2,004 research outputs found
Noninvasive stimulation over the dorsolateral prefrontal cortex facilitates the inhibition of motivated responding
No full textSelf-control involves the inhibition of dominant response tendencies. Most research on self-control has examined the inhibition of appetitive tendencies, and recent evidence suggests that stimulation to increase right frontal cortical activity helps to inhibit approach-motivated responses. The current experiment paired an approach–avoidance joystick task with transcranial DC stimulation to test the effects of brain stimulation on the inhibition of both approach and avoidance response tendencies. Anodal stimulation over the right/cathodal stimulation over the left dorsolateral prefrontal cortex (compared to the opposite pattern of stimulation or sham stimulation) caused participants to initiate motive-incongruent movements more quickly, thereby suggesting a shared neural mechanism for the self-control of both approach- and avoidance-motivated impulses
The effects of negative emotions on sensory perception: Fear but not anger decreases tactile sensitivity
No full textEmotions and sensory perceptions are closely intertwined. Of the five senses sight has been by far the most extensively studied sense in emotion research. Relatively less is known about how emotions influence the other four senses. Touch is essential for nonverbal communication in both humans and other animals. The current investigation tested competing hypotheses about the effect of fear on tactile perception. One hypothesis based on evolutionary considerations predicts that fear enhances sensory perception, including tactile sensitivity. A competing hypothesis based on research on peripheral psychophysiology predicts that fear should decrease tactile sensitivity. Two experiments that induced negative emotional states and measured two-point discrimination ability found that fear reduces tactile sensitivity relative to anger or a neutral control condition (Studies 1 and 2). These findings did not appear to be driven by participants’ naïve beliefs about the influence of emotions on touch (Study 3). The results represent the first evidence of the causal impact of emotional states on tactile sensitivity, are consistent with prior evidence for the peripheral physiological effects of fear, and offer novel empirical grounds for developing and advancing theories of emotional influences on sensory perception
Thinking about Death Reduces Delay Discounting.
No full textThe current study tested competing predictions regarding the effect of mortality salience on delay discounting. One prediction, based on evolutionary considerations, was that reminders of death increase the value of the present. Another prediction, based in part on construal level theory, was that reminders of death increase the value of the future. One-hundred eighteen participants thought about personal mortality or a control topic and then completed an inter-temporal choice task pitting the chance to gain 50 now for 72.84 in three months in lieu of $50 now. Thus, participants in the mortality salience condition discounted future monetary gains less than other participants, suggesting that thoughts of death may increase the subjective value of the future
Trait approach motivation moderates the aftereffects of self-control
No full textNumerous experiments have found that exercising self-control reduces success on subsequent, seemingly unrelated self-control tasks. Such evidence lends support to a strength model that posits a limited and depletable resource underlying all manner of self-control. Recent theory and evidence suggest that exercising self-control may also increase approach-motivated impulse strength. The two studies reported here tested two implications of this increased approach motivation hypothesis. First, aftereffects of self-control should be evident even in responses that require little or no self-control. Second, participants higher in trait approach motivation should be particularly susceptible to such aftereffects. In support, exercising self-control led to increased optimism (Study 1) and broadened attention (Study 2), but only among individuals higher in trait approach motivation. These findings suggest that approach motivation is an important key to understanding the aftereffects of exercising self-control
After-effects of self-control: The reward responsivity hypothesis
No full textExercising self-control can be phenomenologically aversive. Insofar as individuals strive to maintain a positive emotional state, one consequence of exercising self-control may thus be a temporarily tuning toward or amplification of reward-related impulses (perhaps arising to countermand the aversive feelings that stem from self-control). Reward-relevant after-effects are relatively underappreciated in self-control research. In the current paper, we review theory and research pertaining to the idea that exercising self-control increases reward responsivity. First, we review theoretical models of self-control focusing on the relationship between control systems and reward systems. Second, we review behavioral studies regarding the effects of exercising self-control on subsequent reactivity to food, money, drugs, and positive emotional images. Third, we review findings from functional neuroimaging and electroencephalographic research pertaining to the reward responsivity hypothesis. We then call for additional research to integrate how, when, and under what circumstances self-control exertion influences reward processing. Such an endeavor will help to advance research and theory on self-control by offering a more precise characterization of the dynamic interactions between control systems and reward systems
Histidine and not tyrosine is required for the peroxide-induced formation of haem to protein cross-linked myoglobin
No full textPeroxide- induced oxidative modi. cations of haem proteins such as myoglobin and haemoglobin can lead to the formation of a covalent bond between the haem and globin. These haem to protein cross- linked forms of myoglobin and haemoglobin are cytotoxic and have been identified in pathological conditions in vivo. An understanding of the mechanism of haem to protein cross- link formation could provide important information on the mechanisms of the oxidative processes that lead to pathological complications associated with the formation of these altered myoglobins and haemoglobins. We have re- examined the mechanism of the formation of haem to protein cross- link to test the previously reported hypothesis that the haem forms a covalent bond to the protein via the tyrosine 103 residue ( Catalano, C. E., Choe, Y. S., Ortiz de Montellano, P. R., J. Biol. Chem. 1989, 10534 - 10541). Comparison of native horse myoglobin, recombinant sperm whale myoglobin and Tyr 103 -> Phe sperm whale mutant shows that, contrary to the previously proposed mechanism of haem to protein cross- link formation, the absence of tyrosine 103 has no impact on the formation of haem to protein cross- links. In contrast, we have found that engineered myoglobins that lack the distal histidine residue either cannot generate haem to protein cross- links or show greatly suppressed levels of modified protein. Moreover, addition of a distal histidine to myoglobin from Aplysia limacina, that naturally lacks this histidine, restores the haem protein's capacity to generate haem to protein cross- links. The distal histidine is, therefore, vital for the formation of haem to protein cross- link and we explore this outcome
