KNOWING BEFORE DOING: DISCRIMINATION BY RATS OF A BRIEF INTERRUPTION OF A TONE

Eight rats' lever presses were reinforced after an interruption in a tone, provided the lever had not been pressed before the tone interruption. After a few sessions, long before the animals reliably refrained from lever pressing before the interruption, the latencies of postinterruption presses (time from the termination of the interruption to the moment of the lever press) dissociated into two classes: short ones for to-be-rewarded presses, and long ones for presses in the other trials, which contained no reward because one or more lever presses had occurred before the interruption. Thus discrimination of impending reinforcement in the current trial occurred before there was evidence of sensitivity to reinforcement in the reinforcement-producing aspect of behavior. This finding is related to Shimp's (1981) contention that the temporal properties of recent behavior are reinforceable, if remembered. The present finding shows that learning to discriminate whether one's behavior has met a contingency, and learning to carry out this behavior, need not go together, implying that memory of temporal properties is probably a necessary but not a sufficient condition for learning the latter.     

ON THE SIGN OF SLOPE IN THE LEARNING OF LINEAR FUNCTIONS

Three groups of subjects were presented with pairs of values ( E and S ) of three different linear functions E = a+bS. In a test phase they had to indicate the E -values that corresponded to the S -values. The values were represented as distances marked on straight lines. Two groups, one a control group, had a positive slope, the third group a negative. The squared sum of the S-E differences was kept constant. All groups had roughly the same performance as measured by the squared sum of deviations from empirical and correct E -values. The learning curves indicated, however, that some learning had taken place in the group with the negative slope. It was concluded that a principle rather than a function was learned.     

HOW PROTHETIC IS THE CONTINUUM OF SMELL?: A further comment on the relation between magnitude and category scales

The relation K =αlog( ψ + q / k ) +β between category scale K and magnitude scale ψ found in previous experiments on loudness and softness of white noise was confirmed for smell data, too. The small increase in variability (SDs) of judgments with magnitude for smell as compared with loudness and softness suggests the substitution of the prothetic-metathetic dichotomy with a quantifiable feature, protheticness, with metathetic continua as the limiting case.     

ON THE PROBLEM OF CATEGORY SCALES IN PSYCHOPHYSICS

E isler , H. On the problem of category scales in psychophysics. Scand. J. Psychol ., 1962, 3 , 81–87.—In the first Part of the paper it is shown that, if three assumptions are granted, the category scale must be logarithmically related to the magnitude scale: K =α log φ +β . In the second part of the paper, the relation K =α log ( kφ+ q) +β is derived, starting from the assumptions that the category scale is a pure function of discrimination and that discrimination is appropriately described by the linear generalization of Weber's law for prothetic continua. We can reconcile these two formulas by defining the zero-point of the magnitude scale as the point where variability vanishes.     

SIMILARITY IN THE CONTINUUM OF HEAVINESS WITH SOME METHODOLOGICAL AND THEORETICAL CONSIDERATIONS

An experiment in which the subjects estimated (a) the ratio and (b) the similarity of pairs of stimuli, consisting of weights, is reported. The report reveals that the relation obtained in earlier investigations between estimated similarity and the two subjective magnitudes of the pair, holds good for the continuum of heaviness too. In connection with this the intraindividual standard deviation of ratio estimates and the problem of internal consistency of a ratio matrix are treated. In a speculative discussion the concept of similarity is scrutinized, the similarity function is tentatively extended to multi-dimensional cases and an attempt is made to connect similarity and discrimination learning.     

The general psychophysical differential equation: A comparison of three specifications

The general psychophysical differential equation, dy/dx = W₂(y)/W₁(x), with the solution y = f(x), where x and y are subjective variables and W₁ and W₂ their subjective Weber functions, is (a) compared with a corresponding functional equation, and (b) studied from a stochastic point of view by error calculus, Methods for evaluating and handling divergences are proposed and illustrated for a number of combinations of Weber functions. It is shown that either the differential: and the functional equations have the same solution or the difference between the solutions is negligible compared to empirical scatter. The error calculus gives the same result: either no error at all or a negligible one.     

Auditory-oral matching behavior in newborns

Twenty-five newborn infants were tested for auditory-oral matching behavior when presented with the consonant sound /m/ and the vowel sound /a/ - a precursor behavior to vocal imitation. Auditory-oral matching behavior by the infant was operationally defined as showing the mouth movement appropriate for producing the model sound just heard (mouth opening for /a/ and mouth clutching for /m/), even when the infant produced no sound herself. With this new dependent measure, the current study is the first to show matching behavior to consonant sounds in newborns: infants showed significantly more instances of mouth opening after /a/ models than after /m/ models, and more instances of mouth clutching after /m/ models than after /a/ models. The results are discussed in the context of theories of active intermodal mapping and innate releasing mechanisms.     

Normal aging increases discriminal dispersion in visuospatial short-term memory

Computational models of cognitive aging propose that age-related decrements in cognitive performance, including short-term memory (STM), result from less distinct stimulus representations. When applied to visual STM, these models predict higher discriminal dispersion (L. L. Thurstone, 1927, Psychophysical analysis, The American Journal of Psychology, 38, 368-389.) in older adults than in younger adults. To test this prediction, we used a change-detection paradigm for visuospatial locations, with different levels of cognitive load (one, three, or five items) and retention interval (100 or 1,000 ms). Adult age differences were not reliable at Load 1, but were substantial at Loads 3 and 5. Effects of retention time did not differ across age groups, suggesting that age-related differences originated mainly from early processing stages. Applying a mixture model to the data revealed age-related increases in discriminal dispersion and decreases in asymptotic discrimination performance (indexing STM capacity). We concluded that age-related declines in discriminal dispersion, in addition to increasing capacity limitations, impair visual STM performance with advancing adult age. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Logic in general philosophy of science: old things and new things

This is a personal, incomplete, and very informal take on the role of logic in general philosophy of science, which is aimed at a broader audience. We defend and advertise the application of logical methods in philosophy of science, starting with the beginnings in the Vienna Circle and ending with some more recent logical developments.