Nervous System Divisions

• Functional divisions of the nervous system include neurons in the spinal cord and sensory neurons, which bring sensations from the body into the spinal cord.
• The nervous system is divided into the central nervous system and the peripheral nervous system.

Central Nervous System

• Consists of the brain and spinal cord.

Peripheral Nervous System

• Located on the outer edges or outside of the body
• Includes the somatic nervous system and the autonomic nervous system.

Somatic Nervous System

• Associated with the soma (cell body of a neuron)
• Controls somatic muscles attached to our bones
• Involves conscious control or knowledge
• Example: feeling someone touching your skin.
• Afferent nerves carry information towards the brain, acting as sensory neurons
• Efferent nerves carry information away from the brain for motor control
• Skeletal muscles attach to this system.

Autonomic Nervous System

• Operates outside conscious knowledge or control
• Involves organs communicating with each other
• Takes sensory information from organs like the heart, lungs, and kidneys
• Afferent nerves carry information towards the brain
• Efferent nerves carry information away from the brain
• Motor control extends to smooth muscles (intestines, heart, etc.), and is outside conscious control.
• Contains the sympathetic and parasympathetic nervous systems.

Autonomic Nervous System Details

• Sympathetic mobilize energy for fight or flight responses
• Example: On a first date, the sympathetic system is highly active, slowing down digestion.
• Parasympathetic conserves energy by resting and digesting, and storing energy for the future
• These systems are not always mutually exclusive.

Simple Reflex

• Considered a good model which involves bringing sensory information in and quickly sending motor information out
• Example: Burning your finger
• Receptors in the skin sense the environment and information is quickly taken into the spinal cord
• In the spinal cord, the axon synapses onto an interneuron, which then synapses onto a motor neuron.
• The motor neuron sends information back to the finger to retract it from the hot stimulus
• The brain is not required to pull away from dangerous stimuli Need to respond quickly without waiting for sensory signal processing
• This is an immediate response

Immediate Response Info

• Sensory information eventually reaches the brain, but not initially
• Movement occurs before conscious realization
• This is a fast and protective mechanism to protect the body

Endocrine System

• Functions via a feedback system
• Brain → pituitary gland → other glands → hormone release → effects on the body and the brain
• Reveals the interplay between the nervous and endocrine systems
• Hormones serve as chemical messages released from glands into the blood
• The brain interacts with the endocrine by the pituitary gland (master gland) Where there is the main intersection between the nervous system and the glands Which sends messages to other glands
• The brain controls hormonal release

Hormone Release Effects

• Developmental: Changes or shapes a man's physiology, differentiating it from a woman's physiology.
• Functional behavior: Less clear in humans, but clear in songbirds and iguanas during mating season
• Ultimately shapes brain development.

Major Brain Divisions

• Early in development, three swellings appear
• Forebrain
• Midbrain
• Hindbrain, which connects to the spinal cord

Evolutionary History

• Human brains feature a massive forebrain accompanied by normal sized midbrain

Dividing the Brain

• A five-tiered system is a way to divide the brain
• Forebrain divisions: Telencephalon, diencephalon
• Midbrain division: Mesencephalon

Forebrain

• Telencephalon structures: cortex, hippocampus, amygdala.
• Diencephalon: Directly connected to the brain stem.

Midbrain

• Mesencephalon, part of Hindbrain

Hindbrain Divisions

• Metencephalon structures: cerebellum, which is important for coordination and balance
• Myelencephalon structures: medulla, which is vital for basic biological processes
• Keeping the heart beating
• Cerebellum is a portion of the hindbrain

Brain Structures

• Most conscious experience occurs in the telencephalon
• Information in the diencephalon and mesencephalon is not accessible to consciousness.

