A study in the cognition of individuals' identity: solving the problem of singular cognition in object and agent tracking

This article compares the ability to track individuals lacking mental states with the ability to track intentional agents. It explains why reference to individuals raises the problem of explaining how cognitive agents track unique individuals and in what sense reference is based on procedures of perceptual-motor and epistemic tracking. We suggest applying the notion of singular-files from theories in perception and semantics to the problem of tracking intentional agents. In order to elucidate the nature of agent-files, three views of the relation between object- and agent-tracking are distinguished: the Independence, Deflationary and Organism-Dependence Views. The correct view is argued to be the latter, which states that perceptual and epistemic tracking of a unique human organism requires tracking both its spatio-temporal object-properties and its agent-properties.     

How are Strouhal number, drag, and efficiency adjusted in high level underwater monofin-swimming?

Strouhal number (St) corresponds to a wake parameter based on the tail kinematics of swimming animals according to St=A.f/U, where f is the stroke frequency, A is the fin-beat peak-to-peak amplitude, and U is the forward speed. St number is a trade-off between amplitude and frequency that generates a forward velocity. This parameter may therefore be affected by swimming technique, which can be evaluated through active drag (AD) and Froude efficiency (eta(F)). The aim of our study was therefore to (1) investigate the range of AD and eta(F) values for high level monofin-swimmers, (2) explore the range of St numbers, and (3) examine to what extent this latter non-dimensional parameter may affect AD and eta(F). To this end, experiments have been conducted on 12 international level monofin-swimmers. St number, eta(F) (calculated according to the elongated-body theory), and AD (computed with velocity perturbation method) were calculated at the same time for an underwater fin-swimming trial, at maximal speed. Lowest values of St numbers (St=0.34) corresponded to fin-swimmers with highest velocities (R=-.77, p<.05), highest efficiencies (R=-.86, p<.001), and lowest active drag (R=.91, p<.001). On the one hand, AD was increased with vertical motion of the fin (R=.84, p<.001), which increased cross-sectional area (R=.78, p<.05). On the other hand, efficiencies showed a tendency to peak at eta(F)=0.82 in a narrow range of St numbers close to 0.4. This St range corresponded to the upper limit of the 0.25-0.4 range usually claimed for maximum efficiency of marine and flying animals. Such results suggest that increasing efficiency and reducing drag improves performance per se (regardless how these parameters are related with St number).     

Mortality salience and the desire for offspring

Research on terror management theory (TMT) illustrates that following mortality salience (MS) people defend their cultural worldviews and bolster self-esteem to transcend death. Recently, research additionally showed that MS increased self-reports of the number of children desired in Dutch men but not in Dutch women. We conducted three studies to further investigate the role of desire for offspring in terror management. In Study 1, we conceptually replicated previous findings for Germany and found increased desire for offspring following MS in both men and women. Extending prior research Study 2 revealed that following MS not only was the accessibility of death-related thoughts increased, but also the accessibility of thoughts related to offspring. Finally, Study 3 suggested that the MS effect on ingroup bias was eliminated under conditions of offspring salience. Relating these findings to TMT, anticipated or actual offspring is discussed as a buffer against existential anxiety.     

Exploring triangulation in infancy: two contrasted cases

Two contrasted father-mother-infant interactions are observed longitudinally during trilogue play. They illustrate the contribution of recent research to the exploration of triangulation in infancy: namely, the infant's capacity to handle triangular interactions and share her affects with her two parents, and the way that this capacity is recruited in functional versus problematic alliances. It is likely that an infant under stress when interacting with one parent will protest at that parent and also at the other. Such is the case when, for example, the father acts intrusively while playing with his baby. The infant is then driven to avert and turns to the mother. The regulation of this dyadic intrusion-avoidance pattern at family level depends on the family alliance. When coparenting is supportive, the mother validates the infant's bid for help without interfering with the father. Thus, the problematic pattern is contained in the dyad, and the infant's triangular capacities remain in the service of her own developmental goals. But when coparenting is hostile-competitive, the mother ignores the infant's bid or engages with her in a way that interferes with her play with her father. In this case, the infant's triangular capacities are used to relieve the tension between the parents. The importance of tracing family process back to infancy for family therapy is discussed.     

