Psych 381 midterm exam Questions and Answers

What is biopsychology? - ANS-- The study of the brain and how it affects behavior - Its purpose is to explain the relationships between brain and behavior The differences between animal brains and human brains: - ANS-- Animal brains: there are less ethical restrictions for doing research on them, but they can't follow instructions. It takes time to train the animals. We can compare them to human brains. Human brains: More cost effective, can follow instructions. *Main difference*: THE SIZE. Rat brains and human brains have all of the same main structures, but rat brains are smaller. - The human brain has a larger cortex. Importance of genetic diversity: - ANS-- Main point: It helps prevent the inheritance of genetic diseases (e.g. Huntington's disease). Because of this, less diseases are passed down and there is more variability in traits. 2 main divisions of the nervous system: - ANS-- Central Nervous System (CNS): The brain and the spinal cord Peripheral nervous system (PNS): Everything else that is not the brain and spinal cord Divisions of the peripheral nervous system: - ANS-- Autonomic nervous system & Somatic nervous system Describe the divisions of the autonomic nervous system: - ANS-- Parasympathetic: Rest and digest, conserve energy Sympathetic: fight/flight, mobilize energy, psychological arousal Describe the cardinal directions: - ANS-- Anterior: In front Posterior: In back Superior: Above Inferior: Below Dorsal & ventral: - When looking at the brain, the dorsal is the top of the brain and ventral is the bottom of the brain. - When looking from the neck down, the dorsal is towards the back (like a shark) and ventral is towards the front The distinction between afferent and efferent: - ANS-- - Afferent nerves move from the senses towards the CNS (ARRIVE) - Efferent nerves move away from the DNS towards the senses (EXIT) List the layers of the meninges from most superficial (furthest from the brain) to most deep (closest to the brain): - ANS-- Dura mater (hard mother): Hard protective outer layer Arachnoid membrane Subarachnoid space: consists mostly of cerebral spinal fluid (CSF) Pia mater (soft mother): thin membrane Role and function/location of CSF: - ANS-- Supports and cushions the brain - Found in spinal cord, ventricles, and subarachnoid space Describe the 3 different "cuts" of the brain: - ANS-- When looking at a subject in anatomical position- Sagittal: vertical slices (anterior to posterior) Axial: Horizontal slices (like the x axis) Coronal: (vertical slices but from side to side; like a crown) List the order of the "encephalon" brain structures: - ANS-- Telencephalon Diencephalon Mesencephalon Metencephalon Myelencephalon What the telencephalon is composed of: - ANS-- Cerebral cortex: high level processing Basal ganglia: motor control; it's within the cerebral cortex Limbic system: attention and motivation What the diencephalon is composed of, and those structure's functions: - ANS-- Thalamus: Sensory switchboard (receives signals from the receptors, processes them, and then transmits them to the appropriate areas of the sensory cortex) Hypothalamus: Plays an important role in the regulation of several motivated behaviors (e.g. eating, sleeping, and sexual behaviors). Does this by regulating the release of hormones from the pituitary gland. Another name for the mesencephalon is: - ANS-- the midbrain What the metencephalon is composed of: - ANS-- Cerebellum: fine motor control Pons: relays signals from the forebrain to the cerebellum; also other functions (e.g. sleep, respiration, swallowing, hearing, bladder control taste, etc.) What the myelencephalon is composed of: - ANS-- Medulla: breathing, heart rate; other autonomic functions Anatomy and function of the thalamus: - ANS-- Large, two-lobed structure that constitutes the top of the brain stem. It is the main structure for sensory information coming to the CNS. Anatomy and function of the Basal ganglia: - ANS-- Complex heterogeneous collection of interconnected nuclei (concentration of cell bodies). - involved in motor control; carries signals to and from the motor areas of the cortex - It has been shown to participate in (but is not limited to) habit learning. Anatomy and function of the cerebellum: - ANS-- Made up of lobes, columns, and layers. Contains more than half the brain's neurons! - involved in fine motor control; received information from primary and secondary motor cortex; plays