Research On Response-strategy Adjustments In Response Inhibition

In daily life, people always interact with a dynamic cnvironment.For example, driving involves balancing when to accelerate and when to brake. People usually do not try to catch a cactus that is falling off of a desk or touch a hot burner on a stove. Inhibiting the actions to be taken depend on the ability of response inhibition. In the processing of response inhibition, response-strategy adjustments include reactive response-strategy adjustments and proactive response-strategy adjustments. What caused adjustment of strategies in the processing of response inhibition? In the reactive response-strategy adjustments, what caused adjustment of strategies, stop-signal or the result in response for stop-signal? What caused proactive response-strategy adjustments, external cues or increased task demands? This dissertation will research the questions mentioned above.Two studies including six experiments were carried out. The stop-signal paradigm was used in two studies. In experiment3, words were used as experimental materials, and the graphics as materials in other experiments.Four experiments were included in Study1. This study wanted to known that reaction times of no-signal trial behind stop-signal trial were caused by stop-signal or the result in response for stop-signal. Experiment1focus on the differences of reaction time of no-signal trial in different repeat types, and the no-signal trials are behind stop-signal trial. Experiment2and experiment3focuses on the effect of no-signal trial behind signal inhibition and signal response in different numbers of stimulus and response. Experiment4was carried out by ERP, ERN and Pe were used to explore whether the participants regard signal response as errors. To summarize, the findings of the study are as follows:(1) Both signal inhibition and signal response, the reaction times of no-signal trial behind stop-signal trial were longer than total reaction times of no-signal trial. There are no differences between the reaction times of no-signal trial behind signal inhibition and signal response. The reaction times of no-signal trial behind stimulus repetition and response repetition were longer than no-signal trial behind alternative repetition. There are no differences between the reaction times of no-signal trial behind stimulus repetition and response repetition.(2) Reaction times of no-signal trial behind stimulus repetition or response repetition with repeat1are longer than those of no-signal trial behind stimulus repetition or response repetition with repeat3. Reaction times of no-signal trial behind signal response are longer than those of no-signal trial behind signal inhibition. In the condition of signal inhibition, there are differences of reaction times of no-signal trial behind stimulus repetition and response repetition with repeat1and repeat3.(3) Mean amplitudes of ERN behind signal response are far more negative than signal inhibition, and peak value of ERN behind signal response are larger than signal inhibition. Mean amplitudes of Pe behind signal response are far more positive than signal inhibition, and peak value of Pe behind signal response are larger than signal inhibition.Two experiments were included in Study2. This study wanted to known that slowing of no-signal trial result from proactive adjustments of strategies or increased task demands. In experiment5, the slowing of no-signal trial in related condition result from proactive adjustments of strategies or increased task demands. In experiment6, the slowing of no-signal trial in high-percentage result from proactive adjustments of strategies or increased task demands. To summarize, the findings of the study are as follows:In the conditions of Stop signals relevant or irrelevant and different signal frequency, reaction times and correct rate of no-signal trial of Stop signals relevant are higher than those of irrelevant signal, and reaction times and correct rate of no-signal trial of high signal frequency are higher than those of low signal frequency. In the conditions of Stop signals relevant or irrelevant, reaction times of no-signal trial of high difficulty are higher than those of low difficulty, but the correct rates of no-signal trial of high difficulty are lower than those of low difficulty. In the conditions of different frequency, reaction times of no-signal trial of high difficulty are higher than those of low difficulty, but the correct rates of no-signal trial of high difficulty are same with low difficulty.To summarize, following conclusions was made:(1) In the processing of response inhibition, response-strategy adjustments of no-signal trial behind trial with signal can be caused by stop signal. That’s to say; the reaction times of no-signal trial behind signal inhibition and signal response are longer than those of total no-signal trial.(2) In the processing of response inhibition, response-strategy adjustments of no-signal trial behind stimulus repetition and response repetition are executive process of between-trial adjustment but not memory retrieval.(3) In the processing of response inhibition, The participants can regard signal response as errors. That’s to say, Mean amplitudes of ERN behind signal response are far more negative than signal inhibition, and peak value of ERN behind signal response are larger than signal inhibition. Mean amplitudes of Pe behind signal response are far more positive than signal inhibition, and peak value of Pe behind signal response are larger than signal inhibition.(4) In the processing of response inhibition, on the condition of Stop signals relevant or irrelevant and different signal frequency, response-strategy adjustments of no-signal trial are positive adjustment in the same difficult task.(5) In the processing of response inhibition, on the condition of Stop signals relevant or irrelevant and different signal frequency, response-strategy adjustments of no-signal trial result from increased task demands in the different difficult task.