48 research outputs found
Political campaigning 2.0: The influence of online news and social networking sites on attitudes and behavior
This study aimed to examine differences in influence between online news (e.g., New York Times) and social networking sites (e.g., Facebook and Twitter) on attitudes in political campaigns. In a web-based experiment, campaign, polls and election between two fictitious candidates were simulated. Participants’ explicit and implicit attitudes as well as voting behavior were assessed using self-report items and the Implicit Association Test (IAT). The results reveal that information emanating from online news had a significant influence on explicit and implicit attitudes while that of social networking sites did not. Overall, negative items had a stronger impact than positive ones, more so in online news compared to social networking sites. Negative information from either type of media was more likely to change participants’ explicit attitudes in a negative direction and as a consequence also change their vote. Practical implications of the findings and limitations of the study are discussed
Vasopressin impairs brain, heart and kidney perfusion: an experimental study in pigs after transient myocardial ischemia
Introduction:
Arginine vasopressin (AVP) is increasingly used to restore mean arterial pressure (MAP) in low-pressure shock states unresponsive to conventional inotropes. This is potentially deleterious since AVP is also known to reduce cardiac output by increasing vascular resistance. The effects of AVP on blood flow to vital organs and cardiac performance in a circulation altered by cardiac ischemia are still not sufficiently clarified. We hypothesised that restoring MAP by low dose, therapeutic level AVP would reduce vital organ blood flow in a setting of experimental acute left ventricular dysfunction.
Methods:
Cardiac output (CO) and arterial blood flow to the brain, heart, kidney and liver were measured in nine pigs using transit-time flow probes. Left ventricular pressure-volume catheter and central arterial and venous catheters were used for haemodynamic recordings and blood sampling. Transient left ventricular ischemia was induced by intermittent left coronary occlusions resulting in a 17% reduction in cardiac output and a drop in MAP from 87 ± 3 to 67 ± 4 mmHg (p < 0.001). A low-dose therapeutic level of AVP (0.005 U/kg/min) was used to restore MAP to pre-ischemic values (93 ± 4 mmHg).
Results:
AVP further impaired systemic perfusion (CO and brain, heart and kidney blood flow reduced by 29, 18, 23 and 34%, respectively) due to a 2.0-, 2.2-, 1.9- and 2.1-fold increase in systemic, brain, heart and kidney specific vascular resistances. The hypoperfusion induced by AVP was associated with an increased systemic oxygen extraction. Oxygen saturation in blood drawn from the great cardiac vein fell from 29 ± 1 to 21 ± 3% (p = 0.01). Finally, these effects were reversed 40 min after AVP was withdrawn.
Conclusion:
Low dose AVP induced a pronounced reduction in vital organ blood flow in pigs after transient cardiac ischemia. This indicates a potentially deleterious effect of AVP in patients with heart failure or cardiogenic shock due to impaired coronary perfusion
Memory for pictures and words - perceptual and semantic factors in the picture superiority effect
Memory for pictures and words - perceptual and semantic factors in the picture superiority effect Georg Stenberg, Växjö University, Sweden Memory for pictures is known to surpass memory for corresponding concrete words, an effect often attributed to the more distinctive perceptual form of pictures. A consequence of this view is that picture superiority would not survive a transformation in which only semantic, not perceptual, features were preserved from study to test, such as studying a picture of a horse and recognising the word "horse". In the present experiments, either pictures or Swedish words were studied. Recognition tests were performed with items in either their original form or translated into English words. (Participants were Swedish students with adequate command of English.) Across three experiments that varied processing depth of the orienting task, the advantage for items studied as pictures was preserved in English-language recognition. Further, a multinomial model with separate parameters for form-based and semantically based recognition was fitted to the data. Results showed (1) that encoding of both semantic and perceptual features was more effective for pictures than for words and (2) that encoding of pictures was less affected by orienting task than encoding of words. The results suggest that pick-up of both semantic and perceptual features is more automatic and efficient for pictures than for words
Perceptual and conceptual contributions to the picture superiority effect
Pictures are typically better remembered than words, but explanations for this fact diverge. Some attribute picture superiority to more distinctive perceptual qualities, others to more efficient conceptual processing. In an effort to separate perceptual and conceptual factors, two groups were presented with mixed lists of pictures and words and were subsequently tested for recognition in either the original or the opposite (picture/word) format. One group, the Format Inclusion group, was instructed to endorse both formats of a studied item; the other - the Format Exclusion group - was instructed to endorse only the original format. Multinomial models were fitted to the response data, with separate parameters for a high-threshold process, recognizing items of high familiarity, and a low-threshold process, rejecting items of low familiarity. Model testing showed that both conceptual and perceptual processing was more efficient for pictures than for words. Especially the low-threshold process showed dramatic picture superiority
Separating semantic and perceptual factors in the picture superiority effect
Memory for pictures is known to surpass memory for corresponding concrete words, an effect often attributed to the more distinctive perceptual form of pictures. A consequence of this view is that picture superiority would not survive a transformation in which only semantic, not perceptual, features were preserved from study to test, such as studying a picture of a horse and recognising the word "horse". In the present experiments, either pictures or Swedish words were studied. Recognition tests were performed with items in either their original form or translated into English words. (Participants were Swedish students with adequate command of English.) Across three experiments that varied processing depth of the orienting task, the advantage for items studied as pictures was preserved in English-language recognition. Further, a multinomial model with separate parameters for form-based and semantically based recognition was fitted to the data. Results showed (1) that encoding of both semantic and perceptual features was more effective for pictures than for words and (2) that encoding of pictures was less affected by orienting task than encoding of words. The results suggest that pick-up of both semantic and perceptual features is more automatic and efficient for pictures than for words
Impulse Control Disorders : The Continuum Hypothesis
The group Parkinson Inside Out is composed of health professionals and academic researchers who have been diagnosed with Parkinson's Disease. In our discussions we try to make use of both our inside perspective as patients, and our outside perspective as professionals. In this paper, we apply the two perspectives to the Impulse Control Disorders. These impulsive behaviour patterns are thought to be relatively uncommon side effects of some of the medication used in dopamine replacement therapy. The phenomenon is usually described as relatively rare