Epigenetics in the mature mammalian brain: effects on behavior and synaptic transmission

The role of epigenetic mechanisms in control of gene expression during mammalian development is well established. Associations between specific DNA or histone modifications and numerous neurodevelopmental and neurodegenerative disorders implies significant consequences of epigenetic dysregulation in both the developing and mature brain, the latter of which is the general focus of this review. Accumulating evidence suggests that epigenetic changes are involved in normal cognitive processes in addition to neurological and psychiatric disorders. Recent investigations into the regulation of epigenetic modifications in the adult brain have revealed novel and surprisingly dynamic mechanisms for controlling learning and memory-related behaviors as well as long-term synaptic plasticity. DNA methylation and histone acetylation have also been implicated in the modulation of basal synaptic transmission and the balance between excitation and inhibition in various brain regions. Studies have begun to uncover some of the alterations in gene expression that appear to mediate many of these effects, but an understanding of the precise mechanisms involved is still lacking. Nevertheless, the fundamental importance of epigenetic processes in influencing neuronal activity is becoming increasingly evident.     

Defense attorneys' concerns about the competence of adolescent defendants

Research indicates that a sizable proportion of adolescent defendants have difficulty understanding and participating in legal proceedings against them, and may be incompetent to stand trial. To examine attorneys' experience in defending adolescents with competence‐related difficulties, 214 juvenile attorneys were surveyed. Findings indicated that attorneys have doubts about the competence of approximately 10% of adolescent defendants, and that they find these cases particularly challenging to defend. Most attorneys appear to recognize that developmental factors may contribute to adolescents' competence‐related difficulties, and believe that the law should accept developmental immaturity as a basis for incompetence findings. In approximately half of the cases in which attorneys had doubts about competence, attorneys did not request a competence evaluation but instead made other efforts to address competence issues, such as by teaching adolescents about legal proceedings and further involving their parents. The implications of these findings are discussed. Copyright © 2010 John Wiley & Sons, Ltd.     

Response Conflict and Affective Responses in the Control and Expression of Race Bias

Models of racial attitudes traditionally have assumed that individual differences in the strength of underlying, 'implicit' associations between racial categories and stereotypical traits are the primary determinant of the expression of race bias. Thus, individual differences in performance on laboratory tasks designed to assess implicit race bias tend to be interpreted in terms of association strength. Here, we argue that such associations tell only part of the story, and probably the least interesting part. We posit that response conflict and its regulation are critical to understanding the need for control, and that affect-related processes help to determine the extent to which control resources will be implemented to overcome biased associations. We present data from a number of recent behavioral and psychophysiological studies in support of this idea, as well as conceptual accounts that point toward a model of race bias regulation that depends upon processes identified as important for regulation of thought, affect and action more generally.     

Stepping up the pressure: arousal can be associated with a reduction in male aggression

The attentional myopia model of behavioral control [Mann and Ward, 2007] was tested in an experiment investigating the relationship between physiological arousal and aggression. Drawing on previous work linking arousal and narrowed attentional focus, the model predicts that arousal will lead to behavior that is relatively disinhibited in situations in which promoting pressures to aggress are highly salient. In situations in which inhibitory pressures are more salient, the model predicts behavior that is relatively restrained. In the experiment, 81 male undergraduates delivered noise-blasts against a provoking confederate while experiencing either high or low levels of physiological arousal and, at the same time, being exposed to cues that served either to promote or inhibit aggression. In addition to supporting the predictions of the model, this experiment provided some of the first evidence for enhanced control of aggression under conditions of heightened physiological arousal. Implications for interventions designed to reduce aggression are discussed.     

Children’s Affect Expression and Frontal EEG Asymmetry: Transactional Associations with Mothers’ Depressive Symptoms

Although parents and children are thought to influence one another's affect and behavior, few studies have examined the direction of effects from children to parents, particularly with respect to parental psychopathology. We tested the hypothesis that children's affective characteristics are associated with the course of mothers' depressive symptoms. Children's affect expression was observed during a series of mother-child interaction tasks, and children's resting frontal electroencephalogram (EEG) asymmetry was assessed in a psychophysiology laboratory. Mothers' depressive symptoms were assessed at two time points, approximately one year apart, at the mother-child interaction visits. Depressive symptoms increased over time for mothers with a history of childhood-onset depression whose children exhibited right frontal EEG asymmetry. Depressive symptoms were associated with high child negative affect at both time points for mothers whose children exhibited right frontal EEG asymmetry. Cross-lagged models with a subset of participants provided some evidence of both parent-to-child and child-to-parent directions of effects. Findings suggest that akin to other interpersonal stressors, children's affective characteristics may contribute to maternal depressive symptoms.     

