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 listening heart and the chi square: clinical and empirical perceptions in the family therapy of anorexia nervosa

Clinical and empirical methods are commonly considered to be complementary activities. However, many people in the fields of mental health and social welfare espouse a strong adherence to experimental, scientific methods for the evolution of theory and practice and consider only that which has been experimentally tested as‘really true”. Others would propose the clinical method as the main source of useful knowledge and are suspicious of enumeration and quantification as sources of useful information. Formal, empirical methodology is well and extensively described whilst there is less systematic exposition of the clinical method. Family therapy evolved in a context in which activity was visible and the emerging discipline was propelled by a theoretical framework with strongly scientific origins that was critical of the exclusive clinical method of pre-existing psychotherapies. This paper describes some of the clinically based contributions to the family therapy of anorexia nervosa and compares this information with that which comes out of the Maudsley trials of psychotherapies in anorexia nervosa.     

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.     

Beneficial factors in family discussion groups of a psychiatric day clinic: perceptions by the therapeutic team and the families of the therapeutic process

This paper reports a pilot investigation of the perception of helpful events by the therapeutic team and the families in two family discussion groups (FDGs) of a psychiatric day clinic. All participants of the FDG, including therapists and observers, filled in questionnaires measuring events helpful for the individual, for the family and for the group after each FDG session. The results showed that the therapeutic team and the families diverged in their overall perception of which factors were important in family discussion group therapy. The therapeutic team saw the relational climate and the structural aspects of the group (including group involvement and support from the group), and specific therapeutic interventions as more helpful than the families. The process aspects in the group members (including the experiencing of communality and gaining insight) were, on the other hand, more frequently mentioned by the families than by the therapeutic team. The clinical implications of these findings and suggestions for future research are discussed.