Andrew Rutherford

• Keele University

Background The link between football (soccer) heading and/or head injury is a concern given the popularity of football worldwide. To assess this link, memory ability of former professional footballers (FPFs) was tested, and self‐reported data on positions played, previous head injuries, and frequency of headers were obtained. Method Data were coll...

Objectives: The link between football (soccer) headings and dementia risk is a concern given the popularity of this sport worldwide. To assess this link, the cognitive ability of former professional players was tested and self-reported estimates on heading frequency were collected. Methods: A survey was co-designed with former players to gather...

Blog post from BJSM blog http://blogs.bmj.com/bjsm/2017/02/15/heading-trouble-dementia-game-changer-football/

This chapter emphasizes that although there are several conceptions and definitions of the sum of squares due to experimental conditions—all providing equivalent estimates—this estimate always is a composite of differences between experimental condition means. It presents the standard analysis of variance (ANOVA) approach to categorical differences...

Mixed effects analysis in regression and analysis of variance (ANOVA) concerns analyses in which some variables are fixed, while others are random. This chapter discusses the multilevel analysis approach to the single factor repeated measures experimental design. It demonstrates the equivalence of the multilevel general linear model (GLM) and the r...

This chapter describes the common organizational structure for the different types of related measures designs provided by Kirk’s account of randomized blocks. Subsequently, repeated measure related designs are discussed. Repeated measures designs are applied much more frequently in psychological research than other randomized block designs, but as...

The type of experimental design determines the particular form of analysis of variance (ANOVA) that should be applied. A wide variety of experimental designs and pertinent ANOVA procedures are available. The simplest of these are independent measures designs. A balanced data design has the same number of subjects in each experimental condition. Whi...

A least squares general linear model (GLM) specification includes more than an equation describing the data in terms of model parameters and error terms. There is also a set of assumptions specifying restrictions on the model parameters and error terms. This chapter presents the typical expression of ANOVA assumptions and the typical expression of...

This chapter focuses on heterogeneous ANCOVA general linear models (GLMs), and discusses two further alternatives to traditional ANCOVA and the ability of heterogeneous regression ANCOVA to ameliorate the problems caused by a relationship between the covariate(s) and the experimental conditions. The basic problem posed by heterogeneous regression A...

The main approach presented in this chapter is known as null hypothesis testing. One of the main concerns and criticisms of null hypothesis testing is that the test outcome is influenced greatly by the size of the sample. In the chapter, different conceptions of effect size and different measures of these conceptions are presented and discussed. Su...

Generally, when the mixed measures design label is applied there is usually theoretical or practical interest in the effects of the fixed factors and the random factors. The type of mixed design employed most frequently in psychology often is labelled a split-plot design. As with all the previous factorial ANOVAs calculated by comparing full and re...

Factorial designs are the most common type of design applied in psychological research. While single factor experiments manipulate a single variable, factorial experiments manipulate two or more variables at the same time. The separate factor effect estimates are termed main effects and compared with the estimates of the effects of experimental con...

ANOVA and ANCOVA: A GLM Approach provides a contemporary look at the general linear model (GLM) approach to the analysis of variance (ANOVA) of one- and two-factor psychological experiments. With its organized and comprehensive presentation, the book successfully guides readers through conventional statistical concepts and how to interpret them in...

Murnane and Phelps (1993) recommend word pair presentations in local environmental context (EC) studies to prevent associations being formed between successively presented items and their ECs and a consequent reduction in the EC effect. Two experiments were conducted to assess the veracity of this assumption. In Experiment 1, participants memorised...

To assess mild head injury effects in adolescent soccer players, neuropsychological performance across school team soccer players, rugby players and noncontact sport players was assessed in a quasi-experimental cross-sectional design. One hundred eighty-five males were tested (ages 13-16; response rate 55%) and 86 contributed data to the analyses a...

The remember-know procedure can be conducted in one or two steps. The one-step procedure does not include a recognition response (old-new) prior to the remember-know response. It is observed consistently that the one-step procedure leads to a more liberal placement of the response criterion, but it is unclear whether recognition accuracy is affecte...

Male players from football and rugby clubs and sportsmen from a variety of noncontact sports clubs at a UK university were compared on biographical and neuropsychological test measures. A data analysis paradigm was developed and employed to control the inflation of Type 1 error rate due to multiple hypotheses testing. Rugby players sustained most h...

The term “Self-Selected Samples" is explained. The nature of selection with respect to such samples is described, its relation to other sampling techniques is considered briefly and a distinction between strong and weak selection is made. Strong self-selected samples are not representative of the population of interest and may very likely differ on...

Footballers run the risk of incurring mild head injury from a variety of sources, including the intentional use of the head to play the ball, known as heading. This paper presents a preliminary exploratory analysis of data collected to examine whether cumulative incidence of mild head injury, or cumulative heading frequency, are related to neuropsy...

A number of studies have suggested that football heading is associated with neuropsychological impairment. However, analyses indicating such a relationship have employed footballers' subjective estimations rather than objective measures of their heading frequency. This is despite frequency estimation research suggesting that such subjective estimat...

Previous research has claimed neuropsychological impairment occurs as a result of professional and amateur football play, and, specifically, football heading. However, much of this research exhibits substantial methodological problems (Rutherford, Stephens, & Potter, 200351. Rutherford , A. , Stephens , R. and Potter , D. 2003. The neuropsycholo...

The ICE model account (e.g., Murnane & Phelps, 1993; Murnane, Phelps, & Malmberg, 1999) of environmental context (EC)-dependent recognition memory is described, and new predictions concerning the effect of multiple presentation ECs are derived. Experiment 1 tested the ICE model predictions in relation to predictions derived from the cue-overload hy...

Association Football (soccer) is the most popular and widespread sport in the world. A significant proportion of the injuries suffered in football are head injuries involving trauma to the brain. In normal play, head trauma frequently arises from collisions, but some researchers have claimed that it also may arise as a consequence of heading the ba...

Many people have speculated over the last 80 years or so about the possibilities of using colored paper to boost response-rates to surveys and questionnaires, and several studies have been carried out. Most of these enquiries report no significant effects from using colored paper, although there have been some exceptions. In this investigation we p...

The ability of environmental-context (EC) familiarity, movement disruption, and the relative strength of memory cues to explain unreliable EC-dependent free-recall memory effects was examined in two experiments. Experiment 1 replicated Smith's (1979, Experiment 1) results confirming that familiarity and disruption cannot account for free-recall EC-...

Traditional analysis of covariance (ANCOVA) assumptions beyond those required for analysis of variance (ANOVA) are described as unnecessary. The problem posed by the most common violation of traditional ANCOVA: heterogeneity of dependent variable on covariate regression coefficients across treatments is considered, as is the relationship between li...

This review points out confusion surrounding the concept and use of mental models from the viewpoints of both human factors and psychology. Noted are the ways in which the notion is conceived according to the needs and approaches of different specialties, and the relationships of mental models to other forms of knowledge representation are consider...

Magnetic Resonance Imaging (MRI) is a new multiplanar imaging technique that clearly demonstrates soft tissue anatomy. The lumbar spines of 26 males have been scanned. From the transverse scans, the position and cross-sectional areas of the muscles of the lumbar region were recorded. Regression analysis was performed to relate these values to trunk...

Confusions surrounding the concept and use of mental models are discussed in a dialogue between an ergonomist and a psychologist. The ways in which the notion is viewed according to the needs and approaches of different specialisms and the relationships of mental models to internal representations, frames and schemata, scenarios and scripts are exp...