Biomedical subjects

W F Vitulli

Publications and source records attributed to W F Vitulli.

32 records · Page 2Linked to original sources

PubMed1992

Alcohol effects on behavioral thermoregulation with microwave radiation.

Ethanol may play an active role in modifying "set point" levels in conjunction with behavioral thermoregulation. A geometric series of doses of ethanol solutions was administered (ip) prior to fixed-interval 2-min. schedules of microwave reinforcement in rats tested in a cold environment. Four Sprague-Dawley rats were conditioned to regulate their thermal environment with 5-sec. exposures of MW reinforcement. Friedman's nonparametric test showed significant differences between ethanol doses, and Sign tests showed that moderate and high doses of ethanol suppressed operant behavior reinforced by MW radiation. Interactions between changes in "set-point" and discriminative properties of ethanol are discussed.

Animals↗

PubMed1991

Caffeine effects on behavioral thermoregulation.

Caffeine has a wide range of behaviorally active properties. Varying doses of caffeine solutions were administered (ip) prior to fixed-interval 2-min. schedules of microwave reinforcement in rats tested in a cold environment. Four Sprague-Dawley rats were conditioned to regulate their thermal environment with 5-sec. exposures of microwave reinforcement. Graphic descriptions showed that small doses of caffeine produced higher response rates for microwave heat than high doses of caffeine and saline controls, yet Friedman's nonparametric test showed no significant differences between dose levels. Synergism between thermogenic and discriminative properties of caffeine is proposed.

Animals↗

PubMed1990

Insulin and dextrose effects on fixed-interval behavioral thermoregulation in albino rats.

This study is a systematic replication of the effects of insulin doses on operant behavior reinforced (in an earlier study) by fixed-ratio schedules of microwave (MW) reinforcement. In this study, insulin and dextrose doses were administered (ip) prior to fixed-interval 2-min. schedules of MW reinforcement in rats tested in a cold environment. Six Sprague-Dawley rats were conditioned to regulate their thermal environment with 5-sec. exposures of MW radiation (SAR = 0.34 Watts/kg/(mW/cm2) under the FI-2' schedules. Humulin-regular insulin and 50% solutions of dextrose were administered (ip) alternately with saline control sessions for 8-hr. durations. A within-subjects, repeated-measures 4 x 8 x 3 factorial analysis of variance design showed that insulin doses suppressed operant responding for heat, which confirmed the results of the earlier study under a different schedule. In addition, high doses of dextrose had similar suppressing effects on operant responding for heat. The data are interpreted in terms of the discriminative properties of increased thermogenesis produced by the insulin and dextrose doses. The suppressing effects were more pronounced for the first two hours, yet they persisted for approximately six hours of the 8-hr. sessions.

Animals↗

PubMed1990

Short-term memory digit-span performance under auditory and visual contexts as a function of rate of digit presentation.

This exploratory investigation concerned the effects of both auditory and visual context variations on the immediate recall of a series of digits presented on a computer screen (CRT). 5 intensities of background noise and 5 background hues were presented randomly to 110 undergraduate volunteers as they studied 25 numerals ranging from 1 to 5 at rates of change of either 1 or 3 sec. per numeral timed from the onset of the previous numeral. A 2 x 2 x 5 mixed split-plot factorial analysis of variance gave a significant difference in mean immediate-recall scores between rates of digit presentation with better recall associated with the 3-sec. rate. There was no significant main effect in recall scores for auditory vs color contexts, yet a post hoc analysis of variance for successive stages followed by Scheffé comparisons showed that across auditory intensities, Stages 3 and 4 and 5 (combined) had significantly higher immediate recall scores than Stages 1 and 2 (combined). This improvement across stages was not found under the visual (color) series. There was a three-way interaction for modality-contexts x rates x levels explained by the partitioning of stages which differed for auditory and for visual contexts. Results are discussed in terms of effects of modality.

Adolescent↗

PubMed1989

Auditory and visual effects on solutions to computerized mathematics problems as a function of rate of digit presentation.

This exploratory investigation concerned the effects of both auditory and visual stimulus variations on the accuracy of mental solutions to addition problems presented on a computer screen (CRT). 5 intensities of background noise and 5 background hues were presented randomly to 123 undergraduate volunteers as they mentally summed 25 numerals ranging from 1 to 5 at rates of either 1 sec. or 3 sec. per numeral timed from the onset of the previous numeral. A 2 x 2 x 5 mixed splitplot factorial analysis of variance gave a significant difference in errors between rates of digit presentation with greater accuracy associated with the 3-sec. rate. There was no significant difference in mean errors for auditory vs color modalities, yet a post hoc Newman-Keuls paired-comparison test of decibel levels at the 1-sec. rate of digit presentation gave a significant difference in mean errors between 60-dB and 70-dB sound-pressure levels (SPLs) of white masking noise. Also, a post hoc F test on differences between successive stages indicated significant differences suggesting a "learning set." Comparisons between 'everyday' instances of these noise levels are made with implications for optimal computational environments.

Adult↗

PubMed1989

Adjunctive treatment with low-dose polymyxin B improves operant response rates and latency in infant rats with Haemophilus influenzae type b meningitis.

