PSY 435 unit 9 full

learned taste aversion

Acquired association between a specific taste or odor and illness; leads to an aversion to foods that have the taste or odor.

feeding system of the fly

After the fly samples the surface using taste buds on its feet, it takes in food through the proboscis and passes it through the esophagus to the gut. Stretch receptors at the gut entrance determine when the esophagus is full. The recurrent nerve alerts the brain to signal cessation of eating.

Amygdala: basics

Almond shaped collection of nuclei in the limbic system; plays a role in emotional and species typical behaviors. consists of three principal subdivisions, the corticomedial area, the basolateral area, and the central area. Like the hypothalamus, the amygdala receives inputs from all sensory systems. But in contrast with the hypothalamic neurons, more complex stimuli are necessary to excite amygdalar neurons.

environment does not always change the brain

A case in point can be seen again in pigeons. A pigeon in a Skinner box can quickly learn to peck a disc to receive a bit of food, but it cannot learn to peck a disc to escape from a mild electric shock to its feet. Although the same simple pecking behavior is being rewarded, the pigeon's brain is not prewired for this second kind of association. The bird is prepared genetically to make the first association, for food, but not prepared for the second. This makes adaptive sense as typically, it flies away from noxious situations.

skinners pigeon experiment

A pigeon is placed in a box that has a small disc on one wall (the stimulus). If the pigeon pecks at the disc (the response), a food tray opens, and the pigeon can feed (the reinforcement or reward). The pigeon quickly learns the association between the stimulus and the response, especially if the disc has a small spot on it. It pecks at the spot and within minutes it has mastered the response needed to receive a reward. Now the response requirement can be made more complex, I.E might be required to turn 360 degrees before pecking the disc to gain the reward. the pigeon might be trained to turn in a clockwise circle if the disc is green, to turn in a counterclockwise circle if the disc is red, and to scratch at the floor if the disc is yellow.

experiential responses

A third control on the hormonal activities of the hypothalamus is the brain's responses to experience: neurons in the hypothalamus undergo structural and biochemical changes just as cells in other brain regions do. In other words, hypothalamic neurons are like neurons elsewhere in the brain in that they can be changed by heavy demands on them. Such changes in hypothalamic neurons can affect hormone output.

B.F skinners argument summarized

( operant conditioning) Certain events function as rewards, or reinforcers. When a reinforcing event follows a particular response, similar responses are more likely to occur. Skinner argued that reinforcement can be manipulated to encourage the display of complex behaviors.

innate realsisng mechanism displyed in cat experiment-

(A) Displaying the Halloween cat image stimulates defensive responses in cats—raised fur, arched backs, and bared teeth. This behavior appears at about 6 weeks of age in kittens who have never seen such a posture before. (B) The scrambled "Picasso cat" evokes no response at all.

organization of the limbic system

(A) In this contemporary conception of the limbic system, an interconnected network of structures—the Papez circuit— controls emotional expression. (B) A schematic representation, coded to brain areas shown in part A by color, charts the limbic system's major connections. (c) A reminder that parts A and B can be conceptualized as part of a funnel rim of outputs that, through the hypothalamus, produce emotional and motivated behavior. LOOK AT ROUTES OF INFO TRANSFER

Nuclei and Regions of the hypothalamus

(A) Medial view shows the relation between the hypothalamic nuclei and the rest of the brain. (B) Frontal view shows the relative positions of the hypothalamus, thalamus, and—in the midline between the left and right hemispheres—the third ventricle. Note the three principal hypothalamic

- hypothalamic controls and feedback loop-

(A) Releasing hormones from the hypothalamus stimulate the anterior pituitary to release hormones. The pituitary hormones stimulate target organs, such as the thyroid and adrenal glands, to release their hormones. In the feedback loop, those hormones in turn influence the hypothalamus to decrease its secretion of the releasing hormones. (B) In the milk letdown response, oxytocin released from the hypothalamus stimulates the mammary glands to release milk. Milk letdown is enhanced by infant related stimuli and inhibited by maternal anxiety.

