Physiological Psychology Flashcards
Brenda Milner
British-Canadian neuropsychologist who has contributed extensively to the research literature on various topics in the field of clinical neuropsychology, and is sometimes referred to as the founder of neuropsychology. In particular, she studied the severe anterograde amnesia of H. M.
Limitations of Schachter and Singer’s
Two-Factor Theory of Emotion
Schachter and Singer’s two-factor theory has attracted a good deal of controversy, as some studies have corroborated their findings but others have not. Overall, it now appears that one limited but important conclusion can be drawn: When people are unclear about their own emotional states, they sometimes interpret how they feel by watching others. The “sometimes” is important. For other people to influence your emotion, your level of physiological arousal cannot be too intense or else it will be experienced as aversive, regardless of the situation. Also, other people must be present before the onset of arousal.
Schachter-Singer Two-Factor Theory of Emotion
Stanley Schachter and J. E. Singer proposed that the subjective experience of emotion is based on the interaction between changes in physiological arousal and cognitive interpretation of that arousal, which is influenced by the situational context. They conducted a famous experiment in which they injected subjects with epinephrine (under various conditions of disclosure or misinformation) and had a confederate model behavior that was either euphoric or angry. The results supported the hypothesis: drug-uninformed participants reported feeling relatively happy or angry depending on the confederate’s performance.
Cannon-Bard Theory of Emotion
Walter Cannon and Philip Bard, objecting to the James-Lange Theory, argued that physiological changes and subjective feeling of an emotion are separate and independent; arousal does not have to occur before the emotion. In particular, they proposed that emotional expression results from the function of hypothalamic structures, while emotional feeling results from stimulations of the dorsal thalamus. The Cannon-Bard theory is also referred to as the thalamic theory of emotion. Cannon discovered that any activation of the sympathetic nervous system essentially produces the same physiological response. Cannon and Bard thus argued that subjective experience of emotion implicates specific neural circuits in the brain, with different circuits corresponding to different emotions, and that emotional feeling can be simultaneous with physiological arousal.
James-Lange Theory of Emotion
William James and Carl Lange proposed the James-Lange theory of emotion during the late 19th century, arguing that we become aware of our emotion after we notice our physiological reactions to some external event. James wrote that “we feel sorry because we cry, angry because we strike, afraid because we tremble.” In formal terms, a temporal sequence is posited:
- Event (for example, a frightening situation)
- Appraisal (the cognitive aspect)
- Action (the behavioral aspect, including physiology)
- Emotional feeling (the feeling aspect)
During what phase of sleep do sleepwalking, sleep talking, and night terrors (experiences of intense anxiety which lead people to awaken screaming in terror) typically occur?
Non-REM Sleep (NREM)
Insomnia, Narcolepsy, and Sleep Apnea
Insomnia is a disturbance affecting the ability to fall asleep and/or stay asleep. Narcolepsy is a condition characterized by lack of voluntary control over the onset of sleep. The narcoleptic has sudden, brief episodes of sleep. Sleep apnea is an inability to breathe during sleep, sometimes for more than a minute. People with sleep apnea awaken often during the night in order to breathe.
REM Rebound
When people are specifically deprived of REM sleep, but are allowed to sleep during all other sleep stages, they tend to become irritable during waking states. They also report having trouble concentrating. After people who have been deprived of REM sleep are allowed to sleep without being distrubed, they compensate for the loss of REM sleep by spending more time than usual in REM sleep. This phenomenon is called REM Rebound.
Summary of Sleep
(Narrative)
When you fall asleep, you start in N1 and slowly progress through stages N2, N3, and N4, in order, although loud noises or other intrusions can interrupt the sequence. After ~ one hour of sleep, you begin to cycle back from stage 4 through stages 3, 2, and then REM. The sequence repeats, with each cycle lasting ~ 90 minutes. Early in the night, stages 3 and 4 predominate. Toward morning, REM occupies an increasing percentage of time. The amount of REM depends more on the time of day than on how long you have been asleep. That is, if you go to sleep later than usual, you will still increase your REM at about the same time that you would have ordinarily.
