An experimental evaluation of tokens as conditioned reinforcers in retarded children

Since the publication of experimental reports by Wolfe (1936) and Cowles (1937), that tokens could be established as conditioned reinforcers, many accounts have appeared on the implementation of token systems in human subjects. Tokens have been successfully used as prosthetic motivational devices in a great variety of situations and subjects, such as retarded children (Birnbrauer, Wolf, Kidder and Tague, 1965), adult psychotics (Ayllon and Azrin, 1969), delinquent children and adolescents (Tyler, 1967; Phillips and Wolf, 1968), low achievers in schools (Clark, Lachowicz and Wolf, 1968), emotionally disturbed children (Hewett, Taylor and Artuso, 1969) and in normal classroom settings (O'Leary, Becker, Evans and Saudargas, 1969). In these reports, administration of tokens usually produced an increase in the frequency of desirable social and productive behavior. However, none of these studies showed that the effect of the tokens depended on their role as conditioned reinforcers based on the standard exchange systems being used. No assessment was provided about the separate contribution of the social reinforcement operations involved in dispensing tokens in a social setting.A suggestion about the possible confounding effects of social reinforcement in token administration comes from the failure to establish token systems in subjects who are partially unresponsive to social reinforcement (Hamblin et al., 1970; Ribes and Souza e Silva, in preparation). The present research was conducted with the aim of isolating the effects of conditioned reinforcement as such—apart from those produced by the social reinforcement provided in the delivery of tokens.     

On objectivity

The following definition of objective is proposed: A statement S is objective if and only if in S all parameters that are relevant to its truth value are made explicit. The objectivity of predicates and relations can be defined in a similar manner. This simple conception of objectivity-which could be called explicitness conception of objectivity-can be found in Hermann Weyl and plays a central part in the natural sciences. There are grades of objectivity depending on the quality and the number of parameters our predicates are relativized to A relativistic Ockham principle has to be recognized: Relativization parameters are not to be multiplied beyond necessity. The explicitness conception of objectivity is accessible to mathematical specifications, is the core of the idea of invariance, has a lot of philosophical applications and leads to precise notions of subjectivity and a precise formulation of the problem of the limits of objectivity.I am grateful to Andreas Bartels, Ulrich Gähde, Mark Helme, Andreas Kamlah, Andreas Kemmerling, Winfred Klink, Toni Koch, Hilary Putnam and Matthias Varga von Kibéd who have, in one way or another, contributed to the present content and form of this paper.     

Social Change: Toward an Informed and Critical Understanding of Social Justice and the Capabilities Approach in Community Psychology

Community psychology has long been concerned with social justice. However, deployments of this term are often vague and undertheorized. To address this weakness in the field's knowledge body we explored John Rawls's theory of social justice and Amartya Sen's economic theory of the capabilities approach and evaluated each for its applicability to community psychology theory, research, and action. Our unpacking of the philosophical and political underpinnings of Rawlsian theory of social justice resulted in identifying characteristics that limit the theory's utility in community psychology, particularly in its implications for action. Our analysis of the capability approach proposed by Amartya Sen revealed a framework that operationalizes social justice in both research and action, and we elaborate on this point. Going beyond benefits to community psychology in adopting the capabilities approach, we posit a bi‐directional relationship and discuss how community psychology might also contribute to the capabilities approach. We conclude by suggesting that community psychology could benefit from a manifesto or proclamation that provides a historical background of social justice and critiques the focus on the economic, sociological, and philosophical theories that inform present‐day conceptualizations (and lack thereof) of social justice for community psychology.     

The effects of metabolic stress and vagotomy on emotional learning in an animal model of anxiety

The aim of the present study is to evaluate the role of the blood glucose (BG) level in emotional learning in the elevated plus maze (EPM), an animal model of anxiety. In Experiment 1, male Wistar rats were submitted to different EPM trial lengths (1- or 5-min). Blood samples were withdrawn before and after the maze exploration, through a polyethylene cannula chronically implanted into the jugular vein. In Experiment 2, the animals received either saline or 2-deoxy-D-glucose, a glucoprivic drug (2-DG, 250 or 500 mg kg(-1)) by i.p. route, 30 min before a 5-min EPM exposure and were retested in the maze (Trial1/Trial2 EPM procedure) 24 h later. In an independent group of rats, blood samples were withdrawn 0, 5, 15, and 30 min after 2-DG administration, through the jugular vein, to determine BG. In Experiment 3, the animals underwent a vagotomy and were tested in a Trial1/Trial2 EPM procedure four weeks later. The results showed that rats exploring the EPM for 5 min displayed increased fear and higher hyperglycemia than those exploring the EPM for 1 min. In addition, rats submitted to 5-min EPM Trial1 length displayed higher level of fear on Trial2, as well as higher percentage of shortening of the %Open arm entries and %Open arm time from Trial1 to Trial2, which characterizes the occurrence of emotional learning. In contrast, rats previously vagotomized or treated with 2-DG (500 mg kg(-1)) showed the same level of fear on both EPM trials and a low percentage of shortening, from Trial1 to Trial2, of the %Open arm entries and %Open arm time, indicating poor emotional learning. The data is discussed regarding the role of glycaemia in emotional learning in the EPM.     

Historical change of suicide seasonality in the canton of zurich, Switzerland

Current research is yielding an increasingly heterogeneous picture of suicide seasonalities: They seem to depend on methods and, moreover, they seem to have smoothed in recent decades. This work examines the latter issue by comparing suicide seasonalities in the canton of Zurich, Switzerland, in the 16 th -18 th centuries, 1901-1920 and 1969-94. The results indicate shifts of peaks and lows on suicide seasonalities over the centuries, with a smoothing of seasonalities toward the 21 th century. The recent period does not show any suicide seasonality at all. The canton of Zurich seems to be ahead of the general trend found in other regions of Switzerland.     

Trust in hybrid human-automated decision-support

Research has examined trust in humans and trust in automated decision support. Although reflecting a likely realization of decision support in high-risk tasks such as personnel selection, trust in hybrid human-automation teams has thus far received limited attention. In two experiments (N₁ = 170, N₂ = 154) we compare trust, trustworthiness, and trusting behavior for different types of decision-support (automated, human, hybrid) across two assessment contexts (personnel selection, bonus payments). We additionally examined a possible trust violation by presenting one group of participants a preselection that included predominantly male candidates, thus reflecting possible unfair bias. Whereas fully-automated decisions were trusted less, results suggest that trust in hybrid decision support was similar to trust in human-only support. Trust violations were not perceived differently based on the type of support. We discuss theoretical (e.g., trust in hybrid support) and practical implications (e.g., keeping humans in the loop to prevent negative reactions).