Fear of the warning signal during overtraining of avoidance

The present experiment assessed the Pavlovian properties of a tone used as a warning signal in discrete-trial avoidance training of rats by measuring its ability to block conditioning to a light when the tone-light compound signalled shock in a conditioned suppression procedure. The results, although based on a different measure of Pavlovian conditioning, confirmed those reported by Starr and Mineka (1977). After moderate levels of avoidance training, the tone blocked conditioning to the light; but after extended avoidance training it no longer did so, even though a yoked group exposed to the same Pavlovian relation between tone and shock showed no such decline.     

Exploring Thematic Nightmare Content and Associated Self‐Harm Risk

Nightmares have been shown to be robust predictors of self‐harm risk, beyond depressive symptoms and hopelessness at times. However, few studies have investigated associations between nightmare content and increased self‐harm risk. This study explored associations of thematic nightmare content with history of self‐harm, and risk of self‐harm phenomena the morning following a nightmare. A mixed‐method diary study was performed. Prospective nightmare reports were obtained from 72 participants. A total of 47 nightmare reports met inclusion criteria and were analyzed for themes using inductive thematic analysis. Chi‐square and bootstrap Pearson's correlation tests were performed to assess the associations between nightmare themes and self‐harm history, and risk of self‐harm phenomena following a nightmare. “ Powerlessness to Change Behavior” was associated with a history of self‐harm engagement, whereas “Financial Hardship” indicated reduced risk. Themes were not significantly associated with increased risk of self‐harm phenomena following a nightmare. Content may be of use in detecting lifetime history of self‐harm engagement, particularly in populations where disclosure is seen as taboo. However, nightmare symptom severity remains a better indicator of risk. Evidence for the utility of nightmare content in assessing immediate self‐harm risk is presently lacking. Replication with increased power is recommended.     

Latent learning and latent inhibition in maze discriminations

Rats were trained on an elevated maze where the rewarded alternative was defined either in terms of intra-maze or in terms of extra-maze cues. Pre-exposure to these cues produced a small latent or perceptual learning effect, i.e. facilitated subsequent learning of both problems, by comparison with animals pre-exposed to the maze with no cues present. Experiment 2 examined whether the effect of pre-exposure on intra-maze discrimination learning varied with the nature of the intra-maze cues. When positive and negative arms were further differentiated by painting the walls white and black, a marginal perceptual learning effect was turned into significant latent inhibition, i.e. a retardation of subsequent learning. Pre-exposure thus reliably facilitated extra-maze discrimnation learning, and its beneficial effects on intra-maze discrimination could be reversed by reducing the overlap between the intra-maze cues. Perceptual learning may therefore depend on requiring animals to discriminate between stimuli containing many common elements.