innate releasing mechanism-

(IRM) Hypothetical mechanism that detects specific sensory stimuli and directs an organism to take a particular action. activators for inborn adaptive responses that aid an animal's survival. IRMs help an animal to feed, reproduce, and escape predators. are present from birth rather than acquired through experience, The term releasing indicates that IRMs act as triggers for behaviors set in motion by internal programs.

medial forebrain bundle

(MFB) Tract that connects brainstem structures with various parts of the limbic system; forms the activating projections that run from the brainstem to basal ganglia and frontal cortex. Fibers that ascend from the dopamine and noradrenaline containing cells of the lower brainstem form a significant part of the MFB. The dopamine containing MFB fibers contribute to the control of many motivated behaviors, including eating and sex. They also contribute to pathological behaviors, such as addiction and impulsivity.

orbitofrontal cortex

(OFc) Prefrontal cortex behind the eye sockets (the orbits); receives projections from the dorsomedial nucleus of the thalamus; central to a variety of emotional and social behaviors, including eating; also called orbital frontal cortex.

Klüver-Bucy syndrome: principle symptoms-

- 1. Tameness and loss of fear - 2. Indiscriminate dietary behavior (eating many types of formerly rejected foods) - 3. Greatly increased autoerotic, homosexual, and heterosexual activity with inappropriate object choice (e.g., the sexual mounting of chairs) - 4. Tendency to attend to and react to every visual stimulus - 5. Tendency to examine all objects by mouth - 6. Visual agnosia, an inability to recognize objects or drawings of objects . Visual agnosia results from damage to the ventral visual stream in the temporal lobe, but the other symptoms are related to the amygdalectomy.

- Gustatory pathways: basics-

- Cranial nerves 7, 9, and 10 form the main gustatory nerve, the solitary tract. On entering the brainstem, the tract splits, - One route (traced in red) travels through the posterior medulla to the ventroposterior medial nucleus of the thalamus. This nucleus in turn sends out two pathways, one to the primary somatosensory cortex (S1) and the other to the primary gustatory cortex of the insula, a region just rostral to the secondary somatosensory cortex (S2).

- Donald Hebb sensory deprivation experiment set up-

- Each student lay on a bed in a small, soundproofed room with ears enveloped by a hollowed-out pillow that muffled the monotonous hums of a nearby fan and air conditioner. - Cardboard tubes covered the hands and arms, cutting off the sense of touch, and a translucent visor covered the eyes, blurring the visual world. - The participants were given food and access to bathroom facilities on request. Otherwise, they were asked simply to enjoy the peace and quiet. For doing so, they would receive $20 per day ( a lot back in this time)

- the amygdala and emotion-

- The amygdala's role in Klüver-Bucy syndrome points to its central role in emotion. So does its electrical stimulation, which produces an autonomic response (such as increased blood pressure and arousal) as well as a feeling of fear. Fear produced by the brain in the absence of an obvious threat may seem odd, but fear is basic to species' survival.

David Buss study of mate selection

- examined patterns of mate selection across thousands of participants from 37 cultures, seeking to identify factors beyond culture that influence mate selection. His conclusions after nearly 30 years of study are that women around the world value dependability, stability, education, and intelligence in a long-term mate. Men, however, value good looks, health, and a desire for home and children more than women do. Older men and younger women are most likely to exhibit the mutually desired set of traits, which leads to a universal tendency for age differences between mates.

olfaction: basics-

- is the most puzzling sensory system. while we can discriminate thousands of odors, we have trouble finding words to describe them, we lack a vocabulary for olfactory perceptions.

overlapping of social rejection and physical pain

- there is a great similarity in brain activity between social rejection and feeling physical pain. - results imaged by Kross and colleagues suggest that the brain systems underlying emotional reactions to social rejection may have developed by co-opting brain circuits that support the affective component of physical pain. - do note though that the overlapping activity in brain regions does not rule out unique neural components of emotional experiences. Certainly our subjective experiences are unique . - Another insight from the Kross study is that normalizing the activity of these brain regions probably provides a basis for both physical and mental restorative processes. Seeing the similarity in brain activation during social pain and physical pain helps us understand why social support can reduce physical pain, much as it soothes emotional pain.

