The activity of the hypothalamo-neurohypophysial system in response to acute stressor exposure: neuroendocrine and electrophysiological observations

The present mini review focuses on stress-induced alterations of the electrical and secretory activity of vasopressin (AVP) and oxytocin (OXT) neurones originating within the supraoptic nucleus (SON) and constituting the hypothalamo-neurohypophysial system (HNS) in the male rat. Previously, it was thought that SON neurones are predominantly activated by osmotic and reproductive stimuli. However, recent findings also suggest a selective activation of AVP and/or OXT neurones in response to specific stressors. Inhibitory amino acids seem to participate at the level of the SON in the control of HNS activity during stress. Taurine, probably of glial origin, selectively inhibits the secretory activity of AVP neurones. In contrast, GABA, probably of neuronal origin, interferes with the release of OXT both from axon terminals into blood and from somata/dendrites into the extracellular fluid of the SON. Depending upon whether a defined stressor triggers taurine and/or GABA release within the SON the secretion of AVP and/or OXT from HNS neurones will be inhibited. These observations shed new light on the neurone-neurone and glial-neurone interactions that ensure an appropriate neuroendocrine stress response.     

Surveying a blank field with the attentional spotlight

Spatial localization is a unique aspect of selective attention that precedes and facilitates other aspects of sensory processing. A common model of spatial attention is an attentional spotlight that enlarges to fit attentional demands. It is unclear if this attentional spotlight expands to survey a blank field or to scan the spatial environment with a smaller attentional spotlight. Two tachistoscopic experiments with young adults investigated how attention is surveyed in a blank field. Exp. 1 consisted of single letters at two concentric regions and under different conditions of attentional demand. Reaction times were proportionally slower for stimuli occurring in a combination of the two regions located at different distances from the fixation point than for stimuli occurring in each region alone. This finding is not consistent with attentional spread to encompass the entire attentional field. The addition of more stimulus locations within each single region yielded significantly slower reaction times. Together these findings suggest that a small attentional spotlight serially monitors different regions of the visual field when there are anticipated locations to be attended.     

Temporal integration of speech prosody is shaped by language experience: an fMRI study

Differences in hemispheric functions underlying speech perception may be related to the size of temporal integration windows over which prosodic features (e.g., pitch) span in the speech signal. Chinese tone and intonation, both signaled by variations in pitch contours, span over shorter (local) and longer (global) temporal domains, respectively. This cross-linguistic (Chinese and English) study uses functional magnetic resonance imaging to show that pitch contours associated with tones are processed in the left hemisphere by Chinese listeners only, whereas pitch contours associated with intonation are processed predominantly in the right hemisphere. These findings argue against the view that all aspects of speech prosody are lateralized to the right hemisphere, and promote the idea that varying-sized temporal integration windows reflect a neurobiological adaptation to meet the 'prosodic needs' of a particular language.     

Mental pain and its relationship to suicidality and life meaning

Shneidman (1996) proposed that intense mental pain is related to suicide. Relatedly, Frankl (1963) argued that the loss of life's meaning is related to intense mental pain. The first goal of this research was to test Shneidman's proposition by comparing the mental pain of suicidal and nonsuicidal individuals. Meaning in life and optimism are the polar opposites of suicidality and hopelessness, and the examination of these variables in relation to mental pain was undertaken to provide a test of Frankl's proposition. In two studies, a relationship between a newly developed measure of mental pain--the Orbach & Mikulincer Mental Pain Scale, 2002 (OMMP; see also Orbach, Mikulincer, Sirota & Gilboa-Schechtman, 2002)--and suicidal behavior and life meaning were examined. Results confirmed both propositions. Implications for the study of mental pain and suicide are discussed.     

Does power magnify the expression of dispositions?

