Mizuho Osugi - Academia.edu (original) (raw)
Papers by Mizuho Osugi
A total of 9 brushtail possums (Trichosurus vulpecula) were trained to perform a two-manipulanda,... more A total of 9 brushtail possums (Trichosurus vulpecula) were trained to perform a two-manipulanda, conditional discrimination task. The possums learned to press a right lever in the presence of a tone (80 dB(A)) during tone-on trials, and a left lever in the absence of the tone on tone-off trials. Overall sessions of 11 conditions contained tone frequency between 100 Hz and 35 kHz were tested. Each condition contained training and then probe sessions. In training sessions, the possums were presented with tone-on and tone-off trials, pseudo-randomly. Once the possums responded with over 90% accuracy for five consecutive sessions, then probe sessions were introduced. Probe sessions were similar to the training sessions, except that the tone intensity for tone-on trials was reduced by 8 dB(A) across blocks of 20 trials until their response accuracy in a block fall below 60% or reached 24 dB(A). Data were analysed using overall percentages correct and log d analysis. Both measures indicated that overall response accuracy decreased for all possum as tone intensity reduced. Based on these data analyses, threshold values were calculated using the criterions at 75% correct and a log d of 0.48. The threshold values for each possum and across all possums were plotted as a function of the tone frequency to produce an audiogram. A curvilinear regression was fitted for each threshold values. The functions of both measures were very similar. Both audiograms showed that the possums could hear the tones between 100 Hz and 35 kHz, and were most sensitive to tones between 15 and 20 kHz. This experiment involved many difficulties with producing and measuring tones especially outside of human hearing range. Due to these difficulties, several problems and concerns were raised during the experiment, these were discussed in this study and also recommendations for future research were then presented. iii ACKNOWLEDGMENTS I would like to thank my supervisors Prof. Mary Foster and Assoc. Prof Bill Temple for their guidance, support and encouragement. A special thank you to Mary Foster for her exceptional support, kindness, and care and for her wise counsel and prudent suggestions; to this I am eternally grateful. I could not have completed this thesis without you. A big thank you to Dr James McEwen and Dr Eric Messick and to my fellow students in the experimental and applied fields of Psychology, especially the PhD students. I thank you that you were gracious enough to cope with my sudden visits with questions and asking: "do you have five minutes" which sometimes ended with me staying a lot longer. Thank you to Dr Tania Signal for your help and introducing me to the laboratory study in my third year. Thank you also to Lynette and Derek for your reliability in cleaning the experimental room for me. A special thank to my family, to Yukinobu, Masami and Takeshi Osugi and to my grand mother Tamiko Yamaji. I also want to say a special thank you to my second family in New Zealand; to Nonna, Poppa, Gianna, Chiara, Mehmet and Fabien for your endless love, support, encouragement, care and understanding. I love you all. Thank you Derinda and Julie for your wonderful friendship, it is much appreciated. A special thank you to Laurie Williamson and to Ana for proof reading my work, and to both of you for your wonderful support. Finally, I want to thank Jenny Chandler and Rob Bakker. Thanks Jenny for teaching me to use Matlab, and keeping an eye on my experiments and for your valuable skills in building and fixing equipment. Thanks to Rob for your patience in explaining how sound equipment works, when I had very little understanding.
Journal of the Experimental Analysis of Behavior, 2011
Brushtail possums (Trichosurus vulpecula) were trained to press a right lever when a tone was pre... more Brushtail possums (Trichosurus vulpecula) were trained to press a right lever when a tone was presented (a tone-on trial) and a left lever when a tone was not presented (a tone-off trial) to gain access to food. During training the tone was set at 80 dB(A), with a frequency of 0.88 kH for 3 possums and of 4 kH for the other 2. Once accuracy was over 90% correct across five consecutive sessions, a test session was conducted where the intensity of the tone was reduced by 8 dB(A) over blocks of 20 trials until accuracy over a block fell below 60%. After each test session, training sessions were reintroduced and continued until accuracy was again over 90%, when another test session was conducted. This process continued until there were at least five test sessions at that tone frequency. The same procedure was then used with frequencies of 0.20, 0.88, 2, 4, 10, 12.5, 15, 20, 30, and 35 kHz. Percentage correct and d9 decreased approximately linearly for all possums as tone intensity reduced. Both sets of lines were shallowest at the higher frequencies and steepest at the lower frequencies. Hit and false alarm rates mirrored each other at high frequencies but were asymmetric at lower frequencies. Equal d9 contours showed that sensitivity increased from 2 to 15 kHz and continued to be high over 20 to 35 kHz. The possums remained sensitive to the 20 to 35 kHz tones even at low intensities. The present study is the first to report the abilities of possum to detect tones over this range of frequencies and its results support the findings of a microelectrode mapping survey of possums' auditory cortex.
Journal of the Experimental Analysis of Behavior
Brushtail possums (Trichosurus vulpecula) were trained to press a right lever when a tone was pre... more Brushtail possums (Trichosurus vulpecula) were trained to press a right lever when a tone was presented (a tone-on trial) and a left lever when a tone was not presented (a tone-off trial) to gain access to food. During training the tone was set at 80 dB(A), with a frequency of 0.88 kH for 3 possums and of 4 kH for the other 2. Once accuracy was over 90% correct across five consecutive sessions, a test session was conducted where the intensity of the tone was reduced by 8 dB(A) over blocks of 20 trials until accuracy over a block fell below 60%. After each test session, training sessions were reintroduced and continued until accuracy was again over 90%, when another test session was conducted. This process continued until there were at least five test sessions at that tone frequency. The same procedure was then used with frequencies of 0.20, 0.88, 2, 4, 10, 12.5, 15, 20, 30, and 35 kHz. Percentage correct and d' decreased approximately linearly for all possums as tone intensity r...
