Time travel,hyperspace and Cheshire Cats

H. G. Wells’ Time Traveller inhabits uniform Newtonian time. Where relativistic/quantum travelers into the past follow spacetime curvatures, past-bound Wellsians must reverse their direction of travel relative to absolute time. William Grey and Robin Le Poidevin claim reversing Wellsians must overlap with themselves or fade away piecemeal like the Cheshire Cat. Self-overlap is physically impossible but ‘Cheshire Cat’ fades destroy Wellsians’ causal continuity and breed bizarre fusions of traveler-stages with opposed time-directions. However, Wellsians who rotate in higher-dimensional space can reverse temporal direction without self-overlap, Cheshire Cats or mereological monstrosities. Alas, hyper-rotation in Newtonian space poses dynamic and biological problems, (e.g. gravitational/electrostatic singularities and catastrophic blood-loss). Controllable and survivable Wellsian travel needs topologically-variable spaces. Newtonian space, not Newtonian time, is Wellsians’ real enemy.     

Predicting educational achievement from genomic measures and socioeconomic status

The two best predictors of children's educational achievement available from birth are parents’ socioeconomic status (SES) and, recently, children's inherited DNA differences that can be aggregated in genome‐wide polygenic scores (GPS). Here, we chart for the first time the developmental interplay between these two predictors of educational achievement at ages 7, 11, 14 and 16 in a sample of almost 5,000 UK school children. We show that the prediction of educational achievement from both GPS and SES increases steadily throughout the school years. Using latent growth curve models, we find that GPS and SES not only predict educational achievement in the first grade but they also account for systematic changes in achievement across the school years. At the end of compulsory education at age 16, GPS and SES, respectively, predict 14% and 23% of the variance of educational achievement. Analyses of the extremes of GPS and SES highlight their influence and interplay: In children who have high GPS and come from high SES families, 77% go to university, whereas 21% of children with low GPS and from low SES backgrounds attend university. We find that the associations of GPS and SES with educational achievement are primarily additive, suggesting that their joint influence is particularly dramatic for children at the extreme ends of the distribution.     

Plattner's Arrow: Science and Multi-Dimensional Time

Might time be multi‐dimensional? In exploring this question, this paper uses a thought‐experiment about dimensionality, H. G. Wells' ‘The Plattner Story’. Plattner has his left and right sides transposed after a trip through a fourth spatial dimension, a change with independent empirical consequences. This example is then generalised to reversals of the directions of time and entropy. Finally, this thought‐experiment is related to relativistic theories of time and the possibility of preserving causality in a temporally multi‐dimensional framework.     

Parental use of escape extinctionand differential reinforcement to treat food selectivity.

Escape extinction combined with differential reinforcement for acceptance has been demonstrated to be an effective treatment for food selectivity when implemented by trained professionals in clinic settings. This study evaluated the efficacy of parent-implemented escape extinction in the child''s natural environment using video monitoring to train parents and assess intervention efficacy. Parents were able to use intervention to significantly increase bites accepted and decrease problem behavior.     

REPEATED ACQUISITION OF BEHAVIORAL CHAINS: RESPONSE SEQUENCES OR CONDITIONAL DISCRIMINATIONS?

The purpose of this study was to determine whether pigeons learn a sequence of positional responses or a series of conditional discriminations under a repeated-acquisition-of-behavioral-chains procedure. Three pigeons were trained under a repeated-acquisition procedure in which three different key colors served as stimuli correlated with the three steps in a chain. The order of presentation of the three stimuli was altered during the latter part of each test session after acquisition had occurred. If the pigeons had acquired a response sequence, the pattern of responding should remain the same as in the initial portion of the test session. However, if the pigeons had acquired a conditional discrimination, the response pattern should change in accordance with the changed order of the key colors. Although the results of this study do not rule out the possibility that the subjects acquired, to some degree, a response sequence, the results suggest that the behavior of pigeons under a repeated-acquisition-of-behavioral-chains procedure is controlled primarily by conditional discriminative stimuli.     

Drugs and punished responding II: d-amphetamine-induced increases in punished responding

The effects of d-amphetamine on punished responding were studied in two experiments. In Experiment I, pigeons responded under a multiple fixed-ratio 30 response fixed-interval 5-min schedule of food presentation with 60-sec limited holds in both components. Each response was punished with electric shock, the intensity of which was varied systematically. In Experiment II, another group of pigeons responded under a multiple fixed-interval 5-min fixed-interval 5-min schedule of food presentation with 40-sec limited holds. Each response was punished with shock during one component, and every thirtieth response was punished in the other component. d-Amphetamine increased overall rates of punished responding only rarely under any of the punishment conditions; however, response rates within the fixed-interval when rates were low were increased by d-amphetamine when the shock intensity was low (Experiment I), or when responses produced shock intermittently (Experiment II). The data suggest that the effects of d-amphetamine on punished responding depend on the control rate of responding, the punishment intensity, the punishment frequency, and the schedule of food presentation.     

Average uncertainty as a determinant of observing behavior

After discrimination training on a multiple variable-interval extinction schedule of food reinforcement, pigeons were placed on the uncued or mixed version of the same schedule and allowed to make an optional “observing response” that converted the uncued schedule to the corresponding cued schedule by providing a 20-sec exposure to the appropriate discriminative stimulus. The schedule consisted of one hundred 40-sec components, and the probability that any one of them would be a variable-interval component was systematically varied between 0.00 and 1.00. The results showed that the amount of observing behavior was an inverted “U” function of the probability of the variable-interval component. Few observing responses occurred at probabilities of 0.00 or 1.00, and maximum responding occurred at a value less than 0.50.     

Reinforcement contingencies maintaining collateral responding under a DRL schedule

Two-key conjunctive schedules were studied with one key (food key) under a differential-reinforcement-of-low-rate 20-sec schedule, while the consequences of responding on another key (collateral key) were varied. When food depended not only upon a food-key interresponse time in excess of 20 sec, but also upon the occurrence of one or more collateral-key responses during the food-key interresponse time, the rate of collateral-key responding was low and food-key interresponse times rarely exceeded 20 sec. When collateral-key responses could produce a discriminative stimulus correlated with the availability of food under the DRL schedule, the discriminative stimulus functioned as a conditioned reinforcer to maintain higher rates of collateral-key responding, and the spacing of food-key responses increased. If the occurrence of the discriminative stimulus was independent of collateral-key responses, the rate of collateral-key responding was again low, but the spacing of food-key responses was still controlled by the discriminative stimulus. Both the conditioned reinforcer and the explicit reinforcement contingency could maintain collateral-key responding, but the adventitious correlation between collateral-key responses and the delivery of food could not maintain very much collateral-key responding. The pattern of responding on the food-key was determined to a much greater extent by the correlation between the discriminative stimulus and the delivery of food than by the pattern of responding on the collateral key.     

Effects of d-amphetamine and caffeine on schedule-controlled and schedule-induced responding.

The effects of d-amphetamine and caffeine were studied on rates and patterns of lever pressing and schedule-induced licking under fixed-interval schedules of food pellet presentation. In addition, the effects of caffeine were studied on lever pressing and licking under a multiple fixed-ratio fixed-interval schedule. Caffeine reduced mean overall rates of licking at lower doses than it reduced mean overall rates of pressing under the fixed-interval schedules, but the effects of caffeine on both licking and lever pressing depended largely on the control rate of responding. d-Amphetamine reduced mean overall rates of lever pressing and licking at about the same dose, but the effects of d-amphetamine also were a function of the control rate of responding.