Sense of agency, associative learning, and schizotypy

Despite the fact that the role of learning is recognised in empirical and theoretical work on sense of agency (SoA), the nature of this learning has, rather surprisingly, received little attention. In the present study we consider the contribution of associative mechanisms to SoA. SoA can be measured quantitatively as a temporal linkage between voluntary actions and their external effects. Using an outcome blocking procedure, it was shown that training action-outcome associations under conditions of increased surprise augmented this temporal linkage. Moreover, these effects of surprise were correlated with schizotypy scores, suggesting that individual differences in higher level experiences are related to associative learning and to its impact on SoA. These results are discussed in terms of models of SoA, and our understanding of disrupted SoA in certain disorders

Attribution of intentional causation influences the perception of observed movements: behavioral evidence and neural correlates

Recent research on human agency suggests that intentional causation is associated with a subjective compression in the temporal interval between actions and their effects. That is, intentional movements and their causal effects are perceived as closer together in time than equivalent unintentional movements and their causal effects. This so-called intentional binding effect is consistently found for one's own self-generated actions. It has also been suggested that intentional binding occurs when observing intentional movements of others. However, this evidence is undermined by limitations of the paradigm used. In the current study we aimed to overcome these limitations using a more rigorous design in combination with functional Magnetic Resonance Imaging (fMRI) to explore the neural underpinnings of intentional binding of observed movements. In particular, we aimed to identify brain areas sensitive to the interaction between intentionality and causality attributed to the observed action. Our behavioral results confirmed the occurrence of intentional binding for observed movements using this more rigorous paradigm. Our fMRI results highlighted a collection of brain regions whose activity was sensitive to the interaction between intentionality and causation. Intriguingly, these brain regions have previously been implicated in the sense of agency over one's own movements. We discuss the implications of these results for intentional binding specifically, and the sense of agency more generally

Time, action and psychosis: using subjective time to investigate the effects of ketamine on sense of agency

Sense of agency refers to the experience of initiating and controlling actions in order to influence events in the outside world. A disturbed sense of agency is found in certain psychiatric and neurological disorders, most notably schizophrenia. Sense of agency is associated with a subjective compression of time: actions and their outcomes are perceived as bound together in time. This is known as ‘intentional binding’ and, in healthy adults, depends partly on advance prediction of action outcomes. Notably, this predictive contribution is disrupted in patients with schizophrenia. In the present study we aimed to characterise the psychotomimetic effect of ketamine, a drug model for psychosis, on the predictive contribution to intentional binding. It was shown that ketamine produced a disruption that closely resembled previous data from patients in the early, prodromal, stage of schizophrenic illness. These results are discussed in terms of established models of delusion formation in schizophrenia. The link between time and agency, more generally, is also considered

The efficacy of sanctuary areas for the management of fish stocks and biodiversity in WA waters

Debate concerning the relative benefits of marine protected areas (MPAs) for the management of marine resources can often reflect unrecognized differences in the scope, scale and definitions of the objectives being sought by various Government or community bodies. There can also be different opinions on the level of protection required for an area to be considered an ‘MPA’ and functional definitions for both the biological diversity and ecosystems within these areas are often lacking. This paper seeks to outline the relative efficiency and effectiveness of MPAs, especially no-take sanctuary areas, compared to other strategies currently employed to help achieve the main objective of the Western Australian (WA) Fish Resources Management Act (FRMA) 1994, which is “to conserve fish* and protect their environment”. This objective covers the conservation of most of the marine resources of the WA coast, including fish stock management; habitat protection and biodiversity generally out to the 200 m depth contour

Digital demodulator-correlator

An apparatus for demodulation and correlation of a code modulated 10 MHz signal is presented. The apparatus is comprised of a sample and hold analog-to-digital converter synchronized by a frequency coherent 40 MHz pulse to obtain four evenly spaced samples of each of the signal. Each sample is added or subtracted to or from one of four accumulators to or from the separate sums. The correlation functions are then computed. As a further feature of the invention, multipliers are each multiplied by a squarewave chopper signal having a period that is long relative to the period of the received signal to foreclose contamination of the received signal by leakage from either of the other two terms of the multipliers

THE DETERMINANTS OF FOOD STAMP PROGRAM PARTICIPATION

Food Security and Poverty,

FARM COMMODITY PAYMENT LIMITS: WHAT IMPACT WILL THEY HAVE ON THE ECONOMIC VIABILITY OF SOUTHEASTERN AGRICULTURE?

Agricultural and Food Policy,

Experience in Production of 68Ga-DOTA-NOC for Clinical Use Under an Expanded Access IND

[68Ga]Ga-DOTA-NOC was produced under an Expanded Access IND for 174 clinical PET/CT studies to evaluate patients with neuroendocrine tumors. Production employed either the TiO2-based Eckert & Ziegler (EZAG) 68Ge/68Ga-generator (with fractionated elution), or the SiO2-based ITG 68Ge/68Ga-generator. In both cases, [68Ga]Ga-DOTA-NOC was reliably produced, without pre-synthesis purification of the68Ga generator eluate, using readily-implemented manual synthesis procedures. [68Ga]Ga-DOTA-NOC radiochemical purity averaged 99.2±0.4%. Administered 68Ga dose averaged 181±22 MBq, and administered peptide mass averaged 43.2±5.2 µg (n=47) and 23.9±5.7 µg (n=127), respectively, using the EZAG and ITG generators. At dose expiration, 68Ge breakthrough in the final product averaged 2.7×10−7% and 5.4×10−5% using the EZAG and ITG generators, respectively

Effect of stress and temperature on the optical properties of silicon nitride membranes at 1550 nm

Future gravitational-wave detectors operated at cryogenic temperatures are expected to be limited by thermal noise of the highly reflective mirror coatings. Silicon nitride is an interesting material for such coatings as it shows very low mechanical loss, a property related to low thermal noise, which is known to further decrease under stress. Low optical absorption is also required to maintain the low mirror temperature. Here, we investigate the effect of stress on the optical properties at 1,550 nm of silicon nitride membranes attached to a silicon frame. Our approach includes the measurement of the thermal expansion coefficient and the thermal conductivity of the membranes. The membrane and frame temperatures are varied, and translated into a change in stress using finite element modeling. The resulting product of the optical absorption and thermo-optic coefficient (dn/dT) is measured using photothermal common-path interferometry

Performance of a 62Zn/62Cu microgenerator in kit-based synthesis and delivery of [62Cu]Cu–ETS for PET perfusion imaging

The performance of a commercially produced 62Zn/62Cu microgenerator system, and an associated kit-based radiopharmaceutical synthesis method, was evaluated for clinical site production of [62Cu]Cu-ETS (ethylglyoxal bis(thiosemicarbazonato)copper(II)), an investigational agent for PET perfusion imaging. Using 37 generators, containing 1.84 ± 0.23 GBq 62Zn at 9:00 AM on the day of clinical use, a total of 45 patient doses of [62Cu]Cu-ETS (672 ± 172 MBq) were delivered without difficulty. 62Cu elution yields were high (approximately 90%), accompanied by extremely low 62Zn breakthrough (<0.001%). Radiopharmaceutical preparation, from the start-of-elution to time-of-injection, consumed less than five minutes. The 62Zn/62Cu microgenerator was a dependable source of short-lived positron-emitting 62Cu, and the kit-based synthesis proved to be rapid, robust, and highly reliable for “on-demand” delivery of [62Cu]Cu-ETS for PET perfusion imaging