BUKU Biological Psychology by James W. Kalat

He was twice program chairman for the annual convention of the American Psychological Association, now called the Association for Psychological Science. Release and diffusion of transmitters 53 Activating receptors of the postsynaptic cell 54 Inactivation and reuptake of neurotransmitters 57 Negative feedback from the postsynaptic cell 57 Electrical synapses 59.

Anatomy and Research

Genetics, Evolution, Development,

Deprived experience in one eye 171 Deprived experience in both eyes 171 Uncorrelated stimulation in the two eyes 171 Early exposure to a limited.

Other Sensory Systems 187

Wakefulness and Sleep 257

Sleep and energy conservation 280 Similar to sleep: rest 280 Differences between species in sleep 281 Sleep and memory 283.

Internal

Reproductive Behaviors 321

Emotional

Learning, Memory, and

Cognitive

Psychological Disorders 459

Medications to Combat Alcohol Abuse 465 Medications to Combat Opiate Abuse 465 CONCLUSION: The Psychology and Biology of Substance Abuse 466. No doubt many people in other fields think their subject is the most interesting, but they are wrong.

MindTap for Biological Psychology, 13e

I hope that readers of this book will remember that message even after they have forgotten many of the details. I assume readers have a basic background in psychology and biology and understand such concepts as classical conditioning, reinforcement, vertebrates, mammals, gene, chromosome, cell, and mitochondria.

Changes in This Edition

Unfortunately, it is easy to get so caught up in memorizing facts that one loses sight of the big picture. This organization makes it easy for instructors to assign part of a chapter per day instead of an entire chapter per week.

Preface

Frigatebirds, which are large enough for scientists to monitor them in the air, sometimes sleep in one hemisphere at a time, sometimes sleep briefly in both hemispheres at once, but generally get very little sleep on days when they are at sea . I avoid the term unbelievable, which has become so overused that it has lost its original meaning of "not believable." I also avoid the terms exciting, involved and scandalous, which are also overused and misused.

Instructor Ancillaries

Therefore, the average duration of all early episodes is not comparable to the average delay of subsequent episodes. For example, I wouldn't say, "They offered four different explanations." If they offered four explanations, we can take it for granted that the explanations were different.

Online Instructor’s Manual

Because the mechanisms governing male-female differences vary from one brain area to another, it is common for someone to have a patchwork of male-typical, female-typical, and roughly neutral anatomy in different brain areas. The earlier belief that later episodes of depression become shorter and shorter was based on a methodological artifact.

Cengage Learning Testing, Powered by Cognero®

The text includes up-to-date information about the genetic basis of Parkinson's disease, substance abuse, depression, schizophrenia, and autism. A new hypothesis states that the rapid formation of new neurons in the infant's hippocampus is responsible for both the ease of new learning and the phenomenon of infantile amnesia.

Acknowledgments

Text Reviewers and Contributors

It can mean: Man is strikingly different - he is not the same as any other animal. This also applies to all other animals: each species, even each individual, is unique in this sense.

Overview and Major Issues

But the term is also often used in a more absolute sense: man is so different, so "essentially different" (whatever that means) that the gap between him and the animals cannot possibly be bridged - he is something entirely new.

The Biological Approach to Behavior

To say that consciousness is a fundamental property would mean that we have given up explaining it. After learning as much as possible about the nervous system, perhaps we will understand what consciousness is all about.

The Field of Biological Psychology

As far as we can tell, consciousness only occurs in certain parts of a nervous system, just sometimes - not when you're in a dreamless sleep, and not when you're in a coma. They try to explain mass and charge in terms of the Higgs boson and other principles of the universe.

Biological Explanations of Behavior

To illustrate, consider that people with depression also have less active legs than usual. Suppose we also find that certain genes are less common than average among people with depression.

Three Main Points to Remember from This Book

It deals with the body's machinery—for example, the chemical reactions that allow hormones to influence brain activity and the ways in which brain activity controls muscle contraction. For example, zone-tailed hawks, native to Mexico and the southwestern United States, fly among hawks and hold their wings in the same posture as hawks.

Career Opportunities

Areas of therapy include clinical psychology, counseling psychology, school psychology, medicine, and allied medical practices such as physical therapy. But what if you enter a field on the fringes of neuroscience, such as clinical psychology, school psychology, social work, or physical therapy.

The Use of Animals in Research

How we are similar to chimpanzees and other primates and how we differ from them. For example, investigators insert electrodes into the brains of mice and other animals to determine the relationship between brain activity and behavior.

Degrees of Opposition

What are the “three R’s” in the legal standards for animal research?

The guiding assumption is that the pattern of activity that occurs in your brain when you see something is your perception. This is not to say "your brain physiology controls you" any more than "you control your brain." Rather, your brain is you.

The goal of this introduction was to preview the kinds of questions that biological psychologists hope to answer. The rest of this book explores how far we can go with this guiding assumption.

Summary

Biological psychologists are ambitious and hope to explain as much psychology as possible in terms of brain processes. Physiological: How behavior is related to the physiology of the brain and other organs.

Key Terms

Many careers involve biological psychology, including various areas of research, certain medical specialties, and counseling and psychotherapy. Research on animals today is conducted under legal and ethical controls that seek to minimize animal suffering.