a major role in motor learning, particularly in the learning of sequences of movements in which timing is a critical factor Function of the frontal lobe: - ANS-- Executive function: decision-making; focus attention; plan; remember instructions; juggle multiple tasks successfully Higher cognitive processing, learning, memory Planning, decision making, and emotion Difference between gyri and sulci: - ANS-- Gyri= curved parts; the ridges on the surface of the brain and located between fissures or sulci Sulci= depressions; the grooves on the surface of the brain. Note: large sulci are called fissures Main fissures of the brain and their location: - ANS-- Lateral fissure: between the frontal and temporal lobes Central fissure: Between the frontal lobe parietal lobe Anatomy of a neuron: - ANS-- Soma: the cell body of the neuron. The dendrites: signals are received through the dendrites; Postsynaptic potentials are elicited on the cell body and dendrites Axon: axons from many neurons are insulated from the extracellular fluid by segments of fatty tissue called myelin. Myelin sheaths: Myelination increases the speed of axonal conduction. Because conduction along the myelinated segments of the axon is passive, it occurs instantly ,and the signal thus "jumps" along the axon from node to node Process of action potentials firing: - ANS-- It begins with a stimulus. If the stimulus exceeds the threshold, then the sodium channel opens, causing sodium ions to rush into the cell, making the cell more positive on the inside. The potassium pump also opens, and potassium begins leaving the cell. This is called the rising phase. Once the peak has been reached, the action potential is fired. The sodium channels close immediately while the potassium channel closes very slowly. This is called the repolarization phase. Because of how slowly the potassium channel closes, more potassium leaves the cell, going even lower than resting membrane potential. This is called the hyperpolarization phase. Then the potassium channel officially closes, and diffusion of sodium causes the cell to be balanced back at resting membrane potential. Define saltatory conduction: - ANS-- The transmission of action potentials in myelinated axons (saltare means "to skip or jump"). Define action potential: - ANS-- a brief electrical charge that travels down an axon; If electrical stimulation of sufficient intensity is applied to the terminal end of an axon, an action potential will be generated and will travel along the axon back to the cell body Describe an EPSP: - ANS-- Excitatory postsynaptic potential. It is more positive so it makes it more likely that the neuron will fire an action potential. - Can get this through sodium entering the cell Describe an IPSP: - ANS-- Inhibitory postsynaptic potential. It is more negative, so it makes it less likely for the neuron to fire an action potential. - You can get this from potassium moving out of the cell or chloride coming in. Describe the process of synaptic transmission: - ANS-- 1) The action potential arrives at the axon terminal 2) Calcium enters the voltage gated ion channels 3) Calcium facilitates vesicle docking leading to exocytosis - Calcium then binds with the interior of the membrane and becomes a part of the membrane itself. The contents of the vesicle get pushed out into the synaptic cleft which is called exocytosis. 4) the neurotransmitter diffuses across the synaptic cleft, and binds to a receptor (channel protein) 5) EPSP (sodium channel) or IPSP (potassium channel) occurs, either exciting or inhibiting another action potential. Differences between agonists and antagonists: - ANS-- Agonists: enhance effects of neurotransmitters - likely by blocking reuptake (e.g. SSRIs) or by binding to receptor sites to activate them Antagonists: Stop the effects of neurotransmitters - likely by breaking down vesicles by enzymes to make them leak, or by binding to receptors sites but not to activate them (competitive binding). Describe the neurotransmitter GABA: - ANS-- Muscle tone (Major inhibitory) - synthesized from glutamate, an amino acid, calms down the excitatory system (think anti-anxiety). Describe the neurotransmitter glutamate: - ANS-- Memory/all over the brain (major excitatory) - amino acid Describe the neurotransmitter Acetylcholine: - ANS-- Memory/muscle-nerve interaction (excitatory) Has 2 types of receptors, and both are excitatory. - Nicotinic: skeletal muscles, ionotropic - Muscarinic: