Preference as a function of active interresponse times: a test of the active time model

In this article, we describe a test of the active time model for concurrent variable interval (VI) choice. The active time model (ATM) suggests that the time since the most recent response is one of the variables controlling choice in concurrent VI VI schedules of reinforcement. In our experiment, pigeons were trained in a multiple concurrent similar to that employed by Belke (1992), with VI 20-s and VI 40-s schedules in one component, and VI 40-s and VI 80-s schedules in the other component. However, rather than use a free-operant design, we used a discrete-trial procedure that restricted interresponse times to a range of 0.5-9.0 s. After 45 sessions of training, unreinforced probe periods were mixed with reinforced training periods. These probes paired the two stimuli associated with the VI 40-s schedules. Further, the probes were defined such that during their occurrence, interresponse times were either "short" (0.5-3.0 s) or "long" (7.5-9.0 s). All pigeons showed a preference for the stimulus associated with the relatively rich VI 40-s schedule--a result mirroring that of Belke. We also observed, though, that this preference was more extreme during long probes than during short probes--a result predicted by ATM.     

DISCRIMINATION OF VARIABLE SCHEDULES IS CONTROLLED BY INTERRESPONSE TIMES PROXIMAL TO REINFORCEMENT

In Experiment 1, food‐deprived rats responded to one of two schedules that were, with equal probability, associated with a sample lever. One schedule was always variable ratio, while the other schedule, depending on the trial within a session, was: (a) a variable‐interval schedule; (b) a tandem variable‐interval, differential‐reinforcement‐of‐low‐rate schedule; or (c) a tandem variable‐interval, differential‐reinforcement‐of‐high‐rate schedule. Completion of a sample‐lever schedule, which took approximately the same time regardless of schedule, presented two comparison levers, one associated with each sample‐lever schedule. Pressing the comparison lever associated with the schedule just presented produced food, while pressing the other produced a blackout. Conditional‐discrimination accuracy was related to the size of the difference in reinforced interresponse times and those that preceded it (predecessor interresponse times) between the variable‐ratio and other comparison schedules. In Experiment 2, control by predecessor interresponse times was accentuated by requiring rats to discriminate between a variable‐ratio schedule and a tandem schedule that required emission of a sequence of a long, then a short interresponse time in the tandem's terminal schedule. These discrimination data are compatible with the copyist model from Tanno and Silberberg (2012) in which response rates are determined by the succession of interresponse times between reinforcers weighted so that each interresponse time's role in rate determination diminishes exponentially as a function of its distance from reinforcement.     

The latent variable approach as applied to transitive reasoning

We discuss the limitations of hypothesis testing using (quasi-) experiments in the study of cognitive development and suggest latent variable modeling as a viable alternative to experimentation. Latent variable models allow testing a theory as a whole, incorporating individual differences with respect to developmental processes or abilities in the model. Experiments, in contrast, aim at testing hypotheses that refer to a specific part of a theory; also they ignore individual differences or model the individual differences using age group as a proxy for developmental stage. Drawing on a sample of 409 5–13-year olds, we demonstrate the advantages of latent variable models in the area of transitive reasoning. A comparison of three models showed that the latent variable model that represented fuzzy trace theory had a better fit than the models representing Piaget's theory or linear ordering theory.     

What makes a hypothetical construct “hypothetical”? Tracing the origins and uses of the ‘hypothetical construct’ concept in psychological science

The “hypothetical construct” has been an important concept in philosophy of science for the past half century. References to the concept date as far back as 1943 (Loomba, 1943). Inconsistencies in the use of the term and the related ‘intervening variable’ concept prompted MacCorquodale and Meehl (1948) to distinguish the two concepts and propose conventions for their employment in psychological discourse. They recommended that ‘hypothetical construct’ designates theoretical concepts that “refer to processes or entities that are not directly observed” and, thus, fail to meet the requirements of intervening variables (p. 104). It is interesting to speculate what makes a hypothetical construct “hypothetical.” The motivation for attaching “hypothetical” to constructs is not always immediately apparent. The aim of this paper is to trace the origins of the expression ‘hypothetical construct’, delineate its employment in psychology, and explore the ontological and epistemological presuppositions that underlie conceptions of hypothetical constructs.     

Illegitimate concept equating in the partial fusion of construct validation theory and latent variable modeling

There has come to exist a partial fusion of construct validation theory and latent variable modeling at the center of which is located a practice of equating concepts such as construct, factor, latent variable, concept, unobservable, unmeasurable, underlying, hypothetical variable, theoretical term, theoretical variable, intervening variable, cause, abstractive property, functional unity, and measured property. In the current paper we: a) provide a structural explanation of this concept equating; b) provide arguments to the effect that it is illegitimate; c) suggest that the singular reason for the presence of construct in the literature of the social and behavioral sciences is to mark an allowance taken by the social and behavioral scientist to obliterate the concept/referent distinction that is foundational of sound science.     

Bilateral Reminiscence in Inverted-Reversed Printing

Reported is a study of bilateral reminiscence in printing inverted-reversed alphabetic letters. Independent variables were the printing-Hand Sequence (left-to-right vs. right-to-left), and the Interpolated Activity (control vs. upright reading vs. inverted reading). These variables were factorially combined in a 2 × 3 design with 30 Ss per cell. On second-hand performance, the upright groups were found to be superior to the combined inverted and control groups under both sequence conditions. However, the inverted group was superior to the control group only in the left-to-right condition and not in the right-to-left condition. This latter result was discussed as possibly being due to the specialization of the cerebral hemispheres for certain types of processing activities. Implications of this hypothesis were pointed out for further research, and for possible mechanisms producing reactive inhibition in the central nervous system.     

Transverse shear surface wave in a functionally graded material infinite half space

The variable substitution and power-series techniques are used for the asymptotic analytical derivation of the governing equation of a transverse surface wave. The results reveal that the transverse wave can propagate along the surface of a functionally graded infinite half space in various modes, and that their dispersion relations are normal. For certain cases, energy is concentrated on the surface region to a depth of several wavelengths. A new theoretical foundation based on the transverse surface wave can be provided for graded-material characterization by experimental measurement. Some phenomena of seismic wave propagation may also be explained.     

Mental states as generalizations from experience: a neuro-computational hypothesis

The opposition between behaviour- and mind-reading accounts of data on infants and non-human primates could be less dramatic than has been thought up to now. In this paper, I argue for this thesis by analysing a possible neuro-computational explanation of early mind-reading, based on a mechanism of associative generalization which is apt to implement the notion of mental states as intervening variables proposed by Andrew Whiten. This account allows capturing important continuities between behaviour-reading and mind-reading, insofar as both are supposed to be just different kinds of generalization from perceptual experience. Specifically, I will argue that the projection of inner experiences to others which is involved in early mind-reading does not imply a computational leap beyond associative generalization from perceptual experience.