Colamus humanitatem: Nurturing human nature

In an essay on anger, the ancient philosopher Seneca warns of the futility of harboring negative emotions given the imminence of death—the ultimate human equalizer. Ancient philosophers like Seneca believed that emotions are based on cognitions (beliefs) and are therefore modifiable through spiritual exercises. Modern research shows that the emotional and cognitive aspects of human psychology are malleable (nurture), but also require gene expression (nature). A parallel between individual behavior and socio-political forces suggests a framework for the current environmental crisis— another human equalizer. Two critical questions are suggested: Is the amassed experience of the last few centuries sufficient to lead to corrective measures that would avoid environmental degradation? Or would a catastrophic event with significant longterm environmental degradation have to occur before corrective measures reach consensus at the socio-political level? En un ensayo sobre la ira, el antiguo filósofo Séneca advierte lo inútil que es albergar emociones negativas, dada la inminencia de la muerte, condición que, en últimas, nos hace iguales como humanos. Los antiguos filósofos, creían que las emociones estaban basadas en cogniciones y que por eso eran modificables a través de ejercicios espirituales. Las investigaciones actuales demuestran que los aspectos cognitivos y emocionales de la  sicología humana son maleables (crianza), pero que también requieren expresión genética (naturaleza). Un paralelo entre el comportamiento individual y las fuerzas sociopolíticas sugiere un marco para la crisis ambiental actual, otro “ecualizador” humano. Dos preguntas críticas surgen: ¿Es suficiente la experiencia acumulada de los dos últimos siglos para conseguir medidas correctivas que puedan impedir la degradación ambiental? o ¿es necesario que ocurra un evento catastrófico de degradación ambiental significativa a largo plazo para que las medidas correctivas puedan alcanzar consenso en el nivel socio-político

Efectos de la ablación telencefálica sobre el aprendizaje apetitivo instrumental en la carpa dorada (Carassius auratus)

Efectos de la ablación telencefálica sobre el aprendizaje apetitivo instrumental en la carpa dorada (Carassius auratus). En este experimento se emplearon carpas doradas (Carassius auratus) con ablación bilateral del telencéfalo o con operación de control en un procedimiento de entrenamiento instrumental con distribución de ensayos ampliamente espaciados (un ensayo por día). Los animales fueron entrenados a nadar en un corredor bajo condiciones de reforzamiento continuo o reforzamiento parcial al 50%. Se realizaron 32 sesiones diarias de adquisición seguidas de 32 sesiones diarias de extinción en las que la comida fue suprimida. La lesión telencefálica afectó a la adquisición durante los primeros ensayos, aunque, al final, los animales lesionados alcanzaron una ejecución asintótica similar a la de los animales controles. La extinción se vio facilitada por las lesiones, independientemente del programa de reforzamiento usado durante la adquisición. Los resultados se interpretan en relación a los estudios comparativos de aprendizaje instrumental apetitivo con ensayos espaciados realizados en otros vertebrados.Goldfish received either bilateral ablation of the telencephalon or a sham operation, followed by instrumental training under widely-spaced conditions (one trial per day). Animals were trained to swim in a runway for either continuous reinforcement or 50% partial reinforcement. Thirty-two daily acquisition sessions were followed by 32 daily extinction sessions during which food was withheld. Telencephalic lesions disrupted early acquisition performance, but lessoned animals achieved an asymptotic performance similar to that of sham controls. Extinction was facilitated by the lesions, independently of the schedule of reinforcement used during acquisition. The results are interpreted in relation to comparative research on spaced-trial appetitive instrumental learning in vertebrates.Ministerio de Educación y Cultura PB96-1334Junta de Andalucía CVI-24

Un análisis de los efectos ansiolíticos del etanol sobre el contraste negativo sucesivo consumatorio

The anxiolytic properties of ethanol (1 g/kg, 15% dose, i.p.) were studied in two experiments with rats involving incentive downshifts from a 32% to a 4% sucrose solution. In Experiment 1, alcohol administration before a downshift from 32% to 4% sucrose prevented the development of consummatory suppression (consummatory successive negative contrast, cSNC). In Experiment 2, ethanol prevented the attenuating effects of partial reinforcement (random sequence of 32% sucrose and nothing) on cSNC, causing a retardation of recovery from contrast. These effects of ethanol on cSNC are analogous to those described for the benzodiazepine anxiolytic chlordiazepoxide, suggesting that at least some of its anxiolytic effects are mediated by the same mechanisms. Las propiedades ansiolíticas del etanol (1 g/kg, dosis de 15% intraperitoneal) fueron estudiadas en dos experimentos con ratas que fueron expuestas a una disminución sorpresiva del incentivo, una solución azucarada, del 32% al 4%. En el Experimento 1, la administración del alcohol antes del cambio negativo de 32% a 4% previno el desarrollo de la supresión consumatoria (contraste sucesivo negativo consumatorio, CSNc). En el experimento 2, el etanol previno los efectos atenuantes del reforzamiento parcial (consistente en una secuencia aleatoria de solución azucarada al 32% o agua sin azúcar) sobre el CSNc, causando un retardo en la recuperación del contraste. Estos efectos del etanol sobre el CSNc son análogos a aquellos descritos para la benzodiazepina ansiolítica clordiazepóxido, sugiriendo que al menos sus efectos ansiolíticos están mediados por el mismo mecanismo.

