The processing of negations in conditional reasoning: A meta-analytic case study in mental model and/or mental logic theory

We present a meta-analytic review on the processing of negations in conditional reasoning about affirmation problems (Modus Ponens: “MP”, Affirmation of the Consequent “AC”) and denial problems (Denial of the Antecedent “DA”, and Modus Tollens “MT”). Findings correct previous generalisations about the phenomena. First, the effects of negation in the part of the conditional about which an inference is made, are not constrained to denial problems. These inferential-negation effects are also observed on AC. Second, there generally are reliable effects of a negation in the clause referred to by the categorical premise, and these referred-negation effects are constrained to the logically fallacious AC and DA inferences. All findings are presented and discussed in relation to contemporary mental model (MM) and mental logic (ML) theories. It is argued that a double-negation elimination hypothesis provides a sufficient explanation of inferential-negation effects within both MM theory and ML theory, if the latter is extended by a validating search for counter examples. Both MM and ML theories adhere to a processing scheme that allows them to incorporate an account of referred-negation effects based on the thesis that counter-example frequency is modulated by the scope of a contrast class delineated by a false affirmative. We conclude that MM and ML theories provide adequate processing schemes to accommodate for the explanatory hypotheses, at least in principle. In practice, both approaches remain equivocal as regards the connectivity and interactivity with long-term memory knowledge invoked in generating, manipulating, and testing the mental representations of negative state of affairs.     

Working memory and counterexample retrieval for causal conditionals

The present study is part of recent attempts to specify the characteristics of the counterexample retrieval process during causal conditional reasoning. The study tried to pinpoint whether the retrieval of stored counterexamples (alternative causes and disabling conditions) for a causal conditional is completely automatic in nature or whether the search process also demands executive working memory (WM) resources. In Experiment 1, participants were presented with a counterexample generation task and a measure of WM capacity. We found a positive relation between search efficiency, as measured by the number of generated counterexamples in limited time, and WM capacity. Experiment 2 examined the effects of a secondary WM load on the retrieval performance. As predicted, burdening WM with an attention-demanding secondary task decreased the retrieval efficiency. Both low and high spans were affected by the WM load but load effects were less pronounced for the most strongly associated counterexamples. Findings established that in addition to an automatic search component, the counterexample retrieval draws on WM resources.     

The relevance of selecting what's relevant: A dual process approach to transitive reasoning with spatial relations

The present paper focuses on the heuristic selection process preceding the actual transitive reasoning process. A part of the difficulty of transitive reasoning lies in the selection of the relevant problem aspects. Two experiments are presented using the paradigm introduced by Markovits, Dumas, and Malfait (1995 Markovits, H., Dumas, C. and Malfait, N. 1995. Understanding transitivity of a spatial relationship: A developmental analysis. Journal of Experimental Child Psychology, 59: 124–141.  [Google Scholar]), in which children were asked to make “higher than” inferences about arrays of coloured blocks. In order to discriminate between genuine transitive inference and a simple strategy of relative position, Markovits et al. interspersed white blocks with the coloured blocks, such that the relative position strategy leads to erroneous responses. However, we argue that the white blocks cause confusion due to their ambiguity, which interferes with the heuristic selection process. Two methodological adaptations were introduced, which are hypothesised to facilitate the selection process and improve transitive reasoning: (1) the white blocks were replaced by coloured blocks, and (2) a less abstract context was added to the experimental design. The colour manipulation leads to a clear increase in the use of a transitive strategy by 9-year-old children; 8-year-old children mainly used the relative position strategy. When adding a context story, 9-year-old children used the transitive strategy regardless of the colour of the interspersed blocks. The overall performance of 8-year-olds improved slightly. These results are interpreted as support for a dual-process model of transitive reasoning.     

Necessity and sufficiency in abstract conditional reasoning

The necessity and sufficiency of the cause relates to the conclusions people draw on everyday conditional inference problems. The current research explores the effects of necessity and sufficiency in an abstract causal context. Three experiments showed that the subjective ratings of necessity and sufficiency diverge from the objective levels: A sufficient and necessary cause is more often labelled as sufficient than a sufficient and not-necessary cause. Likewise, a necessary and sufficient cause is more often labelled necessary than a necessary and not-sufficient cause. In Experiments 1 and 2 we observed that the robust effects of sufficiency on MP and MT, and of necessity on AC and DA found on everyday reasoning generalise to abstract conditionals. There were also partial effects of sufficiency on AC and DA, and of necessity on MP and MT. When the problem presentation is simplified, as in Experiment 3, these partial effects on reasoning disappear. The reasoning results then relate to the objective levels and less to the subjective levels of necessity and sufficiency. This divergence sheds doubt on the idea that reasoners base their inferences on an active assessment of the necessity and/or sufficiency of the causal relation.     