Electrocortical Effects of Acetaminophen during Emotional Picture Viewing, Cognitive Control, and Negative Feedback
No full textAcetaminophen, the active ingredient in Tylenol, may have psychological effects, such as reducing social and emotional pain. The current study (N = 173) used electroencephalography (EEG) to extend past research on acetaminophen. Healthy undergraduate students (64.7% women, age M = 18.15, SD = 3.33) were randomly assigned to ingest 1,000 mg of acetaminophen or placebo before completing emotional picture viewing (n = 143), a flanker task (n = 69), and a probabilistic learning task (n = 143) while EEG was recorded. (Sample sizes used for the analyses of each task differ from the total N due to data loss.) We observed standard event-related potentials (ERPs), including emotion-modulated late positive potentials during picture viewing and feedback-related negativity during feedback on the probabilistic learning task. We also observed standard error-related and conflict-related ERPs in the flanker task but could not adequately assess acetaminophen\u27s effect on flanker ERPs due to excessive data loss. Acetaminophen did not alter any of the ERPs, in contrast to predictions based on prior research. Exploratory analyses revealed that acetaminophen reduced the relationship between trait behavioral inhibition system sensitivity and emotion-modulated late positive potentials. Together these findings suggest that a standard dose of acetaminophen did not reliably alter neural indicators of emotional or feedback processing. Instead, preliminary findings from our study suggested that a more nuanced relationship may exist between acetaminophen and individual differences in emotional processing, although this latter finding calls for further replication
Casein kinase 2 (CK2) is a bona fide member of the yeast SSU processome and links ribosome assembly to cell growth
No full textRibosome assembly is linked to growth. In both normal growth and development, but also in cancer, cells upregulate ribosome assembly in order to meet the protein synthesis needs of growing cells. However, the mechanism underlying the relationship between growth and ribosome assembly is poorly characterized. The Small Subunit Processome (SSUP) is a 6 MDa complex composed of ribosome assembly proteins, and the U3 snoRNA. It is responsible for the assembly and maturation of the small subunit of the ribosome. The CK2 kinase complex has been implicated in the regulation of cell growth and of all three RNA polymerases required for ribosome assembly. CK2 has been suggested to be part of the UtpC subcomplex of the SSUP by genome-wide affinity-purification/mass spec analyses. However, the membership of CK2 in the SSUP has not been validated by the standard criteria: (i) nucleolar localization, the site of ribosome biogenesis; (ii) association by co-IP with known SSUP proteins; and (iii) a ribosome assembly defect upon depletion of the candidate component. Here, we validate the membership of CK2 in the yeast SSUP. By literature curation, we show that the CK2 components are nucleolar. As well, all four CK2 subunits co-IP the SSUP protein Kre33. Lastly, depletion of both CKa1 and CKa2 catalytic subunits yields a synthetic lethal phenotype along with a statistically significant decrease (p-value [less than] 0.0001) in mature 18S and 25S rRNA. We thus propose that CK2 is a master regulator of ribosome assembly and may link growth to ribosome assembly in both development and in cancer.Includes bibliographical references (pages 49-59).Chapter 2 is co-authored with Cluff by Elise Poole (created the GAL1::3xHA tagged strains in the Kre33-9xMYC background) and J. Michael Charette (study design, data analysis, and editing of manuscript)."In partial fulfillment of the requirements for the degree of Master of Science, Evironmental and Life Sciences.
AAC Brandon Hard Red Spring Wheat
No full textAbstract:
AAC Brandon Hard Red Spring Wheat. Can. J. Plant Sci. ***** 2016.
AAC Brandon hard red spring wheat (Triticum aestivum L.) has grain yield and time to maturity within the range of the check cultivars: Katepwa, Laura, Lillian, Carberry, CDC Kernen. AAC Brandon has an awned spike, a low lodging score indicative of strong straw, and a short plant stature typical of a semidwarf. AAC Brandon expressed resistance to prevalent races of leaf rust, stem rust, and stripe rust, and moderate resistance to fusarium head blight, and loose smut. Compared to the five Canada Western Red Spring check cultivars, AAC Brandon has improved flour yield, and lower flower ash. AAC Brandon is eligible for grades of Canada Western Red Spring.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
Disgust sensitivity predicts defensive responding to mortality salience
No full textDisgust protects the physical self. The present authors suggest that disgust also contributes to the protection of the psychological self by fostering stronger defensive reactions to existential concerns. To test this idea, 3 studies examined the link between disgust sensitivity and defensive responses to mortality salience or "terror management" processes (Greenberg, Solomon, & Pyszczynski, 1997). Each study included an individual difference measure of disgust sensitivity, a manipulation of mortality salience, and a dependent measure of defensive responding. In Study 1, disgust sensitivity predicted increases in worldview defense in the mortality salience condition but not in the control condition. In Study 2, disgust sensitivity predicted increases in optimistic perceptions of the future in the mortality salience condition but not in the control condition. In Study 3, disgust sensitivity predicted reductions in delay discounting for those in the mortality salience condition such that those higher in disgust sensitivity discounted the future less. This pattern did not occur in the control condition. These findings highlight disgust sensitivity as a key to understanding reactions to mortality salience, and they support the view that disgust-related responses protect against both physical (e.g., noxious substances) and psychological threats.</p
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