Manipulating Memory Associations Changes Decision-making Preferences in a Preconditioning Task

Memories of past experiences can guide our decisions. Thus, if memories are undermined or distorted, decision making should be affected. Nevertheless, little empirical research has been done to examine the role of memory in reinforcement decision-making . We hypothesized that if memories guide choices in a conditioning decision-making task, then manipulating these memories would result in a change of decision preferences to gain reward. We manipulated participants’ memories by providing false feedback that their memory associations were wrong before they made decisions that could lead them to win money . Participants’ memory ratings decreased significantly after receiving false feedback. More importantly, we found that false feedback led participants’ decision bias to disappear after their memory associations were undermined . Our results suggest that reinforcement decision-making can be altered by fasle feedback on memories . The results are discussed using memory mechanisms such as spreading activation theories

Estimate of halo ellipticity as a function of radius with flexions

The cold dark matter theory predicts triaxial dark matter haloes. The radial distribution of halo ellipticity depends on baryonic processes and the nature of dark matter particles (collisionless or collisional). Here we show that we can use lensing flexion ratios to measure the halo ellipticity as a function of radius. We introduce a weight function and study the relationship between the first and second order statistics of flexion ratios, both of which can be used to reduce the bias in the estimate of ellipticity. we perform numerical tests for our method, and demonstrate that it can reduce the bias and determine the halo ellipticity as a function of radius. We also point out that the minimum mean flexion ratio can be used to trace the centres of galaxy clusters.Comment: 9 pages,9 figures, MNRAS accepte

The nature and consequences of false memories for visual stimuli

Different theoretical views exist regarding whether false memories contain perceptual information or are merely conceptual in nature. To address this question, we conducted three experiments to examine whether false memories for pictures had a priming effect on a perceptual closure task. In Experiment 1, participants were presented with pictorial versions of Deese/Roediger - McDermott (DRM) lists and received a recognition task. Finally, in the perceptual closure task (PCT), participants were shown degraded pictures (studied pictures, critical pictures , unrelated pictures) that became clearer over time and had to identify the object depicted as quickly as possible. The results showed that false memories for pictures did not exhibit a priming effect in the PCT. Specifically, picture identifications based on false memories for visual stimuli were significantly slower than those based on true memories and the former did not differ from that of unrelated items . In Experiments 2 and 3, we manipulated the modality (ve rbal vs. pictorial) of the study phase and the PCT phase . In both experiments , false memories for pictures primed pictures significantly slower than true memories in the pictorial PCT, but false memories for pictures primed words faster than true memories in the verbal PCT. Our results suggest that false memories for pictures are unlikely to contain perceptual information but rather that they are conceptual in nature

The nature and consequences of false memories for visual stimuli

Different theoretical views exist regarding whether false memories contain perceptual information or are merely conceptual in nature. To address this question, we conducted three experiments to examine whether false memories for pictures had a priming effect on a perceptual closure task. In Experiment 1, participants were presented with pictorial versions of Deese/Roediger - McDermott (DRM) lists and received a recognition task. Finally, in the perceptual closure task (PCT), participants were shown degraded pictures (studied pictures, critical pictures , unrelated pictures) that became clearer over time and had to identify the object depicted as quickly as possible. The results showed that false memories for pictures did not exhibit a priming effect in the PCT. Specifically, picture identifications based on false memories for visual stimuli were significantly slower than those based on true memories and the former did not differ from that of unrelated items . In Experiments 2 and 3, we manipulated the modality (ve rbal vs. pictorial) of the study phase and the PCT phase . In both experiments , false memories for pictures primed pictures significantly slower than true memories in the pictorial PCT, but false memories for pictures primed words faster than true memories in the verbal PCT. Our results suggest that false memories for pictures are unlikely to contain perceptual information but rather that they are conceptual in nature

The Consequences of Implicit and Explicit Beliefs on Food Preferences

Memories can have consequences on people's eating behavior. In the current experiment, we examined the effect of belief versus recollection on food preferences and then investigated whether explicit belief (i.e., self- reported) or implicit belief (i.e., measured by an autobiographical implicit association test; aIAT) had a similar effect on food preferences. Participants (N = 163) were falsely told that they got sick after eating egg salad in their childhood and then received guided imagery to induce false beliefs/recollections concerning the food-aversive event. Half of the participants with false memories were debriefed and told that the event was false to reduce their belief in the event. Belief, not recollection regarding the food-aversive event, impacted participants' food preferences. Furthermore, we found that explicit, but not implicit, belief predicted participants' food preferences. The current results suggest that explicit judgments of belief in a memory may explain the consequences resulting from memories

Phase I study of high-dose epirubicin and vinorelbine in previously untreated non-small-cell lung cancer stage IIIB-IV.