REM and Dreams
Shortly after the discovery of REM, researchers believed it was almost synonymous with dreaming. William Dement and Nethaniel Kleitman (1957) found that people who were awakened during REM reported dreams 80 – 90% of the time. Later research, however, found that people awakened during NREM sleep also sometimes report dreams. REM dreams are more likely than NREM dreams to include visual imagery and complicated plots, but not always. Some people continue to report dreams despite an apparent lack of REM. In short, REM and dreams are not the same thing.
Paradoxical / REM Sleep
Researchers use the term REM sleep for humans but prefer the term paradoxical sleep for nonhuman species that lack eye movements. During REM, the EEG shows irregular, unsynchronized, low-voltage fast waves that indicate increased neuronal activity. However, the postural muscles of the body are more relaxed during REM than in other stages. REM is associated with erection in males and vaginal moistening in females. Heart rate, blood pressure, and breathing rate are more variable in REM than in N2, N3, or N4. In addition to its steady characteristics, REM sleep has intermittent characteristics such as facial twitches and eye movements. Associated with dreaming.
Summary of Sleep
(Brain Waves)
- Awake: Beta and Alpha waves
- Stage 1: Theta waves
- Stage 2: Theta waves
- Stage 3: Delta waves
- Stage 4: Delta waves
- REM: “Similar to Waking”
N1 or Sleep Stage 1
A time of drowsiness or transition from being awake to falling asleep. Brain waves and muscle activity begin slowing down in this stage. People in N1 sleep may experience sudden muscle jerks, preceded by a falling sensation. In N1 sleep, the EEG is dominated by irregular, jagged, low-voltage waves. Brain activity is less than in relaxed wakefulness but higher than in other sleep stages. Theta waves begin to occur––slower in frequency and greater in amplitude than alpha waves.
N2 or Sleep Stage 2
Period of light sleep during which eye movements stop. Spontaneous periods of muscle tone mixed with periods of muscle relaxation. Heart rate slows. In the brain, the most prominent characteristics of N2 sleep are sleep spindles and K-complexes. A sleep spindle consists of 12 – 14Hz waves during a burst that lasts at least half a second. Sleep spindles result from oscillating interactions between cells in the thalamus and cortex. A K-complex is a sharp wave associated with a temporary inhibition of neuronal firing. Characterized by theta waves––slower in frequency and greater in amplitude than alpha waves.
N3 and N4, Stages 3 and 4, or
Slow-Wave Sleep (SWS)
During N3 and N4, heart rate, breathing rate, and brain activity decrease, whereas slow, large-amplitude waves become more common. N3 and N4 differ only in the prevalence of these slow waves. Slow waves indicate that neuronal activity is highly synchronized. The technical term for these slow waves is delta waves.
Brain Waves Characteristic of a Waking State
Beta and alpha waves characterize brain wave activity when we are awake. Beta waves have a high frequency and occur when we are alert or attending to some mental task that requires concentration. Beta waves are unsynchronized. Alpha waves occur when we are awake but relaxing with our eyes closed, and are somewhat slower than beta waves. Alpha waves are also more synchronized than beta waves.
Polysomnography
(PSG)
A multiparametric test used in the study of sleep and as a diagnostic tool in sleep medicine. The test result is called a polysomnogram. The test may include an EEG, eye-movement records, skeletal muscle activation, and heart rhythm (ECG) during sleep.
EEG and Sleep
The EEG records an average of the electrical potentials of the cells and fibers in the brain areas nearest each electrode on the scalp. If half the cells in some area increase their electrical potentials while the other half decrease, they cancel out. The EEG record rises and falls when most cells do the same thing at the same time. You might compare it to a record of the noise in a sports stadium. It shows only slight fluctuations until some event gets everyone yelling at once. The EEG enables brain researchers to monitor brain activity during sleep.
