Persons,animals, and identity

The paper is concerned with how neo-Lockean accounts of personal identity should respond to the challenge of animalist accounts. Neo-Lockean accounts that hold that persons can change bodies via brain transplants or cerebrum transplants are committed to the prima facie counterintuitive denial that a person is an (biologically individuated) animal. This counterintuitiveness can be defused by holding that a person is biological animal (on neo-Lockean views) if the “is” is the “is” of constitution rather than the “is” of identity, and that a person is identical with an animal in a sense of “animal” different from that which requires the persistence conditions of animals to be biological. Another challenge is the “too many minds problem”: if persons and their coincident biological animals share the same physical properties, and mental properties supervene on physical properties, the biological animal will share the mental properties of the person, and so should itself be a person. The response to this invokes a distinction between “thin” properties, which are shared by coincident entities, and “thick” properties which are not so shared. Mental properties, and their physical realizers, are thick, not thin, so are not properties persons share with their bodies or biological animals. The paper rebuts the objection that neo-Lockean accounts cannot explain how persons can have physical properties. To meet a further problem it is argued that the biological properties of persons and those of biological animals are different because of differences in their causal profiles.     

Retraction and Revocation in Agent Deliberation Dialogs

We present a generic denotational semantic framework for protocols for dialogs between rational and autonomous agents over action which allows for retraction and revocation of proposals for action. The semantic framework views participants in a deliberation dialog as jointly and incrementally manipulating the contents of shared spaces of action-intention tokens. The framework extends prior work by decoupling the identity of an agent who first articulates a proposal for action from the identity of any agent then empowered to retract or revoke the proposal, thereby permitting proposals, entreaties, commands, promises, etc., to be distinguished semantically.     

The relative importance of spatial versus temporal structure in the perception of biological motion: an event-related potential study

We investigated how the spatiotemporal structure of animations of biological motion (BM) affects brain activity. We measured event-related potentials (ERPs) during the perception of BM under four conditions: normal spatial and temporal structure; scrambled spatial and normal temporal structure; normal spatial and scrambled temporal structure; and scrambled spatial and temporal structure. As in a previous study, we identified two negative components at both occipitotemporal regions: N210 reflected general motion processing while N280 reflected the processing of BM. We analyzed the averaged ERPs in the 200-300 ms response time window and found that spatial structure had a substantial effect on the magnitude of the averaged response amplitude in both hemispheres. This finding suggests that spatial structure of point-lights elicits a stronger response in the occipitotemporal region than temporal structure for the BM perception.     

Experimental control of nodality via equal presentations of conditional discriminations in different equivalence protocols under speed and no-speed conditions

A within-participant comparison of simple-to-complex, complex-to-simple, and simultaneous protocols was conducted establishing different sets of three 7-member equivalence classes for 4 undergraduate students. The protocols were implemented under either accuracy-only or accuracy-plus-speed conditions while keeping number of presentations of training and testing trials equal. The results partially support previous reports of differential effects on acquisition, with participants completing more blocks in training under the simultaneous than the complex-to-simple and the simple-to-complex protocols. Across the protocols, however, the number of trials completed to criterion did not vary systematically. More important, response speed and accuracy did not decrease as a function of nodal number, with or without the speed contingency, or under any protocol. The latter results challenge the generality of previous reports of the nodality effect and the notion of "relatedness" of equivalence-class members, and support a reinforcement-contingency, instead of a structural, perspective on equivalence-class formation.     

Attraction and social coordination: mutual entrainment of vocal activity rhythms

To investigate factors that affect the mutual entrainment of vocal activity rhythms, female general psychology students paired according to attitude similarity questionnaires engaged in 40-minute introductory conversations. Fourier analyses performed on speakers' on-off vocal activity demonstrated periodic oscillations in talkativeness. Although some dyads coordinated their vocal activity rhythms, speech accommodation was not predicted by attitude similarity or attraction and did not affect ratings of conversation quality. These rhythms of dialogue appear resistant to change, their behavioral momentum rooted perhaps in an underlying chronobiology.     

Acute nicotine withdrawal symptoms and anxious responding to bodily sensations: a test of incremental predictive validity among young adult regular smokers

Although previous work has found associations between panic and smoking, little research has investigated potential mechanisms by which smoking may contribute to panic problems. The present investigation evaluated the incremental validity of acute nicotine withdrawal symptoms (elicited by an average of 2 h of nicotine deprivation) relative to negative affectivity, anxiety sensitivity, and nicotine dependence in predicting anxiety responding to 3-min voluntary hyperventilation. The sample consisted of 90 regular smokers (46 females), as defined by smoking 10 cigarettes per day for at least 1 year, recruited through the general community. Consistent with prediction, greater levels of pre-challenge nicotine withdrawal symptoms uniquely predicted post-challenge intensity of panic symptoms and anxiety relative to other established factors. Findings are discussed in the context of how regular smoking may promote panic symptomotology.     

Local and global aspects of biological motion perception in children born at very low birth weight

Biological motion perception can be assessed using a variety of tasks. In the present study, 8- to 11-year-old children born prematurely at very low birth weight (<1500 g) and matched, full-term controls completed tasks that required the extraction of local motion cues, the ability to perceptually group these cues to extract information about body structure, and the ability to carry out higher order processes required for action recognition and person identification. Preterm children exhibited difficulties in all 4 aspects of biological motion perception. However, intercorrelations between test scores were weak in both full-term and preterm children—a finding that supports the view that these processes are relatively independent. Preterm children also displayed more autistic-like traits than full-term peers. In preterm (but not full-term) children, these traits were negatively correlated with performance in the task requiring structure-from-motion processing, r(30) = ?.36, p < .05), but positively correlated with the ability to extract identity, r(30) = .45, p < .05). These findings extend previous reports of vulnerability in systems involved in processing dynamic cues in preterm children and suggest that a core deficit in social perception/cognition may contribute to the development of the social and behavioral difficulties even in members of this population who are functioning within the normal range intellectually. The results could inform the development of screening, diagnostic, and intervention tools.     

Mother and infant coordinate heart rhythms through episodes of interaction synchrony

Animal studies demonstrated the powerful impact of maternal-infant social contact on the infant's physiological systems, yet the online effects of social interactions on the human infant's physiology remain poorly understood. Mothers and their 3-month old infants were observed during face-to-face interactions while cardiac output was collected from mother and child. Micro-analysis of the partners’ behavior marked episodes of gaze, affect, and vocal synchrony. Time-series analysis showed that mother and infant coordinate heart rhythms within lags of less than 1 s. Bootstrapping analysis indicated that the concordance between maternal and infant biological rhythms increased significantly during episodes of affect and vocal synchrony compared to non-synchronous moments. Humans, like other mammals, can impact the physiological processes of the attachment partner through the coordination of visuo-affective social signals.