A positional coding mechanism in pigeons after learning multiple three-item lists

Pigeons were trained on three three-item lists (List 1: A₁ → B₁ → C_1; List 2: A₂ → B₂ → C_2; List 3: A₃ → B₃ → C₃). After sessions in which any one of the three lists could be presented on a trial, derived-maintained list and derived-changed list probe trials were introduced. The derived list probe trials were composed of three items, one drawn from each of the training lists. On derived-maintained probe trials, each item was in the same ordinal position it occupied during training (e.g., A₃ → B₁ → C₂). On derived-changed probe trials, items that occupied the second and third position during training were exchanged (e.g., A₂ → C₃ → B₁). The performance of subjects on derived-maintained probe trials was significantly above chance and no different to that observed on the training lists. In contrast, subjects’ performance on derived-changed probe trials was significantly below chance. To our knowledge, this is the first study that has demonstrated pigeons are able to learn and retain multiple three-item lists. In addition, subjects’ performance on the derived-maintained probe trials suggests that they acquire knowledge of each list item’s ordinal position when learning multiple lists.     

Agent-based Theories of Right Action

In this paper, I develop an objection to agent-based accounts of right action. Agent-based accounts of right action attempt to derive moral judgment of actions from judgment of the inner quality of virtuous agents and virtuous agency. A moral theory ought to be something that moral agents can permissibly use in moral deliberation. I argue for a principle that captures this intuition and show that, for a broad range of other-directed virtues and motives, agent-based accounts of right action fail to satisfy this principle.     

Pathogens, personality, and culture: disease prevalence predicts worldwide variability in sociosexuality, extraversion, and openness to experience

Previous research has documented cross-cultural differences in personality traits, but the origins of those differences remain unknown. The authors investigate the possibility that these cultural differences can be traced, in part, to regional differences in the prevalence in infectious diseases. Three specific hypotheses are deduced, predicting negative relationships between disease prevalence and (a) unrestricted sociosexuality, (b) extraversion, and (c) openness to experience. These hypotheses were tested empirically with methods that employed epidemiological atlases in conjunction with personality data collected from individuals in dozens of countries worldwide. Results were consistent with all three hypotheses: In regions that have historically suffered from high levels of infectious diseases, people report lower mean levels of sociosexuality, extraversion, and openness. Alternative explanations are addressed, and possible underlying mechanisms are discussed.     

The Research Studies on Quality of Life in South America

Applied Research in Quality of Life - Concentrating on South America, we may assert that this region has been both object and producer of studies on quality of life, on the basis of research papers...     

What's in a name? Typicality and relatedness effects in children

We studied how category typicality and out-of-category relatedness affect speeded category verification (vote "yes" if pictured object is clothing) in typically developing 4- to 14-year-olds and adults. Stimuli were typical and atypical category objects (e.g., pants, glove) and related and unrelated out-of-category objects (e.g., necklace, soup). Typical and unrelated out-of-category objects exhibited preferential processing (faster reaction times and fewer errors). Variations in typicality and relatedness disproportionately influenced children's performance, with developmental improvement associated with both verbal and nonverbal factors. Underextension versus overextension errors seemed to be associated with independent factors, namely multifaceted maturational factors versus receptive vocabulary skill, respectively. Errors were infrequent, suggesting spontaneous taxonomic classification by all participants. An experiment with printed words in adults replicated results, indicating that typicality and relatedness effects reflected organizational principles of the semantic system, not picture-related processes. This research establishes the viability of an online approach to assessing automatic components of semantic organization in children.     

Long-lasting semantic context effects in the spoken production of object names

A number of recent studies have found that objects are named more slowly in the context of same-category items than in the context of items from various semantic categories. Several experiments reported here indicated that this semantic effect is relatively persistent because it was essentially unaffected by the presence of interspersed filler items. The authors suggest that the effect is specific to the retrieval of lexical-semantic codes and characterize mechanisms that could support the effect at this processing level, such as incremental learning in the links between conceptual and lexical codes and the temporary increase of lexical resting levels. The results underscore the necessity of incorporating mechanisms of long-term adaptation into current models of spoken production.     

The role of partial knowledge in statistical word learning

A critical question about the nature of human learning is whether it is an all-or-none or a gradual, accumulative process. Associative and statistical theories of word learning rely critically on the later assumption: that the process of learning a word’s meaning unfolds over time. That is, learning the correct referent for a word involves the accumulation of partial knowledge across multiple instances. Some theories also make an even stronger claim: Partial knowledge of one word–object mapping can speed up the acquisition of other word–object mappings. We present three experiments that test and verify these claims by exposing learners to two consecutive blocks of cross-situational learning, in which half of the words and objects in the second block were those that participants failed to learn in Block 1. In line with an accumulative account, Re-exposure to these mis-mapped items accelerated the acquisition of both previously experienced mappings and wholly new word–object mappings. But how does partial knowledge of some words speed the acquisition of others? We consider two hypotheses. First, partial knowledge of a word could reduce the amount of information required for it to reach threshold, and the supra-threshold mapping could subsequently aid in the acquisition of new mappings. Alternatively, partial knowledge of a word’s meaning could be useful for disambiguating the meanings of other words even before the threshold of learning is reached. We construct and compare computational models embodying each of these hypotheses and show that the latter provides a better explanation of the empirical data.     

Zoonotic and non-zoonotic diseases in relation to human personality and societal values: Support for the parasite-stress model

The parasite-stress model of human sociality proposes that humans' ontogenetic experiences with infectious diseases as well as their evolutionary historical interactions with these diseases exert causal influences on human psychology and social behavior. This model has been supported by cross-national relationships between parasite prevalence and human personality traits, and between parasite prevalence and societal values. Importantly, the parasite-stress model emphasizes the causal role of non-zoonotic parasites (which have the capacity for human-to-human transmission), rather than zoonotic parasites (which do not), but previous studies failed to distinguish between these conceptually distinct cate- gories. The present investigation directly tested the differential predictive effects of zoonotic and non-zoonotic (both human-specific and multihost) parasite prevalence on personality traits and societal values. Supporting the parasite-stress model, cross-national differences in personality traits (unrestricted sexuality, extraversion, openness to experi- ences) and in societal values (individualism, collectivism, gender equality, democratiza- tion) are predicted specifically by non-zoonotic parasite prevalence.     

Does variability in human performance outweigh imprecision in response devices such as computer keyboards?

In chronometric research, it is well-known that many response devices used with personal computers, especially computer keyboards, suffer from measurement inaccuracies due to infrequent polling. In this article, it is investigated whether it is worth being concerned by this added error, given that human performance inherently exhibits a considerable degree of variability. By comparing inaccuracy due to response device imprecision with the level of variability already present in human performance, it is shown that the former is very unlikely to have a negative impact on statistical outcomes. In other words, millisecond resolution of response devices, although desirable, is not a general requirement.