Visual symmetry recognition by pigeons

Summary Pigeons learned to discriminate a large number of bilateral symmetric and asymmetric visual patterns successively projected on the pecking-key of an operant conditioning chamber. Responses to the positive stimuli were reinforced according to a variable interval schedule. Once acquisition was complete generalization trials, involving sets of new stimuli, were instituted under extinction. The birds classified these novel test stimuli with high accuracy throughout, according to their symmetry or asymmetry. Their performance was not disturbed by sets of test stimuli whose geometrical style differed considerably from the training stimuli. Pigeons were even able to discriminate when only allowed the use of one eye. The generalization series were partly designed to test some classical symmetry recognition theories. None was found to be adequate. Subsidiary experiments suggested that most pigeons have a slight spontaneous preference for asymmetric patterns and that symmetry/asymmetry differences can aid pattern discrimination learning at an early stage. It is concluded that pigeons, much like humans, can discriminate bilaterally symmetric from non-symmetric visual forms in a concept-like, generalizing way. The ontogenetic and phylogenetic development of this competence is considered. A novel symmetry recognition hypothesis based on spatial frequency analysis and neuronal feature-detector considerations is proposed.     

Dissociative effects of different types and amounts of nonreinforced CS exposure on avoidance extinction and the CER

Two experiments examined the effectiveness of two amounts of flooding or response-prevention on hastening avoidance response extinction and on reducing CS-produced suppression of bar-pressing for food. In Experiment 1, 20 and 30 flooding trials were both shown to be effective in hastening the extinction of a well-learned shuttlebox avoidance response. In Experiment 2, rats trained under comparable conditions to those in Experiment 1 were tested following flooding for the CER in a different apparatus. The results indicated that 30, but not 20, flooding trials were sufficient to reduce the CER. In each experiment the results of additional control groups equated with the flooded groups for nonreinforced CS exposure also revealed a dissociation between the effectiveness of this CS time control procedure in hastening avoidance response extinction and in reducing the CER. Further comparisons showed that although 30 flooding trials did reduce the CER, the same total duration of nonreinforced CS Exposure in the form of avoidance extinction trials did not. Thus the context in which CS exposure occurs may affect the dynamics of extinction of the CER. The experiments are discussed in the broader context of dissociation of various indices of fear in humans.     

Demonstration of an aftereffect occurring in the tactile-kinesthetic domain

Summary The aim of this work is the demonstration of a tactile-kinesthetic aftereffect. A sequence of stimuli was offered to adult subjects whose task was to compare two weights presented simultaneously to both hands by means of a Piéron gravimeter. In Experiment 1 the inspection stimuli consisted of two successive presentations of unequal weights for a period of 2 × 10 s. The test stimuli consisted of two equal weights rapidly following an inspection stimulus. Control stimuli consisting of two equal weights not preceded by an inspection stimulus were interspersed in the sequence. The results obtained confirm the existence of a contrast effect after presentation of an inspection stimulus. In Experiment 2 the inspection stimuli consisted of a single presentation of two unequal weights for a period of 20 s. The results confirm those of the first experiment and provide data enabling the contrast effect obtained to be interpreted as a Köhler-type aftereffect. In order to avoid confusion with the kinesthetic-figural aftereffect, we propose to call the effect demonstrated here the Gravimetric Aftereffect.     

Human Self-Domestication and the Evolution of Pragmatics

As proposed for the emergence of modern languages, we argue that modern uses of languages (pragmatics) also evolved gradually in our species under the effects of human self-domestication, with three key aspects involved in a complex feedback loop: (a) a reduction in reactive aggression, (b) the sophistication of language structure (with emerging grammars initially facilitating the transition from physical aggression to verbal aggression); and (c) the potentiation of pragmatic principles governing conversation, including, but not limited to, turn-taking and inferential abilities. Our core hypothesis is that the reduction in reactive aggression, one of the key factors in self-domestication processes, enabled us to fully exploit our cognitive and interactional potential as applied to linguistic exchanges, and ultimately to evolve a specific form of communication governed by persuasive reciprocity—a trait of human conversation characterized by both competition and cooperation. In turn, both early crude forms of language, well suited for verbal aggression/insult, and later more sophisticated forms of language, well suited for persuasive reciprocity, significantly contributed to the resolution and reduction of (physical) aggression, thus having a return effect on the self-domestication processes. Supporting evidence for our proposal, as well as grounds for further testing, comes mainly from the consideration of cognitive disorders, which typically simultaneously present abnormal features of self-domestication (including aggressive behavior) and problems with pragmatics and social functioning. While various approaches to language evolution typically reduce it to a single factor, our approach considers language evolution as a multifactorial process, with each player acting upon the other, engaging in an intense mutually reinforcing feedback loop. Moreover, we see language evolution as a gradual process, continuous with the pre-linguistic cognitive abilities, which were engaged in a positive feedback loop with linguistic innovations, and where gene-culture co-evolution and cultural niche construction were the main driving forces.     

