Have you noticed, a similar effect can occur when one is in the speaking role of a conversation: looking directly at the conversation partner for too long a time may cause the processing of the visual input to override one's train of thought, limiting speaking ability.
Definitely, and ironically it is worse when the other person is a really, really attentive listener and the signals are in cadence but inherently out of phase. Faster conch passing helps that. In a group speaking situation, scanning past "that" person can be effective.