Thought Question

Researchers study animals because the mechanisms are sometimes easier to study in nonhumans, because they are interested in animal behavior for its own sake, because they want to understand the evolution of behavior, and because certain types of experiments are difficult or impossible in humans. are.

End of Introduction Quiz

Of the following, which is a reason to favor the use of animals in biological psychological research aimed at solving human problems. A defense of animal research that recognizes the difficulty of the issue and the competing values ​​at stake.

Suggestions for Further Reading

Explain how the sodium-potassium pump and membrane properties lead to the resting potential of a neuron. Discuss how the movement of sodium and potassium ions produces the action potential and recovery after it.

Nerve Cells

How often do you hunt your own meat and cook it on a fire you made from scratch. Of all the activities necessary for your survival, which – if any – could you do completely on your own, apart from breathing.

Advice: Parts of this and the next chapter assume that you understand the basics of chemistry. To understand the nervous system, we must start by examining the cells that compose it.

Neurons and Glia

Santiago Ramón y Cajal, a Pioneer of Neuroscience

Except for mammalian red blood cells, all animal cells have a nucleus, the structure that contains the chromosomes. A mitochondrion (plural: mitochondria) is the structure that carries out metabolic activities, providing the energy that the cell uses for all activities.

The Structure of a Neuron

The Structures of an Animal Cell

Small branches lead directly from the receptors to the axon, and the soma of the cell is located on a small stalk next to the main trunk. Muscle fibers Figure 1.4 Components Axon. motor neuron of vertebrates The cell body of a motor neuron is located in the spinal cord.

Variations among Neurons

Each sensory neuron is an afferent to the rest of the nervous system, and each motor neuron is an afferent to the rest of the nervous system. Within the nervous system, a particular neuron is the efferent of one structure and the afferent of another structure (see Figure 1.7).

Glia

• What are the widely branching structures of a neuron called?
• Which animal species would have the longest axons?
• Compared to other neurons, would an interneuron’s axon be relatively long, short, or about the same?
• What are the four major structures that compose a neuron?
• Which kind of glia cell wraps around the synaptic terminals of axons?

Oligodendrocytes (OL-i-go-DEN-druh-sites) in the brain and spinal cord and Schwann cells in the periphery of the body build the myelin sheaths that surround and insulate some vertebrate axons. Oligodendrocytes produce myelin sheaths that insulate certain vertebrate axons in the central nervous system; Schwann cells have a similar function in the periphery.

The Blood–Brain Barrier

If a few of them are active at the same time, the astrocyte absorbs some of the chemicals they release. When the inhibition stops, all the axons are primed to respond synchronously again.

Why We Need a Blood–Brain Barrier

For certain other chemicals, the brain uses active transport, a protein-mediated process that uses energy to pump chemicals from the blood into the brain. When the rabies virus escapes the blood-brain barrier, it infects the brain and leads to death.

How the Blood–Brain Barrier Works

The spirochete responsible for syphilis also penetrates the blood-brain barrier, causing long-term and potentially fatal consequences. However, glucose is the only nutrient that crosses the blood-brain barrier in large quantities.

Nourishment of Vertebrate Neurons

• Identify one major advantage and one disadvantage of having a blood–brain barrier
• Which chemicals cross the blood–brain barrier passively?
• Which chemicals cross the blood–brain barrier by active transport?
• In Closing
• End of Module Quiz

If two adjacent spots on your retina—let's call them A and B—send impulses at nearly the same time, an extremely small difference in timing between them will tell your brain whether light traveled from A to B or from B to A . Without some sort of compensation, simultaneous flashes arriving in two places on your retina will reach your brain at different times, and you may perceive movement inaccurately.

The Resting Potential of the Neuron

Opposite electrical charges attract, so the electrical gradient tends to pull sodium into the cell. However, because the sodium channels are closed when the membrane is at rest, almost no sodium flows except what the sodium-potassium pump forces out of the cell.

Why a Resting Potential?

Now let's apply an even stronger current: stimulation above the excitation threshold causes a strong depolarization of the membrane. Any stimulation that exceeds the threshold, no matter how far beyond it, produces a large response as shown, known as an action potential.

The Action Potential

• When the membrane is at rest, are the sodium ions more concentrated inside the cell or outside? Where are the
• When the membrane is at rest, what tends to drive the potassium ions out of the cell? What tends to draw them
• What is the difference between a hyperpolarization and a depolarization?
• What happens if the depolarization does or does not reach the threshold?

Now we apply a current to depolarize the neuron—that is, reduce its polarization toward zero. When the potential reaches a threshold, the membrane opens its sodium channels, allowing sodium ions to flow into the cell.

The Molecular Basis of the Action Potential

The All-or-None Law

Sodium ions pass during the peak of the action potential, while potassium ions pass later in the opposite direction, returning the membrane to its original polarization. During the rise of the action potential, sodium ions move into or out of the cell.

Propagation of the Action Potential

As the membrane reaches the peak of the action potential, it lowers the membrane to its original resting potential. It all follows logically from the facts that voltage-gated sodium and potassium channels open when the membrane is depolarized and that sodium channels close rapidly at the peak of the action potential.

The Myelin Sheath and Saltatory Conduction

What then prevents an action potential near the center of an axon from re-vading the areas it has just passed. How would the action potential be affected in a myelinated axon if the nodes were much closer together.