Circadian Rhythm
Our daily cycle of waking and sleeping is regulated by an internally generated circadian rhythm. In humans and other animals, the circadian rhythm approximates a 24-hour cycle; in humans, it is slightly longer than 24 hours: ~ 24 hours + 15 minutes, on average. However, the cycle is recalibrated, or “snapped into place,” by external cues, particularly night and day, called zeitgebers. Still, in experiments where there is no alternation between light and dark, humans and other animals appear to maintain the same roughly 24-hour cycle of waking and sleeping, although with no light / dark alternation, this cycle may be slightly longer or shorter than 24 hours.
Reticular Formation
Neural structure in the brainstem (the midbrain and hindbrain together comprise the brainstem) that keeps our cortex awake and alert. If the reticular formation is disconnected from the cortex (for example, because the connecting fibers are damaged in an accident), the result will be that the person sleeps for most of the day.
Broca’s Aphasia and Wernicke’s Aphasia
Language disorders associated with Broca’s area and Wernicke’s area, respectively. Broca’s aphasia refers to impairments in speaking ability, and is associated with damage to Broca’s area. Wernicke’s aphasia refers to impairments in understanding written and spoken language, and is associated with damage to Wernicke’s area. “Aphasia” comes from the Greek for “not speech.”
Neurocognitive Disorders
Neurocognitive disorders (formerly known as dementias in the DSM-4) are neurological disorders characterized by a loss of intellectual functioning. One example is Alzheimer’s disease, primarily associated with progressive memory loss. Patients with Huntington’s chorea (aka Huntington’s disease) and Parkinson’s disease also present symptoms of neurocognitive disorder. However, cognitive decline progresses at a much slower rate, and the resulting cognitive deficits are less severe than in Alzheimer’s. The motor symptoms in Huntington’s chorea (loss of motor control) and Parkinson’s disease (resting tremors, muscle rigidity) are quite severe, however.
Anterograde Amnesia
Damage or surgical removal of the hippocampus, a brain structure in the limbic system, is associated with anterograde amnesia, or a loss of the ability to create new memories, which leads to a partial or complete inability to recall the recent past.
Agnosia
The Greek roots for agnosia mean “not knowing.” In general, agnosia is an impairment of perceptual recognition. In visual agnosia, there is an impairment in visual recognition. That is, although the person can see an object, let’s say a comb, he or she is unable to know or recognize what it is. Visual perception is registered in the projection area of the visual cortex, whereas visual recognition is processed in nearby association areas. Therefore, damage to these association areas impairs a person’s ability to recognize visual objects without interfering with his or her ability to see.
Apraxia
An impairment in the organization of motor action. The Greek derivation means “inability to act.” Apraxia is characterized by an inability to execute learned (familiar) movements on command, even though the command is understood and there is a willingness to perform the movement. Both the desire and the capacity to move are present but the person simply cannot execute the act. In apraxia, the projection areas in the motor cortex, which send motor impulses down to the muscles, remain more or less intact. The problem seems to arise from damage to the nearby association areas, which organize simple motor movements into predictable voluntary acts.
Alexander Romanovich Luria
(A. R. Luria)
Russian neuropsychologist, often credited as a father of modern neuropsychological assessment. He developed an extensive and original battery of neuropsychological tests during his clinical work with brain-injured victims of World War II, which are still used in various forms.
rCBF
Regional cerebral blood flow. Can be measured with PET or fMRI, for example. When a specific cognitive function, such as listening to music, activates specific areas of the brain, the blood flow to that region increases. In this example, blood flow to the right auditory cortex increases because that is where music is processed in most people’s brains.
Functional Magnetic Resonance Imaging
A modified version of MRI based on hemoglobin (the blood protein that binds oxygen) instead of water. Hemoglobin with oxygen reacts to a magnetic field differently than hemoblobin without oxygen. Researchers set the fMRI scanner to detect the amount of hemoglobin with oxygen. When a brain area becomes more active, two relevant changes occur. First, blood vessels dilate to allow more blood flow to the area. Second, as the brain area uses oxygen, the percentage of hemoglobin with oxygen decreases. An fMRI scan responds to both of these processes.
