The idea of two-process theories and the Stroop effect are assessed in this experiment. The intention is to look for a predicted pattern between the response times of two separate conditions; one using a list of words that are colour related, such as “lemon” and another list of words which are all neutral such as “chair” . The participants were asked to name the colour of the ink which each word was printed in. The prediction is that the response times for the Stroop condition (colour related words) will be higher than those for the control condition (neutral words). (100 words)
The Stroop effect is what is being focused on in this project. Stroop (1935) (as cited in Edgar 2007) did research on the relationship between automatic and controlled processes, suggesting it is harder to name the colour of the ink a word is written in if the word is colour related such as blue or red, than if the word was a neutral word such as chair or table. The reason for this can be explained in dual-task studies, such as the one conducted by Posner and Boies (1971) (as cited in Edgar 2007). They asked participants to do two things at once, one visual and one auditory. Posner and Boise found that if the auditory task was presented at the same time as the visual task, the response times were slower than if it was presented shortly after the visual task. This suggests that the brain has a limited pool of resources and can process incoming stimuli more efficiently when not presented together. Interestingly, McLeod (1977) (as cited in Edgar 2007) adjusted Posner and Boise’s study by requiring an audible ‘bip’ from the participant as opposed to a button press as in the original study, and he found there was no difference in response times between the conditions, even when the tasks were presented together. This suggests that there is a separate pool of resources available for audible tasks and for manual tasks. A study by MacDonald et al (2000) (as cited in Edgar 2007), introduced functional magnetic resonance imaging (fMRI) to analyse the activity in the dorsolateral prefrontal cortex (DLPFC) and the anterior cingulate cortex (ACC) whilst the Stroop word task we are conducting now, was being performed. Macdonald hypothesized that the DLPFC is responsible for allocating attention to the task, whilst ACC is responsible for identifying any errors made during the task. He was to test this hypothesis by modifying the Stroop test to include 2 tasks, naming the ink colour as in the original task, and also to simply read the word, a more automatic task, and analysing the responses in the DLPFC and the ACC. His findings showed that the DLPFC was active during the original task of naming the ink colour and was inactive when reading the word, thus confirming that the DLPFC is not active when performing an automatic response task not requiring special attention. He also found that the ACC was more active during the original task, because it is actively looking for errors in the responses whereas during the automatic task of reading the word is was less active because there were less errors made and the ACC wasn’t needed.
This research ties in with our current experiment. We are looking to either confirm or reject the Null hypothesis – ‘there will be no difference in response times from condition 1 to condition 2’. Our research hypothesis is: ‘the response times from condition 1, the Stroop condition, will be lower (slower) than the response times from condition 2, the neutral words’.
This study has a within-participants design and is to evaluate the effect of dual tasking on the processing of information as we receive it. The independent variable being manipulated is the list of words that...