scholarly journals Selective adaptation effects on end-point stimuli in a speech series

1976 ◽  
Vol 20 (1) ◽  
pp. 61-65 ◽  
Author(s):  
James R Sawusch
1993 ◽  
Vol 36 (2) ◽  
pp. 380-395 ◽  
Author(s):  
Joan E. Sussman

Five- to six-year-old children and adults participated in discrimination and selective adaptation speech perception tasks using a synthetic consonant-vowel continuum ranging from [bal to Ida]. In one condition of selective adaptation, attention was focused on the adapting stimulus, the continuum-endpoint ba], with a whispering task. In another condition, attention was focused away from the continuum-endpoint [da] adaptor to contralaterally presented syllables " she " and " see ." Results, compared with two more typical adaptation conditions, indicated that focused attention did not augment selective adaptation effects, particularly for children who showed smaller effects with focused attention on the adaptor. In contrast to adults, children did not significantly change labeling responses after exposure to endpoint-[ba] adaptors, results matching those of Sussman and Carney (1989). However, children did significantly change labeling following exposure to endpoint-[da] adaptors. Discrimination findings with five-formant consonant-vowel and single-formant stimuli supported the importance of acoustic processing for the selective adaptation tasks performed. Together, results support hypotheses of sensory processing differences in younger, normally developing children compared with adults and show that such abilities appear to be related to speech perception skills.


Perception ◽  
1987 ◽  
Vol 16 (4) ◽  
pp. 473-483 ◽  
Author(s):  
Kazunori Morikawa

The model of inhibitory interaction between orientation detectors was examined by prolonged presentation of grating patterns (which was expected to induce orientation-selective adaptation) before measurement of the Zöllner illusion. Adaptation effects were measured under conditions which excluded intrusion by the tilt aftereffect. In experiment 1, illusion magnitude greatly decreased only when the orientation of the adapting grating was the same as that of the inducing lines, which confirmed the first prediction deduced from the model. There was no effect of adapting grating when it was oriented more than 20 ° away from the inducing lines. In experiment 2, adaptation effects were selective not only to orientation but also to spatial frequency. In experiment 3 it was shown that illusion reduction was mediated neither by lowered apparent contrast of the inducing lines nor by retinal adaptation. The results are discussed with respect to the nature of adaptation and possible physiological correlates.


1984 ◽  
Vol 58 (2) ◽  
pp. 663-670 ◽  
Author(s):  
Barbara Burns

The effects of adaptation by stimuli composed of the dimensions of color, orientation and size were measured on the visual persistence of a red vertical 3.5 c/d grating. Adaptation by the stimulus that shared an identical level on each of the three-component dimensions of the test stimulus decreased the visual persistence of the test stimulus. There was no effect of adaptation on visual persistence when the adapting stimulus and test stimulus shared an identical level on zero-, one-, or two-dimensional components. The present results extend the investigation of selective adaptation effects on visual persistence by Meyer, Lawson, Cohen, and Maquire to color, size and orientation. In addition, these results are in excellent agreement with Burns' finding that physically integral stimuli are represented in iconic memory as integral unitary wholes and not as dimensional components.


Perception ◽  
1974 ◽  
Vol 3 (1) ◽  
pp. 87-96 ◽  
Author(s):  
J P Frisby ◽  
J L Clatworthy

Two experiments are described which investigated the possibility that the directional and form aspects of a moving stimulus are coded in separate neural locations. The experiments employed an adaptation paradigm in which sensitivities to grids in optimal apparent movement were measured following an adaptation exposure to a grid in real movement. The postadaptation grids possessed varying degrees of similarity to the adaptation stimulus: they could either have a similar orientation and a similar movement direction, or they could differ on just one of these dimensions, or they could differ on both of these dimensions. Selective adaptation effects were observed which were interpreted as supporting the hypothesis that different form and movement channels exist in the human visual system.


Perception ◽  
1994 ◽  
Vol 23 (6) ◽  
pp. 619-634 ◽  
Author(s):  
Gerald M Long ◽  
Thomas C Toppino

In a series of experiments, the selective-adaptation paradigm was applied to the rotating-trapezoid illusion in an effort to demonstrate neural-adaptation effects in the figural reversal of this classic illusion. Prior to viewing the standard trapezoid, the observer adapted to a rectangle rotating unambiguously in the same direction as the trapezoid or in the opposite direction. In accordance with the neural hypothesis, illusion strength was greatest when the two figures rotated in the same direction and weakest when the two figures rotated in opposite directions. Results were confirmed with two separate dependent variables: the observer's ‘first look’ at the illusion after adaptation and the observer's reversal rate during a test period. These findings were discussed in terms of (a) the basic similarity of results for the rotating trapezoid and reversible figures such as the Necker cube and (b) the need for a multiprocess model of both classes of illusions which emphasizes bottom—up and top—down processes.


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