The Refractory Period

An axon that never had a myelin sheath conducts impulses slowly but steadily, but an axon that has lost its myelin is not the same because it does not have sodium channels where the myelin used to be (Waxman & Ritchie, 1985 ). When the distance er than it could successfully spread v avel fast action potential would tr jump fully from one node to the ne becomes too great, the curr.

Local Neurons

In Closing

The sodium-potassium pump moves sodium ions out of the neuron and potassium ions in. After the peak of the action potential, the membrane returns to its original level of polarization due to the efflux of potassium ions.

End of Module Quiz

Thought Questions

During the rising part of the action potential, which ions move across the membrane and in which direction. After the action potential reaches its peak, the potential across the membrane falls toward its resting level.

Suggestion for Further Reading

Sodium ions move out because their channels are open and the concentration gradient pushes them out. If you had to communicate with someone without sight or sound, what would you do?

Synapses

In the late 19th century, Ramón y Cajal anatomically demonstrated the narrow gap that separates one neuron from another. In 1906, Charles Scott Sherrington demonstrated physiologically that communication between one neuron and the next differs from communication along a single axon.

Properties of Synapses

In fact, the movements were more stable after he separated the spinal cord from the brain. Sherrington observed several properties of reflexes that suggest special processes at junctions between neurons:

Speed of a Reflex and Delayed Transmission at the Synapse

In an intact animal, messages coming down from the brain modify the reflexes, making them stronger in some cases and weaker in others.

Temporal Summation

Spatial Summation

What evidence led Sherrington to conclude that transmission at a synapse is not the same as transmission along an axon?

However, if a neuron receives many incoming axons with synchronized input, spatial summation excites the neuron enough to activate it. That is, it increases the negative charge in the cell, moves it further from the threshold and decreases the probability of an action potential (point 5 in Figure 2.3).

What is the difference between temporal summation and spatial summation?

Today we take the concept of inhibition for granted, but in Sherrington's day the idea was controversial because no one could imagine a mechanism to achieve this. Establishing the idea of ​​inhibition was crucial not only for neuroscience, but also for psychology.

Inhibitory Synapses

Relationship among EPSP, IPSP, and Action Potentials

• What was Sherrington’s evidence for inhibition in the nervous system?
• What ion gates in the membrane open during an EPSP? What gates open during an IPSP?
• Can an inhibitory message flow along an axon?
• In Closing
• End of Module Quiz

They are also listed in alphabetical order with definitions in the book's Subject Index/Dictionary, beginning with When Sherrington measured the reaction time of a reflex (ie, the delay between the stimulus and the response), he found that the response occurred more quickly after a strong stimulus than after a weak one.

The Discovery of Chemical Transmission at Synapses

What was Loewi’s evidence that neurotransmission depends on the release of chemicals?

The Sequence of Chemical Events at a Synapse

Types of Neurotransmitters

Synthesis of Transmitters

It has no therapeutic use, but researchers sometimes use it to study the functions of dopamine.

Storage of Transmitters

Release and Diffusion of Transmitters

Name the three catecholamine neurotransmitters

When the neurotransmitter binds to an ionotropic receptor, it turns the receptor enough to open its central channel, which has a shape that allows a certain type of ion to pass through. Most inhibitory ionotropic synapses use the neurotransmitter GABA (gamma-aminobutyric acid), which opens the chloride gates, enabling chloride ions, with their negative charge, to cross the membrane into the cell faster than usual.

When the action potential reaches the presynaptic termi- nal, which ion must enter the presynaptic terminal to evoke

All these processes allow the nervous system to be incredibly flexible. it can go in or out of the bag. When an action potential reaches the presynaptic terminal, some ion must enter the presynaptic terminal to fire it.

Activating Receptors of the Postsynaptic Cell

Some neurons release two transmitters simultaneously (Tritsch, Ding, & Sabatini, 2012), while some release one first and another slowly later (Borisovska, Bensen, Chong, & Westbrook, 2013). Sometimes a neuron changes transmitters, for example by releasing one transmitter in the summer and another in the winter (Spitzer, 2015).

Ionotropic Effects

When the receptor is at rest, the inside coils together tightly enough to block the passage of sodium. When acetylcholine binds as in Figure 2.15b, the receptor folds outward, widening the sodium channel (Miyazawa, Fujiyoshi, and Unwin, 2003).

Metabotropic Effects and Second Messenger Systems

Neuropeptides

In addition, neuropeptides, unlike other transmitters that are released directly at their receptors, diffuse widely and slowly affect many neurons in their part of the brain. Neuropeptides are important for hunger, thirst, and other long-term changes in behavior and experience.

Variation in Receptors

Because many of them exert their effects by altering gene activity, their effects often last twenty minutes or longer.

Drugs That Act by Binding to Receptors

• How do ionotropic and metabotropic synapses differ in speed and duration of effects?
• What are second messengers, and which type of synapse relies on them?
• How do neuropeptides compare to other transmitters?
• How do LSD, nicotine, and opiate drugs influence behavior?

Subsequently, researchers discovered that opiates attach to specific receptors in the brain (Pert & Snyder, 1973). Methylphenidate and cocaine similarly block dopamine reuptake at the same brain receptors.

