Behavioural correlate of choice confidence in a discrete trial paradigm

How animals make choices in a changing and often uncertain environment is a central theme in the behavioural sciences. There is a substantial literature on how animals make choices in various experimental paradigms but less is known about the way they assess a choice after it has been made in terms of the expected outcome. Here, we used a discrete trial paradigm to characterise how the reward history shaped the behaviour on a trial by trial basis. Rats initiated each trial which consisted of a choice between two drinking spouts that differed in their probability of delivering a sucrose solution. Critically, sucrose was delivered after a delay from the first lick at the spouts--this allowed us to characterise the behavioural profile during the window between the time of choice and its outcome. Rats' behaviour converged to optimum choice, both during the acquisition phase and after the reversal of contingencies. We monitored the post-choice behaviour at a temporal precision of 1 millisecond; lick-response profiles revealed that rats spent more time at the spout with the higher reward probability and exhibited a sparser lick pattern. This was the case when we exclusively examined the unrewarded trials, where the outcome was identical. The differential licking profiles preceded the differential choice ratios and could thus predict the changes in choice behaviour.This research was supported by the Australian Research Council Discovery Project Grant DP0987133 to EA

Photo-responsive polymeric structures based on spiropyran

Spiropyrans are one of the most popular classes of photochromic compounds that change their optical and structural properties in response to external inputs such as light, protons and metal ions, making them ideal molecules for the fabrication of multifunctional stimuli-responsive materials. Nowadays, the emphasis in polymeric materials incorporating spiropyran units, focuses on the effectiveness of their reversible response to external photonic stimuli. Photo-control of a range of key characteristics for flow systems, such as wettability, permeability, photo-modulation of flow by photo-actuation of valves, photonic control of uptake and release of guests using films and coatings, and colorimetric sensing of various species, are highlighted and discussed

Behavioural Correlate of Choice Confidence in a Discrete Trial Paradigm

How animals make choices in a changing and often uncertain environment is a central theme in the behavioural sciences. There is a substantial literature on how animals make choices in various experimental paradigms but less is known about the way they assess a choice after it has been made in terms of the expected outcome. Here, we used a discrete trial paradigm to characterise how the reward history shaped the behaviour on a trial by trial basis. Rats initiated each trial which consisted of a choice between two drinking spouts that differed in their probability of delivering a sucrose solution. Critically, sucrose was delivered after a delay from the first lick at the spouts – this allowed us to characterise the behavioural profile during the window between the time of choice and its outcome. Rats' behaviour converged to optimum choice, both during the acquisition phase and after the reversal of contingencies. We monitored the post-choice behaviour at a temporal precision of 1 millisecond; lick-response profiles revealed that rats spent more time at the spout with the higher reward probability and exhibited a sparser lick pattern. This was the case when we exclusively examined the unrewarded trials, where the outcome was identical. The differential licking profiles preceded the differential choice ratios and could thus predict the changes in choice behaviour

Netrin-1 receptor-deficient mice show age-specific impairment in drug-induced locomotor hyperactivity but still self-administer methamphetamine

Rationale: The mesocorticolimbic dopamine system undergoes significant reorganization of neuronal connectivity and functional refinement during adolescence. Deleted in colorectal cancer (DCC), a receptor for the guidance cue netrin-1, is involved in this reorganization. Previous studies have shown that adult mice with a heterozygous (het) loss-of-function mutation in DCC exhibit impairments in sensitization and conditioned place preference (CPP) to psychostimulants. However, the commonly abused psychostimulant methamphetamine (METH) has not been assessed, and the role of DCC in drug self-administration remains to be established. Objectives: Using dcc het mice and wildtype (WT) littermates, we extended previous findings on dcc haplodeficiency by examining self-administration of METH in adult mice, including cue-induced drug seeking following abstinence. We also examined hyperactivity, sensitization, and CPP to a METH-paired context in adult and adolescent mice. Results: While adult dcc het mice expressed largely similar METH self-administration and cue-induced drug seeking as WT littermates, they failed to modulate responding according to dose of METH. Compared to WT, both adult and adolescent dcc het mice expressed impaired locomotor hyperactivity to acute METH but nevertheless showed comparable behavioral sensitization. Conditioned hyperactivity increased with age in WT but not in dcc het mice. Conclusions: Impaired METH-induced hyperactivity and dose-related responding in adult dcc het mice suggest that reduced DCC alters METH-related behaviors. Adolescence is identified as a vulnerable period during which impairment in hyperactivity due to reduced DCC can be overcome with repeated METH injections. Nevertheless, DCC appears to have a somewhat limited role in METH-consumption and seeking following abstinence

Comparison of the choice and time indices.

