Methods used in reading research

Question 1

What do we see when reading?

Answer 1

As visual acuity drops off rapidly from the point of fixation, only 4-5 letters are seen with 100% accuracy - perceptual span is 4 characters to the left, 15 characters to the right of fixation.

Question 2

How is eye tracking achieved?

Answer 2

A low-level infrared light is picked up by a camera, determining where the pupil is.

Question 3

What has eye tracking shown about fixations and saccades when reading English?

Answer 3

Eyes move from left to right 85% of the time and right to left (new line/going back) 15% of the time.

Question 4

How long are fixations in English?

Answer 4

60-500ms, average 250ms.

Question 5

Describe saccades in English.

Answer 5

They vary between one character and a whole sentence, with an average of 6-9 characters.

Question 6

What are the early measures of reading time?

Answer 6

First fixation duration and first-pass reading time (for the word of interest).

Question 7

What are the later measures of reading time?

Answer 7

Regression path and total reading time.

Question 8

What can eye-tracking experimental designs do other than simply monitoring eye position?

Answer 8

They can be used to create gaze-contingent paradigms.

Question 9

What are gaze-contingent paradigms?

Answer 9

Information is fed back to the computer, which changes the display - for example once an invisible boundary is passed a word can be changed.

Question 10

What can gaze-contingent paradigms be used for?

Answer 10

Measuring preview effects - if the (non-)word ‘evh’ is initially presented, then changed to ‘sat’, compared to the sentence with the correct preview it takes 40ms longer to read - this is the preview benefit; the word is already processed to some extent before it’s looked at.

Question 11

What are the advantages of eye tracking as an experimental method?

Answer 11

It measures naturalistic behaviour, is non-intrusive, provides moment-by-moment indication of ease (or difficulty) of text comprehension, and allows the use of gaze-contingent paradigms.

Question 12

What are the disadvantages of eye tracking as an experimental method?

Answer 12

It is labour intensive for the experimenter, there are training requirements, and it’s expensive.

Question 13

When using ERPs, what can cause EEG artifacts?

Answer 13

Blinks, muscle movements and eye movements.

Question 14

How can the problem of EEG artifacts be solved?

Answer 14

By asking participants not to blink/move, presenting stimuli word-by-word, and removing from the data with algorithms. Participants should also read several hundred sentences to even out noise.

Question 15

What are ERP components?

Answer 15

Predictable and identifiable waveforms which co-vary in response to experimental manipulations.

Question 16

What are two language-related ERP components?

Answer 16

The N400 and P600.

Question 17

What can ERP components be described in terms of?

Answer 17

Latency (after first seeing word), polarity (negative plotted upwards on graph, positive plotted downwards), and scalp distribution.

Question 18

What is the N400 argued to reflect difficulty with?

Answer 18

Integrating words into context (sentence and discourse incongruity) and semantic retrieval (affected by word frequency and repetition).

Question 19

What evidence is there that the N400 is related to integration of words into context?

Answer 19

1. Sentence incongruity: Kutas & Hillyard (1980) found that incongruous sentences cause ERP to shoot up (N400) relative to congruous sentences.
2. Discourse incongruity: Van Berkum et al. (1999) found that a sentence anomaly causes ERP to shoot up (N400) relative to a coherent sentence.

Question 20

What evidence is there that the N400 is related to semantic retrieval?

Answer 20

N400 for less frequent words and small N400 for unrepeated words.

Question 21

What is the P600?

Answer 21

A syntax-related ERP component.

Question 22

In what cases is the P600 observed?

Answer 22

• Subject verb agreement (Hagoort, Brown & Groothusen, 1993) - grammatical error
- The spoilt child throws/throw the toy on the ground
• Syntactic ‘garden path’ sentences (Osterhout, Holcomb & Swinney, 1994) - complex grammatical structure
- The professor saw (that) the student would succeed

Question 23

What are the advantages of ERPs?

Answer 23

They’re a non-invasive technique that measures neural activity in real time. Measures are ‘time-locked’ to a critical event, and different components can reflect different underlying cognitive processes, unlike eye-tracking which only shows difficulty.

Question 24

What are the disadvantages of ERPs?

Answer 24

• Unnatural word-by-word stimulus presentation
• Hard to tell ‘where’ in the brain processes occur
• EEG artifacts can be difficult to remove
• Labour intensive/expensive/training requirements