Inactivation and Reuptake of Neurotransmitters

• What happens to acetylcholine molecules after they stimu- late a postsynaptic receptor?
• What happens to serotonin and catecholamine molecules after they stimulate a postsynaptic receptor?
• How do amphetamine and cocaine influence synapses?
• Why is methylphenidate generally less disruptive to behavior than cocaine is despite the drugs’ similar mechanisms?

This discovery was important because it indicated that opiates relieve pain by acting on receptors in the brain as well as in the skin. People taking methylphenidate pills experience a gradual increase in the drug's concentration over an hour or two, followed by a slow decline.

Negative Feedback

Soon, researchers discovered that the brain produces its own neuropeptides, now known as endorphins (a contraction of endogenous morphine), which bind to the same receptors as endorphins. When stimulants increase the accumulation of dopamine in the synaptic cleft, COMT breaks down the excess dopamine faster than the presynaptic cell can replace it.

Some cells in the retina emit hydrogen ions (that is, protons) to inhibit further transmission (Wang, Holzhausen, & Kramer, 2014). Cannabinoids, the active chemicals in marijuana, bind to anandamide or 2-AG receptors on presynaptic neurons, indicating, “The cell has received your message.

Electrical Synapses

Hormones

• How do cannabinoids affect neurons?
• Which part of the pituitary—anterior or posterior—is neural tissue, similar to the hypothalamus? Which part is glandular
• In what way is a neuropeptide intermediate between neu- rotransmitters and hormones?
• In Closing
• End of Module Quiz
• GABA 8. What is a second messenger?

The posterior pituitary, which consists of neural tissue, can be considered an extension of the hypothalamus. Which part of the pituitary—anterior or posterior—is neural tissue, similar to the hypothalamus.

Anatomy and Research Methods

The first module introduces key neuroanatomical terms and outlines the general structures of the nervous system. In the second module, we focus on the cerebral cortex, the largest part of the mammalian central nervous system.

Terminology to

Your nervous system includes a large number of neurons and an even larger number of synapses.

Describe the Nervous System

However, when humans evolved upright posture, the position of the head changed relative to the spinal cord. In four-legged animals, the dorsal and ventral axes for the head are parallel to those for the rest of the body.

The Spinal Cord

• What does ventral mean, and what is its opposite?
• What term means toward the midline, and what is its opposite?
• If two structures are both on the left side of the body, they are ______ to each other. If one is on the left and the other is on
• The bulges in the cerebral cortex are called _______. The grooves between them are called ____

Each segment of the spinal cord sends sensory information to the brain and receives motor commands from the brain. If the spinal cord is cut at a certain segment, the brain loses sensation from that segment and below.

The Autonomic Nervous System

Many neurons from the gray matter of the spinal cord send axons to the brain or to other parts of the spinal cord through the white matter, which contains myelinated axons. The brain also loses motor control over all parts of the body served by that segment and the lower ones.

The Hindbrain

Motor nerves leave from which side of the spinal cord, dorsal or ventral?

Which functions are controlled by the sympathetic nervous system? Which are controlled by the parasympathetic nervous

The medulla, or medulla oblongata, can be considered an extended extension of the spinal cord. Just as the lower parts of the body are connected to the spinal cord by sensory and motor nerves, the head and organs are connected to the brain and adjacent areas by 12 pairs of cranial nerves (one from each pair on the right side and one on the left), as shown in table 3.4 and figure 3.9.

The Midbrain

The term pons is Latin for "bridge" and reflects the fact that in the pons axons from each hemisphere of the brain cross to the other side of the spinal cord, so that the left hemisphere controls the muscles of the right side of the body and the right hemisphere controls the left side. People with cerebellar damage have difficulty switching their attention back and forth between auditory and visual stimuli (Courchesne et al., 1994).

The Forebrain

Figures 3.13 and 3.10 show coronal (from the front) and sagittal (from the side) sections through the human brain. gyrus in the cerebral cortex. The amygdala is part of the circuit most central to the evaluation of emotional information, Figure 3.10.

Thalamus

Most sensory information first goes to the thalamus, which processes it and sends output to the cerebral cortex. Many nuclei of the thalamus receive their information from a sensory system, such as vision, and transmit information to a single area of ​​the cerebral cortex, as in Figure 3.14.

Hypothalamus and Pituitary Gland

The exception to this rule is olfactory information, which goes from the olfactory receptors to the olfactory bulbs and then directly to the cerebral cortex. The cerebral cortex sends information back to the thalamus, prolonging and amplifying certain types of input and focusing attention on certain stimuli (Komura et al., 2001).

Basal Ganglia

Damage to the basal ganglia has long been known to impair movement, as in conditions such as Parkinson's disease and Huntington's disease. We return to the basal ganglia in more detail in the chapters on movement and memory.

Basal Forebrain

The basal ganglia integrate motivational and emotional behavior to increase the strength of chosen actions.

The Ventricles

Which area is the main source of input to the cerebral cortex?

Hippocampus

In Closing

The nervous system of vertebrates has two main divisions, the central nervous system and the peripheral nervous system. The central nervous system consists of the spinal cord, hindbrain, midbrain, and forebrain.

End of Module Quiz

Curiously, the cerebellum occupies an almost constant percentage—about 10 to 14 percent of the brain in most species (Herculano-Houzel et al., 2015). However, elephants have a much larger number of neurons in the cerebellum, proportional to the rest of the brain (Herculano-Houzel et al., 2015).

