Chapter 12 Flashcards
Does physical pain and social pain have a common neuroanatomical basis?
Yes. The insula, dorsal anterior cingulate cortex (daCC), somatosensory thalamus and secondary somatosensory cortex (SII)
Why does this prey-killing circuit become active when a cat does not need food?
One explanation is that, to secure survival, the activity of circuits like the prey-killing circuit is in some way rewarding—it makes the cat feel good. As a result, the cat will engage often in the pleasure-producing behavior. This helps to guarantee that the cat will usually not go hungry.
Why was Roger so hungry?
Neurological testing revealed that a tumor had invaded Roger’s hypothalamus at the base of his brain. He was indeed hungry all the time and in all likelihood could consume more than 20,000 calories a day if allowed to do so.
Who first proposed the idea that behaviors such as prey killing are rewarding?
Steve Glickman and Bernard Schiff
What did Butler and Harlow discover?
Monkeys in these conditions spent a lot of time opening the door and viewing whatever was on display, such as toy trains circling a track. The monkeys were even willing to perform various tasks just for an opportunity to look through the door. The longer they were deprived of a chance to look, the more time they spent looking when finally given the opportunity.
What are innate releasing mechanisms?
activators for inborn adaptive responses that aid an animal’s survival. IRMs help an animal to feed, reproduce, and escape predators.
What was Kolb and Nonneman’s experiment?
The researchers allowed a litter of 6-week-old kittens to play in a room and become familiar with it. After this adjustment period, they introduced a two-dimensional image of an adult cat in a Halloween posture, as shown in Figure 12-2A, and a “Picasso” control version, as shown in Figure 12-2B. The kittens responded to the Halloween cat image with raised fur, arched backs, and bared teeth, all signs of being threatened by the image of the adult cat. Some even hissed at the model.
What were their results?
Some sort of template of this posture must be prewired in the kitten brain. Seeing the model that matched this preexisting template automatically triggered a threat response. This innate trigger is an IRM.
How do we know the IRM concept applies to humans?
Through the results of Field ‘s study in 1982
Describe Field’s study
She asked an adult to display to young infants various exaggerated facial expressions, such as happiness, sadness, and surprise.
What were her results?
As Figure 12-3 shows, the babies responded with very much the same expressions the adults displayed. These newborns were too young to be imitating the adult faces intentionally. Rather, babies must innately match these facial expressions to internal templates, in turn triggering some prewired program to reproduce the expressions in their own faces. Such an IRM would have adaptive value if these facial expressions serve as important social signals for humans.
What were the responses of congenitally blind children?
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.
Give an example of how IRMs can be modified by experience
Our cat Hunter’s stalking skills were not inherited fully developed at birth but rather matured functionally as she grew older.
How can the IRM concept relate to the Darwinian concept of the nervous system?
Natural selection favors behaviors that prove adaptive for an organism, and these behaviors are passed on to future generations. Because behavior patterns are produced by the activity of neurons in the brain, the natural selection of specific behaviors is really the selection of particular brain circuits.
What is evolutionary psychology?
the field that applies principles of natural selection to explanations of human behaviour
How do evolutionary psychologists explain homicide?
Evolutionary psychologists assume that any behavior, including homicide, occurs because natural selection has favored the neural circuits that produce it. When two men fight a duel, one common sense explanation might be that they are fighting over grievance. Men who fought and won duels passed on their genes to future generations. Through time, therefore, the traits associated with successful dueling—strength, aggression, agility—became more prevalent among humans, as did dueling.
How do Daly and Wilson (1988) extend this analysis of homicide?
In their view, homicide may endure in our society despite its severe punishment because it is related to behaviors that were adaptive in the human past.
What were Buss’ (2014) conclusions?
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.
What is the current belief about where the preference for older men and younger women and vice versa come from?
These preferences are a product of natural selection in a Stone Age environment, when women and men would have faced different daily problems and thus would have developed separate adaptations related to mating.
What are the pros and cons of evolutionary psychology?
Pro: evolutionary psychologists can generate intriguing hypotheses about how natural selection might have shaped the brain and behavior.
Con: Evolutionary theory cannot account for all human behavior, perhaps not even homicide or mate selection
What did BF Skinner believe?
behaviors are selected by environmental factors.
How do reinforcers influence behavior?
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.