psychosurgery

Any neurosurgical technique intended to alter behavior.

prefrontal connections

At left, the PFC receives inputs (red arrows) and sends outputs (blue arrows) to the areas charted on the right.

the only certain formula for weight loss

At present, the only certain formula for weight loss appears to include (1) a permanent switch to a diet reduced in calories and fat and (2) increased ingestion of high fiber foods (e.g., beans, whole grains, greens) combined with (3) increased physical activity. The results of the Mozaffarian study suggest cutting back on foods and beverages with high sugar content as well.

regulatory behavior

Behavior motivated to meet the animal's survival needs. survival—are controlled by homeostatic mechanisms. These neural circuits might induce an involuntary response such as shivering or a seemingly voluntary behavior such as moving closer to a heat source. Similar mechanisms control many other homeostatic processes, including the amount of water in the body, the balance of dietary nutrients, and the blood sugar level.

motivation

Behavior that seems purposeful and goal-directed. Like emotion, motivated behavior is both inferred and subjective, and it can occur without awareness or intent. It includes both regulatory behaviors, such as eating, which are essential for survival, and nonregulatory behaviors, such as curiosity, which are not required to meet an animal's basic needs.

nonregulatory behavior: basics

Behavior unnecessary to the animal's basic survival needs. include everything else that one dose, including sexual intercourse to parenting to such curiosity driven activities as conducting psychology experiments.

Klüver-Bucy syndrome: basics

Behavioral syndrome, characterized especially by hypersexuality, that results from bilateral injury to the temporal lobe.

emotion

Cognitive interpretation of subjective feelings, such as anger, fear, sadness, jealousy, embarrassment, joy. These feelings can operate outside our immediate awareness.

summary of Damasio's findings

Damasio's somatic marker hypothesis proposes how emotions are normally linked to a person's thoughts, decisions, and actions. In a typical emotional state, certain brain regions send messages to many other brain areas and to most of the rest of the body through hormones and the ANS. These messages produce a global change in the organism's state, and the altered state influences behavior, often unconsciously.

evolutionary psychology

Discipline that seeks to apply principles of natural selection to understand the causes of human behavior.

Dopaminergic input: basics

Dopaminergic input is important for regulating how prefrontal neurons react to stimuli, including emotional ones. Abnormalities in this dopaminergic projection may account for some disorders, including schizophrenia, in which people evince little emotional reaction to typically arousing stimuli.

the limbic lobe

Encircling the brainstem, the limbic lobe as described by Broca consists of the cingulate gyrus and hippocampal formation (the hippocampus and parahippocampal cortex), the amygdala, the mammillothalamic tract, and the anterior thalamus.

anorexia nervosa

Exaggerated concern with being overweight that leads to inadequate food intake and often excessive exercising; can lead to severe weight loss and even starvation. an eating disorder with a huge cognitive component: self image. A person's body image is highly distorted in anorexia. This misperception leads to an exaggerated concern with being overweight. That concern spirals to excessive dieting, compulsive exercising, and severe, potentially life threatening weight loss. Anorexia is especially prevalent among adolescent girls.

obesity

Excessive accumulation of body fat.

sensory deprivation

Experimental setup in which a participant is allowed only restricted sensory input; participants generally have a low tolerance for deprivation and may even hallucinate.

prefrontal cortex: basics

Extensive frontal lobe area anterior to the motor and premotor cortex; key to controlling executive functions such as planning. Its three primary areas are the dorsolateral region; the orbitofrontal cortex (OFC), ventromedial PFC. The anterior cingulate cortex (ACC) is closely associated with the PFC, although not strictly part of it.

