Perceptual learning by preschool children using stimuli with varying proportions of common elements.

The effect of preexposure to visual stimuli on subsequent discrimination was studied in 17 girls and 23 boys, ages 53 to 61 mo., using a test in which a sample stimulus had to be identified from a set of comparison stimuli. Preexposure significantly facilitated discrimination. This facilitation was more noticeable between stimuli which shared a large proportion of common elements. The results were consistent with an associative theory of the representation of stimuli suggested by McLaren, Kaye, and Mackintosh in 1989, and implications are considered for teaching.

Does pre-incisional thoracic extradural block combined with diclofenac reduce postoperative pain after abdominal hysterectomy?

In a double-blind, randomized study, we investigated 40 patients undergoing abdominal hysterectomy; patients received 0.5% plain bupivacaine 20 ml via a low thoracic extradural catheter and a diclofenac suppository (100 mg), either 30 min before incision (group 1) or 30 min after incision (group 2). All patients received a standard general anaesthetic and no opioid was used before or during operation. Postoperative analgesic requirements were measured using a patient-controlled analgesia (PCA) system. Pain was assessed using a visual analogue scale (VAS) and a verbal pain score (VPS) on movement up to 48 h after operation. There was no significant difference in the time to first request for morphine but consumption of morphine was significantly greater in group 1 at all times except 24 h. There were no significant differences in VAS and VPS pain scores, although both scores were consistently higher in group 1. Patient satisfaction with the quality of analgesia, at 24 h, demonstrated no significant difference between the two groups. The combination of extradural block and diclofenac suppository given before operation did not appear to produce a clinically effective pre-emptive analgesic effect.