Objective assessment of the functional role of spike train correlations using information measures

The functional role of correlations between neuronal spike trains remains strongly debated. This debate partly stems from the lack of a standardized analysis technique capable of accurately quantifying the role of correlations in stimulus encoding. We believe that information theoretic measures may represent an objective method for analysing the functional role of neuronal correlations. Here we show that information analysis of pairs of spike trains allows the information content present in the firing rate to be disambiguated from any extra information that may be present in the temporal relationships of the two spike trains. We validate and illustrate the method by applying it to simulated data with variable degrees of known synchrony, and by applying it to recordings from pairs of sites in the primary visual cortex of anaesthetized cats. We discuss the importance of information theoretic analysis in elucidating the neuronal mechanisms underlying object identification.     

Rank order in pairs of communally nursing female mice (Mus musculus domesticus) and Maternal Aggression Towards Conspecific Intruders of Differing Sex

This study examined social behavior between pairs of unfamiliar lactating females, with litters of the same age, at different periods after parturition (3, 7, and 17 days). Tests were generally followed by the formation of communal rearing nests, and subsequent maternal attack on intruders of differing sex was assessed. In all three intervals lactating females showed ritualized attack with formation of clear dominance-subordination relationships before combining litters into communal nests. The dominant females in 90% of cases started to retrieve alien pups into their nests. Agonistic behavior and communal nest formation were most rapid when pups were around 3 days old. Maternal attack on conspecific intruders was mainly displayed by the dominant lactating females. Male and female intruders were equally attacked (in terms of frequency and intensity of attack), but there was less such aggression when pups were around 17 days of age. Nevertheless the topography of biting attack employed against female and male conspecific intruders was different. Females were attacked using a strategy avoiding bites to the head and ventral surface (indicative of “offensive” behavior) whereas males were severely bitten on vulnerable body regions (indicative of “defensive” behavior).     

The attribution of intentionality: the role of skill and morality

The present study contributes to the discussion on the different components which constitute the intentionality concept about an undesired side effect, focusing on the morality and the skill. Two hundred and forty participants were asked to read a brief story about a car accident, in which it was explained the motivation of the high speed and objective and subjective skill of the agent to drive the car, and to fill in six questions about intentionality, objective risk, mental representation of risk, risk acceptance and blameworthiness for the outcome. The principal results showed that when the motivation is morally negative, people judge the side effect more intentional, also because they make more severe judgments about risk and blameworthiness. Moreover, when people are objectively proficient to perform the action (objective skill) the side effect is considered less risky and intentional and, in the case of a negative outcome, they are judged less severely than if they have a poor ability. Finally, a self-assessment of low skill to make the action (subjective skill) leads people to assess higher risks and, consequently, more intentionality for the side effect. The results are discussed on the basis of the literature about some specific components that make up the intentionality concept.