Heuristic Methods for Computer Ethics

The domain of "procedural ethics" is the set of reflective and deliberative methods that maximize the reliability of moral judgment. While no general algorithmic method exists that will guarantee the validity of ethical deliberation, non-algorithmic "heuristic" methods can guide and inform the process, making it significantly more robust and dependable. This essay examines various representative heuristic procedures commonly recommended for use in applied ethics, maps them into a uniform set of twelve stages, identifies common faults, then shows how the resulting stage-by-stage decision-making model could be adapted for general use and for use in computer ethics.     

Levels of consensus and majority and minority influence

Three experiments are reported which examine the effects of consensus information on majority and minority influence. In all experiments two levels of consensus difference were examined; large (82% versus 18%) and small (52% versus 48%). Experiment 1 showed that a majority source had more influence than a minority source, irrespective of consensus level. Experiment 2 examined the cause of this effect by presenting only the source label (‘majority’ versus ‘minority’), only the consensus information (percentages) or both. The superior influence of the majority was again found when either (a) both source label and consensus information were given (replicating Experiment 1) and (b) only consensus information was given, but not when (c) only the source label was given. The results showed majority influence was due to the consensus information indicating more than 50% of the population supported that position. Experiment 3 also manipulated message quality (strong versus weak arguments) to identify whether systematic processing had occurred. Message quality only had an impact with the minority of 18%. These studies show that consensus information has different effects for majority and minority influence. For majority influence, having over 50% support is sufficient to cause compliance while for a minority there are advantages to being numerically small, in terms of leading to detailed processing of its message. Copyright © 2002 John Wiley & Sons, Ltd.     

Treatment approaches for sleep difficulties in college students

College students face many challenges and live experiences that may lead to sleep difficulties, including: varied and changing schedules, repeated deadlines, increased freedom and self-responsibility, and group living arrangements, to name but a few. A high frequency of sleep difficulties is commonly reported among college student and others who encounter similar life experiences. The prevalence of sleep difficulties is explored and a rationale provided for treatment. It is suggested that interventionists need to consider the impact of sleep difficulties on their clients' immediate and long-term functioning. To help psychologists, counsellors, and therapists better ameliorate sleep problems a number of proven techniques are reviewed which are applicable to individuals in both clinical and non-clinical settings.     

Recognition memory for tactile sequences.

In three experiments participants were required to compare the similarity in item order for two temporally separated sequences of tactile stimuli presented to the fingers of the hand. Between-sequence articulatory suppression but not tactile interference impaired recognition accuracy (Experiment 1), and the null effect of tactile interference was not due to the second tactile sequence overwriting the sensory record of the first sequence (Experiment 2). Experiment 3 showed that compared to a condition where the second sequence was presented in the tactile modality only, recognition was enhanced when the second sequence was seen presented either to the hand or on a diagrammatic representation of a hand. A final experiment showed that the effects of Experiment 1 were replicated when the underside of the forearm was used for stimulus presentation, suggesting that the data are not idiosyncratic to the first method of presentation. The pattern of results suggests memory for a sequence of tactile stimuli involves the deployment of strategies utilising a combination of verbal rehearsal and visuo-spatial recoding rather than relying solely on the retention of sensory traces. This is taken to reflect limitations in both the capacity and duration of tactile sensory memory.     

Gestalt Issues in Modern Neuroscience

We present select examples of how visual phenomena can serve as tools to uncoverbrain mechanisms. Specifically, receptive field organization is proposed as a Gestalt-like neural mechanism of perceptual organization. Appropriate phenomena, such as brightness and orientation contrast, subjective contours, filling-in, and aperture-viewed motion, allow for a quantitative comparison between receptive fields and their psychophysical counterparts, perceptive fields. Phenomenology might thus be extended from the study of perceptual qualities to their transphenomenal substrates, including memory functions. In conclusion, classic issues of Gestalt psychology can now be related to modern “Gestalt psychophysics” and neuroscience.     

Brief Comments on Collective Bargaining at the University of Bridgeport: 1974–1987

When Leland Miles arrived as the University of Bridgeport's new president in 1974, the institution had substantial financial problems, declining enrollments, and a newly unionized faculty. This essay is a first-person account of his efforts to work with an immature union and his attempt to save the Liberal Arts at a time of growing student demand for professional degrees.