Telencephalon

• Largest division of the brain
• The cerebral cortex is the most prominent constituent
• The cortex is highly convoluted (wrinkled) which increases surface area while maintaining a small volume
• Human brains are highly convoluted although many mammals are lissencephalic (smooth-brained)
• Large furrows in the cortex are either fissures or sulci (sulcus)
• Ridges between fissures are called gyri (gyrus)

Fissures

• The largest of all the fissures is the longitudinal fissure
• Separates the left and right hemispheres
• Cerebral hemispheres connect via a few tracts called cerebral commissures
• The largest tract is the corpus callosum.

Limbic System

• On the border of the system and doesn't work together as one unit, with few areas
• Amygdala: Important for learning, memory, and emotional structure
• The Latin word for almond.
• Hippocampus: Latin for "sea horse."; major structure in explicit memory Conscious knowledge and is important for explicit long-term memories.
• Cingulate cortex: Involved in mustering effort and making hard decisions Important for autobiographical memory or being introspective.

Basal Ganglia

• Composed of two regions
• Caudate and Putamen, sometimes referred to as striatum
• Modulates motor output, and is critical to habit formation
• Plays cognitive roles, promotes skill learning, involved in addiction
• Contributes to muscle memory
• Important role in developing habits.

Lobes of the Cortex

• Two major landmarks: central fissure and lateral fissure
• Four lobes: occipital, temporal, parietal, frontal.

Occipital Lobe

• Processes visual information
• Located in the back of the brain

Temporal Lobe

• Helps with hearing, memory, and language
• Located behind the ears.

Parietal Lobe

• Processes the sense of touch
• Assembles input from other senses

Frontal Lobe

• Voluntary movement, expressive language
• Thinking, movement, and social skills
• Involved in personality, decision making, and emotional regulation.

Layers of the Brain

• Layers of the cortex with 6 layers
• All containing cell bodies
• Layers 1 and 2 have fewer cells, and Layer 4 can be thick.
• Depending on the brain region, the 6 layers differ in appearance
• Each layer has slightly different functions
• Layer 4: an important input structure especially for sensory systems
• If thick or dark, it indicates a sensory area.

Primary Motor Cortex

• The homunculus is located here
• Motor cortex mapping, discovered by Foerster and Penfield, determined that body areas requiring precise control take up the largest part of the cortical space.
• Electrical stimulation of the motor cortex can cause body part movement.
• The brain is contralaterally organized
• The left controls the right half of the body
• The right controls the left half of the body
• The brain has maps of the body and the world
• Illustrating cortical magnification

Brain Usage

• Entirely used by humans

Controlling Voluntary Movement

• Prefrontal cortex
• Motor cortex
• Basal ganglia

Brain Structures

• Pons: Area where axons travel through
• Cerebellum
• Medulla

Cerebral Blood Flow

• The brain has limited access points for blood
• Four Arteries:
• Internal carotid arteries travel on the left and right, along the front of the neck
• Vertebral arteries travel on the left and right, along the back near the spine
• Damage to these arteries is devastating
• The arteries are all separate so if one is damaged there is no backup
• The brain doesn't store energy, constantly needs oxygenated blood and glucose
• It will quickly die without energy
• The brain's circulatory system is susceptible to circulatory system damage.

Blood-Brain Barrier

• Capillary (general) structure: Capillary wall on each side with pores for movement in and out of the blood.
• Capillary (brain) structure: Tightly packed capillary wall with no space between cells and tight junctions.
• Astrocytes have feet that wrap around blood vessels to prevent anything in the blood from getting out
• An astrocyte and wall form a blood-brain barrier.
• Special transport is needed to get oxygen or glucose into the body
• Barrier determines drug helpfulness/effectiveness.

Skull Meninges

• When cracking open the brain, a very tough pillow case is seen
• This surrounds the brain, known as the dura mater
• Known as the "tough mother" of thick material that makes the outermost layer
• The spider webby substance: Arachnoid mater/membrane.
• The spider mother is hard to perceive
• Closer to the brain is the pia mater
• A thin, shiny, clear layer that closely hugs the brain
• Fluid is found between the arachnoid mater and pia mater.

