Nativism and neurobiology: Representations, representing, and the continuum of cognition.

Whether or not the mind contains innately specified representations is highly contestable, especially in light of neurobiological evidence for the plasticity of the brain. In what follows, I provide an overview of the debate as it now stands and a discussion of the possibility, proposed by Clark (1998) and others, that representations need not be localized and are better understood as distributed systems. I then seek to tie the debate into a similar controversy surrounding the architecture of the mind. While advocates of modularity find arguments for innately specified and domain-specific representations palatable, as the thesis of innateness only strengthens their claims, favorers of a more domain-general learning mechanism are not convinced by arguments for innate specificity and instead insist that representations emerge or are learned. Rather than come down on one side of these issues, I propose, in the spirit of Cundall (2006), that cognition is more aptly conceived of as a continuum: the domains by which certain "representers" are constrained turn out to be innate, while many of the complex representations, in particular, higher-level social-cognitive representations, come from more general learning and development. Thus, the problem of reconciling nativism and neurobiology turns out to be a matter not of choosing one of two extremes, but instead, adopting an intermediary view. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The team identification–social psychological health model: Sport fans gaining connections to others via sport team identification.

Previous work has consistently found positive relationships between levels of sport team identification and social psychological well-being. According to the Team Identification–Social Psychological Health Model, these effects result from the increased social connections fans generate through their interest in the team. The current pair of investigations was designed to test the hypotheses that (1) team identification is positively related to social well-being and (2) team identification is positively related to social connections. In addition, the interrelationships among the variables were investigated (i.e., tests for mediation and moderation). In Study 1, a sample of 161 college students completed a questionnaire assessing demographics, identification with a local team, connections gained by following the team, and social well-being. Results indicated that, as expected, team identification was positively related to both well-being and social connections. Subsequent analyses failed to find evidence that social connections mediated or moderated the relationship between team identification and social psychological health. Study 2 (N = 199 students from the same university as Study 1) replicated the results of the initial study using a more general measure of social connections (i.e., the Campus Connectedness Scale). Discussion includes the implications for the Team Identification–Social Psychological Health Model and the directionality between identification and social connections. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Order information and retrieval distinctiveness: Recall of common versus bizarre material.

The order-encoding hypothesis (E. L. DeLosh & M. A. McDaniel, 1996) assumes that serial-order information contributes to the retrieval of list items and that serial-order encoding is better for common items than bizarre items. In line with this account, Experiment 1 revealed better free recall and serial-order memory for common than for bizarre items in pure lists, and Experiment 2 showed that recall for bizarre items increased and the recall advantage of common items was eliminated when serial-order encoding for bizarre items was increased to the level of common items. However, inconsistent with a second assumption that bizarre-item advantages in mixed lists reflect better individual-item encoding for bizarre items, Experiments 3 and 4 showed that the bizarreness effect in mixed lists is eliminated when alternative retrieval strategies are encouraged. This set of findings is better explained by the differential-retrieval-process framework, which proposes that contextual factors (e.g., list composition) influence the extent to which various types of information are used at retrieval, with the bizarreness advantage in mixed lists dependent on a distinctiveness-based retrieval process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lack of effects on heart rate and blood pressure inketamine-anesthetized rats briefly exposed to ultra-widebandelectromagnetic pulses

Fourteen Sprague-Dawley rats were exposed to pulses produced by a Bournlea ultra-wideband (UWB) pulse generator (rise time, 318-337 ps; maximum E field, 19-21 kV/m). Exposures at a repetition frequency of 1 kHz for 0.5 s or to repetitive pulse trains (2-s exposure periods alternating with 2 s of no exposure, for a total of 2 min) resulted in no significant changes in heart rate or mean arterial blood pressure. These results suggest that acute whole-body exposure to UWB pulses does not have a detrimental effect on the cardiovascular system     

Long-term, low-level exposure of mice prone to mammary tumors to 435 MHz radiofrequency radiation

Six hundred and thirty four interviews of injecting drug users were performed between 1992 and 1994 as part of a study of injecting drug use and HIV prevalence in Edinburgh, Scotland. Amphetamine was injected by more subjects (44%) than any other drug. Preference for injection as the route of administration of amphetamine increased over the period despite no change in the popularity of the drug generally. Simultaneously, heroin use and injection declined. Analyses indicated that amphetamine injectors comprised two distinct sub-groups. The majority were polydrug injectors who injected frequently, had a longer injecting history and were more likely to share injection equipment. About one-fifth were stimulant-only injectors who injected infrequently, were relatively recent initiates to injecting and whose numbers increased over the 3 years. Drug treatment and prevention services may need to explore alternative methods to respond effectively to these emerging trends.     

Secure reliable multicast protocols in a WAN

Summary. A secure reliable multicast protocol enables a process to send a message to a group of recipients such that all correct destinations receive the same message, despite the malicious efforts of fewer than a third of the total number of processes, including the sender. This has been shown to be a useful tool in building secure distributed services, albeit with a cost that typically grows linearly with the size of the system. For very large networks, for which this is prohibitive, we present two approaches for reducing the cost: First, we show a protocol whose cost is on the order of the number of tolerated failures. Secondly, we show how relaxing the consistency requirement to a probabilistic guarantee can reduce the associated cost, effectively to a constant. Received: August 1997 / Accepted: July 1999