Innate Releasing Mechanism in Humans-

Facial expressions made by young infants in response to expressions made by the . Evidence for a prewired motor program related to facial expressions also comes from study of congenitally blind children, who spontaneously produce the very same facial expressions that sighted people do, even though they have never seen them in others. diif cultures find diff stimuli stimulating

phobia

Fear of a clearly defined object or situation.

hippocampus

From the Greek word for seahorse; part of the limbic system, distinctive cortical structure lying in the medial temporal lobe; participates in species specific behaviors, memory, and spatial navigation and is vulnerable to the effects of stress.

the digestive system and control of eating

Glucose is the body's primary fuel and virtually the only energy source for the brain. Because the brain requires glucose even when the digestive tract is empty, the liver acts as a short term reservoir of glycogen, a starch that acts as an inert form of glucose. When blood sugar levels fall, as when we are sleeping, detector cells tell the liver to convert glycogen into glucose for release into the bloodstream. Feedback mechanisms provide such information. When food reaches the intestines, it interacts with receptors in the ENS to trigger the release of at least 10 different peptide hormones, including cholecystokinin (CCK), glucagonlike peptide 1 (GLP 1), and peptide YY (PYY). Each, by virtue of its release as food, is absorbed and acts as a satiation or satiety signal that inhibits food intake.

neural control

Hormonal activities of the hypothalamus necessitate regulation by other brain structures, such as the limbic system and the frontal lobes. excitatory and inhibitory influences exerted by cognitive activity imply that the cortex can influence neurons in the periventricular region. It is likely that projections from the frontal lobes to the hypothalamus perform this role.

variation of epithelial receptor surface

In humans, this area is estimated to range from 2 to 4 square centimeters; in dogs, about 18 square centimeters; and in cats, about 21 square centimeters.

reinforcer

In operant conditioning, any event that strengthens the behavior it follows.

funneling signals

In this model, many inputs from the frontal lobes and limbic system funnel through the hypothalamus, which sends its axons to control brainstem circuits that produce motivated behaviors.

transorbital Leukotomy-

In this procedure, a leukotome is inserted through the bone of the eye socket to disconnect the orbitofrontal cortex from the rest of the brain.

Androgens and behavior

Male hormone related to level of sexual interest. Unusually high androgen levels are related to ultrahigh sexual interest; abnormally low androgen levels are linked to low sexual interest or perhaps no interest at all. The brain circuits are more difficult to activate in the absence of androgens

Donald Hebb sensory deprivation experiment results

Most were content for perhaps 4 to 8 hours; then they became increasingly distressed. They craved stimulation of almost any kind. In one version of the experiment, the participants could listen, on request, to a talk for 6-year-old children on the dangers of alcohol. Some of them asked to hear it 20 times a day. Few lasted more than 24 hours in these conditions.

pheromone: basics

Odorant biochemical released by one animal that acts as a chemosignal and can affect the physiology or behavior of another animal. of the same species. affect more the sex behavior, A human chemosignal, androstadienone, has been shown to alter glucose utilization in the neocortex.appears to affect cortical processes even though that signal was not consciously detected.

olfactory pathways

Olfactory receptor cells project to the olfactory bulb, ending in ball like tufts of dendrites the glomeruli where they form synapses with the dendrites of mitral cells. Many olfactory targets, such as the amygdala and pyriform cortex, have no connection through the thalamus, as do other sensory systems. a thalamic connection (to the dorsomedial nucleus) does project to the orbitofrontal cortex

supertasters

People able to detect minute quantities of PROP find the taste extremely bitter

- releasing hormone-

Peptide released by the hypothalamus that increases or decreases hormone release from the anterior pituitary. peptides that act to increase or decrease hormone release.

generalized anxiety disorder

Persistently high levels of anxiety often accompanied by maladaptive behaviors to reduce anxiety; thought to be caused by chronic stress.

preparedness: basics

Predisposition to respond to certain stimuli differently from other stimuli. can help account for some complex behaviors.

homeostatic mechanism

Process that maintains critical body functions within a narrow, fixed range. The limbic and frontal regions project to the hypothalamus, which houses many basic neural circuits for controlling these behaviors.

somatic marker hypothesis

Proposal that marker signals arising from emotions and feelings act to guide behavior and decision making, usually in an unconscious process. Damasio proposed that emotions are responses induced by either internal or external stimuli not normally attended to consciously.

panic disorder

Recurrent attacks of intense terror that come on without warning and without any apparent relation to external circumstances.

