The Development Of Prospective Memory Based On Task-characteristics

Prospective memory refers to an implementation of planed event during appropriate time in future. During recent years, the basic operation of the laboratory studies is that the event-based prospective memory task embedding into ongoing task. So the impact of "dual-task" characteristics has been concerned by researchers. However, some tasks characteristics affected prospective memory performance was still controversial, and fewer studies referred to how the task characteristic affects allocation of attention resources and strategy selection. This study focused on the influence mechanism of task characteristics, explored the impact of task characteristics on strategy selection and allocation of attention resources in prospective memory processing.The objects are undergraduates and elderly participated in, and we used classical "dual-task" paradigm. It contained seven experiments.The first study investigated the development of prospective memory task characteristics explored the effects of prospective memory task characteristics on the processing mechanisms and aging effect, In experiment 1, we informed undergraduates the importance of prospective memory tasks through the guidance and examined the differences of prospective memory performance, as well as selection of strategy under the conditions of given different weights of prospective memory task. In experiment 2, we controlled the clarity of prospective memory task. One group was informed the specific tasks, and another was informed general tasks. With the purpose of the association of targets and behavior which participants formed during the encoding phase influenced strategy when prospective memory was retrieved? In experiment 3, we confirmed importance and clarity of prospective memory task have aging effect. The results showed that the importance and clarity of prospective memory task affected prospective memory performances. Emphasizing the importance of prospective memory task can improve prospective memory performance. The prospective memory performance was better when the prospective memory task was clarity. Participants allocated attentional resources and selected different processing strategies initiatively according to the characteristics of the task. The aging effect was significant when prospective memory tasks were unimportance and ambiguity. But the negative affects of aging effect can be alleviated when prospective memory tasks were importance and clarity.The second study investigated the development of ongoing task characteristics. In experiment 4, we manipulated the difficulty and observed the effects of the prospective memory performances when attentional resources of ongoing task were varied. In experiment 5, we designed two kinds of processing tasks, semantic and perceptual. Prospective memory tasks and ongoing tasks were composed four kinds of task contexts. They are semantic-semantic task, perceptual-perceptual task, semantic-perceptual task and perceptual-semantic task. In experiment 6, we selected elderly to confirm aging effect of ongoing tasks characteristics. The purpose is examined the allocation of prospective memory attention resources and strategy selection under different task contexts. The results showed that:Both the difficulty of prospective memory task and consistency of tasks situational affected prospective memory performance. When task contexts were consistent, the prospective memory performance was better. When attention resources of the ongoing task increased, the attention resources of the prospective memory task decreased oppositely, and so the prospective memory performance was reduced. The aging effect was significant when tasks situation consistency and ongoing tasks were highly difficulty. But the negative affects were low when prospective memory tasks were importance and clarity or tasks situation were consistent and difficulty of ongoing tasks.The third study is eye movement research of prospective memory processing mechanisms. We chose figures as stimulus materials, and used Eye-movement recorder to record the participants'eye movements to search for the prospective memory target cues in the conditions of multi-element display. The purpose is to examine the effect of the difficulty tasks of prospective memory from time course. We examined the processing mechanisms of prospective memory using physiological index in this study.The results showed that:When prospective memory targets and ongoing task were presented at the same time, the prospective memory performance was susceptibly interfered, especially when the difficulty of prospective memory task was increased. The unsuccessful of the prospective memory was due to the lack of the preparatory processing for the prospective memory targets.This study supports the theory of prospective memory in bi-process theory.