Organization of the Cerebral Cortex

This means that humans and other primates have a larger cerebral cortex than other species, relative to the rest of the brain. The cells of the cortex are also organized into columns of cells perpendicular to the laminae.

The Parietal Lobe

The Occipital Lobe

If several neurons of the visual cortex all respond best when the retina is exposed to horizontal lines of light, then those

Information about touch and body location is important not only in itself, but also for interpreting visual and auditory information. The parietal lobe monitors all information about eye, head and body positions and transmits it to brain areas that control movement.

The Temporal Lobe

The parietal lobe is essential not only for spatial information but also for numerical information (Hubbard, Piazza, Pinel, & Dehaene, 2005). This overlap makes sense when you consider all the ways in which numbers relate to space—including the fact that we first use our fingers to count.

The Frontal Lobe

For example, if you see something in the upper left field of vision, your brain needs to know which direction your eyes are turned, the position of your head, and how your body is tilted before it can determine its location. of whatever you see.

The Rise and Fall of Prefrontal Lobotomies

• Which lobe of the cerebral cortex includes the primary audi- tory cortex?
• Which lobe of the cerebral cortex includes the primary somatosensory cortex?
• Which lobe of the cerebral cortex includes the primary visual cortex?
• Which lobe of the cerebral cortex includes the primary motor cortex?

Later, Freeman lobotomized people with less severe disorders, including some people we would consider normal by today's standards. People with prefrontal damage have lost their social inhibitions and ignored the rules of polite, civilized behavior.

Functions of the Prefrontal Cortex

In the late 1940s and early 1950s, at a time when legal and ethical restrictions in medicine were lax, approximately 40,000 prefrontal lobotomies were performed in the United States (Shutts, 1982), many of them by Walter Freeman, a medical doctor untrained in surgery. At first, Freeman and others limited the technique to people with severe schizophrenia, for which no effective treatment was available at the time.

How Do the Parts Work Together?

In Closing

The cerebral cortex is the largest part of the human brain, but it is not the entire brain. Damage to part of the occipital lobe leads to blindness in part of the visual field.

End of Module Quiz

For example, researchers have made lesions in parts of the hypothalamus to explore their contribution to eating and drinking. Describing the structure of the brain does not advance our knowledge of biological psychology until we discover how it works.

Effects of Brain Damage

Because surgical removal is difficult for small structures beneath the surface of the brain, researchers sometimes make a lesion, meaning damage, with a stereotaxic instrument, a device for precisely placing electrodes in the brain (see Figure 3.27 ). After the death of the animal, someone takes pieces of its brain, puts the stains and verifies the true location of the damage.

Effects of Brain Stimulation

New technologies allow researchers to record tens to hundreds of neurons simultaneously (Luczak, McNaughton, &. Harris, 2015). The first step was to discover or invent a protein that responds to light by producing an electric current.

Recording Brain Activity

The numbers on the brain on the left show hypothetical levels of arousal during some task, measured in arbitrary units. The brain in the center shows activity in the same brain areas during a comparison task.

Correlating Brain Anatomy with Behavior

• What does fMRI measure?
• Suppose someone demonstrates that a particular brain area becomes active when people are listening to music. When that
• What are the similarities and differences between MRI and fMRI?
• In Closing
• End of Module Quiz

Comparison of MRI and fMRI, which measure the responses of brain chemicals to a magnetic field. Why we should be cautious when interpreting many of the reports linking certain aspects of brain anatomy to behavior.

Genetics, Evolution, Development,

The human nervous system requires a tremendous amount of assembly, and the instructions are different from those that apply to the objects we assemble from a kit. Put these axons here and those dendrites there, and then wait and see what happens.

The researchers examined the facial expressions of people who were born blind and therefore could not have learned to imitate facial expressions. The facial expressions of people born blind were remarkably similar to those of their sighted relatives, as shown in Figure 4.1 (Peleg et al., 2006).

Mendelian Genetics

A contribution from the environment is obvious: you smile more when the world treats you well and frown when things go badly. Therefore, a child in this family has a 25 percent chance of two T genes, a 50 percent chance of the heterozygous state, and a 25 percent chance of being homozygous for the t gene.

Sex-Linked and Sex-Limited Genes

Suppose you have high sensitivity to tasting PTC. If your mother can also taste it easily, what (if anything) can you

Sex-limited genes are different from sex-linked genes, which are present in both sexes, but active mainly in one sex. Both sexes have genes, but sex hormones activate them in one sex and not in the other, or one sex much more than the other.

Genetic Changes

X chromosomes contain a gene for color vision deficiency, then 8 percent of males will have color deficiency, but less than one percent of females will. Examples include genes that regulate the amount of chest hair in men, breast size in women, the amount of crowing in roosters, and the rate of egg production in hens.

Epigenetics

How does a sex-linked gene differ from a sex-limited gene?

Acetyl groups that attach to the loose end of a histone molecule loosen the histone's grip on DNA, exposing more genes to the possibility of being active.

How does an epigenetic change differ from a mutation?

How does adding a methyl or acetyl group to a histone pro- tein alter gene activity?

Heredity and Environment

What are the main types of evidence to estimate the heritabil- ity of some behavior?

