The nature of prolonged word search

Two alternative hypotheses were considered concerning the process of prolonged search for an uncommon word in response to hearing its definition. One alternative is that a conscious retrieval effort brings the target progressively closer to threshold. The second is that the retrieval process is a random neural exploration outside of conscious control. A tachistoscopic probe was devised to compare word recognition thresholds after 10 sec versus 30 sec of presumed search time. Results failed to show a difference between the two delay conditions and were interpreted as inconsistent with the first alternative but consistent with the second.     

Chronic stress, leukocyte subpopulations, and humoral response to latent viruses

Psychological stress has been shown to affect immune system status and function, but most studies of this relationship have focused on acute stress and/or laboratory situations. The present study compared total numbers of leukocytes and lymphocyte subpopulations (determined by flow cytometry) and antibody titers to latent and nonlatent viruses among a group of chronically stressed individuals living near the damaged Three Mile Island (TMI) nuclear power plant with those of a demographically comparable control group. Urinary catecholamine and cortisol levels were also examined. Residents of the TMI area exhibited greater numbers of neutrophils, which were positively correlated with epinephrine levels. The TMI group also exhibited fewer B lymphocytes, T-suppressor/cytotoxic lymphocytes, and natural killer cells. Antibody titers to herpes simplex were significantly different across groups as well, whereas titers to nonlatent rubella virus as well as IgG and IgM levels were comparable.     

Response to commentaries on “A neurobiological model for near-death experiences”

This work has received financial support from FONDECYT (Project 1111-88). The authors also acknowledge the helpful comments of Dr. Bruce Cassels.     

Sex differences in occupational values

In order to examine sex differences in occupational values, college women and men rated the importance of 18 job characteristics for their career choice. In addition, they indicated which three were the most important and which three were the least important. The findings showed that, in comparison to males, females attached greater importance to a large variety of values, and these results are discussed in relation to career choice.This research was supported by a grant from the University of Connecticut Research Foundation.     

Recall by expert medical practitioners and novices as a record of processing attention

Using recall of clinical protocols as a measure of expertise in medicine has yielded disappointingly small effects. Experiments using recall of clinical laboratory data are presented to provide an explanation. In one experiment, subjects either deliberately memorized or first diagnosed and then were incidentally asked for memory. With incidental instructions, experts recalled over twice as much data as did students, but with memorization instructions, student performance approximated that of experts. Experts also showed a large advantage over students in incidental recall of data that were not relevant to the problem solution. These results suggest that expert processing in this "discrete, independent inputs" domain requires effortful analysis with minimal reliance on default values, rather than relatively effortless pattern perception reported in highly visual areas of expertise. For this area, intentional memory is a misleading measure of expertise. However, incidental memory is a valuable measure of processing during diagnosis.     

Twenty-four-hour sleep-wake patterns in a nursing home population

Sleep-activity patterns were objectively recorded over a 24-hr period in 19 elderly nursing home residents. On average, both sleep and wake times were observed during every hour of the 24 recorded hours; however, the sleep pattern of the residents was fragmented so that they rarely experienced even a single hour of consolidated time spent sleeping. It is hypothesized that several independent factors, including compensation for lost sleep, increased total time in bed, weakening of social constraints, and deterioration of the circadian sleep-wake rhythm, are interacting to produce this increase in sleep fragmentation.     

Perioral somatosensory determinants of nursing behavior in Norway rats (Rattus norvegicus)

Prior to assuming the upright crouching posture over their pups during nursing bouts, lactating rats typically engage in several oral behaviors, including nuzzling, licking and rearranging pups. By acutely depriving dams of various aspects of perioral stimulation from pups (with anesthesia of the mystacial pads or of the tongue, with mouth suturing, or with muzzling), we found the following: (1) Distal stimulation from pups maintains proximity-seeking behavior, but is insufficient to stimulate nursing behavior. (2) Lack of tongue feedback decreases pup licking and hastens the onset of crouching. (3) Snout, but not tongue, contact with pups is required for hovering over them. (4) The position of the dam while hovering over her litter enables the pups to gain access to her ventrum, thereby provoking her upright, crouching posture. (5) Older pups are capable of bypassing the dam's perioral attentions and stimulating crouching directly by burrowing under the dam's ventrum.