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Psychology Notes! Module 4 Neural and Hormonal Systems

Neural Communication ● ● ● ● ●

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Biological Psychology- a branch of psychology concerned with the links between biology and behavior Neuron- a nerve cell; the basic building block of the nervous system Sensory Neurons- carry incoming information from the sensory receptors to the brain and spinal cord Motor neurons- carry outgoing information from the brain and spinal cord to the muscles and glands Interneurons- neurons within the brain and spinal cord that communicate internally and intervene between the sensory inputs and motor outputs

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Dendrite- receive information and conduct it toward the cell body Axon- passes the message along to other neurons or to muscles or glands Myelin Sheath- insulates the axons of some neurons and helps speed their impulses Action Potential- a neural impulse; a brief electrical charge that travels down an axon Resting Potential- the positive outside/ negative-inside state The axons surface is selectively permeable ○ Ex: a resting axon has gates that block positive sodium ions Action Potential figure:

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Signals are either excitatory, somewhat like pushing a neurons accelerator, or inhibitory,

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more like pushing its break. If excitatory signals minus inhibitory signals exceed a minimum intensity, or threshold, the combined signals trigger an action potential Thresholld- the level of stimulation required to trigger a neural impulse Neurons reaction is an all-or-none response ○ Ex: squeezing a trigger harder won't make the bullet go faster Synapse- the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron. The tiny gap at this junction is called the synaptic gap or synaptic cleft Neurotransmitters- chemical messengers that cross the synaptic gaps between neurons. When released by sending the neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neurons, thereby influencing whether that neuron will generate a neural impulse

The Nervous System ● ● ● ● ● ● ●

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Nervous system- the body's speedy, electrochemical communication network, consisting of all the nerve cells of the peripheral and central nervous systems Central nervous system (CNS)- the brain and spinal cord Peripheral nervous system (PNS)- sensory and motor neurons that connect the central nervous system (CNS) to the rest of the body Neurons are the nervous system’s building blocks Nerves- bundled axons that form neural “cables” connecting the central nervous system with muscles, glands, and sense organs Our peripheral nervous system has two components- somatic and autonomic Somatic nervous system- the division of the peripheral nervous system that controls the body’s skeletal muscles. Also called the skeletal nervous system

Autonomic nervous system- the part of the peripheral nervous system that controls the glands and the muscles of the internal organs. Its sympathetic division rouses; its sympathetic division calms. ○ Ex: like an automatic pilot, this system may be consciously overridden, but usually it operates on its own Sympathetic nervous system- the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations ○ It accelerates your heartbeat, raise your blood pressure, slow your

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digestion, raise your blood sugar, and cool you with perspiration, making you alert and ready for action Parasympathetic nervous system- the division of the autonomic nervous system Reflex- a simple, automatic response to a sensory stimulus, such as the knee-jerk response

The Endocrine System ● ● ●

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Endocrine system- the body’s “slow” chemical communication system; a set of glands that secrete hormones into the bloodstream Hormones- chemical messengers that are manufactured by the endocrine glands, travel through the bloodstream, and affect other tissues The nervous system ○ Zips messages from eyes to brain to hand in a fraction of a second ○ Delivers like an email Endocrine messages ○ Trudge along the bloodstream, taking several seconds to travel from gland to the target tissue ○ Snail mail ○ Tend to outlast the effects of neural messages Adrenal glands- a pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress Endocrine systems hormones ○ Influence growth, reproduction, metabolism, mood, etc. ○ Works with the nervous system to keep everything in balance while we respond to stress, exertion, and our own thoughts Pituitary gland- the endocrine system’s most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands ○ Master endocrine gland ○ Ex: under the brains influence, the pituitary triggers your sex glands to release sex hormones ○ nSystem: yss brainpituitar yother gland shormone sbrain The nervous system directs endocrine secretions, which then affect the nervous system

Module 5

Tools of Discovery and Older Brain Structures

The Tools of Discovery: Having Our Head Examined ● ●

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Lesion- tissue destruction. A brain lesion is a naturally or experimentally caused destruction of brain tissue Electroencephalogram (EEG)- an amplified recording of the waves of electrical activity that sweeps across the brain's surface. These waves are measured by electrodes placed on the scalp

How it works: by presenting a stimulus repeatedly and having a computer filter out brain activity unrelated to the simulis’, one can identify the electrical wave evoked by the stimulus PET (positron emission tomography) scan- a visual display of brain activity that detects where a radioactive form of glucose goes while the brain performs a given task ○ Locates radioactivity ○ Shows which brain areas are most active as the person performs mathematical calculations, looks at images of faces, or daydreams

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MRI (magnetic resonance imaging)- a technique that uses magnetic fields and radio waves to produce computer generated images of soft tissue. MRI scans show brain anatomy. ○ Shows the brains soft tissue

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fMRI (functional MRI)- a technique for revealing blood flow and, therefore, brain activity by comparing successive MRI scans. fMRI scans show brain function. ○ Detects blood rushing to the back of the brain , which processes visual info.