Suppose someone determines the heritability of IQ scores for a given population. Then society changes in a way that pro-

Environmental Modification

What example illustrates the point that even if some charac- teristic is highly heritable, a change in the environment can

Therefore, the current generation of each species resembles the individuals that reproduced in the past. If a change in the environment causes another gene to increase the probability of survival and reproduction, then that gene will spread through the population.

Common Misunderstandings about Evolution

Some individuals reproduce more than others, passing their genes on to the next generation. Any gene associated with greater reproductive success will become more prevalent in later generations.

How Genes Influence Behavior

In contrast, the question of how species evolve is a question of how the process works, and this process is a necessary result of what we know about reproduction. If some individuals are more successful than others at finding food, escaping enemies, resisting disease, attracting mates, or protecting their offspring, then their genes will become more spread to later generations.

The Evolution of Behavior

Many people believe the human appendix is useless. Will it become smaller and smaller with each generation?

The appendix will only shrink smaller in the next generation than people with a gene for a smaller ap. If that gene enables you to leave more surviving children than you would otherwise have, then that gene will increase in prevalence in your population.

Evolutionary Psychology

What are plausible ways for possible altruistic genes to spread in a population?

Genes are chemicals that maintain their integrity from one generation to another and influence the development of the individual. Even if some behaviors show high heritability for a given population, a change in the environment can significantly change the outcome of the behavior.

In Closing

Experiences can cause epigenetic changes, and in some cases the epigenetic change can affect the next generation. Heritability is an estimate of the amount of variation that is due to genetic variation as opposed to environmental variability.

End of Module Quiz

MZ twins are one male and one female, while DZ twins are of the same sex. MZ twins are of the same sex, while DZ twins are one male and one female.

Maturation of the Vertebrate Brain

Think of all the things you can do that you couldn't have done a few years ago - analyze statistics, read a foreign language, write brilliant reviews of complex issues, and so on. In general, areas of the brain that develop more slowly, such as the prefrontal cortex, are the ones most likely to deteriorate in conditions such as Alzheimer's disease (Douaud et al., 2014).

Growth and Development of Neurons

Which comes first: migration, synaptogenesis, or myelination?

They continue to develop, of course, but the biggest changes during the first few years occur in the prefrontal cortex and other cortical areas responsible for attention, working memory and decision-making (Alcuter et al., 2014; G. Li. et al., 2014).

New Neurons Later in Life

New receptor neurons form in which sensory system?

What evidence indicates that new neurons form in the human hippocampus and basal ganglia?

Pathfinding by Axons

Chemical Pathfinding by Axons

In the 1600s, Descartes thought the nervous system worked like a hydraulic pump, the most advanced technology of the time. Today, many people think that the nervous system works like a computer, our most advanced technology.).

Specificity of Axon Connections

The 1920s were the early days of radio, and it was an attractive analogy to think that the nervous system could work like a radio.

Chemical Gradients

What was Sperry’s evidence that axons grow to a specific target instead of attaching at random?

By analogy, you could think of men queuing from longest to shortest, and women queuing from longest to shortest.

As a result, axons from adjacent areas of the retina send nearly simultaneous messages to the thalamus. The functioning of the brain depends on the accuracy and patterns of its neural circuits.

Determinants of Neuronal Survival

If axons from the retina were prevented from showing spon- taneous activity during early development, what would be

In fact, all areas of the developing nervous system produce more neurons than will survive into adulthood. Experimenters transplanted additional neurons into the mouse cortex with no apparent effect on the survival of neurons already present (Southwell et al., 2012).

The Vulnerable Developing Brain

What process assures that the spinal cord has the right number of axons to innervate all the muscle cells?

Neurotrophins are essential for the growth of axons and dendrites, the formation of new synapses, and learning (Alleva & Francia, 2009; Pascual et al., 2008; Rauskolb et al., 2010). The brain initially acquired normal anatomy, but then neurons began to die rapidly (Verhage et al., 2000).

What class of chemicals prevents apoptosis in the sympathetic nervous system?

As a result of the decrease in net excitation, many neurons undergo apoptosis (Ikonomidou et al., 2000). Did the visual input cause auditory sensations, or did the auditory areas of the brain turn into visual areas.

Differentiation of the Cortex

In the ferret study, how did the experimenters determine that visual input to the auditory portions of the brain actually

Therefore, the optic nerve could not attach to its usual target, and the auditory area of ​​the thalamus did not have its usual input. As a result, the optic nerve attaches to what is normally the auditory area of ​​the thalamus.

Fine-Tuning by Experience

Experience and Dendritic Branching

In short, blind people, unlike sighted people, use the occipital cortex to help identify what they are feeling (Cohen et al., 1997). In people who have been blind since birth, the occipital cortex also responds to auditory information (Watkins et al., 2013), especially language (Bedny, Richardson, & Saxe, 2015).

Effects of Special Experiences

Just as people who have been blind since childhood become more sensitive to touch and sound, people who have been deaf since childhood become more sensitive to touch and vision. Just as touch and sound activate what would be the visual cortex in blind people, touch and vision activate what would be the auditory cortex in deaf people (Karns, Dow, & . Neville, 2012).