PROP

Sensitivity to bitterness is related to genetic differences in the ability to detect a specific bitter chemical (6 n propylthiouracil, or PROP). PROP bitterness associates with allelic variation in the taste receptor gene TAS2R38.

nonregulatory behavior: factors

Some nonregulatory behaviors, such as sexual intercourse, entail the hypothalamus, but most of them probably do not. Rather, such behaviors entail a variety of forebrain structures, especially the frontal lobes. Presumably, as the forebrain evolved and enlarged, so did our range of nonregulatory behaviors. Most nonregulatory behaviors are strongly influenced by external stimuli. As a result, sensory systems must play some role in controlling them.

- medial forebrain bundle

The activating projections that run from the brainstem to the basal ganglia and frontal cortex are major components of the MFB, a primary pathway for fibers connecting various parts of the limbic system with the brainstem.

- Hypothalamus and pituitary gland-

The anterior pituitary is connected to the hypothalamus by a system of blood vessels that carry hormones from the hypothalamus to the pituitary. The posterior pituitary receives input from axons of hypothalamic neurons. Both regions respond to hypothalamic input by producing hormones that travel in the bloodstream to stimulate target organs.

Gustatory pathways: detailed

The gustatory region in the insula is dedicated to taste, whereas S1 is also responsive to tactile information and is probably responsible both for localizing tastes on the tongue and for our reactions to a food's texture. The gustatory cortex sends a projection to the orbital cortex in a region near the input from the olfactory cortex. Neuroimaging studies suggest that the mixture of olfactory and gustatory input in the orbital cortex gives rise to our perception of flavor.

basics of hypothalamic role in homeostasis

The hypothalamus maintains homeostasis by acting on both the endocrine system and the autonomic nervous system (ANS) to regulate our internal environment. The hypothalamus also influences the behaviors selected by the rest of the brain, especially by the limbic system. Although it constitutes less than 1 percent of the human brain's volume,

neural circuits and emotion

The neural circuits that control behavior encompass regions at all levels of the brain, but the critical neural structures in emotional and motivated behavior are the hypothalamus and associated pituitary gland, the limbic system, and the frontal lobes. The expression of emotions includes physiological changes: in heart rate, blood pressure, and hormone secretions. It also includes motor responses, especially movements of the muscles that produce facial expressions

hypothalamic involvement in generating behavior

This function was first demonstrated by studies in which stimulating electrodes were placed in the hypothalamus of various animals, When a small electric current was delivered through a wire electrode, an animal suddenly engaged in some complex behavior—eating, drinking, or digging; displaying fear, attack, predatory, or reproductive behavior. All the behaviors were smooth, well integrated, and indistinguishable from typically occurring ones. Furthermore, all were goal directed. The onset and termination of these behaviors depended entirely on hypothalamic stimulation.

nontasters

Those who do not taste PROP as very bitter . either by genotype or phenotype (for few taste buds), reported greater consumption of vegetables, both bitter and not. with higher numbers of taste buds reported eating about 25% more vegetables than the other groups.

generating behavior rat experiment

When rats receive electrical stimulation to the hypothalamus, they produce goal-directed behaviors. This rat is stimulated to dig when and only when the electricity is on. If the sawdust is removed (not shown), there is no digging.

Major depression

a highly disruptive emotional disorder, is characterized by some or all the following: prolonged feelings of worthlessness and guilt, the disruption of normal eating habits, sleep disturbances, a general slowing of behavior, and frequent thoughts of suicide. A depressed person feels severely despondent for a long time.

executive function of frontal lobe

amygdala is intimately connected to the functioning of the frontal lobes that constitute all cortical tissue anterior to the central sulcus. The motor cortex controls fine movements, especially of the fingers, hands, toes, feet, tongue, and face. The premotor cortex participates in selecting appropriate movement sequences.

basic components of the limbic system

are formed from a primitive three layered cortex known as allocortex, which lies adjacent to the six layered neocortex. In mammals, the allocortex encompasses the cingulate (meaning girdle) gyrus and the hippocampal formation,

pheromone: special

are unique odors because they are detected by a special olfactory receptor system, the vomeronasal organ, which is made up of a small group of sensory receptors connected by a duct to the nasal passage.

