- Email: [email protected]
Alteration of human motor response in relation to endogenous and exogenous factors. Part 1: Simple human reaction time and body mass index
ARTICLE IN PRESS Abstracts / HOMO — Journal of Comparative Human Biology 60 (2009) 239–290
287
change throughout life has been vindicated by more recent investigations and now forms an important foundation in clinical dentistry as well as in physical anthropology. 10.1016/j.jchb.2009.02.074
*Murray J Barrett: A life reviewed J.R. Rogers, G.C. Townsend, T. Brown (The University of Adelaide, Australia), [email protected]
Murray James Barrett (1916–1975) graduated from the University of Adelaide’s Bachelor of Dental Surgery program in 1939. He subsequently became a colleague of Professor Thomas Draper Campbell (1893–1967). Draper Campbell’s passion for dental anthropology inspired Barrett to commence a longitudinal growth study of Australian Aboriginals living at Yuendumu in the Northern Territory of Australia. This study, referred to as the Dentgro project, involved the collection of growth data and cultural information about the Wailbri people. Barrett’s application of computer technology enabled him to automate the entry of data derived from the Dentgro study and to develop programs to analyse those data. The serial dental casts obtained by Barrett and his colleagues (over 1700 casts for more than 450 individuals, as well as other growth records) have provided a unique resource for research and for teaching purposes. The casts have been in constant use for more than 40 years, providing insights into many aspects of dental development, including the following: the timing and sequence of tooth emergence; the nature and extent of variation in dental crown size and morphology within and human populations; the patterns of growth in the dental arches over time; the range of occlusal variation between individuals; and the effects of wear on the dentition. The Yuendumu cast collection, representing a population with limited exposure to European customs and dietary habits, continues to attract to the Adelaide School of Dentistry many interstate and overseas researchers with interests in how genetic and environmental factors influence human dental development. 10.1016/j.jchb.2009.02.075
Alteration of human motor response in relation to endogenous and exogenous factors. Part 1: Simple human reaction time and body mass index A. Skurvydas (Lithuanian State Academy of Sport and Physical Education, Kaunas, Lithuania), B. Gutnik (UNITEC, Auckland, New Zealand), [email protected], A.K. Zuoza (Lithuanian State Academy of Sport and Physical Education, Kaunas, Lithuania), D. Nash (UNITEC, Auckland, New Zealand), I.J. Zuoziene, D. Mickeviciene (Lithuanian State Academy of Sport and Physical Education, Kaunas, Lithuania)
Reaction time, or interval between appearance of a signal and the performance of the required motor response, is the concern of sport and clinical psycho-physiologists
ARTICLE IN PRESS 288
Abstracts / HOMO — Journal of Comparative Human Biology 60 (2009) 239–290
and neurobiologists. There is a lack of published data relating reaction time to body mass index. The aim of this work was to establish the relationship between simple reaction time of young adults and their body physique, as represented by body mass index, while they performed a fast motor response. Forty-five healthy, untrained young males were allocated to one of three anthropometric groups, based on their body mass index. Participants performed 100 reaction-time trials with instructions to move a joystick, as quickly as possible, as soon as they detected a single star appearing in the centre of a computer monitor located directly in front of them. Data were statistically allocated into one of seven intervals and data from the mode frequency interval were precisely analysed. Participants from the group with greater modal values of body mass index reacted significantly slower than others. We explain this phenomenon by a smaller relative amount of skeletal muscle tissue (smaller amount of muscle spindles and Golgi tendon organs) as well as a greater value of rotational inertia of the upper extremity for fast motor actions of endomorphic participants. These features required a longer period of preparation (longer reaction time) to the ongoing stimuli. We did not record group lateral differences (between reactions of left and right extremities) based on simple reaction time in any of the groups. We recommend to future researchers the importance of identifying the body mass index of participants prior to testing them for effectiveness of simple sensor-motor reactions. 10.1016/j.jchb.2009.02.076
Palaeohealth and its relationship to culture and the environment: A comparative study of palaeohealth in two precontact Papua New Guinean skeletal samples G. Stannard (Australian National University, Canberra, Australia), [email protected]
This paper will present the results of an investigation into the variation in palaeohealth of two contemporaneous precontact Papua New Guinean populations. Four areas of influence have been identified as potentially affecting the frequencies of various pathologies evident within both the skeletal samples from Motupore Island and Nebira 4. The ecological and geographical setting of each site, the subsistence economies used by the inhabitants, and the different cultures associated with each, all appear to have influenced palaeohealth. Specific pathologies addressed within this comparative study include cribra orbitalia, linear enamel hypoplasia, treponemal infection and dental pathologies such as caries, abscesses and calculus. The variation in access to food, water and other resources seems to be the variable that has had the most influence over the palaeohealth of each of the sites, particularly with respect to the dietary variability of each sample overall. 10.1016/j.jchb.2009.02.077
