metafor (version 1.9-8)

dat.bourassa1996: Studies on the Association between Handedness and Eye-Dominance

Description

Results from 47 studies on the association between handedness and eye-dominance.

Usage

dat.bourassa1996

Format

The data frame contains the following columns:

study	numeric
study number	sample
numeric	sample number
author	character
(first) author	year
numeric	publication year
selection	character
selection of subjects on the basis of eyedness or handedness	investigator
character	investigator (psychologist, educationalist, or other)
hand_assess	character
method to assess handedness (questionnaire or performance based)	eye_assess
character	method to assess eyedness (see below for classification)
mage	numeric
mean age of sample	lh.le
numeric	number of left-handed left-eyed individuals
lh.re	numeric
number of left-handed right-eyed individuals	rh.le
numeric	number of right-handed left-eyed individuals
rh.re	numeric
number of right-handed right-eyed individuals	study

Source

Bourassa, D. C., McManus, I. C., & Bryden, M. P. (1996). Handedness and eye-dominance: A meta-analysis of their relationship. Laterality, 1, 5--34.

Details

The 47 studies included in this meta-analysis examined the association between handedness and eye-dominance (ocular dominance or eyedness). Results are given in terms of $2x2$ tables, indicating the number of left-handed left-eyed, left-handed right-eyed, right-handed left-eyed, and right-handed right-eyed individuals. Note that some studies included multiple (independent) samples, so that the meta-analysis included 54 samples in total. Also, for some studies, the combined data of the males and females are further broken down into the two subgroups.

In some studies, there was indication that the selection of subjects was not random with respect to handedness and/or eyedness. While this should not influence the size of the association as measured with the odds ratio, this invalidates those studies for assessing the overall percentage of left-eyed and left-handed individuals.

Handedness was assessed in the individual studies either based on a questionnaire or inventory or based on task performance. Eyedness was assessed based on various methods: E.1 methods are based on task performance, while E.2.a denotes assessment based on a questionnaire. The performance based methods could be further broken down into: E.1.a.i (monocular procedure with object/instrument held in one hand), E.1.a.ii (monocular procedure with object/instrument held in both hands), E.1.b (binocular procedure), E.1.c (a combination of the previous methods), and E.1.d (some other method).

Examples

### load data
dat <- get(data(dat.bourassa1996))

### calculate log(OR) and corresponding sampling variance with 1/2 correction
dat <- escalc(measure="OR", ai=lh.le, bi=lh.re, ci=rh.le, di=rh.re, data=dat, add=1/2, to="all")

### overall association between handedness and eyedness
res <- rma(yi, vi, data=dat, subset=sex=="combined")
res
predict(res, transf=exp, digits=2)