The channels of memory loss

Forgetfulness is an integral part of memory. In the context of work on normal ageing, the group Ageing and Memory made an fMRI study (1) of the mechanisms of forgetfulness through a task called “directed forgetting” – the participants had to learn lists of words after which they were required to “retain” or, conversely, to “forget” words.

What did the neuroimaging reveal? That directed (and consequently, voluntary) forgetting depends essentially on attentional networks. “In other words, it is underpinned by a reallocation of the attention of the subject and not, as might have been previously believed, by a mechanism of inhibition”, points out Eric Salmon. Everything happens as if the subject, rather than expending energy by recalling a memory from his mind, loses interest by polarizing his attention on another word - for example the next word to be remembered.

(1) Bastin C. et al., The neural substrates of memory suppression: an fMRI exploration of directed forgetting, PLoS One, 7(1), e29905, 2012.