Effects of mental stressors on mitogen induced lymphocyte responses in the laboratory

Abstract

There is considerable evidence from naturalistic studies that psychosocial stressors affect human immune function. To achieve control over factors that could bias naturalistic studies, laboratory stressors developed by cardiovascular researchers were tested to determine if they affected immune function. Thirty volunteer students were exposed to 20 minutes of mental tasks. Psychophysiological indices (heart rate, blood pressure, skin conductance) and subjective responses were monitored prior to, during, and 1-hour after the tasks, blood, samples for immunological analyses were also drawn at these times. Thirteen subjects who were not exposed to the tasks served as controls. Subjects exposed to the tasks showed increased levels of subjective distress and increased psychophysiologic responses (except diastolic blood pressure) during the tasks. Relative to controls, stressed subjects had reduced lymphocyte proliferative responses to classic T cell mitogens both immediately after and 1-hour after the tasks were found in whole blood cultures, although responses of isolated lymphocytes were not significantly affected. There were only marginal differences in whole blood mitogen responses for stressed subjects with low versus high autonomic reactions to the stressor. These results support an emerging view that the immune system is sensitive to brief stressors and that laboratory models may be useful for exploring stress-induced changes in immune function.     

Word Production and the Picture-Word Interference Paradigm: The Role of Learning

Psycholinguistic experiments conducted with the picture-word interference paradigm are typically preceded by a phase during which participants learn the words they will have to produce in the experiment. In Experiment 1, the pictures (e.g., a frog) were to be named and were presented with a categorically related (e.g., cat) or unrelated distracter (e.g., pen). In the related condition responses were slower relative to the unrelated condition for the participants who had gone through the learning phase. In contrast, participants who had not been previously familiarized with the materials showed facilitation. In Experiment 2 one group of participants, as usual, learned to produce the targets upon presentation of the corresponding pictures (e.g., a frog). The other group learned to produce the same targets upon presentation of unrelated pictures (e.g., a clock). They showed very similar semantic effects. The implications of the findings in the study of word production are discussed.     

Adapted to explore: Reinforcement learning in Autistic Spectrum Conditions

Recent studies have recorded a tendency of individuals with Autism Spectrum Conditions (ASC) to continually change their choices in repeated choice tasks. In the current study we examine if this finding implies that ASC individuals have a cognitive style that facilitates exploration and discovery. Six decision tasks were administered to adolescents with ASC and matched controls. Significant differences in shifting between choice options appeared in the Iowa Gambling task (Bechara, Damasio, Damasio, & Anderson, 1994). A formal cognitive modeling analysis demonstrated that for about half of the ASC participants the adaptation process did not conform to the standard reinforcement learning model. These individuals were only coarsely affected by choice-outcomes, and were more influenced by the exploratory value of choices, being attracted to previously un-explored alternatives. An examination of the five simpler decision tasks where the advantageous option was easier to determine showed no evidence of this pattern, suggesting that the shifting choice pattern is not an uncontrollable tendency independent of task outcomes. These findings suggest that ASC individuals have a unique adaptive learning style, which may be beneficial is some learning environment but maladaptive in others, particularly in social contexts.     

Do we map remembrances to the left/back and expectations to the right/front of a mental timeline? Space–time congruency effects with retrospective and prospective verbs

Recent experimental studies have shown that people code time in terms of a mental timeline which typically runs from left to right or from back to front. Determining the cognitive function of this mental timeline for language processing, however, is still an unsettled issue. Whereas the studies of Ulrich and Maienborn (2010) and Ulrich et al. (2012) argue against an automatic activation of the mental timeline for the interpretation of tense and temporal adverbials at sentence level, Sell and Kaschak (2011) observe an automatic activation for the processing of past- and future-related sentences in small stories. The present paper reports the results of three experiments which examine the processing of sentences with retrospective and prospective verbs (e.g., to remember, to regret vs. to expect, to announce) in present tense, which locate a second, embedded event in the past or the future. When temporal information was task-relevant, a space–time congruency effect emerged (Experiment 1). This suggests that the mental timeline is not only linked to overtly deictic linguistic material but may also be construed in a more intricate way through the compositional construction of sentence meaning. The congruency effect disappeared, however, when temporal information was task-irrelevant (Experiments 2 and 3), suggesting that the mental timeline is not functionally involved in the cognitive processing of these especially demanding two-event sentences. The results of the present study support the conclusion that the relevant factor driving an automatic activation of the mental timeline is not the number of linguistically expressed events, but might rather be the number of sentential units.     