Magnetic Resonance Imaging
(MRI)
Based on the fact that any atom with an odd-numbered atomic weight, such as hydrogen, has an axis of rotation. An MRI device applies a powerful magnetic field (~ 25,000 times the magnetic field of the Earth) to align all the axes of rotation, and then tilts them with a brief radio frequency. When the radio frequency field is turned off, the atomic nuclei release electromagnetic energy as they relax and return to their original axes. By measuring that energy, MRI devices form an image of the brain––MRI shows anatomical details smaller than a millimeter in diameter. One drawback is that the person must lie motionless in a confining, noisy apparatus.
Computerized Axial Tomography
(CT or CAT)
Dye is injected into the blood (to increase contrast in the image) and then the person’s head is placed into a CT scanner. X-rays are passed through the head and recorded by detectors on the opposite side. The CT scanner is rotated slowly until a measurement has been taken at each angle over 180 degrees. From the measurements, a computer constructs images of the brain. CT scans help detect tumors and other structural abnormalities.
Positron-Emission Tomography
(PET)
PET scans provide a high-resolution image of activity in a living brain by recording the emission of radioactivity from injected chemicals. First, the person receives an injection of glucose or some other chemical containing radioactive atoms. Glucose use increases in the most active brain areas. When a radioactive atom decays, it releases a positron that immediately collides with a nearby electron, emitting 2 gamma rays in exactly opposite directions. The person’s head is surrounded by a set of gamma ray detectors. When two detectors record gamma rays at the same time, they identify a spot halfway between those detectors as the point of origin of the gamma rays. A computer uses this info to determine how many gamma rays came from each spot in the brain and therefore how much of the radioactive chemical is located in each area. PET scans use radioactive chemicals with a short half-life, made in a device called a cyclotron. Because cyclotrons are expensive, PET is available only at research hospitals. Furthermore, PET requires exposure to radioactivity. PET has now been mostly replaced with fMRI.
Electroencephalograph
(EEG)
An apparatus for detecting and recording brain waves. The technique involves placing several electrodes on the surface of the head. Broad patterns of electrical activity can thus be detected and recorded. The machine is called an electroencephalograph. The machine produces an electroencephalogram. Because it is noninvasive, EEG is commonly used with human subjects. Sleep research relies heavily on EEG.
Problem with studying human brain lesions
Human brain lesions are rarely isolated to specific brain structures. When several brain structures are damaged, it becomes difficult to attribute a specific functional impairment to any one brain region.
Studying brain lesions in animals
The advantage of studying brain lesions in animals is that precisely defined brain lesions can be created. Ablation (or extirpation) refers to any surgically induced brain lesion. Researchers can produce lesions by applying heat, cold, or electricity to specific brain regions. The device used to locate brain areas when electrodes (for example) are implanted to make lesions or stimulate nerve cell activity is called a stereoscopic instrument.
Stereoscopic Instrument
Device used to locate brain areas when electrodes (for example) are implanted to make lesions or stimulate nerve cell activity.
Wilder Penfield
With his colleague Herbert Jasper, invented the Montreal Procedure, in which he treated patients with severe epilepsy by destroying nerve cells in the brain where the seizures originated. Before operating, he would stimulate the brain with electrical probes while the patient was conscious on the operating table (under only local anesthesia), and observe their responses. In this way he could more accurately target the areas of the brain responsible, reducing the side-effects of the surgery. This technique also allowed him to create maps of the sensory and motor cortices of the brain (cortical homunculi) showing their connection to the various limbs and organs of the body. These maps are still used today, practically unaltered.
Cortical Homunculus
(plural Homunculi)
A distorted representation of the human body, based on a neurological “map” of the areas and proportions of the human brain dedicated to processing motor functions, or sensory functions, for different parts of the body. The word “homunculus” is Latin for “little man,” and was a term used in alchemy and folklore long before it appeared in scientific literature.
Using eletrodes in lab animals to study deeper regions of the brain (deeper, that is, than the cortical homunculi)
Depending on where electrodes are implanted, researchers have found that brief bursts of electrical current can elicit sleep, sexual arousal, rage, or terror. Once the electrode is turned off, these behaviors cease.
