粘菌変形体という巨大なアメーバ様生物が、周期的環境変動下で
どのような振舞いを見せるかを調べていたら、周期性の記憶や想起と
おぼしき現象を発見した。詳細は以下を参照されたし。
これらの結果、ならびにそこで提案した振動子集団モデルを紹介する。
物性物理の分野との関連がないか議論したい。
Single-celled organisms might be cleverer than previously thought. Anticipating and recalling events are higher functions performed by the brains of higher animals; their evolutionary origins and the way they self-organize, however, remain open questions. Here we show that an amoeboid organism can anticipate the timing of periodic events. The plasmodium of the true slime mold {\it Physarum polycephalum} moves rapidly under favourable conditions, but stops moving when transferred to less-favourable conditions. Plasmodia exposed to unfavourable (low-temperature and low-humidity) conditions, presented in three consecutive pulses at constant intervals, reduced their locomotive speed in response to each episode. When subsequently subjected to favourable conditions, the plasmodia spontaneously reduced their locomotive speed at the time point when the next unfavourable episode would have occurred. This implied anticipation of impending environmental change. After this behaviour had been evoked several times, the locomotion of the plasmodia returned to normal; however, the anticipatory response could subsequently be induced by a single unfavourable pulse, implying recall of the memorized periodicity. We explored the mechanisms underlying these behaviours from a dynamical systems perspective. Our results hint at the cellular origins of primitive intelligence and imply that simple dynamics might be sufficient to explain its emergence.