604 research outputs found
EXPRESS: Attention biases in the inverse base-rate effect persist into new learning
The inverse base-rate effect is a tendency to predict the rarer of two outcomes when presented with cues that make conflicting predictions. Attention-based accounts of the effect appeal to prioritised attention to predictors of rare outcomes. Changes in the processing of these cues is predicted to increase the rate at which they are learned about in the future (i.e. their associability). Our previous work has shown that the development of the inverse base-rate effect is accompanied by greater overt attention to the rare predictor while participants made predictions, and during feedback, and these biases changed in different ways depending on the stage of training and global base-rate differences. It is unknown whether these gaze patterns reflect the manner in which cues are prioritised for learning or are merely a consequence of learning what the cues predict. This study tested whether the associability of common and rare predictors differed, and if so, how this difference changed as a function of training length and the presence of base-rate differences in the outcomes. Experiment 1 tested cue associability using a second learning task presented after either short or long training. The results suggest an associability advantage for rare predictors that weakens with extended training, and is not strongly affected by the presence of global base-rate differences. However, Experiment 2 showed a clear effect of global base-rate differences on choice after very brief training, indicating that attention biases as measured by associability change are not sufficient to produce the inverse base-rate effect
Hearing hooves, thinking zebras: A review of the inverse base-rate effect
People often fail to use base-rate information appropriately in decision-making. This is evident in the inverse base-rate effect, a phenomenon in which people tend to predict a rare outcome for a new and ambiguous combination of cues. While the effect was first reported in 1988, it has recently seen a renewed interest from researchers concerned with learning, attention and decision-making. However, some researchers have raised concerns that the effect arises in specific circumstances and is unlikely to provide insight into general learning and decision-making processes. In this review, we critically evaluate the evidence for and against the main explanations that have been proposed to explain the effect, and identify where this evidence is currently weak. We argue that concerns about the effect are not well supported by the data. Instead, the evidence supports the conclusion that the effect is a result of general mechanisms that provides a useful opportunity to understand the processes involved in learning and decision making. We discuss gaps in our knowledge and some promising avenues for future research, including the relevance of the effect to models of attentional change in learning, an area where the phenomenon promises to contribute new insights
Neural regions associated with gain-loss frequency and average reward in older and younger adults
Research on the biological basis of reinforcement-learning has focused on how brain regions track expected value based on average reward. However, recent work suggests that humans are more attuned to reward frequency. Furthermore, older adults are less likely to use expected values to guide choice than younger adults. This raises the question of whether brain regions assumed to be sensitive to average reward, like the medial and lateral PFC, also track reward frequency, and whether there are age-based differences. Older (60-81 years) and younger (18-30 years) adults performed the Soochow Gambling task, which separates reward frequency from average reward, while undergoing fMRI. Overall, participants preferred options that provided negative net payoffs, but frequent gains. Older adults improved less over time, were more reactive to recent negative outcomes, and showed greater frequency-related activation in several regions, including DLPFC. We also found broader recruitment of prefrontal and parietal regions associated with frequency value and reward prediction errors in older adults, which may indicate compensation. The results suggest greater reliance on average reward for younger adults than older adults
