scholarly journals Neural correlates of individual differences in circadian behaviour

2015 ◽  
Vol 282 (1810) ◽  
pp. 20150769 ◽  
Author(s):  
Jennifer A. Evans ◽  
Tanya L. Leise ◽  
Oscar Castanon-Cervantes ◽  
Alec J. Davidson
Keyword(s):  
Individual Differences ◽  
Ex Vivo ◽  
Neural Correlates ◽  
Entrainment Rate ◽  
Biological Clocks ◽  
Free Running ◽  
Central Pacemaker ◽  
Phase Heterogeneity ◽  
Insight Into

Daily rhythms in mammals are controlled by the circadian system, which is a collection of biological clocks regulated by a central pacemaker within the suprachiasmatic nucleus (SCN) of the anterior hypothalamus. Changes in SCN function have pronounced consequences for behaviour and physiology; however, few studies have examined whether individual differences in circadian behaviour reflect changes in SCN function. Here, PERIOD2::LUCIFERASE mice were exposed to a behavioural assay to characterize individual differences in baseline entrainment, rate of re-entrainment and free-running rhythms. SCN slices were then collected for ex vivo bioluminescence imaging to gain insight into how the properties of the SCN clock influence individual differences in behavioural rhythms. First, individual differences in the timing of locomotor activity rhythms were positively correlated with the timing of SCN rhythms. Second, slower adjustment during simulated jetlag was associated with a larger degree of phase heterogeneity among SCN neurons. Collectively, these findings highlight the role of the SCN network in determining individual differences in circadian behaviour. Furthermore, these results reveal novel ways that the network organization of the SCN influences plasticity at the behavioural level, and lend insight into potential interventions designed to modulate the rate of resynchronization during transmeridian travel and shift work.

Revealing the Role of Context, Experience and Individual Differences in the Assessment of Heroin Addicts’ Decision Making Abilities

2009 ◽  
Vol 24 (S1) ◽  
pp. 1-1
Author(s):  
C.G.J. Newman ◽  
I. Crome ◽  
M. Frisher
Keyword(s):  
Decision Making ◽  
Individual Differences ◽  
Substance Dependence ◽  
Task Design ◽  
Individual Response ◽  
Individual Data ◽  
Assessment And Treatment ◽  
Insight Into ◽  
Made In

The development of decision making paradigms has prompted a consideration that an underlying deficit may assist in explaining substance dependence. However, despite these advances, little progress has been made in accounting for large inter-subject variance within previous studies. This failure continues to undermine many of the previous attempts to explain individual difference.A study was undertaken to develop methods for analysing and describing individual response behaviours within a decision-making task. In addition, the effect of task manipulations such as feedback, penalties and practice were examined. Substitute medication maintained adults males were recruited for this study.Findings from this research offer new insight into a possible link between task design and the response behaviours exhibited. This study emphasised the importance of individual response behaviours, and the necessity to consider individual data as a route to understanding concepts drawn from between groups analysis. Significant issues are raised that might impact on other existing paradigms and implications are proposed in relation to the assessment and treatment of substance dependence.

scholarly journals Reduced VIP Expression Affects Circadian Clock Function in VIP-IRES-CRE Mice (JAX 010908)

2020 ◽  
Vol 35 (4) ◽  
pp. 340-352 ◽  
Author(s):  
Deborah A. M. Joye ◽  
Kayla E. Rohr ◽  
Danielle Keller ◽  
Thomas Inda ◽  
Adam Telega ◽  
...  
Keyword(s):  
Constant Darkness ◽  
Wild Type ◽  
Free Running ◽  
Dna Editing ◽  
Editing Enzyme ◽  
Free Running Period ◽  
Precise Role ◽  
Insight Into ◽  
Master Clock

