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Rationale: When people with drug addiction encounter cues associated with drug use, this can trigger cravings and relapse. These cues can include conditioned stimuli (CSs) signaling drug delivery and discriminative stimuli (DSs) signaling drug availability. Compared to CS effects, DS effects are less explored in preclinical studies on cue-induced relapse. Objective: We compared CS and DS effects on reward seeking following abstinence from intermittent-access cocaine (or sucrose) self-administration. Methods: During 15–20 intermittent-access sessions, rats self-administered i.v. cocaine or sucrose pellets paired with a light-tone CS. Cocaine/sucrose was available for 5-min (signalled by a light; DS+) and unavailable for 25 min (signalled by different lighting conditions; DS-), and this cycled for 4 h/session. Following abstinence, we measured cocaine/sucrose seeking under extinction triggered by CS and DS presentation, and instrumental responding reinforced by these cues. Results: Across intermittent-access sessions, rats increased lever pressing for cocaine or sucrose during DS+ periods and decreased responding during DS- periods. On days 2 and 21 of abstinence, only presentation of the DS+ or DS+ and CS combined elicited increased cocaine/sucrose-seeking behaviour (i.e., increased active lever presses). Presenting the DS- alongside the DS+ suppressed the increased cocaine-seeking behaviour otherwise produced by the DS+. Finally, on day 21 of abstinence, rats showed equivalent levels of lever pressing reinforced by the DS+ , CS and by the DS+ and CS combined, suggesting comparable conditioned reinforcing value. Conclusions: After intermittent self-administration, cocaine-associated DSs and CSs acquire similar conditioned reinforcing properties, but DSs more effectively trigger increases in drug seeking. [ABSTRACT FROM AUTHOR]

Rationale: Reward-associated cues can invigorate reward-seeking actions via Pavlovian-to-instrumental transfer (PIT). Glutamatergic neurotransmission mediates the appetitive effects of reward-associated cues. We characterized the expression of PIT and its mediation by metabotropic group II glutamate (mGlu2/3) receptor activity in female and male rats. Objectives: Across the sexes, we used PIT procedures to determine (i) cue-triggered increases in instrumental responding for water reward (experiment 1) and (ii) the respective influences of the mGlu2/3 receptor agonist LY379268 and thirst satiation on this effect (experiment 2). Methods: Water-restricted female and male Sprague–Dawley rats learned to lever press for water. Separately, they learned that one of two auditory stimuli predicts free water (CS + vs CS −). On PIT test days, the CS + and CS − were presented independent of instrumental responding, and we measured effects on lever pressing under extinction (no water). In experiment 1, we characterized PIT across the sexes. In experiment 2, we measured PIT after systemic LY379268 administration (0, 0.3 and 1 mg/kg) and thirst satiation, respectively. Results: Female and male rats showed similar PIT, with CS + but not CS − presentations potentiating water-seeking behaviour. LY379268 (1 mg/kg) attenuated CS + evoked increases in both water-associated lever pressing and conditioned approach to the water port. Thirst satiation attenuated both water-seeking and CS + evoked conditioned approach behaviour. Conclusions: The sexes show similar cue-triggered increases in reward seeking, and thirst satiation suppresses both water-seeking and cue-triggered anticipation of water reward. Finally, across the sexes, mGlu2/3 receptor activity mediates cue-triggered increases in reward seeking. [ABSTRACT FROM AUTHOR]

The Price equation is a mathematical expression of selectionist and non-selectionist pressures on biological, cultural, and behavioral change. We use it here to specify instrumental and noninstrumental behaviors as they arise within the context of the Pavlovian autoshaping procedure, for rats trained under reward certainty and reward uncertainty. The point of departure for this endeavor is that some portion of autoshaped behavior referred to as goal-tracking appears instrumental—a function of resource attainment (the individual approaches the location where the unconditioned stimulus is to be delivered). By contrast, some other portion of autoshaped behavior referred to as sign-tracking is noninstrumental—irrelevant to making contact with the to-be-delivered unconditioned stimulus. A Price equation model is proposed that unifies our understanding of Pavlovian autoshaping behavior by isolating operant and respondent influences on goal-tracking (instrumental) and sign-tracking (noninstrumental) behavior. [ABSTRACT FROM AUTHOR]