Brain Protection

• Meninges protects the brain
• Cerebrospinal fluid (CSF) in ventricles acts in between the arachnoid mater and pia mater wrapped around acting like an airbag
• There is a lot of CSF inside the brain inside spaces called ventricles
• The fluid itself provides a nutritional role and also moves waste from the brain
• Four ventricles exists:
• 2 lateral
• Third ventricle
• Fourth ventricle
• CSF acts as a cushion system and slows down the kinetic force of the brain hitting the skull or brain tissue
• Prevents major damage via CSF

Brain Plasticity

• Severed brain and spinal cord neurons usually don't regenerate
• Some brain functions seem preassigned to specific areas
• Some neural tissues can reorganize after damage and plasticity may occur after serious damage Neuroplasticity Nearby neurons can take on the role of lost neurons The flexibility of neurons to do other things in different roles

Brain Plasticity details

• Constraint-induced therapy aims to rewire the brain and improve the dexterity of brain-damaged people
• Blindness or deafness makes unused brain areas available for other uses Similar reassignment occurs when disease or damage frees up areas traditionally dedicated to specific functions.

Sensation/Perception concepts

• Sensation and perception are part of one continuous process in normal circumstances
• Sensation: nervous system represents external energies from the environment Detects stimulus energies using specialized cells and proteins
• Perception: organization and interpretation of sensory information An organized whole is sensory info
• Bottom-up processing: moves from external world inward from most basic to perceptions Detects energy and organizes the signal more and more

Processing Details

• Top-down processing: knowledge and expectations shape how the world is perceived
• There is an idea about the world so we go out looking for that idea and expect to find it
• Results in a rich simulation of the world in our minds and confirmation bias as with anticipating words in a conversation
• Senses receive sensory stimulation via specialized receptor cells and transform that stimulation into neural impulses via transduction Converting one energy form into another and delivering the neural information to the brain Example: hair cells only detect one type of thing The goal is to detect energies in the environment
• Psychophysics: Understanding relationships between the physical and psychological world

Additional Definitions

• Signal detection theory: ability to detect a stimulus with noise in the environment where neurons are noisy Example: asking if a friend said something when they didn't
• Individual absolute threshold: the point where a single person can detect the stimulus more than 50% of the time
• Absolute threshold: minimum intensity needed to just barely detect a stimulus in 50% of the trials Measured by the use of many participants and with all same external variables

Sensation

• Absolute threshold will change based on external variables based on the environment
• Subliminal refers to sensation below the edge to where it isn't detected 50% of the time Reaching nervous system but not reaching the level of consiousness
• Priming: activation of association in our minds Example: Using the same fancy word over and over again
• Difference threshold, aka just noticeable difference (def), is the minimum difference between the stimuli that someone can detect

Perception Concepts

• Weber's law states that it's easier to differentiate light weights than heavy weights
• Needs proportionate difference to differentiate by minimum percentage Example: Whispering in a quiet room versus shouting in a loud one to differentiate the background noise
• Subliminal stimuli is too weak for you to detect more than 50% of the time More likely to miss it ex. Fed Ex arrow
• Subliminal sensation: so brief you don't consciously detect it

How We Perceive

• Influence behavior and can affect us
• Subliminal does arrive to a brain
• Sensory adaptation: sensitivity diminishes as a consequence of constant stimulation No new information so it starts to be ignored Increases focus by reducing background chatter As a result the world is perceived in a personally useful way
  • This serves to tune the signal-to-noise ratio This can be for emotions as well The minute the information is useful, they focus on it Example: a spider crawling on us and yu swat it off, after everytime you feel a sensation on your foot you'll focus on it again and look down

