Selective adaptation in speech: Measuring the effects of visual and lexical contexts.

2021 ◽  
Vol 47 (8) ◽  
pp. 1023-1042
Author(s):  
Josh Dorsi ◽  
Lawrence D. Rosenblum ◽  
Arthur G. Samuel ◽  
Serena Zadoorian
Keyword(s):  
2020 ◽  
pp. 174702182098462
Author(s):  
Masataka Yano ◽  
Shugo Suwazono ◽  
Hiroshi Arao ◽  
Daichi Yasunaga ◽  
Hiroaki Oishi

The present study conducted two event-related potential experiments to investigate whether readers adapt their expectations to morphosyntactically (Experiment 1) or semantically (Experiment 2) anomalous sentences when they are repeatedly exposed to them. To address this issue, we manipulated the probability of morphosyntactically/semantically grammatical and anomalous sentence occurrence through experiments. For the low probability block, anomalous sentences were presented less frequently than grammatical sentences (with a ratio of 1 to 4), while they were presented as frequently as grammatical sentences in the equal probability block. Experiment 1 revealed a smaller P600 effect for morphosyntactic violations in the equal probability block than in the low probability block. Linear mixed-effect models were used to examine how the size of the P600 effect changed as the experiment went along. The results showed that the smaller P600 effect of the equal probability block resulted from an amplitude’s decline in morphosyntactically violated sentences over the course of the experiment, suggesting an adaptation to morphosyntactic violations. In Experiment 2, semantically anomalous sentences elicited a larger N400 effect than their semantically natural counterparts regardless of probability manipulation. No evidence was found in favor of adaptation to semantic violations in that the processing cost of semantic violations did not decrease over the course of the experiment. Therefore, the present study demonstrated a dynamic aspect of language-processing system. We will discuss why the language-processing system shows a selective adaptation to morphosyntactic violations.


1989 ◽  
Vol 2 (6) ◽  
pp. 593-607 ◽  
Author(s):  
A. B. Saul ◽  
M. S. Cynader

AbstractCat striate cortical neurons were investigated using a new method of studying adaptation aftereffects. Stimuli were sinusoidal gratings of variable contrast, spatial frequency, and drift direction and rate. A series of alternating adapting and test trials was presented while recording from single units. Control trials were completely integrated with the adapted trials in these experiments.Every cortical cell tested showed selective adaptation aftereffects. Adapting at suprathreshold contrasts invariably reduced contrast sensitivity. Significant aftereffects could be observed even when adapting at low contrasts.The spatial-frequency tuning of aftereffects varied from cell to cell. Adapting at a given spatial frequency generally resulted in a broad response reduction at test frequencies above and below the adapting frequency. Many cells lost responses predominantly at frequencies lower than the adapting frequency.The tuning of aftereffects varied with the adapting frequency. In particular, the strongest aftereffects occurred near the adapting frequency. Adapting at frequencies just above the optimum for a cell often altered the spatial-frequency tuning by shifting the peak toward lower frequencies. The fact that the tuning of aftereffects did not simply match the tuning of the cell, but depended on the adapting stimulus, implies that extrinsic mechanisms are involved in adaptation effects.


1977 ◽  
Vol 44 (2) ◽  
pp. 551-562
Author(s):  
Edmund R. Goedert ◽  
Albert S. Rodwan ◽  
Paul G. Salmon

There is evidence for discrete property analyzers in mammalian visual systems. Research has indicated that prolonged stimulation of such units reduces their sensitivity to subsequent stimulation. Psychophysical studies have employed this effect, termed selective adaptation, to study feature extractors in the human visual system. The purpose of this study was to determine the role of density and deviation in the adaptation figure on the recognition thresholds of simple and complex test figures. A selective adaptation paradigm was employed. A strict property analyzer model suggests that increases in density, deviation, or complexity should lead to an increased recognition time for the test figures. This was not confirmed. The complexity of the test figure had no effect on its recognition time. Both increased density and deviation did have an effect on the recognition times of the test figures. The results thus suggest that contour adaptation involves at least two processes: a general, probably peripheral effect due to the fatigue of visual receptor units and a more specific effect generated by the similarity between test figure and adaptation contours, independent of the site of stimulation.