heart muscle, metabotropic How do monoamine oxidase inhibitors relate to neurotransmitters? - ANS-- They are anti-depressant drugs that increase the level of monoamine neurotransmitters (norepinephrine, serotonin, and dopamine) by inhibiting the action of the enzyme monoamine oxidase. Pros and cons of electrophysiological recordings: - ANS-- Temporal resolution: excellent Spatial resolution: excellent Invasiveness: very Cost: minimal Pros and cons of EEG: - ANS-- Temporal resolution: excellent Spatial resolution: poor Invasiveness: minimal Cost: minimal Pros and cons of MEG: - ANS-- Temporal resolution: Excellent Spatial Resolution: fair Invasiveness: minimal Cost: high Pros and cons of PET (positron emission tomography): - ANS-- Temporal resolution: poor Spatial resolution: fair Invasiveness: High cost: high Pros and cons of fMRI: - ANS-- Temporal resolution: poor Spatial resolution: fair+ Invasiveness: minimal Cost: medium Pros and cons of CT/CAT (computerized tomography): - ANS-- Temporal resolution: no function; quick structural scan Spatial resolution: fair Invasiveness: minimal How MRIs and fMRIs work: - ANS-- Measures blood flow to particular areas of the brain (but doesn't have a baseline for comparison). - uses a powerful magnet to align H protons in the body by emitting a radio frequency pulse that knocks the proteins out of alignment, and then measures the time it takes for the proteins to re-align. Different types of tissues have different re-alignment rates. Process of how vision travels from the eyeball to the primary visual cortex: - ANS-- 1) Cornea bends the light 2) light enters through the pupil 3) Iris regulates the size of pupil 4) Upside down image created on the retina 5) Retina transforms light to signals - light hits the back of the eye and bounces back, sending signals towards the front of the eye What is the cell order that light passes through in the retina? - ANS-- 1) retinal ganglion cells 2) amacrine cells 3) bipolar cells 4) horizontal cells 5) cone receptors and rod receptors. ** the light hits the receptors LAST Differences between rods and cones: - ANS-- Cones - Shape: tapered Number: 5 million Function: High acuity colored perception (in bright situations) - detailed and colored - not super sensitive because they can only respond in bright situations Rods- Shape: Cylindrical Number: 120 million Function: Lack detail and color (in dim situations) - More sensitive, detects motion in peripheral - night vision system - respond maximally green and related wavelengths The fovea consists solely of ___a. ___ while the peripheral retina has _____b. _________ - ANS-- a. cones b. both rods and cones, but more rods Receptive fields are: - ANS-- The area of the visual field within which it is possible for a visual stimulus to influence the firing of that neuron. Excitatory and inhibitory effects are found in receptive fields. Note: this is a property of the sensory neuron itself. Different neuron cells have different receptive fields (simple vs complex). Differences between ventral and dorsal streams: - ANS-- Ventral: Mediates the perception of WHAT things are (the what streams) Dorsal: Mediates the perception of WHERE things are (the where streams) What causes object agnosias? - ANS-- Damage to the ventral stream What is prosopagnosia and where in the brain is it associated with? - ANS-- Inability to distinguish faces from each other. The individual can tell a face is a face, but not whose face it is. - It is associated with damage to the fusiform face area, which is located between the occipital and temporal lobes. Damage to the parietal lobe: - ANS-- May affect a person's ability to navigate new spaces and understand language. Damage to the temporal lobe may cause: - ANS-- difficulty in forming explicit long-term memories while retaining the ability to form implicit long-term memories of the same experiences (medial temporal lobe amnesia) Damage to the occipital lobe may cause: - ANS-- low-level deficits such as Apperceptive agnosia- you can see lines and edges but can't put them together into an object (can't copy a picture). Patients with damage to their frontal lobes: - ANS-- seem to have great difficulty learning and remembering that previously appropriate guidelines for effective behavior are no longer appropriate, a problem called perseveration. A patient with cerebellar damage may: - ANS-- Lose the ability to control precisely the direction, force, velocity, and amplitude of