A Contextual Approach to Scientific Understanding

Achieving understanding of nature is one of the aims of science. In this paper we offer an analysis of the nature of scientific understanding that accords with actual scientific practice and accommodates the historical diversity of conceptions of understanding. Its core idea is a general criterion for the intelligibility of scientific theories that is essentially contextual: which theories conform to this criterion depends on contextual factors, and can change in the course of time. Our analysis provides a general account of how understanding is provided by scientific explanations of diverse types. In this way, it reconciles conflicting views of explanatory understanding, such as the causal-mechanical and the unificationist conceptions.     

The Impact of the Big Five Personality Traits on Reports of Child Behavior Problems by Different Informants

The present study compared ratings of a standardized sample of child behavior problems across informants and examined the effects of informant personality traits on child behavior ratings by mothers, teachers, and group-care workers. Participants were 55 clinic-referred children, aged 6–12 years. All informants watched and rated the same 17-min videotaped behavior sample of a familiar target child. Independent trained observers rated the same videotapes to provide criterion ratings. Informants personality traits were assessed using the NEO Five Factor Personality Inventory. Results showed that mothers reported fewer behavior problems than did the professionals, that the informants who were familiar with the child reported more behavior problems than did the independent observers, and that higher levels of informant neuroticism were related to higher ratings of child behavior problems in the case of the professionals, but not in the case of the mothers. In addition, group-care workers who were less extraverted and open were likely to report more child behavior problems than group-care workers with normal levels of extraversion and openness. Finally, no relations were found between agreeableness or conscientiousness and ratings of child behavior. Findings suggest that professionals who work with children are not immune to distortions based on their own personality.     

Mental representation of prepositional compounds: evidence from Italian agrammatic patients

The processing of Prepositional compounds (typical Neo-latin noun--noun modifications where a head noun is modified by a prepositional phrase, e.g., mulino a vento, windmill) was preliminarily studied with a group of six agrammatic aphasic patients, and, in more detail, with a further agrammatic patient (MB). Omission was the most frequent error type in naming, whereas in the other tasks (repetition, reading, writing, and completion) errors were mostly substitutions of the target preposition. This happened even with fully lexicalized compound forms, i.e., those forms where the linking preposition is syntactically and semantically opaque. These findings are interpreted in terms of a dual-route theory of lexical access to morphologically complex words.     

The Ponzo illusion with auditory substitution of vision in sighted and early-blind subjects

We tested the effects of using a prosthesis for substitution of vision with audition (PSVA) on sensitivity to the Ponzo illusion. The effects of visual experience on the susceptibility to this illusion were also assessed. In one experiment, both early-blind and blindfolded sighted volunteers used the PSVA to explore several variants of the Ponzo illusion as well as control stimuli. No effects of the illusion were observed. The results indicate that subjects focused their attention on the two central horizontal bars of the stimuli, without processing the contextual cues that convey perspective in the Ponzo figure. In a second experiment, we required subjects to use the PSVA to consider the two converging oblique lines of the stimuli before comparing the length of the two horizontal bars. Here we were able to observe susceptibility to the Ponzo illusion in the sighted group, but to a lesser extent than in a sighted non-PSVA control group. No clear effect of the ilusion was obtained in early-blind subjects. These results suggest that, at least in sighted subjects, perception obtained with the PSVA shares perceptual processes with vision. Visual experience appears mandatory for a Ponzo illusion to occur with the PSVA.     

Further evidence for the role of inferential reasoning in forward blocking

Previous studies on human causal learning (De Houwer & Beckers, 2003; De Houwer, Beckers, & Glautier, 2002) showed that secondary task difficulty (performing an easy vs. a difficult secondary task during the main causal learning task) and ceiling information (outcome occurs with a maximal vs. submaximal intensity) had an influence on forward blocking (i.e., lower causal ratings for cue T when AT+ trials are preceded by A+ trials than when no A+ trials are presented). We extended these studies by also examining self-reports of participants about the reasons behind their causal ratings. Blocking was found only for participants who reported an appropriate blocking inference. Furthermore, secondary task difficulty and ceiling information influenced the number of participants who reported an appropriate blocking inference. These findings point to a major impact of inferential reasoning in human causal learning.     

What do rats learn about the geometry of object arrays? Tests with exploratory behavior

Six experiments using habituation of exploratory behavior tested whether disoriented rats foraging in a large arena encode the shapes of arrays of objects. Rats did not respond to changes in position of a single object, but they responded to a change in object color and to a change in position of 1 object in a square array, as in previous research (e.g., C. Thinus-Blanc et al., 1987). Rats also responded to an expansion of a square array, suggesting that they encoded sets of interobject distances rather than overall shape. In Experiments 4-6, rats did not respond to changes in sense of a triangular array that maintained interobject distances and angles. Shapes of object arrays are encoded differently from shapes of enclosures.     

Cultural Differences in Belief Bias Associated with Deductive Reasoning?

Norenzayan, Smith, Jun Kim, and Nisbett (2002) investigated cultural differences in the use of intuitive versus formal reasoning in 4 experiments. Our comment concerns the 4th experiment where Norenzayan et al. reported that, although there were no cultural differences in accuracy on abstract logical arguments, Koreans made more errors than U.S. undergraduates in judging the logical validity of concrete arguments. Norenzayan et al. concluded that Koreans are less likely than European Americans to decontextualize an argument's content from its logical structure, as Koreans were more likely to consider the believability of the conclusion when assessing an argument's validity (a belief bias). Notably, Korean participants were more conservative (less likely to say an argument is valid) than European American participants when assessing arguments. An analysis of the average of the hit and correct rejection rates in each of the conditions (abstract, concrete–believable, concrete–nonbelievable) revealed that, contrary to conclusions of Norenzayan et al., European Americans were no better than Koreans at determining the validity of concrete deductive arguments with conclusions varying in believability.