Coda

This concluding chapter highlights the book's aim to document the value of gathering patterns of measures representing possible causes of outcomes and evaluating their predictive power with patterns of measures, many of which should be brain profiles. Investigators should gather as many different sources of evidence as they can because a variable thought to be irrelevant can be a clue to understanding. Ultimately, the research posture advocated in this book requires neuroscientists and psychologists to be more concerned than they have been with the features in the laboratory setting, the details in the procedure, the participants' expectations, the specific evidence cited as the basis for an inference, and the vocabulary used to describe a brain or behavioral outcome.

Expectedness

This chapter analyzes how subject expectations affect all brain measures. An expectation of pain, a difficult task, an unpleasant picture, an air puff to the face, the sound of hands clapping, a metaphorical sentence, a caress, cocaine, an exemplar of a semantic category, or the benefit of a medicine each affects brain profiles as well as the speed and accuracy of perceptions. Meanwhile, unexpected events activate many brain sites, but especially the amygdala, hippocampus, prefrontal cortex, ventral tegmental area, and locus ceruleus. The difference in the oscillation frequencies evoked by the event anticipated and the one that occurs may be a critical cause of these activations. The brain and psychological states generated by an unexpected event depend on its desirability and familiarity.

The Power of the Context

This chapter discusses contextual constraints on brain profiles. The laboratories that measure brain activity contain uncommon combinations of physical features and incentives that prime some brain sites and suppress others. Despite these possibilities, neuroscientists continue to speculate about the implications of the brain patterns they record as if the context has a minimal influence on their observations. This position is difficult to defend given the fact that the parahippocampal cortex binds objects and events to the context in which they appear. Adults lying supine and still in the narrow tube of a magnetic scanner in an unfamiliar room are in an unusual psychological and bodily state. The compromised sense of agency, awareness of being evaluated, confinement in a narrow space, and the demand to suppress all movement affect brain and psychological processes.

Introduction

This introductory chapter provides an overview of the five constraints on the ability to predict mental or behavioral outcomes based on brain data. Some psychologists and neuroscientists fail to attribute sufficient power to the context of observation. The subject's expectations comprise a second constraint on inferences. Meanwhile, a large number of investigators studying brain–behavior relations resist Niels Bohr's insight that the validity of every conclusion depends on its source of evidence. One reason why brain and psychological data yield conclusions with differing validities is that some brain measures are subject to the effects of bodily processes that exert minimal effects on many psychological observations. The last constraint to be considered is the practice of borrowing predicates whose meanings and validities originated in psychological measures gathered on human subjects and applying them to brain patterns, or to animals.

Patterns

This chapter evaluates the suggestion that the constrained validity of conclusions based on a single source of evidence—whether behavior, brain data, or verbal report—implies that patterns of observations might provide statements that have a less constrained validity. Neuroscientists find it helpful to conceive of the brain as a collection of hubs receiving large numbers of inputs from many diverse sites and selecting outputs as a function of the pattern of incoming signals. Different patterns of inputs arriving at different hubs can generate similar outcomes. Most of the outcomes people care about—suicide, homicide, grade point average, anxiety, depression, drug abuse, or well-being—require patterns of conditions that include a person's biology, social class, family, school experiences, and always the cultural setting.

Attributing Psychological Properties to Brain Profiles

This chapter focuses on the constraints of attributing psychological properties to brain profiles. The constraint on the validity of inferences based on one source of evidence bears directly on the neuroscientist's habit of describing brain profiles with words whose meaning and validity originated in psychological data. This practice deserves careful scrutiny because animals or humans are the presumed agents in sentences containing terms describing the psychological processes of perception, memory, intention, feeling, emotion, reasoning, or action. These terms take on novel meanings in sentences in which neuronal activity is the noun. However, the practice of using psychological predicates—such as compute, regulate, or synthesize—to describe brain profiles remains popular because neuroscientists do not have a rich biological vocabulary for the diverse brain profiles that occur in response to incentives.

Sources of Evidence

This chapter examines the relations between patterns of causes and outcomes. The popular way to phrase Niels Bohr's principle that the validity of every conclusion depends on its source of evidence is to write that scientists assign a probability to the validity of each statement in accord with the evidence cited to support it. Statements that refer to exactly the same observation can have more than one validity if they are based on different evidence. It is useful to distinguish among the validity of a statement about nature that is based on certain observations, the truth of a conclusion that is based on the coherence of a logical or mathematical argument, and the rightness of a moral proposition based on a feeling.