Psychological stress and glucose metabolism in obese and normal-weight subjects: a possible mechanism for differences in stress-induced eating

Acute psychological stress has been found to impair the handling of a glucose load in normal-weight individuals and to produce a delay in gastrointestinal transit time. The present study utilized the same paradigm to compare 10 obese and 10 normal-weight subjects. All subjects participated in two counterbalanced sessions (stress and nonstress). At each session, subjects were fed a carbohydrate load, and glucose was measured 0, 30, 60, 90, and 120 min after the load. On nonstress days, subjects relaxed after the drink; on stress days, subjects participated in 30 min of competitive tasks. The stressor significantly delayed the glucose response in the normal-weight subjects but did not affect the glucose response in obese subjects. This finding may have implications for differences between obese and normal-weight individuals in stress-induced eating, possibly explaining the decreased consumption of normal-weight individuals during stress.     

Can dancers suppress the haptically mediated interpersonal entrainment during rhythmic sway?

Interpersonal entrainment emerges spontaneously when partners performing rhythmic movements together exchange sensory feedback about the other's movements. In this study, we asked whether couples of expert dancers, non-dancers and mixed couples can suppress the spontaneous haptically mediated inter-personal entrainment when their rhythmic sway is paced by differing metronome tempos. Fifty-four young participants formed three types of couples: nine dancer couples, consisting of individuals with at least eight years systematic practice in traditional Greek dance; nine non-dancer couples, consisting of individuals with no prior experience in dance and nine mixed couples, consisting of one dancer and one novice partner. Partners swayed rhythmically for 60 s, at different pacing frequencies (one at 0.25 Hz and the other at 0.35 Hz) under three haptic contact conditions: no contact between them; light fingertip touch established in the 2nd trial segment (30 s); and light fingertip touch released in the 2nd trial segment (30 s). Spectral analysis of the antero-posterior center of pressure displacement revealed that light touch increased the deviation of the dominant from the target (pacing) sway frequency, decreased the proportion of the signal's power at the target frequency and increased the coherence between the partners' sway signals (inter-personal coherence). These effects were specific to the mixed group whereas touch interference was weaker in non-dancers and absent in dancers. In addition, the coherence between the trial segments (intra-personal coherence) significantly decreased with touch only for the non-dancer while it remained unchanged for the dancer partner of the mixed group suggesting that the dancer was leading the non-dancer partner. It is concluded that systematic practice with traditional dance can modulate the spontaneous tendency towards haptically mediated interpersonal entrainment.     

Neural mechanisms underlying subsequent memory for personal beliefs:An fMRI study

Many fMRI studies have examined the neural mechanisms supporting emotional memory for stimuli that generate emotion rather automatically (e.g., a picture of a dangerous animal or of appetizing food). However, far fewer studies have examined how memory is influenced by emotion related to social and political issues (e.g., a proposal for large changes in taxation policy), which clearly vary across individuals. In order to investigate the neural substrates of affective and mnemonic processes associated with personal opinions, we employed an fMRI task wherein participants rated the intensity of agreement/disagreement to sociopolitical belief statements paired with neural face pictures. Following the rating phase, participants performed an associative recognition test in which they distinguished identical versus recombined face–statement pairs. The study yielded three main findings: behaviorally, the intensity of agreement ratings was linked to greater subjective emotional arousal as well as enhanced high-confidence subsequent memory. Neurally, statements that elicited strong (vs. weak) agreement or disagreement were associated with greater activation of the amygdala. Finally, a subsequent memory analysis showed that the behavioral memory advantage for statements generating stronger ratings was dependent on the medial prefrontal cortex (mPFC). Together, these results both underscore consistencies in neural systems supporting emotional arousal and suggest a modulation of arousal-related encoding mechanisms when emotion is contingent on referencing personal beliefs.     

The coupling of short sleep duration and high sleep need predicts riskier decision making

Abstract

Objective: To examine how risk-related decision making might be associated with habitual sleep variables, including sleep variability, sleep duration and perceived sleep need in young adults cross-sectionally and longitudinally.

Design: 166 participants completed a 7-day protocol with sleep and risk-related decision-making measures at baseline (T1) and 12 months later (T2).

Results: Habitual short sleep duration (averaging < 6?h nightly) was identified in 11.0% in our sample. After controlling for baseline demographic factors and risk-taking measures, self-reported sleep need at T1 interacted with habitual short sleep in predicting risk taking at follow-up (F_8,139=9.575, adjusted R²=.431, p<.001). T1 greater perceived sleep need predicted more risk taking among short sleepers, but decreased risk taking among normal sleepers at T2. Variable sleep timing was cross-sectionally correlated with making more Risky choices at baseline and fewer Safe choices after loss at follow up.

Conclusions: Young adults with variable sleep timing and those with short sleep duration coupled with high perceived sleep need were more likely to take risks. The moderating effects of perceived sleep need suggest that individual differences may alter the impact of sleep loss and hence should be measured and accounted for in future studies.     