Visual identity and uncertainty in repetition blindness

Repetition blindness (RB) was investigated in 6 experiments. In the first 3 experiments participants detected vowel targets in 11-letter sequences. When all letters were uppercase, detection was poorer for same (e.g., AA) than for different (e.g., AO) targets. However, when one target was uppercase and the other lowercase, RB was found only for targets visually identical except for size (e.g., Oo), not for visually different pairs (e.g., Aa). Experiment 4 found RB for visually identical versus different consonant-vowel-consonant words. Experiments 5 and 6 replicated Kanwisher's (1987) experiment in which RB was insensitive to word case but revealed these effects to be artifacts of poor recognition of 5-letter words coupled with a biased guessing strategy. Overall, these experiments found RB only at a low level of visual information processing.     

Preschoolers' perspective taking in word learning: do they blindly follow eye gaze?

When learning new words, do children use a speaker's eye gaze because it reveals referential intent? We conducted two experiments that addressed this question. In Experiment 1, the experimenter left while two novel objects were placed where the child could see both, but the experimenter would be able to see only one. The experimenter returned, looked directly at the mutually visible object, and said either, "There's the [novel word]!" or "Where's the [novel word]?" Two- through 4-year-olds selected the target of the speaker's gaze more often on there trials than on where trials, although only the older children identified the referent correctly at above-chance levels on trials of both types. In Experiment 2, the experimenter placed a novel object where only the child could see it and left while the second object was similarly hidden. When she returned and asked, "Where's the [novel word]?" 2- through 4-year-olds chose the second object at above-chance levels. Preschoolers do not blindly follow gaze, but consider the linguistic and pragmatic context when learning a new word.     

The effects of choice on intrinsic motivation and related outcomes: a meta-analysis of research findings

A meta-analysis of 41 studies examined the effect of choice on intrinsic motivation and related outcomes in a variety of settings with both child and adult samples. Results indicated that providing choice enhanced intrinsic motivation, effort, task performance, and perceived competence, among other outcomes. Moderator tests revealed the effect of choice on intrinsic motivation was stronger (a) for instructionally irrelevant choices compared to choices made between activities, versions of a task, rewards, and instructionally relevant options, (b) when 2 to 4 successive choices were given, (c) when rewards were not given after the choice manipulation, (d) when participants given choice were compared to the most controlling forms of control groups, (e) for children compared to adults, (f) for designs that yoked choice and control conditions compared to matched designs in which choice was reduced or designs in which nonyoked, nonmatched controls were used, and (g) when the experiment was conducted in a laboratory embedded in a natural setting. Implications for future research and applications to real-world settings are discussed.     

Support for Returning to Work for a Patient of Social Behavior Disorder with Impaired Self-awareness

Social behavioral disorders and impaired self-awareness, which are sequelae of brain injuries, have negative effects on interpersonal relationships and employment. In this study, we performed a long-term client-centered approach to help the patient diagnosed with a social behavior disorder and impaired self-awareness return to work. Cognitive rehabilitation, cognitive-behavioral treatment, and positive behavioral support were provided while assessing the self-awareness using the Japanese version of the Self-Regulation Skills Interview. This patient exemplifies the importance of establishing methods for self-monitoring and rebuilding a positive self-identity while considering the complexities of self-awareness when helping patients with impaired self-awareness. The patient took the initiative in managing problematic behaviors due to social behavior disorder, and as a result, was able to achieve stable self-awareness. The strategies described in this patient can be used in the future to treat patients with social behavior disorder due to inadequate self-awareness. In order to practice a client-centered approach while assessing the patient's level of self-awareness, it is important to build a trusting relationship over a long period. To assess the level of self-awareness, existing interviews, questionnaires, and work to express one's mental and physical state as seen by the patient may be effective.

     

Medicare's search for effective obesity treatments: diets are not the answer

The prevalence of obesity and its associated health problems have increased sharply in the past 2 decades. New revisions to Medicare policy will allow funding for obesity treatments of proven efficacy. The authors review studies of the long-term outcomes of calorie-restricting diets to assess whether dieting is an effective treatment for obesity. These studies show that one third to two thirds of dieters regain more weight than they lost on their diets, and these studies likely underestimate the extent to which dieting is counterproductive because of several methodological problems, all of which bias the studies toward showing successful weight loss maintenance. In addition, the studies do not provide consistent evidence that dieting results in significant health improvements, regardless of weight change. In sum, there is little support for the notion that diets lead to lasting weight loss or health benefits.