Gambling disorder is an impairing condition confounded by psychiatric co-morbidity, particularly with substance use and anxiety disorders. Yet, our knowledge of the mechanisms that cause these disorders to coalesce remains limited. The Incentive Sensitization Theory suggests that sensitization of neural "wanting" pathways, which attribute incentive salience to rewards and their cues, is responsible for the excessive desire for drugs and cue-triggered craving. The resulting hyper-reactivity of the "wanting' system is believed to heavily influence compulsive drug use and relapse. Notably, evidence for sensitization of the mesolimbic dopamine pathway has been seen across gambling and substance use, as well as anxiety and stress-related pathology, with stress playing a major role in relapse. Together, this evidence highlights a phenomenon known as cross-sensitization, whereby sensitization to stress, drugs, or gambling behaviors enhance the sensitivity and dopaminergic response to any of those stimuli. Here, we review the literature on how cue attraction and reward uncertainty may underlie gambling pathology, and examine how this framework may advance our understanding of co-mordidity with substance-use disorders (e.g., alcohol, nicotine) and anxiety disorders. We argue that reward uncertainty, as seen in slot machines and games of chance, increases dopaminergic activity in the mesolimbic pathway and enhances the incentive value of reward cues. We propose that incentive sensitization by reward uncertainty may interact with and predispose individuals to drug abuse and stress, creating a mechanism through which co-mordidity of these disorders may emerge. [ABSTRACT FROM AUTHOR]

Pavlovian cues associated with junk-foods (caloric, highly sweet, and/or fatty foods), like the smell of brownies, can elicit craving to eat and increase the amount of food consumed. People who are more susceptible to these motivational effects of food cues may have a higher risk for becoming obese. Further, overconsumption of junk-foods leading to the development of obesity may itself heighten attraction to food cues. Here, we used a model of individual susceptibility to junk-foods diet-induced obesity to determine whether there are pre-existing and/or diet-induced increases in attraction to and motivation for sucrose-paired cues (ie, incentive salience or 'wanting'). We also assessed diet- vs obesity-associated alterations in mesolimbic function and receptor expression. We found that rats susceptible to diet-induced obesity displayed heightened conditioned approach prior to the development of obesity. In addition, after junk-food diet exposure, those rats that developed obesity also showed increased willingness to gain access to a sucrose cue. Heightened 'wanting' was not due to individual differences in the hedonic impact ('liking') of sucrose. Neurobiologically, Mu opioid receptor mRNA expression was lower in striatal 'hot-spots' that generate eating or hedonic impact only in those rats that became obese. In contrast, prolonged exposure to junk-food resulted in cross-sensitization to amphetamine-induced locomotion and downregulation of striatal D2R mRNA regardless of the development of obesity. Together these data shed light on individual differences in behavioral and neurobiological consequences of exposure to junk-food diets and the potential contribution of incentive sensitization in susceptible individuals to greater food cue-triggered motivation. [ABSTRACT FROM AUTHOR]

Technology can be thought of in two ways: as a set of tools that amplify or extend what we currently do (make it better, faster, stronger), or as something with the potential to radically change what we do or how we do it (Pea, R. D., Beyond amplification: Using the computer to reorganize mental functioning. Educational Psychologist 20: 167–182, 1985). As technological tools, e.g. the digital camera, become more common, teachers and students have increasingly integrated them into their work. This research attempts to answer two research questions about the digital camera as a technological tool in the science lab. Does the use of the digital camera in laboratory activities increase student learning? Does the use of the digital camera motivate students to take a greater interest in laboratory work? Two high school biology classes in an urban high school of 1300 students were used to carry out the study. One, the control group, did not use the digital camera during two lab activities, and the other, the experimental group did use the digital camera during the same lab activities. The results of the study indicated that the digital camera did increase student learning of process skills in the two biology lab activities. The results of unpaired t tests for independent data indicated the differences were statistically significant for the process questions, while the differences in responses to the content questions were not significantly different. Anecdotal evidence also indicated that the experimental group took more interest in setting up the apparatus and made fewer mistakes in the lab procedure than did the control group. [ABSTRACT FROM AUTHOR]

The paper presents a general critique of the use of conceptual frameworks in design, illustrated by the well known synchronous/asynchronous, co-located/non-co-located framework. It argues that while frameworks are a necessary and inevitable starting point for design, the business of tailoring and adapting them to specific situations need not be ad hoc. Triggering artefacts are a way of systematically challenging both designers' preunderstandings and the conservatism of work practice. Experiences from the Great Belt tunnel and bridge project are used to illustrate how triggering artefacts change the modality of designing for change. [ABSTRACT FROM AUTHOR]

Four criteria are discussed as important conditions of successful applications in Computer Supported Co-operative Work (CSCW). They are equality, mutual influence, new competence, and double-level language. The criteria originate in the experience of the International Co-operative Movement. They are examined and illustrated withreference to eight contemporary CSCW applications: meeting scheduling and support; bargaining; co-authoring; co-ordination; planning; design support and collaborative design. [ABSTRACT FROM AUTHOR]

A letter to the editor about the pathological processes associated with colorectal intussusception is presented.