Six experiments used rats to study blocking and unblocking of fear learning. An excitatory stimulus (A) blocked fear learning to a neutral stimulus (B). Unblocking of B occurred if the AB compound signaled an increase in unconditioned stimulus (US) intensity or number. Assessments of associative change during blocking showed that more was learned about B than A. Such assessments during unblocki...

Current knowledge on the neuronal substrates of Pavlovian conditioning in animals and man is briefly reviewed. First, work on conditioning in aplysia, that has showed amplified pre-synaptic facilitation as the basic mechanism of associative learning, is summarized. Then, two exemplars of associative learning in vertebrates, fear conditioning in rodents and eyelid conditioning in rabbits, are de...

Words become associated following repeated co-occurrence episodes. This process might be further determined by the semantic characteristics of the words. The present study focused on how semantic and episodic factors interact in incidental formation of word associations. First, we found that human participants associate semantically related words more easily than unrelated words; this advantage...

How do children map number words to the numerical magnitudes they represent? Recent work in adults has shown that two distinct mechanisms-structure mapping and associative mapping-connect number words to nonlinguistic numerical representations (Sullivan & Barner, ). This study investigated the development of number word mappings, and the roles of inference and association in children's estimati...

Associative activation is commonly assumed to rely on associative strength, such that if A is strongly associated with B, B is activated whenever A is activated. We challenged this assumption by examining whether the activation of associations is state dependent. In three experiments, subjects performed a free-association task while the level of a simultaneous load was manipulated in various wa...

Some patients with disorders affecting the hippocampus have relatively intact memory, but the mechanisms underlying this preservation of function are still debated. In particular, it is unclear whether preserved memory is attributable to significant residual function of unaffected hippocampus or to functional brain reorganization. Here, we investigated brain activation during an associative sho...

Associative learning theories offer one account of the way animals and humans assess the relationship between events and adapt their behavior according to resulting expectations. They assume knowledge about event relations is represented in associative networks, which consist of mental representations of cues and outcomes and the associative links that connect them. However, in human causal and...

This paper provides a brief outline of the approaches to modeling human visual attention. Bottom-up and top-down mechanisms are described together with some of the problems that they face. It has been suggested in brain science that memory functions by trading measurement precision for associative power; sensory inputs from the environment are never identical on separate occasions, but the asso...

Two experiments were performed to investigate retention of a discriminative response under conditions of appetitive motivation. In Experiment 1, four groups of rats received 20 training trials in a two-choice position discrimination procedure. Following training, the subjects received 16 test trials .05, I, or 24 h later on a reversal of the original discrimination problem. The results revealed...

Using a previously proposed computational model of human performance on the Implicit Associations Test (IAT), we explore how evaluative conditioning could inform attitude acquisition and formation of automatic associations in memory, and demonstrate the effects of such learning on implicit task performance on the test. This is achieved by augmenting the model with a learning mechanism based on ...