Hydrocephalus: A neuropsychological and theoretical primer.

Hydrocephalus is a common neurological condition, the hallmark feature of which is an excess in production, or accumulation, of cerebrospinal fluid in the ventricles. Although it is associated with diffuse damage to paraventricular brain areas, patients are broadly typified by a particular pattern of cognitive impairments that include deficits in working memory, attention, and spatial abilities. There have, however, been relatively few neuropsychological accounts of the condition.

The redundancy effect is related to a lack of conditioned inhibition: Evidence from a task in which excitation and inhibition are symmetrical.

Rescorla and Wagner's model of learning describes excitation and inhibition as symmetrical opposites. However, tasks used in human causal learning experiments, such as the allergist task, generally involve learning about cues leading to the presence or absence of the outcome, which may not reflect this assumption. This is important when considering learning effects which provide a challenge to this model, such as the redundancy effect.

Uncertainty and blocking in human causal learning.

The blocking phenomenon is one of the most enduring issues in the study of learning. Numerous explanations have been proposed, which fall into two main categories. An associative analysis states that, following A+/AX+ training, Cue A prevents an associative link from forming between X and the outcome.

The redundancy effect in human causal learning: No evidence for changes in selective attention.

Several recent papers have reported a difference in associative learning for two kinds of redundant cues, such that a blocked cue (e.g., X in A+ AX+) apparently forms a stronger association with the outcome than an uncorrelated cue (e.