Circadian rhythms are programmed by the suprachiasmatic nucleus (SCN), which relies on neuropeptide signaling to maintain daily timekeeping. Vasoactive intestinal polypeptide (VIP) is critical for SCN function, but the precise role of VIP neurons in SCN circuits is not fully established. To interrogate their contribution to SCN circuits, VIP neurons can be manipulated specifically using the DNA-editing enzyme Cre recombinase. Although the Cre transgene is assumed to be inert by itself, we find that VIP expression is reduced in both heterozygous and homozygous adult VIP-IRES-Cre mice (JAX 010908). Compared with wild-type mice, homozygous VIP-Cre mice display faster reentrainment and shorter free-running period but do not become arrhythmic in constant darkness. Consistent with this phenotype, homozygous VIP-Cre mice display intact SCN PER2::LUC rhythms, albeit with altered period and network organization. We present evidence that the ability to sustain molecular rhythms in the VIP-Cre SCN is not due to residual VIP signaling; rather, arginine vasopressin signaling helps to sustain SCN function at both intracellular and intercellular levels in this model. This work establishes that the VIP-IRES-Cre transgene interferes with VIP expression but that loss of VIP can be mitigated by other neuropeptide signals to help sustain SCN function. Our findings have implications for studies employing this transgenic model and provide novel insight into neuropeptide signals that sustain daily timekeeping in the master clock.

scholarly journals Quantifying individual differences in native and nonnative sentence processing

2020 ◽  
pp. 1-21
Author(s):  
Ian Cunnings ◽  
Hiroki Fujita
Keyword(s):  
Individual Differences ◽  
Sentence Processing ◽  
Reading Speed ◽  
Nonnative Speakers ◽  
Garden Path ◽  
Preliminary Examination ◽  
Reading Experiment ◽  
Nonnative Language ◽  
Insight Into

Abstract Research in sentence processing has increasingly examined the role of individual differences in language comprehension. In work on native and nonnative sentence processing, examining individual differences can contribute crucial insight into theoretical debates about the extent to which nativelike processing is possible in a nonnative language. Despite this increased interest in individual differences, whether commonly used psycholinguistic tasks can reliably measure individual differences between participants has not been systematically examined. As a preliminary examination of this issue in nonnative processing, we report a self-paced reading experiment on garden-path sentences in native and nonnative comprehension. At the group level we replicated previously observed findings in native and nonnative speakers. However, while we found that our self-paced reading experiment was a reliable way of assessing individual differences in overall reading speed and comprehension accuracy, it did not consistently measure individual differences in the size of garden-path effects in our sample (N = 64 native and 64 nonnative participants, and 24 experimental items). These results suggest that before individual differences in sentence processing can be meaningfully assessed, the question of whether commonly used tasks can consistently measure individual differences requires systematic examination.

scholarly journals Genetic and Environmental Influences on Individual Differences in Sleep Duration During Adolescence

2013 ◽  
Vol 16 (6) ◽  
pp. 1015-1025 ◽  
Author(s):  
Saskia J. te Velde ◽  
Niels van der Aa ◽  
Dorret I. Boomsma ◽  
Eus J. W. van Someren ◽  
Eco J. C. de Geus ◽  
...  
Keyword(s):  
Individual Differences ◽  
Environmental Factors ◽  
Sleep Duration ◽  
Substantial Part ◽  
Age Variation ◽  
Genetic And Environmental Factors ◽  
Adolescent Twins ◽  
Age Range ◽  
Insight Into

This study assessed to what extent genetic and environmental factors contributed to individual differences in adolescent sleep duration, and whether genetic and environmental contributions to sleep duration changed throughout adolescence. A twin-family design was used to gain insight into the genetic and environmental contributions to variation in sleep duration. The study sample consisted of 6,319 adolescent twins (44% males) and 1,359 non-twin siblings (44% males) in the age range of 12 to 20 years (mean age = 16.85,SD= 1.40). The participants self-reported usual sleep duration, which was categorized as less than 8 hours per night, 8–9 hours per night, and more than 9 hours per night. Results showed that the prevalence of shorter than optimum sleep duration, that is, less than 8 hours per night, was high, with the highest prevalence rates in later adolescence. The contribution of genetic and environmental factors to individual differences in sleep duration was dependent on age. Variation in sleep duration at the age of 12 years was accounted for by genetic (boys: 34%, girls: 36%), shared environmental (boys: 28%, girls: 45%), and non-shared environmental factors (boys: 38%, girls: 19%). At the age of 20 years, the role of genetic (boys: 47%, girls: 33%) and non-shared environmental factors (boys: 53%, girls: 67%) was more pronounced. It can be concluded from the results that individual differences in sleep duration were accounted for by genetic and non-shared environmental factors throughout adolescence, whereas shared environmental factors account for a substantial part of variation during early adolescence only.

