Variant BDNF (Val66Met) impact on brain structure and function

Neurotrophins, such as brain-derived neurotrophic factor (BDNF), are a unique family of polypeptide growth factors that influence differentiation and survival of neurons in the developing nervous system. In adults, BDNF is important in regulating synaptic plasticity and connectivity in the brain. Recently, a common single-nucleotide polymorphism in the human BDNF gene, resulting in a valine to methionine substitution in the prodomain (Val66Met), has been shown to lead to memory impairment and susceptibility to neuropsychiatric disorders. An understanding of how this naturally occurring polymorphism affects behavior, anatomy, and cognition in adults is an important first step in linking genetic alterations in the neurotrophin system to definable biological outcomes in humans. We review the recent literature linking this BDNF polymorphism to cognitive impairment in the context of in vitro and transgenic animal studies that have established BDNF’s central role in neuronal functioning in the adult brain.     

The effects of self-focused rumination on global negative self-judgements in depression

Previous research in dysphoric participants has found that compared with distraction, rumination inductions are associated with increased levels of cognitive distortions and overgeneral autobiographical memories. Watkins and Teasdale ((2001) Journal of Abnormal Psychology, 110, 353–357) investigated which component of rumination was responsible for this effect in overgeneral memory, and found two distinct modes of ruminative self-focus, with analytical, evaluative self-focus maintaining overgeneral memory, whereas self-focus low in analytical thinking reduced overgeneral memory. The present study compared the effects of these two distinct forms of self-focused rumination with another measure of overgeneral thinking—global negative self-judgements. Thirty depressed participants and thirty never-depressed participants were randomly allocated to ‘analytic’ (high analysis) or ‘experiential’ (low analysis) self-focused manipulations. As predicted, in depressed participants, the analytical self-focus condition increased ratings of the self as worthless and incompetent pre- to post-manipulation, whereas the experiential self-focus condition resulted in no significant change in such judgements. The results are consistent with the hypothesis that an analytical mode of self-focused rumination may be particularly maladaptive in depression.     

Extrinsic cognitive load impairs low-level speech perception

Recent research has suggested that the extrinsic cognitive load generated by performing a nonlinguistic visual task while perceiving speech increases listeners’ reliance on lexical knowledge and decreases their capacity to perceive phonetic detail. In the present study, we asked whether this effect is accounted for better at a lexical or a sublexical level. The former would imply that cognitive load directly affects lexical activation but not perceptual sensitivity; the latter would imply that increased lexical reliance under cognitive load is only a secondary consequence of imprecise or incomplete phonetic encoding. Using the phoneme restoration paradigm, we showed that perceptual sensitivity decreases (i.e., phoneme restoration increases) almost linearly with the effort involved in the concurrent visual task. However, cognitive load had only a minimal effect on the contribution of lexical information to phoneme restoration. We concluded that the locus of extrinsic cognitive load on the speech system is perceptual rather than lexical. Mechanisms by which cognitive load increases tolerance to acoustic imprecision and broadens phonemic categories were discussed.     

Women are more sensitive than men to prior trial events on the Stop‐signal task

Sexual dimorphism in the brain and cognition is a topic of widespread interest. Many studies of sex differences have focused on visuospatial and verbal abilities, but few studies have investigated sex differences in executive functions. We examined two key components of executive function – response inhibition and response monitoring – in healthy men (n = 285) and women (n = 346) performing the Stop‐signal task. In this task, participants are required to make a key press to a stimulus, unless a tone is presented at some delay following the initial stimulus presentation; on these infrequent trials, participants are instructed to inhibit their planned response. Response inhibition was assessed with an estimate of the latency needed to inhibit a response (stop‐signal reaction time), and response monitoring was measured by calculating the degree to which participants adjusted their reaction times based on the immediately preceding trial (e.g., speeding following correct trials and slowing following errors). There were no sex differences in overall accuracy or response inhibition, but women showed greater sensitivity to trial history. Women sped up more than men following correct ‘Go’ trials, and slowed down more than men following errors. These small but statistically significant effects (Cohen's d = 0.25–0.3) suggest more flexible adjustments in speed–accuracy trade‐offs in women and greater cognitive flexibility associated with the responsive control of action.     

Understanding Humility and Its Role in Relational Therapy

Humility is a character trait and virtue that has received scant attention in psychotherapy literature. A panel of experts was assembled to confer on their beliefs about humility for this Delphi study. They responded to a proposed definition of humility and provided a variety of statements regarding the role of humility in client change and relational therapy in general. The results suggest that key elements of change that occur during the process of relational therapy (including certain “common factors”) seem to be related to humility. Also, humility’s unique relationship to self and other suggests it is often at work in relational change. The authors propose further exploration of humility and its role as a pre-cursor to client change efforts. Humility’s role in the Transtheoretical Model of Change is hypothesized and future directions for theory and research are suggested.     

Home behavioral economics: Childcare decisions in the United States and Norway

This research investigated how a couple decides which parent stays home as a childcare provider by attempting to determine the economic value on maternal care versus paternal care while examining the potential effects of nationality, gender role attitudes, and social support. We collected data from 240 American participants and 250 Norwegian participants who were asked to decide how much a mother needs to earn to allow her husband to stay at home to provide childcare and how much a father needs to earn to allow his wife to stay at home and provide childcare, in addition to items assessing gender role attitudes. No effect of social support was found, but Norwegians were slightly more likely than Americans to place a heavier earning burden on the husband. There were few differences in gender role attitudes by nationality. The impact of public policy and social desirability on the results and childcare decision making are discussed.