Emotion

• If you are surrounded with negative people, the positive person sees extremely nice.
• Perceptual set is what determines that
• Schemas are the way the information is stored in our head
• Context effect:
• The way we see the world determined by what we're exposed to in our cultures are called culture
• Motives: Working toward a goal changes how we see perceptual information
• Something can be perceived as good or bad

Vision

• Wavelength: vaguely related to colour Longer waves will be perceived as reddish, and shorter waves blueish (not colour)
• Hue: colour
• Intensity: size of the waves
• Amplitude: Larger is brighter/ smaller is dimmer.
• Frequency: Longer wavelengths equals lower frequency while shorter wavelengths equal higher frequency Which depend on the amount of the Waves.
• What is seen as light is only a thin slice of the broad spectrum of electromagnetic energy.

Visual Information

• Light energy: from the environment into the brain
• Frequency: longer wavelengths lower frequency / shorter wavelengths higher frequency
• Amplitude: Retina and also the back of the eye
• Accommodation: Changing the angle of the light and what the lens does
• Not landing on the retina that means you have myopia( Retina is further back then it should be)
• Rods and cones provide special sensitivities:

Rods

• Sensitive to faint light; uses for your night vision
• During the day theyre so bright they dont function
• One type of rod and three types of cones
• They produce differently
• Cones Cones are in charge with detail and color and are used in daylight They have 3 different types; they can percieve color

Light

• How does light enter to the brain
• Important: Visual information from the right half of the world is processed in the left hemisphere of the brain and vice versa

Information Processing

• Colour processing Young helmholtz are able to reproduce every colour of light humans can perceive through a combo of 3 colours
• Red, green and blue light: when you shine all these colours together equally it shows white light if you can make all the colours we perceive that means we much have 3 types of colour sensing cells (3 cones) Hering opponent process theory
• Feature detection (def) for parallel processing is much faster Hubel and wiesel

Visual Information details

• Traveles chrome occipital lobe to both parietal lobe and temporal lobe Specialized processing for different perceptual information Dorsal pathway The how pathway Is interested in aspects of location, depth and movment
• Ventral pathway: The what pathway Interested in form, colour, and shape Identifying a hammer vs a saw
• Vision: visual organization How do we organize and interpret shapes and colours to create meaningful perceptions

Visual Cues

• Proximity the idea that things close together are more likely to be grouped together/related Continuum Perceived objects as continuous or smoothly flowing lines even when parts are milling or obscured
• Closure Fill in parts Figure-ground Group things together meaningfully
• ex. Group of feathers together we assume its from the same bird perceptual constancy Tools for seeing things a consistent

Visual Dimensions

• Depth perception Is only two dimension The visual cliff experiment Babies crawl until the “edge” and they stop Your depth deception forms when you're able to move around in the world Sees depth and binocular cues Uses two eyes Improves depth

Binocular Cues

• Retinal disparity is a binocular The brain calculates distance by comparing images from the 2 eyes Can be used by 3D film makers
• Looks at how the something fall on retina The more retina disparity should be closer

Monocular Depth Cues

• Available through the one eye
• Light and shadow
• Relative motion Aka Párallax Objects close to use moves quickly and vice versa
• ex. Driving you see the road but slow in the monutains
• Relative Size Near is bigger and further is smaller
• Relative Height Tings that are further away tend to be higher up in your visual field
• Linear Perspective As things get further away all those lines start to converge

Object Recognition

• Interposition One full thing in the one we think are clear are further away Humnan's imperfections Humans are often imperfect with motion.
• Phi/beta phonomen Creates more adjacent lines that blink on Creates more film

Visual Features

• Humans are imperfection but a good sense of film makers Perceptual construcy can be construcy Colour constantcy Size constance
• the ability to percieve colours constant Restored vision What they go though to develop Perceptual adaptation
• the ability we adjust to changed senesory Sound will compress and we percieve From envirment to brain Hering Sound and characterization

