Extinction of Pavlovian fear conditioning in rats is a useful model for therapeutic interventions in humans with anxiety disorders. Recently, we found that delivering extinction trials soon (15 min) after fear conditioning yields a short-term suppression of fear, but little long-term extinction. Here, we explored the possible mechanisms underlying this deficit by assessing the suppression of fe...

Although exposure therapy is an effective treatment for anxiety disorders, fear sometimes returns following successful therapy. The Rescorla–Wagner model predicts that presenting two fear-provoking stimuli simultaneously (compound extinction) will maximize learning during exposure and reduce the likelihood of relapse. Participants were presented with either single extinction trials only or sing...

Fear extinction is a central model for the treatment of anxiety disorders. Initial research has reported that the single presentation of a conditioned stimulus prior to extinction learning can permanently block the return of fear. However, only few studies have explored this issue and could not always replicate the findings. The present study examined human fear extinction using a four-day desi...

Adolescent rats exhibit impaired extinction retention compared to pre-adolescent and adult rats. A single nonreinforced exposure to the conditioned stimulus (CS; a retrieval trial) given shortly before extinction has been shown in some circumstances to reduce the recovery of fear after extinction in adult animals. This study investigated whether a retrieval-extinction procedure would reduce the...

in order to study the effects of sowing date and plant density on forage yield and some morphological characteristics of corn, an experiment was conducted in gorgon research station in 2008. in this experiment two sowing date (18 april and 21 june) and six plant densities (25000, 45000, 65000, 85000, 105000, and 125000 plant per hectare) were evaluated in form of factorial experiment (2×6) with...

marginal zone lymphoma (mzl) accounts for between 5% and 17% of all non-hodgkin lymphomas (nhl). w e reported a rare case of marginal zone lymphoma presenting with bilateral ear erythema and swelling. the case was a 79-year-old man who suffered from progressive bilateral ear erythema and swelling since 2 years ago. physical examination was remarkable for erythmatous, edematous and non-tender au...

in this study, generation of the transient evoked ooacoustic emissions in human ear has been simulated using a new electroacoustic model. the method of state variables was adopted to calculate the auditory model, and numerical integration methods have been used to solve differential equations in matlab. simulation results have been compared with the real data. in this study, latency curves, fre...

Extinction of auditory fear conditioning is thought to form a new memory. We previously found that rats with vmPFC lesions could extinguish fear to the tone within a session, but showed no recall of extinction 24 h later. One interpretation is that the vmPFC is the sole storage site of extinction memory. However, it is also possible that lesioned rats were unable to retrieve extinction memory s...