Using perceptrons to explore the reorientation task

The reorientation task is a paradigm that has been used extensively to study the types of information used by humans and animals to navigate in their environment. In this task, subjects are reinforced for going to a particular location in an arena that is typically rectangular in shape. The subject then has to find that location again after being disoriented, and possibly after changes have been made to the arena. This task is used to determine the geometric and featural cues that can be used to reorient the agent in the arena. The purpose of the present paper is to present several simulation results that show that a simple neural network, a perceptron, can be used to generate many of the traditional findings that have been obtained using the reorientation task. These results suggest that reorientation task regularities can be explained without appealing to a geometric module that is a component of spatial processing.     

How fallacious is the consequence fallacy?

Timothy Williamson argues against the tactic of criticizing confidence in a theory by identifying a logical consequence of the theory whose probability is not raised by the evidence. He dubs it “the consequence fallacy”. In this paper, we will show that Williamson’s formulation of the tactic in question is ambiguous. On one reading of Williamson’s formulation, the tactic is indeed a fallacy, but it is not a commonly used tactic; on another reading, it is a commonly used tactic (or at least more often used than the former tactic), but it is not a fallacy.     

Response-times at different positions within a sentence

Response latency has often been used to draw inferences about scanning operations in serial lists. Different models have been employed and this experiment tests their predictions when a sentence replaces a serial list. Constituent analysis is used to predict an increase in latency when responding involves crossing a constituent boundary. This prediction is confirmed, and it is found necessary to revise those explanations derived from studies using serial lists to include reference to the syntactic structure of the linguistic material used.     

Use of current explanations in multicausal abductive reasoning

In multicausal abductive tasks a person must explain some findings by assembling a composite hypothesis that consists of one or more elementary hypotheses. If there are n elementary hypotheses, there can be up to 2ⁿ composite hypotheses. To constrain the search for hypotheses to explain a new observation, people sometimes use their current explanation—the previous evidence and their present composite hypothesis of that evidence; however, it is unclear when and how the current explanation is used. In addition, although a person's current explanation can narrow the search for a hypothesis, it can also blind the problem solver to alternative, possibly better, explanations. This paper describes a model of multicausal abductive reasoning that makes two predictions regarding the use of the current explanation. The first prediction is that the current explanation is not used to explain new evidence if there is a simple (i.e., nondisjunctive, concrete) hypothesis to account for that evidence. The second prediction is that the current explanation is used when attempting to discriminate among several alternative hypotheses for new evidence. These hypotheses were tested in three experiments. The results are consistent with the second prediction: the current explanation is used when discriminating among alternative hypotheses. However, the first prediction—that the current explanation is not used when a simple hypothesis can account for new data—received only limited support. Participants used the current explanation to constrain their interpretation of new data in 46.5% of all trials. This suggests that context-independent strategies compete with context-dependent ones—an interpretation that is consistent with recent work on strategy selection during problem solving.     

Comments on “The Ketamine Model of the Near-Death Experience: A Central Role for the N-Methyl-D-Aspartate Receptor”

Although ketamine can induce a state similar to a near-death experience (NDE), there is a striking difference between experiences induced by ketamine used in a recreational context and in an operating room. Ketamine is a noncompetitive antagonist of the N-methyl-D-aspartate receptor, as is ibogaine, the main alkaloid of a shrub used in Central Africa to induce NDEs in a religious context. Ibogaine can also elicit different experiences when used in a hallucinatory context or in initiatic rituals, where a superficial state of coma is induced. These data raise the question of whether the chemically-induced NDE-like experience is related to the use of a particular kind of substance or to a genuine comatose state.     

The effects of category overlap on information-integration and rule-based category learning

In three experiments, we investigated whether the amount of category overlap constrains the decision strategies used in category learning, and whether such constraints depend on the type of category structures used. Experiments 1 and 2 used a category-learning task requiring perceptual integration of information from multiple dimensions (an information-integration task) and Experiment 3 used a task requiring the application of an explicit strategy (a rule-based task). In the information-integration task, participants used perceptual-integration strategies at moderate levels of category overlap, but explicit strategies at extreme levels of overlap--even when such strategies were suboptimal. In contrast, in the rule-based task, participants used explicit strategies, regardless of the level of category overlap. These data are consistent with a multiple systems view of category learning, and suggest that categorization strategy depends on the type of task that is used, and on the degree to which each stimulus is probabilistically associated with the contrasting categories.     

Of Means and Ends: Religion and the Search for Significance

This article attempts to depolarize the concepts of means and ends in the psychology of religion. It is argued that everyone uses his or her religion. However, religion can be used in constructive as well as destructive ways. The critical question is not whether religion is lived or used, as Allport suggested, but how religion is used and to what ends. Thinking about religion as means and ends rather than means or ends offers a framework for organizing the richly diverse forms and functions of religious life, spiritual as well as nonspiritual. It provides a way to conceptualize and study the widely used but poorly defined notion of religious orientation. It also offers a way to evaluate the efficacy of religion in living.     