<p>A. The choice index (I_c – green lines) and time index (I_t – blue lines) in the first two sessions after reversal. The data points represent 50 successive and non-overlapping trials in a session. Data are averaged across all four rats. The time index passes 0 before the choice index, indicating that time spent at the high reward spout exceeds time spent at the low reward spout, long before the high reward spout is chosen more frequently.</p

The distribution of times spent at spouts on unrewarded trials.

<p>A. Time spent at spout is defined as the time duration between the beginning of the first lick to the end of the last lick on each trial. Black vertical lines represent median times spent at high reward spout. Red vertical lines represent median times spent at low reward spout. Distributions are normalised for total number of trials. Top panel: Data from all sessions. Middle panel: Data from the first acquisition session only. Bottom Panel: Data from the first reversal session only. B. Box plot of data from all sessions, plotted per rat. The whiskers indicate the extent of the data (the minimum and maximum after excluding outliers), box and middle line indicate lower and upper quartiles and median, respectively. C. Quantile-quantile plots (Q-Q plots) per individual rat. Corresponding quantiles for high and low rewards spouts are calculated at 5% steps and plotted against one another. All points lie above the diagonal line, indicating that rats wait longer at the high than the low reward spout. However, there is no systematic deviation from linearity, suggesting no other systematic difference between the distribution of waiting times.</p

Deprescribing practices, habits and attitudes of geriatricians and geriatricians-in-training across Europe: a large web-based survey

Purpose To provide an overview of the current deprescribing attitudes, practices, and approaches of geriatricians and geriatricians-in-training across Europe. Methods An online survey was disseminated among European geriatricians and geriatricians-in-training. The survey comprised Likert scale and multiple-choice questions on deprescribing approaches and practices, deprescribing education and knowledge, and facilitators/barriers of deprescribing. Responses to the survey questions and participant characteristics were quantified and differences evaluated between geriatricians and geriatricians-in-training and between European regions. Results The 964 respondents (median age 42 years old; 64% female; 21% geriatricians-in-training) were generally willing to deprescribe (98%) and felt confident about deprescribing (85%). Despite differences across European regions, the most commonly reported reasons for deprescribing were functional impairment and occurrence of adverse drug reactions. The most important barriers for deprescribing were patients' unwillingness, fear of negative consequences, lack of time, and poor communication between multiple prescribers. Perceived risk of adverse drug reactions was highest for psychotropic drugs, nonsteroidal anti-inflammatory drugs, cardiovascular drugs, and opioid analgesics. Only one in four respondents (23% of geriatricians and 37% of geriatricians-in-training) think education in medical school had sufficiently prepared them for deprescribing in clinical practice. They reported that their future deprescribing activities would probably increase with improved information sharing between various prescribers, deprescribing recommendations in guidelines, and increased education and training. Approximately 90% think that a paradigm shift is required for prescribers and patients, increasing focus on the possible benefits of deprescribing (potentially) inappropriate medications. Conclusions Based on the outcomes of this survey, we recommend investing in improved inter-professional communication, better education and evidence-based recommendations to improve future patient-centered deprescribing practices

Deprescribing practices, habits and attitudes of geriatricians and geriatricians-in-training across Europe : a large web-based survey

Abstract: Purpose To provide an overview of the current deprescribing attitudes, practices, and approaches of geriatricians and geriatricians-in-training across Europe. Methods: An online survey was disseminated among European geriatricians and geriatricians-in-training. The survey comprised Likert scale and multiple-choice questions on deprescribing approaches and practices, deprescribing education and knowledge, and facilitators/barriers of deprescribing. Responses to the survey questions and participant characteristics were quantified and differences evaluated between geriatricians and geriatricians-in-training and between European regions. Results: The 964 respondents (median age 42 years old; 64% female; 21% geriatricians-in-training) were generally willing to deprescribe (98%) and felt confident about deprescribing (85%). Despite differences across European regions, the most commonly reported reasons for deprescribing were functional impairment and occurrence of adverse drug reactions. The most important barriers for deprescribing were patients’ unwillingness, fear of negative consequences, lack of time, and poor communication between multiple prescribers. Perceived risk of adverse drug reactions was highest for psychotropic drugs, nonsteroidal anti-inflammatory drugs, cardiovascular drugs, and opioid analgesics. Only one in four respondents (23% of geriatricians and 37% of geriatricians-in-training) think education in medical school had sufficiently prepared them for deprescribing in clinical practice. They reported that their future deprescribing activities would probably increase with improved information sharing between various prescribers, deprescribing recommendations in guidelines, and increased education and training. Approximately 90% think that a paradigm shift is required for prescribers and patients, increasing focus on the possible benefits of deprescribing (potentially) inappropriate medications. Conclusions: Based on the outcomes of this survey, we recommend investing in improved inter-professional communication, better education and evidence-based recommendations to improve future patient-centered deprescribing practices