eyetrackR
Description
eyetrackR is an R package providing a set of utility functions for the analysis of eyetracker data. Currently it is geared towards, but not limited to, eye movements during reading. Starting from the raw time series of x and y samples, the package allows automated classification into saccades and fixations, with adjustable saccade detection parameters. Saccade detection results in a fixation sequence. From this sequence, given additional input about the reading material, aggregate measures such as gaze durations (first-path dwell time on a word) or skipping probabilities are computed. The data are shaped into a format that facilitates analyses using a distributed-processing approach, i.e., taking into account influences of the neighboring words (or fixations) on the current fixation duration. Sample analyses demonstrate how these measures can be analyzed as a function of word and reader parameters, using linear mixed effects models.
The package also contains a number of utility functions, such as parseq, firstpass, plotsacc, and computeReadingMeasures.
Installation
Download and save package to a directory, then from within R either install as a local source package using the package manager GUI or setwd() to that directory and type
install.packages("eyetrackR_0.16.tar.gz", repos = NULL, type="source")
Procedure
1. data preprocessing
(edf to ascii conversion, .dat, .msg, and .msg2 file creation and cleanup)
- preprocess (requires installed edf2asc utility by SR research)
(case management)
- xallsac_l3 (demo)
2. message file parser
- parse_msg_file (demo)
- parms1 # usage: data(parms1); contains detection parameters
- readSubjects
3. (micro-)saccade detection
- vecvel
- microsacc
- binsacc
- saccpar
4. analysis of fixation sequences
(currently mainly contains demos)
- xSetup1_l3 (demo)
- computeReadingMeasures
- xIndex_fix_l3_logical (demo)
- xSetup2_l3 (demo)
5. definition of aggregate measures
(currently only contains demos)
- xSetup2.2_dvmat_l3 (demo)
6. sample statistical analysis
Author(s)
Jochen Laubrock with Reinhold Kliegl, Ralf Engbert, Sarah Risse, Daniel Schad, Michael Dambacher
Maintainer: Jochen Laubrock
References
Laubrock & Kliegl (in preparation). eyetrackR: an R package for the analysis of eye movement data.
Engbert, R., & Mergenthaler, K. (2006) Microsaccades are triggered by low retinal image slip. Proceedings of the National Academy of Sciences of the United States of America, 103, 7192–7197.
Examples
#############################################################
## (micro-)saccade detection
#############################################################
data(trial4)
# names(trial4) <- c("t", "xl", "yl", "pl", "xr", "yr", "pr")
SAMPLING <- 500
VFAC <- 5
MINDUR <- 3
vl <- vecvel(trial4[,c("xl", "yl")], SAMPLING, 2)
sacl <- microsacc(trial4[,c("xl", "yl")], vl, VFAC, MINDUR)
vr <- vecvel(trial4[,c("xr", "yr")], SAMPLING, 2)
sacr <- microsacc(trial4[,c("xr", "yr")], vr, VFAC, MINDUR)
sacb <- binsacc(sacl$sac, sacr$sac)
sacb2 <- saccpar(sacb$sac)
#############################################################
## sentence corpus
#############################################################
data(PSC2.DWDS)
example(PSC2.DWDS)
#############################################################
## reading measures
#############################################################
data(a)
a2 <- computeReadingMeasures(a)
summary(a2)
 eyetrackR_0.16.tar.gz | [eyetrackR: R package supporting the analysis of eye movement data] | [ ] | 1897 Kb | 26/06/2012 21:07 |
 Eyetracking_Datenanalyse_Laubrock.pdf | [(in German): Presentation describing eye movement data analysis, with some eyetrackR examples] | [2] | 10389 Kb | 15/09/2010 19:04 |
| Aufgaben | [(in German): exercises using eyetrackR] | [3] | 3644 Kb | 15/09/2010 19:05 |