David Hubel and Torsten Wiesel
Used single-cell recording, in which individual neurons are recorded by inserting ultrasensitive microelectrodes into single brain cells. They applied this procedure to the visual cortex of cats, and their results formed a neural basis for feature detection theory, which suggests that certain cells in the cortex are maximally sensitive to certain features of stimuli. They distinguished 3 different types of cells: simple, complex, and hypercomplex.
Neuropsychology
Neuropsychology is the term used to refer to the study of functions and behaviors associated with specific regions of the brain. It is mostly applied in research settings, where researchers attempt to associate very specific areas in the brain to behavior, and clinical settings where patients are treated for brain lesions. Neuropsychology has its own experimental methodology and technology.
Testosterone
Produced in the testes. Stimulates production of sperm, maturation of male genitalia, and growth of facial / pubic hair.
Hormones produced by the ovaries
The ovaries produce estrogen, which stimulates female sex characteristics, and in the menstrual cycle is associated with the maturation and release of the egg or ovum from the ovary. The ovaries also produce progesterone, which prepares the uterus for implantation of the embryo.
Adrenal Medulla
Inner part of the adrenal glands. Produces adrenaline (epinephrine), which increases sugar output of the liver; also increases heart rate; crucial in “fight or flight” response.
Thyroid
Affects metabolism rate, growth, and development.
Female Reproductive Cycle
(The female reproductive cycle is called the menstrual cycle in humans and primates, and the estrus cycle in other mammals.) First, the pituitary secretes a hormone called follicle-stimulating hormone (FSH), which stimulates the growth of an ovarian follicle, which is a small-protective sphere surrounding the egg or ovum. Luteinizing hormone (LH), also produced by the pituitary, is associated with ovulation, which is the release of the egg from one of the ovaries. At various stages during this cycle the ovaries manufacture and secrete two hormones: estrogen and progesterone. Increasing levels of estrogen are associated with the maturation and release of the egg or ovum from the ovary. The function of progesterone is to prepare the uterus for implantation of the fertilized egg. If an ovum is fertilized by a sperm cell, the ovum begins to divide and soon attaches itself to the uterine wall. If the ovum is not fertilized, estrogen and progesterone levels decrease, at which point menstruation begins.
Sexual Development
Hormones that are regulated by the hypothalamus and anterior pituitary play a role in initiating, maintaining, and halting development of primary and secondary sex characteristics. There are two kinds of sex chromosomes: X and Y. At conception, the embryo always inherits an X chromosome from the mother but may receive either an X or a Y chromosome from the father. When a fetus inherits two X chromosomes, it is genetically female; when it inherits an X and a Y, it is genetically male. The genetic sex of a child is determined upon fertilization; however, the development of physical characteristics of the fetus occurs later. Male development, for example, requires the presence of hormones called androgens during critical stages of development. The most important androgen to remember is testosterone. Just after conception, the Y chromosome initiates production of androgens. Normal development of the testes and penis then proceeds. During puberty, the pituitary gland produces and releases gonadotropic hormones, also called gonadotropins. These chemical messengers activate a dramatic increase in production of hormones by the testes or ovaries. In males, they stimulate the testes to produce sperm. They also stimulate a surge in testosterone which leads to facial hair and deepening voice. In females, they stimulate the ovaries to secrete estrogen which accelerates development of female genitalia and has a role in the menstrual cycle.
The Default is Female
If a genetically male fetus does not produce or cannot use androgens, development will follow the female pattern (regardless of chromosomal genetic sex). For example, androgen-insensitivity syndrome. Anatomic development of a female fetus does not require female hormones, but merely the absence of androgens.
Primary vs. Secondary Sex Characteristics
Primary sex characteristics are present at birth: sex organs, or gonads (ovaries and testes), and external genitalia. In contrast, secondary sex characteristics do not appear until puberty––for females, enlarged breasts and widened hips; for males, facial hair and a deeper voice.
