Chapter 3 Introduction

3Neuroscience and Behavior

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  • Neurons: The Origin of Behavior

    • Components of the Neuron
    • Major Types of Neurons
  • Information Processing in Neurons

    • Electric Signaling: Conducting
    • Information within a Neuron
    • Chemical Signaling: Transmission between Neurons
  • The Organization of the Nervous System

    • The Peripheral Nervous System
    • The Central Nervous System
  • Structure of the Brain

    • The Hindbrain
    • The Midbrain
    • The Forebrain
    • Brain Plasticity
    • THE REAL WORLD Brain Plasticity and Sensations in Phantom Limbs
  • The Development and Evolution of Nervous Systems

    • Prenatal Development of the Central Nervous System
    • Evolutionary Development of the Central Nervous System
    • Genes and Epigenetics
    • HOT SCIENCE Epigenetics and the Persisting Effects of Early Experiences
  • Investigating the Brain

    • Studying the Damaged Brain
    • Studying the Brain’s Electrical Activity
    • Using Brain Imaging to Study Structure and to Watch the Brain in Action
    • OTHER VOICES Neuromyths
Ray Easterling (left) and Dave Duerson (right) had similarly outstanding NFL careers and similarly troubled retirements, perhaps associated with brain damage.
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Michael J. Minard/Getty Images

Ray Easterling and Dave Duerson came from different times and places, but both loved football and played the position of defensive back well enough to star in college and make it all the way to the National Football League–Easterling for the Atlanta Falcons during the 1970s, and Duerson for the Chicago Bears in the 1980s. Unfortunately, the parallels between Easterling and Duerson continued into their retirement years. Both men suffered from significant cognitive decline and depression, and both ended up taking their own lives: Duerson in 2011, Easterling in 2012. Postmortem analyses of their brains revealed the presence of a condition known as chronic traumatic encephalopathy (CTE), a form of progressive brain damage that has been linked to repeated concussions (McKee et al., 2012). Duerson and Easterling are just 2 of over 20 former NFL players who have been diagnosed with CTE, and the condition has also been observed after repeated head injuries in boxing, wrestling, hockey, and rugby (Costanza et al., 2011; Daneshvar et al., 2011; Lahkan & Kirchgessner, 2012; McKee et al., 2012).

We don’t know whether CTE contributed to the demise of either Easterling or Duerson, but we do know that CTE is associated with an array of cognitive and emotional deficits in afflicted individuals, including an inability to concentrate, memory loss, irritability, and depression, usually beginning within a decade after repeated concussions and worsening with time (McKee et al., 2009). Fortunately, there is growing awareness of CTE and its consequences, which is leading professional sports organizations, as well as colleges, schools, and others involved in youth sports, to take steps to address the problem.

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DATA VISUALIZATION

Concussion Rates in High School and College Athletes www.macmillanhighered.com/launchpad/schacterbrief3e

The symptoms of CTE, and the havoc they can wreak in the lives of affected individuals and their families, are stark reminders that our psychological, emotional, and social well-being depends critically on the health and integrity of the brain. The more we know about the brain, the better our chances of finding solutions to problems such as CTE. In this chapter, we’ll consider how the brain works, what happens when it doesn’t, and how both states of affairs determine behavior. First, we’ll introduce you to the basic unit of information processing in the brain, the neuron. The electrical and chemical activities of neurons are the starting point of all behavior, thought, and emotion. Next, we’ll consider the anatomy of the central nervous system, focusing especially on the brain, its overall organization, and its evolutionary development. Finally, we’ll discuss methods that allow us to study both damaged and healthy brains.