A Formal Characterisation of Hamblin’s Action-State Semantics

Hamblin’s Action-State Semantics provides a sound philosophical foundation for understanding the character of the imperative. Taking this as our inspiration, in this paper we present a logic of action, which we call ST, that captures the clear ontological distinction between being responsible for the achievement of a state of affairs and being responsible for the performance of an action. We argue that a relativised modal logic of type RT founded upon a ternary relation over possible worlds integrated with a basic tense logic captures intuitions of the Hamblinian model of imperatives. The logic implements a direct mapping of each of Hamblin’s key concepts: strategies, partial strategies and wholehearted satisfaction.     

Response rate and sensitivity to the molar feedback function relating response and reinforcement rate on VI+ schedules of reinforcement

In 5 experiments, the author examined rats' sensitivity to the molar feedback function relating response rate to reinforcement rate on schedules of reinforcement. These studies demonstrated that, at lower rates of responding, rats' performance on variable ratio (VR), variable interval (VI), and variable interval with linear feedback loop (VI+) schedules was determined largely by reinforcement of interresponse times; response rates were faster on VR than on both VI and VI+ schedules. In contrast, when procedures were adopted to maintain high rates of response, rats showed sensitivity to the molar characteristics of the schedules; they responded as fast on a VI+ schedule as on a VR schedule and faster on both of these schedules than on a yoked VI schedule. When the variance of response rate was manipulated, this factor was noted as an important element in determining sensitivity to the molar characteristics of the schedule.     

A Dissociation between Symbolic Number Knowledge and Analogue Magnitude Information

Semantic understanding of numbers and related concepts can be dissociated from rote knowledge of arithmetic facts. However, distinctions among different kinds of semantic representations related to numbers have not been fully explored. Working with numbers and arithmetic requires representing semantic information that is both analogue (e.g., the approximate magnitude of a number) and symbolic (e.g., what / means). In this article, the authors describe a patient (MC) who exhibits a dissociation between tasks that require symbolic number knowledge (e.g., knowledge of arithmetic symbols including numbers, knowledge of concepts related to numbers such as rounding) and tasks that require an analogue magnitude representation (e.g., comparing size or frequency). MC is impaired on a variety of tasks that require symbolic number knowledge, but her ability to represent and process analogue magnitude information is intact. Her deficit in symbolic number knowledge extends to a variety of concepts related to numbers (e.g., decimal points, Roman numerals, what a quartet is) but not to any other semantic categories that we have tested. These findings suggest that symbolic number knowledge is a functionally independent component of the number processing system, that it is category specific, and that it is anatomically and functionally distinct from magnitude representations.     

Context processing in older adults: evidence for a theory relating cognitive control to neurobiology in healthy aging.

A theory of cognitive aging is presented in which healthy older adults are hypothesized to suffer from disturbances in the processing of context that impair cognitive control function across multiple domains, including attention, inhibition, and working memory. These cognitive disturbances are postulated to be directly related to age-related decline in the function of the dopamine (DA) system in the prefrontal cortex (PFC). A connectionist computational model is described that implements specific mechanisms for the role of DA and PFC in context processing. The behavioral predictions of the model were tested in a large sample of older (N = 81) and young (N = 175) adults performing variants of a simple cognitive control task that placed differential demands on context processing. Older adults exhibited both performance decrements and, counterintuitively, performance improvements that are in close agreement with model predictions.     

Stout,Rawls, and the Idea of Public Reason

Jeffrey Stout claims that John Rawls's idea of public reason (IPR) has contributed to a Christian backlash against liberalism. This essay argues that those whom Stout calls “antiliberal traditionalists” have misunderstood Rawls in important ways, and goes on to consider Stout's own critiques of the IPR. While Rawls's idea is often interpreted as a blanket prohibition on religious reasoning outside church and home, the essay will show that the very viability of the IPR depends upon a rich culture of deliberation in which all forms of reasoning can be put forth for consideration. This clarification addresses the perception that the IPR imposes an “asymmetrical burden” upon believers. In fact, the essay suggests that there are good reasons why believers, qua believers, might endorse the IPR.     

Reception of Morse code through motional, vibrotactile, and auditory stimulation

The potential for communication through the kinesthetic aspect of the tactual sense was examined in a series of experiments employing Morse code signals. Experienced and inexperienced Morse code operators were trained to identify Morse code signals that were delivered as sequences of motional stimulation through up-down displacements (roughly 10 mm) of the fingertip. Performance on this task was compared with that obtained for both vibrotactile and acoustic presentation of Morse code using a 200-Hz tone delivered either to the fingertip through a minishaker or diotically to the two ears under headphones. For all three modalities, the ability to receive Morse code was examined as a function of presentation rate for tasks including identification of single letters, random three-letter sequences, common words, and sentences. Equivalent word-rate measures (i.e., product of percent correct scores and stimulus presentation rate) were nearly twice as high for auditory presentation as for vibrotactile stimulation, which in turn was about 1.3 times that for motional stimulation. The experienced subjects outperformed the inexperienced subjects by amounts that increased with task complexity. For example, the former were able to receive sentences at 18 words/min with motional stimulation, whereas the latter, following 75 h of training, were unable to perform this task. The present results and those of other research with tactual communication systems are compared, particularly regarding estimates of information-transfer rates.     

Perceptual Ambiguity, Gender, and Target Intoxication: Assessing the Effects of Factors That Moderate Perceptions of Sexual Harassment

Subjects read a passage which described an interaction between a man and a woman at an office party. The woman was either sober or intoxicated, and eventually the man engaged in 1 of 3 behaviors which involved varying degrees of sexual innuendo and/or aggression: (a) verbal comment, (b) verbal request, and (c) nonverbal physical display. The results indicated that perceptions did not vary as a function of target person's intoxication in the nonverbal-display condition. On the other hand, in the verbal-comment and verbal-request conditions, subjects in the intoxicated-target-person condition perceived the initiator more favorably than subjects in the sober-target-person condition. In addition, they indicated that perceptions did not vary as a function of target-person intoxication level in the nonverbal-display condition. On the other hand, in the verbal-comment and verbal-request conditions, male subjects were more favorable toward the initiator than toward female subjects.     

A Defense of Backwards in Time Causation Models in Quantum Mechanics

Synthese - This paper offers a defense of backwards in time causation models in quantum mechanics. Particular attention is given to Cramer's transactional account, which is shown to have the...     

Context extinction following conditioning with delayed reward enhances subsequent instrumental responding

In Experiment 1, delayed reward generated low response rates relative to immediate reward delivered with the same frequency. Lister rats exposed to delayed reward subsequently responded at a higher rate in extinction if they received nonreinforced exposure to the conditioning context after instrumental training and prior to test, compared with animals that received home cage exposure. In Experiment 2, a signaled delay of reinforcement resulted in higher rates than an unsignaled delay. Nonreinforced exposure to the conditioning context elevated response rate for subjects in the unsignaled condition relative to a home cage group, but had no effect on response rates for subjects that had received the signaled delay. In Experiment 3, following an unsignaled reinforcement delay, groups receiving either no event or signaled food in the context responded faster in extinction than groups receiving no context exposure or unsignaled food.