Describe Skinner’s experiment
The power of experience to shape behavior by pairing stimuli and rewards is typified by one of Skinner’s experiments. 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.
How did Skinner explain a phobia of planes?
Understanding a person’s reinforcement history could account for various phobias. Someone who once was terrified by a turbulent plane ride thereafter avoids air travel and manifests a phobia of flying. The avoidance of flying is rewarding because it lowers the person’s anxiety level, which then maintains the phobic behavior.
Describe Skinner’s stance on free will
free will is an illusion because behavior is controlled not by the organism but rather by the environment, through experience.
What does the experience do?
Increasing evidence suggests that epigenetic changes regulate changes in memory circuits.
What is the evidence that 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. Why not? Although the same simple pecking behavior is being rewarded, apparently 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
What were Koelling and Garcia’s observation?
Garcia observed that farmers in the western United States are constantly shooting at coyotes for attacking lambs, yet despite the painful consequences, the coyotes never seem to learn to stop killing lambs in favor of safer prey. The reason, Garcia speculated, is that a coyote’s brain is not prewired to make this kind of association.
What did Garcia do to teach the wolves not to eat sheep?
he connection between eating something that makes one sick and avoiding that food in the future. Garcia gave the coyotes a poisoned lamb carcass, which sickened but did not kill them. With only one pairing of lamb and illness, most coyotes learned not to eat sheep for the rest of their lives.
What is learned taste aversion?
learned taste aversion is acquired even when the food eaten is in fact unrelated to the later illness. As long as the taste and the nausea are paired in time, the brain is prewired to connect them.
How does this associative learning make sense?
Having a brain that is prepared to make a connection between a novel taste and subsequent illness helps an animal avoid poisonous foods and so aids in its survival. A curious aspect of taste aversion learning is that we are unaware of having formed the association until we encounter the taste and/or smell again.
How does preparedness relate to emotional behaviour?
Preparedness can help account for some complex behaviors. For example, 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. The extent to which we might extend this idea to explain such human behaviors as bigotry and racism is an interesting topic to ponder.
Why is odour important to mammals?
Mammals identify group members by odor; mark their territory with urine and other odorants; identify favorite and forbidden foods by taste; and form associations among odors, tastes, and emotional events.
What is the receptor surface for olfaction and how does it work?
- olfactory epithelium
- The epithelium is composed of receptor cells and support cells. Each receptor cell sends a process ending in 10 to 20 cilia into a mucous layer, the olfactory mucosa. Chemicals in the air we breathe dissolve in the mucosa to interact with the cilia. If an olfactory chemosignal affects the receptors, metabotropic activation of a specific G protein leads to an opening of sodium channels and a change in membrane potential.
How come dogs can smell better than humans?
. 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.
How are we able to smell many different odors despite having a small number of receptor types?
The 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.
What is the olfactory pathway?
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. Mitral cells send their axons from the olfactory bulb to the broad range of forebrain areas. Many olfactory targets, such as the amygdala and pyriform cortex, have no connection through the thalamus, as do other sensory systems. However, a thalamic connection (to the dorsomedial nucleus) does project to the orbitofrontal cortex (OFC), the prefrontal area behind the eye sockets (the orbits)
What are pheromones?
biochemicals released by one animal that act as chemosignals and can affect the physiology or behavior of another animal of the same species.
How does the vomeronasal organ detect pheromones?
the vomeronasal organ, which is made up of a small group of sensory receptors connected by a duct to the nasal passage. The receptor cells in the vomeronasal organ send their axons to the accessory olfactory bulb, which lies adjacent to the main olfactory bulb; this connects primarily with the amygdala and hypothalamus, via which it probably plays a role in reproductive and social behavior.
What is flehman?
When exposed to novel urine from a cat or human, cats raise their upper lip to close off the nasal passages and suck air into the mouth. The air flows through the duct on the roof of the mouth en route to the vomeronasal organ.
What were Olsson et. al’s findings?
The compound delta 4,16-androstadien-3-one (androstadienone), a natural component of human sweat, plays a unique role in communication between humans. There is growing evidence 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 (e.g., Olsson et al., 2006).
How are these social odors perceived?
Hummer et. al, 2017 used fMRI to examine the effect of androstadienone on the brain’s response to emotional images (relative to neutral images) of participants who were exposed to the odor versus no odor. They found increased activity in the right dorsolateral prefrontal and orbital prefrontal regions, especially when the images were positive.
