I. introduction
--> eye tracking is important because it gives indicators towards linguistic complexity
II. basic characteristics of eye movement during reading
A. saccades
def: the jumps forward in text your eyes make
time: 20 - 40 ms
B. fixations
def: when your eyes are stationary
time: 50 - 500 ms
1) the only time when important information is extracted
2) quantity directly proportional to the length of a given word
3) sometimes, there will be no fixations on small words, just a saccade over
C. regressions
def: when your eyes backtrack
time: depends on the text
1) usually used for clarification, detects ambiguities easily
D. anatomy of the eye
1) text regions during a fixation
a) foveal
--> 1 degree on either side of the fixation point
b) parafoveal
--> 5 degrees on either side of the fixation point
--> not much can be learned from this area
c) peripheral
--> you can pretty much only tell where a line ends
E. the "perceptual region"
1) in English, this is usually 15 or 16 letters to right of the fixation point, yet only 3 to 4 to the left because English is read left to right
2) in Hebrew, this is the opposite because Hebrew is read right to left
3) in Mandarin, this is considerably smaller (3 to 4 on each side) because each character contains more information per unit than letters do in other languages
*** not simply dependent on how much you can see, actually has to do with how you process the text you're seeing
4) "looking ahead"
--> readers will tend to "look ahead" at the word to the right of the one being fixated on, but you can usually only tell a couple of letters and maybe a general sound
--> the word to the right will only become clear morphologically and semantically when it is fixated on
5) skipping words
--> short words are usually skipped because they're predictable and frequent
6) moving between words
--> saccades are shorter when there's less text coming up in the perceptual region
--> the spaces between words are extremely important as well, with saccades varying accordingly
--> fixations are usually in the first half of the word and when they are, they're usually short
7) when to move the eyes
--> depends most largely on text comprehension and reveals higher-level conceptual comprehension
8) fixation duration
a) for a single target word
--> first fixation duration
--> single fixation duration (for single fixation words)
--> gaze duration (for multiple fixation words)
--> regression path duration (including rereadings)
--> second pass time (only rereadings)
b) for a target section of text
--> first pass time (gaze duration for a section of text)
*** this is all to help us understand how the brain comprehends text
9) eye-mind span
a) the latency between visual and mental processing
b) if the link between the two is tight, we know that visual and mental processing are closely related, and that the amount of time someone spends looking at a word will determine how long they take to process it
III. effects of lexical processing on eye movements
A. intrinsic lexical factors (frequency, morphology, and lexical ambiguity)
1) of course, infrequent words will be looked at for longer
2) but if it's repeated throughout the text, the fixation time nosedives
3) word frequency vs. word familiarity (objective vs. subjective)
a) frequency: how often a word appears in a corpus
b) familiarity: self-explanatory, how familiar the person is with the word
--> independent of frequency
4) morphological structure
a) the first morpheme in a two-morpheme word highly influences the fixation duration
b) suggests that the brain separates a word into its morphemes, even if it's transparent or opaque
--> transparent: the meaning of the word comes from its parts
--> opaque: the meaning of the word doesn't come from its parts (headless)
5) meaning ambiguity
a) if a word has two equally likely meanings, it takes a lot longer to read
b) it a word has one dominant meaning, the reading time is not generally slowed at all
c) if the word's meaning is not the dominant one in context, you can expect a lot of regression and fixation
d) the subordinate bias effect
--> if the words before an ambiguous word reveal it to be nondominant, reading time on the previously ambiguous word goes up
--> will not hold if the two possible meanings are different parts of speech or different syntactic categories, like rose (past tense of rise or the flower?), because only one will make the sentence syntactically correct
e) but, if the two possible meanings are different parts of speech and they both make sense (I know that the desert trains...), the reader won't slow down at the word itself because it'll make sense either way... they'll slow down later in the sentence
f) also, when two different words have the same spelling, like read (the past tense of read, or the verb itself?), or when you encounter homophones (blue and blew)
B. relational lexical factors (how those affect eye movement)
1) as is obvious, as things get more predictable, they get quicker to read
2) semantic priming
def: using the context of the previous