movements and the ability to adapt patterns of motor output to changing conditions. It is difficult to maintain steady postures (like standing) and attempts to do so frequently lead to tremor. There are also severe disturbances in balance, gait, speech, and the control of eye movement. Learning new motor sequences is particularly difficult. The somatosensory cortex is located on: - ANS-- the postcentral gyrus of the parietal lobe Why is the transferring of motor control to "auto-pilot" advantageous to the brain? - ANS-- When you first learn something, it takes a lot of energy from the brain. Then it eventually becomes a habit so you don't have to think much about it, and it conserves energy. The basal ganglia in involved with this "muscle memory" (or the development of habits) What is motor homunculus? - ANS-- A drawing of a man that represents how many neuron cell bodies we have that innervate each region of our body. What is the somatosensory homunculus? - ANS-- sensory caricature of the body on the gyrus that represents the # of sensory neurons coming from each area of the body (hands, lips, and tongue tend to have the most sensory neurons) Describe the Grillner (1985) treadmill experiment: - ANS-- Grillner showed that with no input from the brain, the spinal cord can control walking motion. He used cats for subjects and put them on treadmills whose spinal cords had been separated from their brains and when the cats received sensory feedback when the treadmill was turned on, they began walking. Define a stroke: - ANS-- It is a sudden-onset cerebrovascular event. Causes: - Cerebral ischemia: When the blood supply is cut off to a certain part of the brain - Thrombosis: a plug forms in the brain - Embolism: a plug forms elsewhere and moves to the brain - Arteriosclerosis: wall of blood vessels thickens, usually due to fat deposits Briefly describe the differences between a generalized seizure vs a partial seizure: - ANS-- The entire brain or multiple brain structures are affected. VS Only one brain structure is affected. Describe a simple partial seizure: - ANS-- They are mostly sensory or motor; symptoms spread as epileptic discharge spreads. - Can be MOTOR seizures that cause change in muscle activity. These seizures can be SENSORY seizures that cause changes in any one of the senses. These seizures can be AUTONOMIC seizures that cause changes in the part of the nervous system that automatically controls bodily functions. These seizures can be PSYCHIC seizures that change how people think, feel, or experience things. - Awareness is preserved, memory is preserved, and consciousness is preserved Describe the types of a generalized seizure: - ANS-- Tonic-clonic - Aura: smell, hallucination, or feeling - Tonic phase: body becomes rigid - Clonic phase: convulsions Absence - Not associated with convulsions - A disruption of consciousness associated with a cessation of ongoing behavior Describe a complex partial seizure: - ANS-- Cause compulsive and repetitive behaviors (automatisms). May be preceded by a warning; often restricted to the temporal lobes. - Last 1 to 2 minutes. These seizures may have an aura (or warning). - Include automatisms (such as lip smacking, picking at clothes, fumbling), unaware of surroundings or may wander. -If awareness, memory, or consciousness Is impaired then it is considered this type of seizure Define a contusion: - ANS-- closed-head injuries that involve damage to the cerebral circulatory system. Such damage produces internal hemorrhaging, which results in a hematoma (bruise). - Occurs when the brain slams against the inside of the skull. --Frequently occur on the side of the brain opposite the side struck by a blow (also known as a contrecoup injury; because the blow causes the brain to strike the inside of the skull on the other side of the head) Define a concussion: - ANS-- When there is a disturbance of consciousness following a blow to the head and there is no evidence of a contusion or other structural damage, the diagnosis is this. Explain Parkinson's disease: - ANS-- A movement disorder of middle and old age affecting about 0.5% of the population. Symptom: most common symptom is tremor at rest/ Dementia is not typically seen; no single cause; associated with degeneration of the substantia nigra (these neurons release dopamine to the striatum of the basal ganglia Generally describe Alzheimer's Disease: - ANS-- Progressive degenerative disease; Most common cause of dementia; early