Glands and Hormones
The endocrine system shares many functions with the hypothalamus. (remember the 4 “Fs”) The hypothalamus works directly with the pituitary gland, the so-called “master gland.” The pituitary gland, located at the base of the brain, is divided into two parts: anterior and posterior. It is the anterior pituitary that is the master since it releases hormones that regulate activities of endocrine glands. However, the hypothalamus controls the anterior pituitary. The pituitary secretes various hormones into the bloodstream that travel to other endocrine glands located elsewhere in the body to activate them. Once activated by the pituitary, a given endocrine gland manufactures and secretes its own characteristic hormone into the bloodstream. This chemical messenger then signals a specific internal organ like the heart or liver to change its functioning.
Hypothalamus
Structure within the forebrain, subdivided into lateral, ventromedial, and anterior regions. Serves homeostatic functions (receptors in the hypothalamus regulate metabolism, temperature, and water balance––osmoregulation is performed by osmoreceptors in the hypothalamus). The hypothalamus is important in drive behaviors, including hunger, thirst, and sexual behavior. Crucial for the fight or flight response. Also involved in sleep. 4 Fs: feeding, fighting, flighting, fucking. The hypothalamus is the link between the endocrine and nervous systems. It produces releasing and inhibiting hormones, which stop and start the production of other hormones throughout the body. (In general, the hypothalamus is involved in emotional experience during high-arousal states.)
Medulla Oblongata
Part of the hindbrain. Often called simply the “medulla.” The lowest portion of the brainstem and the point where the spinal cord connects to the brainstem. It contains a number of important tracts and nuclei that are necessary for maintaining vital functions like heart rate, blood pressure and respiration.
Reticular Formation
Extends from the hindbrain into the midbrain and is composed of a number of interconnected nuclei. Regulates arousal, alertness, and attention (sleeping and waking). Anasthetics cause unconsciousness in part by depressing activity of the reticular formation.
Thalamus
Structure within the forebrain that serves as an important relay station for incoming sensory information, including all senses except smell. After receiving incoming sensory impulses, the thalamus sorts them, then transmits them to the appopriate areas of the cerebral cortex.
Cerebral Cortex
Part of the forebrain. The outer layer of the cerebrum, and the most recent evolutionary development of the human brain. In humans, the cerebral cortex is associated with everything from language processing to problem solving, impulse control, and long-term planning. The cerebral cortex is composed of gray matter (outside) and white matter (inside).
Ganglia vs. Nuclei
Ganglia are clusters of nerve cell bodies in the PNS, whereas nuclei are clusters of nerve cell bodies in the CNS.
Walter Cannon
(1871 – 1945) Performed pioneering work on the autonomic nervous sytem. Coined the term “fight or flight response”; expanded on Claude Bernard’s concept of homeostasis; and with Philip Bard, proposed the Cannon-Bard theory of emotions.
Somatic Nervous System
Consists of sensory and motor neurons distributed throughout the skin and muscles. Sensory neurons transmit information through afferent fibers. Motor impulses, in contrast, travel along efferent fibers.
Lateral Hypothalamus (LH)
The hunger center: has special detectors that detect when your body needs more food or fluids. When the LH is destroyed in lab rats, they refuse to eat or drink and would die if not force-fed through tubes. This disorder is called aphagia. The root word phagos means “eating.” The same root word appears in esophagus, the tube leading from mouth to stomach. To remember the association between “lateral hypothalamus” and “aphagia,” think _L_acking _H_unger, or LH, which are also the initials for _L_ateral _H_ypothalamus. Additionally, the LH plays a role in rage and fighting behaviors.
Ventromedial Hypothalamus
(VMH)
The satiety center. The VMH tells you when you’ve had enough to eat. Brain lesions to the VMH usually lead to obesity. A name for this disorder is hyperphagia, or excessive eating. To remember the connection between the “ventromedial hypothalamus” and “hyperphagia,” remember that hyperphagia refers to being Very Hungry (the initials VH can also stand for Ventromedial Hypothalamus).