Glucocorticoid sensitivity in humans-interindividual differences and acute stress effects

The hypothalamus pituitary adrenal (HPA)- axis is one of the major output systems of the neuroendocrine stress response. Its major end products, glucocorticoids (GCs), have a plethora of effects throughout the organism, most of which are believed to be protective against disturbances of homeostasis. However, negative effects have also been described under specific conditions of hyper- or hypo(re)activity of the HPA axis. Both beneficial and adverse effects of GCs ultimately depend on the target tissue sensitivity to these steroids. Recent findings suggest that GC sensitivity (a) may vary between different target tissues in the same organism, (b) shows large individual differences and (c) can be acutely changed in times of acute stress. In the present review, data are summarized which show differences in GC sensitivities in patients suffering from diverse somatic and psychiatric diseases, as well as chronically stressed individuals. Furthermore, studies are presented that show a rapid modulation of GC sensitivity in response to exercise or psychosocial stress in healthy adults. The response pattern of acute GC sensitivity modulation seems to be influenced by age and sex hormone status of the individual. While the GC signalling cascade may be subject to modulation at several levels, the pathway for acute modulation of GC sensitivity remains to be elucidated.     

Hypothetical and certain inferences from conditional arguments read in texts

In 3 experiments, affirmative and hypothetical probes were presented after narrative texts containing conditional arguments. According to the data, readers represented modus ponens deductions as certain, except when it was only a weakly necessary cause of a given effect. They represented any logically invalid inferences resulting from affirming the conditional consequent as hypothetical, except when it was the effect of strongly sufficient cause. Accordingly, readers must be processing conditional syntax as an asymmetric constraint. However, the underlying causal knowledge can be sufficient either to discredit or warrant the inferences. Thus according to the theory of natural logic, readers can draw formal deductions and be convinced of their necessity. This provides further evidence that readers can represent their inferences as hypothetical (N. Campion, 2004).     

On the control of visual spatial attention: evidence from human electrophysiology

We used electrophysiological methods to track the deployment of visual spatial attention while observers were engaged in concurrent central attentional processing, using a variant of the attentional blink paradigm. Two visual targets (T₁, T₂) were presented at a stimulus onset asynchrony of either 200 ms or 800 ms. T₁ was a white digit among white letters presented on a dark background using rapid serial visual presentation at fixation. T₂ was another digit that was presented to the left or right of fixation simultaneously with a distractor digit in the opposite visual field, each followed by a pattern mask. In each T₂ display, one digit was red and one was green. Half of the subjects reported the red digit and ignored the green one, whereas the other half reported the green digit and ignored the red one. T₁ and T₂ were reported in one block of trials, and only T₂ in another block (order counterbalanced across subjects). Accuracy of report of T₂ was lower at short SOA than at long SOA when both T₁ and T₂ were reported, but was similar across SOA when only T₂ was reported. The electrophysiological results focused on the N2pc component, which was used as an index of the locus of spatial attention. N2pc was reduced in amplitude when subjects reported T₁, and particularly so at the short SOA. The results suggest that attention to T₁ interfered with the deployment of visual spatial attention to T₂.     

The effect of long-term working memory through personalization applied to free recall: Uncurbing the primacy-effect enthusiasm

In this study, a personalization method (Guida, Tardieu, & Nicolas, European Journal of Cognitive Psychology, 21: 862–896 2009) was applied to a free-recall task. Fifteen pairs of words, composed of an object and a location, were presented to 93 participants, who had to mentally associate each pair and subsequently recall the objects. A 30-s delay was introduced on half of the trials, the presentation rate was manipulated (5 or 10 s per item), and verbal and visuospatial working memory tests were administered to test for their effects on the serial curve. Two groups were constituted: a personalized group, for whom the locations were well-known places on their university campus, and a nonpersonalized group, for whom the locations did not refer to known places. Since personalization putatively operationalizes long-term working memory (Ericsson & Kintsch, Psychological Review, 102: 211–245 1995)—namely, the capacity to store information reliably and rapidly in long-term memory—and if we take a dual-store approach to memory, the personalization advantage would be expected to be greater for pre-recency than for recency items. Overall, the results were compatible with long-term working memory theory. They contribute to validating the personalization method as a methodology to characterize the contribution of long-term memory storage to performance in working memory tasks.