Conventional wisdom holds that power holders act more in line with their dispositions than do people who lack power. Drawing on principles of construct accessibility, we propose that this is the case only when no alternative constructs are activated. In three experiments, we assessed participants' chronic dispositions and subsequently manipulated participants' degree of power. Participants then either were or were not primed with alternative (i.e., inaccessible or counterdispositional) constructs. When no alternatives were activated, the responses of power holders--perceptions of other people (Experiment 1), preferences for charitable donations (Experiment 2), and strategies in an economic game (Experiment 3)--were more in line with their chronically accessible constructs than were the responses of low-power participants. However, when alternatives had been activated, power holders' responses were no longer more congruent with their dispositions than were the responses of low-power participants. We propose a single mechanism according to which power increases reliance on accessible constructs--that is, constructs that easily come to mind-regardless of whether these constructs are chronically or temporarily accessible.     

Differential trajectories of age-related changes in components of executive and memory processes

Several studies have demonstrated age-related declines in general executive function and memory. In this study, we examined cross-sectional and longitudinal age effects in more specific cognitive processes that constitute executive function and memory. We postulated that, whereas some components of executive and memory functions would show age differences and longitudinal declines, other specific abilities would be maintained or even improve with repeated testing. In a sample of individuals ≥55 years old from the Baltimore Longitudinal Study of Aging, we found longitudinal declines in inhibition, manipulation, semantic retrieval, phonological retrieval, switching, and long-term memory over a maximum of 14 years follow-up. In contrast, abstraction, capacity, chunking, discrimination, and short-term memory were maintained or even improved longitudinally, probably due in part to repeated testing. Moreover, whereas several different abilities were correlated across participants' cross-sectional performance, longitudinal changes in performance showed more heterogeneous trajectories. Finally, compared with cross-sectional performance, longitudinal trajectories showed better distinction between participants with and those without later cognitive impairment. These results show that longitudinal cognitive aging of executive and memory functions is not a uniform process but a heterogeneous one and suggest that certain executive and memory functions remain stable despite age-related declines in other component processes. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

The deviant citizen: Measuring potential positive relations between counterproductive work behaviour and organizational citizenship behaviour

Studies have shown a strong negative correlation between counterproductive work behaviour (CWB) and organizational citizenship behaviour (OCB), and opposite correlations with hypothesized antecedents. Such observed correlations may have been erroneously caused by three measurement artefacts: items measuring absence of CWBs, rather than behaviours that exceed requirements or expectations in OCB scales; supervisory halo; and agreement rather than frequency response format. A new OCB scale, the OCB‐checklist (OCB‐C) was used that did not have these artefacts. Contrary to prior expectations from the literature, positive relations were found between CWB and OCB, and stressors and OCB. Theoretical explanations for positive CWB/OCB relations (demand‐elicited OCB, social loafing, work process problems, rater perceptions and attributions, and aggravated job stress processes) are discussed.     

Would male conspicuous consumption capture the female eye? Menstrual cycle effects on women's attention to status products

In line with evolutionary principles of reproduction and mate selection, the current research shows that women's attention to status cues fluctuates across their menstrual cycle. Specifically, we show that women pay more attention to status products in a visual display around ovulation than in other phases of their menstrual cycle. Pill use eliminates these cycle phase effects. The results are discussed in relation to research on female mating goals and conspicuous consumption.     

Implicit Science Stereotypes Mediate the Relationship between Gender and Academic Participation

While the gender gap in mathematics and science has narrowed, men pursue these fields at a higher rate than women. In this study, 165 men and women at a university in the northeastern United States completed implicit and explicit measures of science stereotypes (association between male and science, relative to female and humanities), and gender identity (association between the concept “self” and one’s own gender, relative to the concept “other” and the other gender), and reported plans to pursue science-oriented and humanities-oriented academic programs and careers. Although men were more likely than women to plan to pursue science, this gap in students’ intentions was completely accounted for by implicit stereotypes. Moreover, implicit gender identity moderated the relationship between women’s stereotypes and their academic plans, such that implicit stereotypes only predicted plans for women who strongly implicitly identified as female. These findings illustrate how an understanding of implicit cognitions can illuminate between-group disparities as well as within-group variability in science pursuit.