The lickometer: A simple device for the analysis of licking as an operant

A lickometer for recording dry (unreinforced) tube licking in rats is described. As opposed to the conventional drinkometer, where each lick produces fluid, the lickometer provides the possibility for automatically programmed intermittent reinforcement of (dry) licking, and it does not involve electrical connections through the chamber floor. Comparison of licking and leverpressing with equivalent reinforcers and under equivalent schedules of reinforcement is thus feasible.     

Instrumentation designed to simulate the effects of prisms used in studies of visual rearrangement

A system is described which simulates some of the visual rearrangements and changes in sensorimotor relations that occur when experimental subjects move their eyes while looking through a contact lens with a prism attached. The simulated system is more convenient than a system based on the use of a contact lens, and it is based on measures of eye movement that are important in research on the perceptual effects of visual rearrangement. The effects that occur are reviewed in this paper. We also show in detail how the artificial system, which has an eye movement monitor interfaced with a computer and display, simulates the former effects. The data show that experimental subjects who experience visual rearrangement by simulated means manifest the same kind of perceptual adaptation produced in studies in which visual rearrangement is generated by means of a prism mounted on a contact lens.     

Development of the visual placing response in the human infant

The development of the visual placing response was studied in the human infant using an apparatus that controlled the visual stimulus (texture density of patterns) and the depth at which stimuli were presented. The visual placing response was found to be nearly an all-or-none response having an acute onset at between 170 and 190 days of age. The response is identified in the human infant by rigid extension of the hands and arms, characteristically with the fingers fanned. Shortly after it develops, the response appears to be visually mediated and is well differentiated with respect to increasing depth. In contrast, the older infants showed less well differentiated visual placing, tending to respond to all depths equally. The results suggest that there are two phases in the development of the response. The first phase is the initial acquisition of the response and is determined largely by visual depth. The second phase occurs later in development, near the time of walking, and seems to be determined by several factors, including both texture density and depth.     

Laterality differences for word identification in bilinguals

Twenty-three Spanish-English bilinguals were tachistoscopically presented with four-letter common nouns. They viewed 20 word pairs, first in their native language, then in the other, for 40 msec under simultaneous bilateral exposure. This paradigm has previously shown a strong right visual field and therefore left hemisphere superiority for words in a single language. The results show a word identification advantage in the right visual field. This indicates a left hemisphere advantage for processing of both languages, regardless of which was learned first. There are nevertheless wide individual differences in the number of bilinguals showing the expected asymmetry, as compared with monolinguals. There may be a trend, therefore, for less unilaterality of language function in bilinguals, although both languages are seen as being equally lateralized.     

Goal feedback from whom? A physical activity intervention using an N-of-1 RCT

Objective: Adolescents are not meeting the recommended guidelines for physical activity. Social support and self-regulatory skills are two factors known to impact physical activity and sedentary behaviour. The study sought to examine how targeting feedback as part of a self-regulatory process could increase physical activity, and the individual who should be providing the feedback.

Design: The study utilised an aggregated N-of-1 RCT which allows for an iterative process of intervention development, and examines variability within participants to answer the question for whom did the intervention work. Ten adolescents (ages 13–18) set a daily physical activity goal. Adolescents received a SMS text message providing feedback on goal attainment daily from a parent, peer, behavioural health specialist; or no text message (control).

Main Outcome Measures: A bioharness heart rate monitor assessed heart rate as proxy for goal attainment. Adolescents also self-monitored their physical activity in the Calorie Counter and Diet Tracker by MyFitnessPal^TM app (commercially available).

Results: Intervention demonstrated a significant effect for 30% of the sample in increasing MVPA (M_increase = 52 min), with no significant effect on sedentary behaviour.

Conclusion: A single occasion of text messaging from the right person can produce changes, however, careful consideration should be given to who provides the feedback.     

Incremental validity of the Psychopathy Checklist facet scores: predicting release outcome in six samples

The incremental validity of the 4 facet scores (Interpersonal, Affective, Lifestyle, Antisocial) of the Psychopathy Checklist-Revised (PCL-R; R. D. Hare, 1991, 2003) and the Psychopathy Checklist: Screening Version (PCL:SV; S. D. Hart, D. N. Cox, & R. D. Hare, 1995) was evaluated in 6 forensic/correctional samples with average follow-ups ranging from 20 weeks to 10 years. Results indicated that whereas Facet 4 (Antisocial) achieved incremental validity relative to the first 3 facets (Interpersonal, Affective, and Lifestyle) in predicting recidivism in all 6 samples, a block of the first 3 facets achieved incremental validity relative to the 4th facet in only 1 sample. Thus, although there was consistent support for the incremental validity of Facet 4 above and beyond the first 3 facets, there was minimal support for the incremental validity of Facets 1, 2, and 3 above and beyond Facet 4. The implications of these findings for the psychopathy construct in general and the PCL-R/SV in particular are discussed.