287
change throughout life has been vindicated by more recent investigations and now forms an important foundation in clinical dentistry as well as in physical anthropology. 10.1016/j.jchb.2009.02.074
*Murray J Barrett: A life reviewed J.R. Rogers, G.C. Townsend, T. Brown (The University of Adelaide, Australia), [email protected]
Murray James Barrett (1916–1975) graduated from the University of Adelaide’s Bachelor of Dental Surgery program in 1939. He subsequently became a colleague of Professor Thomas Draper Campbell (1893–1967). Draper Campbell’s passion for dental anthropology inspired Barrett to commence a longitudinal growth study of Australian Aboriginals living at Yuendumu in the Northern Territory of Australia. This study, referred to as the Dentgro project, involved the collection of growth data and cultural information about the Wailbri people. Barrett’s application of computer technology enabled him to automate the entry of data derived from the Dentgro study and to develop programs to analyse those data. The serial dental casts obtained by Barrett and his colleagues (over 1700 casts for more than 450 individuals, as well as other growth records) have provided a unique resource for research and for teaching purposes. The casts have been in constant use for more than 40 years, providing insights into many aspects of dental development, including the following: the timing and sequence of tooth emergence; the nature and extent of variation in dental crown size and morphology within and human populations; the patterns of growth in the dental arches over time; the range of occlusal variation between individuals; and the effects of wear on the dentition. The Yuendumu cast collection, representing a population with limited exposure to European customs and dietary habits, continues to attract to the Adelaide School of Dentistry many interstate and overseas researchers with interests in how genetic and environmental factors influence human dental development. 10.1016/j.jchb.2009.02.075
Alteration of human motor response in relation to endogenous and exogenous factors. Part 1: Simple human reaction time and body mass index A. Skurvydas (Lithuanian State Academy of Sport and Physical Education, Kaunas, Lithuania), B. Gutnik (UNITEC, Auckland, New Zealand), [email protected], A.K. Zuoza (Lithuanian State Academy of Sport and Physical Education, Kaunas, Lithuania), D. Nash (UNITEC, Auckland, New Zealand), I.J. Zuoziene, D. Mickeviciene (Lithuanian State Academy of Sport and Physical Education, Kaunas, Lithuania)
Reaction time, or interval between appearance of a signal and the performance of the required motor response, is the concern of sport and clinical psycho-physiologists
ARTICLE IN PRESS 288
Abstracts / HOMO — Journal of Comparative Human Biology 60 (2009) 239–290
and neurobiologists. There is a lack of published data relating reaction time to body mass index. The aim of this work was to establish the relationship between simple reaction time of young adults and their body physique, as represented by body mass index, while they performed a fast motor response. Forty-five healthy, untrained young males were allocated to one of three anthropometric groups, based on their body mass index. Participants performed 100 reaction-time trials with instructions to move a joystick, as quickly as possible, as soon as they detected a single star appearing in the centre of a computer monitor located directly in front of them. Data were statistically allocated into one of seven intervals and data from the mode frequency interval were precisely analysed. Participants from the group with greater modal values of body mass index reacted significantly slower than others. We explain this phenomenon by a smaller relative amount of skeletal muscle tissue (smaller amount of muscle spindles and Golgi tendon organs) as well as a greater value of rotational inertia of the upper extremity for fast motor actions of endomorphic participants. These features required a longer period of preparation (longer reaction time) to the ongoing stimuli. We did not record group lateral differences (between reactions of left and right extremities) based on simple reaction time in any of the groups. We recommend to future researchers the importance of identifying the body mass index of participants prior to testing them for effectiveness of simple sensor-motor reactions. 10.1016/j.jchb.2009.02.076
Palaeohealth and its relationship to culture and the environment: A comparative study of palaeohealth in two precontact Papua New Guinean skeletal samples G. Stannard (Australian National University, Canberra, Australia), [email protected]
This paper will present the results of an investigation into the variation in palaeohealth of two contemporaneous precontact Papua New Guinean populations. Four areas of influence have been identified as potentially affecting the frequencies of various pathologies evident within both the skeletal samples from Motupore Island and Nebira 4. The ecological and geographical setting of each site, the subsistence economies used by the inhabitants, and the different cultures associated with each, all appear to have influenced palaeohealth. Specific pathologies addressed within this comparative study include cribra orbitalia, linear enamel hypoplasia, treponemal infection and dental pathologies such as caries, abscesses and calculus. The variation in access to food, water and other resources seems to be the variable that has had the most influence over the palaeohealth of each of the sites, particularly with respect to the dietary variability of each sample overall. 10.1016/j.jchb.2009.02.077