Clinical research has linked post-traumatic stress disorder (PTSD) with deficits in fear extinction. However, it is not clear whether these deficits result from stress-related changes in the acquisition or retention of extinction or in the regulation of extinction memories by context, for example. In this study, we used the single prolonged stress…

The understanding of how the reinforcement is represented in the central nervous system during memory formation is a current issue in neurobiology. Several studies in insects provide evidence of the instructive role of biogenic amines during the learning and memory process. In insects it was widely accepted that dopamine (DA) mediates aversive…

Same-different categorization is a fundamental feat of human cognition. Although birds and nonhuman primates readily learn same-different discriminations and successfully transfer them to novel stimuli, no such demonstration exists for rats. Using a spatial discrimination learning task, we show that rats can both learn to discriminate arrays of…

The performance of developing zebrafish in both classical and operant conditioning assays was tested with a particular focus on the emergence of these learning behaviors during development. Strategically positioned visual cues paired with electroshocks were used in two fully automated assays to investigate both learning paradigms. These allow the…

We investigated changes in bias (preference for one response alternative) in signal detection when relative reinforcer frequency for correct responses varied across sessions. In Experiment 1, 4 rats responded in a two-stimulus, two-response identification procedure employing temporal stimuli (short vs. long houselight presentations). Relative…

In a temporal double bisection task, animals learn two discriminations. In the presence of Red and Green keys, responses to Red are reinforced after 1-s samples and responses to Green are reinforced after 4-s samples; in the presence of Blue and Yellow keys, responses to Blue are reinforced after 4-s samples and responses to Yellow are reinforced…

Syntax is widely considered the feature that most decisively sets human language apart from other natural communication systems. Animal vocalisations are generally considered to be holistic with few examples of utterances meaning something other than the sum of their parts. Previously, we have shown that male putty-nosed monkeys produce call…

A Grey parrot ("Psittacus erithacus") had previously been taught to use English count words ("one" through "sih" [six]) to label sets of one to six individual items (Pepperberg, 1994). He had also been taught to use the same count words to label the Arabic numerals 1 through 6. Without training, he inferred the relationship between the Arabic…

In this paper we discuss some literature relating to episodic memory, future episodic thinking and mental time travel in humans and non-human animals. We discuss the concept of mental time travel and argue that the concept relies on subjective phenomena such as consciousness and on this basis is not useful when studying episodic memory and future…

In this forum I expand on the ideas I initially presented in "Extending the purposes of science education: addressing violence within socio-economic disadvantaged communities" by responding to the comments provided by Matthew Weinstein, Francis Broadway and Sheri Leafgren. Focusing on their notion of utopias and superheroes, I ask us to reconsider…

Philosophers use hypothetical duplication scenarios to explore intuitions about personal identity. Here we examined 5- to 6-year-olds' intuitions about the physical properties and memories of a live hamster that is apparently duplicated by a machine. In Study 1, children thought that more of the original's physical properties than episodic…

By growth in size and complexity (i.e., changing from more probable to less probable states), plants and animals appear to defy the second law of thermodynamics. The usual explanation describes the input of nutrient and sunlight energy into open thermodynamic systems. However, energy input alone does not address the ability to organize and create…

This activity uses inquiry to investigate how large changes in shape can evolve from small changes in the timing of development. Students measure skull shape in fetal, infant, juvenile, and adult chimpanzees and compare them to adult skulls of "Homo sapiens," "Homo erectus," and "Australopithecus afarensis." They conclude by re-interpreting their…

Teachers may be posed with such questions as, "If we evolved from chimps, why are there still chimps?" We provide teachers with answers to this and related questions in the context of the latest genetic, fossil, and behavioral evidence. We also provide references they can use to further students' understanding of human evolution and evolution in…

In this article, the author describes how placing a plastic, gazebo-style bird feeder outside the classroom windows one cold autumn morning had been a catalyst for capturing and inspiring the children's imaginations. This empowered them to explore self-directed activities that resulted in meaningful, collaborative learning for most of the school…