Two-way active avoidance task

Winneke et al (1982b) carried out an interesting study which demonstrates how relevant the nature of the learning task is. In their study rats were dosed pre- and post-natally with lead. Animals were tested on a two-way active avoidance task, and later on a visual discrimination task. In the discrimination task the performance of lead-dosed animals was inferior to the controls. In the avoidance task the performance of animals improved significantly in a dose-related fashion, with increasing lead level. 

The authors suggest that increased behavioural reactivity may be the explanation for these differential effects. An alternative explanation is that the improvement on the two-way active avoidance task is due to damage to the hippocampus, or related structures, as this is known to improve performance on this task. This is thought to be because of deficits in spatial ability, so that the animal loses the sense of place, and does not remember, and therefore does not fear, the previously dangerous place. 

Another study has also reported an improvement in two-way active avoidance tasks in lead-dosed animals, but this must be balanced against two studies where the performance of lead-dosed animals was worse, and another three studies reviewed by Cavanagh et al (1984) found no differences at all. 

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