Older Brain Structures ●

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The brain system- the oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull; the brainstem is responsible for automatic survival functions Medulla- the base of the brainstem; controls heartbeat and breathing Pons helps coordinate movements Reticular formation- a nerve network in the brainstem that plays an important role in controlling arousal ○ Inside the brain system, extends from the spinal cord right up to the thalamus brainstem Spinal cord- pathway for neural fibers traveling to and from the brain; controls simple reflexes Thalamus- the brain's sensory switchboard, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla ○ Sits at the top of the brainstem ○ Relays messages between lower brain centers and cerebral cortex Cerebellum- the “little brain” at the rear of the brainstem functions include processing sensory input and coordinating movement output and balance ○ Baseball sized ○ Coordinates voluntary movement and balance and supports memories of such ○ Enables one type of nonverbal learning and memory ○ Coordinates voluntary movement ○ Ex: If my cerebellum was damaged I wouldn't be able to walk properly and I would probably have jerky movements. Like Robbie from Victorious when he had to pretend to have jelly legs for an assignment Limbic system- neural system (including the hippocampus, amygdala, and hypothalamus) located below the cerebral hemispheres; associated with emotions and drives

Amygdala- two lima bean-sized neural clusters in the limbic system; linked to emotion

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When the amygdala is removed you turn mellow, placid, nothing will bother you or set you off ○ Has a huge roe in rage and fear Hippocampus- linked to memory Hypothalamus- a neural structure lying below (hypo) the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward ○ Monitors blood chemistry and takes orders from other parts of the brain The brain influences the endocrine system, which in turn influences the brain

Rat experiment- with an electrode implanted in a reward center of its hypothalamus, the rat readily crosses an electrical grid, accepting the painful shocks, to press a pedal that sends electrical impulses to that center

Module 6 The Cerebral Cortex and Our Divided Brain

The Cerebral Cortex ●

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Cerebral cortex- the intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body's ultimate control and information-processing center ○ Brains thinking crown ○ The larger the cortex the more capabilities it has ○ Contains 20-23 billion nerve cells and 300 trillion synaptic connections Glial cells (glue cells)- cells in the nervous system that support, nourish, and protect neurons ○ Plays a role in learning and thinking Neurons are like queen bees. Glial cells are worker bees- provide nutrients, insulate myelin, guide neural connections, and mop up ions and neurotransmitters Frontal lobes- portion of the cerebral cortex lying just behind the forehead; involved in speaking and muscle movements and in making plans and judgements Parietal lobes- portion of the cerebral cortex lying at the top of the head and toward the rear; receives sensory input for tough and body position Occipital lobes- portion of the cerebral cortex lying at the back of the head includes areas that receive information from the visual fields Temporal lobes- portion of the cerebral cortex lying roughly above the ears; includes the auditory areas, that receiving information primarily from the opposite ear

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Motor cortex- an area at the rear of the frontal lobes that controls voluntary movements Sensory cortex- area at the front of the parietal lobes that registers and processes body touch and movement sensations The visual cortex of the occipital lobes at the rear of your brain receives input from your eyes. The auditory cortex, in your temporal lobes- above your ears- receives information from your ears Association area- area of the cerebral cortex that are not involved in primary motor or sensor functions; rather, they are involved in higher mental functions such as learning, remembering, thinking, and speaking ○ Found in all four lobes ■ Frontal lobes- enable judgement, planning, and processing of new memories ■ Parietal lobes- enable mathematical and spatial reasoning Plasticity- the brain's ability to change, especially during childhood, by recognizing after damage or by building new pathways based on experience ○ Especially evident after serious damage Neurogenesis- the formation of new neurons

Our Divided Brain ● ● ●

The left hemisphere is the “dominant” or “major” hemisphere Corpus callosum- the large band of neural fibers connecting the two brain hemispheres and carrying messages between them Split brain- a condition resulted from surgery that isolates the brains two hemispheres by cutting the fibers (mainly those of the corpus callosum) connecting them ○ Leaves you with two separate minds, one side doesn't take into account what the other side just did or saw

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Ex: if a patient follows an order sent to the right hemisphere the left doesnt know whats

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happening, then the left improvises to come up with a reason why they are doing that order The left is an interpreter; it is more active when people are deliberating over decisions The right understands simple requests, easily perceived objects, and is more engaged quick, good at perceiving emotion, bad at processing emotion and social conduct