Polymyxin B given in conjunction with ampicillin protects infant rats against death from overwhelming Haemophilus influenzae type b infection. This study was undertaken to examine whether polymyxin B would mitigate the effects of brain damage caused by meningitis. Six- to 7-d-old Sprague-Dawley rats were infected subcutaneously into the nape with 10(7) cfu Haemophilus influenzae type b strain Eagan. This dose consistently caused bacteremia (1.2 X 10(5) cfu/mL) and meningitis (0.5 X 10(5) cfu/mL) in pilot studies. Twenty-four h after infection, all animals received intraperitoneal treatment consisting in either ampicillin alone (400 mg/kg X 4 q 3 h) repeated 12 h later, n = 15 or combined with polymyxin B (0.1 mg/kg/dose) n = 16. At age 2 mo, they were taken off ad libitum feeding and maintained at 80% of their wt. They were then conditioned to receive a food pellet by pressing a lever (continuous reinforcement). The next day, the time lapse between placement and pressing the lever for the first time was recorded (conditioned operant response or latency). Three wk later, the animals were put in the test chamber again and the time to press the lever (latency), as well as the time required to obtain 100 pellets (rate) were recorded. Animals who received polymyxin B had a significantly shorter reaction time; mean 34 s, SEM +/- 5.7 versus mean 88 s, SEM +/- 26.3, P less than or equal to 0.05 and performed significantly faster in obtaining 100 pellets; mean 925 s, SEM +/- 72.1 versus mean 1283 s, SEM +/- 126.3, p less than or equal to 0.02 (analysis of variance, Scheffé test).(ABSTRACT TRUNCATED AT 250 WORDS)

Ampicillin↗

PubMed1989

Insulin, exercise, and dietary effects upon behavioral thermoregulation in albino rats.

The objectives of this exploratory research were to assess the effects of insulin preparations (Humulin-regular and NPH) on operant behavior reinforced by schedules of microwave radiation in a cold environment and to measure changes in this thermoregulatory behavior as a function of exercise and food deprivation. Eight albino rats were conditioned to regulate their thermal environment with 6-sec. exposures of microwave (MW) radiation (SAR = 0.34 Watts/kg/(mW/cm2) under FR-1 and FR-10 schedules. Regular-insulin and NPH-insulin sessions were administered alternately with saline-control sessions for 8-hr. durations. Exercise in an activity wheel and 48 hr. of food deprivation (diet) were additional independent variables used to alter thermoregulation. Three randomized-block analysis of variance designs with repeated measures showed that insulin preparations resulted in a suppression of operant responding for heat, yet food deprivation increased rates of microwave responding. These data are interpreted in terms of functional relationships between ambient temperature changes, core body temperature, blood glucose fluctuations, and operant behavior.

Animals↗

PubMed1987

Behavioral effects of microwave reinforcement schedules and variations in microwave intensity on albino rats.

The objective of this exploratory investigation was to determine the interactive effects of fixed-ratio scheduling of microwave reinforcement in tandem with changes in microwave intensity. Nine albino rats were conditioned to regulate their thermal environment with microwave radiation while living in a Skinner (operant conditioning) Box in which the ambient temperature was about 27.13 degrees F at the beginning of the session. Each rat obtained a 6-sec. exposure of microwave radiation on a fixed-ratio schedule of MW reinforcement, the values of which varied from FR-1 to FR-30. Intensities of MW radiation were 62.5 W, 125 W, 250 W, and 437.5 W. Sessions lasted for 8 to 9 hr. over an approximate 13-mo. period. The effects of the intensity of microwave reinforcement varied as a function of the ratio value of the schedule used. Continuous reinforcement (FR-1) produced the lowest over-all rates, whereas FR-15, and FR-25 produced the highest over-all rates. Relatively higher thermal-behavior rates occurred under 62.5 W than under any of the other MW intensities for FR-1, FR-15, and FR-25, whereas FR-10 and FR-30 ratios produced intermediate rates of thermal responding which were constant for all values of MW intensity. These data are explained in terms of interactive effects between the "local" satiation or deprivation properties of the MW intensity and the ratio requirements of the schedule of MW reinforcement.

Animals↗

PubMed1986

Behavioral thermoregulation with microwave radiation of albino rats.

The objective of this exploratory study was to investigate the extent to which microwave radiation would reinforce operant behavior in a cold environment. A reversal-design with the single subject serving as its own control was used for testing the reinforcing properties of microwaves. Six albino rats were conditioned to produce 6-sec. pulses of microwave radiation within a refrigerated environment. The schedule of reinforcement was continuous (crf). Each lever press produced a 6-sec. output of microwave radiation. The intensity of radiation was varied across blocks of sessions in the reversal design. Microwave values used were as follows: 62.5 W, 125 W, 250 W, and 437.5 W. Sessions lasted from 8 to 9 hr. over an approximate 7-mo. period. Results showed that rates of operant responding varied as a direct function of microwave intensity. Relatively high mean rates were associated with moderate microwave intensity (250 W), whereas lower mean rates of responding were associated with extreme microwave intensities (62.5 W and 437.5 W) in the reversal design. These data are explained in terms of satiation and deprivation of the reinforcing value of microwave radiation.

Animals↗

PubMed1974