Distinct neural mechanisms mediate olfactory memory formation at different timescales

Habituation is one of the oldest forms of learning, broadly expressed across sensory systems and taxa. Here, we demonstrate that olfactory habituation induced at different timescales (comprising different odor exposure and intertrial interval durations) is mediated by different neural mechanisms. First, the persistence of habituation memory is greater when mice are habituated on longer timescales. Second, the specificity of the memory (degree of cross-habituation to similar stimuli) also depends on induction timescale. Third, we demonstrate a pharmacological double dissociation between the glutamatergic mechanisms underlying short- and long-timescale odor habituation. LY341495, a class II/III metabotropic glutamate receptor antagonist, blocked habituation only when the induction timescale was short. Conversely, MK-801, an N-methyl-D-aspartate (NMDA) receptor antagonist, prevented habituation only when the timescale was long. Finally, whereas short-timescale odor habituation is mediated within the anterior piriform cortex, infusion of MK-801 into the olfactory bulbs prevented odor habituation only at longer timescales. Thus, we demonstrate two neural mechanisms underlying simple olfactory learning, distinguished by their persistence and specificity, mediated by different olfactory structures and pharmacological effectors, and differentially utilized based solely on the timescale of odor presentation.     

Internet message boards for suicidal people: a typology of users.

Clinical psychological discourse contains a varied array of evaluations of the risks and/or benefits of Internet message boards where people can discuss their suicidal thoughts. Public opinion contends they are harmful. To assess this assumption, an online questionnaire (N = 164) survey was conducted on a German message board for suicidal people. Three user types were identified with differing motives for visiting the forum and different usage effects of the message board. The results contradict the assumptions that suicide message boards are generally a source of potential harm and that they foster suicidal tendencies and point instead to their predominantly constructive or even suicide-preventive functions.     

Frames of reference in social cognition

How is mindreading affected by social context? It is often implicitly assumed that there is one single way to understand others, whatever the situation or the identity of the person. In contrast, I emphasize the duality of functions of mindreading depending on the context (social interaction and social observation), as well as the duality of social frames of reference (egocentric and allocentric). I argue in favour of a functional distinction between knowledge-oriented mindreading and interaction-oriented mindreading. They both aim at understanding other people's behaviour. But they do so using different strategies. However, to say that mindreading has two functions does not suffice to show that there are two kinds of mindreading. One and the same ability could accomplish different functions. Unfortunately, there has been almost no experimental data on a possible dissociation between two kinds of mindreading abilities. Nonetheless, I discuss a few results that point towards a dual ability.     

The Montreal Affective Voices: A validated set of nonverbal affect bursts for research on auditory affective processing

The Montreal Affective Voices consist of 90 nonverbal affect bursts corresponding to the emotions of anger, disgust, fear, pain, sadness, surprise, happiness, and pleasure (plus a neutral expression), recorded by 10 different actors (5 of them male and 5 female). Ratings of valence, arousal, and intensity for eight emotions were collected for each vocalization from 30 participants. Analyses revealed high recognition accuracies for most of the emotional categories (mean of 68%). They also revealed significant effects of both the actors' and the participants' gender: The highest hit rates (75%) were obtained for female participants rating female vocalizations, and the lowest hit rates (60%) for male participants rating male vocalizations. Interestingly, the mixed situations--that is, male participants rating female vocalizations or female participants rating male vocalizations--yielded similar, intermediate ratings. The Montreal Affective Voices are available for download at vnl.psy.gla.ac.uk/ (Resources section).     

The co-consciousness hypothesis

Phenomenology and the Cognitive Sciences - Self-knowledge seems to be radically different from the knowledge of other people. However, rather than focusing on the gap between self and others, we...     