stages characterized by confusion and a selective decline in memory. - Likelihood of developing it increases with age. - Definitive diagnosis only at autopsy; must observe neurofibrillary tangles and amyloid plaques Cognitive profile of Alzheimer's disease: - ANS-- Early changes: - Episodic memory; executive function, working memory and attention; language and semantic knowledge (lose words and vocabulary etc) Later changes - Visuospatial deficits, Decline across all cognitive domains Pathological hallmarks of Alzheimer's disease and highest risk factor: - ANS-- - Amyloid plaques (protein aggregates) - Neurofibrillary ranges (intracellular p-tau protein) Age is the number one risk factor for this disease. -Every 5 years after 65 the risk doubles -One in every 8 people over 65 will get AD -One in every 2 people over 85 will get AD Describe vascular dementia causes, cognitive profile, and risk factors: - ANS-- Vascular Dementia (VaD): widespread damage from "mini strokes: Also known as multi-infarct dementia. Caused by blockages in the brain's blood supply The 2nd most common form of dementia (behind alzheimer's) May cause or exacerbate Alzheimer's (complicates diagnosis as vascular factors contribute to AD) Cognitive profile: greater impairments than AD patients on executive function (planning goals). Less impaired on episodic memory (remembering facts and events) Risk factors: High blood pressure (about 50% of cases can be caused by hypertension Diabetes High cholesterol Family history of heart problems Obesity Smoking Describe multiple sclerosis: - ANS-- Progressive disease that attacks CNS myelin, leaving areas of hard scar tissue (sclerosis). - Nature and severity deficits vary with the nature, size, and position of sclerotic lesions - Periods of remission are common Symptoms include visual disturbances, muscle weakness, numbness, tremor, and loss of motor coordination (ataxia) Incidence of MS is increased in those who spend childhood in cool climates. Rare amongst Africans and Asians Only some genetic predisposition and only one chromosomal locus linked to MS with any certainty. Describe epilepsy: - ANS-- Seizures are symptoms of many problems. - Not all who have seizures have epilepsy - Difficult to diagnose due to the diversity and complexity of epileptic seizures -- likely a constellation of disorders Types of seizures - Convulsions: motor seizures - Some are merely subtle changes of thought, mood, or behavior Causes Brain damage Genes: over 70 known so far Faults at inhibitory synapses Diagnosis Gold standard: video EEG What are the physical effects of dementia on the inside workings of the body/blood streams? - ANS-- Lots of amyloid plaques and neurofibrillary tangles; loss of motor control What type of reflex is the patellar tendon reflex? - ANS-- Stretch reflex: - a reflex elicited by a sudden external stretching force on a muscle. Explain the findings of the study regarding monkeys and motor cortex neurons - ANS-- - It was found that the same stimulation of the motor cortex can produce opposite movements (depending on the starting position, but the end position of the movements remain the same) so - Each location in the primary motor cortex can produce innumerable patterns of muscle contraction required to get a body part from any starting point to any target location. What are the 2 types of motor control? - ANS-- Lower level: stuff that your body is ready to do such as reflexes, & biases to the system Higher level: Planned control (which can usually overcome these biases, if necessary) - Movement is usually a product of both Parietal and temporal cortex (relating to the motor cortex) is primarily involved in: - ANS-- coordination with sensory input The frontal cortex (relating to the motor cortex) is primarily involved in: - ANS-- Planning The basal ganglia (related to the motor cortex) is primarily involved with: - ANS-- balance; receives input from the cortex and feeds back to those same cortical areas The cerebellum (relating to the motor cortex) is primarily involved with: - ANS-- fine motor control/motor learning; skilled, voluntary movements, "forward models". Monitors e.g. "where my finger is and where I want it to go" and sends back feedback if you are on target or not. The spinal reflexes (relating to the motor cortex) are primarily involved in: - ANS-- speed and stability; Very fast and allow you to maintain posture and balance. An example is the patellar tendon stretch reflex.