The aim of the study was to determine the maximum tolerated dose (MTD) for the combination of high-dose epirubicin and vinorelbine in chemotherapy-naive patients with inoperable non-small-cell lung cancer (NSCLC). Twenty-one patients with stage IIIB and IV NSCLC were treated in a single-centre study with escalating doses of epirubicin and vinorelbine given on an outpatient basis. The first dose level comprised epirubicin 100 mg m-2 on day 1 and vinorelbine 20 mg m-2 (days 1 and 8) given intravenously every 3 weeks. Escalating doses for epirubicin and vinorelbine were respectively 120 (day 1) and 20 (days 1 and 8), 120 (day 1) and 25 (days 1 and 8) and 135 (day 1) and 25 (days 1 and 8) mg m-2. Inclusion criteria were age < or = 75 years, ECOG performance score < or = 2 and normal renal, hepatic and bone marrow functions. Dose-limiting toxicities were thrombocytopenia grade II and neutropenia grade III on day 8, febrile neutropenia, and neutropenia lasting > 7 days. No dose-limiting toxicity (DLT) was observed at the first dose level; at the 135/25 mg m-2 dose level three out of six patients had a DLT which was considered as unacceptable. The only non-haematological toxicity reaching grade III was nausea/vomiting. One patient showed cardiac toxicity. No neurotoxicity and no treatment-related deaths were seen. The maximum tolerated dose of epirubicin and vinorelbine is 135 mg m-2 (day 1) and 25 mg m-2 (days 1 and 8) respectively, causing mainly haematological toxicity. The recommended dose of epirubicin and vinorelbine for phase II studies is found to be 120 mg m-2 and 20 mg m-2 respectively

Metabolism and growth inhibition of four retinoids in head and neck squamous normal and malignant cells

Isotretinoin (13- cis -retinoic acid, 13cRA) has proven to be active in chemoprevention of head and neck squamous cell carcinoma (HNSCC). Moreover, both all-trans-retinoic acid (ATRA) and 13cRA induce objective responses in oral premalignant lesions. After binding of retinoids to retinoic acid receptors (RARs and RXRs) dimers are formed that are able to regulate the expression of genes involved in growth and differentiation. We compared the metabolism and level of growth inhibition of 13cRA with that of ATRA, 9cRA and retinol in four HNSCC cell lines and normal oral keratinocyte cultures (OKC). These retinoid compounds are known to bind with different affinities to the retinoic acid receptors. We observed that all retinoids were similar with respect to their capacity to induce growth inhibition. One HNSCC line could be ranked as sensitive, one as moderately sensitive and the remaining two were totally insensitive; OKC were moderately sensitive. The rate at which the cells were able to catabolize the retinoid was similar for all compounds. Retinoid metabolism in HNSCC cells resulted in a profile of metabolites that was unique for each retinoid. These metabolic profiles were different in OKC. Our findings indicate that differences in retinoid receptor selectivity of these retinoids do not influence the level of growth inhibition and rate of metabolism. © 2001 Cancer Research Campaign http://www.bjcancer.co

Gebruikservaringen met het Biofix-systeem op het Proefstation

In dit artikel worden de gebruikservaringen met het Biofix-systeem gedurende de aanloopperiode beschreven. Het aantal wisselingen bij de voertrog en/of agressieve interacties tussen zeugen tijdens het voeren is te hoog. Controle tijdens het voeren is nodig, vooral bij de nieuw ingezette groepe

Eddy covariance methane measurements at a Ponderosa pine plantation in California

Long term methane flux measurements have been mostly performed with plant or soil enclosure techniques on specific components of an ecosystem. New fast response methane analyzers make it possible to use the eddy covariance (EC) technique instead. The EC technique is advantageous because it allows continuous flux measurements integrating over a larger and more representative area including the complete ecosystem, and allows fluxes to be observed as environmental conditions change naturally without disturbance. We deployed the closed-path Fast Methane analyzer (FMA) from Los Gatos Research Ltd and demonstrate its performance for EC measurements at a Ponderosa pine plantation at the Blodgett Forest site in central California. The fluctuations of the CH&lt;sub&gt;4&lt;/sub&gt; concentration measured at 10 Hz appear to be small and their standard deviation is comparable to the magnitude of the signal noise (&amp;plusmn;5 ppbv). Consequently, the power spectra typically have a white noise signature at the high frequency end (a slope of +1). Nevertheless, in the frequency range important for turbulent exchange, the cospectra of CH&lt;sub&gt;4&lt;/sub&gt; compare very well with all other scalar cospectra confirming the quality of the FMA measurements are good for the EC technique. We furthermore evaluate the complications of combined open and closed-path measurements when applying the Webb-Pearman-Leuning (WPL) corrections (Webb et al., 1980) and the consequences of a phase lag between the water vapor and methane signal inside the closed path system. The results of diurnal variations of CH&lt;sub&gt;4&lt;/sub&gt; concentrations and fluxes are summarized and compared to the monthly results of process-based model calculations