodes placed in different parts of brain.

EEG Waves

• EEG records synchronized or desynchronized waves.
• Synchronized waves are regular and invariant.
• Desynchronized waves are irregular and variant.
• Different frequency bands are recorded in normal persons, including alpha rhythm, beta rhythm, and delta rhythm.
• Children also show theta waves, with different characteristics.

Physiology of Sleep

• Sleep is a natural periodic state of rest for the mind and body.
• It is characterized by a partial or complete loss of consciousness.
• It leads to reduced response to stimuli and decreased body movements.
• Sleep depth varies throughout the sleep cycle.
• Sleep requirements vary by age: newborns (18-20 hours), growing children (12-14 hours), adults (7-9 hours), and older people (5-7 hours).

Physiological Changes During Sleep

• Most bodily functions slow down to a basal level during sleep.
• Plasma volume decreases by about 10% during sleep.
• Heart rate slows, typically fluctuating between 45 and 60 beats per minute during sleep.
• Respiration rate and force decrease and may become irregular, possibly with Cheyne-Stokes breathing.
• Salivary secretion decreases.
• Gastric secretion is not influenced or may slightly increase during sleep.
• Contraction of an empty stomach is more vigorous during sleep.
• Urine formation decreases, yet the specific gravity of urine increases.
• Sweating increases during sleep.
• Lacrimal secretion decreases during sleep.
• Muscle tone in almost all body muscles reduces, called sleep paralysis.
• Certain reflexes are abolished, while others, such as the Babinski sign, become positive during deep sleep.
• Brain electrical activity is also not inactive during sleep but demonstrates a characteristic cycle of irregular wave activity. It changes with sleep stages.
• Sleep types include rapid eye movement (REM) and non-rapid eye movement (NREM) sleep.

Types of Sleep

• REM (Rapid Eye Movement) sleep is associated with rapid eye movements. It's characterized as deep sleep, also called paradoxical sleep. It typically occupies roughly 20% to 30%.
• NREM (Non-Rapid Eye Movement) sleep is characterized by a lack of eye movement. It is also called slow-wave sleep, It occurs around 70%–80% of the sleep period. NREM sleep has various stages.

Mechanisms of Sleep

• Sleep is regulated by sleep inducing centers located in the brainstem, including Raphe nucleus and Locus ceruleus of Pons.
• Inhibition of ascending reticular activating system (ARAS) leads to sleep.

Applied Physiology - Sleep Disorders

• Insomnia: Inability to sleep or wakefulness.
• Hypersomnia: Excessive sleepiness or need for sleep..
• Narcolepsy: Sudden attacks of uncontrollable sleep.
• Cataplexy: Sudden emotional outburst often accompanying narcolepsy..
• Sleep apnea syndrome: Episodes of breathing cessation during sleep..
• Nightmare: Frightful dream during sleep episode, causing anxiety
• Night terrors: A sleep disorder in which the person screams due to fright and is semi-conscious,.
• Somnambulism ("sleepwalking"): Getting up and walking while asleep.
• Nocturnal enuresis: Involuntary urination at night (bedwetting).

Applied Physiology - Neurological Disorders

• Epilepsy: A brain disorder characterized by convulsive seizures and consciousness changes.
• Generalized Epilepsy: Excessive discharging of impulses from all parts of the brain..
• Grand mal epilepsy: Characterized by sudden loss of consciousness, followed by convulsive tonic and clonic stages..
• Petit mal epilepsy: Characterized by brief loss of consciousness without convulsive movements, with twitching facial muscles.
• Psychomotor epilepsy: Characterized by emotional outbursts like anger, anxiety etc. and loss of memory.
• Localized Epilepsy: Excessive discharging of impulses originating from a specific part of the brain.

Cerebral Cortex

• The cerebral cortex, also called the pallidum has two hemispheres.
• It has a surface area of 2.2 square meters in humans and is split by a deep vertical fissure (groove)
• The surface is characterized by sulci (grooves) and gyri (ridges).
• The cortex is divided into layers, each containing differing neuronal types.
• Six different types of layers are present. Layers of cerebral cortex include molecular layer, external granular layer, outer pyramidal layer, Internal granular layer, Ganglionic layer or internal pyramidal layer, and Fusiform Cell layer
• There are two major portions
• Neocortex (phylogenetically new): Has six layers.
• Allocortex (phylogenetically older): Has fewer layers and forms part of the limbic system..
• The cortex is divided into four lobes (fronto, parietal, occipital, and temporal) in each hemisphere..
• Key sulci and fissures (grooves): Separate regions. Includes central sulcus (Rolandic fissure), parieto-occipital sulcus, and lateral sulcus.

Cerebral Dominance

• Cerebral dominance refers to the functional dominance of one cerebral hemisphere over the other.
• In most people, the left hemisphere dominates, controlling aspects like language processing.
• Right hemisphere is involved more with artistic/creative and visuospatial skills.
• Handedness and language/speech-related issues are closely tied to cerebral dominance.

Cytoarchitecture : Brodmann Area

• Brodmann areas are characterized by cell organization patterns.
• Areas are numbered and have various functions based on area location.

Prefrontal Cortex/Orbital Cortex

• Prefrontal cortex, situated in the foremost part of cerebal cortex, is important for higher functions like emotion, social behavior, learning and memory
• Functions: Center for higher-level thinking, planning, and decision-making; Short-term memories are registered here; Emotions are regulated; Role in personality and intelligence
• Afferent and efferent connections exist (e.g. to and from thalamus, hypothalamus, midbrain, corpus striatum)
• Lesions in this area can result in decreased mental alertness and impaired initiation of activities.

Conditionally Reflexes

• Conditioned reflexes are acquired reflexes that involve associations. Learning and memory are involved
• Two types of classification: • Classical: Involves pairing a neutral stimulus with an unconditioned stimulus to evoke a conditioned response. • Instrumental: The animal learns to associate a behavioral response with a consequence (reward or punishment).

Types of conditioned reflexes

• Positive (excitation): Primary, Secondary, and Tertiary
• Negative (inhibition): External, Internal (studied further with extinction, conditioned inhibition, inhibition by delay, or differential inhibition).

Test your knowledge on sleep stages, types of learning, and memory. This quiz covers topics such as nightmares, sleepwalking, and types of epilepsy. Challenge your understanding of these psychological concepts through matching and multiple-choice questions.