School of Psychology Debriefing Sheet Project Title: EEG and Word Processing Researcher: Elisa Pye Thank you for participating in this study on word reading. The purpose of this leaflet is to summarise this experiment and to tell you a little more about the cognitive research in which I am interested. This project aimed to investigate the contribution of semantic memory to the process of single word reading. Semantic memory is a form of memory that stores general knowledge about everyday word and objects. For example: knowledge that a dog is a four-legged domesticated animal (NOT memories about a specific dog you owned or the memory of seeing a woman walking a dog this morning). This research is concerned with how this general knowledge about the world aids in the translation of printed letters, which make-up words, to the correct pronunciation of that word. In short, how do we form the correct pronunciation of words and is semantic memory involved? In this experiment, you were asked to read words silently to yourself and press a button as you did so. This is a covert naming task, as, though you were naming the item, you were not doing this aloud. While you were doing this we recorded the electrical signals at your scalp that were produced in your brain in response to the words on the screen. It was important that you not say the words aloud as the muscle activity would have disrupted the recording. The words you read were manipulated in terms of difficulty; although it is very unlikely you would be aware of this. You were given 2 levels of word difficulty. For example: harder words such as “sieve” and easier words such as “goat”. We would expect, based on the literature, for the different word types to illicit different reaction times. We will, therefore, be using your button press reaction times as a way to check that you were reading the word to yourself, as the amount of time it took you to press the button should differ between the two word difficulty types. In addition to word difficulty, we also manipulated the words on a semantic variable. For example, in one group of words the semantic variable we manipulated was imagability, which is the ability of a word to garner a fairly specific image from any of the senses, not just a mental picture. There were 4 word types in total: harder words that are high in the semantic variable, harder words that are low in the semantic variable, easier words that are high in the semantic variable, and easier words that are low in the semantic variable. The current literature debates whether word reading (when a word is translated in the brain from print to sound) needs semantic information for the brain to determine the correct pronunciation of a word, and this is what I am investigating. If there are differences in the EEG recording (on an averaged group level) within word difficulty level, but between the semantic variable levels (in other words, comparing harder words that are high in imagability and easier words that are low in imagability), I can assume that this occurred because the brain is using semantics to help read a word correctly. Because my words are matched very closely on other variables, I can infer that any differences are occurring because of semantic processing in word reading. For example, I might see that the harder words that are high in a semantic variable produce a different pattern of brain response than harder words that are low in a semantic variable. Perhaps the easy words will not show a difference in brain response pattern between the high and low semantic conditions because these words are efficiently processed. Perhaps they are read so efficiently that the brain does not receive the help from semantic memory in time to help with the correct pronunciation. From the results, I will be able to draw some conclusions about the processes that are used when words read. In particular, I should be able to draw some inferences about whether semantic memory is involved in this process. This work will help contribute to theoretical models of word reading. Once again, thank you for participating, and would like to reassure you that all the data is anonymous. I hope that you enjoyed taking part in the experiment. Do contact me if you want to find out anything else. Thanks again, Elisa Pye PhD candidate, Psychology Contact for further information: If you have any questions please contact Elisa Pye on 020 8223 4595 or email me at firstname.lastname@example.org.