A computational model of the bottlenose dolphin sonar: Feature-extracting method
A process of echo‐image formation in bottlenose dolphin perception was investigated in our experiments, in which animals were trained to differentiate passive actual echoes recorded beforehand purposely, as well as echo‐like simulated impulses. The results suggest that dolphin, processing echoes within critical interval of time (∼0.2 ms), utilizes the string of three independent, hierarchically organized features (echoes subjective characteristics) being defined by different scales of spectral density oscillation, and energy. Herewith, dolphin is capable to assess features average value over a series of echoes. Distinguishing stimuli, dolphin estimates successively features values from senior to minor, terminating the process at the feature, which contains detectable differences in compared stimuli (the distinctive feature). A procedure of subsequent identification of the reference stimulus can be described by the following decision rule: If the dolphin utilizes some feature as the distinctive one, then i...
Representation and processing of acoustic information in a biomimetic neural network
Abstract : The effectiveness of artificial neural network models depends strongly on the way in which the information to be learned is presented to the network. Use of biologically relevant mechanisms is likely to yield effective syntactic systems as well as understanding the performance of biological systems. We developed a model of the dolphin cochlea and used this model to produce the representations used by a neural network to model the delayed matching-to-sample performance of a bottlenosed dolphin. The model yielded psychophysical functions and matching choice accuracy similar to those obtained from the dolphin.... Artificial neural networks (AN-N), Echolocation Gateway- integrator neural network (GIN)
Cognitive Correlaretes of Physics Achievement of Some Nigeria Senior Secondary Students
Some cognitive correlates of physics achievement of some Nigeria senior secondary students were considered in the study. Specifically, the study examined the relationship between measures of student’s field independency. Cognitive tasks, formal reasoning and their achievement in physics. Purposive and stratified random sampling techniques were employed to obtain a sample of 524 senior secondary two students from six education zones in Kogi State of Nigeria. Three instruments were used. They are science Reasoning Tasks (SRTs). Group Embedded Figures Test (GEFT) and Physics Achievement Test (PAT). Data analysis using multiple regressions reveals that measures of students’ fields’ independency and cognitive tasks predicted student’s achievement in physics generally. However, only measure of field independency predicted students’ achievement in physics in the higher order cognitive demand questions. Measures of formal reasoning had no significant relationship with students’ achievements in physics generally or in higher order cognitive demand questions in physics. However, the overall relationships between measures of field independency, cognitive tasks, formal reasoning and students’ achievement in physics generally and in higher order cognitive demand questions in physics were both significant. Educational implications of these findings were discussed.