Effects of pretraining treatment with testosterone on successive and anticipatory negative contrast

Previous research indicated that the suppression of consummatory behavior that follows incentive downshift in male rats is attenuated by testosterone (T) administration during training. The present experiments were designed to assess the role of pretraining T administration on two incentive contrast situations in consummatory behavior: successive negative contrast (cSNC) and anticipatory negative contrast (cANC). In cSNC (Experiment 1), a downshift from 32% to 4% sucrose leads to behavioral suppression relative to an unshifted, 4% sucrose condition (the cSNC effect). Pretraining T administration enhanced consummatory behavior directed at 4% sucrose, without affecting behavior directed at 32% sucrose. This effect obscured a reduction in the cSNC effect by the T treatment that was only detected when a proportional measure of behavior was used. In cANC (Experiment 2), groups received access to two bottles per day separated by a short midtrial interval. Consumption of 4% sucrose is suppressed when the second bottle offers 32% sucrose, relative to 4% sucrose (the cANC effect). Pretraining T did not affect the cANC effect, known to be insensitive to treatment with anxiolytics. These results suggest an anxiolytic-like effect of testosterone in adjustment to incentive downshifts

Reexamining the frustration effect in rats: Aftereffects of surprising reinforcement and nonreinforcement.

Abstract The reinforcement-omission effect (ROE; also called frustration effect), or greater response strength immediately after nonreinforcement (N) than reinforcement (R), has been traditionally interpreted in terms of one of two factors: transient facilitation after N induced by primary frustration or transient suppression after R induced by postconsummatory processes. Three instrumental lever-pressing experiments with rats demonstrated that the ROE can be caused by either factor in isolation, or by both acting simultaneously. The distribution of trials and the interval between N or R and the target response determine which factor would cause the ROE. Both aftereffects decay in time, but the after-N process decays at a slower rate than the after-R factor. Ó 2003 Elsevier Inc. All rights reserved. In 1952 Amsel and Roussel reported a runway experiment that demonstrated (or so they thought) that the surprising omission of an appetitive reinforcer was followed by behavioral invigoration. In that experiment, rats received training in a double Learning and Motivation 34 (2003

Incentive or Habit Learning in Amphibians?

Toads (Rhinella arenarum) received training with a novel incentive procedure involving access to solutions of different NaCl concentrations. In Experiment 1, instrumental behavior and weight variation data confirmed that such solutions yield incentive values ranging from appetitive (deionized water, DW, leading to weight gain), to neutral (300 mM slightly hypertonic solution, leading to no net weight gain or loss), and aversive (800 mM highly hypertonic solution leading to weight loss). In Experiment 2, a downshift from DW to a 300 mM solution or an upshift from a 300 mM solution to DW led to a gradual adjustment in instrumental behavior. In Experiment 3, extinction was similar after acquisition with access to only DW or with a random mixture of DW and 300 mM. In Experiment 4, a downshift from DW to 225, 212, or 200 mM solutions led again to gradual adjustments. These findings add to a growing body of comparative evidence suggesting that amphibians adjust to incentive shifts on the basis of habit formation and reorganization

Reward devaluation disrupts latent inhibition in fear conditioning

Three experiments explored the link between reward shifts and latent inhibition (LI). Using consummatory procedures, rewards were either downshifted from 32% to 4% sucrose (Experiments 1–2), or upshifted from 4% to 32% sucrose (Experiment 3). In both cases, appropriate unshifted controls were also included. LI was implemented in terms of fear conditioning involving a single tone-shock pairing after extensive tone-only preexposure. Nonpreexposed controls were also included. Experiment 1 demonstrated a typical LI effect (i.e., disruption of fear conditioning after preexposure to the tone) in animals previously exposed only to 4% sucrose. However, the LI effect was eliminated by preexposure to a 32%-to-4% sucrose devaluation. Experiment 2 replicated this effect when the LI protocol was administered immediately after the reward devaluation event. However, LI was restored when preexposure was administered after a 60- min retention interval. Finally, Experiment 3 showed that a reward upshift did not affect LI. These results point to a significant role of negative emotion related to reward devaluation in the enhancement of stimulus processing despite extensive nonreinforced preexposure experience

Influence of Evolutionary Biology in the Early Development of Experimental Psychology In Argentina (1891-1930)

Argentina's first laboratory of experimental psychology was founded in 1891 by the educational psychologist Victor Mercante. Other laboratories were then opened in several universities during the following forty years, giving rise to a considerable development of experimental psychology. The emphasis on experimentation was a common feature of psychology in many other countries, including some Latin American ones. However, Argentine psychology differed from that of other Spanish-speaking countries in the relatively important influence of evolutionary biology on the thinking of several of the most influential psychologists, including Jose Ingenieros, Horacio G. Pinero, Victor Mercante, and Rodolfo Senet, whose ideas and work are described in this paper