Inferential reasoning in old age

Two experiments examined the effects of aging on the kind of inferential reasoning required in comprehending discourse. In Experiment 1 old subjects made more errors than young subjects in solving logical problems framed in everyday language. Unlike the young subjects they had more difficulty when the problems were spoken than when they were written. Experiment 2 revealed that old subjects are inefficient at extracting implicit information during reading; they fail to generate bridging inferences to supply missing information, so that comprehension is restricted to explicitly stated information. The results show that verbal reasoning ability is impaired in old age and that this affects language comprehension in both listening and reading although the deficit is more marked in listening.     

Inferential reasoning by exclusion in pigeons, dogs, and humans

The ability to reason by exclusion (which is defined as the selection of the correct alternative by logically excluding other potential alternatives; Call in Anim Cogn 9:393–403 2006) is well established in humans. Several studies have found it to be present in some nonhuman species as well, whereas it seems to be somewhat limited or even absent in others. As inconsistent methodology might have contributed to the revealed inter-species differences, we examined reasoning by exclusion in pigeons (n = 6), dogs (n = 6), students (n = 6), and children (n = 8) under almost equal experimental conditions. After being trained in a computer-controlled two-choice procedure to discriminate between four positive (S+) and four negative (S−) photographs, the subjects were tested with displays consisting of one S− and one of four novel stimuli (S′). One pigeon, half of the dogs and almost all humans preferred S′ over S−, thereby choosing either by novelty, or by avoiding S− without acquiring any knowledge about S′, or by inferring positive class membership of S′ by excluding S−. To decide among these strategies the subjects that showed a preference for S′ were then tested with displays consisting of one of the S′ and one of four novel stimuli (S′′). Although the pigeon preferentially chose the S′′ and by novelty, dogs and humans maintained their preference for S′, thereby showing evidence of reasoning by exclusion. Taken together, the results of the present study suggest that none of the pigeons, but half of the dogs and almost all humans inferred positive class membership of S′ by logically excluding S−. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.

Inferential reasoning by exclusion in children (Homo sapiens)

The cups task is the most widely adopted forced-choice paradigm for comparative studies of inferential reasoning by exclusion. In this task, subjects are presented with two cups, one of which has been surreptitiously baited. When the empty cup is shaken or its interior shown, it is possible to infer by exclusion that the alternative cup contains the reward. The present study extends the existing body of comparative work to include human children (Homo sapiens). Like chimpanzees (Pan troglodytes) that were tested with the same equipment and near-identical procedures, children aged three to five made apparent inferences using both visual and auditory information, although the youngest children showed the least-developed ability in the auditory modality. However, unlike chimpanzees, children of all ages used causally irrelevant information in a control test designed to examine the possibility that their apparent auditory inferences were the product of contingency learning (the duplicate cups test). Nevertheless, the children's ability to reason by exclusion was corroborated by their performance on a novel verbal disjunctive syllogism test, and we found preliminary evidence consistent with the suggestion that children used their causal-logical understanding to reason by exclusion in the cups task, but subsequently treated the duplicate cups information as symbolic or communicative, rather than causal. Implications for future comparative research are discussed.     

Conflict between egg recognition and egg rejection decisions in common cuckoo (<Emphasis Type="Italic">Cuculus canorus</Emphasis>) hosts

Common cuckoos (Cuculus canorus) are obligate brood parasites, laying eggs into nests of small songbirds. The cuckoo hatchling evicts all eggs and young from a nest, eliminating hosts’ breeding success. Despite the consistently high costs of parasitism by common cuckoos, great reed warbler (Acrocephalus arundinaceus) hosts sometime accept and other times reject parasitic eggs. To explore the cognitive basis of this seemingly maladaptive variation in host responses, we documented differences in egg rejection rates within 1-day periods just before and during the egg-laying cycle across host nests. Hosts rejected cuckoo eggs at 28% of nests during the pre-egg-laying stage, but when cuckoos exchanged the first host egg with the parasite egg, rejections increased to 75%. Even later, when several host eggs remained in a nest after parasitism, rejection rate fell to 37.5%. Experimental parasitism with conspecific eggs on the first and second day of host laying showed a similar directional change in relative rejection rates, dropping from 35 to 0%. Mistakes in egg discrimination (ejection error and ejection cost) were observed mostly in the latter part of the laying cycle, mainly when nests contained 5–6 eggs. These correlational and experimental patterns of egg rejection support a cognitive process of egg discrimination through several shifts in hosts’ optimal acceptance thresholds of foreign eggs. The results are also consistent with the evolution of foreign egg rejection in the context of nest-sanitation (i.e. the removal of foreign objects). Our results suggest that common cuckoo hosts may recognize more eggs than they reject. This implies that the experience of the host with one or more of its own eggs in the clutch is a key factor in rejecting parasite eggs by allowing inspection and learning about their own clutch.     