Butler and Harlow monkey experiment

came to similar conclusion as Hebb. placed rhesus monkeys in a dimly lit room with a small door that could be opened to view an adjoining room. researchers could vary the stimuli in the adjoining room so that the monkeys could view different objects or animals each time they opened the door. monkeys in this condition spend lot of time looking opening door to see whatever was on display, and were willing to do various tasks for chance to look thorough door. longer deprived, longer chance to look, the more time spent looking when allowed.

the three forms of emotional experience: basics

common characteristic of such experiences includes autonomic responses such as rapid breathing, sweating, and dry mouth. Emotions may also entail strong subjective feelings that we label as anger, fear, or love, among others. Finally, emotions typically entail thoughts or plans related to the experience itself and may take the form of replaying conversations and events in your mind, anticipating what you might say or do under similar circumstances in the future or in planning your married life.

prefrontal cortex: details

contributes to specifying the goals toward which movement should be directed. It controls the processes by which we select movements appropriate to the particular time and context. This selection may be cued by internal information, such as memory and emotion, or it may be made in response to context receive highly processed information from all sensory areas, and many neurons in the prefrontal cortex, like those in the amygdala, are multimodal.

Agenesis of the frontal lobe

despite lacking a right frontal lobe and a half sized left frontal lobe, J. P. seemed completely unaware of his life situation. Even though the rest of his brain was working fairly well—his IQ score was in the normal range, and his language skills were very good—the rest of his brain was unable to compensate for the absence of frontal lobes.

neurology of emotional response

emotional response includes actions on structures in the forebrain and brainstem and ultimately on the ANS. The amygdala has connections to the frontal lobes, so the emotional response can influence the frontal lobes' appraisal. But if the frontal lobes are injured, emotional information is excluded from cognitive processing, so the quality of emotion related appraisals suffers, and the response to the bear might be inappropriate.

Agenesis

failure of a structure to develop

human Olfactory Processing

humans have a surprisingly acute sensitivity to behaviorally significant smells. Several studies show convincingly that people can identify their own odor, the odor of kin versus not kin, and the odor of friends versus strangers with an accuracy well above chance .

the reward explanation of behavior

idea that behavior is controlled by what is found rewarding, that is we do things that we deem as rewarding. this idea of reward circuits control behavior also acts as an explanation as to why well feed house cats continue to kill birds, it activates reward circuits.

rat example of preparedness

if two rats are paired in a small box and exposed to a mild electric shock, they will immediately fight with one another, even though neither was responsible for the shock. Apparently, the rat brain is predisposed to associate injury with nearby objects or other animals.

why a fly wonders

it is not doing so with a purpose or acting by motivation, When a fly wanders about a table, it is not deliberately searching. Rather, it is tasting what it walks on.

important characteristics of hypothalmic generated behavior

more important characteristics of behaviors generated by hypothalamic stimulation are related to (1) survival and (2) reward. Animals apparently find the stimulation of these behaviors pleasant, as suggested by the fact that they willingly expend effort, such as pressing a bar, to trigger the stimulation. from this we can hypothesize that animals eat because eating is rewarding, drink because drinking is rewarding, and mate because mating is rewarding.

pituitary gland

primary function of the hypothalamus is to control this, Endocrine gland attached to the bottom of the hypothalamus; its secretions control the activities of many other endocrine glands; associated with biological rhythms.

donald Hebb's conclusion as to the cause of the experimental results

proposed that the brain has a inherent need for stimulation

Mitral cells

send their axons from the olfactory bulb to the broad range of forebrain areas

Amygdala: details

sends connections primarily to the hypothalamus and the brainstem, where it influences neural activity associated with emotions and species typical behavior. example, when the amygdala of a person with epilepsy is electrically stimulated before brain surgery, the person becomes fearful and anxious. Amygdala stimulation can also induce eating and drinking. The amygdala's role in eating can be seen in patients with amygdalar lesions. Lesions of the amygdala may also give rise to hypersexuality.