Prediction of Needle Sharing Among Injection Drug Users1

The aim of the present study was to identify the psychosocial factors associated with the intention and behavior of not sharing used needles and syringes among 459 intravenous drug users (IDUs). The intention to not share used needles was positively associated with personal normative beliefs and self‐efficacy; it was negatively related to the proportion of injections with lending used needles and borrowing syringes from sexual partners. Borrowing used needles was negatively associated with intention whereas loaning syringes was positively related to a negative HIV test result. These results suggest that it is only when a direct personal exposure to HIV infection is possible (borrowing) that intention not to borrow is highlighted. Moreover, being HIV positive appears to reduce loaning used syringes.     

Adolescent males' sexual behavior and contraceptive use: implications for male responsibility

A recent US survey of single 17-21 year old men, indicated that 17.1% used a condom at 1st intercourse and 15.5% used a condom at the most recent intercourse. Withdrawal is also used: 10.0% and 7.4% respectively. Condom use was correlated with being older at 1st intercourse, having a higher educational level, closer association to partner, and sense of male contraceptive responsibility. The data used for this analysis was taken from a sub-sample of 624 sexually active males in 1979. The mean age at 1st intercourse was 14.8 years and mean age at most recent was 18.9 years. The pill was also used at 1st intercourse (8.8%) and a total of 43.5% used some method of contraception. In the most recent intercourse cases, 64.7% used some method of birth control and the pill was used 26.5% , condom 15.5%, and withdrawal 7.4%. Conclusions from this data indicate that male methods are important in teen contraception. Condom use at 1st and most recent intercourse was related to both positive and negative characteristics. It appears that males show some contraceptive responsibility initially but later give the responsibility to females. The declining use of condoms indicates it to be a transitional form of birth control. Programs should promote continued use of condoms since use of the pill is low and unwanted pregnancy risk is high. Communication on contraception should be encouraged, so both partners are aware if neither one is contracepting. With the acquired immunodeficiency syndrome epidemic, condom use takes on a whole new context in relation to the decline in use by adolescents.     

Feature-based versus category-based induction with uncertain categories

Previous research has suggested that when feature inferences have to be made about an instance whose category membership is uncertain, feature-based inductive reasoning is used to the exclusion of category-based induction. These results contrast with the observation that people can and do use category-based induction when category membership is known. The present experiments examined the conditions that drive feature-based and category-based strategies in induction under category uncertainty. Specifically, 2 experiments investigated whether reliance on feature-based inductive strategies is a product of the lack of coherence in the categories used in previous research or is due to the use of a decision-only induction procedure. Experiment 1 found that feature-based reasoning remained the preferred strategy even when categories with relatively high internal coherence were used. Experiment 2 found a shift toward category-based reasoning when participants were trained to classify category members prior to feature induction. Together, these results suggest that an appropriate conceptual representation must be formed through experience with a category before it is likely to be used as a basis for feature induction.     

Correction for Item Response Theory Latent Trait Measurement Error in Linear Mixed Effects Models

Psychometrika - When latent variables are used as outcomes in regression analysis, a common approach that is used to solve the ignored measurement error issue is to take a multilevel perspective on...     

Latent class models for testing monotonicity and invariant item ordering for polytomous items

Two assumptions that are relevant to many applications using item response theory are the assumptions of monotonicity (M) and invariant item ordering (IIO). A latent class model is proposed for ordinal items with inequality constraints on the class-specific item means. This model is used as a tool for testing for violations of M and IIO. A Gibbs sampling scheme is used for estimating the model parameters. It is shown that the deviance information criterion can be used as an overall test of M and IIO, while posterior predictive checks can be used to test these assumptions at the item level. A real data application illustrates a model-fitting strategy for detecting items that violate M and IIO.     

Evaluative Conditioning: Arti-fact or -fiction?-A Reply to Baeyens, De Houwer, Vansteenwegen, and Eelen (1998)

Baeyenset al.(1998) claim that Field and Davey's (1997) controversial study of conceptual conditioning offers little threat to current conceptions of evaluative conditioning. This article addresses some of the questions posed by Baeyenset al.First, some criticisms of the conceptual conditioning study appear to be based on a misunderstanding of the procedure. Second, we address the issues surrounding the so-called Type-X procedure. Specifically, we begin by reviewing the status of studies that have used a procedure different from the Type-X procedure. It is then argued that, although the Type-X procedure has been used in only a portion of EC research, it has been used primarily in those studies whose outcome has been used to argue that evaluative conditioning (EC) is functionally distinct from autonomic conditioning. We then review the evidence from non-Type-X procedures that EC is a distinct form of learning. Finally, an attempt is made to explain why between-subject controls should be used as a matter of course in this field of research.     

Familiar idiom comprehension

Sentences containing idioms used either literally or figuratively were presented repeatedly for 100 msec per presentation. Half of the sentences were preceded by a paragraph. The number of presentations required to read the sentences and cued recall of the sentences were recorded. The serial brief presentations method provided predictable and meaningful results. Sentences containing idioms used literally required more presentations than those containing idioms used figuratively. Cued recall was better for idioms used literally than for those used figuratively. These results are interpreted as support for the Idiomatic Processing Model of idiom comprehension, which suggests that the figurative meaning is processed first; only if that one is inappropriate is the literal meaning processed.     