The association between social isolation,loneliness and psychological problems in young adults: A study during the acute phase of COVID-19 in Italy

During the COVID-19 pandemic, governments had to impose social isolation measures to safeguard the citizens' health. However, this could have affected psychological problems. The aim of the present study was to investigate the psychological effects associated with social and emotional isolation during the acute phase of the COVID-19 in Italy. To this purpose, the degree of social isolation and loneliness and the presence of psychological problems (externalising and internalising) were investigated online in a sample of 395 young adults (18–30 years; 57% women). Results confirmed the relevant association between social isolation, loneliness and psychological problems, in both internalising and externalising dimensions. Particularly, loneliness showed the strongest association. Moreover, consistently with surveys conducted during the COVID-19-era, data highlighted that men were more vulnerable to social isolation and loneliness than women. These results underline the need for adequate interpersonal support during moments of isolation to prevent negative effects on psychological problems.     

Gestural acquisition in great apes: the Social Negotiation Hypothesis

Animal Cognition - Scientific interest in the acquisition of gestural signalling dates back to the heroic figure of Charles Darwin. More than a hundred years later, we still know relatively little...     

Identity motives underlying desired and feared possible future selves

Desired and feared possible future selves are important motivators of behavior and provide a temporal context for self-evaluation. Yet little research has examined why people desire some possible selves and fear others. In two studies, we tested the reflection of identity motives for self-esteem, efficacy, meaning, continuity, belonging, and distinctiveness in people's desired and feared possible future selves and in their possible future identity structures. As predicted, participants desired especially those possible futures in which motives for self-esteem, efficacy, meaning, and continuity would be satisfied, and they feared especially those in which the same four motives and, marginally, the motive for distinctiveness would be frustrated. Analyses supported an indirect path from belonging via self-esteem to desire and fear. Desired and feared possible future selves reflect potential satisfaction and frustration of these identity motives.     

Validity of a happiness Implicit Association Test as a measure of subjective well-being

The current study examined the validity of a happiness Implicit Association Test (IAT) as a measure of SWB. One hundred and fifty participants (75 pairs of friends) completed a newly developed happiness IAT and a standard self-esteem IAT. Participants also made self and informant ratings of life satisfaction and happy and sad affect. The results revealed convergent validity among the explicit measures, and among the implicit measures. Explicit–implicit correlations were lower. Self-ratings (.88) and informant ratings (.78) were more highly related with a common SWB factor than the implicit measures (.31). This finding suggests that implicit measures of well-being and happiness assess a different construct that overlaps only modestly with SWB. As a result, these implicit measures have limited utility to control for response styles in self-ratings of SWB.     

Comparison of automated procedures for ARMA model identification

This article evaluates the performance of three automated proceduresfor ARMA modelidentification commonly available in current versions of SAS for Windows: MINIC, SCAN, and ESACF. Monte Carlo experiments with different model structures, parameter values, and sample sizes were used to compare the methods. On average, the procedures either correctly identified the simulated structures or selected parsimonious nearly equivalent mathematical representations in at least 60% of the trials conducted. For autoregressive models, MINIC achieved the best results. SCAN was superior to the other two procedures for mixed structures. For moving-average processes, ESACF obtained the most correct selections. For all three methods, model identification was less accurate for low dependency than for medium or high dependency processes. The effect of sample size was more pronounced for MINIC than for SCAN and ESACE SCAN and ESACF tended to select higher-order mixed structures in larger samples. These findings are confined to stationary nonseasonal time series.