Annual Review of Psychology - Volume 55, 2004

To build a science of the person, the most basic question was, and remains, how can one identify and understand the psychological invariance that distinctively characterizes an individual and that underlies the variations in the thoughts, feelings, and actions that occur across contexts and over time? This question proved particularly difficult because of the discrepancies that soon emerged between the expressions of consistency that were expected and those that were found. The resulting dilemma became known as the classic “personality paradox”: How can we reconcile our intuitions—and theories—about the invariance and stability of personality with the equally compelling empirical evidence for the variability of the person's behavior across diverse situations? Which is right: the intuitions or the research findings? In this chapter I review and discuss some of the advances made to answer this question since it was posed. These findings have allowed a resolution of the paradox, and provide the outlines for a conception of the underlying structure and dynamics of personality that seems to better account for the data.

Cognitive neuroscience is motivated by the precept that a discoverable correspondence exists between mental states and brain states. This precept seems to be supported by remarkable observations and conclusions derived from event-related potentials and functional imaging with humans and neurophysiology with behaving monkeys. This review evaluates specific conceptual and technical limits of claims of correspondence between neural events, overt behavior, and hypothesized covert processes examined using data on the neural control of saccadic eye movements.

Consolidation is the progressive postacquisition stabilization of long-term memory. The term is commonly used to refer to two types of processes: synaptic consolidation, which is accomplished within the first minutes to hours after learning and occurs in all memory systems studied so far; and system consolidation, which takes much longer, and in which memories that are initially dependent upon the hippocampus undergo reorganization and may become hippocampal-independent. The textbook account of consolidation is that for any item in memory, consolidation starts and ends just once. Recently, a heated debate has been revitalized on whether this is indeed the case, or, alternatively, whether memories become labile and must undergo some form of renewed consolidation every time they are activated. This debate focuses attention on fundamental issues concerning the nature of the memory trace, its maturation, persistence, retrievability, and modifiability.

Evidence from developmental psychology suggests that understanding other minds constitutes a special domain of cognition with at least two components: an early-developing system for reasoning about goals, perceptions, and emotions, and a later-developing system for representing the contents of beliefs. Neuroimaging reinforces and elaborates upon this view by providing evidence that (a) domain-specific brain regions exist for representing belief contents, (b) these regions are apparently distinct from other regions engaged in reasoning about goals and actions (suggesting that the two developmental stages reflect the emergence of two distinct systems, rather than the elaboration of a single system), and (c) these regions are distinct from brain regions engaged in inhibitory control and in syntactic processing. The clear neural distinction between these processes is evidence that belief attribution is not dependent on either inhibitory control or syntax, but is subserved by a specialized neural system for theory of mind.

The hypocretins (Hcrts, also known as orexins) are two peptides, both synthesized by a small group of neurons, most of which are in the lateral hypothalamic and perifornical regions of the hypothalamus. The hypothalamic Hcrt system directly and strongly innervates and potently excites noradrenergic, dopaminergic, serotonergic, histaminergic, and cholinergic neurons. Hcrt also has a major role in modulating the release of glutamate and other amino acid transmitters. Behavioral investigations have revealed that Hcrt is released at high levels in active waking and rapid eye movement (REM) sleep and at minimal levels in non-REM sleep. Hcrt release in waking is increased markedly during periods of increased motor activity relative to levels in quiet, alert waking. Evidence for a role for Hcrt in food intake regulation is inconsistent. I hypothesize that Hcrt's major role is to facilitate motor activity tonically and phasically in association with motivated behaviors and to coordinate this facilitation with the activation of attentional and sensory systems. Degeneration of Hcrt neurons or genetic mutations that prevent the normal synthesis of Hcrt or of its receptors causes human and animal narcolepsy. Narcolepsy is characterized by an impaired ability to maintain alertness for long periods and by sudden losses of muscle tone (cataplexy). Administration of Hcrt can reverse symptoms of narcolepsy in animals, may be effective in treating human narcolepsy, and may affect a broad range of motivated behaviors.

This chapter focuses on one of the first steps in comprehending spoken language: How do listeners extract the most fundamental linguistic elements—consonants and vowels, or the distinctive features which compose them—from the acoustic signal? We begin by describing three major theoretical perspectives on the perception of speech. Then we review several lines of research that are relevant to distinguishing these perspectives. The research topics surveyed include categorical perception, phonetic context effects, learning of speech and related nonspeech categories, and the relation between speech perception and production. Finally, we describe challenges facing each of the major theoretical perspectives on speech perception.

