A motor theory of speech perception, initially proposed to account for results of early experiments with synthetic speech, is now extensively revised to accommodate recent findings, and to relate the assumptions of the theory to those that might be made about other perceptual modes. According to the revised theory, phonetic information is perceived in a biologically distinct system, a ‘module ’ specialized to detect the intended gestures of the speaker that are the basis for phonetic categories. Built into the structure of this module is the unique but lawful relationship between the gestures and the acoustic patterns in which they are variously overlapped. In consequence, the module causes perception of phonetic structure without translation from preliminary auditory impressions. Thus, it is comparable to such other modules as the one that enables an animal to localize sound. Peculiar to the phonetic module are the relation between perception and production it incorporates and the fact that it must compete with other modules for the same stimulus variations.

During sensory-guided motor tasks, information must be transferred from arrays of neurons coding target location to motor networks that generate and control movement. We address two basic questions about this information transfer. First, what mechanisms assure that the different neural representations align properly so that activity in the sensory network representing target location evokes a motor response generating accurate movement toward the target? Coordinate transformations may be needed to put the sensory data into a form appropriate for use by the motor system. For example, in visually guided reaching the location of a target relative to the body is determined by a combination of the position of its image on the retina and the direction of gaze. What assures that the motor network responds to the appropriate combination of sensory inputs corresponding to target position in body- or arm-centered coordinates ? To answer these questions, we model a sensory network coding target p...

It is argued that the following three properties are foundations of robust robot navigation: ffl The use of landmarks (and, in particular, the use of a compass sense), ffl the use of canonical paths, and ffl the use of topological rather than geometrical maps. Some examples of successful animal navigation are presented that support this view. We have performed initial experiments with mobile robots to investigate mechanisms suitable to implement such navigational architectures. Experiments concerning navigation by dead reckoning are presented, and a differential light compass is introduced to aid robot navigation. 1 Introduction Most of the work to date concerning navigation of mobile robots uses internal geometrical representations of the robot's environment to perform navigational tasks. MOBOT III, for example, constructs such a geometrical representation autonomously from sensor data ([Knieriemen & v.Puttkamer 91]), other robots use maps supplied by the designer ([Kampmann & Sch...

Abstract not found

You might find this additional information useful... This article cites 72 articles, 23 of which you can access free at:

Abstract — To localize a seen object, the superior colliculus of the barn owl integrates the visual and auditory localization cues which are accessed from the sensory system of the brain. These cues are formed as visual and auditory maps, thus the alignment between visual and auditory maps is very important for accurate localization in prey behavior. Blindness or prism wearing may disturb this alignment. The juvenile barn owl could adapt its auditory map to this mismatch after several weeks training. Here we investigate this process by building a computational model of auditory and visual integration with map adjustment in the deep superior colliculus. The adaptation is based on activity dependent axon developing which is instructed by an inhibitory network. In the inhibitory network, the strength of the inhibition is adjusted by spike timing dependent plasticity(STDP). The simulation results are in line with the biological experiment and support the idea that the STDP is involved in the alignment of sensory maps. The system of the model provides a new mechanism capable of eliminating the disparity in visual and auditory map integration. I.

www.elsevier.com/locate/behavproc The object behind the echo: dolphins (Tursiops truncatus)