Elaborating the role of reflection and individual differences in the study of folk-economic beliefs

2018 ◽  
Vol 41 ◽  
Author(s):  
Kevin Arceneaux
Keyword(s):  
Decision Making ◽  
Individual Differences ◽  
Cognitive Processes ◽  
Evolutionary History ◽  
Behavioral Responses ◽  
History Of ◽  
Economic Beliefs

AbstractIntuitions guide decision-making, and looking to the evolutionary history of humans illuminates why some behavioral responses are more intuitive than others. Yet a place remains for cognitive processes to second-guess intuitive responses – that is, to be reflective – and individual differences abound in automatic, intuitive processing as well.

The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito
Keyword(s):  
Antioxidant Capacity ◽  
Dietary Intervention ◽  
Ex Vivo ◽  
The Body ◽  
Dietary Polyphenols ◽  
Enzymatic Antioxidant ◽  
Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

Two Short Tests Fail to Detect Vigilance Decrements

2001 ◽  
Vol 17 (1) ◽  
pp. 48-55 ◽  
Author(s):  
Juan Botella ◽  
María José Contreras ◽  
Pei-Chun Shih ◽  
Víctor Rubio
Keyword(s):  
Individual Differences ◽  
High Performance ◽  
Selection Process ◽  
Vigilance Task ◽  
Air Traffic Controllers ◽  
Job Selection ◽  
Performance Deterioration ◽  
Short Test ◽  
Psychological Dimensions

Summary: Deterioration in performance associated with decreased ability to sustain attention may be found in long and tedious task sessions. The necessity for assessing a number of psychological dimensions in a single session often demands “short” tests capable of assessing individual differences in abilities such as vigilance and maintenance of high performance levels. In the present paper two tasks were selected as candidates for playing this role, the Abbreviated Vigilance Task (AVT) by Temple, Warm, Dember, LaGrange and Matthews (1996) and the Continuous Attention Test (CAT) by Tiplady (1992) . However, when applied to a sample of 829 candidates in a job-selection process for air-traffic controllers, neither of them showed discriminative capacity. In a second study, an extended version of the CAT was applied to a similar sample of 667 subjects, but also proved incapable of properly detecting individual differences. In short, at least in a selection context such as that studied here, neither of the tasks appeared appropriate for playing the role of a “short” test for discriminating individual differences in performance deterioration in sustained attention.

Individual Differences in the Name Similarity Effect

2014 ◽  
Vol 35 (2) ◽  
pp. 111-118
Author(s):  
Daniel J. Howard ◽  
Roger A. Kerin
Keyword(s):  
Individual Differences ◽  
Impression Management ◽  
Interactive Effect ◽  
Purchase Intentions ◽  
Brand Attitude ◽  
Self Monitoring ◽  
Similarity Effect ◽  
And Behavior ◽  
Usage Context

The name similarity effect is the tendency to like people, places, and things with names similar to our own. Although many researchers have examined name similarity effects on preferences and behavior, no research to date has examined whether individual differences exist in susceptibility to those effects. This research reports the results of two experiments that examine the role of self-monitoring in moderating name similarity effects. In the first experiment, name similarity effects on brand attitude and purchase intentions were found to be stronger for respondents high, rather than low, in self-monitoring. In the second experiment, the interactive effect observed in the first study was found to be especially true in a public (vs. private) usage context. These findings are consistent with theoretical expectations of name similarity effects as an expression of egotism manifested in the image and impression management concerns of high self-monitors.

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