vol. 13 núm. 2 (2018): cognición comparada

Conditional self-discrimination is the learned ability that animals have shown to discriminate aspects of the individual, such as their own behavior, their own internal states or their own image. This concept corresponds to the behavioral version of self-awareness. Some authors suggest that this process have a phylogenetic course and depends on the social structure of the species. However, we have not detected research on its ontogenetic course. This study aimed to explore experimentally the relationship between age and the acquisition of conditional self-discrimination. In particular, a matching-to-sample experimental paradigm of conditional discrimination of the spatial orientation of the own behavior in rats was developed in a symmetric Y-maze. This type of labyrinth allows controlling external keys of spatial orientation, in addition to allow sequences of trials followed without the intervention of the experimenter. A first pilot study was conducted with eight adult subjects of the Wistar strain (weeks 19 to 32 of age) and, subsequently, the experimental study was carried out with the four young subjects (weeks 7 to 23 of age). Comparison stimuli associated with spatial orientation of the own behavior ("previous turn to the left" vs. "previous turn to the right") were geometric figures (triangle vs. circle) of yellow color on a black background. Discrimination index required to demonstrate acquisition was 0.8 in at least one trial. In the pilot study, six of eight adult subjects achieved the required level, while, in the experimental group, three of four young subjects achieved the criterion. Although both groups showed a tendency to acquire conditional self-discrimination, the acquisition rhythms were different according to age, consistent with the inverted U hypothesis of the ontogeny of learning, that is: younger subjects learn more slowly than adult ones. However, to complete the test of such hypothesis, an additional study is required with older subjects. Our ontogenetic findings complement the comparative studies of animal self-awareness, which give clues of the phylogeny of this process.

The work we present aims to clarify what is a context in the cognitive psychology of reasoning. Although the term context is found in the literature of different cognitive psychologists, we will argue that there is no clear analysis of what should be understood by that term. We will defend that the notion of context refers to different ideas, that is, the content, the format, the perspective, the nature of the logical contents and the environment of the problems. We will suggest that while these ideas may have overlaps, it is unclear that content, format, perspective, nature of logical content and environment are equivalent notions. Making these distinctions, we will argue, can not only help you understand what a context means, but it can also help you better understand the debates about how we humans reason or how we should reason.

Temporal Weighting Rule (TWR) is a model of foraging that can make predictions about integration and comparison of long term memories. These predictions have been demonstrated recently in animals and humans. The aim of this study is to replicate and extend the TWR predictions in child using a search-find virtual task with interactive figures. Preschoolers children searched two consequences with two magnitudes in two successive containers A and B, in three experimental conditions (A<B, A=B and A>B). Finally, during a test they chose between A or B after 24h interval (A<B 24 h, A=B 24h and A>B 24h) or immediately after training (A<B 0h, A=B 0h and A>B 0h). According to each condition, children could obtain higher (A>B), less (A<B) or equal (A=B) magnitude for each consequence during first or second experience of training. The results showed that child make a choice based in the time elapsed and they show dynamic average of both phases. The results suggest that TWR is a model that allows to describe and predict memory integration of spatial and temporal events in animals and humans.

Object permanence, the ability to represent hidden objects, has not been extensively assessed in cetaceans and the available evidence is contradictory. Although bottlenose dolphins (Tursiops truncatus) are thought to be endowed with cognitive capacities required to pass complex object permanence tests, they have failed a series of tasks involving invisible displacements, which raises the question of whether they do master object permanence. Lack of understanding of containment or lack of experience tracking objects hidden from both sight and echolocation may explain such unexpected results. The goal of the current study was to test these two hypotheses in a series of visible and invisible displacement tasks with bottlenose dolphins. Our results suggest that dolphins are indeed able to succeed in complex object permanence tasks but only if they have previous visual experience with the movements of objects inside other objects. Thus, these outcomes point to an important role of visual experience in the development of object permanence skills.

Los seres humanos tenemos comportamiento, cognición y emociones, gracias a que somos animales. Sin em-bargo, durante milenios, la psicología filosófica occidental se vio atrapada en un miope solipsismo. Por ejemplo, en el dualismo cartesiano, los seres humanos se distinguieron de los animales justamente por su capacidad de pensamiento consciente (res cogitans), mientras que los animales se restringieron a ser concebidos como má-quinas fisiológicas (res extensa) que funcionan por reflejo.

In the present study was assessed the effect of ¨social¨ facilitation and ¨social¨ interference in a situation of food intake in groups of rats of 2 to 8 members. The analyzed measurements were the differential weight, time of intake and rate of intake. There was fitted to a power function and to a linear function to the data of each measurement. The best fit to the data was determined with the explained variance level (R2). It was observed that the power function had a greater explained variance for the differential weight and time of intake. Nevertheless, in the intake rate, the function that best described the trend of the data was linear one. Additionally, when the trend of this last measurement was analyzed, the magnitudes of the effects of facilitation and interference were determined, complementing the information obtained from other measurements. Lastly, the results obtained had coincidence with the reports of Castro & Brewer (1992) in a study of feeding with humans. The paper emphasizes that in situations of collective feeding, the type of analyzed measurements may give rise to different trend of data but its interpretation has to be reviewed based on its particular characteristics.

In classical conditioning, an animal is exposed to a neutral stimulus (conditioned stimulus) followed by an appe-titive or aversive stimulus (unconditioned stimulus). With successive repetitions of this association, the animal will respond to the neutral stimulus as if it were the unconditioned stimulus. This phenomenon has been widely explored in different zoological classes, covering animal species ranging from mollusks to humans. In most ca-ses, appetitive and aversive unconditioned stimuli correspond to different sensory pathways. For example, the appetitive stimulus typically used is food and the typical aversive stimulus is electric shock. Thus one type of sti-mulus will excite the receptors related to the sense of taste, while the other type will do so mostly on the tactile and nociceptive pathways. Studies on amphibians, particularly the terrestrial toad, reproduce to a large extent the findings in other animal species,  but they have characteristics that make them unique by having electrolyte receptors in their skin that are involved in the regulation of their body's hydrosaline balance. A toad exposed to a slightly hypertonic saline solution (concentration less than 250 mMNaCl) gains weight and exhibits approxi-mation behaviors. Whereas if it takes contact with a highly hypertonic saline solution (concentration higher than 400 mM NaCl), it loses weight and exhibits escape behaviors. Thus, the same stimulus (a saline solution of NaCl), can act as an appetitive or aversive stimulus depending on its concentration. This particularity has been called unidimensionality of motivational stimuli. In the present work we describe the procedures and review the results of associative learning studies in toads, highlighting the use of this experimental model for the study of the possible neural mechanisms involved in the processing of appetitive and aversive environmental signals.    

Amphibians are a phylogenetically very old group that is characterized by being the representatives of the transition from the aquatic to the terrestrial environment, with all the implications that this could have on the organization of its nervous system. e use of this animal model to study the spatial cognitive evolution, offers the advantage of having a simple nervous system, without a neocortex, which allows inquire about the basic brain circuits that underlie this behavior. Employing a comparative approach, this article describes several pro-cedures and experimental devices used for the study of spatial orientation and navigation abilities in amphi-bians, as well as its neural bases. Spatial learning is essential for individuals’ survival, being able to include strategies involving environmental visual cues and self-referential information. Taking into account all the information accumulated to date in amphibians, both in laboratory controlled conditions and in natural envi-ronments, it is possible to conclude that the properties of this cognitive ability have been largely conser-ved throughout evolution.