Control of oscillatory force tasks: Low-frequency oscillations in force and muscle activity

Force variability during steady force tasks is strongly related to low-frequency oscillations (<0.25 Hz) in force. However, it is unknown whether low-frequency oscillations also contribute to the variability of oscillatory force tasks. To address this, twelve healthy young participants (21.08 ± 2.99 years, 6 females) performed a sinusoidal force task at 15% MVC at two different frequencies (0.5 and 1 Hz) with isometric abduction of the index finger. We recorded the force from the index finger and surface EMG from the first dorsal interosseous muscle and quantified the following outcomes: 1) trajectory variability and accuracy; 2) power spectrum of force and EMG bursting below 2 Hz; 3) power spectrum of the interference EMG from 4 to 60 Hz. The trajectory variability and error significantly increased from 0.5 to 1 Hz task (P < 0.01). Increased force oscillations <0.25 Hz contributed to greater trajectory variability and error for both the 0.5 and 1 Hz oscillatory task (R² > 0.33; P < 0.05). The <0.25 Hz oscillations in force were positively associated with greater power in the <0.25 Hz for EMG bursting (R² > 0.52; P < 0.01). The modulation of the interference EMG from 35 to 60 Hz was a good predictor of the <0.25 Hz force oscillations for both the 0.5 Hz task and 1 Hz task (R² > 0.66; P < 0.01). These results provide novel evidence that, similar to steady contractions, low-frequency oscillations of the motor neuron pool appear to be a significant mechanism that controls force during oscillatory force tasks.     

Temporal dynamics in attention bias: effects of sex differences,task timing parameters,and stimulus valence

New methods of calculating indices from the dot-probe task measure temporal dynamics in attention bias or fluctuations in attention bias towards and away from emotional stimuli over time. However, it is unclear how task-specific parameters such as stimulus valence and stimulus onset asynchrony (SOA) as well as participant sex affect temporal dynamics in attention bias. To address this, male and female participants (N?=?106) completed either a fearful or happy face dot-probe task with four levels of SOA (84?ms, 168?ms, 336?ms, and 672?ms). Results suggest that temporal dynamics in attention bias are (1) greatest at the longest SOA, (2) greater in females, and (3) insensitive to stimulus valence. These findings indicate that participant sex and task timing, but not stimulus valence, are related to temporal dynamics in attention bias and should be considered in future studies utilizing this approach.     

“I know you can do this” versus “How can you be so stupid?” Feedback among Chinese and American young adult friends

According to past research, young adults prefer positive feedback from their friends, but emotional reactions to negative feedback are less severe in Korea than in the United States. We extended this past work in several ways: We studied both giving and receiving feedback, recruited Chinese young adults, used realistic scenarios, and employed the situation‐sampling method. Using text‐message‐based vignettes, Study 1 found that both American and Chinese friends used happy emojis when exchanging positive feedback whereas Americans used less positive emojis than did the Chinese when exchanging negative feedback. We then collected actual examples of feedback that people had given to their friends (Study 2a) and showed them to new samples of Chinese and American young adults (Study 2b). This situation‐sampling methodology found that (a) Americans rated negative feedback from both cultures especially negatively, and (b) negative feedback examples from China were rated especially negatively by people in both cultures. That is, although Chinese negative feedback is seemingly more harsh, Chinese young adults do not react as negatively.     

中国成年人认知风格调查报告*

应用《心理健康素质测评系统·中国成年人认知风格问卷》对全国23个省、市、自治区的6432名成年人的认知风格进行了调查。结果发现:中国成年人的认知风格总体水平较好。比较不同人口学特征的成年人在认知风格各维度上的差异发现:(1)女性在灾难化维度上得分显著高于男性;(2)随着年龄的增长,成年人的认知风格总均分及各维度得分均呈上升趋势;(3)农村成年人认知风格总均分及各维度得分显著高于城市成年人;(4)随着受教育程度的提高,成年人的认知风格总均分及各维度得分呈下降趋势;(5)年龄段与受教育程度在选择性提取维度上存在交互作用,其中初中文化程度的老年组被试得分最高。     

项目反应时间的对数偏正态模型

近年来,项目反应时间数据的建模是心理和教育测量领域的热门方向之一。针对反应时间的对数正态模型和Box-Cox正态模型的不足,本文在van der Linden的分层模型框架下基于偏正态分布建立一个反应时间的对数线性模型,并成功给出模型参数估计的马尔科夫链蒙特卡罗（Markov Chain Monte Carlo, MCMC）算法。模拟研究和实例分析的结果均表明,与对数正态模型和Box-Cox正态模型相比,对数偏正态模型表现出更加优良的拟合效果,具有更强的灵活性和适用性。     

Behavioral variability as avoidance behavior

This study aimed to investigate whether variable patterns of responses can be acquired and maintained by negative reinforcement under an avoidance contingency. Six male Wistar rats were exposed to sessions in which behavioral variability was reinforced according to a Lag contingency: Sequences of three responses on two levers had to differ from one, two or three previous sequences for shocks to be avoided (Lag 1, Lag 2 and Lag 3, respectively). Performance under the Lag conditions was compared with performance on a Yoke condition in which the animals received the same reinforcement frequency and distribution as in the Lag condition but behavioral variability was not required. The results showed that most of the subjects varied their sequences under the Lag contingencies, avoiding shocks with relatively high probability (≥ 0.7). Under the Yoke procedure, responding continued to occur with high probability, but the behavioral variability decreased. These results suggest that behavioral variability can be negatively reinforced.     