Prediction of Needle Sharing Among Injection Drug Users1

The aim of the present study was to identify the psychosocial factors associated with the intention and behavior of not sharing used needles and syringes among 459 intravenous drug users (IDUs). The intention to not share used needles was positively associated with personal normative beliefs and self‐efficacy; it was negatively related to the proportion of injections with lending used needles and borrowing syringes from sexual partners. Borrowing used needles was negatively associated with intention whereas loaning syringes was positively related to a negative HIV test result. These results suggest that it is only when a direct personal exposure to HIV infection is possible (borrowing) that intention not to borrow is highlighted. Moreover, being HIV positive appears to reduce loaning used syringes.     

Attentional and anatomical considerations for the representation of simple stimuli in visual short-term memory: evidence from human electrophysiology

Observers encoded the spatial arrangement of two or three horizontal line segments relative to a square frame presented for 150 ms either in left or right visual field and either above or below the horizontal midline. The target pattern was selected on the basis of colour (red vs. green) from an equivalent distractor pattern in the opposite left–right visual hemifield. After a retention interval of 450 or 650 ms a test pattern was presented at fixation. The task was to decide whether the test was the same as the encoded pattern or different. Selection of the to-be-memorised pattern produced an N2pc response that was not influenced by the number of line segments nor by the length of the retention interval, but that was smaller in amplitude for patterns presented in the upper visual field compared with patterns presented in the lower visual field. A sustained posterior contralateral negativity (SPCN) followed the N2pc. The SPCN was larger for patterns with three line segments than for two, was larger for patterns encoded from lower visual field than from upper visual field, and returned to baseline sooner for the shorter retention interval than for the longer interval. These results, and others, provide an interesting and complex pattern of similarities and differences between the N2pc and SPCN, consistent with the view that N2pc reflects mechanisms of attentional selection whereas the SPCN reflects maintenance in visual short-term memory.     

Kasuistik zur Kindeswohlgefährdung bei postpartaler Depression

Postpartum psychiatric disorders adversely affect the relationship between the mother and her baby, frequently in a very serious way. It is common that both objective and subjective aspects of this relationship would be negatively influenced by the maternal pathology. The disturbances that arise from the psychiatric disorders could become a hostile and rejecting quality and could be unfavourable to the long-term development of the child. Obsessional impulses to harm the baby are not rare by mothers in the postpartum period. A large figure of severely depressed and psychotic mothers admited to have had some thoughts of harming or to killing the baby. Some of them have already done harmful things to their babies. Ideations of infanticide or child abuse are not always associated with psychiatric disorders (i.e. depressive symptoms or delusion). They could be a consequence of a severe Bonding disorder.     

Soziales Training im Jugendstrafvollzug: Effekte auf Sozial- und Legalbewährung

Social competence is viewed as a decisive protective factor in avoiding delinquent behaviour. The encouragement of social competence is therefore an essential content of juvenile offender treatment. The central issue this paper addresses is whether the participation in social competence trainings in youth correctional facilities prevents recidivism and is conductive to social reintegration after release. This study uses longitudinal data of 218 males aged 15 to 24 years in youth correctional facilities. A control group was established by Propensity Score Matching which was compared with 109 former participants of social competence training. The results of the analyses put the relevancy of the social competence training for the future life of the juveniles in perspective.     

Interpersonal violence and its relationship to some personality measures

One hundred and fifteen patients in a psychiatric hospital for criminal offenders volunteered to be tested with the overcontrolled hostility scale, the self focus sentence completion, and an emotional empathy measure. The subjects were divided into five groups on the basis of criminal offenses (murder, assault with a deadly weapon, rape, pedophilia, and nonviolent property offenses). It was also possible to divide the sample on the basis of diagnostic features (psychosis, personality disorder, and brain syndrome). The results failed to support the hypothesis that more violent (by nature of their offense) individuals would-as a group-score higher on the overcontrolled hostility scale than less aggressive counterparts. There was some evidence that psychotics showed more self focus at the expense of external focus. The empathy measure failed to reveal any meaningful differences. It is suggested that more validation data are called for to establish the generality of the overcontrolled hostility scale and that, in view of the therapeutic importance which empathy training may have for violent individuals, further effort should be expanded to find a generally valid empathy measure.