Metacognition in psychophysical judgment: an unfolding view of comparative judgments of mental workload.

An experiment is reported in which it was found that when subjects were required to indicate which of two visual extents was more difficult to categorize as "long" or "short," they executed these categorizations and then measured the distance of the representation of each stimulus from the long-short category boundary; the stimulus nearer the boundary was judged to be the more difficult. When they were requested to indicate which was easier to categorize, they selected the alternative that was farther. Coombs's theory of data (1952, 1964) and his unfolding theory of preferential choice (1950, 1964) provided the conceptualization of metacognition in this psychophysical task context. Strong support for the probabilistic version of unfolding theory was obtained from the observed selective effects of laterality on the levels of stochastic transitivity attained for various classes of triples and the reliably longer times for comparisons with bilateral pairs than with unilateral pairs. The semantic congruity effects obtained, together with the changes in the form of the relationship between probability and response time as a function of practice, can be best accounted for by an evidence accrual theory in which the distances from the active reference point are measured and compared with a criterion on each evidence accrual. No support is provided for the view that propositionally based semantic "ease"-"difficulty" codes serve as the basis for these metacognitive comparative judgments of ease and difficulty.     

Regression effect in psychophysical judgment

Psychophysical judgment, like all other kinds of judgment, involves a matching or equating of two different domains. When the judgment involves the matching of values on two perceptual continua, the observer tends, on the average, to constrict the range of his adjustments on whichever variable is placed under his control. When the observer adjusts each variable in turn, two different regression lines are produced. This regression effect presumably occurs whenever the results of the matching judgments yield less than a perfect correlation. Illustrative examples are given for the continua, loudness, vibration, brightness, and duration.     

Regression effect in psychophysical judgment

Psychophysical judgment, like all other kinds of judgment, involves a matching or equating of two different domains. When the judgment involves the mate hing of values on two perceptual continua, the observer tends, on the average, to constrict the range of his adjustments on whichever variable is placed under his control. When the observer adjusts each variable in turn, two different regression lines are produced. This regression effect presumably occurs whenever the results of the matching judgments yield less than a perfect correlation. Illustrative examples are given for the continua, loudness, vibration, brightness, and duration.     

Sequential dependencies and regression in psychophysical judgments

A tendency for judgments of stimulus magnitude to be biased in the direction of the value of the immediately preceding stimulus is found in magnitude estimations of loudness. This produces a bias in the empirical psychophysical function that results in underestimation of the exponent of the unbiased function presumed to relate number and stimulus intensity, N = aSⁿ. The biased judgment can be represented as a power product of focal and preceding stimulus intensity, N_ij= aS ^m S_j ^b. A bias-free estimate of the correct exponent, n, can be obtained from the relation n = m + b.     

Higher order sequential effects in psychophysical judgments

We found that the depth of sequential effects depends on the judgment task. An experiment with squares indicated that stimulus-response pairs up to two trials back were included in the judgment process when subjects were required to make category judgments of size, whereas only the immediately preceding event was incorporated when subjects were making magnitude estimations. In the case of category judgment, interactions between the current stimulus and prior stimuli as well as configural effects indicated that events one and two trials back meet an equivalent function in the judgment process and that these events may jointly operate in one trial. These findings can be explained by a class of models that assume that the position of preceding stimuli relative to the current stimulus is decisive in the judgment process. The multiple-standards model is a representative of this class according to which there are two types of standards: (1) the endpoints of the range as long-term standards and (2) traces of preceding stimuli as short-term standards.     

Higher order sequential effects in psychophysical judgments

We found that the depth of sequential effects depends on the judgment task. An experiment with squares indicated that stimulus-response pairs up to two trials back were included in the judgment process when subjects were required to make category judgments of size, whereas only the immediately preceding event was incorporated when subjects were making magnitude estimations. In the case of category judgment, interactions between the current stimulus and prior stimuli as well as configural effects indicated that events one and two trials back meet an equivalent function in the judgment process and that these events may jointly operate in one trial. These findings can be explained by a class of models that assume that the position of preceding stimuli relative to the current stimulus is decisive in the judgment process. The multiple-standards model is a representative of this class according to which there are two types of standards: (1) the endpoints of the range as long-term standards and (2) traces of preceding stimuli as short-term standards.     

The need for process research on psychophysical judgment: comments on "Ratio and subtractive processes in psychophysical judgment" by Veit

This article is a commentary on Veit's article "Ratio and Subtractive Processes in Psychophysical Judgment." Veit's article makes an important contribution to the area of psychophysical judgment by providing a systematic approach that combines measurement and psychological theory. Using multi-factor designs and a cross-task scale-invariance criterion, Veit shows how to concurrently examine the integration rule, response-transformation function, and psychophysical function for judgment tasks. The need to expand this methodology to further understand the operations and processes underlying psychophysical judgment is stressed in the present article, and an illustration involving feedback mechanisms is provided.     

Direct quantitative judgments of sums and a two-stage model for psychophysical judgments

Judged magnitudes of differences between stimuli have previously been shown to support a two-stage interpretation of magnitude estimation, in which input transformations and output transformations are each describable as power functions. In an effort to provide support for the model independent of the difference estimation procedure. the present investigation employed two additional judgment tasks. We obtained magnitude judgments and category judgments of the combined magnitudes (sums) of paired weights from two groups of Ss. Values of the inferred input exponent k calculated from the two sets of data were very similar and were also remarkably similar to the exponent previously calculated from magnitude estimations of differences between weights. The output exponent calculated from magnitude judgments of sums described a concave upward function; however. the similar function describing category judgments was essentially linear. These results show that the inferred input exponent is not the result of the difference estimation task, and in addition provides support for the contention that the interval scale may be a less biased sensory measure than the magnitude scale. The introduction of an additive constant to the model improved its fit to the data but the rule by which it was introduced made very little difference.     

