Harm should not be a necessary criterion for mental disorder: some reflections on the DSM-5 definition of mental disorder

Theoretical Medicine and Bioethics - The general definition of mental disorder stated in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders seems to identify a mental...     

Footshock intensity and generalization in contextual and auditory-cued fear conditioning in the rat

The relationship between US (footshock) intensity and the two conditioned freezing responses (to acoustic CS and to "context") was investigated in fear conditioning. Administered footshock intensity was 0.00, 0.15, 0.30, 0.60, 0.90, and 1.20 mA to six different groups of 70-day-old male Albino Wistar rats. To measure contextual freezing, the animals were again placed inside the conditioning apparatus without acoustic CS and US presentation. To measure acoustic CS freezing, the animals were placed in a totally different apparatus and only the acoustic CS was presented. The 0.15 mA footshock intensity was not sufficient to condition the animals, in fact no freezing was exhibited as in the non-shocked control group. The 0.30 mA footshock intensity was sufficient only to condition the animals to the acoustic CS, whereas the 0.60 mA was sufficient to condition the animals both to acoustic CS and to context. Footshock intensities (0.90 and 1.20 mA) did not elicit any significant increase in conditioned freezing for either acoustic CS or context but at the highest one the generalization phenomenon appeared (freezing in the different context before presentation of acoustic CS). Acoustic CS freezing to all over-threshold intensities was longer than that to context. In conclusion, freezing responses to acoustic CS and context after increasing footshock intensities follow distinct patterns, and intermediate footshock intensities (0.60 and 0.90 mA) appear to be the most useful for eliciting conditioned freezing responses to acoustic CS and to context without inducing a generalized fear status contamination.     

Toleration as the Balance Between Liberty and Security

The Journal of Ethics - Traditionally, an adequate strategy to deal with the tension between liberty and security has been toleration, for the latter allows the maximization of individual liberty...     

Identity dynamics in adolescence: Processes,antecedents, and consequences*

Abstract

Identity formation is the core developmental task of adolescence. The three-factor identity model provides a parsimonious framework for unraveling the dynamic process by which youth form and revise their identity over time. In this article, studies conducted with the three-factor model are reviewed, showing how they can provide new insights to address three main questions: (a) How do adolescents develop their identity? (b) How is adolescent identity related to well-being and psychosocial functioning? (c) How does the cultural context in which adolescents come of age influence this process? Importantly, the extent to which adolescents are successful in forming and maintaining a stable identity is influenced by the context in which they live, and is strongly intertwined with their psychosocial functioning.     

The Interplay of Self‐Certainty and Prosocial Development in the Transition from Late Adolescence to Emerging Adulthood

The transition from late adolescence to emerging adulthood is a period of the life span that offers young people the possibility to consolidate their self‐certainty and prosociality. Both aspects are of core importance for increasing personal and societal well‐being. The purpose of this longitudinal study was twofold: (i) to examine patterns of change and stability in self‐concept clarity and prosociality; and (ii) to unravel over time associations between these constructs in the transition from late adolescence to emerging adulthood. In addressing both aims, we explored the moderating effects of gender. Participants were 244 Dutch emerging adults (46% male; mean age at T1 = 16.73 years) who completed six waves of data collection (mean age at T6 = 22.7 years). Findings highlighted that (i) self‐concept clarity developed nonlinearly, with an initial decline from T1 to T2 followed by an increase thereafter, while prosociality increased linearly over time and both self‐concept clarity and prosociality were characterized by high rank‐order consistency; (ii) self‐concept clarity and prosociality were positively related over time, with the effect of prosociality on self‐concept clarity being stronger than the reciprocal effect of self‐concept clarity on prosociality. Gender differences were detected in mean levels of self‐concept clarity and prosociality (male participants reported higher self‐concept clarity and lower prosociality than female participants) but not in their developmental pathways nor in their reciprocal associations. Copyright © 2016 European Association of Personality Psychology     

Multisensory-mediated auditory localization

Multisensory integration is a powerful mechanism for maximizing sensitivity to sensory events. We examined its effects on auditory localization in healthy human subjects. The specific objective was to test whether the relative intensity and location of a seemingly irrelevant visual stimulus would influence auditory localization in accordance with the inverse effectiveness and spatial rules of multisensory integration that have been developed from neurophysiological studies with animals [Stein and Meredith, 1993 The Merging of the Senses (Cambridge, MA: MIT Press)]. Subjects were asked to localize a sound in one condition in which a neutral visual stimulus was either above threshold (supra-threshold) or at threshold. In both cases the spatial disparity of the visual and auditory stimuli was systematically varied. The results reveal that stimulus salience is a critical factor in determining the effect of a neutral visual cue on auditory localization. Visual bias and, hence, perceptual translocation of the auditory stimulus appeared when the visual stimulus was supra-threshold, regardless of its location. However, this was not the case when the visual stimulus was at threshold. In this case, the influence of the visual cue was apparent only when the two cues were spatially coincident and resulted in an enhancement of stimulus localization. These data suggest that the brain uses multiple strategies to integrate multisensory information.     

The role of the nucleus basalis magnocellularis in fear conditioning consolidation in the rat

The nucleus basalis magnocellularis (NBM) is known to be involved in the memorization of several conditioned responses. To investigate the role of the NBM in fear conditioning memorization, this neural site was subjected to fully reversible tetrodotoxin (TTX) inactivation during consolidation in adult male Wistar rats that had undergone fear training to acoustic conditioned stimulus (CS) and context. TTX was stereotaxically administered to different groups of rats at increasing intervals after the acquisition session. Memory was assessed as the conditioned freezing duration measured during retention testing, always performed 72 and 96 h after TTX administration. In this way, there was no interference with normal NBM function during either acquisition or retrieval phases, allowing any amnesic effect to be due only to consolidation disruption. The results show that for contextual fear response memory consolidation, NBM functional integrity is necessary up to 24 h post-acquisition. On the other hand, NBM functional integrity was shown to be necessary for memory consolidation of the acoustic CS fear response only immediately after acquisition and not 24-h post-acquisition. The present findings help to elucidate the role of the NBM in memory consolidation and better define the neural circuits involved in fear memories.     

Substantia nigra role in fear conditioning consolidation

The substantia nigra (SN) is known to be involved in the memorization of several conditioned responses. To investigate the role of the SN in fear conditioning consolidation this neural site was subjected to fully reversible tetrodotoxin (TTX) inactivation during consolidation in adult male Wistar rats which had undergone fear training to acoustic CS and context. TTX was stereotaxically administered to different groups of rats at increasing intervals after the acquisition session. Memory was assessed as conditioned freezing duration measured during retention testing, always performed 72 and 96 h after TTX administration. In this way there was no interference with normal SN function during either acquisition or retrieval phases, so that any amnesic effect could be due only to consolidation disruption. The results show that SN functional integrity is necessary for contextual fear response consolidation up to the 24-h after-acquisition delay. On the contrary SN functional integrity was shown not to be necessary for the consolidation of acoustic CS fear responses. The present findings help to elucidate the role of the SN in memory consolidation and better define the neural circuits involved in fear memories.