Adriana Jakovcevic

Breed differences in dogs’ (Canis familiaris) gaze to the human face

Domestic dogs (Canis familiaris) have been submitted to a vast process of artificial selection and to date, there are hundreds of breeds that differ in their physical and behavioral features. In addition, dogs possess important skills to communicate with humans. Previous evidence indicates that those abilities are related to the domestication process and are modulated by instrumental learning processes. Very few studies, however, have evaluated breed differences in the use and learning of interspecific communicative responses. In Study 1 Retrievers, German Shepherds and Poodles were compared in the acquisition and extinction of their gaze toward the human face, in a conflict situation involving food within sight but out of reach. The groups did not differ in the acquisition of the response, but throughout the extinction phase Retrievers gazed to the human significantly more than the other groups. In Study 2, similar results were obtained in a test without any previous explicit training. These results suggest that these three major popular breeds differ in gazing to humans in a communicative situation.

Incentive Contrast in Domestic Dogs (Canis familiaris)

Dogs (Canis familiaris) trained to receive a preferred food (dry beef liver) from an experimenter learned to maintain a longer gaze on the experimenter than dogs receiving a less preferred food (dog pellets). Dogs downshifted from dry liver to pellets rejected food more frequently than nonshifted controls. Gaze duration also decreased in downshifted dogs below the level of a group always reinforced with pellets. In addition, downshifted dogs tended to move away from the experimenter, adopting a lying down posture. This phenomenon, called successive negative contrast, has been described in analogous experiments with a variety of mammalian species, but has failed to occur in similar experiments with nonmammalian vertebrates. Unlike similar previous observations, the present data were obtained in an environment involving interspecific communication.

Frustration Behaviors in Domestic Dogs

During extinction a previously learned behavior stops being reinforced. In addition to the decrease in the rate of the instrumental response, it produces an aversive emotional state known as frustration. This state can be assimilated with the fear reactions that occur after aversive stimuli are introduced at both the physiological and behavioral levels. This study evaluated frustration reactions of domestic dogs (Canis familiaris) during a communicative situation involving interactions with a human. The task included the reinforcement and extinction of the gaze response toward the experimenters face when the dogs tried to obtain inaccessible food. The dogs frustration reactions during extinction involved an increase in withdrawal and side orientation to the location of the human as well as lying down, ambulation, sniffing, and vocalizations compared with the last acquisition trial. These results are especially relevant for domestic dog training situations in which the extinction technique is commonly used to discourage undesirable behaviors.

O Uso da Bicicleta como Meio de Transporte: Influência de Fatores Psicológicos. Uma Revisão de Literatura

El uso masivo de transportes sustentables como la bicicleta, no solo requieren cambios en la infraestructura de las ciudades sino un cambio en el comportamiento. En funcion de ello, resulta necesario conocer cuales son las motivaciones que determinan la eleccion de este medio de transporte. El objetivo del trabajo fue analizar cuales son las variables psicologicas que mejor predicen el uso de la bicicleta como modo de transporte, mediante una revision sistematica de la literatura de los ultimos 10 anos. Los resultados de nuestro analisis indicaron que la eleccion de la bicicleta como medio de transporte se encuentra determinada por procesos intencionales. La intencion de usar este medio principalmente se asocia a la percepcion de apoyo social asi como a la percepcion de las propias habilidades para ejecutar la conducta (autoeficacia) y en menor medida, a una actitud positiva hacia la misma. No obstante, una vez que trasladarse en bicicleta se ha convertido en una conducta habitual, la influencia de los procesos racionales se debilita. Esto sugiere que en el diseno de politicas destinadas a incrementar la movilidad sustentable se deben contemplar estrategias diferenciadas de acuerdo a la frecuencia de uso de este modo de transporte.