2001 ◽  
Vol 86 (3) ◽  
pp. 1113-1130 ◽  
Author(s):  
B. J. Malone ◽  
M. N. Semple

Prior studies of dynamic conditioning have focused on modulation of binaural localization cues, revealing that the responses of inferior colliculus (IC) neurons to particular values of interaural phase and level disparities depend critically on the context in which they occur. Here we show that monaural frequency transitions, which do not simulate azimuthal motion, also condition the responses of IC neurons. We characterized single-unit responses to two frequency transition stimuli: a glide stimulus comprising two tones linked by a linear frequency sweep (origin-sweep-target) and a step stimulus consisting of one tone followed immediately by another (origin-target). Using sets of glide and step stimuli converging on a common target, we constructed conditioned response functions (RFs) depicting the variability in the response to an identical stimulus as a function of the preceding origin frequency. For nearly all cells, the response to the target depended on the origin frequency, even for origins outside the excitatory frequency response area of the cell. Results from conditioned RFs based on long (2–4 s) and short (200 ms) duration step stimuli indicate that conditioning effects can be induced in the absence of the dynamic sweep, and by stimuli of relatively short duration. Because IC neurons are tuned to frequency, changes in the origin frequency often change the “effective” stimulus duty cycle. In many cases, the enhancement of the target response appeared related to the decrease in the “effective” stimulus duty cycle rather than to the prior presentation of a particular origin frequency. Although this implies that nonselective adaptive mechanisms are responsible for conditioned responses, slightly more than half of IC neurons in each paradigm responded significantly differently to targets following origins that elicited statistically indistinguishable responses. The prevailing influence of stimulus context when discharge history is controlled demonstrates that not all the mechanisms governing conditioning depend on the discharge history of the recorded neuron. Selective adaptation among the neuron's variously tuned afferents may help engender stimulus-specific conditioning. The demonstration that conditioning effects reflect sensitivity to spectral as well as spatial stimulus contrast has broad implications for the processing of a wide range of dynamic acoustic signals and sound sequences.


2019 ◽  
Author(s):  
Evan Cesanek ◽  
Fulvio Domini

AbstractTo perform accurate movements, the sensorimotor system must maintain a delicate calibration of the mapping between visual inputs and motor outputs. Previous work has focused on the mapping between visual inputs and individual locations in egocentric space, but little attention has been paid to the mappings that support interactions with 3D objects. In this study, we investigated sensorimotor adaptation of grasping movements targeting the depth dimension of 3D paraboloid objects. Object depth was specified by separately manipulating binocular disparity (stereo) and texture gradients. At the end of each movement, the fingers closed down on a physical object consistent with one of the two cues, depending on the condition (haptic-for-texture or haptic-for-stereo). Unlike traditional adaptation paradigms, where relevant spatial properties are determined by a single dimension of visual information, this method enabled us to investigate whether adaptation processes can selectively adjust the influence of different sources of visual information depending on their relationship to physical depth. In two experiments, we found short-term changes in grasp performance consistent with a process of cue-selective adaptation: the slope of the grip aperture with respect to a reliable cue (correlated with physical reality) increased, whereas the slope with respect to the unreliable cue (uncorrelated with physical reality) decreased. In contrast, slope changes did not occur during exposure to a set of stimuli where both cues remained correlated with physical reality, but one was rendered with a constant bias of 10 mm; the grip aperture simply became uniformly larger or smaller, as in standard adaptation paradigms. Overall, these experiments support a model of cue-selective adaptation driven by correlations between error signals and input values (i.e., supervised learning), rather than mismatched haptic and visual signals.


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