What were Lundstrom et. al’s findings?
Another study provides evidence that 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
What are the functions of the insula?
The insula contains regions related to language, taste perception, and social perception
What types of tastes do humans, rats and dogs like?
Humans and rats like sucrose and saccharin solutions, but dogs reject saccharin, and cats are indifferent to both, inasmuch as they do not detect sweetness at all. The failure of cats to taste sweetness may not be surprising: they are pure carnivores, and nothing that they normally eat is sweet.
What was the result of Bartoshuk’s study?
some perceive certain tastes as very bitter, whereas others are indifferent to them. Presumably, the latter group is more tolerant of Brussel sprouts.
How does genetics influence sensitivity to bitterness
It’s 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. People able to detect minute quantities of PROP find the taste extremely bitter; they are sometimes called supertasters. Those who do not taste PROP as very bitter are nontasters. The advantage of being a supertaster is that many bitter “foods” are poisonous. The disadvantage is that supertasters avoid many nutritious fruits and vegetables, such as grapefruit, that they find too bitter.
How does age influence taste thresholds?
Children are much more responsive to taste than adults and are often intolerant of spicy foods because they have more taste receptors than adults have. It is estimated that by age 20, humans have lost at least 50 percent of their taste receptors. No wonder children and adults have different food preferences.
Where are taste receptors found?
Taste receptors are found in taste buds on the tongue, under the 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.
What are the 5 types of taste receptors?
The four most familiar are sweet, sour, salty, and bitter. The fifth type, called the umami (meaning “savory” in Japanese) receptor, is especially sensitive to glutamate.
Why do gustatory stimuli interact with microvilli?
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).
What is the solitary tract?
Cranial nerves 7, 9, and 10 form the main gustatory nerve, the solitary tract.
Describe the gustatory pathway to the primary somatosensory cortex
Cranial nerves 7, 9, and 10 form the main gustatory nerve, the solitary tract. On entering the brainstem, the tract splits, as illustrated in Figure 12-8. 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 (SI)
Describe the gustatory pathway to the primary gustatory cortex of the insula
Cranial nerves 7, 9, and 10 form the main gustatory nerve, the solitary tract. On entering the brainstem, the tract splits, as illustrated in Figure 12-8. 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 (SI) and the other to the primary gustatory cortex of the insula, a region just rostral to the secondary somatosensory cortex (SII).
What is the gustatory region in the insula responsible for?
Taste
What is the SI responsible for?
Tactile information and possibly our reaction to food’s texture
How do we perceive flavour?
The gustatory cortex sends a projection to the orbital frontal cortex. Neuroimaging studies suggest that the mixture of olfactory and gustatory input in the orbital cortex gives rise to our perception of flavor. It is believed that the insula identifies the nature and intensity of flavors, whereas the orbital frontal cortex evaluates the affective properties of tastes. Ambience, including music and light, also affects this region of orbital cortex, increasing blood flow and so enhancing our experience of flavor.
What are possibly evaluating the pleasantness and strength of flavours?
The second pathway from the gustatory nerve (shown in blue in Figure 12-8) projects via the nucleus of the solitary tract in the brainstem to the hypothalamus and amygdala. Researchers hypothesize that these inputs somehow play a part in eating, possibly evaluating the pleasantness and strength of flavors.
What structure plays a key role in motivation?
The neural circuits that control motivated behavior encompass regions at all levels of the brain, but the critical neural structure in producing motivated behavior is the hypothalamus. The hypothalamus receives projections from all major subdivisions of the nervous system and functions to integrate diverse adaptive behaviors. It is not an individual brain region but rather is composed of smaller neural units devoted to specific functions.
What were Swanson’s findings?
The hypothalamus is an integrative center of a larger “behavioral control column” (or network) controlled by the cerebral hemispheres.
How does the behavioural control column work?
This behavioral column is composed of a rostral brainstem region devoted to social (including reproductive and defensive) behaviors and ingestion (eating and drinking), as well as a more caudal region extending into other brainstem areas related to exploration and foraging behaviors, such as the substantia nigra and ventral tegmentum. These functions are modulated by the cerebral hemispheres through descending pathways from the cerebral cortex, striatum, and pallidum. The hypothalamus acts to organize these cerebral inputs and produce feedback loops that regulate cerebral information to orchestrate homeostasis and motivated behaviors; it also ensures that the cerebral regions are aroused and online when needed. In addition, outputs from the hypothalamus project to the pituitary to control the release of a broad range of hormones.
