RECENT DEVELOPMENTS: COGNITIVE NEUROSCIENCE AND SOCIAL NEUROSCIENCE

Despite disagreement over whether the mind-brain relationship will ever be fully understood and what form that understanding will take, the assumption of a strong connection between the two has been highly productive. It stimulated the work of Penfield and Milner in the first place, and continues to generate fascinating explorations to more fully explain the most human of all capacities: the awareness of our own consciousness. The prominent psychologist and neuroscientist V. S. Ramachandran has called the effort to understand how the brain gives rise to the mind, thus accomplishing an awareness of itself, the “holy grail” of neuroscience.

This search for the holy grail has been steadily advancing, in part through the use of increasingly powerful imaging techniques that have enabled detailed observations of the brain structures and neural activities that accompany specific mental processes. Many of these techniques fall under the general category of tomography, the imaging of objects as collections of sections, or slices, created by various kinds of penetrating waves. The most common types of images, or scans, are from CT (computed tomography), based on X-rays, and MRI (magnetic resonance imaging), which uses radio waves to produce images of magnetically aligned atoms within the object. When the object being observed is a living organ such as the brain, positron emission tomography (PET) can also be done, to detect concentrations of injected radioactive “tracer” molecules, which indicate metabolic activity in different parts of the brain. Less invasive and more efficient fMRI (functional MRI) procedures can provide images of blood oxygenation (an indirect measure of blood flow) to reflect neural activity in specific brain regions.

Along with these technological developments, a shift was occurring in the field of academic psychology that is sometimes referred to as the cognitive revolution. The word resurgence is more appropriate, because cognitive functions—those relating to such processes as thinking, reasoning, memory, and perception—had long been considered an important domain of psychology. During much of the early and mid-twentieth century, however, the movement known as behaviorism became dominant, particularly among English-speaking academic psychologists. Behaviorists declared that only directly and “objectively” observable behavior was appropriate subject matter for scientific psychology. Anything not directly and objectively observable, including subjective introspections, thoughts, reasoning, and so on, was ruled off limits. Chapters 9 and 14 will discuss these topics in detail, but for now we simply note that throughout the latter half of the twentieth century, psychologists increasingly returned to cognitive processes as major subjects for their investigations and analyses. As noted earlier, the work of Milner and her colleagues revealing some of the complexities of memory is one example of this trend.

Perhaps inevitably, technological advances in brain imaging and revived interest in cognition came together, as cognitive psychologists, as well as investigators from diverse disciplines who were interested in neuroscience, began using the new techniques to learn what actually goes on in different parts of the brain as various cognitive activities are performed. This localization research was in the same tradition as that described throughout this chapter, but with a previously undreamed-of precision. In the late 1970s the pioneering cognitive psychologist George Miller and the younger neuroscientist Michael Gazzaniga called the new interdisciplinary field cognitive neuroscience. Both the field and its name took off, and initial accomplishments included PET studies of brain activity during varying states of attention and memory by the psychologist Michael Posner and neurologist Marcus Raichle in the 1980s. The psychologist Stephen Kosslyn used fMRI technology to show that the brain activities that accompany mental imagery are not unified or localized in a single region; they occur in diverse regions, each responsible for different aspects of the imaging process. Too diverse and complex to be summarized here, the main accomplishments of the new field have been summarized by Gazzaniga and two colleagues in their book Cognitive Neuroscience: The Biology of the Mind.26

The excitement generated by these increasingly sophisticated methods for “seeing” inside the brain and uncovering the neurological correlates of human behavior has also extended into traditionally “soft” areas, such as social psychology (see Chapter 10). Researchers combining their interest in understanding how the brain processes social information with advanced imaging techniques refer to the field as social neuroscience, or social cognitive neuroscience. Their aim is to explore the neural mechanisms underlying social thought and behavior and they have established new journals for the area, such as Social Neuroscience and Social Cognitive and Affective Neuroscience. The journal Social Neuroscience, founded in 2006, stated its goal to “publish empirical articles that . . . further our understanding of the role of the central nervous system in the development and maintenance of social behaviors.”27 Studies reporting behavioral data in isolation, the journal editors noted, would not be considered. Although the American Psychological Association declared 2000–2010 to be the Decade of Behavior, it seems certain that research efforts to understand behavior will become increasingly tied to neuroscience as the field moves further into the twenty-first century.