Psychophysical experiments on feature tracking suggest that most of our sensitivity to chromatic motion and to second-order motion depends on feature tracking. There is no reason to suppose that the visual system contains motion sensors dedicated to the analysis of second-order motion. Current psychophysical and physiological data indicate that local motion sensors are selective for orientation and spatial frequency but they do not eliminate any of the three main models—the Reichardt detector, the motion-energy filter, and gradient-based sensors. Both psychophysical and physiological data suggest that both broadly oriented and narrowly oriented motion sensors are important in the early analysis of motion in two dimensions.

Formal theories of attention based on similarity-choice theory and signal-detection theory are reviewed to document cumulative progress in theoretical understanding of attention from the 1950s to the present. Theories based on these models have been developed to account for a wide variety of attentional phenomena, including attention to dimensions, attention to objects, and executive control. The review describes the classical similarity-choice and signal-detection theories and relates them to current theories of categorization, Garner tasks, visual search, cuing procedures, task switching, and strategy choice.

Traditional theories of forgetting are wedded to the notion that cue-overload interference procedures (often involving the A-B, A-C list-learning paradigm) capture the most important elements of forgetting in everyday life. However, findings from a century of work in psychology, psychopharmacology, and neuroscience converge on the notion that such procedures may pertain mainly to forgetting in the laboratory and that everyday forgetting is attributable to an altogether different form of interference. According to this idea, recently formed memories that have not yet had a chance to consolidate are vulnerable to the interfering force of mental activity and memory formation (even if the interfering activity is not similar to the previously learned material). This account helps to explain why sleep, alcohol, and benzodiazepines all improve memory for a recently learned list, and it is consistent with recent work on the variables that affect the induction and maintenance of long-term potentiation in the hippocampus.

We perceive the shapes and material properties of objects quickly and reliably despite the complexity and objective ambiguities of natural images. Typical images are highly complex because they consist of many objects embedded in background clutter. Moreover, the image features of an object are extremely variable and ambiguous owing to the effects of projection, occlusion, background clutter, and illumination. The very success of everyday vision implies neural mechanisms, yet to be understood, that discount irrelevant information and organize ambiguous or noisy local image features into objects and surfaces. Recent work in Bayesian theories of visual perception has shown how complexity may be managed and ambiguity resolved through the task-dependent, probabilistic integration of prior object knowledge with image features.

The midlife period in the lifespan is characterized by a complex interplay of multiple roles. The goal of this chapter is to summarize research findings on the central themes and salient issues of midlife such as balancing work and family responsibilities in the midst of the physical and psychological changes associated with aging. The field of midlife development is emerging in the context of large demographic shifts in the population. A section on the phenomenology of midlife development presents images and expectations including the seemingly disparate views of midlife as a time of peak functioning and a period of crisis. Conceptual frameworks useful for studying the multiple patterns of change in midlife are presented. Findings demonstrating patterns of gains and losses are reviewed for multiple domains: cognitive functioning, personality and the self, emotions, social relationships, work, and physical health. The need for future research to illuminate and integrate the diverse aspects of midlife is highlighted.

The recurrence of social, behavioral, and health problems in successive generations of families is a prevalent theme in both the scientific and popular literatures. This review discusses recent conceptual models and findings from longitudinal studies concerning the intergenerational transfer of psychosocial risk, including intergenerational continuity, and the processes whereby a generation of parents may place their offspring at elevated risk for social, behavioral, and health problems. Key findings include the mediational effects of parenting and environmental factors in the transfer of risk. In both girls and boys, childhood aggression and antisocial behavior appear to predict long-term trajectories that place offspring at risk. Sequelae of childhood aggression that may threaten the well-being of offspring include school failure, adolescent risk-taking behavior, early and single parenthood, and family poverty. These childhood and adolescent behavioral styles also predict harsh, aggressive, neglectful, and unstimulating parenting behavior toward offspring. Buffering factors within at-risk families include maternal educational attainment and constructive parenting practices (e.g., emotional warmth, consistent disciplinary practices, and cognitive scaffolding). These findings highlight the potential application and relevance of intergenerational studies for social, educational, and health policy.

In this chapter we review theoretical conceptual and empirical advances in family research and the implications for children's development. Three interdependent family subsystems are considered: the parent-child subsystem, the marital subsystem, and the sibling subsystem. Recent work on the family as a unit of analysis is reviewed as well. Several determinants of family socialization strategies are noted, including child and parental characteristics and resources and social capital available to families. Ethnicity is considered by reviewing recent advances in our understanding of African American, Asian American, and Hispanic families. Several new directions in family research are highlighted. These include research on the linkage between families and work, gay and lesbian parenting, the new reproductive technologies, and the effect of parental incarcerations on families. Future trends in family research are noted, including the role of genetics, the biological correlates of family processes, the role of intervention and prevention designs in family research, and the importance of process work on ethnicity-oriented family research.

