A machine-level software program for the generation of aversive conditioning schedules using the KIM-1 microprocessor

A microprocessor system can be used both to control aversive conditioning (classical, signaled and Sidman avoidance, and conflict) experiments and to acquire behavioral data in multiple subjects at a fraction of the cost of solid state systems. The software described in this paper can be used to program tones and shocks and count responses, independently, in up to 12 animals simultaneously.     

Manipulation of response-contingent unconditioned-stimulus intensity in human eyelid conditioning: A two-phase model analysis

Four groups of human subjects were given 360 classical eyeblink conditioning trials. All groups received the same UCS (unconditioned stimulus) intensity on[Formula: see text] (nonconditioned response) trials but differed in the intensity presented on CR trials. Response probability increased as a positive function of UCS intensity on CR trials. Phase 1 of the two-phase model was longer when no UCS was presented on CR trials, but did not differ in duration among the remaining three groups. Most subjects could be described with a single operator in Phase 2, the operator limit increasing as a positive function of CR-contingent UCS intensity. For subjects requiring different operator limits on CR and[Formula: see text] trials, the latter was lower with high CR-trial intensities but higher with low CR-trialintensities. The results were interpreted to be more consistent with drive theory than with "law-of-effect" or two-factor theories.     

Defensive burying, nest relocation, and pup transport in lactating female rats

A wire-wrapped wooden dowel was inserted through the wall of the nest compartment of a two-compartment box. There were four conditions. Some lactating female rats were shocked by the dowel when they first touched it, and some were not, after which the dowel was either immediately withdrawn from the chamber or left in place for the duration of the ensuing 30-min test period. Three defensive behaviours were observed during the tests: the mothers buried the shock source with bedding from the floor of the chamber, they transported their pups to the adjoining “safe” chamber, and they built a new nest in the safe chamber from material salvaged from their original nest. The shocked mothers that were confronted with the shock source throughout the test period displayed significantly more of each of these three defensive behaviours than did the mothers in the other three conditions. The methods used in this study provide a simple, reliable, safe paradigm for studying maternal defensive behaviour; the results indicate that the defensive capacities of the rat extend far beyond stereotypical flight, freeze, and fight responses, which have been the focus of most research on rodent defense.     

Balancing the ledger: An application of Nagy's theories to the study of continuity and change among generations

This study uses an interpretive interview method to examine the micro-processes of generational continuity and change among a group of social activists. Boszormenyi-Nagy's theory of responsibility between generations, alternative models outside the family, and choice are used to explain the instances of change. Implications for research and practice are addressed.     

Suicidal Behaviors in Surviving Monozygotic and Dizygotic Co‐Twins: Is the Nature of the Co‐Twin's Cause of Death a Factor?

Genetically informative samples can address hereditary and experiential influences on suicide‐related behaviors. The frequency of suicide‐related behaviors was compared in twins from two survivor groups: (1) those whose co‐twins' deaths were suicides (monozygotic [MZ]: n = 47; dizygotic [DZ]: n = 31), and (2) those whose co‐twins' deaths were nonsuicides (MZ: n = 347; DZ: n = 170). The frequency of suicide attempts among suicide survivors was significantly higher in MZ than DZ twins, while the frequency of suicide attempts among nonsuicide twin survivors did not differ between MZ and DZ twins. Twin concordance for suicide attempts more likely reflects a genetic predisposition than a behavioral reaction to the loss.     

Understanding the Progression from Early Alcohol Use Experimentation to Alcohol Use Disorder: Testing Vulnerability by Experience Interactions Using a Two-Part Latent Growth Curve Model

Most adolescents experiment with alcohol, but a smaller percentage advance to heavy alcohol use (AU) and AU disorder (AUD). Understanding for whom and how early risk leads to AUD is of interest to prevention, treatment, and etiology of AUD. Informed by developmental and behavioral neuroscience theory, the current study tested whether temperament (effortful control, surgency, and negative affect), peer AU (multi-reporter), and AU with parents’ permission interacted to distinguish youth who experiment with alcohol from those who escalate to AUD. Community adolescents (N?=?765, 53% female) were assessed annually for seven years (M_age?=?11.8, range: 10–13 at Year 1; M_age?=?18.7; range?=?17–20 at year 7). Temperament by early experience interactions were expected to predict amount of AU. Amount of AU was expected to mediate the relationship between the interactions and AUD symptoms (assessed at Years 3 and 7, M_age?=?13.8 and 18.7) above and beyond a range of confounds (e.g., problem behavior and parental AU and AUD). Supporting hypotheses, effortful control and surgency interacted with AU with parents’ permission and peer AU, respectively, to predict higher amount of AU (R²?=?0.47) and AUD symptoms (R²?=?0.03). Results support developmental and behavioral neuroscience theory. High surgency and low effortful control in conjunction with peer AU and AU with parents’ permission were associated with large effects on AU and moderate mediated effects through AU to AUD. AU with parents’ permission was risky at low and high effortful control and protective when peers used alcohol.

     

Single-Stage Prediction Models Do Not Explain the Magnitude of Syntactic Disambiguation Difficulty

The disambiguation of a syntactically ambiguous sentence in favor of a less preferred parse can lead to slower reading at the disambiguation point. This phenomenon, referred to as a garden-path effect, has motivated models in which readers initially maintain only a subset of the possible parses of the sentence, and subsequently require time-consuming reanalysis to reconstruct a discarded parse. A more recent proposal argues that the garden-path effect can be reduced to surprisal arising in a fully parallel parser: words consistent with the initially dispreferred but ultimately correct parse are simply less predictable than those consistent with the incorrect parse. Since predictability has pervasive effects in reading far beyond garden-path sentences, this account, which dispenses with reanalysis mechanisms, is more parsimonious. Crucially, it predicts a linear effect of surprisal: the garden-path effect is expected to be proportional to the difference in word surprisal between the ultimately correct and ultimately incorrect interpretations. To test this prediction, we used recurrent neural network language models to estimate word-by-word surprisal for three temporarily ambiguous constructions. We then estimated the slowdown attributed to each bit of surprisal from human self-paced reading times, and used that quantity to predict syntactic disambiguation difficulty. Surprisal successfully predicted the existence of garden-path effects, but drastically underpredicted their magnitude, and failed to predict their relative severity across constructions. We conclude that a full explanation of syntactic disambiguation difficulty may require recovery mechanisms beyond predictability.