The what–where trade-off in multiple-identity tracking

Observers are poor at reporting the identities of objects that they have successfully tracked (Pylyshyn, Visual Cognition, 11, 801-822, 2004; Scholl & Pylyshyn, Cognitive Psychology, 38, 259-290, 1999). Consequently, it has been claimed that objects are tracked in a manner that does not encode their identities (Pylyshyn, 2004). Here, we present evidence that disputes this claim. In a series of experiments, we show that attempting to track the identities of objects can decrease an observer's ability to track the objects' locations. This indicates that the mechanisms that track, respectively, the locations and identities of objects draw upon a common resource. Furthermore, we show that this common resource can be voluntarily distributed between the two mechanisms. This is clear evidence that the location- and identity-tracking mechanisms are not entirely dissociable.     

The cost–benefit trade-off in young children's overimitation behaviour

In overimitation, an observer reproduces a model's visually causally redundant actions in pursuit of an object-directed outcome. There remains an assumption that costs involved in adopting redundant actions renders them maladaptive in the immediate context. Here, we report on an experiment designed to evaluate whether or not overimitating is costly in this way. One hundred and eight children from two contrasting cultural groups (Australian Western vs. South African Bushman) observed an adult open an apparatus using a process that locked one side and opened another. Two toys were then inserted in the locked side and one in the open side. Copying the model meant access only to the lower quantity reward would be possible. This process was repeated for a second trial. Contrary to expectation, children retrieved similar numbers of toys regardless of whether they reproduced the model's actions or not, suggesting that in contexts like that presented here, overimitation is not costly in the ways commonly assumed.     

Multiple-object tracking in children: The “Catch the Spies” task

Multiple-object tracking involves simultaneously tracking positions of a number of target-items as they move among distractors. The standard version of the task poses special challenges for children, demanding extended concentration and the ability to distinguish targets from identical-looking distractors, and may thus underestimate children's tracking abilities. As a result, a modified version of the task called “Catch the Spies” was developed. Participants tracked one to four moving “spies” (targets) that had “disguised” themselves so that they could blend in with a crowd of 10 people (happy-faces). Tracking accuracy was measured in five age groups (6, 8, 10, 12, and 19 years old). All performed well above chance though there were age-related increases in the number that could be tracked at once. Overall, when the effects of age were statistically controlled, tracking performance was significantly better for action videogame players than non-players, and marginally better for action-sports participants than non-participants.     

Decomposition: to what extent? The case of Turkish.

It has been proposed that in agglutinative languages, lexical access of morphologically complex words must involve decomposition rather than full listing (Frauenfelder & Schreuder, 1992; Hankamer, 1989). We tested this proposal in Turkish using a simple lexical decision task. Results show that multimorphemic words that consist of frequent affixes are processed as fast as monomorphemic words. This finding suggests that in languages with rich morphology, not all multimorphemic words are accessed in a decomposed form. To the extent that morphemes are in frequent use, they may induce whole-word rather than decompositional lexical access.     

Eye movements during multiple object tracking: where do participants look?

Similar to the eye movements you might make when viewing a sports game, this experiment investigated where participants tend to look while keeping track of multiple objects. While eye movements were recorded, participants tracked either 1 or 3 of 8 red dots that moved randomly within a square box on a black background. Results indicated that participants fixated closer to targets more often than to distractors. However, on 3-target trials, fixation was closer to the center of the triangle formed by the targets more often than to any individual targets. This center-looking strategy seemed to reflect that people were grouping the targets into a single object rather than simultaneously minimizing all target eccentricities. Here we find that observers deliberately focus their eyes on a location that is different from the objects they are attending, perhaps as a consequence of representing those objects as a group.     

Development: Compared to what?: Contrast effects in age-comparative paradigms

Recent controversies about judgment competence of preschool and adolescent children are considered as being a possible product of contrast effects. That is, perceived abilities of children of a given age group may depend on the ages of the other subjects in the experiment. An experiment was done to test the possibility of contrast effects in age-comparative experiments. One group of subjects read about three experimental tasks in which 6-year-old children performed better than 4-year-olds. A second group read about 6-year-olds performing worse than 8-year-olds on the same tasks. Performance levels of 6-year-olds were the same on the two forms. For each task subjects rated the competence of each of the two age groups on the task and predicted the performance of the two groups on a related task. Undergraduate subjects' competence ratings and predictions were higher for 6-year-olds when compared to 4-year-olds than when compared to 8-year-olds. Psychology graduate students showed the same contrast effect for predictions but not for competence ratings. The results are discussed in terms of potential biases in age-comparative methods in developmental psychology.     

The property of rationality: a guide to what rationality requires?

Can we employ the property of rationality in establishing what rationality requires? According to a central and formal thesis of John Broome’s work on rational requirements, the answer is ‘no’—at least if we expect a precise answer. In particular, Broome argues that (i) the property of full rationality (i.e. whether or not you are fully rational) is independent of whether we formulate conditional requirements of rationality as having a wide or a narrow logical scope. That is, (ii) by replacing a wide-scope requirement with a corresponding narrow-scope requirement (or vice versa), we do not alter the situations in which a person is fully rational. As a consequence, (iii) the property of full rationality is unable to guide us in determining whether a rational requirement has a wide or a narrow logical scope. We cannot resolve the wide/narrow scope debate by appealing to a theory of fully rational attitudes. This paper argues that (i), (ii) and (iii) are incorrect. Replacing a wide- with a corresponding narrow-scope requirement (or vice versa) can alter the set of circumstances in which a person is fully rational. The property of full rationality is therefore not independent of whether we formulate conditional requirements of rationality as having a wide or a narrow logical scope. As a consequence, the property of full rationality can guide us in determining what rationality requires—even in cases where we expect a precise answer.     

The altruistic personality: in what contexts is it apparent?

Hypotheses concerning the specific contexts in which an altruistic personality might be most apparent were investigated. College students completed questionnaires tapping components of an altruistic personality, emotionality, and social desirability. At a 2nd session, the emotional evocativeness and ease of escape from the helping situation were experimentally manipulated. Ss were exposed to a distressed woman, completed state sympathy and personal distress indexes, and were given an opportunity to assist the woman. High scorers on dispositional altruism were expected to assist most when escape was easy, particularly when the distress cues were obvious. Altruistic and emotionally reactive persons were also expected to help most in a psychologically "weak" environment. Both predictions were supported. The relations between helping and the other predictors were also examined.