Inferential reasoning by exclusion in great apes, lesser apes, and spider monkeys

Using the cups task, in which subjects are presented with limited visual or auditory information that can be used to deduce the location of a hidden reward, Call (2004) found prima facie evidence of inferential reasoning by exclusion in several great ape species. One bonobo (Pan paniscus) and two gorillas (Gorilla gorilla) appeared to make such inferences in both the visual and auditory domains. However, common chimpanzees (Pan troglodytes) were successful only in the visual domain, and Bornean orangutans (Pongo pygmaeus) in neither. The present research built on this paradigm, and Experiment 1 yielded prima facie evidence of inference by exclusion in both domains for two common chimpanzees, and in the visual domain for two Sumatran orangutans (Pongo abelii). Experiments 2 and 3 demonstrated that two specific associative learning explanations could not readily account for these results. Because an important focus of the program of research was to assess the cognitive capacities of lesser apes (family Hylobatidae), we modified Call's original procedures to better suit their attentional and dispositional characteristics. In Experiment 1, testing was also attempted with three gibbon genera (Symphalangus, Nomascus, Hylobates), but none of the subjects completed the standard task. Further testing of three siamangs (Symphalangus syndactylus) and a spider monkey (Ateles geoffroyi) using a faster method yielded prima facie evidence of inferential reasoning by exclusion in the visual domain among the siamangs (Experiment 4).     

Effects of perspective and belief on analytic reasoning in a scientific reasoning task

The purpose of these studies was to test the hypothesis that changing perspectives from one's own to another's promotes the engagement of analytic processing and, in turn, reduces the impact of beliefs. In two experiments participants evaluated research vignettes containing belief-consistent and belief-inconsistent conclusions, and indicated whether the data supported a correlation between two variables. Consistent with our hypothesis, the tendency to endorse correlations consistent with prior belief was reduced when participants evaluated the data from the researcher's perspective relative to their own. We also administered the Actively Open Minded Thinking (AOT) scale (Stanovich & West, 2007, 2008), which did not predict belief effects on our task. We did however observe that the AOT was reliably associated with different response strategies: high AOT scorers were more inclined to choose ambiguous response options, such as “no conclusion is warranted”, whereas low scorers evinced a preference for more determinate options (e.g., there is no relationship between the two variables). We interpret our findings in the context of dual process theories of reasoning and from a Bayesian perspective.     

Inferential confusion and obsessive beliefs in obsessive-compulsive disorder

The goal of the present study was to investigate whether inferential confusion could account for the relationships between obsessional beliefs and obsessive-compulsive disorder (OCD). The Inferential Confusion Questionnaire and the Obsessive Beliefs Questionnaire were administered to a sample of 85 participants diagnosed with OCD. Results showed that the relationship between obsessive beliefs and obsessive-compulsive symptoms decreased considerably when controlling for inferential confusion. Conversely, the relationship between inferential confusion and obsessive-compulsive symptoms was not substantially affected when controlling for obsessive beliefs. Since inferential confusion has an overlap with overestimation of threat, a competing hypothesis for the results was investigated. Results indicated that inferential confusion was factorially distinct from overestimation of threat, and that the independent construct of inferential confusion remains significantly related to obsessive-compulsive symptoms when controlling for anxious mood. These results are consistent with the claim that inferential confusion may be a more critical factor in accounting for OCD symptoms than are obsessive beliefs and appraisals.     

Probabilistic reasoning in a classical logic

We offer a view on how probability is related to logic. Specifically, we argue against the widely held belief that standard classical logics have no direct way of modelling the certainty of assumptions in theories and no direct way of stating the certainty of theorems proved from these (uncertain) assumptions. The argument rests on the observation that probability densities, being functions, can be represented and reasoned with naturally and directly in (classical) higher-order logic.     

Interpretation and matching bias in a reasoning task

Subjects were required to construct verifying and falsifying cases of conditional rules in which the presence and absence of negative components was varied. Their responses gave some indication of consistent interpretation of the rules, generally conforming to Wason's (1966) idea of a “defective” truth table. Much of their behaviour, however, seemed to be determined by a task variable in the form of a tendency to construct instances which matched, rather than altered, the values named in the rules.     

Analogy in a general-purpose reasoning system

This paper introduces the various forms of analogy in NARS, a general-purpose reasoning system. NARS is an AI system designed to be adaptive and to work with insufficient knowledge and resources. In the system, multiple types of inference, including analogy, deduction, induction, abduction, comparison, and revision, are unified both in syntax and in semantics. The system can also carry out relational and structural analogy, in ways comparable to (though different from) that in some other models of analogy, such as Copycat and SME. The paper addresses several theoretical issues in the study of analogy, including the specification and justification of analogy, the context sensitivity of analogy, as well as the role analogy plays in intelligence and cognition.     