Right-Left Differences in the Intact Brain ●

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Right ○ Perceptual tasks: brain waves, blood flow, and glucose consumption ○ Making inferences ○ Modulate our speech to make meaning clear ○ Orchestrates our sense of self Left ○ Speaks or calculates ○ Process sign language bc it typically processes language The mid is seeking to understand the brain

Module 17 Introduction to Sensation and Perception ● Sensation- the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment ● Perception- the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events ● Bottom-up processing- analysis that begins with the sensory receptors and works up to the brain’s integration of sensory information ● Top-down processing- information processing guided by higher-level mental processes, as we construct perceptions drawing on our own experience and expectations

Thresholds ● ●

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Psychophysics- the study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them Absolute threshold- the minimum stimulation needed to detect a particular stimulus 50 percent of the time ○ Ex: For hearing it would detect a really high pitched sound and it may vary for age Signal detection theory- a theory predicting how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise). Assumes there is no single absolute threshold and that detection depends partly on a person's experience, expectations, motivation, and alertness ○ With such heightened responsiveness come more false alarms ○ When survival is not threatened, people would require a stronger signal before sensing danger ○ The point at which we detect a stimulus half the time Subliminal- below one’s absolute threshold for conscious awareness

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Priming- the activation, often unconsciously, of certain associations, thus predisposing one’s perception, memory, or response ○ Sometimes we feel what we do not know and cannot describe ○ Much of our information processing occurs automatically, out of sight, off the radar screen of our conscious mind Difference threshold- the minimum difference between two stimuli required for detection 50 percent of the time. We experience the difference threshold as a just noticeable difference (or jnd) Weber's law- the principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant amount)

Sensory Adaptation ●

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Sensory adaptation- diminished sensitivity as a consequence of constant stimulation ○ Ex: you walk into a room with a musty smell and you don't like it, then a few moments later you no longer smell it We perceive the world not exactly as it is, but as it is useful for us to perceive it

Module 18 Vision ● Transduction- conversion of one form of energy into another. In sensation, the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brains can interpret

The Stimulus Input: Light Energy ●

A slice of the electromagnetic spectrum is a way we can see visible light

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Two physical characteristics help determine our sensory experience of them, wavelength & intensity Wavelength- the distance from the peak of one light or sound wave to the peak of the next. Electromagnetic wavelengths vary from the short blips of cosmic rays to the long pulses of radio transmission Hue- the dimension of color that is determined by the wavelength of light; what we know as the color names blue, green, and so forth ○ The color we experience Intensity- the amount of energy in a light or sound wave, which we perceive as brightness or loudness, as determined by the waves amplitude

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The Eye ●

Pupil- the adjustable opening in the center of the eye through which light enters

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Iris- a ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening in the center of the eye ○ Adjusts light intake Lens- transparent structure behind the pupil that changes shape to help focus images on the retina Retina- the light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information ○ A multi layered tissue on the eyeballs sensitive inner surface Accommodation- the process by which the eyes lens changes shape to focus near or far objects on the retina

Rods- retinal receptors that detect black, white, and grey; necessary for peripheral and twilight vision, when cones dont respond Cones- retinal receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. The cones detect fine detail and give rise to color sensations ○ Help you perceive color Blind spot- the point at which the optic nerve leaves the eye, creating a “blind” spot because no receptor cells are located there Cones cluster in an around the fovea Fovea- the central focal point in the retina, around which the eyes cones cluster Bipolar cells relay the cones individual message to the visual cortex Rods share the bipolar cells

Visual Information Processing ● ● ● ● ●

Retina processes information before routing it via the thalamus to the brain's cortex The retina's neural layers pass along electrical impulses, and encodes and analyzes the sensory information David Hubel & Torsten Wiesel demonstrated that neurons in the occipital lobes visual cortex receive information from individual ganglion cells in the retina Feature detector- nerve cells in the brain that respond to specific features of the stimulus, such as shape, angle or movement Parallel processing- the processing of many aspects of a problem simultaneously; the brain's natural mode of information processing for many functions, including vision. Contrasts with the step-by-step (serial) processing of most computers and of conscious

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problem solving ○ The braindivies a visual scene into subdimensions (color, movement, form, depth, ect.) A simplified summary of visual information processing ○ Scene ○ Retinal processing: receptor rods and cones- bipolar cells- ganglion cells ○ Feature detection: brains detectory cells respond to specific features--edges, lines, and angels ○ Parallel processing: brain cell teams process combined information about color, movement, form, and depth ○ Recognition: brain interprets the constructed image based on information from stored images

Color Vision ● ●

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Color resides not in the object but in the theatre of our brains Young-Helmholtz trichromatic (three-color) theory- the theory that the retina contains three different color receptors- one most sensitive to red, one to green, one to bluewhich, when stimulated in combination, can produce the perception of any color When we simulate combinations of these cones, we see other colors Afterimage shows you th...