Formation of transitivity in conditional matching to sample by pigeons

Four homing pigeons were trained over 5 months in a zero-delay, “arbitrary” matching-to-sample procedure with sample and comparison stimuli presented on any of three response keys. Birds were also required to complete a fixed-ratio 10 requirement on both sample and comparison stimuli to terminate their presentation. The procedure resulted in the establishment of relations that were not specifically trained and that can be characterized by the property of transitivity in a stimulus equivalence context. This result was in contrast with the findings obtained from most previous research with nonhuman subjects.     

Contrary-to-duty obligations

We investigate under what conditions contrary-to-duty (CTD) structures lacking temporal and action elements can be given a coherent reading. We argue, contrary to some recent proposals, that CTD is not an instance of defeasible reasoning, and that methods of nonmonotonic logics are inadequate since they are unable to distinguish between defeasibility and violation of primary obligations. We propose a semantic framework based on the idea that primary and CTD obligations are obligations of different kinds: a CTD obligation pertains to, or pre-supposes, a certain context in which a primary obligation is already violated. This framework is presented initially as an extension of Standard Deontic Logic (SDL), a normal modal logic of type KD, and is illustrated by application to a series of examples. The concluding section is concerned with some resemblances between CTD and defeasible reasoning. We show first that the SDL-based framework contains a flaw and must be adjusted. A discussion of possible adjustments, including an alternative treatment in terms of a preference-based semantics, reveals difficulties that are reminiscent of problems in defeasible reasoning and intensional accounts of defeasible conditionals.     

Detachment and defeasibility in deontic logic

The purpose of the paper is to present a logical framework that allow to formalize a kind of prima facie duties, defeasible conditional duties, indefeasible conditional duties and actual (indefeasible) duties, as well as to show their logical interconnections.     

CONDITIONAL DISCRIMINATION VS. MATCHING TO SAMPLE: AN EXPANSION OF THE TESTING PARADIGM

A subject's performance under a conditional-discrimination procedure defines conditional relations between stimuli: “If A1, then B1; if A2, then B2.” The procedure may also generate matching to sample. If so, the stimuli will be related not only by conditionality, but by equivalence: A1 and B1 will become equivalent members of one stimulus class, A2 and B2 of another. One paradigm for testing whether a conditional-discrimination procedure has generated equivalence relations uses three sets of stimuli, A, B, and C, three stimuli per set. Subjects learn to select Set-B and Set-C comparisons conditionally upon Set-A samples. Having been explicitly taught six sample-comparison relations, A1B1, A1C1, A2B2, A2C2, A3B3, and A3C3, subjects prove immediately capable of matching the B- and C-stimuli; six new relations emerge (B1C1, B2C2, B3C3, C1B1, C2B2, C3B3). The 12 stimulus relations, six taught and six emergent, define the existence of three three-member stimulus classes, A1B1C1, A2B2C2, and A3B3C3. This paradigm was expanded by introducing three more stimuli (Set D), and teaching eight children not only the AB and AC relations but DC relations also—selecting Set-C comparisons conditionally upon Set-D samples. Six of the children proved immediately capable of matching the B- and D-stimuli to each other. By selecting appropriate Set-B comparisons conditionally upon Set-D samples, and Set-D comparisons conditionally upon Set-B samples, they demonstrated the existence of three four-member stimulus classes, A1B1C1D1, A2B2C2D2, and A3B3C3D3. These larger classes were confirmed by the subjects' success with the prerequisite lower-level conditional relations; they were also able to select Set-D comparisons conditionally upon samples from Sets A and C, and to do the BC and CB matching that defined the original three-member classes. Adding the three DC relations therefore generated 12 more, three each in BD, DB, AD, and CD. Enlarging each class by one member brought about a disproportionate increase in the number of emergent relations. Ancillary oral naming tests suggested that the subject's application of the same name to each stimulus was neither necessary nor sufficient to establish classes of equivalent stimuli.     