A country-wide probability sample of public attitudes toward stuttering in Portugal

BackgroundNegative public attitudes toward stuttering have been widely reported, although differences among countries and regions exist. Clear reasons for these differences remain obscure.PurposePublished research is unavailable on public attitudes toward stuttering in Portugal as well as a representative sample that explores stuttering attitudes in an entire country. This study sought to (a) determine the feasibility of a country-wide probability sampling scheme to measure public stuttering attitudes in Portugal using a standard instrument (the Public Opinion Survey of Human Attributes–Stuttering [POSHA–S]) and (b) identify demographic variables that predict Portuguese attitudes.MethodsThe POSHA–S was translated to European Portuguese through a five-step process. Thereafter, a local administrative office-based, three-stage, cluster, probability sampling scheme was carried out to obtain 311 adult respondents who filled out the questionnaire.ResultsThe Portuguese population held stuttering attitudes that were generally within the average range of those observed from numerous previous POSHA–S samples. Demographic variables that predicted more versus less positive stuttering attitudes were respondents’ age, region of the country, years of school completed, working situation, and number of languages spoken. Non-predicting variables were respondents’ sex, marital status, and parental status.ConclusionA local administrative office-based, probability sampling scheme generated a respondent profile similar to census data and indicated that Portuguese attitudes are generally typical.     

Prospective memory and intraindividual variability in ongoing task response times in an adult lifespan sample: the role of cue focality

To contribute to the ongoing conceptual debate of what traditional mean-level ongoing task (OT) costs tell us about the attentional processes underlying prospective memory (PM), we investigated costs to intraindividual variability (IIV) in OT response times as a potentially sensitive indicator of attentional processes. Particularly, we tested whether IIV in OT responses may reflect controlled employment of attentional processes versus lapses of controlled attention, whether these processes differ across adulthood, and whether it is moderated by cue focality. We assessed 150 individuals (19–82 years) in a focal and a nonfocal PM condition. In addition, external measures of inhibition and working memory were assessed. In line with the predictions of the lapses-of-attention/inefficient-executive-control account, our data support the view that costs to IIV in OT trials of PM tasks reflect fluctuations in the efficiency of executive functioning, which was related to failures in prospective remembering, particularly in nonfocal PM tasks, potentially due to their increased executive demands. The additional value of considering costs to IIV over and beyond traditional mean-level OT costs in PM research is discussed.     

What did you have in mind? Examining the content of intentional and unintentional types of mind wandering

It has recently been argued that researchers should distinguish between mind wandering (MW) that is engaged with and without intention. Supporting this argument, studies have found that intentional and unintentional MW have behavioral/neural differences, and that they are differentially associated with certain variables of theoretical interest. Although there have been considerable inroads made into the distinction between intentional/unintentional MW, possible differences in their content remain unexplored. To determine whether these two types of MW differ in content, we had participants complete a task during which they categorized their MW as intentional or unintentional, and then provided responses to questions about the content of their MW. Results indicated that intentional MW was more frequently rated as being future-oriented and less vague than unintentional MW. These findings shed light on the nature of intentional and unintentional MW and provide support for the argument that researchers should distinguish between intentional and unintentional types.     

Speech rhythm alterations in Spanish-speaking individuals with Alzheimer’s disease

Rhythm is the speech property related to the temporal organization of sounds. Considerable evidence is now available for suggesting that dementia of Alzheimer’s type is associated with impairments in speech rhythm. The aim of this study is to assess the use of an automatic computerized system for measuring speech rhythm characteristics in an oral reading task performed by 45 patients with Alzheimer’s disease (AD) compared with those same characteristics among 82 healthy older adults without a diagnosis of dementia, and matched by age, sex and cultural background. Ranges of rhythmic-metric and clinical measurements were applied. The results show rhythmic differences between the groups, with higher variability of syllabic intervals in AD patients. Signal processing algorithms applied to oral reading recordings prove to be capable of differentiating between AD patients and older adults without dementia with an accuracy of 87% (specificity 81.7%, sensitivity 82.2%), based on the standard deviation of the duration of syllabic intervals. Experimental results show that the syllabic variability measurements extracted from the speech signal can be used to distinguish between older adults without a diagnosis of dementia and those with AD, and may be useful as a tool for the objective study and quantification of speech deficits in AD.