Effects of ecstasy/polydrug use on memory for associative information

Rationale. Associative learning underpins behaviours that are fundamental to the everyday functioning of the individual. Evidence pointing to learning deficits in recreational drug users merits further examination. Objectives. A word pair learning task was administered to examine associative learning processes in ecstasy/polydrug users. Methods. After assignment to either single or divided attention conditions, 44 ecstasy/polydrug users, and 48 nonusers were presented with 80 word pairs at encoding. Following this, four types of stimuli were presented at the recognition phase; the words as originally paired (old pairs), previously presented words in different pairings (conjunction pairs), old words paired with new words, and pairs of new words (not presented previously). The task was to identify which of the stimuli were intact old pairs. Results. Ecstasy/ploydrug users produced significantly more false positive responses overall compared to nonusers. Increased long-term frequency of ecstasy use was positively associated with the propensity to produce false positive responses. It was also associated with a more liberal signal detection theory (SDT) decision criterion value. Measures of long term and recent cannabis use were also associated with these same word pair learning outcome measures. Conjunction word pairs, irrespective of drug use, generated the highest level of false positive responses and significantly more false positive responses were made in the DA condition compared to the SA condition. Conclusions. Overall, the results suggest that long-term ecstasy exposure may induce a deficit in associative learning and this may be in part a consequence of users adopting a more liberal decision criterion value. Key Words: Ecstasy, Drug Use, Cognition, Memory, Associative Learning, Word Pair

Inappropriate prescribing and adverse drug events in older people

Inappropriate prescribing (IP) in older patients is highly prevalent and is associated with an increased risk of adverse drug events (ADEs), morbidity, mortality and healthcare utilisation. Consequently, IP is a major safety concern and with changing population demographics, it is likely to become even more prevalent in the future. IP can be detected using explicit or implicit prescribing indicators. Theoretically, the routine clinical application of these IP criteria could represent an inexpensive and time efficient method to optimise prescribing practice. However, IP criteria must be sensitive, specific, have good inter-rater reliability and incorporate those medications most commonly associated with ADEs in older people. To be clinically relevant, use of prescribing appropriateness tools must translate into positive patient outcomes, such as reduced rates of ADEs. To accurately measure these outcomes, a reliable method of assessing the relationship between the administration of a drug and an adverse clinical event is required. The Naranjo criteria are the most widely used tool for assessing ADE causality, however, they are often difficult to interpret in the context of older patients. ADE causality criteria that allow for the multiple co-morbidities and prescribed medications in older people are required. Ultimately, the current high prevalence of IP and ADEs is unacceptable. IP screening criteria need to be tested as an intervention to assess their impact on the incidence of ADEs in vulnerable older patients. There is a role for IP screening tools in everyday clinical practice. These should enhance, not replace good clinical judgement, which in turn should be based on sound pharmacogeriatric training

Negative Feedback Regulation following Administration of Chronic Exogenous Corticosterone

Administration of exogenous glucocorticoids is known to suppress the HPA axis and has been reported to occupy brain glucocorticoid receptors, eventually leading to down-regulation. To determine the effects of chronic corticosterone administration on HPA axis function, corticosterone was administered as both 25% and 50% corticosteronekholesterol pellets. Rats were sacrificed 6 days after corticosterone pellet implantation. The 25% corticosterone pellets produced a small increase in morning corticosterone concentrations but no change in evening ACTH or corticosterone secretion. The 50% corticosterone pellets produced constant corticosterone concentrations of 5–6 pg/dl, with no circadian variation in corticosterone, indicating inhibition of evening ACTH and corticosterone secretion. The 25% corticosterone pellets produced no significant decrease in thymus weight or in adrenal weight; 50% corticosterone pellets produced significant decreases in thymus weight and adrenal weight. Neither 25% nor 50% corticosterone pellets produced significant decreases in GR in hippocampus and cortex. The 50% corticosterone pellets treatment resulted in a decrease in anterior pituitary POMC mRNA levels, a decrease in baseline and oCRH stimulated ACTH release from the anterior pituitary, and a near complete inhibition of the AM and PM response to restraint stress. These results suggest that: 1) the HPA axis was able to adjust to the small increase in glucocorticoids produced by the 25% cort pellets with minimal disturbances in function and 2) 50% corticosterone pellets exert a significant inhibitory effect on stress and diurnal ACTH secretion which appears to be exerted at the pituitary as well as possible inhibitory effects on brain.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72571/1/j.1365-2826.1995.tb00665.x.pd