Bimbingan Saudara Baru Melalui Model Pendidikan Berasrama di Asrama Darul Hidayah, Kuala Lumpur
Kajian ini menfokuskan penerapan model pendidikan berasrama kepada saudara baru. Ia merupakan kaedah bimbingan saudara baru yang digunakan oleh pihak Jabatan Agama Islam Wilayah (JAWI). Memandangkan saudara baru adalah golongan yang belum kukuh kefahaman dan pegangan mereka terhadap agama Islam. Maka, model bimbingan saudara baru berkonsepkan asrama diwujudkan bagi membentuk persekitaran yang bercorak Islami. Kajian ini bertujuan untuk menjelaskan konsep model pendidikan berasrama, mengetahui pelaksanaan model pendidikan berasrama di Asrama Darul Hidayah dan mengenal pasti nilai-nilai Islam yang wujud dalam model pendidikan berasrama. Kajian ini merupakan kajian kualitatif (kualitatif research). Pengumpulan data dilakukan dengan menggunakan observasi, wawancara dan dokumentasi. Model analisis data yang digunakan dalam kajian ini adalah deskriptif analisis. Dengan langkah-langkah pengumpulan data, reduksi data, penyajian data dan penarikan kesimpulan. Kajian menunjukkan bahawa bimbingan yang diterapkan melalui model pendidikan berasrama mempunyai elemen-elemen pembelajaran, kelaziman, pengembangan diri, keteladanan, menjalin komunikasi dengan para mubaligh (pengajar), penerima nasihat dan perhatian. Elemen-elemen tersebut menyumbang kepada penambahbaikan dalam meningkatkan kualiti saudara baru dalam aspek ilmu pengetahuan Islam, pengamalannya sekaligus mampu berinteraksi bersama masyarakat dengan baik.Kajian ini menfokuskan penerapan model pendidikan berasrama kepada saudara baru. Ia merupakan kaedah bimbingan saudara baru yang digunakan oleh pihak Jabatan Agama Islam Wilayah (JAWI). Memandangkan saudara baru adalah golongan yang belum kukuh kefahaman dan pegangan mereka terhadap agama Islam. Maka, model bimbingan saudara baru berkonsepkan asrama diwujudkan bagi membentuk persekitaran yang bercorak Islami. Kajian ini bertujuan untuk menjelaskan konsep model pendidikan berasrama, mengetahui pelaksanaan model pendidikan berasrama di Asrama Darul Hidayah dan mengenal pasti nilai-nilai Islam yang wujud dalam model pendidikan berasrama. Kajian ini merupakan kajian kualitatif (kualitatif research). Pengumpulan data dilakukan dengan menggunakan observasi, wawancara dan dokumentasi. Model analisis data yang digunakan dalam kajian ini adalah deskriptif analisis. Dengan langkah-langkah pengumpulan data, reduksi data, penyajian data dan penarikan kesimpulan. Kajian menunjukkan bahawa bimbingan yang diterapkan melalui model pendidikan berasrama mempunyai elemen-elemen pembelajaran, kelaziman, pengembangan diri, keteladanan, menjalin komunikasi dengan para mubaligh (pengajar), penerima nasihat dan perhatian. Elemen-elemen tersebut menyumbang kepada penambahbaikan dalam meningkatkan kualiti saudara baru dalam aspek ilmu pengetahuan Islam, pengamalannya sekaligus mampu berinteraksi bersama masyarakat dengan baik
Peranan Pegawai Penguatkuasa Agama (PPA) Dalam Melaksanakan Hisbah di Negeri Selangor
Hisbah merupakan salah satu elemen yang wujud dalam amalan pengurusan Islam bagi memenuhi tanggungjawab menyeru kepada kebajikan dan mencegah kemungkaran (amar maaruf nahi munkar). Ia mempunyai skop yang luas merangkumi aspek ekonomi, sosial dan politik. Dalam pelaksanaan hisbah di Selangor, tumpuan banyak diberikan kepada aspek yang pencegahan maksiat menerusi penubuhan skuad yang dinamakan dengan Pegawai Penguatkuasa Agama (PPA). Oleh itu kajian ini bertujuan untuk meneliti peranan sebenar PPA dalam melaksanakan hisbah Pengurusan Hal Ehwal Islam (PHEI) di Negeri Selangor khususnya dari sudut bidangkuasa. Ini merupakan kajian kualitatif yang menggunakan kaedah analisis dokumen dalam pengumpulan data kajian. Hasil kajian mendapati bahawa konsep hisbah yang dilaksanakan tertumpu kepada aspek kesalahan berhubung dengan kesusilaan (pencegahan maksiat), akidah, kesucian agama Islam dan institusinya serta kesalahan pelbagai. PPA juga turut memainkan peranan yang cukup besar dan penting dalam usaha menjalankan tugas amar maaruf nahi mungkar di Negeri Selangor demi menjaga kemaslahatan agama dan masyarakat Islam. Jelasnya bidangkuasa PPA dalam menjalankan tugas hisbah tersebut adalah tertakluk kepada apa yang telah termaktub di dalam enakmen-enakmen yang berhubung dengan undang-undang pentadbiran agama