Brain Adaptations in People Blind since Infancy

Name two kinds of evidence indicating that touch informa- tion from the fingers activates the occipital cortex of people

Applying this procedure to the occipital cortex of people who are blind disrupts their ability to identify Braille symbols, whereas it does not affect touch perception in sighted people. The auditory cortex not only responds to vision, but specifically responds to certain aspects of vision.

Music Training

Which brain area shows expanded representation of the left hand in people who began practicing stringed instruments in

Brain Changes after Briefer Practice

When Brain Reorganization Goes Too Far

This condition, known as "musician's cramp" or more formally as focal hand dystonia, can threaten a musician's career. A person with musician's cramp or writer's cramp has difficulty moving a finger independently of others.

Brain Development and Behavioral Development

Adolescence

What change in the brain is responsible for musician’s cramp?

Old Age

• Why is immaturity of the prefrontal cortex not a satisfactory explanation for risky behaviors in adolescents?
• What is one way in which older adults compensate for less efficient brain functioning?
• In Closing
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Optic nerve axons grew back into targets suited to their new location in the eye. The research with ferrets shows that there is evidence that visual input to the auditory parts of the brain actually caused a visual sensation.

Brain Damage and Short-Term Recovery

Some of the mechanisms rely on the growth of new branches from axons and dendrites, similar to the mechanisms of brain development. Understanding the process leads to better therapies for people with brain damage and adds to our understanding of brain functioning.

Reducing the Harm from a Stroke

When asked to read the letterhead, "New York University College of Medicine," he replied. Doctors—little doctors.” Eight years later, when someone asked him again to read the letterhead, he replied: “Is there a catch.

Immediate Treatments

It is difficult to know how much of the difference in outcome was due to a possible beneficial effect of marijuana, and how much was due to the difference in age. A similar problem relates to reports (Wolff et al., 2013) that marijuana users have a higher than average risk of certain physical and mental illnesses: does marijuana increase the risk of conditions.

Increased Brain Stimulation

What are the two kinds of stroke, and what causes each kind?

Why is tPA not helpful in cases of hemorrhage?

Later Mechanisms of Recovery

After someone has had a stroke, would it be best (if possible) to direct stimulant drugs to the cells that were damaged or

Regrowth of Axons

In order to function properly, the animal needs a lot of practice with the relevant movements (Hollis et al., 2016; Wahl et al., 2014). If the damaged axons were sensory and not motor, then extensive sensory experience is required for the axons to recover their function (Lim et al., 2016).

Axon Sprouting

Astrocytes release chemicals that keep nearby neurons alive, and procedures that remove the scar cause tissue degeneration (Anderson et al., 2016; Sabelström et al., 2013). Many chemicals can stimulate regrowth, and research in laboratory rats has shown that such chemicals sometimes allow axons to return to their normal targets (Anderson et al., 2016; Ruschel et al., 2015; Wong, Gibson, Arnold, Pepinsky , & Frank, 2015).

Denervation Supersensitivity

Is collateral sprouting a change in axons or dendritic receptors?

In short, researchers have made a lot of progress in facilitating regrowth of damaged axons in laboratory animals.

Reorganized Sensory Representations and the Phantom Limb

A touch on the face now produces a face sensation, but it also produces a sensation in the phantom hand. One reported feeling orgasm in the phantom foot as well as the genitals—and enjoying it intensely (Ramachandran & Blakeslee, 1998).

Learned Adjustments in Behavior

• What is responsible for the phantom limb experience?
• A monkey that loses sensation from one arm stops using it, but a monkey that loses sensation from both arms does use
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One of the most thought-provoking books ever written on human brain damage, including the phantom limb phenomenon. Further processing The primary visual cortex Development of the visual cortex In conclusion: Understanding Vision by.

Vision

Discuss specific deficits that can occur after damage to parts of the visual cortex, such as impaired face recognition or impaired movement perception. Here is one of the most important principles to remember from this text: When you see a tree, for example, your perception is not in the tree.

General Principles of Perception

What was Ibn al-Haytham’s evidence that we see only because light enters the eyes, not by sending out sight rays?

When the blind spot interrupts a straight line or other regular pattern, your brain fills in the gap. Second, anything in the blind spot of one eye is visible to the other eye.

If someone electrically stimulated the auditory receptors in your ear, what would you perceive?

The point where it leaves (also where the blood vessels enter and leave) is a blind spot because it has no receptors. When the page is about 10 inches (25 cm) away, the x disappears because its image hits the blind spot.

If it were possible to flip your entire brain upside down, without breaking any of the connections to sense organs or

A consequence of this anatomy is that light passes through ganglion, amacrine, and bipolar cells on the way to the receptors. When the page is again about 10 inches away from your eyes, what do you see?

The Eye and Its Connections to the Brain

Additional cells called amacrine cells pick up information from bipolar cells and send it to other bipolar, amacrine and ganglion cells. The axons of the ganglion cell join to form the optic nerve, which exits through the back of the eye.

Route within the Retina

What makes the blind spot of the retina blind?

Amacrine cells refine input to ganglion cells, allowing some to respond primarily to certain shapes, directions of movement, changes in lighting, color, and other visual features (Masland, 2012). If you rub your eyes, you can see spots or flashes of light even in a totally dark room.