Can Machines Think? Interaction and Perspective Taking with Robots Investigated via fMRI

Krach S, Hegel F, Wrede B, Sagerer G, Binkofski F, Kircher T. Can Machines Think? Interaction and Perspective Taking with Robots Investigated via fMRI. PLoS ONE. 2008;3(7): e2597.Background When our PC goes on strike again we tend to curse it as if it were a human being. Why and under which circumstances do we attribute human-like properties to machines? Although humans increasingly interact directly with machines it remains unclear whether humans implicitly attribute intentions to them and, if so, whether such interactions resemble human-human interactions on a neural level. In social cognitive neuroscience the ability to attribute intentions and desires to others is being referred to as having a Theory of Mind (ToM). With the present study we investigated whether an increase of human-likeness of interaction partners modulates the participants' ToM associated cortical activity. Methodology/Principal Findings By means of functional magnetic resonance imaging (subjects n = 20) we investigated cortical activity modulation during highly interactive human-robot game. Increasing degrees of human-likeness for the game partner were introduced by means of a computer partner, a functional robot, an anthropomorphic robot and a human partner. The classical iterated prisoner's dilemma game was applied as experimental task which allowed for an implicit detection of ToM associated cortical activity. During the experiment participants always played against a random sequence unknowingly to them. Irrespective of the surmised interaction partners' responses participants indicated having experienced more fun and competition in the interaction with increasing human-like features of their partners. Parametric modulation of the functional imaging data revealed a highly significant linear increase of cortical activity in the medial frontal cortex as well as in the right temporo-parietal junction in correspondence with the increase of human-likeness of the interaction partner (computer<functional robot<anthropomorphic robot<human). Conclusions/Significance Both regions correlating with the degree of human-likeness, the medial frontal cortex and the right temporo-parietal junction, have been associated with Theory-of-Mind. The results demonstrate that the tendency to build a model of another's mind linearly increases with its perceived human-likeness. Moreover, the present data provides first evidence of a contribution of higher human cognitive functions such as ToM in direct interactions with artificial robots. Our results shed light on the long-lasting psychological and philosophical debate regarding human-machine interaction and the question of what makes humans being perceived as human

Voice audio methods

This paper explores the potential of voice audio in qualitative research, as data in its own right rather than only as a precursor to transcription. Building on critiques of voice in qualitative research, I argue that audio can enable researchers to work with the more-than-representational excesses of voice. Developing this line of thinking, I draw on Levi Bryant’s machinic ontology to set out a post-humanist conception of voice as arising within ecologies of media machines. As an example of what machinic voice audio can do, I describe an experimental audio work that I produced as part of research on a ruinous landscape. The final section of the paper makes more general observations about the malleability and fallibility of the machinic voice

Uncovering treatment burden as a key concept for stroke care: a systematic review of qualitative research

