EFFECTS OF COMPETING LEXICAL DISTRACTERS IN A VISUAL SEARCH TASK

Abstract

ABSTRACTStudies have shown that distracters that are relevant to a target can negatively affect visual search performance. Recent studies have looked at performance when targets are embedded within a distracter. Various factors have been explored such as automaticity, spatial location and timing. This study asked, If distracters affected a different dimension would that produce a detriment to visual search performance? Would competition for attention occur if distracters were on an irrelevant dimension such as lexicality? The results of this study suggest that lexicality, as demonstrated by word frequency, is a disruptive distracter dimension. This study also showed that two distracters of different word frequencies can serve to disrupt attentional capture.Keywords: Lexical Distracter, Attention Capture, Visual Search1. INTRODUCTIONThis experiment expanded on a previous examination of word frequency effects in visual search tasks (Grabbe, 2014) by allowing a simultaneous comparison of distracter words with embedded targets and distracter words without embedded targets within the same trial. This facilitated a greater examination of comparative word frequency effects as distracters (example, the target could be embedded within a low frequency word in a letter string which also contains a high frequency word).This study will answer the question: If there was a proximity effect that disrupted the effect of lexicality, would the distracter influence of lexicality still be disruptive when proximity (embeddedness) is also a factor. This will allow a thorough examination of holistic effects of distracter words on the target search task. Grabbe showed an advantage for targets embedded within a word and the reverse word frequency effect. This study will examine the proximity dimension of distracters by utilizing targets embedded within a word and have an additional, nonembedded distracter word.Hypothesis 1A holistic bias will lead to longer reaction time for targets embedded within high frequency words.Hypothesis 2High frequency distracter words will cause a greater distraction than low frequency words. Therefore longer reaction times will be observed for high frequency word distracters.2. MATERIALS AND METHODS2.1. ParticipantsNineteen participants were recruited from psychology courses at the State University of New York, Plattsburgh. The age range was from 21 to 51 years of age. All participants were screened for normal or corrected-to-normal visions. Informed consent was obtained from all participants.2.2. ProcedureParticipants completed a visual search task in which they searched for a target letter within a letter string. The target letter was presented before each trial. In the experiment all targets were embedded within a word or nonword in a letter string. Each letter string also had a second word which served as a distracter and did not have an embedded target.For the purpose of clarity the distracter in which a target is embedded (which can be a word or nonword) will be referred to as the first distracter and the distracter that does not contain an embedded target (which is always a word) is referred to as the second distracter. Example, the target is the letter L and the letter string is XRATOHOLEYSDT. In that letter string the target appears is embedded in the first distracter (the word hole) while the word rat serves as the second distracter (Fig. 1).Participants completed 10 practice trials before completing 600 experiment trials. Target present trials were composed of three word frequency categories. Each word frequency category for first distracters contained 160 trials of nonreplaced words along with second distracters that were spread equally across word frequency category. Words from word frequency database of Brysbaert and New (2009) were used in this experiment in the target absent condition, no letter string contained a legal, English word. …