how limited number of olfactory receptors allow for the sensation of many different smells

simplest explanation is that any given odorant stimulates a unique pattern of receptors, and the summed activity or pattern of activity produces our perception of a particular odor. Analogously, the visual system enables us to identify several million colors with only three receptor types in the retina: the summed activity of the three cones leads to our richly colored life. A fundamental difference, however, is that the olfactory system is estimated to contain about 400 kinds of receptors compared with 4 (rods plus the cones) in the visual system.

second finding on human olfactory processing

smelling a stranger's odor activates the amygdala and insular cortex, similar to activation observed for fearsome visual stimuli such as masked or fearsome faces. The investigators also asked participants to rate the intensity and pleasantness of odors; they found that strangers' odors were rated as stronger and less pleasant than those of familiar persons.

Whitten effect

synchronization of menstrual cycles the result of women residing together, stimulated by the odor of male urine.

receptors for taste

taste receptors are found in taste buds in tongue, on the soft palate on the roof of the mouth, on the sides of the mouth, and at the back of the mouth on the nasopharynx. Each of the five taste receptor types responds to a different chemical component in food. The four most familiar are sweet, sour, salty, and bitter. The fifth type, called the umami receptor, is especially sensitive to glutamate, a neurotransmitter molecule, and perhaps to nucleotides. Taste receptors are grouped into taste buds, each containing several receptor types, Gustatory stimuli interact with the receptor tips, the microvilli, to open ion channels, leading to changes in membrane potential. At its base, the taste bud contacts the branches of afferent cranial nerve 7 (facial), 9 (glossopharyngeal), or 10 (vagus).

free will

that is the idea that we do what we want and we always have a choice. while many see this as the most obvious explanation of behavior, it is not in fact a likely cause of behavior

first finding on human olfactory processing

the brain analyzes common odors and body odors differently. Although both activate primary olfactory regions, body odors also activate structures not previously believed to participate in olfactory processing, including the posterior cingulate cortex, occipital cortex, and anterior cingulate cortex—regions also activated by visually emotional stimuli. Considered in an evolutionary perspective, the ability to identify human odors probably is uniquely important to safety.

olfactory mucosa

the mucous layer at the end points of olfactory receptors.

olfactory epithelium

the receptor surface for olfaction in the nasal cavity.

- evidence for James Lange theory of emotion evidence 1

the same autonomic responses can accompany different emotions. That is, particular emotions are not tied to unique autonomic changes. This line of evidence leaves room for interpreting what a particular pattern of arousal means, even though particular physiological changes may suggest only a limited range of possibilities. The physiological changes experienced during fear and happiness are unlikely to be confused.

- evidence for James Lange theory of emotion evidence 2

the starting point for emotions comes from people with reduced information about their own autonomic arousal, for example, owing to spinal cord injury. Spinal injury results in a decrease in perceived emotion, and its severity depends on how much sensory input is lost. People with the greatest loss of sensory input, which occurs with injuries at the uppermost end of the spinal cord, also have the greatest loss of emotional intensity. In contrast, people with low spinal injuries retain most of their visceral input and have essentially typical emotional reactions.

James Lange/ physiological changes first perspective of emotion

view is that physiological changes (such as trembling and rapid heartbeat) come first, and the brain then interprets these changes as an emotion. This perspective implies that the brain (most likely the cortex) produces a cognitive response to autonomic information. That response varies with the context in which the autonomic arousal occurs, including the effects on the gut via the ENS.

Damasio study of frontal lobe injuries

was struck by how they could be highly rational in analyzing the world yet still make decidedly irrational social and personal decisions. argued that is that the neural machinery underlying emotion no longer affects the reasoning of people with frontal lobe injury, either consciously or unconsciously. Cut off from critical emotional input, many social and personal decisions suffer.