&lt;b&gt;Background&lt;/b&gt; Patients with chronic disease may experience complicated management plans requiring significant personal investment. This has been termed ‘treatment burden’ and has been associated with unfavourable outcomes. The aim of this systematic review is to examine the qualitative literature on treatment burden in stroke from the patient perspective.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Methods and findings&lt;/b&gt; The search strategy centred on: stroke, treatment burden, patient experience, and qualitative methods. We searched: Scopus, CINAHL, Embase, Medline, and PsycINFO. We tracked references, footnotes, and citations. Restrictions included: English language, date of publication January 2000 until February 2013. Two reviewers independently carried out the following: paper screening, data extraction, and data analysis. Data were analysed using framework synthesis, as informed by Normalization Process Theory. Sixty-nine papers were included. Treatment burden includes: (1) making sense of stroke management and planning care, (2) interacting with others, (3) enacting management strategies, and (4) reflecting on management. Health care is fragmented, with poor communication between patient and health care providers. Patients report inadequate information provision. Inpatient care is unsatisfactory, with a perceived lack of empathy from professionals and a shortage of stimulating activities on the ward. Discharge services are poorly coordinated, and accessing health and social care in the community is difficult. The study has potential limitations because it was restricted to studies published in English only and data from low-income countries were scarce.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Conclusions&lt;/b&gt; Stroke management is extremely demanding for patients, and treatment burden is influenced by micro and macro organisation of health services. Knowledge deficits mean patients are ill equipped to organise their care and develop coping strategies, making adherence less likely. There is a need to transform the approach to care provision so that services are configured to prioritise patient needs rather than those of health care systems

Deficit of social cognition in subjects with surgically treated frontal lobe lesions and in subjects affected by schizophrenia

The ability of humans to predict and explain other people’s behaviour by attributing independent mental states such as desires and beliefs to them, is considered to be due to our ability to construct a “Theory of Mind”. Recently, several neuroimaging studies have implicated the medial frontal lobes as playing a critical role in a dedicated “mentalizing” or “Theory of Mind” network in the human brain. In this study we compare the performance of patients with right and left medial prefrontal lobe lesions in theory of mind and in social cognition tasks, with the performance of people with schizophrenia. We report a similar social cognitive profile between patients with prefrontal lobe lesions and schizophrenic subjects in terms of understanding of false beliefs, in understanding social situations and in using tactical strategies. These findings are relevant for the functional anatomy of “Theory of Mind”

Cooperative Binding

Molecular binding is an interaction between molecules that results in a stable association between those molecules. Cooperative binding occurs if the number of binding sites of a macromolecule that are occupied by a specific type of ligand is a nonlinear function of this ligand’s concentration. This can be due, for instance, to an affinity for the ligand that depends on the amount of ligand bound. Cooperativity can be positive (supralinear) or negative (infralinear). Cooperative binding is most often observed in proteins, but nucleic acids can also exhibit cooperative binding, for instance of transcription factors. Cooperative binding has been shown to be the mechanism underlying a large range of biochemical and physiological processes

Opportunistic screening for skin cancer using a mobile unit in Brazil

Abstract Background Skin cancer is the most common malignancy in the white population worldwide. In Brazil, the National Cancer Institute (INCA) estimates that in 2010 there will be 119,780 and 5,930 new cases of non-melanoma skin cancer and melanoma, respectively. The aim of this study was to evaluate the use of a mobile unit in the diagnosis and treatment of skin cancer in several poor regions of Brazil. Methods The diagnosis of skin cancer was accomplished through active medical screening in the prevention Mobile Unit (MU) of Barretos Cancer Hospital (BCH). The study population consisted of patients examined in the MU between 2004 and 2007, and their suspicious lesions were subjected to histopathological evaluation. Data were collected prospectively from standardized forms and analyzed. Results During the screening, 17,857 consultations were carried out. A total of 2012 (11.2%) cases of skin cancer were diagnosed. The predominant histological type reported was basal cell carcinoma (n = 1,642 or 81.6%), followed by squamous cell carcinoma (n = 303 or 15.1%), Bowen's disease (n = 25 or 1.2%), malignant melanoma (n = 23 or 1.1%), basosquamous cell carcinoma (n = 3 or 0.1%), miscellaneous lesions (12 or 0.6%), and metatypical carcinoma (n = 4 or 0.2%). Only 0.6% of lesions were stage III. There were no stage IV non-melanoma skin lesions, as well as no melanomas stages III and IV, found. Conclusions It was observed that the MU can be a useful tool for early skin cancer diagnosis and treatment. This program probably is important, especially in developing countries with inadequate public health systems and social inequality