Infants' understanding of object-directed action

When and in what ways do infants recognize humans as intentional actors? An important aspect of this larger question concerns when infants recognize specific human actions (e.g. a reach) as object-directed (i.e. as acting toward goal-objects). In two studies using a visual habituation technique, 12-month-old infants were tested to assess their recognition that an adult's reach is directed toward its target object. Infants in the experimental condition were habituated to a display in which an actor reached over a wall-like barrier with an arcing arm movement, to pick up a ball. After habituation infants saw two test displays, for which the barrier was removed. In the direct test event the actor reached directly for the ball, the arm tracing a visually new path, but the action consistent with attempting to reach for the object as directly as possible. In the indirect test event the actor traced the old path, reaching over in an arc, even though the wall was no longer present. This arm movement was identical to that in habituation but no longer displayed a reach going directly to its object. In a control condition infants saw the same movements but in a situation with no goal-object. In the experimental conditions, with a goal object present, infants looked longer at the indirect test event in comparison to the direct test event. In the control conditions infants looked equally at both indirect and direct test events. We conclude that sensitivity to human object-directed action is established by 12-month-olds and compare these results to recent findings by [Gergely, G., Nadasdy, Z., Csibra, G., & Biro S. (1995). Taking the intentional stance at 12 months of age. Cognition, 56, 165-193] and [Woodward, A. (1998). Infants selectively encode the goal object of an actor's reach. Cognition, 69, 1-34].     

Socioeconomic status and insomnia

This investigation compared the likelihood of insomnia and insomnia-related health consequences among individuals of different socioeconomic status. A random-digit dialing procedure was used to recruit at least 50 men and 50 women in each age decade from 20 to 80+ years old. Participants completed 2 weeks of sleep diaries as well as questionnaires related to fatigue, sleepiness, and psychological distress. Socioeconomic status was measured by education status assessed at 3 different levels: individual, household, and community. Results indicated that individuals of lower individual and household education were significantly more likely to experience insomnia even after researchers accounted for ethnicity, gender, and age. Additionally, individuals with fewer years of education, particularly those who had dropped out of high school, experienced greater subjective impairment because of their insomnia.     

Role rigidity: a problem of identity misclassification?

When nonstigmatized individuals enact certain role-violating behaviors, they risk becoming "falsely accused deviants" (H. S. Becker, 1963, p. 20). For instance, when heterosexual men perform stereotypically feminine behaviors, they are liable to get misclassified as homosexual. Findings presented here reveal that expectations of identity misclassification fuel nonstigmatized individuals' negative reactions to role violations (Studies 1-2) and that using a disclaimer--that is, informing their audience of their nonstigmatized identity--assuages people's discomfort during a role-violating behavior (Studies 3-4). Moreover, when not concerned about being misclassified, nonstigmatized individuals benefit psychologically from the enactment of a challenging role violation (Study 4). Discussion considers the nature of the threat that misclassified role violators face and compares the plight of the falsely accused deviant to that of the truly stigmatized individual.     

Affirmation of personal values buffers neuroendocrine and psychological stress responses

Stress is implicated in the development and progression of a broad array of mental and physical health disorders. Theory and research on the self suggest that self-affirming activities may buffer these adverse effects. This study experimentally investigated whether affirmations of personal values attenuate physiological and psychological stress responses. Eighty-five participants completed either a value-affirmation task or a control task prior to participating in a laboratory stress challenge. Participants who affirmed their values had significantly lower cortisol responses to stress, compared with control participants. Dispositional self-resources (e.g., trait self-esteem and optimism) moderated the relation between value affirmation and psychological stress responses, such that participants who had high self-resources and had affirmed personal values reported the least stress. These findings suggest that reflecting on personal values can keep neuroendocrine and psychological responses to stress at low levels. Implications for research on the self, stress processes, health, and interventions are discussed.     

A mixed-handed advantage in episodic memory: A possible role of interhemispheric interaction

Recent behavioral and brain imaging data indicate that performance on explicit tests of episodic memory is associated with interaction between the left and right cerebral hemispheres, in contrast with the unihemispheric basis for implicit tests of memory. In the present work, individual differences in strength of personal handedness were used as markers for differences in hemispheric communication, with mixed-handers inferred to have increased interhemispheric interaction relative to strong right-handers. In Experiment 1, memory for words was assessed via recall or word fragment completion. In Experiment 2, memory for real-world events was assessed via recall. Results supported the hypothesis, in that mixed-handers displayed better episodic memory in comparison with strong right-handers.     

A dynamic developmental theory of attention-deficit/hyperactivity disorder (ADHD) predominantly hyperactive/impulsive and combined subtypes

Attention-deficit/hyperactivity disorder (ADHD) is currently defined as a cognitive/behavioral developmental disorder where all clinical criteria are behavioral. Inattentiveness, overactivity, and impulsiveness are presently regarded as the main clinical symptoms. The dynamic developmental behavioral theory is based on the hypothesis that altered dopaminergic function plays a pivotal role by failing to modulate nondopaminergic (primarily glutamate and GABA) signal transmission appropriately. A hypofunctioning mesolimbic dopamine branch produces altered reinforcement of behavior and deficient extinction of previously reinforced behavior. This gives rise to delay aversion, development of hyperactivity in novel situations, impulsiveness, deficient sustained attention, increased behavioral variability, and failure to "inhibit" responses ("disinhibition"). A hypofunctioning mesocortical dopamine branch will cause attention response deficiencies (deficient orienting responses, impaired saccadic eye movements, and poorer attention responses toward a target) and poor behavioral planning (poor executive functions). A hypofunctioning nigrostriatal dopamine branch will cause impaired modulation of motor functions and deficient nondeclarative habit learning and memory. These impairments will give rise to apparent developmental delay, clumsiness, neurological "soft signs," and a "failure to inhibit" responses when quick reactions are required. Hypofunctioning dopamine branches represent the main individual predispositions in the present theory. The theory predicts that behavior and symptoms in ADHD result from the interplay between individual predispositions and the surroundings. The exact ADHD symptoms at a particular time in life will vary and be influenced by factors having positive or negative effects on symptom development. Altered or deficient learning and motor functions will produce special needs for optimal parenting and societal styles. Medication will to some degree normalize the underlying dopamine dysfunction and reduce the special needs of these children. The theory describes how individual predispositions interact with these conditions to produce behavioral, emotional, and cognitive effects that can turn into relatively stable behavioral patterns.     

Adolescent Suicidality: Who Will Ideate,Who Will Act?

Responses to the 1999 Youth Risk Behavior Survey including suicide ideation, attempt, medically treated attempt, and six problem behaviors were analysed. Youth across the spectrum ideated. Overwhelmingly, the 17% of youth with more than three problem behaviors were the youth who acted; they accounted for 60% of medically treated suicidal acts. Compared to adolescents with zero problem behaviors, the odds of a medically treated suicide attempt were 2.3 times greater among respondents with one, 8.8 with two, 18.3 with three, 30.8 with four, 50.0 with five, and 227.3 with six. A count of problem behaviors offers a reliable way to identify suicide risk.