The influence of external stimulation in missing knowledge retrieval.

We investigated the effects of sensory reduction on the retrieval of information during tip-of-the-tongue (TOT) experiences. As conscious access results from severe competition in which external stimuli often have priority, we hypothesised that reducing external stimulation would allow individuals greater access to weakly activated inner knowledge. In Study 1, when participants experienced a TOT while answering a general knowledge question, they were given additional time to find the solution in a restricted (eyes closed + silence) or a non-restricted (eyes open + ambient noise) external stimulation environment. Results indicated that knowledge was more often retrieved when external stimulation was restricted than when not restricted. This result was replicated in a second study. Using an independent manipulation of the level of auditory and visual stimulation, Study 2 also indicated that the presence of visual stimulation was more disruptive for TOT resolution than the presence of auditory stimulation. Overall, the findings suggest that sensory restriction (especially of visual stimuli) facilitates the retrieval of weakly accessible knowledge through a greater processing of inner stimuli.