Effects of Weight and Syntactic Priming on the Production of Cantonese Verb-Doubling

Verb-doubling, where a copy of the main verb occurs both before and after the direct object, is a structure commonly used in Chinese in sentences containing a frequency or duration phrase. In Cantonese, verb-doubling is highly optional and therefore problematic for existing syntactic, semantic, and pragmatic accounts of its distribution in Mandarin. The current study investigates the role of grammatical weight and syntactic priming in the choice of verb-doubling in Cantonese. Following (Hawkins in Efficiency and complexity in grammars, Oxford University Press, Oxford, 2004) theory of efficiency and complexity in grammars, we hypothesized that speakers would choose verb-doubling over the canonical structure more often when the object NP was heavy, in order to minimize processing domains. In addition, we expected an effect of syntactic priming whereby the choice of structure is influenced by a previously encountered structure. The results of two elicited production experiments revealed no weight-based preference for verb-doubling, and only minor effects of grammatical weight, but clear effects of syntactic priming: (1) for both canonical primes and verb-doubling primes, speakers tended to repeat previously heard structures; (2) the priming effect was just as strong in the heavy NP condition, where speakers made more errors recalling the semantic content of the sentence, suggesting that semantic information is represented separately from syntactic information; (3) the priming effect was stronger for informationally accurate responses, suggesting that recently activated structures are easier to produce than other structures under conditions of increased cognitive load. We conclude that the choice between verb-doubling and canonical structure in Cantonese is easily influenced by the structure of recently encountered sentences, with weight effects, if any, being more difficult to detect.     

Timing and aging: slowing of fastest regular tapping rate with preserved timing error detection and correction

This study assessed motor limits of regular tapping, timing error detection, and correction in 60 participants aged from 19 to 98 years. Rate limitations on motor production were estimated from the average inter-tap interval when tapping as fast as possible for 30 s. Timing error detection required participants to judge whether a sound sequence presented at a slow, intermediate, or fast speed contained an irregularity because of phase shift. This was performed with or without synchronizing to the sounds. On the basis of the just-detectable positive phase shift (JND), participants synchronized with sequences containing phase shifts that were subliminal, just detectable or supraliminal. On average, JNDs were 9% of the inter-onset interval and by and large were not affected by synchronization tapping. Speed of error correction was estimated from the number of tones to return within 20% of the preshift synchronization error. Consistent with previous findings of motor slowing with aging, the fastest inter-tap interval increased with age. However, there was no age-related decline in JNDs or speed of error correction, both of which reflect predictive abilities for intervals within the motor repertoire of human adults. These results point towards intact timing error processing up to an advanced age. In assessing timing abilities in the brain of older adults, it is important to differentiate between motor slowing and its impact on rhythmic behavior (e.g., walking pace) from anticipatory mechanisms ('what to expect when') and how these are used to adjust the timing of actions ('what to do when').     

Developing equivalent Chinese and English scale‐point labels for rating scales used in survey research

Rating scales are the most frequently‐used response tool in surveys, and the scale levels are commonly described with words [verbal scale‐point labels (VSPL)]. In this study, Chinese VSPL were identified which employ five‐point scales that are psychometrically equivalent to English VSPL. In several bilingual studies, a total of 61 Chinese and 44 English items addressing intensity, frequency, and agreement rating modalities were tested. For each VSPL, three aspects were measured: position between minimum and maximum, familiarity, and appeal. The correspondence between pertinent Chinese and English words was also assessed. Based on these findings, we recommend specific VSPL that are best‐suited for achieving equivalence between Chinese and English in rating scales.     

Training in Mindful Caregiving Transfers to Parent–Child Interactions

In an earlier study, we provided mindfulness training to three caregivers of individuals with profound multiple disabilities. We measured levels of happiness displayed by the individuals during the 8 weeks of mindfulness training of the caregivers, as well as during the 16 weeks following the termination of training. We found that happiness increased markedly when an individual interacted with a caregiver who had received training in mindfulness as opposed to a control caregiver who did not receive such training. In this study, we investigated whether the increased mindfulness of the three caregivers would transfer to interactions with their own children. The children’s non-compliance with their mother’s requests was used as an indirect index of the effects of training their mothers received in mindfulness. Although the ages of the children and their baseline levels of non-compliance were variable, the data showed a decrease in non-compliance during mindfulness training of the caregivers and further decreases following the completion of training. Our data provide preliminary evidence of transfer of mindfulness training from caregiving to parent–child interactions. We speculate as to why this may occur in mindfulness training.     

Ouch! – a logotherapeutic discourse of butch and tattooed in China

• This is a study of a small group of self‐identified butch lesbians in their consumption of tattoos. The emotion‐laden experience of negotiating social symbolism and self‐identity (Elliott, 1997 ) in the context of hyperrealism (Baudrillard, 1983 ) has given rise to what Frankl ( 1984 ) has described as “existential vacuums.” Frankl suggested that these “existential vacuums” can be filled with a higher level of meaning. An artifact of consumption, the tattoo, is used by the informants in this study as a component of bricolage in the DIY process of constructing a new self (Elliott, 1997 ), with the entire process of being tattooed – particularly the hyper‐stimulation and pain of the procedure – further “existentializing” a new existence of “imagined masculinity.” This new existence that transcends suffering and assigns new meaning to life is the principle idea of Frankl's logotherapy (Frankl, 1984 ; Barnes, 2000 ; Blair, 2004 ).

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