Fovea and Periphery of the Retina

Conversely, many prey species such as rats have most of their receptors on the lower half of the retina, making this possible. The axons of the ganglion cells form the optic nerve, which leaves the eye at the blind spot and continues to the brain.

Visual Receptors: Rods and Cones

You sometimes find that you can see a faint star on a dark night better if you look slightly to the side of the star instead

If you found a species with a high ratio of cones to rods in its retina, what would you predict about its way of life?

Color Vision

According to the trichromatic theory, we distinguish between wavelengths by the ratio of activity across the three types of cones. The nervous system determines the color of light by comparing the responses of different types of cones.

The Trichromatic (Young-Helmholtz) Theory

For example, imagine a bipolar cell that receives excitation from a short-wavelength cone and inhibition from long- and medium-wavelength cones. Although the short-wavelength (blue) cones are roughly evenly distributed across the retina, the other two types are randomly distributed, with large differences between individuals (Solomon & Lennie, 2007).

The Opponent-Process Theory

According to the opponent-process theory, under what cir- cumstance would you perceive a white object as blue?

An e object is only if the long wavelength is conical to a bright yellow object response relative to the other two types of e or so and then looks at a white 8.

The Retinex Theory

However, because women have two X chromosomes, some women have one long-wavelength receptor with serine and one with alanine. These two versions of the long-wavelength receptor differ slightly in their response to light (Deeb, 2005).

Color Vision Deficiency

Why is color vision deficiency a better term than color blindness?

To account for the constancy of color and brightness, Edwin Land proposed the retinex theory (a combination of the words retina and cortex): The cortex compares information from different parts of the retina to determine brightness and color for each area (Land, Hubel, Livingstone, Perry, & Burns, 1983). When you watch a program, parts of the screen appear black, you watch a program, parts of the screen appear black, even though there is actually more light on the screen than when the camera was turned off.

In Closing

End of Module Quiz

Second, neuroscientists have studied vision in more detail than anything else the brain does.

An Overview of the Mammalian Visual System

Where does the optic nerve start and where does it end?

Processing in the Retina

When light strikes a receptor, does the receptor excite or inhibit the bipolar cells? What effect does it have on hori-

Next is the horizontal cell, which inhibits all bipolar cells, since the nearby one produces only inhibition. In the cross inhibited by input on all f, the response in cr compared with that in arms.

Further Processing

As we progress from bipolar cells to ganglion cells to later cells in the visual system, are receptive fields ordinarily

What are the differences between the parvocellular and magnocellular systems?

The Primary Visual Cortex

Tilting the bar reduces the cell's response somewhat because light then also hits inhibitory areas.

Simple and Complex Receptive Fields

If you were in a darkened room and researchers wanted to

What is an example of an unconscious response to visual information?

The Columnar Organization of the Visual Cortex

How could a researcher determine whether a given neuron in the visual cortex is simple or complex?

Are Visual Cortex Cells Feature Detectors?

What do cells within a column of the visual cortex have in common?

A branch of mathematics called Fourier analysis demonstrates that a combination of sine waves can produce an unlimited variety of other patterns. For example, the graph at the top of the following screen is the sum of the five sine waves below it:

What is a feature detector?

Thus, an array of spatial frequency detectors, some sensitive to horizontal patterns and others to vertical patterns, could represent any possible representation. Many cortical neurons respond best to a particular spatial frequency and barely to other frequencies (DeValois, Albrecht, & Thorell, 1982).

Development of the Visual Cortex

With a little time and effort you can get an "Aha" experience when you suddenly see them as faces. Therefore, most visual researchers believe that neurons in area V1 detect spatial frequencies rather than bars or edges.

Uncorrelated Stimulation in the Two Eyes

Deprived Experience in One Eye

Deprived Experience in Both Eyes

What is the effect of closing one eye early in life? What is the effect of closing both eyes?

Early Exposure to a Limited Array of Patterns

What early experience would cause a kitten or human child to lose stereoscopic depth perception?

If so, turn the page to show that the subject is in you, not in the lines themselves. If you see a difference in the lines just without the lenses, the lenses have corrected your astigmatism.

Impaired Infant Vision

By two years later, he was willing to open his eyes while skiing, and he could use vision to estimate the steepness of a hill. Apparently, the visual understanding that most of us take for granted depends on practice early in life.

• What causes astigmatism?
• If an infant is born with dense cataracts on both eyes and they are surgically removed years later, how well does the
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Neurons within a column of primary visual cortex have similar properties, such as responding to lines in the same orientation. What early experience, if any, is necessary to maintain binocular input to visual cortex neurons.

The Ventral and Dorsal Paths

Someone else who keeps track of the finances needs to know how much the object costs and whether it needs insurance. In the same way, different parts of the brain's visual system receive information on a need-to-know basis.

The Inferior Temporal Cortex

Suppose someone can describe an object in detail but stumbles and fumbles when trying to walk toward it and

Areas V2 and V3 (see Figure 5.27) have some cells that are highly responsive to color, and other cells that are highly responsive to differences between what the left and right eyes see.

Detailed Analysis of Shape

And an area close to this face area responds more strongly to bodies than to anything else (Downing, Chan, Peelen, Dodds, & Kanwisher, 2005; . Kanwisher, 2010). The brain is amazingly adept at detecting biological motion—the kind of motion produced by humans and animals.

Recognizing Faces