The role of memory and restricted context in repeated visual search

Previous studies have shown that the efficiency of visual search does not improve when participants search through the same unchanging display for hundreds of trials (repeated search), even though the participants have a clear memory of the search display. In this article, we ask two important questions. First, why do participants not use memory to help search the repeated display? Second, can context be introduced so that participants are able to guide their attention to the relevant repeated items? Experiments 1-4 show that participants choose not to use a memory strategy because, under these conditions, repeated memory search is actually less efficient than repeated visual search, even though the latter task is in itself relatively inefficient. However, when the visual search task is given context, so that only a subset of the items are ever pertinent, participants can learn to restrict their attention to the relevant stimuli (Experiments 5 and 6).     

The perfect murder: A philosophical whodunit

In his Reasons and Persons, Derek Parfit argues from the possibility of cases of fission and/or fusion of persons that one must reject identity as what matters for personal survival. Instead Parfit concludes that what matters is “psychological connectedness and/or continuity with the right kind of cause,” or what he calls an R-relation. In this paper, I argue that, if one accepts Parfit’s conclusion, one must accept that R-relations are what matter for moral responsibility as well. Unfortunately, it seems that accepting that the R-relation is what matters for both survival and moral responsibility leads to a contradiction. My goal, however, is not merely to point out a problem in Parfit’s account. Instead, I believe that once we understand the basic intuitions which lead to this contradiction, it is clear that there is no fully satisfactory way to account for what matters with respect to survival and moral responsibility.     

Can Models of God Compete?

Though the very task of modeling God implies that the reality of God is to some degree unknowable, there are a variety of positions one may take concerning the degree to which one has epistemic access to God. If our models of God are too influenced by subjectivity, it makes no sense to test them against each other in rational competition. In this essay, I define four possible positions that may underlie the task of God-modeling: mysteriosophy, theopoetics, critical realism, and fallibilism. Of these four, I propose that fallibilism is the most appropriate method for constructing models of God. Fallibilism simultaneously assumes that our models are able to refer to a divine reality, and yet always with a tentative stance, as absolute confirmation or universal consensus concerning them will almost certainly never be obtained. Models of God can engage in rational competition, but a final decision will probably be delayed indefinitely. This paper was delivered during the APA Pacific 2007 Mini-Conference on Models of God.     

Speech-associated gestures, Broca’s area, and the human mirror system

Speech-associated gestures are hand and arm movements that not only convey semantic information to listeners but are themselves actions. Broca’s area has been assumed to play an important role both in semantic retrieval or selection (as part of a language comprehension system) and in action recognition (as part of a “mirror” or “observation–execution matching” system). We asked whether the role that Broca’s area plays in processing speech-associated gestures is consistent with the semantic retrieval/selection account (predicting relatively weak interactions between Broca’s area and other cortical areas because the meaningful information that speech-associated gestures convey reduces semantic ambiguity and thus reduces the need for semantic retrieval/selection) or the action recognition account (predicting strong interactions between Broca’s area and other cortical areas because speech-associated gestures are goal-direct actions that are “mirrored”). We compared the functional connectivity of Broca’s area with other cortical areas when participants listened to stories while watching meaningful speech-associated gestures, speech-irrelevant self-grooming hand movements, or no hand movements. A network analysis of neuroimaging data showed that interactions involving Broca’s area and other cortical areas were weakest when spoken language was accompanied by meaningful speech-associated gestures, and strongest when spoken language was accompanied by self-grooming hand movements or by no hand movements at all. Results are discussed with respect to the role that the human mirror system plays in processing speech-associated movements.     

A computational model of fractionated conflict-control mechanisms in task-switching

A feature of human cognition is the ability to monitor and adjust one's own behavior under changing circumstances. A dynamic balance between controlled and rapid responding is needed to adapt to a fluctuating environment. We suggest that cognitive control may include, among other things, two distinct processes. Incongruent stimuli may drive top-down facilitation of task-relevant responses to bias performance toward exploitation vs. exploration. Task or response switches may generally slow responses to bias toward accuracy vs. speed and exploration vs. exploitation. Behavioral results from a task switching study demonstrate these two distinct processes as revealed by higher-order sequential effects. A computational model implements the two conflict-control mechanisms, which allow it to capture many complex and novel sequential effects. Lesion studies with the model demonstrate that the model is unable to capture these effects without the conflict-control loops and show how each monitoring component modulates cognitive control. The results suggest numerous testable predictions regarding the neural substrates of cognitive control.     

Moral personality of brave and caring exemplars

Two contrasting types of moral exemplars were examined so as to identify personality variables associated with moral action. The sample comprised 50 Canadian awardees for either exceptional bravery or caring, as well as 50 comparison participants. Participants responded to a set of personality questionnaires and a life-review interview. Personality variables were found to substantially augment moral cognition in the prediction of exemplary action. In support of the notion that there is a personological core to the moral domain, it was found that moral exemplars were distinguished from the comparison groups by themes embodied in their life narratives. Specifically, moral exemplars had stronger motivational themes of both agency and communion, were more likely to construe critical life events redemptively, more frequently identified helpers in early life, and reported more secure attachments. Furthermore, the personality of caring exemplars was more nurturant, generative, and optimistic than that of brave exemplars; these somewhat divergent personality profiles imply multiple ideals of moral maturity.     

Misunderstanding the affective consequences of everyday social interactions: the hidden benefits of putting one's best face forward

Positive self-presentation may have beneficial consequences for mood that are typically overlooked. Across a series of studies, participants underestimated how good they would feel in situations that required them to put their best face forward. In Studies 1 and 2A, participants underestimated the emotional benefits of interacting with an opposite sex stranger versus the benefits of interacting with a romantic partner. In Study 2B, participants who were instructed to engage in self-presentation felt happier after interacting with their romantic partner than participants who were not given this instruction, although other participants serving as forecasters did not anticipate such benefits. Increasing the generalizability of this self-presentation effect across contexts, the authors demonstrated that participants also underestimated how good they would feel before and after being evaluated by another person (Studies 3 and 4). This failure to recognize the affective benefits of putting one's best face forward may underlie forecasting errors regarding the emotional consequences of the most common forms of social interactions.     

Roles of moral philosophy in appropriated bioethics: a response to Baker and McCullough

Strong arguments support the notion that much of modern bioethics is a result of appropriation rather than strict application of traditional moral philosophy. Nevertheless, it is important to recognize these sources and approaches associated with them, even when working with appropriated theories, since traditional ethical theory does and should influence modern bioethics.