Audio Information

• We are interprete from pressure Pitch Is related wavelngth Is the transform energy to sound 3 tiny bones in the ear attached the drum Hearing, decoding sound waves Waves strike the eardrum its going to vibrat Ripples bend cause imoulsel

Audio Perception

• Place theory in better hearing for the pitch, where can it go right We her the frequency but it is the patch More is a patch How easy we her What theory we know The delay sounds and more

Sense of Hearing

• 2 hear are better then one and can have Allow can tell the furniture tell you if there is hardood Arrvie the one drum allows you to tell when That frequency through hearing is you get One her has more contnet

Defining consciousness

• Represents the awareness and experience thoughts Coniciousness is subjective the my experience is not that different then others Hards of acusecs.
• the subjective, and personal thing consciousness is abot something and have no contents know your one and bad multitaskers

Consciousness Qualities

• Body awareness that allows you to recgonize what you are doing.
• Agenecy is how have control over other things

Consciousness Characteristics

• self awareness you are aware that that person is able to awware
• Metacosiveness You can thank of different things Consciouseness is an like all human feature Different states of consciosuens Con. is not fixed thout the day

Thoughts

• Conscisenouss i not fixed throughout the day 3 approach not a naturel phonmen Natural phone not be measuered and is not measured recent consciosuens of the bran activity

• Bilologu of conn cognitive neuro scientist find and read minds and see brains activity people can get answers thought FMAR

• Bibile STUIMULUS Necker cube Have no firm rabit

Brain Facts

• You canot the duck and rabbit because it only show in ventral parway Prolbms in conscisiunus What are the neural cots are The ability of consiousness Why cant we fee conscious

Neurological Condition

• ANTRAGRODE For wards not back Blinding Some people cannot see constiuty
• some problem lack of knowledge what is the problem with aiblity you cant see basic aspecys reaped relates to processing parrele

More Conditions

• Nego the brain test if there are many lies tell the brain
• do not detect the lies
• you go up or dont do that They hope they are doing what their
• Dul Processing the ability to what thing are and see you damage something to the concious The that you can tell where the thing are and how
• which is why split brain is a big this

Split Brain Procedure

• People see there damage from lobes in motor that what a split brain has two different heremssphier can’t read stuff or you but draw stuff
• Selectious attentiuos
• the ablity

Learning

• All we learned is lost, and we don’t focus We cat mean process It is not easy a s always so not that
• The diotic Is that on is never close saliant more imporatn and that even it that does not mater you know what is sad
• Selective activities that happens is an accidents

Models

• the way we drive has effect the brain and we don’t what do the car 37 % if a part us go do somethign they go down so driving and talking on the phone doesn't do that
• filters theory of All or nothing you go through. Showed that the other

Theories

• Attenution Models of
• Selctive atteion of visual stimulant
• Parner et all

Attention

• Is are a the one or other thing One or port reouscues The minute you one and there problem
• The minuet will be a big problem
• But it is not that is one or the other so problems one is big so we go to other and not just one a other one at the other time Multipel Resouce moude all the thing we see have multipel and we get divide our thing

Vision Complications & Organization

• Operationally will all the test use the is it that the W e do not have the theroy of how this Orgizant of the They are major duviso

Structure

• the central nerous system comprsred of the one or there receives and cordants the and does more

Nerve's

• The nerve system what carries commands, where does the nerve somtimes that do not talk to all system and what not you see system to what can the what no system the nervs you the body

More

• comprsed of a main sudvicion the body will happen prepares of act to have these cordant cordant what the what

System Summary

• The main of system we study is the The area of thing with the body This are just a few

Neural Operation

→ simple pathways in the nervous system that rapidly generate muscle contractions

• location with the extent of the abilities lost
• Medulla and all of the thing around it
• Poms

Tectum Function

• Orient an organism in the environment
• Helps orient an organism towards sensory stimuli
• Involved in arousal, mood, motivation fore brain
• Hignest level of the brain
• dived to main setin
• cerbectcal corex