Time course of gustatory adaptation

Subjects rated the taste of solution-soaked filter paper over time. Adaptation was complete for all compounds at most concentrations. The course was exponential and the same for all conditions. Adaptation was not the result of stimulus loss. The filter-paper technique allows a greater stability of stimulus than other techniques, hence complete adaptation.     

Time course of recovery from gustatory adaptation to NaCl

Recovery from adaptation to NaCl was tested by comparing some relevant parameters of response to the adapting and test stimuli separated by different recovery intervals. The time course of response was determined using magnitude estimations and using the flow chamber for stimulus delivery. The course of recovery for all parameters used was a negatively accelerated function of the rest time, but the recovery rate of different parameters did not prove to be equal. Recovery was fastest for the initial maximum taste magnitude, followed by the time needed for the taste to disappear. The taste effect summed over time and the time required for the taste magnitude to decrease to 30% of its preadapted maximum were the slowest to recover. Although the recovery process proceeded at a rapid rate during the initial period, all parameters remained depressed over a rather long period.     

Time course of recovery from gustatory adaptation to NaCl.

Recovery from adaptation to NaCl was tested by comparing some relevant parameters of response to the adapting and test stimuli separated by different recovery intervals. The time course of response was determined using magnitude estimations and using the flow chamber for stimulus delivery. The course of recovery for all parameters used was a negatively accelerated function of the rest time, but the recovery rate of different parameters did not prove to be equal. Recovery was fastest for the initial maximum taste magnitude, followed by the time needed for the taste to disappear. The taste effect summed over time and the time required for the taste magnitude to decrease to 30% of its preadapted maximum were the slowest to recover. Although the recovery processes proceeded at a rapid rate during the initial period, all parameters remained depressed over a rather long period.     

Influence of the intensity of NaCl solutions on adaptation degree and recovery time course

The degree of adaptation and the time course of recovery after adaptation to NaCl solutions of various intensities were examined by magnitude estimation and simple sensory reaction time using a test stimulus of constant intensity. The results show that the degree of adaptation increased with the adapting concentration following a negatively accelerated function. Similarly, all recovery curves were negatively accelerated functions of the recovery time. The relation between the recovery constant (time necessary to attain two-thirds of normal responsivity) and adapting concentration approximates with both criteria more or less a linear function. Thus the recovery constant is a positively accelerated function of the degree of adaptation. The relationship between concentration and degree of adaptation can be approximated by Beidler’s equation of taste stimulation, while the time course of recovery can be expressed by an exponential equation that can also be related to Beidler’s theory. The two criteria used showed similar deteriorating effects of taste adaptation, indicating that reaction time can also be a useful criterion of the level of sensory responsivity.     

Sequential estimations of time

Sequential estimations of intervals stored and reproduced by either counting or not counting are compared in experiments with single and repeated presentation of the standard interval. In a non-counting condition the estimates show a negative correlation with the last occurring trial throughout the series after one presentation of the standard. Consequently, in an ongoing process the capacity for (the storage and) the recall of time appears to be limited to the most recent event corresponding with the previous estimate. Correlations are lacking when the standard is presented after every estimate because the most recent information is an external constant. The correlations with the last trial recur when relatively long intervals are used, stored on the basis of various sensory cues. When the difference between the number of these cues is minimized, the correlation disappears. Counting never shows sequential correlations since it favors the coding and storage of time as a number of subjective units. The temporal equivalent of that number is constructed from trial to trial, a representation of the complete interval is not available and the subject does not remember his counting rate.     

Adaptation and cross-adaptation of the four gustatory qualities

On the basis of magnitude estimations of solutions of NaCl, quinine sulfate, sucrose, and HCl, a seven-step series of each compound was chosen. The concentration of each compound in the same ordinal position of the series was of approximately the same sensory magnitude. The middle concentration of each series was presented as an adapting stimulus, and the entire series was used to test the effects of 2 min of adaptation on magnitude estimations and quality reports. Both NaCl and sucrose adaptation markedly lowered magnitude estimations of test stimuli of the same compounds for concentrations lower than that of the adapting stimulus, but had little effect on higher concentrations. Cross-adaptation generally enhanced the magnitude estimations over those obtained in initial estimations. Neither adaptation nor cross-adaptation procedures produced quality changes.     

Multidimensional scaling of musical time estimations

The aim of this study was to identify the psycho-musical factors that govern time evaluation in Western music from baroque, classic, romantic, and modern repertoires. The excerpts were previously found to represent variability in musical properties and to induce four main categories of emotions. 48 participants (musicians and nonmusicians) freely listened to 16 musical excerpts (lasting 20 sec. each) and grouped those that seemed to have the same duration. Then, participants associated each group of excerpts to one of a set of sine wave tones varying in duration from 16 to 24 sec. Multidimensional scaling analysis generated a two-dimensional solution for these time judgments. Musical excerpts with high arousal produced an overestimation of time, and affective valence had little influence on time perception. The duration was also overestimated when tempo and loudness were higher, and to a lesser extent, timbre density. In contrast, musical tension had little influence.     

Two-subtest estimations of WAIS-III factor index scores

The reliability and validity of various short forms of the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III; D. Wechsler, 1997) were evaluated in a sample of 100 patients with traumatic brain injury and in a demographically matched subgroup from the standardization sample. All short forms were based on 2-subtest estimations of the respective factor indexes. Although acceptable estimates could be obtained from all short forms for Verbal Comprehension, none of the possible short forms for Perceptual Organization consistently met the minimum criterion regarding the percentage of cases that fell within the 90% confidence interval of the full-length index. It is concluded that short-form estimates of the WAIS-III are not appropriate for clinical use when the goal is to obtain factor indexes.     

Magnitude estimation of short electrocutaneous pulses

Summary A comparison was made of electrocutaneous magnitude estimation data across two experiments with contextual differences not involving stimulus parameters, such as number and range of stimuli and relative position of the standard in the stimulus range. The data were fitted by 2-parameter linear, log-linear and power functions. When the data are fitted by either linear or log-linear equations, both intercept and slope parameters are significantly affected by the different contextual factors. When the data are fitted by a power function, however, only the intercept is altered; the slope remains invariant despite contextual changes introduced in the second experiment.Although the empirically derived psychophysical power law has been applied to magnitude estimation data for all other sensory modalities, its application to electrocutaneous stimuli has been less successful.     

Magnitude estimation of apparent sums and differences

Os first scaled two continua by magnitude estimation: apparent area of circles and loudness of 1,000-Hz tones. They then gave magnitude estimations of apparent sums and apparent differences for IS pairs of stimuli on each of the two continua. The scales for sums and differences were in some cases nearly linearly related to the power function obtained when the same as scaled the underlying continuum. However, systematic departure from linearity was the usual result. The power law exponents obtained were generally smaller than those usually reported for the two sensory continua.     

Magnitude estimates of distance based on object-size

At a fixed distance of 1.5 ft., varying sizes of vertical lines or circles were presented to S.Subjects estimated either apparent size or distance based on relative size. Estimates of line height and circle diameter yielded power functions with exponents of 0.97 and 0.98, respectively. Distance estimates were curvilinearly related to distance predicted from the size/distance ratio. This result is discussed in terms of non-Euclidean space and in relation to the nature of the judgmental task.