1. Introduction
Does word orientation affect the time that it
takes to process a word? It is important to
answer this question so the processing of
words, in a temporal sense, can be known.
he hypothesis was that non-upright words
would have a larger ERP amplitude for the
N1 response over the posterior electrodes.
This was based on what is observed in the
face processing literature; inverted faces
show a larger N1 response compared to
upright faces. Such a finding would suggest
that, like faces, words are processed
holistically, as a whole object, and not letter
by letter.
Methods
EEG of five participants were obtained using
a 64-channel EEG cap. The trials were
presented in e-prime. Each trial consisted of
a fixation cross followed by the stimulus,
followed by a response screen that recorded
the responses for accuracy. All data were
filtered from .1 to 100 hertz and
preprocessed in eeglab, a matlab toolbox.
Example of an EEG cap Examples of stimuli
References
Sussman, Reddigari, Newman. (under review). Does reading
spatially transformed text disrupt orthographic processing?
Acknowledgements
Indiana CTSI/IU Research Office
Department of Psychological and Brain Sciences
Office of Diversity, Equity, and Multicultural Affairs
College of Arts and Sciences
Possible Problems
The data may have been impeded by having
only five subjects. It will be necessary to
collect more data. Also, the fourth subject
had conditioner in their hair, which
increased the impedances of the electrodes.
However, this was compensated for by
wetting the electrode more often. Finally,
when saving data, only four steps of the first
subject’s were saved when their data were
preprocessed, while nine to thirteen steps
of the other subjects were saved.
Results
The following is a sample electrode, E33, showing
the group average (n=5) of the results of each word
condition. There is a P1 followed by an N180 in
each condition.
Below are all electrodes.
Below is the accuracy of each subject.
Discussion
The results from five participants showed an
N1 for all conditions in the posterior
electrodes. Additionally, like with faces, the
inverted words showed a larger response
than both rotated and upright words.
Additionally, the rotated words revealed a
larger P1 and inverted words showed an
increased, slow negativity late in processing.
This could mean that it takes longer to
process the inverted words, which support
the hypothesis.
Does word orientation affect word processing: an ERP study
Marcus Byrd, Isaiah Innis, and Sharlene Newman
Indiana University, Department of Psychological and Brain Sciences, Bloomington, IN, USA