Douglas D. Potter

The neuropsychology of heading and head trauma in Association Football (soccer): a review.

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 ball. Although assessments based on biomechanical analyses are equivocal on the potential for brain injury due to football heading, a growing literature seems to support the claim that neuropsychological impairment results from general football play and football heading in particular. However, this review suggests a distinction is required between the neuropsychological effects of concussive and subconcussive head trauma and that all of the neuropsychological studies conducted so far suffer from methodological problems. At best, a few of these studies may be regarded as exploratory. The review concludes that presently, although there is exploratory evidence of subclinical neuropsychological impairment as a consequence of football-related concussions, there is no reliable and certainly no definitive evidence that such impairment occurs as a result of general football play or normal football heading. The neuropsychological consequences of football-related subconcussive effects await confirmatory investigation.

Perceiving rhythm where none exists: Event-Related Potential (ERP) correlates of subjective accenting

Previous research suggests that our past experience of rhythmic structure in music results in a tendency for Western listeners to subjectively accent equitonal isochronous sequences. We have shown in an earlier study that the occurrence of a slightly softer tone in the 8th to 11th position of such a sequence evokes a P300 event-related potential (ERP) response of different amplitudes depending on whether the tone occurs in putatively subjectively accented or unaccented sequence positions (Brochard et al., 2003). One current theory of rhythm processing postulates that subjective accenting is the result of predictive modulations of perceptual processes by the attention system. If this is the case then ERP modulations should be observed at an earlier latency than the P300 and these should be observed in ERPs to both standard and softer tones. Such effects were not observed in our previous study. This was possibly due to the use of a linked-mastoid reference which may have obscured lateralized differences. The aim of the present study was to replicate the previous auditory P300 subjective accenting findings and to investigate the possibility that these effects are preceded by ERP changes that are indicative of rhythmic modulation of perceptual processing. Previous auditory P300 findings were replicated. In addition and consistent with current theories of rhythm processing, early brain ERP differences were observed both in standard and deviant tones from the onset of the stimulus. These left lateralized differences are consistent with a rhythmic, endogenously driven, modulation of perception that influences the conscious experience of equitonal isochronous sequences.

Effect of mild head injury on event-related potential correlates of Stroop task performance.

The effect of mild head injury on event-related potential (ERP) correlates of Stroop task performance was explored with the aim of further elucidating the basis of processing impairments after mild head injury. Computer- and card-based Stroop tasks were employed to assess attention function. A sequence of incongruent color words were presented followed by a sequence of congruent color words (printed in congruent colors). Control performance was equivalent on computer- and card-based versions of the incongruent task and faster on the congruent card task than the preceding congruent computer task. The mild head injury group were as fast as controls on the computer-based task but made more errors. However, they were relatively slower on both the congruent and incongruent parts of the card-based task and made more errors in the incongruent task. ERP correlates of computer-based Stroop task performance suggested a greater allocation of attention resources in the incongruent condition in both groups in the form of relatively greater negativity in the latency range 350 to 450 ms with a distribution consistent with the activation of the anterior cingulate gyrus. In addition the mild head injured group showed relatively greater enhancement than the control group in this latency range in both congruent and incongruent conditions. There was, however no evidence of reduced amplitude P1, N1, N2, or P3b deflections. Trails, digit symbol, digit span and auditory verbal learning tests (AVLT) were also administered. Mild head injured participants were impaired only on the AVLT. The finding of greater ERP negativity in the mild head injured group is consistent with greater allocation of attention resources to achieve equivalent performance in the computer-based Stroop task.

Neuropsychological Impairment as a Consequence of Football (Soccer) Play and Football Heading: Preliminary Analyses and Report on University Footballers

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, 2003). By investigating less committed amateur level footballers, the current study sought to gain some insight into the developmental history of any neuropsychological consequences of football play. University football, rugby and noncontact sports players were compared on a range of biographical and neuropsychological test variables. While playing their chosen sports, rugby players sustained many more head injuries than footballers and noncontact sportsmen, but footballers did not sustain significantly more head injuries than noncontact sportsmen. The number of head injuries sustained predicted Trails B and TAP Divided Attention latencies in a positive fashion. After controlling for the number of head injuries sustained, sport group effects were detected with TAP Divided Attention accuracy scores, with footballers exhibiting poorest performance. After controlling for the number of head injuries sustained, the total amount of heading done by footballers predicted the number of Wisconsin Card Sorting category shifts in a negative fashion. Nevertheless, over interpretation of all of these results should be resisted because of the exploratory nature of the analyses and the possibility that the sport groups may differ in ways other than just the nature of their sports activities. This research was funded by the Wellcome Trust, Grant Ref: 054248.