Rats' lever-press durations as psychophysical judgments of time

Hungry rats received food following lever-press durations exceeding a minimum value, which ranged from 0 to 6.4 sec. When no intertrial intervals separated successive presses, modal press durations remained at very short values as the minimum value required for food was increased. This was particularly true immediately after a food presentation. When an 8-sec intertrial interval followed each lever release, modal press durations were always at or beyond the minimum value required for food, and outcome of the preceding press had no effect on press duration. Possible reasons for the effects of intertrial intervals included punishment of short presses, increased delay of reinforcement of short presses, and reduced density of reinforcement. In addition, functions relating discrete-trials lever-press duration to minimum duration required for food were found to be qualitatively and quantitatively similar to the power functions recently proposed by Catania (1970) for interresponse time and response latency. This similarity was taken as support for a general psychophysical law of temporal judgments.     

On the mental representation of negative numbers: Context-dependent SNARC effects with comparative judgments

In one condition, positive and negative number pairs were compared in separate blocks of trials. In another condition, the positive and the negative number pairs were intermixed. In the intermixed condition, comparisons involving negative numbers were faster with the left hand than with the right, and comparisons were faster with the right hand than with the left hand with the positive numbers; that is, a spatial numerical association of response codes (SNARC) effect was obtained, in which the mental number line was extended leftward with the negative numbers. On the other hand, in the blocked condition, a reverse SNARC effect was obtained with the negative numbers; that is, negative number pairs have the same underlying spatial representation as the positive numbers in this context. Nongraded semantic congruity effects, obtained in both the blocked and the intermixed conditions, are consistent with the idea that magnitude information is extracted prior to the generation of discrete semantic codes.     

An alternative view of the mental lexicon

An essential aspect of knowing language is knowing the words of that language. This knowledge is usually thought to reside in the mental lexicon, a kind of dictionary that contains information regarding a word's meaning, pronunciation, syntactic characteristics, and so on. In this article, a very different view is presented. In this view, words are understood as stimuli that operate directly on mental states. The phonological, syntactic and semantic properties of a word are revealed by the effects it has on those states.     

Humanness beliefs about behavior: An index and comparative human-nonhuman behavior judgments

Social psychological research suggests that two distinct dimensions describe lay conceptions of humanness: a species-typical sense (i.e., human nature) and a species-unique sense (i.e., human uniqueness). Although these two senses of humanness have been discerned among psychological traits and states, there has been no systematic research into lay beliefs about the humanness of human behaviors. Using a range of 60 prosocial, nonsocial, and antisocial behaviors, it was demonstrated that people discriminate between species-typical and species-unique behaviors and that the capacity to perform species-unique behaviors distinguishes humans from animals, whereas the capacity to perform species-typical behaviors distinguishes humans from robots. Behaviors that exemplify the two senses of humanness are identified, and data representing rankings, raw scores, and z-scores in two indices of species typicality and species uniqueness are provided. Taken together, these findings expand our understanding of lay conceptions of humanness and provide researchers of humanness with a wider range of validated stimuli to probe the boundaries of humanity.     

Two models for psychophysical judgment: Scale invariance with changes in stimulus range

Two scaling models are investigated, each of which includes parameters which reflect variation in the use of judgmental categories. In one model, response categories are represented as successive intervals on an underlying sensory continuum. In the other, they are represented as points. Psychophysical scales based upon either of these models are invariant up to a linear transformation when the range of stimulus magnitudes is manipulated. Successive intervals scale values obtained from magnitude estimates are also linearly invariant with changes in stimulus range. Similarities in the proximity functions for the two judgment models are examined.     

The effect of the induction of involvement on psychophysical judgments

The present investigation was based on the concept of invariance, which holds that identical principles govern the judgment of stimuli arrayed on both physically and socially defined scales. Two experiments were conducted in which involvement was manipulated through the use of instructions presented in conjunction with category judgments obtained in a training session. This was followed by an anchor session. Experiment 1 employed a series of weights as stimuli, while Experiment 2 used random pattern dot slides. The experiments were similar, except for the inclusion of two additional features in the weight study. These were: (1) positive feedback, introduced as an independent variable between the judgment sessions and tested for its effect as an enhancer of involvement; and (2) two stimuli in the anchor session not part of the original stimulus series. These weights provided a test for the generality of involvement set. Among various hypotheses tested in both studies was the expectancy that the introduction of involvement associated with the formation of a judgment scale would lessen the impact of an anchor on judgment. This expectancy was based on the observed effects of involvement in social judgment contexts. Results of both experiments supported the judgment maintenance hypothesis.     

Evidencefor implicitscaling in comparative judgment

In two experiments, we examined the effects of manipulating the density of stimuli on comparison difficulty in a comparative judgment task. In Experiment 1, subjects were slower at judging the relative size of a pair when the members were adjacent items in the linear order than when the members were separated by items of intervening magnitudes. In Experiment 2, the advantage of choosing the larger rather than the smaller of two large-stimuli (e.g., the congruity effect) increased when the linear order included many small items. In contrast, the advantage of choosing the smaller of two small items increased when the linear order included many large items. The applicability of the range-frequency theory (Parducci,1965) to these results is discussed.