Training sequence effects on emergent conditional discriminations: Replication and extension to selection-based training

We examined the replicability and generality of a previously reported training sequence effect on emergent conditional discriminations in the intraverbal naming task. In Experiment 1, a tact–intraverbal (TI) group learned first to vocally label 6 visual patterns and then to intraverbally relate pairs of verbal labels, whereas an intraverbal–tact (IT) group received the same training in the opposite sequence. Emergent conditional discriminations among pattern stimuli were assessed in match-to-sample (MTS) format. Experiment 2 was identical, except vocal tact and intraverbal training were replaced with selection-based training in which the verbal labels were text stimuli. Compared to the IT sequence, the TI sequence resulted in greater mean accuracy at test (Experiment 1), higher yields (Experiment 2), and shorter reaction times (Experiment 2). Experiment 2 data suggested the TI group's performance might be less dependent on intact intraverbal relations relative to the IT group, but related to participants' reports of visualization during intraverbal training. The results suggest the sequence effect is replicable and occurs in experimental preparations commonly used to study derived stimulus relations. They also provide novel support for the hypothesis that participant behavior during training alters sources of stimulus control available at test.     

Behavioural deficiencies of aggressive 8–9 year old boys: An observational study

The nature of aggressive boys' behaviour is examined. Pre-selected matched pairs of aggressive and control boys were observed in a naturalistic setting which facilitated comparison of the way in which recorded behaviours affected their respective peer relationships. A continuous commentary describing the child's interactions with others was recorded simultaneously with the child's speech during school play. These data were transcribed and coded according to activity, social participation, neighbours, and interactions. Individual behavioural items were grouped on the basis of their functional similarity. Marked differences were found between the two groups on certain categories, giving a clear indication of specific deficiencies in the behavioural repertoire of the aggressive boys.     

Assessment to identify learner-specific prompt and prompt-fading procedures for children with autism spectrum disorder

Few studies have evaluated the use of assessment to identify the most efficient instructional practices for individuals with autism spectrum disorder. This is problematic as these individuals often have difficulty acquiring skills, and the procedures that may be efficient with one individual may not be for others. The experimenters conducted instructional assessments to identify the most efficient prompt type (model, partial physical, full physical) and prompt-fading procedure (progressive delay, most-to-least, least-to-most) for teaching auditory–visual conditional discriminations for individuals with autism spectrum disorder. Each assessment was conducted at least twice, and a final generality test combined the most and the least efficient prompt type and prompt-fading procedure for teaching novel auditory–visual conditional discriminations. The results demonstrated learner-specific outcomes for the prompt type assessment, whereas the least-to-most prompt fading procedure was most efficient for all participants.     

The knowledge norm of assertion in dialectical context

This paper aims to show that the Knowledge Norm of Assertion (KNA) can lead to trouble in certain dialectical contexts. Suppose a person knows that p but does not know that they know that p. They assert p in compliance with the KNA. Their interlocutor responds: ‘but do you know that p?’ It will be shown that the KNA blocks the original asserter from providing any good response to this perfectly natural follow-up question, effectively forcing them to retract p from the conversational scoreboard. This finding is not simply of theoretical interest: I will argue that the KNA would allow the retort ‘but do you know that p?’ to be weaponized in strategic communication, serving as a tool for silencing speakers without having to challenge their testimonial contributions on their own merits. Our analysis can thereby provide a new dimension to the study of epistemic injustice, as well as underscoring the importance of considering the norms governing speech acts also from the point of view of non-ideal social contexts.     

条件推理:“演绎”与“概率”两种实验研究范式之比较

本研究通过推理心理学研究中的“演绎”和“概率”两种实验范式设计对同一个班级的大学生参与者(实验一中N=57,实验二中N=43)进行先后两次有关条件推理的实验研究后,得出如下主要结果:(1)推理者在对不同的“纯形式条件命题本身的认可度”以及对由它们各自建构的同类型推理题的推理结果之间的作答反应模式之间的差异都很小且具有较高的一致性;(2)对由不同的“含具体内容的假言命题”本身的认可度之间以及由它们建构的同类型条件推理题的推理结果之间具有较大的差异性;(3)推理者对“演绎”和“概率”两种不同实验范式分别建构的内容近似的推进题进行推理时具有大致相同的作答反应趋势。由此可以推论推理者在“概率推理实验范式”中的作答或推理结果可以被视为只是对“演绎推理实验范式”的相应推理题给出“概率解”的心理加工过程。