The relative importance of meaiung (semantic context) and spaces between words during reading was investigated. Sub?jects read paragraphs of coherent or incoherent text aloud; some paragraphs were presented normally, others with spaces be?tween words removed. Coherent paragrafrfis were taken from a short story. Incoherent paragraj^ had the same words and punctuation as the coherent paragrajrfis, but the order of these words was randomized, resulting in text devoid of meaning normally provided by context and syntactical structure. As expected, spaced text was read faster and with fewer pronun?ciation errors than unspaced text, and coherent text was read faster and with fewer pronunciation errors than incoherent text, regardless of the presence or absence of spaces between words. Removing spaces slowed reading down less and caused fewer pronunciation errors when the text was meaningful (coherent), than when the text was meaningless (incoherent), so spaces helped more when the text was meaningless than when the text was meaningful. The fact that spaces between words were more important for reading meaningless text than for reading meaningful text suggests that semantics, rather than spaces, are the more important determinants of reading speed and errors.

A unique apparatus recorded eye and head movements of subjects as they tapped or only looked at sequences of 2, 4 or 6 nearby, 3-D targets. Each sequence was repeated 10 times to allow an opportunity for learning. A stereotypical pattern of movements was established after 2-3 repetitions. Subjects almost always looked at each target just before tapping it. Looking-only was more difficult than tapping in that it took more time and, unlike tapping, usually did not benefit from practice. The number of targets in a sequence affected timeA^get in both tasks. Sequence length and practice effects show that memory was involved. The persistent strategy of looking before tapping and the subjects' inability to tap a well-leamed patten with eyes closed, show that visual cues were also important We conclude that motor plarming occurred first at the level of the task and then at the level of specific motor programs. The relative difficulty of the less natural, looking-only task, in which the eyes worked without a meaningful cognitive or motor purpose, suggests that efficient eye movement programming requires a natural task of the kind eye movements evolved to serve.