Artificial optoelectronic synapses, as a typical neuromorphic device, have garnered significant attention due to their concurrent capabilities in processing visual perception and memory. In this study, we propose an artificial optoelectronic synapse with a dual-terminal metal-semiconductor-metal (Au/TiO2/Cr/Au) structure. By modulating the concentration of oxygen vacancy defects in TiO2, the device exhibits a significant persistent photoconductivity (PPC) effect. The devices successfully simulated the synaptic behaviors, including paired-pulse facilitation (PPF), short-term plasticity (STP), long-term plasticity (LTP), and the learning-forgetting process. In addition, the device array has the capability to recognize optical signals and exhibits an obvious response gradient under different optical powers. This demonstrates its ability to adaptively detect optical signals and simulate human visual memory.