How does the hypothalamus produce behavior?
To produce behavior, the hypothalamus sends axons to other brainstem circuits—but not all behavior is controlled via the funnel to the hypothalamus. Many other routes to the brainstem and spinal cord bypass the hypothalamus, among them projections from the motor cortex to the brainstem and spinal cord. Thus, it is primarily motivated behaviors that require hypothalamic involvement.
What are regulatory behaviours?
Regulatory behaviors—behaviors motivated by an organism’s survival—are controlled by homeostatic mechanisms.
What is a set point?
Human body temperature is controlled in a somewhat similar manner by a thermostat in the hypothalamus that holds internal temperature at about 37°C, a temperature referred to as a set point. Even slight variations cause us to engage in various behaviors to regain the set point.
What are non regulatory behaviours?
nonregulatory behaviors are neither required to meet the basic survival needs of an animal nor controlled by homeostatic mechanisms (see table). Thus, nonregulatory behaviors include everything else we do—from sexual intercourse to parenting to such curiosity-driven activities as conducting psychology experiments.
What brain structures are active in non regulatory behaviours?
Some certain nonregulatory behaviors, such as sexual intercourse, do involve 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.
How does the hypothalamus maintain 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 cerebral hemispheres. Although it constitutes less than 1 percent of the human brain’s volume, the hypothalamus controls an amazing variety of motivated behaviors, ranging from heart rate to eating and sexual activity.
What is the main function of the hypothalamus?
To control the pituitary gland
What is the MFB?
The lateral hypothalamus, composed both of nuclei and of nerve tracts running up and down the brain, connects the lower brainstem to the forebrain. The principal tract, shown in Figure 12-11, is the medial forebrain bundle (MFB).
What does the MFB do?
The MFB connects brainstem structures with various parts of the limbic system and forms the activating projections that run from the brainstem to the 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.
Why do the hypothalamic nuclei have different and multiple functions?
Each hypothalamic nucleus is anatomically distinct, and most have multiple functions, in part because the cells in each nucleus contain a different mix of peptide neurotransmitters. Each peptide participates in different behaviors
How do peptides made in the hypothalamus influence behaviour?
Neurons in the hypothalamus make peptides (for example, oxytocin and vasopressin) that are transported down their axons to terminals lying in the posterior pituitary. If these neurons become active, they send action potentials to the terminals to release the peptides stored there. But rather than affecting another neuron, as occurs at most synapses, capillaries (tiny blood vessels) in the posterior pituitary’s rich vascular bed pick up these peptides.
The peptides then enter the bloodstream, which carries them to distant targets, where they exert their effects. Vasopressin, for example, affects water resorption by the kidneys, and oxytocin controls both uterine contractions and the ejection of milk by mammary glands in the breasts. Peptides can have multiple functions, depending on where their receptors are. Thus, oxytocin not only controls milk ejection in females but also performs a more general role in several forms of affiliative behavior, including parental care, grooming, and sexual behavior in both men and women
What are releasing hormones and what do they do?
The hypothalamus controls the release of these anterior pituitary hormones by producing releasing hormones, peptides that act to increase or decrease hormone release. Releasing hormones, which are produced by hypothalamic cell bodies, are secreted into capillaries that transport them to the anterior pituitary, as Figure 12-12 shows.
Explain the TSH feedback loop
When the level of, say, thyroid hormone is low, the hypothalamus releases thyroid-stimulating hormone–releasing hormone (TSH-releasing hormone), which stimulates the anterior pituitary to release TSH. TSH then acts on the thyroid gland to secrete more thyroid hormone.
Receptors in the hypothalamus detect the thyroid hormone level. When that level rises, the hypothalamus lessens its secretion of TSH-releasing hormone. This type of system is essentially a form of homeostatic control that works as a feedback mechanism, a system in which a neural or hormonal loop regulates the initiation of neural activity or hormone release
The hypothalamus initiates a cascade of events that culminates in hormone secretion, but it pays attention to how much hormone is released. When a certain level is reached, it stops its hormone-stimulating signals. Thus, the feedback mechanism in the hypothalamus maintains a fairly constant circulating level of certain hormones.