Visual selection mediated by location: Selecting successive visual objects

In these experiments, each stimulus consists of a series of frames, each containing a target digit of one color and a distractor digit of another color. The task is to name the highest digit of the target color. Subjects make fewer errors when successive targets appear at the same location than when they appear at different locations, apparently because they select target objects by using a mechanism that is based on location. When successive targets appear at the same location, there is no need to “move” the selection mechanism to a new location, leaving more time to identify the stimuli. These experiments show that location-based selection is used even though selection by color would be more direct. They also demonstrate a method of measuring location-based selection that can be applied to a variety of visual tasks. Further experiments reveal that although location-based selection is used to identify a digit in the presence of a digit distractor, it is not used to identify a digit in the presence of a letter distractor, suggesting that this selection mechanism is not used in this situation to prevent interference among the basic features making up letters and digits, but to inhibit responses associated with the distractors.     

Confirmatory Factor Analyses of Scores From Full and Short Versions of the Marlowe–Crowne Social Desirability Scale

Self-report measures are much used in social psychology. However, such measures are susceptible to response bias. The 33-item Marlowe–Crowne Social Desirability scale (Crowne & Marlowe, 1960) is widely used to detect social desirability in responding. This study used confirmatory factor analyses and item and scale analyses to evaluate different, time-saving, short versions of the scale. The results from 633 management undergraduates showed that all the short versions and the 2-factor model are a significant improvement in fit over the full scale. There were no gender differences on the 14 measures. It is recommended that when the full scale is used, the separate attribution and denial scores are also used. Researchers who decide to use a short version should seriously consider Ballard's (1992) Scale 1 or composite versions because the present study identified these as the best short versions.     

Errors of the standard in the horizontal-vertical illusion

Three experiments were conducted to test the claim that the magnitude of the horizontal-vertical illusion in an L figure varies as a function of which component is used as standard. No difference was found in Experiment 1, in which a staircase procedure was used to establish the PSE. However, by the use of a method of adjustment, the magnitude of illusion was affected by the component used as standard in Experiment 2. The results of Experiment 3, in which a staircase procedure was used with S in upright and recumbent body postures, confirmed those of Experiment 1. It was concluded that earlier differences associated with the standard were a methodological accompaniment of the psychophysical technique used.     

A cautionary note on the effects of range restriction on predictor intercorrelations

The purpose of this research report is to highlight a unique set of issues that arise when considering the effects of range restriction in the context of estimating predictor intercorrelations. Three approaches are used to illustrate the issue: simulation, a concrete applied example, and a reanalysis of a meta-analysis of ability-interview correlations. The general conclusion is that a predictor intercorrelation can differ dramatically from the population value when both predictors are used in a composite that is used operationally for selection. The compensatory nature of a composite means that low scorers on one predictor can only obtain high scores on the composite if they obtain very high scores on the other predictor; this phenomenon distorts the correlation between the predictors.     

Aphasia in Turkish: speech production in Broca's and Wernicke's patients

Turkish speech production was studied in 7 Broca's and 10 Wernicke's aphasics. Turkish is an agglutinative language, with few free-standing closed-class morphemes. The speech of Broca's patients was not telegraphic; although nonfluent, noun and verb suffixes were used appropriately. The speech of Wernicke's aphasics was fluent, using a wide range of often inappropriate forms. Both groups used appropriate nominal morphology. Broca's patients used a limited set of verb forms in contextually appropriate fashion. Wernicke's patients used a wide range of verb forms, all morphosyntactically correct, but often semantically anomalous. Both groups retained canonical subject-object-verb word order and controlled various types of pragmatically appropriate word order variation. It is proposed that aphasic speech patterns reflect retrieval problems rather than impairment of a portion of the language system.     

Stepwise Latent Class Models for Explaining Group-Level Outcomes Using Discrete Individual-Level Predictors

Explaining group-level outcomes from individual-level predictors requires aggregating the individual-level scores to the group level and correcting the group-level estimates for measurement errors in the aggregated scores. However, for discrete variables it is not clear how to perform the aggregation and correction. It is shown how stepwise latent class analysis can be used to do this. First, a latent class model is estimated in which the scores on a discrete individual-level predictor are used to construct group-level latent classes. Second, this latent class model is used to aggregate the individual-level predictor by assigning the groups to the latent classes. Third, a group-level analysis is performed in which the aggregated measures are related to the remaining group-level variables while correcting for the measurement error in the class assignments. This stepwise approach is introduced in a multilevel mediation model with a single individual-level mediator, and compared to existing methods in a simulation study. We also show how a mediation model with multiple group-level latent variables can be used with multiple individual-level mediators and this model is applied to explain team productivity (group level) as a function of job control (individual level), job satisfaction (individual level), and enriched job design (group level).