Avoidance learning facilitates temporal processing in the primary auditory cortex

The primary auditory cortex is now known to be involved in learning and memory, as well as auditory perception. For example, spectral tuning often shifts toward or to the frequency of the conditioned stimulus during associative learning. As previous research has focused on tonal frequency, less is known about how learning might alter temporal parameters of response in the auditory cortex. This study addressed the effects of learning on the fidelity of temporal processing. Adult male rats were trained to avoid shock that was signaled by an 8.0 kHz tone. A novel control group received non-contingent tone and shock with shock probability decreasing over days to match the reduced number of shocks received by the avoidance group as they mastered the task. An untrained (nai ve) group served as a baseline. Following training, neuronal responses to white noise and a broad spectrum of tones were determined across the primary auditory cortex in a terminal experiment with subjects under general anesthesia. Avoidance conditioning significantly improved the precision of spike-timing: the coefficient of variation of 1st spike latency was significantly reduced in avoidance animals compared to controls and nai ves, both for tones and for noise. Additionally, avoidance learning was accompanied by a reduction of the latency of peak response, by 2.0-2.5 ms relative to nai ves and approximately 1.0 ms relative to controls. The shock-matched controls also exhibited significantly shorter peak latency of response than nai ves, demonstrating the importance of this non-avoidance control. Plasticity of temporal processing showed no evidence of frequency specificity and developed independently of the non-temporal parameters magnitude of response, frequency tuning and neural threshold, none of which were facilitated. The facilitation of temporal processing suggests that avoidance learning may increase synaptic strength either within the auditory cortex, in the subcortical auditory system, or both.     

Why modal fictionalism is not self-defeating

Gideon Rosen’s [1990 Modal fictionalism. Mind, 99, 327–354] Modal Fictionalist aims to secure the benefits of realism about possible-worlds, whilst avoiding commitment to the existence of any world other than our own. Rosen [1993 A problem for fictionalism about possible worlds. Analysis, 53, 71–81] and Stuart Brock [1993 Modal fictionalism: A response to Rosen. Mind, 102, 147–150] both argue that fictionalism is self-defeating since the fictionalist is tacitly committed to the existence of a plurality of worlds. In this paper, I develop a new strategy for the fictionalist to pursue in response to the Brock–Rosen objection. I begin by arguing that modal fictionalism is best understood as a paraphrase strategy that concerns the propositions that are expressed, in a given context, by modal sentences. I go on to argue that what is interesting about paraphrastic fictionalism is that it allows the fictionalist to accept that the sentence ‘there is a plurality of worlds’ is true without thereby committing her to the existence of a plurality of worlds. I then argue that the paraphrastic fictionalist can appeal to a form of semantic contextualism in order to communicate her status as an anti-realist. Finally, I generalise my conception of fictionalism and argue that Daniel Nolan and John O’Leary-Hawthorne [1996 Reflexive fictionalisms. Analysis, 56, 26–32] are wrong to suggest that the Brock-Rosen objection reveals a structural flaw with all species of fictionalism.

Sex differences in the personal costs and benefits of relational and physical aggression in high school

While recent research using peer ratings demonstrates positive relations between youth's reputations for aggression and popularity, it is not clear whether aggressive youth themselves make these links. Using youth's self‐reports, this study assessed the associations of relational and physical aggression with indicators of both personal gains in peer relations (perceived popularity and receipt of prosocial attention) and personal costs in terms of retaliation or depressive responses (peer victimization and depressive symptoms) in a large sample (n=455) of eighth‐ to tenth‐grade students. Regression analyses reveal that more relationally aggressive youth report more prosocial attention but also more relational (but not physical) victimization. In contrast, more physically aggressive youth report more depressive symptoms and physical (but not relational) victimization. Findings suggest that some costs of aggression (victimization) are higher for boys while others (depressive symptoms) are greater for girls. Group differences were also found for aggressive, victimized, and aggressive/victimized youth compared to the typical low aggressive/low victimized youth. These data suggest that the costs of relational and physical aggression may outweigh benefits except for aggressive non‐victimized boys. Aggr. Behav. 32:409–419, 2006. © 2006 Wiley‐Liss, Inc.     

Social networking site use: Linked to adolescents' social self‐concept,self‐esteem,and depressed mood

Adolescents spend a substantial amount of time using social networking sites (SNSs); however, little is known regarding whether such use is associated with indicators of adjustment. The present study employed a multidimensional measure of SNS use to investigate the link between Australian adolescent SNS use and indicators of adjustment. Youth (N = 1,819, 55% female) from 34 diverse high schools across Western Australia were surveyed. The results showed that frequency of SNS use was linked to higher social self‐concept while investment in SNSs was associated with lower self‐esteem and higher depressed mood. Furthermore, having an SNS was linked to more negative indicators for female adolescents compared with male adolescents, although the link between frequency of use and investment in SNSs to indicators of adjustment was not moderated by gender. The present study highlights the complexity of the relationship between adolescent SNS use and indicators of adjustment, and offers insight into the diverse types of adolescent use of SNSs.     

When You Care Enough to Do Your Very Best: Genetic Counselor Experiences of Compassion Fatigue

Compassion fatigue is a phenomenon that occurs when a caregiver feels overwhelmed by repeated empathic engagement with distressed clients (Figley, 2002). Research demonstrates its existence among nurses, physicians, and mental health professionals, but to date no published study has specifically investigated the nature and prevalence of compassion fatigue among genetic counselors. The present study was an initial attempt to identify and describe the phenomena in genetic counseling by conducting focus group interviews with 12 genetic counselors. Data analysis yielded several themes: a) compassion fatigue occurs and may compromise professional and personal functioning; b) prevalent triggers include delivering bad news and difficult patient issues (e.g., terminal illness, anger, psychopathology); c) effective coping strategies include consulting with colleagues, setting boundaries, and humor; and d) risk factors include personality characteristics and traumatic memories. Training, practice, and research recommendations are provided.