A total of 9 brushtail possums (Trichosurus vulpecula) were trained to perform a two-manipulanda,... more A total of 9 brushtail possums (Trichosurus vulpecula) were trained to perform a two-manipulanda, conditional discrimination task. The possums learned to press a right lever in the presence of a tone (80 dB(A)) during tone-on trials, and a left lever in the absence of the tone on tone-off trials. Overall sessions of 11 conditions contained tone frequency between 100 Hz and 35 kHz were tested. Each condition contained training and then probe sessions. In training sessions, the possums were presented with tone-on and tone-off trials, pseudo-randomly. Once the possums responded with over 90% accuracy for five consecutive sessions, then probe sessions were introduced. Probe sessions were similar to the training sessions, except that the tone intensity for tone-on trials was reduced by 8 dB(A) across blocks of 20 trials until their response accuracy in a block fall below 60% or reached 24 dB(A). Data were analysed using overall percentages correct and log d analysis. Both measures indicated that overall response accuracy decreased for all possum as tone intensity reduced. Based on these data analyses, threshold values were calculated using the criterions at 75% correct and a log d of 0.48. The threshold values for each possum and across all possums were plotted as a function of the tone frequency to produce an audiogram. A curvilinear regression was fitted for each threshold values. The functions of both measures were very similar. Both audiograms showed that the possums could hear the tones between 100 Hz and 35 kHz, and were most sensitive to tones between 15 and 20 kHz. This experiment involved many difficulties with producing and measuring tones especially outside of human hearing range. Due to these difficulties, several problems and concerns were raised during the experiment, these were discussed in this study and also recommendations for future research were then presented. iii ACKNOWLEDGMENTS I would like to thank my supervisors Prof. Mary Foster and Assoc. Prof Bill Temple for their guidance, support and encouragement. A special thank you to Mary Foster for her exceptional support, kindness, and care and for her wise counsel and prudent suggestions; to this I am eternally grateful. I could not have completed this thesis without you. A big thank you to Dr James McEwen and Dr Eric Messick and to my fellow students in the experimental and applied fields of Psychology, especially the PhD students. I thank you that you were gracious enough to cope with my sudden visits with questions and asking: "do you have five minutes" which sometimes ended with me staying a lot longer. Thank you to Dr Tania Signal for your help and introducing me to the laboratory study in my third year. Thank you also to Lynette and Derek for your reliability in cleaning the experimental room for me. A special thank to my family, to Yukinobu, Masami and Takeshi Osugi and to my grand mother Tamiko Yamaji. I also want to say a special thank you to my second family in New Zealand; to Nonna, Poppa, Gianna, Chiara, Mehmet and Fabien for your endless love, support, encouragement, care and understanding. I love you all. Thank you Derinda and Julie for your wonderful friendship, it is much appreciated. A special thank you to Laurie Williamson and to Ana for proof reading my work, and to both of you for your wonderful support. Finally, I want to thank Jenny Chandler and Rob Bakker. Thanks Jenny for teaching me to use Matlab, and keeping an eye on my experiments and for your valuable skills in building and fixing equipment. Thanks to Rob for your patience in explaining how sound equipment works, when I had very little understanding.
Journal of the Experimental Analysis of Behavior, 2011
Brushtail possums (Trichosurus vulpecula) were trained to press a right lever when a tone was pre... more Brushtail possums (Trichosurus vulpecula) were trained to press a right lever when a tone was presented (a tone-on trial) and a left lever when a tone was not presented (a tone-off trial) to gain access to food. During training the tone was set at 80 dB(A), with a frequency of 0.88 kH for 3 possums and of 4 kH for the other 2. Once accuracy was over 90% correct across five consecutive sessions, a test session was conducted where the intensity of the tone was reduced by 8 dB(A) over blocks of 20 trials until accuracy over a block fell below 60%. After each test session, training sessions were reintroduced and continued until accuracy was again over 90%, when another test session was conducted. This process continued until there were at least five test sessions at that tone frequency. The same procedure was then used with frequencies of 0.20, 0.88, 2, 4, 10, 12.5, 15, 20, 30, and 35 kHz. Percentage correct and d9 decreased approximately linearly for all possums as tone intensity reduced. Both sets of lines were shallowest at the higher frequencies and steepest at the lower frequencies. Hit and false alarm rates mirrored each other at high frequencies but were asymmetric at lower frequencies. Equal d9 contours showed that sensitivity increased from 2 to 15 kHz and continued to be high over 20 to 35 kHz. The possums remained sensitive to the 20 to 35 kHz tones even at low intensities. The present study is the first to report the abilities of possum to detect tones over this range of frequencies and its results support the findings of a microelectrode mapping survey of possums' auditory cortex.
Journal of the Experimental Analysis of Behavior
Brushtail possums (Trichosurus vulpecula) were trained to press a right lever when a tone was pre... more Brushtail possums (Trichosurus vulpecula) were trained to press a right lever when a tone was presented (a tone-on trial) and a left lever when a tone was not presented (a tone-off trial) to gain access to food. During training the tone was set at 80 dB(A), with a frequency of 0.88 kH for 3 possums and of 4 kH for the other 2. Once accuracy was over 90% correct across five consecutive sessions, a test session was conducted where the intensity of the tone was reduced by 8 dB(A) over blocks of 20 trials until accuracy over a block fell below 60%. After each test session, training sessions were reintroduced and continued until accuracy was again over 90%, when another test session was conducted. This process continued until there were at least five test sessions at that tone frequency. The same procedure was then used with frequencies of 0.20, 0.88, 2, 4, 10, 12.5, 15, 20, 30, and 35 kHz. Percentage correct and d' decreased approximately linearly for all possums as tone intensity r...