Decades of research on schizophrenia have not produced major breakthroughs, but gradual progress has been made in identifying risk factors and clarifying the nature of the etiologic process. This article provides an overview of trends in research findings as well as current assumptions about the interplay between environmental and genetic factors in the etiology of schizophrenia. Based on the cumulative findings, it appears that both genetic and prenatal factors can give rise to constitutional vulnerability. Subsequent neuromaturational processes, especially those that occur during adolescence, and exposure to stressful events can trigger the behavioral expression of this vulnerability.

Extensive scientific evidence indicates that reinforcement plays an important role in the genesis, maintenance, and recovery from substance use disorders. In this chapter, we review recent clinical research from laboratory, clinic, and naturalistic settings examining the role of reinforcement in substance use disorders. Well-controlled human laboratory studies are reviewed characterizing orderly interactions between the reinforcing effects of drugs and environmental context that have important implications for understanding risk factors for substance use disorders and for the development of efficacious interventions. Recent treatment-outcome studies on voucher-based contingency management and community reinforcement therapy are reviewed demonstrating how reinforcement and related principles can be used to improve outcomes across a wide range of different substance use disorders and populations. Overall, the chapter characterizes a vigorous area of clinical research that has much to contribute to a scientific analysis of substance use disorders.

Cigarette smoking is a leading cause of mortality and morbidity and a particularly common and intractable addictive disorder. Research shows that nicotine is a sine qua non of tobacco addiction and that it produces the hallmark effects of addictive drugs: sensitization, tolerance, physical dependence, and euphoria/elation. Research on the development of smoking reveals that although smoking prevalence has declined from a peak in the mid-1990s, close to 30% of twelfth graders still smoke. Smoking in adolescents is related to development of physical dependence, ethnicity, impulsivity, affective disorder, and peer influences. However, which of these exerts the greatest causal effects is unknown, and their influence no doubt varies across individuals and across development. Once dependence on tobacco smoking is established, evidence suggests that tobacco motivation is strongly influenced by a reduction in withdrawal symptoms, an expectation of stress reduction, and conditioned reinforcement. Nicotine motivation may also be influenced by modulation in stimulus incentive value.

Because of personal motives and the architecture of the mind, it may be difficult for people to know themselves. People often attempt to block out unwanted thoughts and feelings through conscious suppression and perhaps through unconscious repression, though whether such attempts are successful is controversial. A more common source of self-knowledge failure is the inaccessibility of much of the mind to consciousness, including mental processes involved in perception, motor learning, personality, attitudes, and self-esteem. Introspection cannot provide a direct pipeline to these mental processes, though some types of introspection may help people construct beneficial personal narratives. Other ways of increasing self-knowledge include looking at ourselves through the eyes of others and observing our own behavior. These approaches can potentially promote self-knowledge, although major obstacles exist. It is not always advantageous to hold self-perceptions that correspond perfectly with reality, but increasing awareness of nonconscious motives and personality is generally beneficial.

Gender is increasingly understood as defining a system of power relations embedded in other power relations. Psychological research on gender—which has most often focused on analysis of sex differences, within-sex variability, and gender roles—has begun to incorporate this new understanding. By drawing on three resources, psychologists can make more rapid progress in understanding gender's significance for psychological processes: social science theories that link the individual and social levels of analysis; constructs (such as identity) that bridge the social and individual levels; and conceptual tools generated in feminist theory, perhaps especially intersectionality. We review these resources, cite active research programs that have employed them, and conclude by offering some practical suggestions about how to incorporate these resources into our research.

Since the birth of the nation, concepts about the political duties of citizens have changed drastically to keep pace with growth and development. The information needs have changed as well, as have the institutions that supply this information. In this essay I analyze the interrelation between citizenship in the twenty-first century and the information supply that nourishes it. I focus on studies that explore how political news is shaped to attract public attention and how citizens select it and make sense of it. Evidence from content analyses, focus group data, and intensive interviews supports the conclusion that the news supply is adequate for citizens' civic needs and that they use it judiciously. To accept that conclusion requires abandoning outdated paradigms of citizenship that ignore information-processing capabilities of human beings, the basic motivations that drive the search for political information, and the impact of the ever-increasing complexity of politics.