May the odds be ever in your favor: The Hunger Games and the fight for a more equal society. (Negative) Media vicarious contact and collective action

Various studies have found that reading books about positive interactions between ingroup and outgroup characters, known as media vicarious contact, can reduce prejudice. Focusing on the fantasy saga of The Hunger Games, we examined the effects of negative vicarious contact on collective action across two studies. Specifically, we tested whether reading about fantasy characters living in a postapocalyptic conflictual society with large social disparities between advantaged and disadvantaged groups leads advantaged group members to display greater willingness to engage in collective action on behalf of the disadvantaged group. Results from Study 1 (correlational survey in the United Kingdom and United States) and Study 2 (experimental intervention in Italy) revealed that reading The Hunger Games is indirectly associated with greater collective action intentions via increased anger toward injustice. In both studies social dominance orientation (SDO) acted as a moderator, but in opposite directions: mediation was significant for low-SDOs in Study 1, and for high-SDOs in Study 2. Results are discussed in relation to the importance of media vicarious contact via book reading for social change, and to the need to identify the contextual conditions allowing to anticipate the specific moderation pattern that is more likely to emerge.     

Family and food variables that influence life satisfaction of mother-father-adolescent triads in a South American country

This study explored the influence of each family member’s life satisfaction on the other family members’ life satisfaction in mother-father-adolescent triads. We also explored the influence of each family member’s satisfaction with food-related life and family life on their own life satisfaction (LS) as well as on the other family members’ LS in mother-father-adolescent triads. The influence of family eating habits, food-related parenting practices used by each parent and sociodemographic characteristics on each family member’s LS were also explored. A survey was applied to a sample of 300 two-parent families with one child between 10 and 17 years of age in Temuco, Chile. The questionnaire included the Satisfaction with Life Scale, Satisfaction with Food-related Life scale, Satisfaction with Family Life scale, Adapted Healthy Eating Index, Family Food Behavior Survey and Family Eating Habits Questionnaire. Frequency and sources of family meals as well as sociodemographic characteristics were also consulted. Three multivariate ordinal logit models were proposed, with the dependent variable LS in the three subsamples: mothers, fathers and adolescents. The three logit models were significant, but differed in the explanatory variables. Mothers’ LS was influenced by their children’s LS and vice versa. Mothers’ LS was positively influenced by both their own satisfaction with family life and the fathers’ satisfaction with family life and vice versa. Children’s LS was also positively influenced by their own satisfaction with food-related and family life. Both parents’ LS was influenced by eating habits, food-related parenting practices and sociodemographic characteristics, but in different ways. Therefore, different interventions should be implemented to improve each family member’s life satisfaction.

     

Examining the psychometric properties of the burnout clinical subtype questionnaire (BCSQ-12) in secondary school teachers

Current Psychology - Based on Farber’s burnout proposal, the first aim of this study was to examine the psychometric properties of the short version of the Burnout Clinical Subtype...     

Navigating in a challenging semiarid environment: the use of a route-based mental map by a small-bodied neotropical primate

To increase efficiency in the search for resources, many animals rely on their spatial abilities. Specifically, primates have been reported to use mostly topological and rarely Euclidean maps when navigating in large-scale space. Here, we aimed to investigate if the navigation of wild common marmosets inhabiting a semiarid environment is consistent with a topological representation and how environmental factors affect navigation. We collected 497 h of direct behavioral and GPS information on a group of marmosets using a 2-min instantaneous focal animal sampling technique. We found that our study group reused not only long-route segments (mean of 1007 m) but entire daily routes, a pattern that is not commonly seen in primates. The most frequently reused route segments were the ones closer to feeding sites, distant to resting sites, and in areas sparse in tree vegetation. We also identified a total of 56 clustered direction change points indicating that the group modified their direction of travel. These changes in direction were influenced by their close proximity to resting and feeding sites. Despite our small sample size, the obtained results are important and consistent with the contention that common marmosets navigate using a topological map that seems to benefit these animals in response to the exploitation of clustered exudate trees. Based on our findings, we hypothesize that the Caatinga landscape imposes physical restrictions in our group’s navigation such as gaps in vegetation, small trees and xerophytic plants. This study, based on preliminary evidence, raises the question of whether navigation patterns are an intrinsic characteristic of a species or are ecologically dependent and change according to the environment.

     

How do Mandarin speakers conceptualize time? Beyond the horizontal and vertical dimensions

Cognitive Processing - Mandarin speakers, similar to speakers of most other languages around the world, tend to conceptualize time in terms of space. However, it has been supposed that Mandarin...