Natural and contrived experience in a reasoning problem

This study is concerned with the effects of prior experience on a deceptive reasoning problem. In the first experiment the subjects (students) were presented with the problem after they had experienced its logical structure. This experience was, on the whole, ineffective in allowing subsequent insight to be gained into the problem. In the second experiment the problem was presented in “thematic” form to one group, and in abstract form to the other group. Ten out of 16 subjects solved it in the thematic group, as opposed to 2 out of 16 in the abstract group. Three hypotheses are proposed to account for this result.     

Different recognition cues reveal the decision rules used for egg rejection by hosts of a variably mimetic avian brood parasite

Brood parasitism imposes several fitness costs on the host species. To reduce these costs, hosts of avian brood parasites have evolved various defenses, of which egg rejection is the most prevalent. In the face of variable host-parasite mimicry and the costs of egg discrimination itself, many hosts reject only some foreign eggs. Here, we experimentally varied the recognition cues to study the underlying cognitive mechanisms used by the Chalk-browed Mockingbird (Mimus saturninus) to reject the white immaculate eggs laid by the parasitic Shiny Cowbird (Molothrus bonariensis). Immaculate eggs are the only parasite eggs rejected by this host, as it accepts all polymorphic, spotted eggs laid by cowbirds. Using a within-breeding pair experimental design, we tested for the salience of spotting, UV reflectance, and brightness in eliciting rejection. We found that the presence of spotting significantly decreased the probability of rejection while increments in brightness significantly increased rejection frequencies. The cognitive rules underlying mockingbird rejection behavior can be explained by a decision-making model which predicts changes in the levels of rejection in direct relation to the number of relevant attributes shared between host and parasite eggs.     

意义的推理论及其在价值表达式上的运用

本文尝试提出一种新的意义理论--意义的推理说(Inferential Theory),并着重讨论其在价值表达式上的运用.一个满意的意义理论应当对事实表达式与价值表达式都能给出一个融贯的解释,而一些广为人知的意义理论均未能满足这个标准.因而笔者给出意义的推理论的解决方案,并将其运用于事实表达式.     

Eye movements in a simple spatial reasoning task

We report two experiments in which participants read a question about the spatial relationship between two letters, then viewed a visual display containing the letters and were required to respond to the question. The format of the question influenced the nature of the eye movements generated to the visual display. Participants also had a tendency to make additional eye movements in order to generate a fixation sequence that corresponded to the order of the letters in the question. This demonstrates an influence of stored information on eye movement generation, and suggests that the scanpath plays a role in structuring the visual information to facilitate reasoning.     

Conditional reasoning processes in a logical deduction game

Two experiments examined the role of conditional reasoning in the logical deduction game, Mastermind. An analysis suggested that Modus Tollens (MT) reasoning could be used to determine the code structure, for example, in determining if any of the colours in the code are repeated. Consistent with this analysis, Experiment 1 showed that only MT errors are correlated with the number of hypotheses advanced in Mastermind. A subsequent analysis showed that conditional reasoning such as Affirming the Consequent (AC) and Denying the Antecedent (DA) could lead to particularly damaging inferences only when the code was four different colours. When that was known before play, Experiment 2 showed that AC errors, but not MT errors, were significantly correlated with Mastermind hypotheses advanced. A stepwise multiple regression analysis supported these findings: When the solvers knew they were playing a four-colour code, there was a slight diminution in the variance explained by MT errors, and a significant increase in the variance explained by AC errors. An analysis of the number of different possible codes that could be consistent with hypotheses actually played showed that the number of such codes is far fewer when the code consists of four different colours than when its structure is not known. This analysis suggests that reasoners are therefore unlikely to discover many alternative causes for the feedback given when the code consists of four different colours, and it is under these conditions that humans are most likely to engage in AC reasoning.     

Reducing cognitive complexity in a hypothetico-deductive reasoning task

The confusion/non-consequential thinking explanation proposed by Newstead, Girotto, and Legrenzi (1995) for poor performance on Wason's THOG problem (a hypothetico-deductive reasoning task) was examined in three experiments with 300 participants. In general, as the cognitive complexity of the problem and the possibility of non-consequential thinking were reduced, correct performance increased. Significant but weak facilitation (33-40% correct) was found in Experiment 1 for THOG classification instructions that did not include the indeterminate response option. Substantial facilitation (up to 75% correct) was obtained in Experiment 2 with O'Brien et al.'s (1990) one-other-THOG classification instruction. In Experiment 3, a revised version of O'Brien et al.'s pre-test problem format also led to substantial facilitation, even with the use of the standard three-choice THOG classification instruction. These findings are discussed in terms of Newstead et al.'s theoretical proposal and possible attentional factors.