Neuropsychological Consequence of Soccer Play in Adolescent U.K. School Team Soccer Players

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 after exclusion for recent concussion and overlapping sports participation. Soccer players showed lower premorbid intellectual functioning, but neither soccer players nor rugby players showed neuropsychological decrement compared with noncontact sport players. Cumulative heading did not predict neuropsychological performance. While no specific attribute of soccer was linked with neuropsychological impairment, head injury predicted reduced attention for all participants.

Assessment of Mild Head Injury with ERPs and Neuropsychological Tasks

Abstract Mild head injury can result in the development of persistent symptoms including impairments of memory and attention in a small but significant minority. The problem in assessing these difficulties in such cases is the likely interaction of psychogenic and organic causes. The aim of the present research is to more accurately characterize the nature of these cognitive deficits. Twelve asymptomatic volunteers, who had experienced a mild head injury in the last 3.5 years, were compared to a matched control group. ERPs were recorded during the performance of the paced auditory serial addition task (PASAT) and a 3-stimulus auditory “oddball” task. Verbal paired associate. Trails A and B, Digit Symbol, Rey Figure Recall, NART, and Digit Span were also administered. The mild head injured group showed evidence of a mild impairment of episodic memory, slowing of attention shifting, but no changes in reaction time or error rates in either the “oddball” task or the PASAT. Although there was no evidence of im...

Neuropsychological impairment as a consequence of football (soccer) play and football heading: A preliminary analysis and report on school students (13–16 years)

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 neuropsychological functioning in male adolescent footballers. In a quasi-experimental cross-sectional design, neuropsychological test scores of school team footballers were compared with those of similarly aged rugby players and noncontact sport players. Cumulative mild head injury incidence was estimated using self-reports, and cumulative heading was estimated using a combination of observation and self-reports. No participants had sustained a head injury within 3 months of testing. There was no relationship between head injury and neuropsychological performance, and there were no decrements in either the footballers or the rugby players in comparison with the noncontact sport players. Within the footballers, cumulative heading did not predict any of the neuropsychological test scores. These findings indicate the absence of neuropsychological impairment arising due to cumulative mild head injury incidence, or cumulative heading. Although these null findings may be reassuring to players, parents, and football organizers, we stress that they are preliminary. Further data is being collected from the same populations to provide more reliable effect estimates.

Brief Report: Eye Direction Detection Improves with Development in Autism

Eye direction detection has been claimed to be intact in autism, but the development of this skill has not been investigated. Eleven children with autism and 11 typically developing children performed a demanding face-to-face eye direction detection task. Younger children with autism demonstrated a deficit in this skill, relative to younger control participants. Older children with autism were as accurate as older control participants on this task. In autism, eye direction detection is deficient in late childhood but is typically accurate by adolescence. The implications of this finding for models of social cognitive development in autism are considered.

The effect of cholinergic receptor blockade by scopolamine on memory performance and the auditory P3

Abstract Previous research has suggested a possible link between the effects of scopolamine-induced muscarinic cholinergic receptor blockade on memory and its effect on auditory P3 amplitude and latency. A potential problem with this hypothesis is that, although scopolamine has been reported to increase P3 latency in both visual and auditory modalities, amplitude reductions have been reported only in the case of auditory P3 at Cz. In the present study, subjects were injected intravenously with 5.7 μg/kg of scopolamine or saline in a double blind design. A significant reduction in verbal recognition memory performance was observed. This memory impairment was shown to be largely specific to the encoding of verbal material. The drug effect was of equal magnitude when words of either high or low word frequency were used. Auditory P3 was recorded from frontal central and parietal sites along the midline and over left and right hemispheres. In contrast to a number of earlier reports using a similar drug dose, o...

Gaze Perception Develops Atypically in Children with Autism

The Mindblindness model is the main model of social cognitive development in autism. This model assumes that eye direction detection and eye contact detection develop typically in autism (Baron-Cohen, 1995). The models assumption of maturational development implies that when these skills are abnormal, they must either be absent or developmentally delayed. In contrast, the atypical modularisation hypothesis predicts that these skills can develop deviantly—successfully but atypically—in children with autism. Two computer-based tasks were used to assess eye direction detection and eye contact detection in children with autism and in typically developing children. These skills were developmentally deviant in children with autism. The findings support a model of social cognition in autism that accounts for developmental processes.