Islam Negeri Selangor Darul Ehsan. Kajian ini juga wajar diteruskan dan diperkembangkan lagi pada masa akan datang untuk kepentingan bersama bagi mentransformasikan Pengurusan Hal Ehwal Islam (PHEI) di Malaysia ke arah yang lebih baik khususnya dalam usaha pelaksanaan hisbah.Hisbah merupakan salah satu elemen yang wujud dalam amalan pengurusan Islam bagi memenuhi tanggungjawab menyeru kepada kebajikan dan mencegah kemungkaran (amar maaruf nahi munkar). Ia mempunyai skop yang luas merangkumi aspek ekonomi, sosial dan politik. Dalam pelaksanaan hisbah di Selangor, tumpuan banyak diberikan kepada aspek yang pencegahan maksiat menerusi penubuhan skuad yang dinamakan dengan Pegawai Penguatkuasa Agama (PPA). Oleh itu kajian ini bertujuan untuk meneliti peranan sebenar PPA dalam melaksanakan hisbah Pengurusan Hal Ehwal Islam (PHEI) di Negeri Selangor khususnya dari sudut bidangkuasa. Ini merupakan kajian kualitatif yang menggunakan kaedah analisis dokumen dalam pengumpulan data kajian. Hasil kajian mendapati bahawa konsep hisbah yang dilaksanakan tertumpu kepada aspek kesalahan berhubung dengan kesusilaan (pencegahan maksiat), akidah, kesucian agama Islam dan institusinya serta kesalahan pelbagai. PPA juga turut memainkan peranan yang cukup besar dan penting dalam usaha menjalankan tugas amar maaruf nahi mungkar di Negeri Selangor demi menjaga kemaslahatan agama dan masyarakat Islam. Jelasnya bidangkuasa PPA dalam menjalankan tugas hisbah tersebut adalah tertakluk kepada apa yang telah termaktub di dalam enakmen-enakmen yang berhubung dengan undang-undang pentadbiran agama Islam Negeri Selangor Darul Ehsan. Kajian ini juga wajar diteruskan dan diperkembangkan lagi pada masa akan datang untuk kepentingan bersama bagi mentransformasikan Pengurusan Hal Ehwal Islam (PHEI) di Malaysia ke arah yang lebih baik khususnya dalam usaha pelaksanaan hisbah
Surface thermodynamic homeostasis of salivary conditioning films through polarâapolar layering
Salivary conditioning films (SCFs) form on all surfaces exposed to the oral cavity and control diverse oral surface phenomena. Oral chemotherapeutics and dietary components present perturbations to SCFs. Here we determine the surface energetics of SCFs through contact angle measurements with various liquids on SCFs following perturbations with a variety of chemotherapeutics as well as after renewed SCF formation. Sixteen-hour SCFs on polished enamel surfaces were treated with a variety of chemotherapeutics, including toothpastes and mouthrinses. After treatment with chemotherapeutics, a SCF was applied again for 3Â h. Contact angles with four different liquids on untreated and treated SCF-coated enamel surfaces were measured and surface free energies were calculated. Perturbations either caused the SCF to become more polar or more apolar, but in all cases, renewed SCF formation compensated these changes. Thus, a polar SCF attracts different salivary proteins or adsorbs proteins in a different conformation to create a more apolar SCF surface after renewed SCF formation and vice versa for apolar SCFs. This polarâapolar layering in SCF formation presents a powerful mechanism in the oral cavity to maintain surface thermodynamic homeostasisâdefining oral surface properties within a narrow, biological range and influencing chemotherapeutic strategies. Surface chemical changes brought about by dietary or chemotherapeutic perturbations to SCFs make it more polar or apolar, but new SCFs are rapidly formed compensating for changes in surface energetics
Effective Rheology of Bubbles Moving in a Capillary Tube
We calculate the average volumetric flux versus pressure drop of bubbles
moving in a single capillary tube with varying diameter, finding a square-root
relation from mapping the flow equations onto that of a driven overdamped
pendulum. The calculation is based on a derivation of the equation of motion of
a bubble train from considering the capillary forces and the entropy production
associated with the viscous flow. We also calculate the configurational
probability of the positions of the bubbles.Comment: 4 pages, 1 figur
Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at â s = 8 TeV with the ATLAS detector
Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fbâ1 of â s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
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